Split (3)

train · 130k rows

description stringlengths 2.98k 3.35M	abstract stringlengths 94 10.6k	cpc int64 0 8
FIELD OF THE INVENTION [0001] The current invention refers to a method for detecting point mutations of a nucleotide sequence by an improvement of the LAMP (loop amplification mediated polymerization) amplification method. As non limitative embodiment the invention refers to the G1849T mutation of the JAK2 gene. BACKGROUND [0002] Myeloproliferative disorders (MPD) are clonal disorders of haematopoietic progenitors, and include the classical MPD chronic myeloid leukaemia (CML), polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF), as well as chronic eosinophilic leukaemia (CEL), chronic myelomonocytic leukaemia (CMML), and systemic mastocytosis (SM) and others. In the past two decades, mutant alleles have been identified in CML, CMML, CEL and SM2-5, and in each case the causative mutation results in constitutive activation of tyrosine kinase signalling. The genetic causes of the most common MPD remained unknown until the identification of mutations that activate Janus kinase 2 (JAK2) signalling in most patients with PV, ET or PMF(1, 2, 3, 4). JAK2 is a member of the Janus family of cytoplasmic non-receptor tyrosine kinases, which also includes JAK1, JAK3 and TYK2. The mutation is a guanine-to-thymidine substitution at base 1489 (GenBank accession no. NM — 004972), which results in a substitution of valine for phenylalanine at amino acid 617 of the JAK2 protein (JAK2V617F), within the JH2 pseudokinase domain (5). Loss of JAK2 autoinhibition results in constitutive activation of the kinase, analogous to other mutations in MPDs and leukemia that aberrantly activate tyrosine kinases (6,7,8). Direct sequencing is only sensitive down to about 20% of mutant DNA in a wild-type background (9, 10). This issue is quite relevant to chronic myeloid disorders, where blood and marrow are often composed of a mixture of neoplastic and residual normal hematopoietic elements. Especially in the case of ET and MDS, in which phenotypically apparent gene mutations may be present in tiny clones comprising less than 10% of the total marrow cell population. James et al. (11) explored this issue specifically with respect to JAK2 1849 G-T by performing a series of mixing experiments with HEL erythroleukemia cells, which bear the JAK2 mutation, admixed with TF-1 erythroleukemia cells, which do not. They failed to detect the mutated allele when it was present in <5% of the total DNA. With homozygous mutant patient DNA diluted in DNA from a healthy person, sequencing was even less sensitive (10%) than it was with the cell lines (12). [0003] A common method used is the Amplification Refractory Mutation System (ARMS). It exploits the fact that oligonucleotide primers must be perfectly annealed at their 3 ′ ends for a DNA polymerase to extend these primers during PCR (12). By designing oligonucleotide primers that match only a specific DNA point mutation, such as that encoding JAK2 V617F, ARMS can distinguish between polymorphic alleles. Therefore, these techniques go by the alternative names of “allele-specific PCR” (AS-PCR) or “sequence-specific primer PCR.” The ARMS sensitivity is up to 1 to 2% (13) mutant DNA in a wild-type background. [0004] Real-time monitoring of PCR product accumulation during thermocycling can be of value as a semiquantitative method and DNA-melting curve assays can be used in conjunction with real-time PCR. Likewise, James et al. (14) compared fluorescent dye chemistry sequencing with two different real-time PCR based mutation detection systems, one using a LightCycler instrument (Roche Diagnostics) and the other using a Taqman ABI Prism 7500 machine (Applied Biosystems). These real-time PCR techniques detected 0.5 to 1% of HEL cell line DNA diluted in TF-1 cell line DNA and 2 to 4% of homozygously mutated patient DNA diluted in DNA from a healthy person. A Restriction Fragment Length Polymorphism (RFLP) analysis is possible since the JAK2 1849 G-T mutation abolishes a motif in the wild-type JAK2 sequence that is recognized by the restriction enzyme BsaXI. Although abolition of a restriction site is not as satisfying as creation of a new site, because a negative enzymatic cleavage reaction could be due either to absence of the mutation or to failure of the digestion procedure, it can be useful as a first pass analysis. Reported proportional sensitivity depends in part on the method used to detect the fragments and is approximately 20% mutant DNA in wild-type background (15, 16). [0005] Pyrosequencing is a method of rapid genotyping that depends on the liberation of pyrophosphate (PPi) whenever a dNTP is incorporated into a growing DNA chain during template-driven DNA polymerization (17). Pyrosequencing of JAK2 using the automated PSQ HS 96 system (Biotage, Uppsala, Sweden) has been attempted by several groups (17, 18) with dilution experiments similar to those described above showing a reported assay sensitivity of 5 to 10% mutant allele in a wild-type background. [0006] Several other mutation detection techniques have been described, including single stranded conformational polymorphism (SSCP) analysis, denaturing gradient gel electrophoresis (DGGE), denaturing high-performance liquid chromatography (DHPLC), single-nucleotide primer extension assays (Pronto), and others. In fact, DHPLC can detect the genomic DNA mutation underlying JAK2 V617F reliably, and it can detect mutations at a proportionality of <1 to 2%. However, DHPLC and the other techniques are either technically challenging or labor-intensive or both. They either do not allow high throughput at a cost suitable for a clinical laboratory (SSCP and DGGE) or require a considerable initial investment for equipment (DHPLC). [0007] Theoretically, protein-based techniques could also be used to detect the JAK2 V617F mutation, but these are generally cumbersome, and access to such resources is limited. Therefore, protein-based assays are usually not preferred if DNA- or RNA-based tests are feasible. [0008] EP1692281 discloses a method of JAK2 mutation detection based on PCR amplification. The method described presents several limitations. First of all the lower level of sensitivity, that allows detection of the mutant sequences of JAK2 down to 1% of the sample in the best cases. This sensitivity requires the enrichment of the mutants via granulocytes-isolation before extraction. This step is time consuming and labor-intensive and add about 2 hours to the already long procedures (from 2 to 5 hours) requested for the diagnosis. Furthermore, all the methods described are relatively labor intensive and expensive, often requiring specialized equipment that may not always be readily available. DESCRIPTION OF THE INVENTION [0009] The authors of the current invention have set up a novel method for the detection of point mutations that is selective and rapid. The method departs from the LAMP technology, as disclosed in EP 1020534 and depicted here in FIG. 1 . [0010] The assay is easy to be performed, since it needs simple instrumentation and produces the results in a single tube reaction. For these reasons it is also less expensive in respect to the other methods described above. [0011] The method overcomes the limitations underlined in the other techniques. It is more selective (down to 0.01% mutant sequences in wt background); it is isothermal and rapid, completing the diagnosis in a one hour reaction. [0012] The method refers to a simultaneous selective amplification and detection of a single base substitution in nucleic acids. [0013] Therefore it is an object of the invention a method for detecting the presence of a point mutation of a target nucleic acid molecule in a background of nucleic acid wild type molecules, comprising the steps of: [0014] a. obtaining a nucleic acid sample; [0015] b. contacting said nucleic acid sample, in appropriate reaction conditions, with a solution comprising a mixture of oligonucleotides and a DNA polymerase with strand displacement activity under hybridization conditions, wherein said mixture of oligonucleotides consists of primers suitable for a loop mediated isothermal amplification of the region of the nucleic acid molecule putatively including the point mutation, said primers comprising: i) two outer primers F 3 and B 3 ; ii) two inner primers FIP and BIP, where FIP includes two oligonucleotide sequences, F 2 and F 1 c , and BIP includes two oligonucleotide sequences, B 2 and B 1 c , where said inner primers FIP and BIP are able to recognize and hybridize to two different and opposite regions, F 2 c and B 2 c respectively, of the target nucleic acid molecule, where either the BIP primer is designed to hybridize downstream of the point mutation, or the FIP primer is designed to hybridize upstream of the point mutation, and in the case that the BIP primer is designed to hybridize downstream of the point mutation, then the FIP primer is designed to hybridize to the target sequence such that the point mutation is located in or downstream of the F 2 c sequence and upstream of F 1 c , or in the case that the FIP primer is designed to hybridize upstream of the point mutation, then the BIP primer is designed to hybridize to the target sequence such that the point mutation is located in or upstream of the B 2 c sequence and downstream of B 1 c; iii) a self-annealable extensible primer LB or LF respectively comprising:—a central loop sequence able to selectively recognize and hybridize to the region comprising the putative point mutation of the nucleic acid molecule only if the point mutation is present,—a 5 ′ end sequence and—a 3 ′ end sequence, said 5 ′ end and said 3 ′ end sequences being complementary to each other to form a stem, so that said central loop sequence has an higher hybridization affinity to the region comprising the putative point mutation of the nucleic acid molecule than the hybridization affinity of the 5 ′ end sequence to the 3 ′ end sequence, so that it results in annealing and amplification of the region comprising the putative point mutation of the nucleic acid molecule; iv) a non extensible moiety able to selectively recognize and hybridize to the WT sequence of nucleic acid molecule; [0020] c. incubating the resulting mixture at a constant temperature; [0021] d. detecting a signal indicative of amplification of the nucleotide molecule comprising the point mutation. [0022] In a preferred embodiment the point mutation is located in the region between F 2 and F 1 c or B 2 and B 1 c ; in an alternative preferred embodiment the point mutation is located in the region probed by B 2 or F 2 . [0023] In a preferred embodiment the sequence at the 5 ′ end and the sequence at the 3 ′ end of said self-annealable extensible primer is of at least 3 nucleotides. [0024] In a preferred embodiment the non extensible moiety is a peptide nucleic acid (PNA), preferably having at least 10 nucleotides. [0025] DNA and RNA have a deoxyribose and ribose sugar backbone, respectively, whereas PNA's backbone is composed of repeating N-(2-aminoethyl)-glycine units linked by peptide bonds. Purine and pyrimidine bases are linked to the backbone by methylene carbonyl bonds. PNAs are depicted like peptides, with the N-terminus at the first (left) position and the C-terminus at the right. Since the backbone of PNA contains no charged phosphate groups, the binding between PNA/DNA strands is stronger than between DNA/DNA strands due to the lack of electrostatic repulsion. [0026] In a most preferred embodiment said peptide nucleic acid (PNA) comprises a sequence of bases capable of hybridizing with the region including the putative point mutation resulting in double strand structures having respectively a melting temperature (Tm)=X with the wild type sequence and melting temperature (Tm)=Y with the mutant sequence, where Y<Incubation Temperature X and X is at least 5° C. higher than Y. [0027] In a preferred embodiment the non extensible moiety is a self-annealed non extensible primer, comprising a central loop sequence able to selectively recognize and hybrizide to the region comprising the wild type sequence of the nucleic acid molecule, a 5 ′ end sequence and a 3 ′ end sequence, said 5 ′ end and said 3 ′ end sequences being complementary to each other to form a stem, so that said central loop sequence has a higher hybridization affinity to the region comprising the wild type sequence of the nucleic acid molecule than the hybridization affinity of the 5 ′ end sequence to the 3 ′ and sequence, so that it results in annealing and blocking of the wt sequence. [0028] In a preferred embodiment the DNA polymerase with strand displacement activity is the Bst large fragment polymerase, or one of or a combination of: Bca (exo-), Vent, Vent (exo-), Deep Vent, Deep Vent (exo-), φ29 phage, MS-2 phage, Z-Taq, KOD, Klenow fragment. [0029] In a preferred embodiment the constant temperature is comprised between 62° C. and 67° C. [0030] In a preferred embodiment the signal indicative of amplification of the nucleotide molecule comprising the point mutation is detected by turbidimetry. Alternatively the signal indicative of amplification of the nucleotide molecule comprising the point mutation is detected by fluorescence. [0031] In a preferred embodiment the nucleic acid molecule comprises the region of the human JAK2 gene (GenBank accession no. NM — 004972), putatively having the point mutation, guanine-to-thymidine substitution at base 1489 (G1489T). Preferably F 2 and F 1 c are in position 1730-1750 and 1770-1795 respectively of the NM — 004972 gene sequence; B 2 is in position 1862-1884 of the NM — 004972 gene sequence and B 1 c is in position 1810-1840 of the NM — 004972 gene sequence. Most preferably the primers have the following sequences: [0000] F3 5'-GCATCTTTATTATGGCAGAGAG-3'; (Seq Id No. 1) B3 5'-TGCTCTGAGAAAGGCATTA-3'; (Seq Id No. 2) FIP 5'-GCTGCTTCAAAGAAAGACTAAGGAAATGGACAACAGTCAAACAAC-3'; (Seq Id No. 3) BIP 5'-GCTTTCTCACAAGCATTTGGTTTTAAATTAGCCTGTAGTTTTACTTACTCTC-3' (Seq Id No. 4) [0032] In a preferred embodiment the non extensible moiety is a PNA molecule, preferably having the structure: NH2 GAGTATGTGTCTGTGGA CONH2 . [0033] The method of the invention is applied also to other genes responsible for a pathology or an alteration, as i.e. kRAS, EGFR, and to SNPs. [0034] The invention will be described with reference to specific not limiting examples, including the following figures: [0035] FIG. 1 . LAMP Principle (Prior Art) [0036] The basic reaction is performed by 4 primers specific for 6 regions of a target genomic sequence. Internal primers anneal and extend on the target; the product is displaced in two steps by external primers (F 3 , B 3 ) and is shaped as a double stem-loop structure (starting structure) (panel A). The starting structure is simultaneously amplified from its free 3 ′ and by another internal primer (panel B). DNA concatamers built by inverted repeats of the initial module are progressively synthesized in an exponential fashion (panel C). [0037] FIG. 2 . LAMP “DUMB-BELL Strategy” Principle (Not Working Control) [0038] The primers set is designed with the F 1 c and B 1 c region complementary respectively to one base upstream and one base downstream the nucleotide of interest in position 1849. Furthermore, the 5 ′ end base of FIP and BIP is specific for the mutated nucleotide of JAK2 and both inner primers have a mismatched base at the third base from 3 ′ end. When the dumb-bell structure is formed, If the target in the reaction is WT, the mutant specific F 1 c and B 1 c will not anneal at its 3 ′ end resulting in no amplification. Differently, if mutant sequences are present in solution, the mutant specific F 1 c and B 1 c will perfectly anneal, becoming extensible by the polymerase. [0039] FIG. 3 . LAMP “Allele Specific Loop Primer Extension Strategy” Principle [0040] The only one loop primer in reaction has the last base in the 3 ′ end complementary to the mutant nucleotide T at position 1849 of the JAK2 gene. It also presents a mismatched base in the third base from the 3 ′ end. If the target in the reaction is WT, the mutant-specific loop primer will not anneal at its 3 ′ end resulting in no amplification. Differently, if mutant sequences are present in solution, the mutant specific loop primer will perfectly anneal, becoming extensible by the polymerase. [0041] FIG. 4 . LAMP “Self-Annealed Loop Primers Strategy” Principle [0042] Universal (mutant insensitive) set of primers comprising F 3 , B 3 , FIP and BIP to obtain a dumb-bell presenting the putative mutated nucleotide in the loop region. A particular loop primer designed to recognize the mutated base in the single strand dumb-bell structure is included, together with another modified loop primer complementary to the JAK2 wild type sequence and with the 3 ′ end not extensible. When the mutated JAK2 sequence is present (panel A), the modified mutant loop primer breaks its internal structure to anneal to the target, being consequently extensible by the polymerase: the amplification can proceed. When the wt sequence is present in the sample (panel B), the modified wt loop primer anneals to the wt target resulting in no amplification of the wt sequences and avoiding the aspecific binding of mutant loop primer (“silencing” effect). [0043] FIG. 5 . LAMP “Mutant Self-Annealed Loop Primer With PNA Strategy” Principle [0044] Universal (mutant insensitive) set of primers comprising F 3 , B 3 , FIP and BIP to obtain a dumb-bell presenting the putative mutated nucleotide in the loop region. A particular self annealed-loop primer designed to recognize the mutated base in the single strand dumb-bell structure is included, together with a PNA probe. The PNA is designed to be complementary to the loop region comprised between B 2 and B 1 c presenting the WT nucleotide. It forms a stable duplex only with the wt complementary sequence, preventing the annealing and extension of the mut-self-annealed loop primer and therefore suppressing the amplification (panel B). It does not anneal to the mut JAK2 sequence thanks to the lower affinity (panel A). [0045] FIG. 6 . Sensitivity of LAMP “DUMB-BELL Strategy” [0046] The reaction has been conducted on 7 e3 cps/ul wild type plasmid (square), on no-target control and on serial dilutions of mutant plasmid in water (from 7 e3 to 7 e1 cps/ul, rhomboidal points, and 7 e0 cps/ul, circle point). Each samples has been tested in triplicate. The error bars represent one standard deviation. The method amplify the specific target before the aspecific one until 7 e1 cps/ul concentration. The assay shows linearity between 7 e3 and 7 e1 cps/ul mutant sample. [0047] FIG. 7 . Sensitivity of LAMP “Allele Specific Mutant Loop Primer” [0048] The reaction has been conducted on 7 e3 cps/ul wild type plasmid (square point), on no-target control and on serial dilutions of mutant plasmid in water (from 7 e3 to 7 e1 cps/ul, rhomboidal points) . Each sample has been tested in triplicate. The error bars represent one standard deviation. The method amplify the specific target before the aspecific one until 7 e2 cps/ul concentration. The assay shows linearity between 7 e3 and 7 e1 cps/ul mutant sample. [0049] FIG. 8 . Selectivity of LAMP “Self-Annealed Loop Primer” [0050] The reaction has been conducted on 7 e3 cps/ul wild type plasmid (square point), on no-target control and on serial dilutions of mutant plasmid in wild type plasmid, in proportions from 75% to 1%, 35000 cps total amount of DNA per reaction. Each sample has been tested in triplicate. The error bars represent one standard deviation. The method amplify the specific target before the aspecific one until 1% dose (350 cps mut plasmid plus 34650 cps wt plasmid). The assay shows linearity between 100% and 1% mutant sample in wt background. [0051] FIG. 9 . LAMP “Self-Annealed Loop Primer with PNA” [0052] Test of the assay in presence and absence of PNA on mutated and wt plasmid (35000 cps each),In absence of PNA the WT plasmid is aspecifically amplified by the self-annealed mutant loop primer, with a delay of 5 min in respect to the specific mutated target. In presence of PNA, the WT plasmid is not amplified within one hour reaction by the self-annealed mutant loop primer. The amplification of the mutant plasmid is delayed of about 5 minutes. The PNA forms a stable duplex only with the wt complementary sequence preventing the annealing and extension of the mut-self-annealed loop primer and therefore suppressing the amplification within 1 hour of reaction. [0053] FIG. 10 . Selectivity of LAMP “Self-Annealed Loop Primer with PNA” [0054] Test of the assay on mutated plasmid (350000 cps), wild type plasmid (350000 cps) and on mutated plasmid serially diluted into wt plasmid in 1, 0.5, 0.1, 0.05 and 0.01% proportion. Error bars correspond to 1 standard deviation. The WT sample (350000 cps wt plasmid) is not amplified in one hour reaction. The specific mutant target is detected down to 0.01% mutant sequences in wt (35 copies tot mutant plasmid in 349650 copies of wt plasmid). The assay is linear down to 0.1% MUT (350 copies tot mutant plasmid in 349650 copies of wt plasmid). EXAMPLE 1 Materials, Methods and Results of the JAK2-Modified-LAMP “Dumb-Bell Strategy” [0055] Reagents [0056] JAK2 plasmids were synthesized by the supplier GeneArt (Regensburg, Germany) to contain the wild type or the mutant JAK2 sequence. In details: JAK2 plasmid which Insert corresponds to the sequence 1689-1722 of MN — 004972, including a G base at nucleotide1849, referred to as “wt plasmid”; JAK2 plasmid which Insert corresponds to the sequence 1689-1722 of MN — 004972 cloned, including a T base at nucleotide1849, referred to as “mut plasmid”. [0059] Primers: synthesized by the supplier Eurofins MWG Operon (Ebersberg, Germany) referred to as “primers”: [0000] GA211 (F3) 5' GTCAAACAACAATTCTTTGTACT 3' (Seq Id No. 5) GA212 (B3) 5' AGCTGTGATCCTGAAACTG 3' (Seq Id No. 6) GA216(FIP) 5'AATATACTCCATAATTTAAAACCAAATGCTTTCTTTCTTTGAAGCAGCAAGT 3' (Seq Id No. 7) GA220(BIP) 5'TTTTGTGGAGACGAGAGTAAGTAAAACTACATAAACAAAAACAGATGCTCTGA 3' (Seq Id No. 8) GA221 (LF) 5' GTGAGAAAGCTTGCTCATCAT 3' (Seq Id No. 9) GA222 (LB) 5' AGGCTTTCTAATGCCTTTC 3' (Seq Id No. 10) [0060] Reaction buffer: 100 mM Tris HCl pH 8.8, 50 mM KCl, 40 mM MgSO4, 50 mM (NH4)2SO4, 0.5% Tween, 5% DMSO “buffer 5×” [0061] dNTPs mix 25 mM (Fermentas), “dNTPs” [0062] Bst Large Fragment polymerase 8 U/ul (New England Biolabs), “Polymerase”Sterile apyrogen water (SALF Spa), “ddw” [0063] Procedure [0064] Sample Preparation [0065] Prepare reaction mix as follows: 0.2 μM outer primers (F 3 and B 3 ), 1.6 μpM inner primers (FIP and BIP), 0.8 uM loop primers (LF and LB), 1× buffer solution, 1.4 mM dNTPs mix, 8 U Bst Polymerase. Final volume of the reaction mix must be 4/5 of the total reaction volume (i.e. 20 μl reaction mix +5 μl sample). Always keep reagents on ice. Prepare the mix for at least 17 samples, comprising 3 negative control (7e3 cps/ul wild type plasmid), 12 positive control (3 samples 7e3 cps/ul mutant plasmid, 3 samples 7e2 cps/ul mutant plasmid , 3 samples 7e1 cps/ul mutant plasmid, 3 samples 7e0 cps/ul mutant plasmid) 1 no-target control. [0000] TABLE 1 sample mix composition Sample tube 1-3 4-6 7-9 10-12 13-15 16-19 Target to be Wt Mut Mut Mut Mut add (5 μl) plasmid plasmid plasmid plasmid plasmid 7e3 cps/ 7e3 cps/ 7e2 cps/ 7e1 cps/ 7e0 cps/ μl μl μl μl μl GA 211 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA212 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA 221 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 GA 221 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 GA 216 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 GA 220 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 Buffer 2.5 2.5 2.5 2.5 2.5 2.5 LAMP 5x Bst Polymerase 1 1 1 1 1 1 8 U/μl dNTPs 25 mM 1.4 1.4 1.4 1.4 1.4 1.4 Ddw to 20 μl 13.18 13.18 13.18 13.18 13.18 13.18 [0066] Dispense 20 μl of reaction mix in the strip. Keep the strips on ice. Always keep the reaction mix on ice from now on. [0067] Prepare serial dilutions of the target (“target dilutions”) from shipped solution (wt plasmid and mut plasmid). Shipped solution is a 710 10 copies/μl. Dilute initially the mutant plasmid to a 710 4 copies/μl in Tris 10 mM, then dilute serially to 7e3 cps/μl, 7e2 cps/μl, 7e1 cps/ and 7e0 cps/μl in Tris 10 mM. Dilute the wt plasmid to 710 3 copies/μl in Tris 10 mM. [0068] Add 5 μl of target dilutions to the strips, in triplicate. Add 5 μl of the target dilutions starting from the less concentrated one to the most concentrated one. Close all the tubes. [0069] Reaction [0070] The reaction follows the method scheme of FIGS. 1 and 2 . [0071] Program the turbidimeter (Teramecs) for incubation at constant temperature and real time monitoring of turbidity, in order to obtain a constant reaction temperature of 66° C. for 1 hour. [0072] Put the strips in the instrument immediately before the beginning of the programs. Start the program. [0073] Data Analysis [0074] Analyze the variation of absorbance in terms of a.u. (arbitrary units of absorbance) to find the threshold time for each sample analyzed. The threshold time is the minute at which the sample absorbance, after baseline subtraction, reaches the arbitrary unit value representing the threshold (in this case 0.1 a.u.). The threshold time reached by each samples is correlated with its Log of DNA copies/μl. [0075] Results [0076] “LAMP JAK2 Dumb-bell strategy” is based on the Eiken LAMP method for SNP detection (described in EP 1231281, 20, 21, 22, as well as on http://loopamp.eiken.co.jp/e/lamp/snps_anim.html). As shown in FIG. 2 , the primers set is designed with the F 1 c and B 1 c region complementary respectively to one base upstream and one base downstream the nucleotide of interest in position 1849. Furthermore, the 5 ′ end base of FIP and BIP is specific for the mutated nucleotide of JAK2 and both inner primers have a mismatched base at the third base from 3 ′ end. When the dumb-bell structure is formed, if the target in the reaction is WT, the mutant specific F 1 c and B 1 c will not anneal at its 3 ′ end resulting in no amplification because the mismatch at its 3 ′end should not be extensible. Differently, if mutant sequences are present in solution, the mutant specific F 1 c and B 1 c will perfectly anneal, becoming extensible by the polymerase. [0077] A shown in FIG. 6 , the assay was able to detect the mutant plasmid from 7e3 cps/μl to 7e0 cps/μl (35 copies tot mutant plasmid). It amplifies aspecifically the wt plasmid 7e3 cps/μl, not distinguishing the lower concentrations of mut plasmid from the aspecific target. The level of selectivity should be less than 1%, which is the limit shown by the other techniques in literature. With this approach we don't have any clear advantage. EXAMPLE 2 Materials, Methods and Results of the JAK2-Modified-LAMP “Allele Specific Loop Primer Extension Strategy” [0078] Reagents [0079] JAK2 plasmids were synthesized by the supplier GeneArt (Regensburg, Germany) to contain the wild type or the mutant JAK2 sequence. In details: which Insert corresponds to the sequence 1689-1722 of MN — 004972, including a G base at nucleotide1849, referred to as “wt plasmid” which Insert corresponds to the sequence 1689-1722 of MN — 004972 cloned, including a T base at nucleotide1849, referred to as “mut plasmid” [0082] Primers: synthesized by Eurofins MWG Operon, referred to as “primers”: [0000] JAKR5 (F3) 5' TCTATAGTCATGCTGAAAGTAGGAG 3' (Seq Id No. 11) JAKR2 (B3) 5' AAGGCATTAGAAAGCCTGTAGT 3' (Seq Id No. 12) JAKR7 (FIP) 5'ACAAAGAATTGTTGTTTGACTGTTGTCCATTGCATCTTTATTATGGCAGAGAGAA3' (Seq Id No. 13) JAKR8 (BIP) 5' AGTCTTTCTTTGAAGCAGCAAGTATGATGTTACTTACTCTCGTCTCCACAGA 3' (Seq Id No. 14) JAKR9 (LB) 5' AGCATTTGGTTTTAAATTATGGAGTA G GT T 3' (Seq Id No. 15) [0083] The underlined base corresponds to a mismatched nucleotide. The bold base corresponds to the mutated nucleotide at position 1849 of the JAK2 gene. [0084] Reaction buffer: 100 mM Tris HCl pH 8.8, 50 mM KCl, 40 mM MgSO4, 50 mM (NH4)2SO4, 0.5% Tween, “buffer 5×” [0085] dNTPs mix 2 mM (Fermentas), “dNTPs” [0086] Bst Large Fragment polymerase 8 U/ul (New England Biolabs), “Polymerase” [0087] Sterile apyrogen water (SALF Spa), “ddw” [0088] Procedure [0089] Sample Preparation [0090] Stock the primers in aliquots. It is better to store stock solutions at −20° C., while working dilutions should be stored at 4° C. [0091] Prepare reaction mix as follows: 0.2 μM outer primers (F 3 and b 3 ), 1.6 μM inner primers (FIP and BIP), 0.8 uM loop primer (LB), 1× buffer solution, 1.4 mM dNTPs mix, 8 U Bst Polymerase. Final volume of the reaction mix must be 4/5 of the total reaction volume (i.e. 20 μl reaction mix+5 μl sample). Always keep reagents on ice. Prepare the mix for at least 14 samples, comprising 3 negative controls (7e3 cps/ul wild type plasmid), 9 positive control (3 samples 7e3 cps/ul mutant plasmid, 3 samples 7e2 cps/ul mutant plasmid , 3 samples 7e1 cps/ul mutant plasmid) 1 no-target control. [0000] TABLE 2 sample mix composition Sample tube 1-3 4-6 7-9 10-12 13-15 16-19 Target to be Wt Mut Mut Mut Mut add (5 μl) plasmid plasmid plasmid plasmid plasmid 7e3 cps/ 7e3 cps/ 7e2 cps/ 7e1 cps/ 7e0 cps/ μl μl μl μl μl JAKR5 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 JAKR2 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 JAKR7 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 JAKR8 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 JAKR9 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 Buffer 2.5 2.5 2.5 2.5 2.5 2.5 LAMP 10x Bst Polymerase 1 1 1 1 1 1 8 U/μl dNTPs 25 mM 1.4 1.4 1.4 1.4 1.4 1.4 Ddw to 20 μl 14 14 14 14 14 14 [0092] Dispense 20 μl of reaction mix in the strip. Keep the strips on ice. Always keep the reaction mix on ice from now on. [0093] Prepare serial dilutions of the target (“target dilutions”) from shipped solution (wt plasmid and mut plasmid). Shipped solution is a 710 10 copies/μl. Dilute initially the mutant plasmid to a 710 4 copies/μl in Tris 10 mM, then dilute serially to 7e3 cps/μl, 7e2 cps/μl, 7e1 cps/μl in Tris 10 mM. Dilute the wt plasmid to 710 3 copies/μl in Tris 10 mM. Add 5 μl of target dilutions to the strips, in triplicate. Add 5 μl of the target dilutions starting from the less concentrated one to the most concentrated one. Close all the tubes. [0094] Reaction [0095] The reaction follows the method scheme of FIG. 3 . [0096] Program the turbidimeter (Teramecs) for incubation at constant temperature and real time monitoring of turbidity [0097] in order to obtain a constant reaction temperature of 65° C. for 1 hour. [0098] Put the strips in the instrument immediately before the beginning of the programs. Start the program. [0099] Data Analysis [0100] Analyze the variation of absorbance in terms of a.u. to find the threshold time for each sample analyzed. The threshold time is the minute at which the sample absorbance, after baseline subtraction, reaches the arbitrary unit value representing the threshold (in this case 0.1 a.u.). The threshold time reached by each samples is correlated with its Log of DNA copies/μl. [0101] Results [0102] This approach consists of a selective mutant amplification based on a mutant-specific loop primer ( FIG. 3 ). We designed a universal (mutant insensitive) set of primers comprising F 3 , B 3 , FIP and BIP to obtain a dumb-bell presenting the putative mutated nucleotide in the loop region comprised between B 2 and B 1 c . We therefore designed only one loop primer presenting the last base in the 3 ′ end complementary to the mutant nucleotide T at position 1849 of the JAK2 gene. It also presents a mismatched base in the third base from the 3 ′ end. [0103] If the target in the reaction is WT, the mutant-specific loop primer will not anneal at its 3 ′ end resulting in no amplification. Differently, if mutant sequences are present in solution, the mutant specific loop primer will perfectly anneal, becoming extensible by the polymerase. [0104] We tested this assay on the mutant plasmid from 7e3 cps/μl to 7e1 cps/μl. (35000 and 350 copies tot mutant plasmid) and on the aspecific wt plasmid ( 7 e 3 cps/μl), all in triplicate. The assay amplifies aspecifically the wt plasmid 7e3 cps/μl, not distinguishing the 7e1 cps/μl concentrations of mut plasmid from the aspecific target. The level of selectivity should be less than 1%, which is the limit shown by the other techniques in literature. With this approach we don't have any clear advantage. ( FIG. 7 ). EXAMPLE 3 Materials, Methods and Results of the JAK2-modified-LAMP “Self-annealing Loop Primer Strategy” [0105] Reagents [0106] JAK2 plasmids were synthesized by the supplier GeneArt (Regensburg, Germany) to contain the wild type or the mutant JAK2 sequence. In details: which Insert corresponds to the sequence 1689-1722 of MN — 004972, including a G base at nucleotide 1849, referred to as “wt plasmid” which Insert corresponds to the sequence 1689-1722 of MN — 004972 cloned, including a T base at nucleotide 1849, referred to as “mut plasmid” [0109] Primers: synthesized by Eurofins MWG Operon, referred to as “primers”: GA231 (F 3 ) 5 ′ GCATCTTTATTATGGCAGAGAG 3 ′ (Seq Id No. 16) GA232 (B 3 ) 5 ′ TGCTCTGAGAAAGGCATTA 3 ′ (Seq Id No. 17) GA233 (FIP) 5 ′ GCTGCTTCAAAGAAAGACTAAGGAAATGGACAACAGTCAAACAAC 3 ′ (Seq Id No. 18) GA234 (BIP) 5 ′ GCTTTCTCACAAGCATTTGGTTTTAAATTAGCCTGTAGTTTTACTTACTCTC 3 ′ (Seq Id No. 19) GA235 (LF) 5 ′GTCTCCACTGGAGTATGTGTCTGTGGAGAddC 3 ′ (Seq Id No. 20) the underlined base is the wild type nucleotide in position 1849 of the JAK2 gene. ddC stands for not-extensible dideoxy-cytosine. GA236 (LB) 5 ′ GTCTCCACTGGAGTATGTTTCTGTGGAGAC 3 ′ (Seq Id No. 21) the underlined base is the mutant nucleotide in position 1849 of the JAK2 gene. [0116] Reaction buffer: 100 mM Tris HCl pH 8.8, 50 mM KCl, 40 mM MgSO 4 , 50 mM (NH 4 ) 2 SO 4 , 0.5% Tween, “buffer 5×”dNTPs mix 25 mM (Fermentas), “dNTPs” [0117] Bst Large Fragment polymerase 8 U/ul (New England Biolabs), “Polymerase” [0118] Sterile apyrogen water (SALF Spa), “ddw” [0119] Procedure [0120] Sample Preparation [0121] Stock the primers in aliquots. It is better to store stock solutions at −20° C., while working dilutions should be stored at 4° C. [0122] Prepare reaction mix as follows: 0.2 μM outer primers (F 3 and B 3 ), 1.6 μM inner primers (FIP and BIP), 0.8 uM both self-annealed loop primers (not-extensible LF and LB), 1× buffer solution, 1.4 mM dNTPs mix, 8 U Bst Polymerase. Final volume of the reaction mix must be 4/5 of the total reaction volume (i.e. 20 μl reaction mix+5 μl sample). Always keep reagents on ice. Prepare the mix for at least 26 samples, comprising 3 negative controls (100% wild type plasmid, 7e3 cps/ul, 21 positive control (3 samples 100% (7e3 cps/ul) mutant plasmid, 3 samples 75% mutant plasmid diluted in wt plasmid, 3 samples 50% mutant plasmid diluted in wt plasmid, 3 samples 25% mutant plasmid diluted in wt plasmid, 3 samples 10% mutant plasmid diluted in wt plasmid, 3 samples 10% mutant plasmid diluted in wt plasmid, 3 samples 5% mutant plasmid diluted in wt plasmid, 3 samples 1% mutant plasmid diluted in wt plasmid, and one no target control. [0000] TABLE 3 sample mix composition Sample tube 1-3 4-6 7-9 10-12 13-15 16-19 Target to be Wt Mut Mut Mut Mut add (5 μl) plasmid plasmid plasmid plasmid plasmid 7e3 cps/ 7e3 cps/ 7e2 cps/ 7e1 cps/ 7e0 cps/ μl μl μl μl μl GA231 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA232 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA233 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 GA234 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 GA235 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 GA236 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 Buffer 2.5 2.5 2.5 2.5 2.5 2.5 LAMP 10x Bst Polymerase 1 1 1 1 1 1 8 U/μl dNTPs 25 mM 1.4 1.4 1.4 1.4 1.4 1.4 Ddw to 20 μl 13.8 13.8 13.8 13.8 13.8 13.8 [0123] Dispense 20 μl of reaction mix in the strip. Keep the strips on ice. Always keep the reaction mix on ice from now on. [0124] Prepare serial dilutions of the target (“target dilutions”) from shipped solution (wt plasmid and mut plasmid). Shipped solution is a 710 10 copies/μl. Dilute initially the mutant plasmid to a 710 4 copies/μl in Tris 10 mM, then dilute serially the mutant plasmid in wt plasmid to obtain the following concentrations of mutant sequences in wild type background: 75%, 50%, 25%, 10%, 5%, 1% (total amount per tube, 7e3 cps/μl). Add 5 μl of target dilutions to the strips, in triplicate. Add 5 ul of the target dilutions starting from the less concentrated one to the most concentrated one. Close all the tubes. [0125] Reaction [0126] The reaction follows the method scheme of FIG. 4 . [0127] Program the turbidimeter (Teramecs) for incubation at constant temperature and real time monitoring of turbidity, in order to obtain a constant reaction temperature of 65° C. for 1 hour. [0128] Put the strips in the instrument immediately before the beginning of the programs. Start the program. [0129] Data Analysis [0130] Analyze the variation of absorbance in terms of a.u. to find the threshold time for each sample analyzed. The threshold time is the minute at which the sample absorbance, after baseline subtraction, reaches the arbitrary unit value representing the threshold (in this case 0.1 a.u.). The threshold time reached by each samples is correlated with its Log of DNA copies/μl. [0131] Results [0132] This approach consists of a selective mutant amplification based on a particular loop primer design resulting in selective hybridization of such loop primer to the dumb-bell formed from the mutant sequence ( FIG. 4 ). We designed a universal (mutant insensitive) set of primers comprising F 3 , B 3 , FIP and BIP to obtain a dumb-bell presenting the putative mutated nucleotide in the loop region comprised between B 1 and B 2 . Other experiments were performed presenting the putative mutated nucleotide in the loop region into B 2 or comprised between B 2 and B 1 c , with no relevant differences. We included in the primer set a particular loop primer presenting a 8-bases sequence region at its 5 ′ end complementary to its own sequence in 3 ′ end. Consequently, this special loop primer forms an intra-molecular hairpin structure in equilibrium with its open form at the reaction temperature (65° C.). [0133] When the mutated JAK2 sequence is present, this modified loop primer breaks its internal structure to anneal to the target, thanks to the thermodynamic equilibrium (Tm between primer and specific target=65° C.). The loop primer annealed to the specific mutated target is consequently extensible by the polymerase: the amplification can proceed. [0134] When the wt sequence is present in the sample, the same loop primer (specific for the MUT JAK2 gene) presents a Tm with aspecific target (59° C.) lower than the intra-molecular hairpin structure (65° C.). This results in auto-sequestration of the modified loop primer that prefers to fold in the hairpin structure rather than to form a duplex with aspecific target, since the intramolecular forces are higher than the intermolecular ones. To limit the competition of the loop primer previously described for the wild type sequences likely to be present in large excess in the clinical sample, we added another modified loop primer characterized by a structure similar to the one previously described, but whit a sequence complementary to the JAK2 wild type sequence (with G base at position 1489). [0135] The 3 ′ end of this “competitor” loop primer is made not extensible by a modification ( 3 ′ dideoxy). The task of this competitor is to “silence” the wt and allow the specific mutant primer to find its target. [0136] When the “competitor” recognizes the specific wild type sequence, it breaks its intramolecular structure to anneal to the WT target, thanks to a higher affinity (Tm duplex wt target-wt modified loop primer=67° C.); The loop primer annealed to the wt target is not extensible, resulting in no amplification of the wt sequences. Since the reaction is conducted at constant temperature, the wt-loop primer will remain annealed to the wt sequences preventing aspecific annealing of the MUT loop primer. [0137] Differently, the “competitor” presents a Tm with its aspecific (mutant) target (62° C.) lower than the intra-molecular hairpin structure that it forms with itself (65° C.). This results in auto-sequestration of the modified loop primer that prefers to fold in the hairpin structure rather than to form a duplex with the aspecific target, since the intramolecular forces are higher than the intermolecular ones. [0138] The selectivity of this assay has been evaluated, performing the reaction on serial dilutions of mutant plasmid in wild type background ( FIG. 8 ). The selectivity achieved is significantly less than 1% (350 copies tot mutant plasmid in 34650 copies of wt plasmid). This approach has higher selectivity than the assays described in literature. [0139] The assay is linear between 100% mutant (35000 cps) and 1% mutant in 99% wild type (350 copies tot mutant plasmid in 34650 copies of wt plasmid). It allows detection and quantification of low percentage of mutant sequences in large amount of wt. It represents an improvement in respect of the other approaches shown in the previous slides and in respect to the methods described in literature. EXAMPLE 4 Materials, Methods and Results of the JAK2-modified-LAMP “Self-annealing Loop Primer Strategy with PNA” [0140] Reagents [0141] JAK2 plasmids were synthesized by the supplier GeneArt (Regensburg, Germany) to contain the wild type or the mutant JAK2 sequence. In details: which Insert corresponds to the sequence 1689-1722 of MN — 004972, including a G base at nucleotide 1849 , referred to as “wt plasmid” which Insert corresponds to the sequence 1689-1722 of MN — 004972 cloned, including a T base at nucleotide1849, referred to as “mut plasmid” [0144] Primers: synthesized by Eurofins MWG Operon, referred to as “primers”: [0000] GA231 (F3) 5' GCATCTTTATTATGGCAGAGAG 3' (Seq Id No. 16) GA232 (B3) 5' TGCTCTGAGAAAGGCATTA 3' (Seq Id No. 17) GA233 (FIP) 5' GCTGCTTCAAAGAAAGACTAAGGAAATGGACAACAGTCAAACAAC 3' (Seq Id No. 18) GA234 (BIP) 5'GCTTTCTCACAAGCATTTGGTTTTAAATTAGCCTGTAGTTTTACTTACTCTC 3' (Seq Id No. 19) GA236 (LB) 5' GTCTCCACTGGAGTATGT T TCTGTGGAGAC 3' (Seq Id No. 22) [0145] The underlined base corresponds to the mutated nucleotide at position 1849 of the JAK2 gene. [0146] PNA: Eurogentec, referred to as “PNA” GM43 NH2 GAGTATGT G TCTGTGGA CONH2 [0147] The underlined base corresponds to the wild type nucleotide at position 1849 of the JAK2 gene. [0148] Reaction buffer: 100 mM Tris HCl pH 8.8, 50 mM KCl, 40 mM MgSO4, 50 mM (NH4)2SO4, 0.5% Tween, “buffer 5×” [0149] dNTPs mix 25 mM (Fermentas), “dNTPs” [0150] Bst Large Fragment polymerase 8 U/μl (New England Biolabs), “Polymerase” [0151] Sterile apyrogen water (SALF Spa), “ddw” [0152] Procedure [0153] Sample Preparation [0154] Stock the primers in aliquots. It is better to store stock solutions at −20° C., while working dilutions should be stored at 4° C. [0155] Prepare reaction mix as follows: 0.2 μM outer primers (F 3 and B 3 ), 1.6 μM inner primers (FIP and BIP), 0.8 uM self-annealed loop primer specific for mutant JAK2 (LB), 0.8 uM PNA, 1× buffer solution, 1.4 mM dNTPs mix, 8 U Bst Polymerase. Final volume of the reaction mix must be 4/5 of the total reaction volume (i.e. 20 μl reaction mix+5 μl sample). Always keep reagents on ice. Prepare the mix for at least 23 samples, comprising 3 negative controls (100% wild type plasmid, 7e4 cps/μl), 18 positive control (3 samples 100% mutant plasmid, 3 samples 1% mutant plasmid diluted in wt plasmid, 3 samples 0.5% mutant plasmid diluted in wt plasmid, 3 samples 0.1% mutant plasmid diluted in wt plasmid, 3 samples 0.05% mutant plasmid diluted in wt plasmid, 3 samples 0.01% mutant plasmid diluted in wt plasmid (total amount of DNA 7e4 cps/μl), and one no target control. [0000] TABLE 4 sample mix composition Sample tube 1-3 4-6 7-9 10-12 13-15 16-19 Target to be Wt Mut Mut Mut Mut Mut add (5 μl) plasmid plasmid plasmid plasmid plasmid plasmid 7e4 cps/ 7e4 cps/ 7e3 cps/ 7e2 cps/ 7e1 cps/ 7e0 cps/ μl μl μl μl μl μl GA231 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA232 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA233 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 GA234 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 PNA 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 GA236 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 Buffer 2.5 2.5 2.5 2.5 2.5 2.5 LAMP 10x Bst Polymerase 1 1 1 1 1 1 8 U/μl dNTPs 25 mM 1.4 1.4 1.4 1.4 1.4 1.4 Ddw to 20 μl 13.8 13.8 13.8 13.8 13.8 13.8 [0156] Dispense 20 μl of reaction mix in the strip. Keep the strips on ice. Always keep the reaction mix on ice from now on. [0157] Prepare serial dilutions of the target (“target dilutions”) from shipped solution (wt plasmid and mut plasmid). Shipped solution is a 710 10 copies/μl. Dilute initially the mutant plasmid to a 710 4 copies/μl in Tris 10 mM, then dilute serially the mutant plasmid in wt plasmid to obtain the following concentrations of mutant sequences in wild type background: 1%, 0.5%, 0.1%, 0.05%, 0.01% (total amount per tube, 7e4 cps/ul). [0158] Add 5 μl of target dilutions to the strips, in triplicate. Add 5 ul of the target dilutions starting from the less concentrated one to the most concentrated one. Close all the tubes. [0159] Reaction [0160] The reaction follows the method scheme of FIG. 5 . [0161] Program the turbidimeter (Teramecs) for incubation at constant temperature and real time monitoring of turbidity in order to obtain a constant reaction temperature of 65° C. for 1 hour. [0162] Put the strips in the instrument immediately before the beginning of the programs. Start the program. [0163] Data Analysis [0164] Analyze the variation of absorbance in terms of a.u. to find the threshold time for each sample analyzed. The threshold time is the minute at which the sample absorbance, after baseline subtraction, reaches the arbitrary unit value representing the threshold (in this case 0.1 a.u.). The threshold time reached by each samples is correlated with its Log of DNA copies/μl. [0165] Results [0166] This approach consists of a selective mutant amplification based on a particular loop primer design resulting in selective hybridization of such loop primer to the dumb-bell formed from the mutant sequence ( FIG. 5 ). We designed a universal (mutant insensitive) set of primers comprising F 3 , B 3 , FIP and BIP to obtain a dumb-bell presenting the putative mutated nucleotide in the loop region comprised between B 1 and B 2 . Other experiments were performed presenting the putative mutated nucleotide in the loop region into B 2 or comprised between B 2 and B 1 c , with no relevant differences. We included in the primer set a particular loop primer presenting a 8-bases sequence region at its 5 ′ end complementary to its own sequence in 3 ′ end. Consequently, this special loop primer forms an intra-molecular hairpin structure in equilibrium with its open form at the reaction temperature (65° C.). [0167] When the mutated JAK2 sequence is present, this modified loop primer breaks its internal structure to anneal to the target, thanks to the thermodynamic equilibrium (Tm between primer and specific target=65° C.). The loop primer annealed to the specific mutated target is consequently extensible by the polymerase: the amplification can proceed. [0168] When the wt sequence is present in the sample, the same loop primer (specific for the MUT JAK2 gene) presents a Tm with aspecific target (59° C.) lower than the intra-molecular hairpin structure (65° C.). This results in auto-sequestration of the modified loop primer that prefers to fold in the hairpin structure rather than to form a duplex with aspecific target, since the intramolecular forces are higher than the intermolecular ones. To further increase the discrimination capability of the LAMP system based on selective self-annealed loop primer, we added to the reaction mix a Peptide Nucleic Acid (PNA). PNAs are non-extensible and not-displaceable oligonucleotides where the ribose-phosphate backbone is replaced by (2-aminoethyl)-glycine units linked by amide bonds. Each base pairing DNA/PNA contributes to the stability of the duplex structure more than a regular base pairing DNA/DNA. Therefore a single mismatch in a PNA/DNA duplex results in a significant difference in Tm. A PNA probe fully complementary to the WT sequence of the JAK2 gene prevents annealing and extension of the mutant self-annealed primer, suppressing amplification. In presence of a single mismatch, PNA does not inhibit loop primer hybridization, which leads to amplification. Therefore PNA can be used to selectively block the Wt sequence present in the sample. [0169] The PNA is designed to be complementary to the loop region comprised between B 2 and B 1 c presenting the WT nucleotide. It forms a stable duplex only with the wt complementary sequence (Tm 65.7° C.), preventing the annealing and extension of the mut-self-annealed loop primer and therefore suppressing the amplification. It does not anneal to the mut JAK2 sequence thanks to the lower affinity (Tm=56° C.). [0170] The PNA principle has been tested performing the reaction on 7 e3 cps/ul wild type plasmid and on 7 e3 cps/ul mutant plasmid, in parallel in absence and presence of the PNA “wt blocker” probe ( FIG. 9 ). In absence of PNA the WT plasmid is aspecifically amplified by the self-annealed mutant loop primer, with a delay of 5 min in respect to the specific mutated target. In presence of PNA, the WT plasmid is not amplified within one hour reaction by the self-annealed mutant loop primer. The amplification of the mutant plasmid is delayed of about 5 minutes. The PNA forms a stable duplex only with the wt complementary sequence preventing the annealing and extension of the mut-self-annealed loop primer and therefore suppressing the amplification within 1 hour of reaction. [0171] The selectivity of this assay has been evaluated, performing the reaction on serial dilutions of mutant plasmid in wild type background ( FIG. 10 ). The selectivity achieved is less than 0.01% (35 copies tot mutant plasmid in 34965 copies of wt plasmid). This approach has higher selectivity than the assays described in prior art, about 3 Logs more in respect to direct sequencing, RFLP and pyrosequencing and about 2 Logs in respect to ARMS, Real-time techniques and DNA-melting curve analysis. As to LAMP dumb-bell method, it is intrinsically not useful to detect single point mutations in a high background of wild type sequences. [0172] The WT sample (35000 cps wt plasmid) is not amplified in one hour reaction. The specific mutant target is detected down to 0.01% mutant sequences in wt (35 copies tot mutant plasmid in 34965 copies of wt plasmid). This approach has a higher selectivity than the assays described in literature (about 2 Logs). The assay is linear down to 0.1% MUT (350 copies tot mutant plasmid in 34650 copies of wt plasmid). It allows detection and quantification of low percentage of mutant sequences in large amount of wt. It represents a further improvement in respect of the other strategies described in this report and in respect to the methods described in literature. EXAMPLE 5 LAMP “Self-Annealed Loop Primer with PNA” on Clinical Samples: Comparison with ARMs [0173] 29 samples of DNA extracted from patients at Ospedali Riuniti di Bergamo were analyzed using JAK2 LAMP “self-annealed loop primer with PNA” strategy, as described in the EXAMPLE 4. The results obtained have been compared with the ones obtained at the hospital using the ARMs technology. The ARMS exploits the fact that oligonucleotide primers must be perfectly annealed at their 3 ′ ends for a DNA polymerase to extend these primers during PCR. By designing oligonucleotide primers that match only the specific JAK2 point mutation ARMS can distinguish between wild type and mutant alleles. [0174] As shown in Table 5, all the samples diagnosed as positive by ARMS have been detected as positive by LAMP. Out of 15 samples resulted negative by ARMS, 11 have been diagnosed as negative by LAMP and 4 as low positive. To exclude that the 4 discordant samples resulted mutated by LAMP were false positive and to confirm that the mutation diagnosis was due to an higher selectivity of the modified-LAMP method, we tested the samples using a third assay. The assay consists in PCR amplification of the JAK2 region of interest in presence of the PNA molecule complementary to the wild type target. The purpose is to enrich the mutated base, if present, by suppression of the wild type via PNA clamping. If the mutated region is enriched to a level of 20% of the sample, it can be detected by the direct-sequencing. The primers (GA231 forward and GA232 reverse) and the PNA are the same described above (paragraph “Example 4”). The amplification was performed in presence of 1× reaction buffer, 2.5 mM MgCl 2 , 200 μM dNTPs, 500 nM forward and reverse primers, 1.5M PNA and 0.025 U Taq Gold in a final volume of 45 μl. 5 μl of target 20 ng/μl was added to the reaction mix. The resulting solution was incubated in a thermocycler, following a thermal program consisting in 10 min at 95° C. followed by 35 cycles of 30 sec at 94° C., 40 sec at 62° C. cycles, 30 sec at 58° C. and 30 sec at 72° C. and finishing with 10 min at 72° C. for the final extension. The four discordant clinical samples, one no-target control sample and a positive and negative plasmid target were tested in duplicate. The resulting amplification products were separated on an agarose gel containing EtBr to visualize the amplification bands. The no-target control was not amplified. The negative control containing the wild type plasmid was slightly amplified, and a weak band was visible on the agarose gel. The positive control containing the mutated plasmid was strongly amplified presenting a strong band on the agarose gel. The clinical samples were amplified. The amplification products were consequently analyzed via automatic-sequencing. All the discordant clinical samples show a double peak in position 1849, corresponding to the Guanine (wild type) base and the Thymine (mutated) base. This result confirm that the four discordant samples have been correctly diagnosed mutated by LAMP, while they results false negative by ARMS. [0000] TABLE 5 LAMP self-annealed sample ARMs loop primer with PNA PIGI − + (low) PEVI − − ACGI + + BEMA + + BILU + + PAAN − + (low) BOMA − − OLIN − − PALO + + BOED + + SAGE + + BAGI + + FEGI + + BEAL + + TALU + + CAPI + + SAGI + + SAVGI + + PECA + + SCLU − − BILU2 − + (low) NAGI − − MAST − − COSA − − GUAL − − COCL − − PEMG − − SABA − + (low) ANPI − − EXAMPLE 6 Fluorescent JAK2-Modified-LAMP “Self-Annealing Loop Primer Strategy” [0175] Reagents [0176] JAK2 plasmids were synthesized by the supplier GeneArt (Regensburg, Germany) to contain the wild type or the mutant JAK2 sequence. In details: which Insert corresponds to the sequence 1689-1722 of MN — 004972, including a G base at nucleotide1849, referred to as “wt plasmid” which Insert corresponds to the sequence 1689-1722 of MN — 004972 cloned, including a T base at nucleotide1849, referred to as “mut plasmid” [0179] Primers: synthesized by Eurofins MWG Operon, referred to as “primers”: GA231 (F 3 ) 5 ′ GCATCTTTATTATGGCAGAGAG 3 ′ (Seq Id No. 16) GA232 (B 3 ) 5 ′ TGCTCTGAGAAAGGCATTA 3 ′ (Seq Id No. 17) GA233 (FIP) 5 ′ GCTGCTTCAAAGAAAGACTAAGGAAATGGACAACAGTCAAACAAC 3 ′ (Seq Id No. 18) GA234 (BIP) 5 ′GCTTTCTCACAAGCATTTGGTTTTAAATTAGCCTGTAGTTTTACTTACTCTC 3 ′ (Seq Id No. 19) GA236 (LB) 5 ′TAMRA-TGTCTCCACTGGAGTATGTTTCTGTGGAGAC 3 ′ (Seq Id No. 21). The underlined base corresponds to the mutated nucleotide at position 1849 of the JAK2 gene. The bold Tymine base at 5 ′ end is not complementary to the target sequence. It has been added to separe the fluorophore from the Guanine base downstream, which has a quenching effect. GA235 (LF) 5 ′- 5 ′GTCTCCACTGGAGTATGTGTCTGTGGAGAddC 3 ′(Seq Id No. 20) the underlined base is the wild type nucleotide in position 1849 of the JAK2 gene. ddC stands for not-extensible dideoxy-citosine. [0185] Reaction buffer: 100 mM Tris HCI pH 8.8, 50 mM KCl, 40 mM MgSO4, 50 mM (NH4)2SO4, 0.5% Tween, “buffer 5×” [0186] dNTPs mix 25 mM (Fermentas), “dNTPs” [0187] Bst Large Fragment polymerase 8 U/μl (New England Biolabs), “Polymerase” [0188] Sterile apyrogen water (SALF Spa), “ddw” [0189] Procedure [0190] Sample Preparation [0191] Stock the primers in aliquots. It is better to store stock solutions at −20° C., while working dilutions should be stored at 4° C. [0192] Prepare reaction mix as follows: 0.2 μM outer primers (F 3 and B 3 ), 1.6 μM inner primers (FIP and BIP), 0.8 μM fluorescent self-annealed loop primer specific for mutant JAK2 (LB), 0.8 μM self annealed not-extensible loop primer for wild type JAK2 (LF), 1× buffer solution, 1.4 mM dNTPs mix, 8 U Bst Polymerase. Final volume of the reaction mix must be 4/5 of the total reaction volume (i.e. 20 μl reaction mix+5 μl sample). Always keep reagents on ice. Prepare the mix for at least 23 samples, comprising 3 negative controls (100% wild type plasmid, 7e3 cps/μl), 18 positive control (3 samples 100% mutant plasmid, 3 samples 1% mutant plasmid diluted in wt plasmid, 3 samples 0.5% mutant plasmid diluted in wt plasmid, 3 samples 0.1% mutant plasmid diluted in wt plasmid, 3 samples 0.05% mutant plasmid diluted in wt plasmid, 3 samples 0.01% mutant plasmid diluted in wt plasmid (total amount of DNA 7e3 cps/μl), and one no target control. [0000] TABLE 6 sample mix composition Sample tube 1-3 4-6 7-9 10-12 13-15 16-19 Target to be Wt Mut Mut Mut Mut add (5 μl) plasmid plasmid plasmid plasmid plasmid 7e3 cps/ 7e3 cps/ 7e2 cps/ 7e1 cps/ 7e0 cps/ μl μl μl μl μl GA231 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA232 100 μM 0.05 0.05 0.05 0.05 0.05 0.05 GA233 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 GA234 100 μM 0.4 0.4 0.4 0.4 0.4 0.4 GA235 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 GA236 100 μM 0.2 0.2 0.2 0.2 0.2 0.2 Buffer 2.5 2.5 2.5 2.5 2.5 2.5 LAMP 10x Bst Polymerase 1 1 1 1 1 1 8 U/μl dNTPs 25 mM 1.4 1.4 1.4 1.4 1.4 1.4 Ddw to 20 μl 13.8 13.8 13.8 13.8 13.8 13.8 [0193] Dispense 20 μl of reaction mix in the strip. Keep the strips on ice. Always keep the reaction mix on ice from now on. [0194] Prepare serial dilutions of the target (“target dilutions”) from shipped solution (wt plasmid and mut plasmid). Shipped solution is a 710 10 copies/μl. Dilute initially the mutant plasmid to a 710 4 copies/μl in Tris 10 mM, then dilute serially the mutant plasmid in wt plasmid to obtain the following concentrations of mutant sequences in wild type background: 1%, 0.5%, 0.1%, 0.05%, 0.01% (total amount per tube, 7e3 cps/ul. [0195] Add 5 μl of target dilutions to the strips, in triplicate. Add 5 μl of the target dilutions starting from the less concentrated one to the most concentrated one. Close all the tubes. [0196] Reaction [0197] The reaction follows the method scheme of FIG. 4 . [0198] Program the real time instrument for incubation at constant temperature in order to obtain a constant reaction temperature of 65° C. for 1 hour. Program the real time instrument in order to obtain a fluorescence reading per minute. [0199] Put the strips in the instrument immediately before the beginning of the programs. Start the program. [0200] Data Analysis [0201] The fluorescent self-annealed loop primer in reaction produces a fluorescent signal once it is excited by an appropriated wavelenght-light emission. When the LAMP reaction proceeds, the fluorescent self-annealed loop primer is incorporated in the amplification products, being consequently annealed to a complementary nucleotide sequence. The fluorescent self-annealed loop primer is designed to be complementary to a sequence containing at least one Guanine nucleotide close to its 5′ end. The Guanine base can absorbe the wavelengh emitted by the fluorophore (TAMRA in our case), causing a fluorescent signal quenching. The LAMP reaction can be consequently detected by analysis of the variation of fluorescence in terms of signal quenching, to find the threshold time relative to each analyzed sample. The threshold time is the minute at which the fluorescence signal in reaction reaches 50% of quenching. The threshold time reached by each samples is correlated with its Log of DNA copies/μl. [0202] Results [0203] This approach consists of a selective mutant amplification based on a particular loop primer design resulting in selective hybridization of such loop primer to the dumb-bell formed from the mutant sequence ( FIG. 4 ). We designed a universal (mutant insensitive) set of primers comprising F 3 , B 3 , FIP and BIP to obtain a dumb-bell presenting the putative mutated nucleotide in the loop region comprised between B 1 and B 2 . Other experiments were performed presenting the putative mutated nucleotide in the loop region into B 2 or comprised between B 2 and B 1 c , with no relevant differences. We included in the primer set a particular loop primer presenting a 8-bases sequence region at its 5 ′ end complementary to its own sequence in 3 ′ end. [0204] Consequently, this special loop primer forms an intra-molecular hairpin structure in equilibrium with its open form at the reaction temperature (65° C.). [0205] When the mutated JAK2 sequence is present, this modified loop primer breaks its internal structure to anneal to the target, thanks to the thermodynamic equilibrium (Tm between primer and specific target=65° C.). The loop primer annealed to the specific mutated target is consequently extensible by the polymerase: the amplification can proceed. [0206] When the wt sequence is present in the sample, the same loop primer (specific for the MUT JAK2 gene) presents a Tm with aspecific target (59° C.) lower than the intra-molecular hairpin structure (65° C.). This results in auto-sequestration of the modified loop primer that prefers to fold in the hairpin structure rather than to form a duplex with aspecific target, since the intramolecular forces are higher than the intermolecular ones. To limit the competition of the loop primer previously described for the wild type sequences likely to be present in large excess in the clinical sample, we added another modified loop primer characterized by a structure similar to the one previously described, but whit a sequence complementary to the JAK2 wild type sequence (with G base at position 1489). [0207] The 3 ′ end of this “competitor” loop primer is made not extensible by a modification ( 3 ′ dideoxy). The task of this competitor is to “silence” the wt and allow the specific mutant primer to find its target. [0208] When the “competitor” recognizes the specific wild type sequence, it breaks its intramolecular structure to anneal to the WT target, thanks to a higher affinity (Tm duplex wt target-wt modified loop primer=67° C.); The loop primer annealed to the wt target is not extensible, resulting in no amplification of the wt sequences. Since the reaction is conducted at constant temperature, the wt-loop primer will remain annealed to the wt sequences preventing aspecific annealing of the MUT loop primer. [0209] Differently, the “competitor” presents a Tm with its aspecific (mutant) target (62° C.) lower than the intra-molecular hairpin structure that it forms with itself (65° C.). This results in auto-sequestration of the modified loop primer that prefers to fold in the hairpin structure rather than to form a duplex with the aspecific target, since the intramolecular forces are higher than the intermolecular ones. [0210] To follow the reaction on a real-time instrument, we labeled the 5 ′ end of the mutant modified loop primer with a FAM dye. To avoid the binding of the fluorophore to the guanine base present at the 5 ′ end of the modified loop primer, which has a quenching effect, we added a Thymine base to the extremity of the probe. The modified-labeled primer, when present in solution, emits a fluorescent signal if excited by an appropriate-wavelength light. When the LAMP reaction starts and proceeds, the fluorescent self-annealed loop primer is incorporated in the amplification products, being consequently annealed to a complementary nucleotide sequence, containing several Guanine residues. The Guanine bases can absorb the wavelength emitted by the fluorophore, causing a fluorescent signal quenching visible in real time. The LAMP reaction can be consequently monitored throughout the analysis of the decreasing of fluorescence signal due to the “quenching effect” determined by LAMP product generation. REFERENCES [0211] 1. Levine, R. L. et al. Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Cancer Cell 7,387-397 (2005). [0212] 2. James, C. et al. A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera. Nature 434,1144-1148 (2005). [0213] 3. Baxter, E. J. et al. Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 365,1054-1061 (2005). [0214] 4. Kralovics, R. et al. A gain of function mutation of JAK2 in myeloproliferative disorders. N. Engl. J. Med. 352,1779-1790 (2005). [0215] 5. Nelson M E, Steensma D P: JAK2 V617F in myeloid disorders: what do we know now, and where are we headed? Leuk Lymphoma 2006, 47:177-194 [0216] 6. James C, Ugo V, Le Couedic J-P, Staerk J, Delhommeau F, Lacout C, Garcon L, Raslova H, Berger R, Bennaceur-Griscelli A, Villeval J L, Constantinescu S N, Casadevall N, Vainchenker W: A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera. Nature 2005, 434:1144-1148 [0217] 7. De Keersmaecker K, Cools J: Chronic myeloproliferative disorders: a tyrosine kinase tale. Leukemia 2005, 20:200-205 [0218] 8. Kaushansky K: On the molecular origins of the chronic myeloproliferative disorders: it all makes sense. Blood 2005, 105:4187-4190 [0219] 9. Baxter E J, Scott L M, Campbell P J, East C, Fourouclas N, Swanton S, Vassiliou G S, Bench A J, Boyd E M, Curtin N, Scott M A, Erber W N, Green A R: Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. The Lancet 2005, 365:1054-1061 [0220] 10. Smith T A, Whelan J, Parry P J: Detection of single-base mutations in a mixed population of cells: a comparison of SSCP and direct sequencing. Genet Anal Tech Appl 1992,9:143-145 [0221] 11. James C, Delhommeau F, Marzac C, Teyssandier I, Couedic JP, Giraudier S, Roy L, Saulnier P, Lacroix L, Maury S, Tulliez M, Vainchenker W, Ugo V, Casadevall N: Detection of JAK2 V617F as a irst intention diagnostic test for erythrocytosis. Leukemia 2006, 20:350-353 [0222] 12. Newton C R, Graham A, Heptinstall L E, Powell S J, Summers C, Kalsheker N, Smith J C, Markham A F: Analysis of any point mutation in DNA: the amplification refractory mutation system (ARMS). Nucleic Acids Res 1989, 17:2503-2516 [0223] 13. Jones A V, Kreil S, Zoi K, Waghorn K, Curtis C, Zhang L, Score J, Seear R, Chase A J, Grand F H, White H, Zoi C, Loukopoulos D, Terpos E, Vervessou EC, Schultheis B, Emig M, Ernst T, Lengfelder E, Hehlmann R, Hochhaus A, Oscier D, Silver R T, Reiter A, Cross N C: Widespread occurrence of the JAK2 V617F mutation in chronic myeloproliferative disorders. Blood 2005, 106:2162-2168 [0224] 14. James C, Delhommeau F, Marzac C, Teyssandier I, Couedic JP, Giraudier S, Roy L, Saulnier P, Lacroix L, Maury S, Tulliez M, Vainchenker W, Ugo V, Casadevall N: Detection of JAK2 V617F as a first intention diagnostic test for erythrocytosis. Leukemia 2006, 20:350-353 [0225] 15. Baxter E J, Scott L M, Campbell P J, East C, Fourouclas N, Swanton S, Vassiliou G S, Bench A J, Boyd E M, Curtin N, Scott M A, Erber W N, Green AR: Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. The Lancet 2005, 365:1054-1061 [0226] 16. Antonioli E, Guglielmelli P, Pancrazzi A, Bogani C, Verrucci M, Ponziani V, Longo G, Bosi A, Vannucchi AM: Clinical implications of the JAK2 V617F mutation in essential thrombocythemia. Leukemia 2005, 19:1847-1849 [0227] 17. Jelinek J, Oki Y, Gharibyan V, Bueso-Ramos C, Prchal J T, Verstovsek S, Beran M, Estey E, Kantarjian H M, Issa J P: JAK2 mutation 1849G_T is rare in acute leukemias but can be found in CMML, Philadelphia chromosome-negative CML, and megakaryocytic leukemia. Blood 2005, 106:3370-3373 [0228] 18. Jones A V: Widespread occurence of the JAK2 V617F mutation in chronic myeloproliferative disorders. Blood 2005, 106: 2162-2168. [0229] 19. Steensma D: JAK2 V617F in myeloid disorders: molecular diagnostic techniques and their clinical utility. Journal of Molecular Diagnostics 2006, 8:397-411. [0230] 20. Iwasaki M. et al. Genome Letters 2003, 2:119-126. [0231] 21. Fukuta S. et al. J Appl Genet 2006, 47:303-308. [0232] 22. Ikeda S. et al. Pathol. Intern. 2007, 57: 594-599.	The present invention refers to a method for detecting a point mutations of a nucleotide sequence by an improve- ment of the LAMP (loop amplification mediated polymerization) amplification method, as well as to a set of primers and kit there- for. As a non limitative embodiment, the invention refers to the G1849T mutation of the JAK2 gene.	2
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. Section 119 of German Application No. 102005059406.9 filed Dec. 13, 2005 and International Application No. PCT/EP2006/011601 filed Dec. 4, 2006, the contents of which are incorporated by reference herein in their entireties. FIELD OF THE INVENTION This invention relates to an extrusion process for the production of emulsifier-containing starting products for foods. BACKGROUND OF THE INVENTION In the production of foods nowadays, mixtures of food additives are often used and are incorporated—generally as semifinished products—in another mixture of ingredients and then further processed. Corresponding compositions make the work involved easier and lead to greater safety of production because the need for weighing and mixing is eliminated. The production of these preliminary products often results in mixtures which, despite the same chemical composition, behave very differently during further processing, depending on the process used for their production. Thus, not only the chemical composition and certain physicochemical properties, but also the production processes, have a major bearing on the properties of the final formulations in which these preliminary mixtures are used. European patent EP 0 153 870 B1 (Nexus) describes preparations in the form of free-flowing powders of a carrier with a lipophilic surface-active substance which are preferably used for the production of baking compositions. The lipophilic surface-active substance acquires far better wettability as a result of processing with a carrier. A composition normally produced by spray drying was thus produced for the first time by a more economical and simpler extrusion process and was distinguished by improved behavior of the baking doughs subsequently produced. In a so-called whipping test, in which the dough is beaten and as much air as possible is intended to be stably incorporated in order to obtain a light, fluffy product after baking, the product according to the invention showed clear advantages over conventional products. Nevertheless, there is a need to improve the properties of emulsifier-containing ingredients for the production of foods and particularly confectionery. The production process ought to be able to be carried out in a simple manner. The extruded surface-active substances desirably exhibit improved properties in regard to their foaming capacity and stability which would be reflected in the end products obtained. BRIEF SUMMARY OF THE INVENTION The present invention is directed to a process for the production of extruded compositions suitable for use in a food product, in which a carrier is hydrophilicized by addition of a hydrophilic agent, and a surface-active compound is subsequently added in another step to the hydrophilicized carrier to form compositions which are then extruded. The present invention is further directed to a process for the extrusion of a composition from an extruder containing at least one surface-active compound and at least one hydrophilicized carrier, which process comprises: a) providing a carrier which is suitable for use in a food product; b) hydrophilicizing the carrier by adding a hydrophilicizing agent to form a hydrophilicized carrier; c) adding a surface-active compound to form a composition which comprises the hydrophilicized carrier and the surface-active compound; and d) extruding the composition; wherein the surface-active compound is added after the hydrophilicized carrier is formed. This can be achieved by way of two different embodiments of the process of the invention. Either the carrier can be mixed with the hydrophilic agent before the beginning of extrusion and the resulting mixture fed to the extruder (for example as shown in FIG. 1 ) or hydrophilic agents are added to the carrier in the extruder and the surface-active compounds to be extruded are added afterwards as the extrusion process continues (for example as shown in FIG. 2 ). In a preferred embodiment, there is no intensive contact between the hydrophilic agents and the surface-active compounds, and the hydrophilic agents are added for hydrophilicizing the carrier before more surface-active compound is added. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates one embodiment of the extrusion process. Here, in the process according to the invention, the carrier added to segment 1 can already be hydrophilicized by mixing with a hydrophilicizing agent prior to addition to the extruder. FIG. 2 illustrates another embodiment of the extrusion process. Here, the carrier is hydrophilicized by addition to segment 3 of the extruder containing a hydrophilicizing agent. It has surprisingly been found that the extruded compositions obtainable by the process according to the invention not only show very good stability in storage, wettability and flow properties, they also have improved applicational properties, such as foaming capacity and stability in paste form, in relation to comparable commercially available powder-form products. The preliminary hydrophilicization leads to a modified structure or to a modified incorporation of the surface-active substances and hence to improved availability of the surface-active compound. This favorably influences the foaming process during production of the paste and desirably results in confectionery items with a loose and more stable structure. Although the process may comprise another step, this does not complicate production and, in the second embodiment, the process can still be carried out as a “one-pot process”. The results obtained in trials demonstrated that the extrusion process produced very constant results with respect to the properties of the extruded compositions. DETAILED DESCRIPTION OF THE INVENTION Carriers The carriers according to the invention suitable for the extrudate of surface-active substances are the typical components or fillers used in the food industry. These generally include such substances as the flours or starches used in the production of confectionery (for example wheat starch, corn starch, rice starch, potato starch), modified starches, cellulose or cellulose derivatives and other carbohydrates, such as for example, sucrose, glucose, fructose, lactose, dextrins, maltodextrins, sugar alcohols, and malt-derived substances (for example malt flours, malt extracts), yeast food, soya products, such as soya flours, soya proteins, thickeners and hydrocolloids (including guar gum, cereal flour, carob gum, xanthan, alginate), milk products, such as skimmed milk powder, whole milk powder, whey powder, caseins, and mixtures thereof, this description being by no means complete, or limiting of the scope of carriers suitable for use in the invention. Starches and flours are preferably used for the production of confectionery. Hydrophilicizing Agents Suitable emulsifiers which may be used as hydrophilicizing agents for the carrier may be used in amounts of from about 0.03 to 10% by weight, and preferably in amounts of from about 0.1 to 5% by weight, based on the weight of the extrudate. Basically, the hydrophilicizing agent may have an HLB value above 8 and preferably above 12. The emulsifiers may include in particular: (a) sorbitan esters; (b) polysorbates, i.e. products of the addition of 1 to 20 mol ethylene oxide onto sorbitan mono-, sesqui-, di- and/or triesters based on fatty acids containing 6 to 22, and preferably 12 to 18 carbon atoms, such as for example addition products of 5 to 15 mol ethylene oxide onto sorbitan monolaurate, sorbitan dipalmitate, sorbitan tristearate, sorbitan monooleate and the like; (c) sugar esters, such as sucrose esters, for example sucrose monopalmitate and stearate; (d) fatty acids and salts thereof; and (e) partial esters of glycerol with edible fatty acids condensed with about 1 to 40 mol ethylene oxide. Surface-Active Compounds The surface-active compounds processed to extrudates for the production of foods are different from the hydrophilicizing agent (hydrophilic emulsifier) and, preferably, have lower HLB values. Surface-active compounds typically used in food production may include in particular (individually or in combination): (a) polyol esters; (b) polyhydrols; (c) mono- and diglycerides and technical mixtures thereof based on fatty acids containing 6 to 22, and preferably 12 to 18 carbon atoms, such as for example lauric acid monoglyceride, palmitic acid monoglyceride, stearic acid monoglyceride or oleic acid monoglyceride; (d) lecithins; (e) propylene glycol esters; and (f) esterified monoglycerides (acetems, lactams). Extrusion Process In an extruder, dry or paste-form materials are transported forwards by a rotating screw and, in the process, are mixed, size-reduced, compressed and plasticized, and extruded through an end piece. The more or less dry starting materials are delivered via gravimetric or volumetric dosing units to the main part of the extruder. In this part of the extruder, one or two screws rotate in a hollow cylinder. The dosing/charging of the compactor can be influenced through the rotational speed of the screw(s). Depending on the shearing energy applied, the screw mixes and heats the substances relatively intensively or non-intensively (through mechanical shearing and friction). A pumpable paste is thus formed and is forced through a nozzle and finely atomized. The extrusion process is carried out at a nozzle temperature of from about 50 to 150° C., and preferably about 130° C. The advantages of the invention are achieved by way of the addition of the hydrophilicizing agent to the carrier materials before addition of the surface-active substances. This can be done in a separate, preceding process step or may be integrated into the extrusion process. In either case, hydrophilicization of the carrier is conducted prior to the addition of the surface-active substances. The following examples are illustrative of the invention and should not be construed as limiting of the scope of the invention. EXAMPLES Extrusion Process Extruder: Werner & Pfleiderer ZSK 40 twin-screw extruder, Brabender gravimetric dosing system. TABLE 1 Screw Configuration for W&P ZSK 40 Element Helix angle/ Length length [mm] Task [mm] 25/25 Filling 25 25/25 50 40/10 60 Starch Disk/1 61 Starch 60/60 121 Starch 60/60 181 Starch 988/30 211 Starch 40/40 251 Starch 40/40 291 Starch 40/40 331 Starch 40/40 371 Starch 40/20 Filling 391 Starch + water/solution 40/40 431 Starch + water/solution KB 45/5/40 Mixing 471 Starch + water/solution 40/40 511 Starch + water/solution KB 45/5/20 531 Starch + water/solution 40/40 Trans- 571 Starch + water/solution Disk/1 port 572 Starch + water/solution Disk/1 573 Starch + water/solution 60/60 Filling 633 Starch + water/solution + emulsifier Disk/1 Trans- 634 Starch + water/solution + emulsifier 40/40 port 674 Starch + water/solution + emulsifier 40/10 684 Starch + water/solution + emulsifier KB 45/5/20 Mixing, 704 Starch + water/solution + emulsifier KB 45/5/20 trans- 724 Starch + water/solution + emulsifier 40/40 port 764 Starch + water/solution + emulsifier 40/10 774 Starch + water/solution + emulsifier 40/10 784 Starch + water/solution + emulsifier KB 45/5/40 824 Starch + water/solution + emulsifier 40/10 834 Starch + water/solution + emulsifier 40/10 844 Starch + water/solution + emulsifier 40/20 864 Starch + water/solution + emulsifier 40/10 874 Starch + water/solution + emulsifier 40/10 884 Starch + water/solution + emulsifier KB 90/5/40 Mixing 924 Starch + water/solution + emulsifier 40/40 Trans- 964 Starch + water/solution + emulsifier 40/40 port 1004 Starch + water/solution + emulsifier 40/40 and 1044 Starch + water/solution + emulsifier 25/25 compres- 1069 Starch + water/solution + emulsifier 25/25 sion 1094 Starch + water/solution + emulsifier 40/10 1104 Starch + water/solution + emulsifier 40/10 1114 Starch + water/solution + emulsifier E 40/80 1194 Starch + water/solution + emulsifier Powder dosage: 21 kg/h segment 1 Surface-active substances: mixture of a polyglycerol ester of fatty acids (FDA-CFR-No. 172.854, EEC No. 475; Polymuls) and mono- and diglycerides of edible fatty acids (EEC No. E 471: Monomuls 90-35) Dosage: 8.9 kg/h in segment 4 Water dosage: 0.9 kg/h (+0.4 kg/h hydrophilic additives) in segment 3 Die plate: 4×1 mm Screw speed: 200 r.p.m Temperatures: segment 1: room temperature segments 2-7: 80° C. segment 8: 130° C. Example 1 A native starch (Remy D R, Remy Industries, Belgium) was mixed with 5% by weight of a powder-form hydrophilic emulsifier (potassium stearate, LIGA Kaliumstearat V pflanziich, Peter Greven Fett-Chemie GmbH & Co. KG, Germany) and the resulting mixture was used in the above-described extrusion process. For comparison, the process was carried out without addition of the hydrophilic powder-form emulsifier (corresponding to the process described by Nexus). Example 2 A mixture of hydrophilic emulsifiers of 50% TWEEN 20 and 50% TWEEN 80 were 31.25% dissolved in water and added to the extrusion process between addition of the starch (corresponding to Example 1) and before addition of the surface-active substances. For comparison, the process was carried out without addition of the hydrophilic emulsifiers in the water phase (corresponding to the process described by Nexus). Whipping Test: Composition of the dough: Wheat flour (type 405) 152 g (60%) Wheat starch 102 g (40%) Cane sugar 208 g (82%) 1 Baking powder (standard “Eisella”) 10 g (4%) 1 Extruded emulsifier 28 g (11%) 1 Egg 250 g (100%) 1 Water 100 g (40%) 1 1 based on flour, starch as 100% All ingredients were mixed at room temperature and whipped in a Hobart N50G for 2 mins. 45 secs. at level 3 and for 30 secs. at level 2; and in a Hobart A200 for 6 mins. at level 3 and for 30 secs. at level 2. The density of the paste obtained was determined. The values obtained are shown in the following: For Example 1 a) paste density with emulsifier based on native starch (Nexus process): 520 g/l; b) paste density with emulsifier based on native starch mixed with potassium stearate: 320 μl; and c) paste density with commercially available extruded emulsifier (Nexus), Emulpals 106, Batch No. 2909388: 384 g/l. For Example 2 a) paste density with emulsifier based on native starch (Nexus process): 520 g/l; b) paste density with emulsifier based on native starch and hydrophilic additives in water: 336 g/l; and c) paste density with commercially available extruded emulsifier (Nexus), Emulpals 106, Batch No. 2909388: 384 g/l. In Examples 1 and 2, the embodiments of the invention (b) demonstrated lower paste densities than those made by way of the prior art.	A process for the extrusion of a composition from an extruder, which composition is suitable for use in a food product, is disclosed. The process provides a composition which is comprised of a hydrophilicized carrier and surface-active compound which is extruded. The process describes adding the surface-active compound after the carrier is hydrophilicized.	0
RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Application No. 60/990,935, which was filed on Nov. 29, 2008. TECHNICAL FIELD [0002] This invention generally relates to a crossover valve for an air suspension. BACKGROUND OF THE INVENTION [0003] Air suspensions are often utilized in off-road vehicles; however, operational performance of these off-road vehicles can be limited by roll stiffness of the suspension. Roll stiffness limits an articulation angle of the suspension and keeps some vehicle tires from contacting the ground under certain off-road conditions. For example, uneven ground can cause one wheel to have ground contact while a laterally opposite wheel remains out of contact with the ground due to the limited articulation of the suspension. [0004] One solution has been to use a crossover valve in an axle to vary stiffness as needed between laterally opposed springs in an attempt to maintain four wheel contact with the ground. The crossover valve attenuates stiffness by allowing air from one spring on one side of the vehicle to be communicated to a laterally opposite spring on the other side of the vehicle. For a typical four-wheel drive vehicle, one crossover valve is used on a front axle to allow air communication between front right and front left springs, and another crossover valve is used on a rear axle to allow air communication between rear right and rear left springs. [0005] The inclusion of the two crossover valves is disadvantageous from a cost and material perspective. Further, due to limited packaging space, it is a challenge to route and plumb the crossover valves into the suspension. [0006] Thus, there is a need for a more cost effective suspension control that provides desired stiffness attenuation in addition to overcoming other deficiencies in the prior art as outlined above. SUMMARY OF THE INVENTION [0007] An air suspension system includes a crossover valve that is integrated into a suspension valve block. The suspension system has a plurality of springs including front and rear springs, and left and right springs. Each spring has an associated spring valve. The crossover valve, which is normally open, can separate left and right portions of the valve block. When the crossover valve is closed all associated spring valves can be opened to allow flow between right and left springs but not between front and rear springs. [0008] In one example, the air suspension includes a crossover valve in fluid communication with a manifold, a first set of springs in fluid communication with the manifold through a first set of valves, and a second set of springs in fluid communication with the manifold through a second set of valves. The crossover valve is movable between an open position to allow fluid communication to each of the first and the second sets of springs and a closed position that separates the first set of springs from the second set of springs. Fluid communication occurs only between springs in the first set of springs when the crossover valve is in the closed position, and fluid communication occurs only between springs in the second set of springs when the crossover valve is in the closed position. [0009] In one example, the first set of springs includes a front right spring and a front left spring for a front axle, and the first set of valves includes a front right valve controlling fluid communication between the manifold and the front right spring and a front left valve controlling fluid communication between the manifold and the front left spring. The second set of springs includes a rear right spring and a rear left spring for a rear axle, and the second set of valves includes a rear right valve controlling fluid communication between the manifold and the rear right spring and a rear left valve controlling fluid communication between the manifold and the rear left spring. [0010] In one example, the air suspension system includes a control, such as an electronic control unit, computer, microprocessor, etc., which generates control signals to open and close the valves. The crossover valve and the first and second sets of valves can only be moved between open and closed positions in response to a control signal generated by the control. [0011] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1A is top schematic view of a vehicle with an air suspension incorporating the subject invention. [0013] FIG. 1B is a front schematic view of a rear axle from FIG. 1A . [0014] FIG. 2 is a schematic diagram including a pressure manifold, crossover valve, springs, and spring valves. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0015] FIG. 1A shows a vehicle 10 that includes a front axle 12 and a rear axle 14 . An air suspension system 16 includes a reservoir 18 and a plurality of springs 20 a - d that are in fluid communication with the reservoir 18 . The springs 20 a - d are associated with the front 12 and rear 14 axles. Spring 20 a comprises a right front spring, spring 20 b comprises a left front spring, spring 20 c comprises a right rear spring, and spring 20 d comprises a left rear spring. The springs 20 a - d absorb road load inputs to provide a comfortable ride. Air pressure within the springs 20 a - d can be varied to improve handling when the vehicle 10 is used in an off-road application, for example. [0016] FIG. 1B shows a front view of the rear axle 14 and air suspension system 16 . The suspension system 16 would be similarly configured for the front axle 12 . The springs 20 a - d are typically positioned between a vehicle chassis or frame member 24 and a component that is either associated with the axles or which is another suspension component. In the example shown in FIG. 1B , the right and left rear springs 20 c , 20 d are supported by an axle housing 22 . However, it should be understood that while the springs are shown as being positioned directly between the associated axle and the frame member 24 , the springs could also be positioned between a suspension component, such as a control arm for example, which would be supported by the axle and the frame member. [0017] In the example of a four-wheel drive vehicle, the front 12 and rear 14 axles are drive axles that receive driving input from a power source 26 such as an engine or an electric motor for example. The front 12 and rear 14 axles each include gear assemblies 28 that drive axle shafts 30 to rotate a pair of laterally spaced wheels 32 . [0018] As discussed above, the springs 20 a - d are each filled with air and the pressure inside of the springs 20 a - d is varied to provide a desired ride and handling characteristic. As shown in FIG. 1A , the front right 20 a and front left 20 b springs are associated with the front axle 12 , and the rear right 20 c and rear left 20 d springs are associated with the rear axle 14 . [0019] The air suspension system 16 comprises a suspension valve block 40 , shown in detail in FIG. 2 , which controls air supply to the springs 20 a - d . The valve block 40 is a six valve, cross-linked configuration and includes a manifold 42 that is connected to the reservoir 18 via a reservoir valve 44 . Also in fluid communication with the manifold 42 are a plurality of valves 46 a - d and the plurality of springs 20 a - d . A front right valve 46 a controls fluid communication between the manifold 42 and the front right spring 20 a , a front left valve 46 b controls fluid communication between the manifold 42 and the front left spring 20 b , a rear right valve 46 c controls fluid communication between the manifold 42 and the rear right spring 20 c , and a rear left valve 46 d controls fluid communication between the manifold 42 and the rear left spring 20 d. [0020] A sensor 48 monitors pressure in the manifold 42 . The sensor 48 can be used to check pressure at each of the plurality of valves 46 a - d and the reservoir valve 44 to make sure that over-pressurization is not occurring. [0021] A crossover valve 50 is also in fluid communication with the manifold 42 . The crossover valve 50 controls fluid communication between front 20 a , 20 b and rear 20 c , 20 d springs, and controls fluid communication between right 20 a , 20 c and left 20 b , 20 d springs to vary stiffness as needed to maintain ground contact for all wheels. This will be discussed in greater detail below. [0022] The crossover valve 50 is in fluid communication with the manifold 42 at a position that can fluidly separate the springs for front 12 and rear 14 axles from each other. Each valve from the plurality of valves 46 a - d is in a normally closed position and the crossover valve 50 is in a normally open position. This would allow air to flow between the springs 20 a , 20 b on the front axle 12 and the springs 20 c , 20 d on the rear axle 14 once the valves 46 a - d are opened. [0023] When the crossover valve 50 is in a closed position, the manifold 42 is essentially cut in half with fluid communication being prevented between front springs and rear springs, i.e. air cannot flow between springs 20 a , 20 b on the front axle 26 and springs 20 c , 20 d on the rear axle 14 . [0024] When the front right 46 a and front left 46 b valves are open and the crossover valve 50 is closed, fluid communication only occurs between the front right 20 a and front left 20 b springs. When the rear right 46 c and rear left 46 d valves are open and the crossover valve 50 is closed, fluid communication only occurs between the rear right 20 c and rear left 20 d springs. Air pressure within one of the springs 20 a , 20 b can be increased to provide a greater stiffness while air in the other of the springs 20 a , 20 b would be decreased to provide a softer spring. This adjustment between right and left springs on a common axle provides stiffness attenuation as needed to maintain ground contact for all for wheels. [0025] A controller 60 , such as a computer, microprocessor, or electronic control unit for example, controls opening and closing of the crossover valve 50 and the plurality of valves 46 a - d . In one example, the controller 60 generates an electronic control signal to close the crossover valve 50 when a four-wheel drive low mode is activated. In this mode, the controller 60 also generates control signals to open the plurality of valves 46 a - d , and fluid communication occurs back and forth only between the right and left front springs 20 a , 20 b and only back and forth between the right and left rear springs 20 c , 20 d , i.e. fluid transfer only occurs right and left between two pairs of springs associated with the same axle. There is no fluid transfer between front 20 a , 20 b and rear 20 c , 20 d springs in this mode, i.e. fluid from the front springs 20 a , 20 b cannot be communicated to the rear springs 20 c , 20 d . If a predetermined speed limit is exceeded, or if a vehicle user de-selects the four-wheel drive low mode, the controller 60 generates control signals to open the crossover valve 50 and to close the plurality of valves 46 a - d resulting in a return to a normal operation mode. It should be understood that while a four wheel drive configuration is shown with front and rear drives axles, the subject air suspension system 16 could also be used with other types of axle configurations. [0026] As such, a single crossover valve 50 is included in the manifold 42 and is normally open to separate left and right portions of the valve block 40 . When this crossover valve 50 is closed, each valve from the plurality of valves 46 a - d can be opened to allow flow between left and right springs but not between front and rear springs. This configuration provides significant cost savings from a material and labor perspective. [0027] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.	An air suspension includes a crossover valve in fluid communication with a manifold, a first set of springs in fluid communication with the manifold through a first set of valves, and a second set of springs in fluid communication with the manifold through a second set of valves. The crossover valve is movable between an open position to allow fluid communication to each of the first and the second sets of springs and a closed position that separates the first set of springs from the second set of springs.	1
BACKGROUND OF THE INVENTION The present invention relates to an apparatus for and method of engaging the marginal edge portions of a ribbon of float glass, and further, to a drum-shaped edge roll for exerting forces on marginal edge portions of the ribbon. In a float forming process, molten glass is delivered onto a pool of molten metal and therafter formed into a continuous ribbon. Under the competing forces of gravity and surface tension, the molten glass spreads to an equilibrium thickness of about 0.27 inches (0.69 cm.). In order to produce glass ribbon of less than equilibrium thickness the ribbon is normally subjected to both longitudinal and lateral tractive forces while in a viscous state. Longitudinal tractive forces are generally exerted upon the ribbon by conveying means downstream from the float chamber. Such longitudinal forces may adversely affect the ribbon in at least two ways; by prompting a narrowing tendency, and by inducing optically undesirable surface variations in the ribbon. Such surface variations may take the form of longitudinally oriented distortions, e.g., corrugations. It is known in the glass manufacturing art to exert outwardly directly lateral tractive forces to the marginal edge portions of the viscous ribbon to control the narrowing tendency of the ribbon and produce lateral ribbon attenuation. Examples of such techniques may be found in the teachings of U.S. Pat. Nos. 3,450,518 to Itakura et al.; 3,520,672 to Greenler; 3,695,859 to Dickinson; 3,709,673 to Bishop; 3,929,444 to May et al.; 3,998,616 to Farabaugh and 4,157,908 to Gagne. Teachings of each of the above-mentioned patents are useful in the temperature and viscosity region where the ribbon is readily attenuatable, i.e., where ribbon temperature is between about 1800° F. (980° C.) and about 1500° F. (815° C.). It has been learned, however, that undesirable longitudinally oriented ribbon distortions may originate in a lower temperature region downstream of the typical attenuation region, e.g. between about 1500° F. (815° C.) and about 1250° F. (680° C.) The prior art has not recognized the existence of such a problem nor taught a method of diminishing the adverse effects of such distortions. Further, conventional prior art attenuating devices are not ideally suited for operation in the lower temperature range where such distortions may originate. U.S. Pat. Nos. 3,709,673 to Bishop; 3,929,444 to May et al.; and 3,998,616 to Farabaugh are exemplary of edge roll machines known in the glass manufacturing art which engage the marginal edge portion of the ribbon with a rotating disc-shaped edge roll having circumferentially positioned teeth. The edge roll is generally mounted on one end of a barrel which extends through the chamber side wall, and is driven from outside the chamber about an axis of rotation parallel to the barrel. The barrel is inserted into the chamber at an angle generally slightly downstream of a line normal to the ribbon's center line to provide the desired lateral component of force. Although these devices are useful in attenuating the ribbon in the traditional attenuation region, the devices are normally spaced about 10 feet (3 meters) apart on each side of the ribbon and each exerts a force upon the ribbon along only a very small portion of the marginal edge, effectively a point of applied force. As a result, they are relatively ineffective in supplying the increased lateral attenuation forces required in the lower temperature region where ribbon viscosity has increased. Further, the teeth of the subject devices have diminished ability to grip the lower temperature, higher viscosity ribbon, thus resulting in skidding rather than effective gripping, and further limiting effectiveness. U.S. Pat. No. 3,520,672 to Greenler teaches an edge roll machine having a plurality of closely spaced disc-shaped edge rolls, each mounted on individual barrels and commonly driven from without the chamber to rotate about an axis of rotation slightly downstream of a line normal to the ribbon's center line. Although this device provides more closely spaced forces to the marginal edge of the ribbon, there still remains at least the diameter of a single edge roll between adjacent points of force, and furthermore, the plurality of individual barrels may act as a considerable heat sink along the ribbon edge to create an undesirable temperature gradient thereacross. U.S. Pat. No. 3,450,518 to Itakura et al. teaches an edge grasping device including an elongated rod having a ribbon engaging hook secured to one end. The rod is extended through the chamber sidewall and reciprocated in a generally elliptical manner to cause the hook to intermittently grasp the ribbon edge and pull it laterally outward. Such a device exerts a force on a very small region of the ribbon and suffers from the previously discussed limitations related thereto. Further, the hook only engages the ribbon during about one half of its reciprocating path, leaving the ribbon disengaged during the remaining portion. U.S. Pat. No. 4,157,908 to Gagne teaches an edge engaging device having a toothed cylindrical member supported at one end thereof by a single elongated arm. The cylindrical member engages the ribbon and is rotated about an axis which extends generally in the direction of glass flow. This patent teaches that the cylindrical member be positioned such that its downstream end is imbedded into the surface of the glass while its upstream end remains above and disengaged from the surface of the glass to avoid a backup of the glass. Although useful in controlling ribbon thickness in the temperature region where the ribbon is readily attenuatable, the device is limited in its usefulness in the subject lower temperature region. The angled engagement between the cylindrical member and the ribbon surface limits the effective length of the cylindrical member, but more importantly, may be largely unattainable in the lower temperature ranges because of the relatively higher viscosity of the ribbon and corresponding increased resistance to indentations by objects having large surface areas. In the Gagne patent, glass engaging projections are moved in a lateral direction, but the major glass-impelling surfaces on the projections face the longitudinal direction, so that the major thrust of the worm gear action would be longitudinal. This is reinforced by the preference for making the projections elongated in the circumferential direction. Thus, the Gagne arrangement is not adapted for maximizing lateral forces. An article in the Journal of the American Ceramics Society, Vol. 6, No. 1-2, January-February 1977, pp. 1-5, by O. S. Narayanaswamy teaches a method of attenuating a float glass ribbon which includes advancing molten glass to a bath entry region where it freely flows to equilibrium thickness, then advancing it downstream to a cooled, high viscosity (1300° F. (700° C.), 10 8 poises) region of equilibrium thickness, followed by advancement through a region where the glass is reheated and attenuated to less than equilibrium thickness. The intermediate high viscosity region includes a pair of opposed conventional edge rolls which grip the ribbon to counteract the downstream longitudinal tractive force and prevent its transmission into the bath entry region. The article does not address the problem of diminishing longitudinal distortion in the ribbon after attenuation occurs. It would be advantageous to have a method of attenuating float glass which would diminish longitudinal distortion in the final product. It would also be advantageous to have a device capable of effecting such a result which is operable in a relatively low temperature, high viscosity region of the float chamber. U.S. Pat. No. 4,342,583 to Kapura and Goode is directed to related subject matter. SUMMARY OF THE INVENTION The invention relates to means for and a method of attenuating a ribbon of glass by providing a cylindrical member having ribbon engaging elements, e.g., teeth or ridges, about its circumferential surface, supporting the cylindrical member with its lower circumferential surface adjacent and substantially parallel to the ribbon surface, and rotating the cylindrical member about an axis of rotation which is generally parallel to the direction of ribbon flow. Such rotation enables the ribbon engaging element to engage the ribbon to positively exert laterally outward tractive forces thereto. Rotation of the cylindrical attenuating device permits application of enhanced lateral forces to the glass ribbon. Orientation of the cylinder with its axis substantially parallel to the direction of glass travel results in an attenuating force having a major component in the lateral direction and little or no component in the longitudinal direction. By "substantially parallel" is meant that the axis of the cylinder may be at an angle less than 45° with respect to the longitudinal direction of glass travel. A slight angle is usually preferred so that each glass-engaging projection may be moved in the glass with a longitudinal component of velocity that approximates the longitudinal velocity of the glass ribbon, thereby imparting little or no longitudinal force to the ribbon. Another way of describing the action of preferred attenuating means of the present invention on the glass is in terms of the "plowing" effect created by the glass-engaging projections carried by the rotating cylinder. Each projection may have a major glass-impelling surface extending substantially radially and substantially parallel to the axis of the cylinder (i.e., within 45°), whereby the glass-impelling surfaces meet the glass substantially normal to the direction of movement of the projections as the cylinder is rotated about its axis. The projecting members may be discrete teeth or elongated ridges, including ridges that extend helically around the cylinder. Another aspect of the invention relates to traction between a cylindrical attenuator and the glass. Improved traction may be attained by providing teeth on the cylinder in a relatively widely spaced pattern so that a plurality of teeth contact the glass simultaneously, but no two teeth engage the glass within four centimeters of each other along the axial direction. For the same reason, it is preferred that teeth be spaced circumferentially so that in any given segment of the cylinder (e.g., about four centimeters in the axial direction) no more than one tooth engages the glass at one time, and preferably as one tooth disengages the glass as the next tooth simultaneously comes into contact with the glass. Furthermore, increasing the total number of teeth in contact with the glass at any given time, when spaced as set forth above, will increase the total amount of tractive force attainable by the cylinder. Accordingly, it is desirable to provide the cylinder with sufficient length to accommodate a plurality of spaced apart, simultaneously contacting projections. Providing at least three simultaneous contact points is preferred, and providing at least five is most preferred. The present invention has particular applicability to attenuating a ribbon glass to diminish undesirable longitudinally oriented surface distortions which are produced in the ribbon both in the traditional attenuation region and downstream therefrom, by the positive application of outwardly directed lateral forces in the region where the ribbon has a temperature less than about 1500° F. (815° C.), which is cooler and farther downstream than conventional attenuation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmented schematic plan view of a float chamber having portions of the roof removed to show edge engaging devices operating according to a preferred embodiment of the present invention. FIG. 2 is an elevated side view of an edge engaging device incorporating features of the present invention taken along line 2--2 of FIG. 1. FIG. 3 is a view, having portions removed for clarity, taken along line 3--3 of FIG. 1, showing an edge engaging device incorporating features of the present invention. FIG. 4 is an end elevational view taken along line 4--4 of FIG. 3 showing the orientation of teeth about the outer circumferential surface of the edge engaging device. FIG. 5 is a view smilar to the view of FIG. 3 showing a second embodiment of the present invention. FIG. 6 is a view similar to the view of FIG. 3 showing a third embodiment of the present invention. FIG. 7 is an enlarged cross-sectional view of the left hand portion of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, there is shown a float glass forming chamber 20 of the type known in the glass manufacturing art. The chamber 20 generally consists of a refractory backwall 26, refractory sidewalls 28, a refractory roof 30, a refractory bottom 32 (shown only in FIG. 2), and a refractory end dam 34 adjacent a discharge end 35. In general, a ribbon 22 of glass is formed in chamber 20 from a mass of molten glass which is delivered upon a pool 24 of molten metal, e.g., tin or an alloy thereof. The ribbon is advanced downstream upon the pool 24 in the direction of the arrow by a plurality of lift out rolls 36 located near the discharge end 35 of the chamber 20. As the ribbon advances downstream it generally cools from an initial temperature of about 2000° F. (1100° C.) to about 1100° F. (595° C.) at the discharge end 35. Although not limiting to the invention, it is generally desirable to deliver a mass of molten metal onto the pool 24 in any convenient manner at a relatively high initial temperature, i.e., 2000° F. (1100° C.), and maintain the glass in a relatively high temperature range, e.g., from about 2000° F. (1100° C.) to about 1700° F. (925° C.), for a relatively long residence time. Such a region is designated region A in FIG. 1 and represents a relaxation zone where the relatively low viscosity of the glass encourages equilibration of flow perturbations arising from the delivery onto the pool 24. Accordingly, in region A the glass is generally either greater than or equal to equilibrium thickness. Region B of FIG. 1 represents an attenuation region of the chamber 20 in which the ribbon 22 is stretched to a thickness less than equilibrium thickness in any convenient manner. Although not limiting to the invention, the glass may enter region B at a temperature of about 1800° F. (980° C.) and is typically cooled while passing therethrough to a temperature of about 1500° F. (815° C.) at the downstream end. The glass is drawn from region A into region B and therethrough by longitudinal forces which are exerted upon the glass by the lift out rolls 36 adjacent the discharge end 35 of the chamber 20. Such longitudinal forces produce a desirable reduction in thickness in the ribbon in region B, but also tend to produce an undesirable reduction in ribbon width due to surface tension forces in the ribbon. For this reason it is common in the glass manufacturing art to also exert lateral stretching forces on the ribbon in region B. Top edge rolls as taught in U.S. Pat. No. 3,929,444, gas jets as taught in U.S. Pat. No. 3,440,030, which teachings are incorporated herein by reference, and other means may be utilized in region B to exert such lateral stretching forces. The lateral stretching forces may be controlled in region B so as to increase ribbon width, maintain a constant ribbon width, or produce a controlled reduction in ribbon width, as taught in U.S. Pat. Nos. 3,440,030, 3,843,346, and 3,695,859, which teachings are also incorporated herein by reference. Region C of FIG. 1 represents a region of the chamber 20 wherein the ribbon has a temperature between about 1500° F. (815° C.) and the discharge temperature of about 1100° F. (595° C.). Because of the ribbon's relatively high viscosity in this region it has heretofore generally been considered impractical and ineffective to exert lateral stretching forces upon the ribbon in region C. Accordingly, it has been customary to effect a major portion of the ribbon attenuation in region B by the application of both lateral and longitudinal stretching forces, after which the ribbon 22 was advanced thorugh region C and cooled without the application of lateral stretching forces. Some portion of the total attenuation may occur in region C, but it has heretofore been accompanied by a corresponding decrease in ribbon width due to ribbon surface tension forces. To minimize this corresponding decrease of ribbon width, it is common to rapidly cool the ribbon upon entry into region C. It has been determined, however, that undesirable longitudinally oriented surface distortion patterns may originate in the ribbon 22 in region C. It is believed that such distortion patterns may be a result of the longitudinal tractive forces exerted upon the ribbon 22 by downstream conveying rolls and the above-mentioned decrease in ribbon width produced thereby. Additional distortion is believed to be caused by the rapid cooling needed in region C to avoid undue ribbon width decrease. Such surface distortion patterns may take the form of corrugations in the ribbon, which will diminish the optical quality of the final ribbon according to the relationship: P=khf.sup.2 where P is the optical power of the distortion, k is a constant, h is the amplitude of the surface defect, and f is the spatial frequency of the distortion pattern. In a preferred application of the present invention, outwardly directed lateral forces are positively exerted to the ribbon in region C to diminish or eliminate the effect of such longitudinally oriented distortion patterns. More particularly, the lateral forces are applied to reduce the amplitude, h, and spatial frequency, f, of the pattern, with a particular interest in reducing the spatial frequency f because of its second power relationship with the optical power, P. Moreover, application of such lateral forces in region C permits the cooling of the ribbon to be effected in a more gradual and natural manner, thus avoiding distortion problems which were previously encountered due to rapid cooling. Because of the relatively high viscosity of the ribbon 22 in region C, it is desirable to exert relatively large lateral stretching forces on the ribbon to produce the desired result. Of course, the edge engaging devices of the present invention may also be utilized in region B for traditional attenuation activities. Referring to FIG. 1, edge engaging devices 38, incorporating features of the present invention, are utilized in region C to positively exert relatively large lateral stretching forces in order to control ribbon width therein and diminish distortion effects. More particularly, edge engaging devices 38 may be utilized to increase ribbon width, maintain ribbon width at a constant value, or establish a controlled decrease in ribbon width. Each of the devices 38 includes a support facility 40 positioned outside the sidewall 28, a pair of spaced, elongated arms 42 and 44 which extend through a sealable opening 45 in sidewall 28, and a glass engaging member 46. The glass engaging member 46 is preferably generally cylindrical or drum shaped and is rotatably mounted along its longitudinal axis between the extended ends of arms 42 and 44 in a manner to be discussed below. As shown in FIG. 1, the member 46 is positioned such that its cylindrical axis is generally parallel to the direction of glass travel or the longitudinal centerline of the ribbon 22, as shown in FIG. 3, with its lower circumferential surface generally parallel to the surface of the ribbon 22. Referring to FIGS. 3 and 4, the glass engaging member 46 includes an outer cylindrical member 47 having a plurality of discrete teeth 48 secured to the outer circumferential surface thereof. In a preferred mode of construction, the teeth 48 are mounted in spaced relation along a strap 50 which has beveled edges, which edges are captured in a complementarily beveled groove 52 in the surface of the member 47, and retained therein by set screws 54. In this manner, discrete teeth 48, or rows thereof, may be conveniently replaced without requiring replacement or re-machining of the glass engaging member 46. Replacability of teeth permits optimizing the effectiveness of the glass engaging member 46 when it is utilized in different regions of the chamber 20, as different teeth configurations may be more efficient in different regions. The teeth 48 which are used in region C may be relatively long and sharp, and may take the form of cones or pyramids as shown in FIGS. 3 and 4. Alternatively, and with reference to FIG. 5, teeth 49 may have a rectangular base having a lengthwise dimension parallel to the axis of the cylindrical member 47. Preferably, such teeth have a relatively sharp apex also lying substantially parallel to the axis of the cylindrical member 47. Because ribbon movement is generally parallel to the axis of the cylindrical member 47, such an arrangement of the teeth 49 minimizes impedance to the ribbon flow while also presenting a relatively large surface area for gripping the ribbon in the lateral direction. The elongated cylindrical shape of the glass engaging members 46 enables greater traction to be attained relative to conventional attenuating wheels or multiples thereof in that a large number of glass contact points can be provided on a single device. Thus, cylindrical member 46 preferably carries a pattern of projections 48 or 49 such that at least three of the projections contact the glass at any given time. In the most preferred cases, at least five simultaneous contact points are provided. The projections may be arranged in rows as shown in FIGS. 3 and 5, or they may be arranged in a less regular array on the cylinder. Increasing the number of contact points within a relatively small area is an advantage of the present invention, but reducing the spacing between contact points unduly can have a negative effect on traction. The minimum spacing will depend upon the viscosity of the glass in the particular region being contacted as well as other factors, but for operating in region C it is preferred that the projections be spaced so that projections contacting the glass at any given time are at least four centimeters apart in the direction of the axis of the cylinder. Circumferentially, the spacing may be closer, provided that a first projection disengages from the glass before a subsequent projection engages the glass within four centimeters axially of the first projection. Referring to FIG. 6, a strap 51 having a continuous ridge formed on its outer surface may be optionally utilized on cylindrical member 47 instead of discrete teeth 48 or 49. Preferably the glass engaging ridge of strap 51 has a relatively sharp apex angle to promote efficient ribbon gripping when such an arrangement is used in region C of the chamber 20. The ridges may be parallel to the axis of the cylinder, or they may be slightly helical as shown in FIG. 6. The pitch of the helix is such that the ridges make an angle less than 45° with the axis of the cylinder. Referring to FIGS. 1 and 2, the support facility 40 of edge engaging device 38 may provide for vertical adjustment of the engaging member 46, upstream or downstream adjustment of engaging member 46, and inward and outward adjustment of the position of engaging member 46 with respect to the ribbon 22. Facilities known in the glass manufacturing art, such as floor mounted carriages as shown in FIG. 2 and as taught in U.S. Pat. No. 3,709,673, which teachings are herein incorporated by reference, may be modified conveniently to support the pair of elongated arms 42 and 44. Alternatively, an overhead-mounted support facility such as taught in U.S. Pat. No. 3,929,444, which teachings are incorporated by reference, may be conveniently utilized. When stretching the ribbon laterally outward, the edge engaging devices are preferably angled as shown in FIG. 1 so that the engaging members 46 are oriented with their downstream ends closer to the center of the ribbon. The direction of glass travel, designated by line 66, and the direction of the axis of an engaging member (in this case the member on the left of FIG. 1), designated by lfne 67, form angle θ, which is between 0° and 45°. With the rotating member thus angled, the projections on the cylinder move in contact with the glass with a lateral and a longitudinal component of velocity. The longitudinal component is minor, but by coordinating the speed of rotation of the cylinder with the ribbon speed, the longitudinal component may closely approximate the ribbon speed so that little or no force is applied to the ribbon in the longitudinal direction. As a result, attenuation in accordance with the present invention need not involve longitudinal stretching. Likewise, resistance to downstream movement of the ribbon is avoided. At the same time, because the major velocity component of the projections is in the lateral direction, substantial lateral tractive force may be developed. This enhanced lateral force permits lateral attenuation in regions where conventional attenuating means have been considered impractical because of low traction. Referring now to FIGS. 3 and 6, an end of the engaging member 46 is rotatably mounted to an end of adjacent elongated arm 42 or 44 by a hollow shaft member 50, which is sealingly secured to the end of the engaging member 46 at one end and extends into the interior of elongated arm 42 or 44 through an opening in the inside vertical wall portion 53 thereof. The hollow shaft member 50 is rotatably mounted within the elongated arm 42 or 44 by bearings 55. Because of the high temperatures encountered within the forming chamber 20, it is desirable to cool the engaging member 46. Accordingly, cooling fluid is passed through elongated arm 42 and hollow shaft 50 to the engaging member 46 and therethrough to elongated arm 44, as illustrated by fluid flow arrows of FIGS. 3 and 6. A solid inner cylindrical member 57 is conveniently mounted inside the engaging member 46 by baffle plates 54, to divert and localize the flow of cooling fluid to the areas adjacent the surface portions of the other cylindrical member 47 (as shown by fluid flow arrows). In this manner the weight of the engaging member 46 is minimized and cooling capacity is utilized more effectively. Referring to FIG. 6, it is important to assure that cooling fluid remains within a closed system and does not escape into the atmosphere of the forming chamber 20. Likewise, it is important to protect the interior components of the edge engaging device 38 from attack by the hostile gaseous atmosphere of the forming chamber 20. Accordingly, a sealing system is utilized in the present invention, including a sealing ring 56 which is retained in position adjacent to the rotatable hollow shaft 50 by a retainer ring 58. The sealing ring 56 forms a hollowed-out groove 60 which surrounds a closed path portion of the hollow shaft 50. In order to prevent egress of cooling fluid and ingress of hostile chamber atmosphere along the outer surface of the rotatable shaft 50, the groove 60 is purged with a pressurized fluid flow. Preferably, a gaseous sealing medium is supplied to the groove 60 through inlet tubes 61 at a pressure in excess of the pressure of both the cooling fluid and the hostile gaseous atmosphere, e.g., 90 lbs/in. 2 , thus setting up a gaseous curtain which prevents communication therebetween. A gaseous sealing medium is selected which is compatible with both the chamber atmosphere and the interior of the engaging device 38, e.g., nitrogen gas. As shown in FIG. 6, conventional sealing rings 62 may be secured to the wall 53 by a retainer 63 to serve as a secondary sealing system. With continued reference to FIG. 6, the engaging member 46 may be rotatably driven by a sprocket and chain assembly 64 secured to the interior end of hollow shaft 50 within elongated arm 42. A source of driving force 65, e.g., an electric motor, may be conveniently mounted on the support facility 40 to drive the sprocket and chain assembly 64. Alternatively, a reciprocating arm linkage may be disposed within the elongated arm 42 to drive the engaging member 46. The present invention is not intended to be limited by the description of the preferred embodiment disclosed herein. Rather, it is defined by the claims which follow.	A cylindrical ribbon engaging device is rotated about an axis of rotation substantially parallel to the direction of ribbon flow to positively exert lateral forces to an elongated substantial continuum of the marginal edge portion of the ribbon. Provisions are made to maximize lateral forces while minimizing longitudinal forces.	2
FIELD OF THE INVENTION The present invention generally relates to medical devices and methods. More particularly, the present invention relates to apparatus and methods for the ultrasonically enhanced delivery of therapeutic or contrast agents within the vascular and lung areas or other corporeal lumens. BACKGROUND OF THE INVENTION Despite the significant progress of medical technology, vascular and lung diseases, as well as arterial thrombosis (blood clots in arteries), remain frequent, costly and serious problems in health care. Current methods of treatment such as drugs, interventional devices, and/or bypass surgery are usually expensive and not always effective, even sometimes causing additional problems. For example, drugs can also dissolve beneficial clots or interventional devices can injure healthy tissue to cause potentially fatal bleeding complications or to form scarring or cellular growth which may itself eventually become a serious obstruction in, for example, a blood vessel (a process known as restenosis). Ultrasonic energy has been used for enhancing the intravascular delivery of drug, to dissolve clot acoustically, disrupt mechanically and inhibit restenosis. Such energy can be delivered intravascularly using specialized catheters having ultrasonically vibrating surface at or near their distal ends. One type of ultrasonic catheter delivery system uses a wire or other axial transmission element to deliver energy from an ultrasonic energy source, located outside the patient to the internal organs, to desired corporeal lumens. (See, for example, U.S. Pat. Nos. 5,002,059, 5,324,255, 5,345,940, and 5,699,805, each of which is incorporated herein by reference.) Such catheters are rigid and cannot be easily inserted through narrow and tortuous vessels and may cause serious damage to vascular walls. A second type of catheter has ultrasonic transducers mounted directly on their distal ends. See, for example; U.S. Pat. Nos. 5,362,309, 5,318,014, 5,315,998, 5,269,291, 5,197,946, 6,001,069, and 6,024,718, each of which is incorporated herein by reference. Despite enhanced safety and the fact that there is no need to employ a transmission element along the entire length, these catheters suffer from limited ultrasound energy, and the transducer-catheter design is still problematic. Another type of catheter has an ultrasonic transducer or ultrasound transmission element with a central orifice in the distal end to impart ultrasonic energy into liquid and simultaneously deliver it to a corporeal lumen. See, for example, U.S. Pat. Nos. 5,735,811 and 5,197,946, each of which is incorporated herein by reference. Although these catheters are more effective and liquid delivery is more convenient, there are design difficulties and limitation of ultrasound energy from longitudinal waves. OBJECT OF THE INVENTION It is an object of the invention to provide an improved method and device for catheter drug delivery. It is also an object of this invention to provide a method and device for catheter drug delivery using ultrasound energy. It is another object of the invention to mix different drugs ultrasonically and deliver them to a desired corporeal lumen ultrasonically. It is a yet another object of the invention to mix drug-liquid solutions with a gas (for example, saline with oxygen) ultrasonically and deliver the mixture to a desired corporeal lumen ultrasonically. It is a further object of the invention to provide a method and device for delivering drugs to an intravascular area or/and a corporeal lumen, to dissolve blood clots. It is a yet further object of the invention to treat a blocked and narrowed blood vessel with ultrasound waves. These and other objects of the invention will become more apparent from the discussion below. SUMMARY OF THE INVENTION The present invention relates to apparatus and method for the ultrasonically enhanced delivery of therapeutic or contrast agents within the vascular and lung area or other desired corporeal lumens. Ultrasonic waves are applied to a vascular area, lung or any corporeal lumen without requiring direct contact between ultrasound transducer tip and the patient's body, particularly to dissolve blood clots. According to the present invention, a catheter system comprises an ultrasound transducer having a distal tip with a radial surface and a distal end surface. The ultrasound transducer is disposed in a chamber at the proximal end of the catheter, and the transducer radiation surface or tip directs ultrasound waves or energy forward into the catheter coaxially via liquid. Longitudinal ultrasound waves induce wave motion in fluid adjacent to the transducer distal end. While particularly intended to enhance the absorption of therapeutic agents delivered to certain body lumens, the catheter system of the present invention is also useful for the delivery of ultrasonic energy to a desired location. The transducer radiation surface or transducer tip, may be cylindrical, flat, concave, convex, irregular or have a different shape-geometry to radiate ultrasound energy into catheter. The catheter of the present invention may comprise a proximal tubing for delivering therapeutic agent from a reservoir by pump or syringe. The tubing may be located in front of or behind the radiation surface. In a first embodiment of the invention, an ultrasound transducer and tip are mounted in a proximal portion of a catheter body, located outside of the body of a patient. The remainder of the catheter distal to the proximal portion may be inserted into a blood vessel or attached to a body lumen, to drive a therapeutic agent ultrasonically and/or deliver ultrasonic energy. In a second embodiment, the distal tip of the transducer does not have an orifice, which is very important to create and deliver ultrasound energy fully to a vessel or body lumen. In a third embodiment, the catheter system comprises a catheter body, mechanically coupled with an ultrasound transducer through a housing or tip node, which is where the transducer body is outside the catheter. In this way, the catheter body can be provided with two or more tubing inlets (sleeves) for different therapeutic agents, even one or more different gases such as oxygen, and agents to be mixed and delivered ultrasonically. The catheter system of the invention is particularly advantageous on tissues for which local topical application of a therapeutic agent is desirable but contact with the tissue is to be avoided. Furthermore, ultrasound waves used in the method energize the drug, dissolve the clots and cause the penetration of the drug within the narrow and blocked vessels. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective, partly cross-sectional view of an ultrasonic catheter drug delivery system for use according to the present invention; FIG. 2 is a lateral view of an ultrasonic catheter system chamber of the invention with two horizontally located sleeves; FIG. 3 is a frontal view of an ultrasonic catheter system chamber of the invention with three peripherally located sleeves; FIG. 4 is a lateral, cross-sectional view of a catheter system chamber, mechanically coupled with an ultrasound transducer through the tip; and FIG. 5 is a lateral, cross-sectional view of an ultrasonic catheter drug delivery system for delivering therapeutic agent to the catheter body or chamber through a central orifice of the ultrasonic tip. DETAILED DESCRIPTION OF THE INVENTION The present invention is a method and device, which provides treatment of luminal conditions, particularly for the treatment of coronary and peripheral arterial disease and thrombosis, where the purpose is to dissolve or disrupt the clot, plague or other stenotic lesions which cause the disease, and for dilation of narrowed vessels. The method and device of the present invention also useful to enhance the administration of therapeutic agents primarily responsible for the disruption of the clots or other stenotic material. The ultrasonic energy agitates and promotes the penetration of the drug into the stenotic material. Due to delivery of therapeutic agent and ultrasound energy through the agent, this method and device of the present invention are further useful for treatment of other body lumens, such as the urethra, ureter, fallopian tubes, or urological disorders related with prostate gland (BPH—Benigh Proctatic Hyperplasia), and can be used for impotency (erectile dysfunction) treatment by ultrasonically stimulating sexual organs, urinary tract, and the like. The present invention can be used for targeted and localized drug delivery for treatment of lung, vasculature, vasopasm and tumor treatment. In addition, this invention is very useful for the treatment of closed wounds as a fistulas, canals, etc., by destroying bacteria cells and stimulating healthy tissue cells. The invention can perhaps be better appreciated by referring to the drawings. FIG. 1 is a perspective view of ultrasound catheter drug delivery system 2 , comprising an ultrasound generator 4 , a connector 6 operatively connecting ultrasound generator 4 with a transducer 8 , a housing 10 surrounding transducer 8 , and a catheter 12 having a proximal portion 14 with a chamber 16 containing a therapeutic agent 18 . Transducer 8 has a tip 20 with a radial surface 22 and a distal radiation surface 24 . Chamber 16 is in fluid communication through tubing 26 with a fluid source 28 , and directly with at least one lumen 30 of the distal portion 32 of catheter 12 that extends to catheter distal end 34 . Fluid source 28 can be, for example, a reservoir with a pressure pump or syringe. The proximal section 36 of catheter proximal portion 14 sealingly engages housing 10 . Preferably the inner surface 38 of proximal section 36 has threads 40 that engage reciprocal threads 42 on the outer surface 44 of housing 10 . This arrangement will allow the operator to vary the distance between distal radiation surface 24 and the distal end 46 of chamber 16 to regulate ultrasonic pressure and energy level. While radial surface 22 can be smooth or substantially smooth, it is preferred that this surface is not smooth, for example, with rings, threads, barbs, or the like, which will create more ultrasonic pressure in catheter 12 . In the embodiment of the invention shown in FIG. 1, ultrasonic energy at a pre-selected frequency is sent through the catheter 10 with fluid such as a therapeutic agent as a transmission member. Ultrasound energy will pass through therapeutic agent 18 to catheter distal end 34 . Catheter 12 may be formed from a conventional rigid or flexible material, dependent upon the application. It would be appropriate for catheter 12 to be flexible if the catheter is to be inserted into tortuous vascularity or if catheter distal end 34 is to be attached to a vessel, fistula, or the like. It is provided that the distal radiation surface is driven with a constant, modulated or pulsed frequency. It is also provided that the distal radiation surface is driven with a sinusoidal, rectangular, trapezoidal or triangular wave form. It is further provided that the transducer is capable of being operated at a frequency from 10 kHz to 10,000 MHz. A second embodiment of the invention is shown in FIG. 2, where transducer 50 is fixedly, optionally removably, attached to the proximal section 52 of the proximal portion 54 of a catheter 56 . Transducer 50 has a tip 58 with a radial surface 60 and a distal radiation surface 62 . Catheter proximal portion 54 has a chamber 64 with a therapeutic agent 66 that is in fluid communication with each of two fluid sources 68 , 70 through lumens 72 , 74 , respectively. Fluid sources 68 , 70 may provide two or more fluids, e.g., liquid or gas, such as saline or oxygen, to be ultrasonically mixed and delivered through lumen 76 to catheter distal end 78 . FIG. 3 is a semi-cross-sectional view of the proximal end of a catheter according to the invention wherein three fluid sources 80 are each in fluid communication through a lumen 82 with chamber 84 of catheter proximal section 86 . The distal radiation surface 88 of a transducer (not shown) is positioned within chamber 84 . In FIG. 4, a connector 110 operatively connects an ultrasound generator (not shown) with a transducer 112 , which has a tip 114 with a radial surface 116 and a distal end surface 118 . A catheter 120 has a proximal portion 122 with a chamber 124 containing a therapeutic agent 126 . Chamber 124 is in fluid communication through tubing 130 with a fluid source 132 , and directly with at least one lumen 134 of the distal portion 136 of catheter 120 that extends to catheter distal end 140 . Fluid source 132 can be, for example, a reservoir with a pressure pump or syringe. The proximal section 142 of catheter proximal portion 122 sealingly engages radial surface 116 . Chamber 124 must be attached to ultrasonic transducer distal tip 114 at the mechanical resonant node, such as node 144 . If chamber 124 is not connected to the resonant node (either a little before or a little after the mechanical node), the intensity of the ultrasound energy at distal end 140 will be attenuated, i.e., damped, and ultrasound waves and/or energy will be transferred to the walls of chamber 126 , possibly damaging the chamber 126 structure assembly, which may cause leakage. In the embodiment of the invention set forth in FIG. 5, a connector 150 operatively connects an ultrasound generator (not shown) with a transducer 152 , which has a distal tip 154 with a radial surface 156 and a distal end surface 158 . A catheter 160 has a proximal portion 162 with a chamber 164 containing a therapeutic agent 166 . Transducer distal tip 154 has a central orifice 170 . Chamber 164 is in fluid communication with at least one fluid source 172 through central orifice 170 , which can be smooth, waved, ringed, slotted, grooved, or threaded, and infusion lumen 174 within tubing 176 . Two or more fluid sources 172 and infusion lumens 174 can mix and deliver different therapeutic agents. Chamber 164 is also in fluid communication with lumen 180 in the distal portion 182 of catheter 160 that extends to distal end 184 . The non-smooth surface of orifice 170 , such as rings or threads, increases the pressure of liquid in chamber 164 . Chamber 164 should be attached to ultrasonic transducer distal tip 158 at a mechanical resonant node, such as node 190 . Similarly, each lumen 174 should intersect central orifice 170 at a resonant node, such as node 192 . The catheter systems herein are comprised of conventional materials. The transducer and catheter chamber are preferably comprised of suitable metallic or even polymeric substances. Most preferably the transducer distal tip is comprised of a metal such as titanium or nitinol. As is mentioned throughout, the invention here can deliver one or more liquid or gaseous substances to a catheter distal end. Such substances include, but are not limited to, therapeutic agents such as antibiotics or antiseptics, saline, oil, water, oxygen, anticoagulants such as heparin or cumadine, or even liquid medical polymers, or mixtures of two or more thereof. The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, however, that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the spirit of the invention or the scope of the appended claims.	An ultrasonic catheter drug delivery device comprises an ultrasound transducer to produce ultrasonic waves, which transducer is mechanically attached to a catheter body or chamber. The ultrasonic transducer has a distal tip with a distal radiation surface, and when a therapeutic agent from a fluid source is directed to the catheter body or chamber, the radiation surface creates ultrasonic pressure and delivers liquid and simultaneously ultrasonic energy to a patient's vascularity or a selected body lumen. The method applies therapeutic agent and ultrasonic waves to the vascular area, lung or any body lumen without requiring direct contact between ultrasound transducer and body, dissolves blood clots, and stimulates tissue cells.	0
CROSS REFERENCE TO RELATED APPLICATION [0001] This application is related to and claims priority from earlier filed provisional patent application Ser. No. 61/252,750, filed Oct. 19, 2009, the entire contents thereof is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] The present invention relates generally to devices and apparatuses for launching projectiles, such as paintballs. These devices are commonly called paintball guns or paintball markers. The present invention, more specifically, relates to the bolt and valve mechanism in such devices and apparatuses that are employed for preparing the gas behind the projectile and then releasing the gas for launch of the projectile. For ease of discussion and illustration, the present invention will be discussed in connection with launching a paintball, as an example projectile, and a paintball marker as an example of a device that incorporates the mechanism of the present invention. However, it should be understood that this invention relates to and can be used in any type of gas projectile launcher for launching any type of projectile. [0003] In the prior art, gas powered guns or markers are well known in the art. In general, these devices include a supply of gas that fills a chamber, which is then emptied to launch a projectile, namely, a paintball. Valving is typically provided in the marker to control the flow of gas therein. In the prior art, various types of bolts and valving can be employed. For example, electrically operated solenoid valves and mechanical valves have been employed for this purpose. One example of such a mechanical valve used in paintball markers is a “spool” valve. These are so well known that they need not be discussed in detail herein. These spool valves are very common for use in connection with paintball markers. [0004] Gas within a marker not only provides power for launching a projectile but also is commonly used to control loading and launching of the projectile. In other words, gas can also be used to control bolt movement within a marker to, in turn, control position of a paintball. There are number of prior art patents that use this concept. U.S. Pat. Nos. 6,035,843 and 5,613,483 both use the existing gas supply for bolt control. The gas pneumatically actuates the bolt back and forth, as desired. Also, springs can be used for actuation of the bolt in certain directions. In these sample prior art systems, a unitary bolt construction is used for the dual purpose of controlling flow of gas to a storage chamber to serve as the power to launch the projectile and as well as serving as a conventional bolt that moves the projectile to a launch position while preventing additional projectiles from entering the breech. [0005] Essentially, prior art bolt unitary constructions typically have a standard bolt at one end and a gas control at the opposing end so that its actuation back and forth can be pneumatically controlled. The bolt reciprocates back and forth within the marker. With the appropriate timing, gas fills the appropriate chamber with the bolt assembly when the bolt construction is rearwardly positioned. When the bolt moves forward, the paintball is moved forward into a launching position. This forward motion causes the appropriate passageways within the marker so that the stored gas is released behind the paintball for launching thereof. [0006] As can be seen in FIGS. 1 and 2 , two examples of such prior art projectile launching devices are shown. More specifically, the prior art bolt and air release mechanisms are shown to illustrate the preparation and use of gas to launch a paintball. These existing prior art paintball markers typically have linear reciprocating bolt mechanisms. These prior art markers always have an empty volume within the marker that is situated between the back of the paintball and the air release valve. The air release valve is the device that releases the blast of gas that is used to propel the paintball. [0007] Referring first to FIG. 1 , a prior art paintball marker 10 includes an outer housing 12 with a barrel 14 connected thereto with a breech 16 for receiving a paintball 18 , via a feed tube 19 , from a hopper (not shown) or the like. A sliding bolt 20 is provided inside the housing 12 . The first portion 20 a of the bolt 20 communicates with the paintball 18 to be launched while the second portion 20 b of the bolt 20 communicates with an o-ring 26 to form of a poppet valve. In this case, the second portion 20 b of the bolt 20 provides an airtight seal to secure a firing gas chamber 24 . Gas is supplied, in the typical fashion and using known constructions, such as solenoid valves and the like (not shown), to the chamber 24 behind the seal. As the bolt 20 moves forward, the paintball 18 is moved into the launch position in the barrel 14 , as indicated by the arrows inside the bolt. With further forward movement of the bolt 20 , the second portion 20 b of the bolt 20 separates from o-ring 26 at region 20 c to break the seal 26 therebetween. This permits gas in chamber 24 to fill the empty chamber 28 inside the bolt 20 to, in turn, launch the paintball 18 . For this prior art configuration, filling chamber 28 for each firing cycle requires substantial amounts of additional gas. [0008] Similarly, in FIG. 2 , this prior art paintball marker 50 includes an outer housing 52 with a barrel 54 connected thereto with a breech 56 for receiving a paintball 58 from a hopper (not shown) or the like. A sliding bolt 60 is provided inside the housing 52 . The front end 60 a of the bolt 60 communicates with the paintball 58 to be launched while the rear end 60 b of the bolt 60 communicates with a gas release member 62 to form of a poppet valve. In this case, the valve interconnection between the bolt 60 and the gas release member 62 is of a slightly different configuration where the free front end 62 a of the gas release member 62 slidably engages with the inner surface 60 c of the bolt 60 . The rear opening 60 d of the bolt 60 still provides an airtight seal with the gas release member 62 via an o-ring 64 , for example. Gas is supplied, in the typical fashion, as above, and using known constructions, such as solenoid valves and the like (not shown), to the chamber 66 behind the seal between the gas release member 62 and the bolt 60 . As the bolt 60 moves forward, the paintball 58 is moved into the launch position in the barrel 54 , as indicated by the arrows inside the bolt. The gas release member 62 separates from the rear end 60 b of the bolt 60 to open the seal therebetween thereby permitting release of the gas trapped in the chamber 66 to fill the empty chamber 68 inside the bolt 60 to, in turn, launch the paintball 58 . For this prior art configuration, filling chamber 68 for each firing cycle requires substantial amounts of additional gas. [0009] In both of these example prior art devices, in FIGS. 1 and 2 , a large chamber behind the paintball and within the bolt must be filled prior to a paintball launch with air released from the firing chamber, behind the seal, for later complete evacuation such launch. In these prior art bolt and valve constructions, gas is wasted during every shot by having to fill this empty chamber volume in the bolt from the air released from the firing chamber during every shot. This volume is not an inconsiderable amount and having to fill it every shot has a detrimental effect on the overall efficiency of the marker thereby drawing gas from the cylinder faster than necessary. It is highly desirable to avoid such wasted gas. [0010] While these prior bolt constructions effectively control gas flow and launching of a paintball, they suffer from many disadvantages that result from inefficiencies in the flow and use of gas within a marker. This is of high concern because paintball is played with paintball markers that operate off compressed air or compressed carbon dioxide. The presence or amount remaining of a source of gas is, therefore, of concern for operation of these markers. These gases are typically carried in compressed gas cylinders that are either mounted directly to the paintball marker, or to the paintball player who carries the cylinder on their person, and the gases are transferred to the marker via a length of hose. In either case it is beneficial to use as small a cylinder as is possible as the weight of the cylinder is an unwanted hindrance to the player as it is heavy and bulky. In order to have a small cylinder, and still be able to fire a high quantity of paintballs, it is essential that the paintball marker is as gas efficient as possible. The more efficient a marker is, the smaller the compressed gas tank can be. [0011] Therefore, it is envisioned that if this wasteful empty volume, located behind the paintball and, typically, inside the bolt, could be eliminated from the design of a paintball marker, it has the potential to significantly increase the efficiency of the marker, allowing more shots from a given cylinder size, or the use of smaller cylinders to be able to shoot the same number of shots. [0012] In view of the foregoing, there is a need to make a marker more efficient in its use of gas. There is also a need for a marker to use less gas for each paintball launch. There is a further need for a marker that requires smaller gas cylinders to provide operational gas. There is a need for a marker that has an improved bolt and valve mechanism that enables more paintballs to be launched from a given cylinder of gas than prior art markers. SUMMARY OF THE INVENTION [0013] An embodiment of the present invention preserves the advantages of prior art gas powered guns or markers. In addition, it provides new advantages not found in currently available gas powered guns or markers and overcomes many disadvantages of such currently available gas powered guns or markers. [0014] The proposed invention is a new bolt and air release valve mechanism for a paintball marker that uses significantly less gas per shot. The open gas chamber between the paintball and the air release mechanism is eliminated thereby requiring much less gas to be used for launching a given paintball. The construction of the bolt and gas release member is configured move the location of the seal between the bolt and the gas release member to right behind the paintball to be launched. Thus, only the launching gas to propel the paintball is needed and not the additional gas required to fill the chamber in the bolt directly behind the paintball. [0015] It is therefore an object of the embodiment to provide a bolt and valve mechanism that uses less gas. [0016] It is a further object of the embodiment to provide a marker with a bolt and valve system that uses less gas for each paintball launch than prior art markers. [0017] Another object of the embodiment to provide a marker that requires a smaller gas cylinder than prior art markers to launch the same number of paintballs. [0018] Yet another object of the present invention is to provide a marker that is more efficient than prior art markers due to use of less gas for each paintball launch. BRIEF DESCRIPTION OF THE DRAWINGS [0019] The novel features which are characteristic of the pneumatic launching assembly are set forth in the appended claims. However, the pneumatic launching assembly, together with further embodiments and attendant advantages, will be best understood by reference to the following detailed description taken in connection with the accompanying drawings in which: [0020] FIG. 1 is a cross-sectional view of a prior art marker with wasteful gas space between the projectile and the air release valve; [0021] FIG. 2 is a cross-sectional view of another example of a prior art marker with wasteful gas space between the projectile and the air release valve; [0022] FIG. 3 is a cross-sectional view of a marker with the bolt and valve mechanism of the present invention in a position for projectile loading; [0023] FIG. 4 is a cross-sectional view of the marker of FIG. 3 with the bolt and air release mechanism moving together toward a projectile launching position; [0024] FIG. 5 is a cross-sectional view of the marker of FIG. 3 with the bolt and air release mechanism in a position with the air release at the end of its travel; and [0025] FIG. 6 is a cross-sectional view of the marker of FIG. 3 with the air release at the end of its travel with the bolt moving forward to separate air release therefrom to release air into projectile for launch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0026] The improved bolt and valve mechanism of the present invention allows for a marker design that has the potential to have zero empty volume to fill between the gas release mechanism, namely between a gas release member and the bolt, and the back of the paintball. As a result, a marker equipped with the bolt and valve mechanism of the present uses less gas for operation than prior art markers. [0027] In accordance with the present invention, the improved bolt and valve mechanism carries the air release mechanism inside the bolt mechanism rather than at the end thereof as in the prior art. As a result, and as the bolt moves, the air release mechanism moves with it. Namely, the sealing connection of the bolt and the free end of the gas release member is directly behind the paintball. The seal and sealing poppet of the air release mechanism are both sited, and move together with, the bolt body. [0028] FIGS. 3-6 illustrate the operation and construction of the system of the present invention in detail. Turning first to FIG. 3 , a cross-sectional view of a paintball marker 100 that employs the improved bolt and valve mechanism of the present invention is shown. The marker includes an outer housing 102 with a sleeve 103 that is connected to a barrel 104 with a breech 106 disposed therebetween. Paintballs 110 are fed from, for example, a hopper (not shown) into the breech 106 via a feed tube. Uniquely, a bolt 112 and gas release member 114 are slidably disposed in the sleeve 103 in the housing 102 . The gas release member 114 and the bolt 112 provide a poppet-like valve construction, however, the chamber ( 28 , as seen in FIG. 1 ) between the point of sealing and the paintball 110 is preferably substantially removed or even completely removed to, thereby, eliminate the need to fill it with gas. Front chamber 109 is substantially smaller, such as several times smaller, than the gas firing chamber 124 . As above, this avoids use of extra gas for each firing cycle. It is even possible to further reduce the size of completely eliminate front chamber 109 to further reduce the amount of gas behind the paintball 110 before launch down to a minimal or insignificant amount. [0029] The gas release member 114 includes an elongated stem portion 114 a with a front sealing portion 114 b with an O-ring 116 positioned therearound. A centering 114 c pin is also provided on the front most portion 114 b of the gas release member 114 . The gas release member 114 is slidably received in the bolt 112 , which has a slot 112 a therethrough. It should be noted that the bolt 112 is shown with two portions that are threaded together to form the bolt structure. It should be understood that the bolt 112 may be of a unitary construction. The gas release member 114 includes a firing pin 120 that is fixed thereto. As a result, the extent of travel of the gas release member 114 relative to the bolt 112 is defined by the slot 112 a in the bolt 112 , as will be further discussed below. Therefore, the gas release member 114 actuates back and forth within the bolt 112 and is spring-biased, by a spring 122 , into a forward position so that the front most portion 114 b and centering pin 114 c of the gas release member 114 resides on a seat 112 b and with the O-ring sealing thereacross. A keyway 112 c is also preferably provided to receive centering pin 114 c . Thus, along with numerous other sealing surfaces, the chamber 124 behind the front most portion 114 b of the gas release member 114 is rendered airtight and is in condition for receipt of gas therein in preparation for paintball launch. [0030] It can also be seen in FIG. 3 that the bolt 112 and gas release member 114 , together, actuate back and forth within the sleeve 103 residing in housing 102 . Still further, the firing pin 120 , affixed to the gas release member 114 also serves to limit the amount of travel of the mated bolt 112 and gas release member 114 because the firing pin also is slidably positioned within a slot 103 a in the sleeve 103 inserted into housing 102 . In FIG. 3 , the firing pin 120 is located at the rear of the slot 103 a in the sleeve, which serves as a stop. [0031] In the paintball loading step seen in FIG. 3 , the bolt 112 and the gas release member 114 are both in their rearward most position. A newly loaded paintball 110 is delivered into the breech 106 and is positioned in front of the bolt 112 , preferably at a curved leading surface 112 e , and the system is prepared for launch. The chamber 124 is defined inside the bolt 112 and rearward of the sealing location at the O-ring 116 . In this position, the front portion 114 b of the air release member 114 at the head of the bolt 112 is sealed off so no air is being released yet from the firing chamber 124 within the bolt 112 and surrounding the stem portion 114 a of the gas release member 114 . At this point, the firing chamber 124 of gas is ready for release to push the paintball 110 forward through the barrel 104 . [0032] Turning now to FIG. 4 , a cross-sectional view of the paintball marker 100 of FIG. 3 is shown during the next step of moving the paintball 110 to a position in the barrel 104 in preparation for launch. The marker 100 has been fired and the launch cycle has been started. The bolt 112 and gas release member 114 are shown moving forward together, with the paintball 110 being pushed ahead of the bolt 112 towards the barrel 104 ready for launching. The firing chamber 124 remains full of gas as the gas release member 114 is still serving to seal off gas flow to behind the paintball 110 . Thus, a fully contained firing chamber 124 is travelling forward in a sealed condition along with the bolt 112 and gas release member 114 in unison. Thus, the bolt 112 and gas release member 114 , in FIG. 4 , travel together as a single unit with the firing pin 120 moving forward within the slot 103 a in the sleeve residing in the housing 102 . [0033] Now turning to FIG. 5 , the paintball 110 has been moved forward so that it is now loaded in the barrel 104 and the breech 106 is closed off from the feed of additional paintballs (not shown) and the paintball 110 is ready to be actually launched. At this point, the front most portion 114 b of the gas release member 114 and the O-ring 116 are still in contact with the seat 112 b of the bolt 112 to maintain the sealed integrity of the gas chamber 124 . It can be seen in FIG. 5 that the bolt 112 and the gas release member 114 are still travelling together. However, the firing pin 120 , fixed to the gas release member 114 , has reached its forward most limit and has contacted the front edge of longitudinal the slot 103 a in the sleeve 103 . [0034] As a result, the air release member 114 cannot travel any further forward. However, due to the further slidable engagement of the firing pin 120 relative the longitudinal slot 112 a in the bolt 112 , further forward travel of the bolt 112 is possible, which will result in the gas release member 114 separating from the bolt 112 thereby opening the seal and allowing the gas from the firing chamber 124 to be released directly behind the paintball 110 for launching. [0035] This separation of the bolt 112 and the gas release member 114 is shown in FIG. 6 , which illustrates the actual release of gas from chamber 124 and the subsequent launch of the paintball 110 . It can be seen that the front edge of the firing pin 120 remains in contact with the front edge of the longitudinal slot 103 a in the sleeve, serving as a stop, to prevent further forward travel of the gas release member 114 while the rear edge of the firing pin 120 remains in contact with the rear edge of the longitudinal slot 112 a in the bolt 112 . The use of the slots 112 a and 103 a and the firing pin 120 connected to the gas release member 114 , the actuating travel of the bolt 112 relative to the gas release member 114 and the actuating travel of both the bolt 112 and the gas release member 114 together can be controlled with precision. [0036] Still referring to FIG. 6 , the bolt 112 is shown in its forward most position. Because the gas release member 114 cannot move further in the forward direction, the bolt 112 continues on forward on its own to cause the aforementioned release of the seal of the front portion 114 b of the gas release member 114 with the seat 112 b at the front of the bolt 112 . As can be understood, once this seal is opened, the gas from the chamber 124 is free to exit forward through the front of the bolt 112 to supply gas directly behind the paintball 110 to launch it forward through the barrel 104 . [0037] It should be noted that the configuration of the bolt 112 and gas release member 114 are preferred embodiments of the present invention. It is possible to modify the mating configuration, such as the structure of the seat 112 b and the front portion 114 b of the gas release member 114 and the location and construction of the firing pin mechanism and still be within the scope of the present invention. [0038] The paintball marker 100 can then be configured to reset in preparation for launch in a number of different ways known in the prior art. For example, springs or pneumatics can be used to move the bolt 112 and gas release member 114 back to the condition see in FIG. 3 in preparation for receipt of a new paintball 110 . Movement of such bolts 112 and other components for marker reset are so well known in the art that they need not be discussed herein. [0039] In view of the foregoing, the construction of the present invention can result in a significant increase in marker efficiency due to the fact that there is little or no air lost in filling an empty volume between the back of the paintball 110 and gas release member 114 on every paintball launch. This is made possible by moving the sealing point to a position directly behind the paintball 110 . [0040] It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be covered by the appended claims.	The proposed invention is a new bolt and gas release valve mechanism for a projectile launching device, such as a paintball marker, that uses significantly less gas per shot than prior art devices. The open gas chamber between the projectile, such as a paintball, and the gas release mechanism is eliminated thereby requiring much less gas to be used for each launch of a given projectile. Thus, only the launching gas to propel the projectile is needed and not the additional gas required to fill the chamber in the bolt directly behind the projectile. This enables desirably smaller gas supply tanks to be used during use to launch the same number of projectiles. Also, with the present invention, more projectiles can be launched using the same gas supply tank.	5
CROSS REFERENCE TO RELATED APPLICATIONS This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/EP2005/002521, which has an international filing date of Mar. 10, 2005, and which claims priority to German patent application number GE102004013708.2 filed Mar. 17, 2004. FIELD OF INVENTION This invention provides a method for operating a power stage in a power electronics circuit for an electric motor. The invention also provides a supply unit for a driver circuit for an electric motor. BACKGROUND OF THE INVENTION Electrical driver units generally comprise an electric motor and a power electronics circuit. The power electronics circuit draws power from a supply system at a fixed frequency and voltage and converts this power to produce a rotating field in a motor. The speed and torque of the motor are regulated by the power electronics circuit. The power electronics circuit generally comprises a servo amplifier or, in an unregulated drive system, a frequency converter. The servo amplifier and the frequency converter are normally together called an inverter and are actuated by means of the driver circuit provided in the power electronics circuit. When electric drive units are being used, it is necessary for them to be immediately turned off and safely stopped in the event of faults or risks. That is to say that the motor must under no circumstances move on account of electrical actuation. Normally, this is done by turning off the power supply for the power electronics circuit, as is known, by way of example, from the document BIA Report May 2003 “Sichere Antriebssteuerung mit Frequenzumrichtern” [Safe drive control using frequency converters], ISBN 3-88383-645-1 or from the document Antriebstechnik 33 (1994), No. 10, “Vermeidung von unerwartetem Anlauf bei stromrichtergespeisten Antrieben” [Avoiding unexpected starting in inverter-powered drives], Erwin Zinken, BIA St Augustin. This allows the motor to be reliably stopped, since no further power is supplied to the motor. However, when it is started again the entire power electronics circuit needs to be turned on again, which takes a considerable amount of time. A further option is to isolate the motor from the power electronics circuit using an electromechanical switch, e.g. a contactor. However, the sudden switching can easily damage the power electronics circuit on account of overvoltages. In addition, the loading is also very high for the contactor, since high current levels need to be switched. A further solution for safely turning off the rotating field is to suppress the ignition pulse. Ignition pulses are equivalent to control signals generated by the driver circuit in the power electronics circuit, which actuates the power stage in the power electronics circuit. The power stage has six electronic switches which are controlled by means of control signals, so that the internal DC voltage is converted into a three-phase alternating current. The ignition pulse can be suppressed in various ways. It is usual—as known from the aforementioned document BIA Report May 2003—to interrupt the supply voltage at the driver circuit. The voltage is usually turned off by a relay in the event of a fault. Safe stopping through ignition pulse suppression, i.e. by not producing the control signals, leaves all the other components in the power electronics circuits in a full standby state. For the ongoing application, it is thus possible to put the electrical drive system into the safe state and to activate it again without this being noticed. Delays when the driver circuit is turned on again do not arise in essence. The switching of the supply voltage at the driver circuit has to date been effected by a mechanical relay, which is subject to wear. Such a mechanical switching relay does not allow the power electronics circuit to be designed for “single-fault safety”. “Single-fault safety” means that if a fault occurs in one of the safety-related components used the actuation of the motor is stopped immediately. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for operating a power stage in a power electronics circuit for an electric motor which is designed for “single-fault safety” in particular. It is also an object of the present invention to provide a supply unit for a driver circuit, particularly for actuating a motor, which is designed for “single-fault safety”. A first aspect of the present invention provides a method for operating a supply unit for a driver circuit, particularly in a power electronics circuit for an electric motor. A control current is switched by an inductive converter using a first and a second switch on the basis of a first control signal and a second control signal in order to generate a power supply for the driver circuit. Turning off the first and second switches allows a free-wheeling current to flow through a first or a second free-wheeling current path. Actuating the power stage involves first of all turning on the first and second switches on the basis of the first and second control signals and then, e.g. on the basis of an actuation value, turning off the first switch in a turnoff operation using the first control signal. The turnoff operation prompts measurement of the free-wheeling current through the first free-wheeling current path. The second switch is then switched, or not, using the second control signal on the basis of the measured first freewheeling current. The inventive method has the advantage that in a supply unit a switching operation taking place in a normal mode involves the operation of the first switch being checked by using the measured free-wheeling current to identify whether the first switch has actually interrupted the current path on the basis of the first control signal and is thus operating correctly. Since generating the power supply requires both switches to be turned on and off constantly, essentially at the same time, the generation of the power supply can be interrupted immediately by preventing one of the switches from switching. In line with a first alternative, the second switch is prevented from being turned off if measurement of the free-wheeling current through the first free-wheeling path detects a fault. Since, when a fault is identified in this manner, the turn-off operation for the first switch has not actually turned said switch off, the circuit thus remains closed via the inductive converter. As a result of the switching of the second switch being prevented, however, no further switching operation takes place, which means that no power can be transmitted by the inductive converter. In line with a further alternative, the first and second switches can be prevented from being turned on again if measurement of the free-wheeling current through the first free-wheeling current path detects a fault. In this case, the second switch is turned off after the fault is identified. This has the advantage over the first alternative that a continuous direct current cannot flow through the inductive converter, which current can sometimes result in destruction thereof. Provision can be made for a further switching operation to involve first of all turning on the first and second switches again on the basis of the first and second control signals and then turning off the second switch in a further turn-off operation using the second control signal. As a result, the free-wheeling current through the second free-wheeling current path is measured and the first switch is switched using the first control signal on the basis of the measured free-wheeling current through the second free-wheeling current path. This also allows the operation of the second switch to be checked. In particular, one of the two switches can be checked alternately in each switching cycle to determine whether it is operating correctly, i.e. to determine whether it is being turned off correctly. If one of the two switches does not interrupt the respective current path correctly, the subsequent check on the switching behavior prevents further switching of the respective other switch, which means that no further voltage or current change takes place on the inductive converter in order to stop further power transmission and hence the power supply immediately. Actuation of the power stage in the power electronics circuit is stopped such that no power is provided for generating a rotating field for a downstream electric motor which needs to be stopped. If measurement of the free-wheeling current through the second free-wheeling current path detects a fault, the first and second switches can firstly be prevented from being turned on again and/or the first switch can be prevented from being turned off, in a similar manner to the procedure when checking the first free-wheeling current path. Provision may be made for the first and/or the second control signal to be generated using a periodic signal. The periodic signal can be blocked for generating the first and/or the second control signal if measurement of the free-wheeling current through the first and/or the second free-wheeling current path detects a fault. Blocking the periodic signal required for generating the control signals is one way of immediately stopping the switching operations for the first and second switches. A further aspect of the present invention provides a supply unit for a driver circuit for a power stage, particularly in a power electronics circuit for an electric motor. The driver circuit has an inductive converter which is connected in series with a first and a second switch in order to provide a power supply by switching the switches. The first and second switches can be actuated by a first and a second signal, respectively. The power supply can be produced in the inductive converter by turning on and off the first and second switches. The first switch has a first free-wheeling current path connected to it in order to accept a freewheeling current in a turn-off operation for the first switch. The second switch is connected to a second freewheeling current path in order to accept a free-wheeling current in a turn-off operation for the second switch. The driver circuit has a control device in order, in a turn-on operation, to turn on the first and second switches on the basis of the first and second control signals and in order, in a turn-off operation, first of all to turn off the first switch and to measure a freewheeling current through the first free-wheeling current path, and in order to switch the second switch on the basis of the measured free-wheeling current path. The supply unit based on the invention is used for operating a driver circuit for a power stage with a power supply which is produced by turning on and off a supply voltage on an inductive converter. The turning-on and turning-off are effected using two switches which need to be switched essentially at the same time. The control device first of all turns on the two switches at the same time and then, e.g. on the basis of an actuation value, turns off the first switch. If the first switch is faulty and does not interrupt the current path through the inductive converter, this is detected by the measurement of the free-wheeling current through the first freewheeling current path, and the second switch is prevented from being switched again. If it is detected that the first circuit is switched correctly, the second switch is likewise turned off, so that the period of time between turning off the first switch and turning off the second switch is as short as possible. The first free-wheeling current path can have a first current sensor and/or a first free-wheeling diode. The second free-wheeling current path can have a second current sensor and/or a second free-wheeling diode. The control device can be designed so that, in a further turn-off operation, it first of all turns off the second switch and measures a free-wheeling current through the second free-wheeling current path in order to switch the first switch on the basis of the measured free-wheeling current. The effect which can be achieved by this is that first the first and then the second switch are alternately turned off in each turn-on/turn-off operation so as to check the operation of the first and second switches in succession. In line with a further embodiment, the supply unit comprises a first control circuit and a second control circuit, which is separate from the latter, with the first control circuit controlling the switching of the first switch and measuring the current through the first free-wheeling current path. The second control circuit accordingly controls the switching of the second switch and measures the current through the second free-wheeling current path. The first control circuit and the second control circuit are coupled to one another such that the first control circuit generates the first control signal on the basis of a second Active signal on line 25 which is applied by the second control circuit, and the second control circuit conversely generates the second control signal on the basis of a first Active signal on line 24 which is applied by the first control circuit. This makes it possible to achieve single-fault safety, which interrupts the generation of control signals and hence the provision of the power supply as soon as a fault occurs in one of the switches, in one of the freewheeling paths or in one of the control circuits. As soon as the control circuit identifies the fault in the respective associated switch, it checks the operability of the switch. By virtue of the control circuit generating the Active signal which is required by the respective other control circuit in order to actuate the associated switch, provision of the power supply is interrupted even if one of the control circuits fails. This means that the driver circuit based on the invention has “single-fault safety”, since provision of the power supply is interrupted immediately when a fault occurs in one of the components. So that the first and second Active signals on lines 24 , 25 cannot be generated incorrectly, said signals are provided as a periodic signal or as a signal sequence from the respective control circuit, so that in the event of a fault the Active signals on lines 24 , 25 continue to be produced. The periodic signal or the signal sequence has the advantage that in the event of a fault in the respective control circuit which would result in a permanent state of the corresponding Active signal this state does not result in the respective control signal continuing to be generated in the duplicate other control circuit. Preferably, the inductive converter is in the form of a transformer. In line with one embodiment of the invention, the control device is designed to generate the first and/or the second control signal using a provided clock signal. If a fault occurs, the clock signal can be interrupted, which means that generation of the first and second control signals is interrupted. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are explained in more detail below with reference to the appended drawings, in which: FIG. 1 shows a block diagram to illustrate a drive system; FIG. 2 shows a block diagram of the inventive driver circuit; and FIG. 3 shows a signal flowchart to illustrate the actuation of the switches in the driver circuit. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a block diagram of the actuation of an electric motor in a drive system. A control system 1 generates actuation values, with an electric motor 2 being intended to be actuated on the basis of the actuation values. The electric motor 2 is usually actuated using a power electronics circuit 3 which comprises a power stage 4 and a driver circuit 5 . In the example shown, the power stage 4 generates three phase currents and for this purpose typically has 6 electronic switches (not shown) which are actuated by means of respective switching signals from driver circuit 5 . The electric motor 2 is preferably in the form of a synchronous or asynchronous motor, particularly in the form of an electric motor which can be operated using an electrical rotating field and has no separate commutation. The power stage 4 is used to provide the rotating field at the necessary current level for operating the electric motor 2 . The switching signals which are used to actuate the power stage 4 are provided by the driver circuit 5 . In some fields of application, it is necessary for the electric motor 3 to be stopped immediately when a fault occurs so that the electric motor 2 does not continue to run uncontrolled. This is done by virtue of the driver circuit 5 in the power electronics circuit 3 immediately interrupting the generation of the respective switching signal as soon as a fault has been identified. To generate the rotating field for the electric motor 2 , a particular sequence of switching signals is required. If the driver circuit stops these switching signals, it is not possible to produce the rotating field. This allows the electric motor 2 to be stopped. Generation of the switching signals in the driver circuit 5 is interrupted, in particular, by interrupting the power supply to the driver circuit 5 . The power supply is provided by a supply unit 6 which is connected to the driver circuit 5 . FIG. 2 shows a circuit diagram of an inventive supply unit 6 for a driver circuit 5 . The power supply in the form of a supply voltage is provided for the driver circuit 5 , which generates switching signals which are forwarded to the electronic switches in the power stage 4 . The switching signals are DC isolated and are in a voltage range which is appropriate for an electronic switch in a downstream power stage. Typically, the gate input of a power field effect transistor is inbuilt in the power stage. The switching signal is essentially a pulse-width-modulated signal which transmits on and off states to the power stage. The power stage (not shown) then turns on or off a coil winding in the electric motor on the basis of the switching signal. The supply unit 6 which is shown in FIG. 2 generates a supply voltage as a power supply, said supply voltage being produced in a secondary coil 12 on the basis of a signal being switched on a primary coil 10 in a transformer 11 . Since turning on and off the flow of current through the primary coil produces positive and negative voltages in the secondary coil 12 , this resultant voltage signal is rectified by means of a rectifier diode 13 and is preferably smoothed by a capacitor (not shown), so that essentially a positive voltage is applied to the driver circuit 5 . The primary coil 10 is connected in series with a first switch 14 and a second switch 15 between a high supply voltage potential VDD and a low supply voltage potential, preferably a ground potential GND. The first and/or the second switch 14 , 15 are preferably in the form of field effect transistors, these each being able to be actuated by means of a control signal via an appropriate gate connection. To switch the transformer 11 , the first and second switches 14 , 15 are usually turned on and off at the same time, so that the switching operations in the primary coil 10 induce the corresponding voltage signal in the secondary coil 12 of the transformer 11 . Particularly in the turn-off operation, the inductance of the primary coil 10 produces a free-wheeling current which is in the opposite direction to the flow of current when the primary coil 10 is in the turned-on state. So that this current does not result in harmful overvoltages on the field effect transistors and other components of the driver circuit, each of the switches 14 , 15 is provided with a free-wheeling current path 16 , 17 . The first switch 14 is arranged between the high supply potential VDD and a first connection of the primary coil 10 . The first connection of the primary coil 10 is connected via the first free-wheeling current path 16 to the ground potential, so that a free-wheeling current when the first switch is turned off can drain to the ground potential GND. The second switch 15 is arranged between a second connection of the primary coil 10 and the ground potential GND. The second connection of the primary coil 10 is likewise connected via a second freewheeling current path 17 to the high supply voltage potential VDD. So that turning on the switches does not produce a short between the high supply potential VDD and the ground potential GND, the first free-wheeling current path 16 contains a first free-wheeling diode 18 and the second free-wheeling current path 17 contains a second freewheeling diode 19 such that a voltage which is negative with respect to the ground potential and which is applied to the first connection of the primary coil 10 is drained via the first free-wheeling current path 16 , and a voltage which is higher than the high supply potential VDD and which is applied to the second connection of the primary coil 10 is drained via the second free-wheeling current path 17 , since the respective free-wheeling diode 18 , 19 becomes conductive in this direction. The first free-wheeling current path 16 has a first current sensor 20 , and the second free-wheeling current path 17 has a second current sensor 21 , in order to measure the respective free-wheeling currents through the free-wheeling current paths 16 , 17 . The current sensors 20 , 21 may be designed, by way of example, using a measuring resistor, e.g. a shunt, or may have a magnetic field current sensor in which the resistor in the respective free-wheeling current path is not affected by a measuring resistor. To measure a free-wheeling current, it is also possible to detect the free-wheeling current by measuring the current through the corresponding switch. A first control circuit 22 and a second control circuit 23 are provided for generating the first and second control signals on lines 27 , 28 for the switches 14 , 15 . The first control circuit 22 is connected to the first current sensor 20 , so that a measured free-wheeling current in the first free-wheeling current path 16 is provided in the first control circuit 22 . The first control circuit 22 is connected to a control input of the first switch 14 , particularly to the gate connection of the first field effect transistor. The second control circuit 23 is connected to the second current sensor 21 , so that the measured free-wheeling current in the second free-wheeling current path 17 is available in the second control circuit 23 . The second control circuit 23 is connected to a control input of the second switch 15 , i.e. to the gate connection of the second field effect transistor. The first control circuit 22 is connected to the second control circuit 23 via a first Active signal line 24 in order to transmit a first Active signal to the second control circuit 23 . A second Active signal line 25 is provided, so that the second control circuit 23 can transmit a second Active signal to the first control circuit 22 . The control circuits 22 , 23 receive, via a signal line 26 , an externally prescribed enable signal which permits or prevents actuation of the electric motor 2 . In addition, each of the control circuits 22 , 23 has an input for a clock signal CLK. The control circuits are synchronized to this clock. The text below describes the mode of operation of the first control circuit 22 with regard to the first switch 14 and the first free-wheeling current path 16 , the second control circuit 23 operating in essentially similar fashion with regard to the second switch 15 and the second free-wheeling current path 17 . The first and second control circuits 22 , 23 receive the enable value via the data line 26 and, at the start of the period duration, generate a respective turn-on signal as a first control signal on line 27 or as a second control signal on line 28 , which is supplied to the first switch 14 or the second switch 15 , respectively, e.g. a high level. The respective turn-on signal turns on the switches 14 and 15 , so that the high supply potential VDD is connected to the first connection of the primary coil 10 and the low supply potential GND is connected to the second connection of the primary coil 10 . When a turned-on period has elapsed, the first control signal on line 27 is switched such that the first switch 14 is turned off, e.g. by changing to a low level. The turnoff operation produces a free-wheeling voltage on the primary coil 10 of the transformer 11 , said voltage being reduced via the first free-wheeling current path 16 . The free-wheeling current in the first free-wheeling current path 16 is measured using the first current sensor 20 , and the measured value is made available to the first control circuit 22 . The latter compares the measured current value with a threshold current value which is chosen such that it is possible to detect that a significant free-wheeling current is flowing. This allows the switching behavior of the first switch 14 to be checked. This is because if the first switch 14 is not interrupted on the basis of the first control signal on line 27 , the first current path 16 through the primary coil 10 is not interrupted and a free-wheeling voltage which would need to be reduced via the first free-wheeling current path 16 does not arise. This is detected as a fault in the first control circuit 22 , and further generation of the first control signal on line 27 to turn on the first switch 14 is stopped. If a free-wheeling current in the first free-wheeling current path 16 is measured which exceeds the threshold current value, the first control circuit 22 generates a first Active signal on line 24 , as a result of which the first Active signal is transmitted to the second control circuit 23 . When the first Active signal is received, the second control circuit 23 immediately turns off the second switch 15 , so that for the entire period duration of the second control signal on line 28 only a short time delay arises between turning off the first switch 14 and turning off the second switch 15 , and this time delay has no significant effects on the generation of the switching signal. The first and second control circuits 22 , 23 operate essentially in sync, which means that it is advantageous if the same clock signal CLK is applied to both control circuits 22 , 23 . The two control circuits 22 , 23 are tuned to one another such that during a clock cycle only one of the two control circuits ever generates the control signal for turning off the respective switch 14 , 15 independently without receiving the Active signal beforehand. Preferably, the two control circuits 22 , 23 operate out of sync with regard to the turn-off signal, and particularly in a first clock cycle the first control circuit 22 generates the first control signal on line 27 for turning off the first switch 14 independently and the second control circuit 23 makes the second control signal on line 28 for turning off the second switch 15 dependent on the first switch 14 having been turned off. In a second clock cycle, the second control circuit 23 then generates the control signal on line 28 for turning off the second switch 15 independently of the first Active signal on line 24 , and the first control circuit 22 on the basis of the second Active signal on line 25 generated by the second control circuit 23 when the second switch 15 is successfully turned off. The respective Active signal indicates to the respective control circuit 22 , 23 that the control signal for turning off the respective switch 14 , 15 now needs to be generated. That the respective switch has been turned off is preferably indicated by a suitable edge of the Active signal, since this edge needs to be generated actively by the respective control circuit. It is also possible for faults which occur in one of the control circuits to result in immediate interruption of the generation of the switching signal, since the Active signal can be produced only by a correctly operating control circuit 22 , 23 . This provides the presented supply unit 6 with “single-fault safety”, i.e. when a fault occurs in one of the components used the generation of the switching signal is immediately interrupted, so that the rotating field is no longer produced to actuate the electric motor 2 . The proposed supply unit is thus in a form such that faults when one of the switches 14 , 15 is turned off immediately result in an appropriate switching signal no longer being generated. Since the relevant control circuit 22 , 23 may also have faults and then might no longer identify a relevant fault when the respective switch is switched, the control circuit must actively generate an Active signal when the switch connected to it is detected to have been turned off. This signal would not be generated in a faulty control circuit, which means that the respective other control circuit does not generate a turn-off signal. In the subsequent clock cycle too, no control signals would be generated which result in one of the switches 14 , 15 being switched. Hence, by way of example, a fault in the first switch 14 which involves the first switch 14 no longer switching from its turned-on state to its turned-off state results in the second switch 15 no longer being turned off either, since the Active signal required by the second control device 23 would no longer be generated by the first control circuit 22 . The current path through the primary coil 10 is thus maintained. Since there is no longer a change of current in the primary coil 10 , no power is transmitted to the secondary coil 12 either, which means that the supply voltage is turned off. Alternatively, provision may also be made for the occurrence of a fault which is identified by one of the control circuits and is indicated to the others by the absence of the correct Active signal to result in the control circuit generating a control signal to turn off the switch which is connected to it, in order to interrupt the current path through the primary coil 10 in every case, since otherwise a very high direct current would flow through the primary coil 10 which might destroy it. However, this results in a further switching operation in which power briefly continues to be transmitted to the secondary coil 12 and thus produces a further edge in the switching signal, so that the turnoff operation for the rotating field for actuating the electric motor 2 would continue to be produced. Depending on the application in which the electric motor 2 is being operated, this is a negligibly short period in the range of a few μsec, however. Similarly, faults in one of the free-wheeling diodes 18 , 19 can be identified. If one of the free-wheeling diodes 18 , 19 starts to conduct in the reverse direction, there is a short between the high supply potential VDD and the ground potential GND, and the safe state is reached. The circuit would then not operate. If the diode in question starts not to conduct in the forward direction, however, this failure does not prevent operation but is relevant to safety if a transistor with a short fails. The fault that the respective free-wheeling diode 18 , 19 starts not to conduct in the forward direction results in the current sensor 20 , 21 measuring no free-wheeling current, which means that the respective control circuit does not generate an Active signal, since it cannot detect that the respective switch 14 , 15 has turned off. Hence, a faulty diode results either in a short being produced in the circuit which stops the electric motor or in the generation of the control signal in question being prevented. A significant advantage of such a supply unit is that diagnostic intervals are just one cycle of the clock signal CLK, which means that they can be carried out at short intervals of time of 50 μsec, for example. In addition, a superordinate control system (not shown) may be connected to the control units 22 and 23 . If one were no longer to operate correctly, the superordinate control system can block the enable signal on signal line 26 , so that the control circuits 22 , 23 generate no more control signals. FIG. 3 shows a signal diagram to illustrate the profiles of the clock signal CLK and the first and second control signals ST 1 , ST 2 . It can be seen that the first and second control circuits 22 , 23 indicate that the respective switch has been turned on upon the rising edge of the clock signal by means of a likewise rising edge of the control signals ST 1 , ST 2 . For a particular period, the two control signals ST 1 , ST 2 remain at the high levels. It can be seen that the first control signal ST 1 turns off the first switch 14 with a rising edge. A suitable Active signal is then generated in the control circuit 22 if the switching operation was successful and no other fault has occurred. This signal is transmitted to the second control circuit 23 , which generates the falling edge for the second control signal ST 2 in order to turn off the second switch 15 . Up to the next rising edge of the clock signal CLK, the control signals remain at a low level. Upon the next rising edge of the clock signal CLK, the two control signals ST 1 , ST 2 change to a high level, with the second control circuit 23 now generating a falling edge of the second control signal ST 2 . The falling edge of the second control signal ST 2 turns off the second switch 15 , with an Active signal being generated if the second switch 15 has been turned off and no further fault has occurred. The Active signal then likewise turns off the first switch 14 , with a negligible time delay, in line with a falling edge of the first control signal ST 1 . It is thus possible for the operation of the switches 14 , 15 or of the components in the respective free-wheeling current path to be checked alternately, with generation of the control signals ST 1 , ST 2 being stopped immediately if a fault is identified.	A power supply and method of operating the same. The method includes the steps of: operating first and second switches to an “On” position; operating said first switch to a “Off” position, causing a flow of a first free-wheeling current through a first free-wheeling current path; measuring a value of said free-wheeling current; controlling the switching of said second switch responsive to said value of said free-wheeling current; and regulating power from said power supply unit. The power supply includes: an inductive converter; a first free-wheeling current path comprising: a first switch connected in series with said inductive converter and a first means for measuring a first free-wheeling current flowing through said first free-wheeling current path; and a second free-wheeling current path comprising: a second switch connected in series with said inductive converter and a second means for measuring a second free-wheeling current flowing through said second free-wheeling current path.	7
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. Ser. No. 11/942,231, filed Nov. 19, 2007, which is currently pending. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable. APPENDIX Not Applicable. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to pet grooming tools and, more particularly, to toothed pet grooming tools of the type used to remove loose fur (i.e., fur that is not attached to the skin) from the coat of a pet. 2. Related Art Various types of pet grooming tools have been developed for the specific purpose of removing loose fur from the coats of pets. One of the most successful types of such grooming tools is described in U.S. Pat. Nos. 7,222,588, 7,077,076, and 6,782,846 and comprises a plurality of teeth arranged in a row. While such tools are effective in removing loose fur from pets, fur may become wedged or lodged between the gaps formed between the teeth of such tools and removing the such fur from the pet grooming tool can, in some cases, be somewhat time consuming. Typically, when fur becomes wedged in such a tool, the person using the tool simply closes his or her hand over the teeth and then pulls the fur out of the gaps. While this is a relatively simple action, it can be cumbersome when a person is using one hand to hold his or pet in place and therefore doesn't have a free hand. Additionally, some people find touching loose fur unpleasant. SUMMARY OF THE INVENTION The methods and pet grooming tools of the present invention improve the usability of pet grooming tools by providing a pet grooming tool with a fur ejector portion that is at least partially movable relative to the teeth of a pet grooming tool and can be manually moved into engagement with fur that is wedged between the teeth. The engagement of the fur ejector portion with the wedged fur forces the fur from the gaps between the teeth. Preferably the fur ejector portion can be manually moved by the same hand a person uses to support and hold the grooming tool. In one aspect of the invention, a pet grooming tool comprises a toothed portion and a fur ejector portion. The toothed portion comprises a plurality of teeth arranged in a row and a plurality of edge segments. Gaps lie between each adjacent pair of the teeth. The edge segments of the toothed portion are adapted to engage loose fur in a pet's coat as such loose fur extends through the gaps in a manner removing the loose fur from the pet's coat. The fur ejector portion comprises an edge that is movable between a first position and a second position relative to the toothed portion. The edge of the fur ejector portion is biased from the second position toward the first position such that an external force is required to move the edge of the fur ejector portion from the first position to the second position. The fur ejector portion is configured and adapted to permit fur to pass through the gaps of the toothed portion when the edge of the fur ejector portion is in the first position. The edge of the fur ejector portion is adapted to slidably contact the teeth of the toothed portion and to contact fur passing through the gaps of the toothed portion in a manner forcing fur from the gaps of the toothed portion as the fur ejector portion moves away from the first position toward the second position. In another aspect of the invention, a method of removing loose fur from a pet comprises a step of providing a pet grooming tool. The pet grooming tool comprises a toothed portion, a handle portion, and a fur ejector portion. The toothed portion comprises a plurality of teeth arranged in at least one row and a plurality of edge segments. A gap exists between each adjacent pair of the teeth. The fur ejector portion comprises an edge which is movable between a first position and a second position relative to the toothed portion. The method further comprises a step of moving the teeth of the toothed portion relative to a pet's coat by applying an external force to the handle portion while the fur ejector portion is in the first position. The movement causes a portion of loose fur of the pet's coat to pass into the gaps between the teeth of the toothed portion and causes the edge segments of the toothed portion to contact the portion of loose fur in a manner removing the portion of loose fur from the pet's coat. Still further, the method comprises a step off applying an external force to the pet grooming tool in a manner moving the edge of the fur ejector portion away from the first position toward the second position. The movement of the edge of the fur ejector portion away from the first position toward the second position causes the edge of the fur ejector portion to contact fur passing through the gaps of the toothed portion in a manner forcing such fur from the gaps of the toothed portion. In yet another aspect of the invention, a method of modifying a pet grooming tool comprises a step of providing a pet grooming tool. The pet grooming tool comprises a handle portion, a toothed portion, and a first screw. The toothed portion comprises a plurality of teeth. A gap exists between each adjacent pair of the teeth. The handle portion is in contact with the toothed portion and is removably attached thereto via at least the first screw. The method further comprises a step of attaching a fur ejector portion to the pet grooming tool by removing the first screw from the pet grooming tool, sandwiching the fur ejector portion between the handle portion and the toothed portion, and securing the fur ejector portion to the handle portion and to the toothed portion via at least a second screw. The fur ejector portion comprises an edge which is movable between a first position and a second position relative to the toothed portion when attached thereto. The fur ejector portion is configured and adapted to permit fur to pass through the gaps of the toothed portion when the edge of the fur ejector portion is in the first position. The edge of the fur ejector portion is adapted to engage fur passing through the gaps of the toothed portion in a manner forcing fur from the gaps of the toothed portion as the fur ejector portion moves toward the second position. Further features and advantages of the present invention, as well as the operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a perspective exploded assembly view of a pet grooming tool in accordance with the invention. FIG. 2 illustrates another perspective exploded assembly view of the tool shown in FIG. 1 . FIG. 3 illustrates a right side elevation view of tool shown FIGS. 1 and 2 . FIG. 4 illustrates a front elevation view of the toothed portion of the tool shown in FIGS. 1-3 . FIG. 5 illustrates a cross-sectional view of the toothed portion of the tool shown in FIGS. 1-3 , taken about the line 5 - 5 shown in FIG. 4 . FIG. 6 illustrates a cross-sectional view of the tool shown in FIGS. 1-3 , taken about the line 6 - 6 shown in FIG. 3 , and is shown with the edge of the fur ejector portion in the first position. FIG. 7 illustrates a cross-sectional view similar to FIG. 6 , but is shown with the edge of the fur ejector portion in the second position. FIG. 8 illustrates a perspective exploded assembly view of the pet grooming tool shown in FIGS. 1-3 , with the fur ejecting portion removed therefrom. FIG. 9 illustrates a perspective exploded assembly view of an alternative embodiment of a fur ejector portion of a pet grooming tool in accordance with the invention. FIG. 10 illustrates another perspective exploded assembly view of the fur ejector portion shown in FIG. 9 . FIG. 11 illustrates a perspective assembly view of the fur ejector portion shown in FIGS. 9 and 10 , with the edge of the fur ejector portion in the first position. FIG. 12 illustrates a perspective assembly view of the fur ejector portion shown in FIGS. 9-11 , with the edge of the fur ejector portion in the second position. Reference numerals in the written specification and in the drawing figures indicate corresponding items or steps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a pet grooming tool in accordance with the invention is shown in FIGS. 1-3 . The pet grooming tool 20 comprises a handle portion 22 , a toothed portion 24 , and a fur ejector portion 26 . Preferably, but not necessarily, the handle portion 22 , toothed portion 24 , and fur ejector portion 26 are formed as individual parts that are separable from each other. The handle portion 22 is configured to be held in one hand and is preferably elongate about a longitudinal axis. Preferably, the handle portion 22 is formed primarily of a relatively rigid plastic and has a softer rubbery grip portion. The handle portion 22 also preferably comprises a bearing surface 28 at one of its longitudinal ends. Two threaded holes 30 extend into the handle portion 22 from the bearing surface 28 . Preferably the threaded holes 30 are formed by threaded metal inserts. The toothed portion 24 of the pet grooming tool 20 is preferably formed of metal and comprises a plurality of teeth 32 . The teeth 32 preferably form a straight row. Preferably, the toothed portion 24 comprises a main body 34 having opposite forward facing 36 a rearward facing 38 surfaces. The forward facing 36 and rearward facing 38 surfaces are preferably parallel planar surfaces. The teeth 32 preferably extend from a front surface 40 to a back surface 42 . The front surface 40 preferably tapers toward the back surface 42 as said surfaces extend toward the tips 44 of the teeth 32 . Preferably the sides 46 of the teeth 32 intersect the back surface 42 in a manner forming a plurality of edge segments 48 . The edge segments 48 formed by the sides 46 of the teeth 32 have an angle of approximately ninety degrees. Forward facing surface segments 50 extend between the teeth 32 and intersect the back surface 42 in manner forming additional edge segments 48 . The edge segments 48 formed by the forward facing surface segments 50 are preferably significantly acute (≈40 degrees or less). The toothed portion 24 also preferably comprises a pair of through holes 52 that extend through its main body 34 . The fur ejector portion 26 preferably comprises a fixed portion 54 , a movable portion 56 , and a biasing portion 58 that are preferably formed together as a monolithic piece of homogeneous plastic. The fixed portion 54 of the fur ejector portion 26 preferably comprises a pair of through holes 60 that extend through the thickness of the fur ejector portion. The fixed portion 54 also comprises a plurality of guide surfaces 62 . The movable portion 56 has a thickness that is slightly less than that of the fixed portion 54 and comprises a front edge 64 that is preferably linear and oriented perpendicular to the guide surfaces 62 of the fixed portion 54 . The movable portion 56 also preferably comprises a plurality of guide surfaces 65 . The biasing portion 58 preferably comprises a pair of resilient bridges 66 that connect the movable portion 56 to the fixed portion 54 . The resilient bridges 66 are relatively slim and nonlinear such that they can flex relatively easily without fracturing or fatiguing. Preferably, part of the movable portion 56 of the fur ejector portion 22 forms an actuation button 68 . The fur ejector portion 26 of the pet grooming tool 20 also preferably comprises a fur guard 70 , which is preferably a piece of plastic sheet having two through holes 72 . The pet grooming tool 20 described above also preferably comprises a trim cap 74 and two screws 76 . The trim cap 72 is preferably a piece of plastic having a recess 78 that is dimensioned to receive the main body 34 of the toothed portion 24 of the pet grooming tool 20 . The trim cap 72 also has two countersunk through holes 80 . The pet grooming tool 20 is assembled by placing the fur guard 70 against the bearing surface 28 of the handle portion 22 , with the through holes 72 of the fur guard 70 aligned with the threaded holes 30 of the handle portion. The fixed portion 54 of the fur ejector portion 26 is then placed against the fur guard 70 with its through holes 60 also aligned with the threaded holes 30 of the handle portion 22 . Similarly, the toothed portion 24 of the pet grooming tool 20 is placed against the fur ejector portion 26 with its through holes 52 aligned with the threaded holes 30 of the handle portion 22 . Additionally, the trim cap 74 is placed against the toothed portion 24 with the main body 34 of the tooth portion positioned in the recess 78 of the trim cap and the countersunk through holes 80 of the trim cap aligned with the threaded holes 30 of the handle portion 22 . The screws 76 are then aligned with the threaded holes 30 of the handle portion 22 and are threaded thereinto, thereby clamping the components of the pet grooming tool 20 to one another. As assembled, the trim cap 74 conceals the main body 34 of the toothed portion 24 , thereby improving the aesthetics of the pet grooming tool 20 . Additionally, the fur guard 70 prevents fur from becoming lodged between the movable portion 56 and the fixed portion 54 of the fur ejector portion 26 , where it could otherwise interfere with the proper operation of the fur ejector portion and make the pet grooming tool 20 difficult to clean. In use, the teeth 32 of the toothed portion 24 of the pet grooming tool 20 are preferably pulled through the coat of a furry pet by grasping the handle portion 22 and applying a force thereto. As the teeth 32 of the toothed portion 24 is pulled through the pet's coat, the front surface 40 of the toothed portion trails the back surface 42 . During this process, the edge segments 48 of the toothed portion 24 of the pet grooming tool 20 grab loose fur within the pet's coat and force said loose fur from the coat. This effectively removes loose fur from the pet's coat. However, some of loose fur may become lodged in the gaps between the teeth 32 of the toothed portion 24 . To remove the lodged fur, the person using the pet grooming tool 20 presses his or her thumb against the actuation button 68 of the fur ejector portion 26 , which is otherwise biased by the biasing portion 58 in the first position shown in FIG. 6 . The resulting force on the fur ejector portion 26 causes the resilient bridges 66 of the biasing portion 58 of the fur ejector portion to bend and expand such that the movable portion 56 moves toward the tips 44 of the teeth 32 of the toothed portion 24 as shown in FIG. 7 (the second position). During such movement, the edge 64 of the movable portion 56 of the fur ejector portion 26 slidably moves against the back surface 42 of the toothed portion 24 of the pet grooming tool 20 and against the edge segments 48 . As such any fur that is lodged in the gaps between the teeth 32 of the toothed portion 24 of the pet grooming tool 20 is forced toward the tips 44 of the teeth and is thereby ejected from the pet grooming tool. Once released, the resiliency of the biasing portion 58 causes the resilient bridges 66 to return to their undeflected configuration, which causes the movable portion 56 of the fur ejector portion 26 to return to its first position relative to the toothed portion 24 of the pet grooming tool 20 . It should be appreciated that, because the fixed portion 54 of the fur ejector portion 26 is thicker than the movable portion 56 of the fur ejector portion, the movable portion is not clamped by the screws 76 . It should also be appreciated that the guide surfaces 62 of the fixed portion 54 of the fur ejector portion 26 slidably engage against the guide surfaces 65 of the movable portion 56 of the fur ejector portion, thereby controlling the direction in which the movable portion moves relative to the toothed portion 24 of the pet grooming tool 20 when the actuation button 68 is pressed. The fur ejector portion 26 of the pet grooming tool 20 described above is configured and adapted to be removed from the pet grooming tool. This is done by removing the screws 76 from the pet grooming tool 20 and then removing the fur ejector portion 26 , including the fur guard 70 . The rearward facing surface 38 of the toothed portion 24 of the pet grooming tool 20 can then be placed directly against the bearing surface 28 of the handle portion 22 . A second set of screws 82 , which are slightly shorter than the screws described above, can then be used to secure the remaining components together, as shown in FIG. 9 . Similarly, this process can be reversed to add the fur ejector portion 26 to a similar pet grooming tool that initially lacks a fur ejector portion. An alternative embodiment of a fur ejector portion is shown in FIGS. 9-12 . This alternative fur ejector portion 100 is interchangeable with the fur ejector portion 26 described above and preferably comprises separate movable 102 and fixed 104 portions and a biasing portion that is in the form of a standard compression coil-spring 106 . The fixed 102 and movable 104 portions are configured to interlocked with each other when they are sandwiched between the handle portion and the toothed portion of a pet grooming tool, albeit the movable portion can reciprocate between first and second positions ( FIGS. 11 and 12 respectively) relative to the toothed portion. The coil-spring 88 biases the movable portion 82 toward the first position, and the fur ejector portion 80 otherwise operates similarly to the fur ejector portion 26 described in the preceding paragraphs. In view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained. While the present invention has been described in reference to a specific embodiment, in light of the foregoing, it should be understood that all matter contained in the above description or shown in the accompanying drawings is intended to be interpreted as illustrative and not in a limiting sense and that various modifications and variations of the invention may be constructed without departing from the scope of the invention defined by the following claims. Thus, other possible variations and modifications should be appreciated. Furthermore, it should be understood that when introducing elements of the present invention in the claims or in the above description of the preferred embodiment of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Additionally, the term “portion” should be construed as meaning some or all of the item or element that it qualifies. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations. Still further, the order in which the steps of any method claim that follows are presented should not be construed in a manner limiting the order in which such steps must be performed.	A pet grooming tool is provided with a fur ejector portion that is at least partially movable relative to the teeth of the pet grooming tool and can be manually moved into engagement with fur that is wedged or lodged between the teeth. The engagement of the fur ejector portion with the fur forces the fur from the gaps between the teeth. Preferably, the fur ejector portion can be manually moved by the same hand a person uses to support and hold the grooming tool.	0
The present invention concerns a process for the preparation of scalenohedral calcium carbonate suitable for use especially as a filler in papermaking or as a pigment in a paper coating composition. BACKGROUND OF INVENTION Since about 1920, chemically precipitated calcium carbonate has been used as a pigment or filler in the paper industry. Various chemical routes have been followed to precipitate the calcium carbonate, but the most frequently used methods are based on the double decomposition of sodium carbonate with either calcium hydroxide or calcium chloride, or on the carbonation with carbon dioxide gas of an aqueous suspension of calcium hydroxide ("milk of lime"). Double decomposition processes generally employ by-products of other chemical processes and therefore tend to yield calcium carbonate products which contain unwanted salts. The process based on the carbonation of milk of lime is performed in three stages; firstly, the calcination of raw limestone to produce calcium oxide or "quicklime"; secondly, the "slaking" of the quicklime with water to produce an aqueous suspension of calcium hydroxide; and finally, the carbonation of the calcium hydroxide with a gas comprising carbon dioxide. In order to prepare a precipitated calcium carbonate for the paper industry, a process based upon the carbonation of milk of lime is preferred because there is no serious problem of contamination of the product with unwanted salts, and each of the three stages in the production process can be controlled to adjust the properties of the final product. Calcium carbonate can be precipitated from aqueous solution in three different crystal forms: the vaterite form which is thermodynamically unstable, the calcite form which is the most stable and the most abundant in nature, and the aragonite form which is metastable under normal ambient conditions of temperature and pressure, but converts to calcite at elevated temperature. The aragonite form crystallises as long, thin needles having a length:diameter ratio of about 10:1, but the calcite form exists in several different shapes of which the most commonly found are the rhombohedral shape in which the length and the diameter of the crystals are approximately equal, and the crystals may be either aggregated or unaggregated; and the scalenohedral shape in which the crystals are like double, two-pointed pyramids having a length:width ratio of about 4:1, and which are generally unaggregated. All these forms of calcium carbonate can be prepared by carbonation of milk of lime by suitable variation of the process conditions. A particularly desirable type of pigment for the paper industry is known as a "bulking pigment". The opacity and brightness of a paper sheet filled or coated with a mineral material depend on the ability of the sheet to scatter light. If the pigment consists of fine particles which are separated by small spaces or voids, the scattering effect is generally enhanced, and is found to be at an optimum when the width of the spaces or voids is about half the wavelength of visible light, or about 0.25 microns. Bulking pigments, or pigments consisting of fine particles separated by spaces or voids of about the optimum size, are desirable in the paper industry on account of their ability to scatter visible light, but if the pigment consists of discrete fine particles, the retention of these particles in a matrix of cellulosic papermaking fibres is poor. To obtain good retention, the fine particles must be aggregated together to form clusters of larger size. High light scattering pigments currently available to the paper industry include titanium dioxide, which is very effective but also expensive, and fine kaolin particles which have been aggregated either thermally or chemically. Pigments derived from kaolin are also effective in scattering light, but are again expensive. Of the various forms of calcium carbonate, the aragonite form is effective as a high light scattering pigment but the process conditions necessary for its production are stringent and difficult to control. The rhombohedral form has crystals which are generally unaggregated and which pack together too closely and do not leave between them voids or spaces of the appropriate size. The scalenohedral form may be produced relatively inexpensively and the process conditions may be readily controlled to give aggregates of fine crystals separated by spaces of substantially the optimum size for light scattering, and is therefore the preferred form of calcium carbonate for use as a bulking pigment in the paper industry. U.S. Pat. No. 2,081,112 (N. Statham & T.G. Leek) describes a process for producing precipitated calcium carbonate by carbonating milk of lime. It is recognised that the more violent the agitation in the gas absorber, the finer will be the product, and the aim is to create a fine mist of calcium hydroxide slurry in the presence of the carbon dioxide-containing gas. The temperature in the gas absorber is maintained at 50°-60° C., preferably around 55° C. U.S. Pat. No. 2,964,382 (G.E. Hall, Jnr) concerns the production of precipitated calcium carbonate by various chemical routes in which calcium ions are contacted with carbonate ions in a precipitation zone, including the carbonation of milk of lime. High shear, intense turbulence is provided in the precipitation zone by means of an impeller rotating at a peripheral speed of at least 1160 feet per minute (589 cm. per second). U.S. Pat. No. 3,320,026 (W.F. Waldeck) describes the production of different forms of calcium carbonate including the scalenohedral form. The calcium hydroxide is relatively coarse and contains at least 50% by weight of particles larger than 10 microns. The temperature in the gas absorber is maintained at less than 20° C. U.S. Pat. No. 4,018,877 (R.D.A. Woods) describes a carbonation process in which there is added to the suspension in the gas absorber, after the calcium carbonate primary nucleation stage and before completion of the carbonation step, a complexing agent for calcium ions, such as ethylenediamine tetraacetic acid (EDTA), aminotriacetic acid, aminodiacetic acid or a hydroxy polycarboxylic acid. U.S. Pat. No. 4,157,379 (J. Arika et al) describes the production of a chain-structured precipitated calcium carbonate by the carbonation of calcium hydroxide suspended in water in the presence of a chelating agent and a water-soluble metal salt. U.S. Pat. No. 4,367,207 (D.B. Vanderheiden) describes a process in which carbon dioxide-containing gas is introduced into an aqueous calcium hydroxide slurry containing an anionic organpolyphosphonate electrolyte to give a finely divided precipitated calcium carbonate. OBJECT OF THE INVENTION It is an object of this invention to provide a method of producing a calcium carbonate bulking pigment for the paper industry which is at least as effective in light scattering as an aggregated kaolin pigment but less expensive. SUMMARY OF INVENTION A precipitated calcium carbonate having improved light scattering properties is prepared by a process comprising the following steps: (a) slaking quicklime in an aqueous medium; (b) carbonating the suspension of slaked lime formed in step (a) by passing therethrough sufficient of a gas comprising carbon dioxide to cause the pH of the suspension to fall to substantially neutral (about 7); and (c) separating the precipitated calcium carbonate formed in step (b) from the aqueous medium in which it is suspended. According to the present invention there is added to the aqueous medium in which the quicklime is slaked in step (a) a reagent having one or more active hydrogen atoms, or a salt thereof. The reagent is selected from the group consisting of triethanolamine, mannitol, diethanolamine, bicine, morpholine, tri-isopropanolamine, N-ethyl diethanolamine, N,N-diethylethanolamine and sodium boroheptonate. The reagent is added to the aqueous medium in which the quicklime is slaked, rather than at a later stage, as it is thought that the enhanced scattering coefficients obtained from precipitated calcium carbonate produced by the above method are achieved as a result of this earlier addition. The presence of the reagent during the slaking operation appears to inhibit the formation of aggregates or agglomerates of the fine particles of quicklime. The aqueous suspension of slaked lime which is formed comprises fine, discrete particles of slaked lime, and carbonation of a slaked lime suspension of this type yields a precipitated calcium carbonate having desirable light scattering properties. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Preferably the reagent is a polyhydric alcohol, a polyhydric phenol, a polybasic acid, a protein or a compound of the general formula: ##STR1## in which R1 and R2 (which may be the same or different) are each a hydrogen atom, a hydrocarbon radical having from 1 to 8 carbon atoms, a radical of the formula --(CH 2 ) p-COOM1, where p is 1-4, and M1 is hydrogen, an alkali metal or ammonium, or a radical of the formula --(CH 2 )q--OX where q is 2-5 and X is hydrogen or a hydrocarbon radical having from 1 to 8 carbon atoms; and R3 is a hydrocarbon radical having from 1 to 8 carbon atoms, a radical of the formula --(CH 2 )p-COOM1, where p is 1-4 and M1 is hydrogen, an alkali metal or ammonium, or a radical of the formula --(CH 2 )q--OX where q is 2-5 and X is hydrogen or a hydrocarbon radical having from 1 to 8 carbon atoms or a radical of the formula --(CH 2 )r--N[ CH 2 )s-COOM2] 2 , where r and s (which may be the same or different) are each 2-5 and M2 is hydrogen, an alkali metal or ammonium. Alternatively both R2 and R3 may be replaced by a radical of the formula: --(CH 2 )t --O-- (CH 2 )t, where t is 2-5. The amount of the reagent used is preferably in the range from 0.01 to 15%, preferably from 0.5 to 10% based on the weight of dry calcium oxide. In order to produce calcium carbonate in the scalenohedral form, the quicklime is preferably added to sufficient of the aqueous medium to give, on completion of step (a), a suspension having a calcium hydroxide concentration of from 0.7M to 4M (5-30% w/v). The temperature of the aqueous medium is preferably maintained in the range from 30° to 50° C. and the aqueous medium is preferably subjected to substantially continuous agitation during the slaking step. The duration of the slaking step is conveniently in the range from 15 to 30 minutes. On completion of the slaking step the suspension is preferably poured through a sieve of aperture size in the range from 40 to 70 microns in order to remove unslaked lime and other undesirable impurities. In step (b), in order to produce calcium carbonate in the scalenohedral form, the suspension of slaked lime is preferably diluted, if necessary, to a concentration of not more than 15% w/v and maintained at a temperature in the range from 40° to 65° C. The carbonating gas preferably contains from 5% to 50% by volume of carbon dioxide, the remainder being conveniently air or nitrogen. The carbon dioxide-containing gas is preferably admitted into the suspension of slaked lime in the form of fine bubbles. This may be achieved, for example, by admitting the gas under pressure through a perforated plate gas sparger. The rate of admission of the carbon dioxide-containing gas is preferably in the range from 0.02 to 0.10 moles of carbon dioxide per minute per mole of calcium hydroxide. The suspension is preferably agitated substantially continuously throughout the carbonation step, suitably by means of an impeller rotating at a peripheral speed of at least 200 cm.s -1 and preferably monitored throughout the carbonation step so that the admission of the carbon dioxide-containing gas may be stopped when the pH has fallen to about 7. In step (c) the precipitated calcium carbonate is preferably separated from the aqueous medium in which it is suspended by filtration. The filter cake may then be thermally dried and milled in order to provide a substantially dry, powdered product, or alternatively the filter cake may be redispersed by means of a dispersing agent for the calcium carbonate in order to provide a concentrated aqueous suspension suitable for use, for example, in a paper coating composition. The present invention will now be described in more detail, with reference to the following illustrative Examples. EXAMPLE 1 A sample of quicklime prepared by calcining French limestone was added to sufficient water at 40 degrees Celsius to give, on completion of slaking, a slurry with a calcium hydroxide concentration of 1M (7.4% w/v). The water also contained 1% by weight, based on the dry weight of calcium oxide, of triethanolamine. The mixture was stirred vigorously for 25 minutes and was then poured through a No. 300 mesh British Standard Sieve (nominal aperture 53 microns) to remove any undispersed residue. 150 ml of the resulting calcium hydroxide slurry was carbonated by passing therethrough a gas containing 25% by volume of carbon dioxide in compressed air at a rate of 0.04 moles of carbon dioxide per minute per mole of calcium hydroxide. The carbonation took place in a vessel having a water jacket through which water was circulated in order to maintain a substantially constant temperature of 45 degrees Celsius within the reaction vessel. The gas containing carbon dioxide was admitted at the bottom of the reaction vessel through a perforated plate gas sparger immediately above which was a turbine impeller rotating at 2000 rpm. (peripheral speed 314 cm.per sec). The temperature and pH of the suspension in the reaction vessel were monitored and the carbonation was considered to be complete when the pH dropped to 7.0. The suspension was then filtered and the cake of precipitated calcium carbonate was remixed with water to form a suspension containing 30% by weight of dry calcium carbonate, which suspension was used to measure the Kubelka-Munk scattering coefficient, S, of the calcium carbonate by the following method: A sheet of a synthetic plastics paper material, sold by Wiggins Teape Paper Limited under the registered trade mark "SYNTEAPE", was cut into a number of pieces each of size 10 cm×6 cm, and each piece was weighted and tested for percentage reflectance to light of 457 nm. wavelength when placed over a black background by means of an Elrepho spectrophotometer to give the background reflectance R b . The preweighed pieces of plastics paper were then coated with different amounts of the suspension of precipitated calcium carbonate to give coat weights in the range from 5 to 20 g.m -2 . Each coating was allowed to dry in the air and the area of dry coating on each piece of plastics paper was standardised by placing a circular template over the coating and carefully removing surplus coating which lay outside the periphery of the template. Each piece of plastics paper bearing a coated area was then reweighed, and, from the difference in weight and the dimensions of the coated area, the coat weight X in kg.m -2 was calculated. Each coated area was then tested for reflectance to light of 457 nm. wavelength when the piece of plastics paper was placed (a) on a black background (R o ): and (b) on a pile of uncoated pieces of the plastics paper (R l ). Finally the reflectance to light of 457 nm. wavelength was measured for the pile of uncoated pieces alone (r). From these measurements the reflectance Rc of the coating alone was calculated from the formula: ##EQU1## and the transmission T c of the coating from the formula: ##EQU2## From these two quantities it is possible to calculate a theoretical value for the reflectance, R oo , of a coating layer of infinite thickness of the same material from the formula: ##EQU3## The Kubelka-Munk scattering coefficient S in M 2 .kg -1 may now be calculated from the formula: ##EQU4## The scattering coefficient S was plotted against the coat weight X and the value of S for a coat weight of 8 g.m -2 was found by interpolation. The value of S was found to be 301 m 2 .kg -1 . The specific surface area of the calcium carbonate measured by the B.E.T nitrogen adsorption method was found to be 20.6 m 2 g -1 . As a comparison the experiment was repeated exactly as described above, except that no triethanolamine was added to the water in which the quicklime was slaked. In this case the value for S at a coat weight of 8 g m -2 was found to be 200 m 2 .kg -1 . The specific surface area of the calcium carbonate was found to be 9.8 m 2 g -1 . EXAMPLE 2 Example 1 was repeated except that, instead of triethanolamine, there were added to the water in which the quicklime was slaked 1%, based on the weight of dry calcium oxide, of each of the reagents listed in Table 1 (and in one case, as a control, with no reagent added). In each case a sample of precipitated calcium carbonate was prepared as described in Example 1 and the Kubelka-Munk scattering coefficient S at a coat weight of 8 g.m -2 was measured as described above. The results are given in Table 1: TABLE 1______________________________________ Scattering CoefficientReagent m.sup.2 kg.sup.-1______________________________________Mannitol CH.sub.2 OH (CHOH)4 CH.sub.2 OH 269Diethanolamine HN (CH.sub.2 CH.sub.2 OH).sub.2 274Triethylamine N(C.sub.2 H.sub.5).sub.3 240Diethylene glycol O(CH.sub.2 CH.sub.2 OH).sub.2 245Bicine (CH.sub.2 CH.sub.2 OH).sub.2.N.CH.sub.2 COOH 283 ##STR2## 273Tri-isopropanolamine N(CH.sub.2 CHOHCH.sub.3).sub.3 264N-ethyldiethanolamine C.sub.2 H.sub.5 N(CH.sub.2 CH.sub.2 OH).sub.2 261N,N-diethylethanolamine (C.sub.2 H.sub.5).sub.2 N CH.sub.2 CH.sub.2 261None 220______________________________________ EXAMPLE 3 Example 1 was repeated except that, instead of triethanolamine, there were added to the water in which the quicklime was slaked various percentages by weight, based on the weight of dry calcium oxide, of sodium boroheptonate. In one case, as a control, no reagent was added to the water. In each case a sample of precipitated calcium carbonate was prepared as described in Example 1 and the Kubelka-Munk scattering coefficient S at a coat weight of 8 g.m -2 was measured as described above. The results are given in Table 2: TABLE 2______________________________________% by wt. of sodium boroheptonate scatteringbased on wt. of dry calcium oxide coefficient (m.sup.2 kg.sup.-1)______________________________________0 2400.2 2620.5 2801.1 3011.6 2762.7 254______________________________________ These results show that the scattering coefficient S reaches a maximum when the dose of the sodium boroheptonate is about 1% by weight, based on the dry weight of calcium oxide. EXAMPLE 4 Example 3 was repeated except that quicklime prepared by calcining a Belgian limestone was used. The specific surface area of the slaked lime before carbonation was measured by the BET nitrogen adsorption method. A sample of precipitated calcium carbonate was prepared from each batch of the slaked lime as described in Example 1 and the Kubelka-Munk scattering coefficient S at a coat weight of 8 g.m -2 was measured as described above. The results are given in Table 3: TABLE 3______________________________________% by wt. of sodium Surface Scatteringboroheptonate based on area coefficientwt. of dry calcium oxide (m.sup.2.g.sup.-1) m.sup.2.Kg.sup.-1______________________________________0 15.0 2240.2 20.1 2330.5 28.0 2461.1 37.1 2691.6 44.1 2752.7 47.7 207______________________________________ These results show that although the specific surface area of the slaked lime continues to increase with increasing dose of the reagent, within the range of reagent doses which was investigated, the scattering coefficient S appears to reach a maximum at a reagent dose within the range from about 1% to about 2% by weight, based on the weight of dry calcium oxide. EXAMPLE 5 The following is for comparative purposes only. The experiment described in Example 1 was repeated except that no reagent was added to the water in which the quicklime was slaked. Instead there was added to the slurry of calcium hydroxide in the carbonation reaction vessel before carbonation with the carbon dioxide-containing gas was commenced, 1%, 10% and 40% by weight, respectively, based on the weight of dry calcium oxide, of triethanolamine. In each case a sample of precipitated calcium carbonate was prepared according to the method described in Example 1 and the Kubelka-Munk scattering coefficient S at a coat weight of 8 g.m -2 was measured and the results are set forth in Table 4: TABLE 4______________________________________% by weight of scattering coefficienttriethanolamine (m.sup.2.kg.sup.-1)______________________________________ 0 220 1 21710 25140 240______________________________________ Comparing these results with those obtained in Example 1, it can be seen that addition of triethanolamine at the carbonation stage, rather than the slaking stage, even at a dose of 40% by weight, based on the weight of dry calcium oxide, gave a very much smaller improvement in the scattering coefficient, compared with that which was obtained with addition of the reagent during the slaking step.	The calcium carbonate is prepared by: (a) slaking quicklime in an aqueous medium; (b) carbonating and neutralizing the suspension of slaked lime formed in step (a) using a gas comprising carbon dioxide; and (c) separating the precipitated calcium carbonate formed in step (b) from the aqueous medium in which it is suspended. There is added 0.01% to 15% by weight, based on the weight of dry calcium oxide, of a reagent having one or more active hydrogen atoms (or a salt thereof), to the aqueous medium in which the quicklime is slaked in step (a). The reagent is selected from the group consisting of triethanolamine, mannitol, diethanolamine, bicine, morpholine, tri-isopropanolamine, N-ethyl diethanolamine, N,N-diethylethanolamine and sodium boroheptonate.	2
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 USC 119 from Italian Patent Application No. N. MI2011A002046, filed on Nov. 11, 2011, incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to a yarn storage feed device in accordance with the introduction to the main claim. In particular, the invention relates to a yarn storage feed device able to measure with absolute precision the fed yarn quantity and the yarn quantity present on the drum. BACKGROUND OF THE INVENTION Various types of yarn feed devices or feeders are known in which the yarn originating from a spool or bobbin is deposited onto a fixed drum loaded by an external member driven by its own motor, or onto a rotating drum from which it is withdrawn by the textile machine. In these feeders a system has necessarily to be provided for measuring or counting the number of turns present on the drum such that the yarn stock present on this latter remains virtually constant, and to prevent it from being totally consumed by the machine, with obvious problems for the operation thereof. Various methods for measuring the yarn quantity (or number of turns) present on the drum are known. A first of these utilizes the reflection of light generated by an emitter and received by a corresponding receiver which are associated with the feeder. One or two reading zones (comprising emitters and receivers) are used to verify that at least one turn is present within them. Usually, one is positioned at the drum entry (yarn inlet zone) and one at the drum exit (yarn outlet zone) to control the so-called minimum stock and maximum stock respectively. Feeders provided with this type of control are however able to ensure only that the number of turns is within a given range, but are not able to know their exact number (with the consequent impossibility of knowing how much yarn is stored on the drum, of which the lateral surface area is known). The aforedescribed reflection method also has the limit of its well known dependence on the colour of the yarn to be monitored, and which can negatively affect the effectiveness of sensing the yarn by the optical elements utilized by the method under examination. Feeders are also present in which the turns unloaded from the drum (and hence the fed yarn quantity) can be counted, again by reflection, however these known devices also present the limit that the reading resolution is strongly influenced by the yarn colour and by any dirt and dust deposits on the optical elements by which the number of turns is measured. Other feed devices comprise optical elements inserted into a single emitter/receiver member and hence do not comprise separated emitter and receiver portions. This emitter/receiver member is of barrier operation and is able to measure the yarn quantity which has moved in front of it (i.e. the yarn quantity fed and hence the yarn quantity remaining on the drum), however as it does not know the exact position of the yarn within the sensor it is unable to know the yarn position at the feeder outlet, consequently it is unable to offer optimal resolution and precision. Other feeders comprise mechanical solutions using mechanical lever detectors to which sensors (proximity sensors, Hall sensors) are connected to determine a minimum and a maximum yarn stock on the drum. Such solutions again do not enable the number of turns present on the drum to be known exactly; moreover, the mechanical action of the levers modifies the yarn tension, with obvious repercussions on the yarn fed to the textile machine. SUMMARY OF THE INVENTION An object of the invention is to provide a feed device able to measure with absolute precision the yarn stored on the drum and simultaneously the yarn quantity withdrawn by the textile machine. Another object of the present invention is to provide a device able to monitor a yarn feed which does not suffer from those limits of reflection-operated optical solutions related for example to the yarn colour and to dirt accumulation. A further object of the present invention is to provide a device which is not influenced by the presence of dust or the like, by being subjected to cleaning by yarn passage along the device. Another object of the present invention is to provide a device able to measure with high resolution the yarn quantity absorbed (AYL) by the textile machine. A further object of the present invention is to provide a device which does not influence the yarn during its passage from the feeder to the textile machine. Another object of the present invention is to provide a device able to sense the lack of yarn or its breakage and possibly to indicate this to the textile machine. A further object of the present invention is to provide a device able to count with absolute precision the number of turns deposited on the drum during its loading, starting from the unloaded drum and during all the subsequent operative stages of withdrawal by the textile machine. These and other objects which will be apparent to the expert of the art are attained by a feed device in accordance with the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more apparent from the accompanying drawings, which are provided by way of non-limiting example and in which: FIG. 1 is a perspective view of a device formed in accordance with the invention; FIG. 2 is a section therethrough on the line 2 - 2 of FIG. 1 ; FIG. 3 is a front view of the section of FIG. 2 ; FIG. 4 is a section on the line 4 - 4 of FIG. 1 ; FIG. 5 is a section on the line 5 - 5 of FIG. 4 ; FIG. 6 is a view similar to that of FIG. 4 , but of a variant of the invention; and FIG. 7 is a section on the line 7 - 7 of FIG. 6 . DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to said figures, a feed device according to the invention is indicated overall by 1 and comprises a casing 2 provided with a fixing bracket 3 to enable the device to be fixed to a support (not shown) associated with, or close to, a textile machine (not shown). The casing 2 carries a rotary member or drum 5 driven (in any known manner) by its own electric motor or actuator 6 (with hollow shaft 6 A) contained within the casing 2 . A yarn F is wound about this drum before leaving the feed device and reaching the textile machine; the yarn F forms a plurality of turns 7 on the drum 5 to hence define a yarn stock for the machine such as to always enable its optimal operation even in the presence of discontinuous yarn withdrawals by said machine, for producing a particular article (for example a mesh). The yarn F entering the device 1 cooperates with one or more thread guides 10 (only one being shown in the figures), for example of ceramic, which define its trajectory in entering said device such as to prevent the yarn F from coming into contact with the casing 2 (hence undergoing damage or creating overtensions deleterious for the proper operation of the device 1 and for correct yarn feed to the textile machine). The feed device 1 preferably presents an entry yarn brake 11 and a tension sensor 12 , of known type and therefore not described. The thread guide 10 and the yarn brake 11 project from the casing 2 . The feeder 1 presents an optical sensor 13 to measure the quantity of yarn F on which the feeder operates. The sensor 13 comprises a first part 15 and a second part 16 surrounding the first; the first part is defined by a part 17 (totally or partly, for example in a lateral surface 22 thereof, of any known light transparent material), disposed coaxially to the rotary drum 5 and containing a plurality of light emitting members or transmitting photodiodes 18 . The part 17 is supported by the casing 2 via a tube 19 positioned within the hollow shaft 6 A and fixed at one end 18 A to this casing. The cable for handling the necessary signals sent and received by the sensor 13 passes within the tube. The photodiodes 18 are associated with an electronic circuit or electronic card 21 contained in the part 17 which is present in a stationary position at one end of the drum 5 from which the yarn F leaves to reach the textile machine. The second part 16 of the sensor 13 , also stationary, is defined by a hollow annular part 23 present at the casing 2 . The part 23 comprises at least one transparent portion 26 facing the first part 15 and containing a plurality of receiver photodiodes 30 , of a number equal to the number of transmitter photodiodes 18 and disposed within the part 16 such as to receive the light signals emitted by the corresponding transmitter 18 (for example such as to face these emitters). The receivers 30 are also associated with an electronic circuit or card 33 inserted into the part 16 and connected electrically to a control unit 35 of the device 1 to control the feeder operation. The unit 35 , in particular, cooperates with a memory unit (not shown) in which the “physical” data of the rotary drum 5 , i.e. its diameter, are contained; the unit 35 also commands and controls the operation of the motor 6 , of which the rotational velocity is hence always known by known control elements (for example Hall sensors). During use of the device 1 , the yarn F unwinds from a corresponding bobbin or spool (not shown), and passes through the thread guide 10 and the yarn brake 11 . At this point the yarn F is wound onto the drum for a predetermined number of turns 7 (possibly programmable); the purpose of this drum is to feed the yarn F by withdrawing it from the spool in order to feed it to the textile machine, while at the same time separating said yarn present on the drum such that the individual turns 7 are unable to superimpose on and/or touch each other. Before abandoning the device, the yarn F passes through the sensor 12 which, by known methods, measures its tension, then it possibly passes through a further braking member (not shown) which further determines and controls its braking. In proximity to its point of exit from the drum 5 , the yarn F passes through the optical sensor 13 shown in greater detail in FIG. 5 . By way of example, this shows four transmitters (indicated by 18 A, B, C, D) and four receiver photodiodes ( 30 A, B, C, D), the yarn F withdrawn by the textile machine (and shown as a circumference as it detaches from the drum 5 ), and the parts of the sensor 13 . The photodiodes 18 and 30 determine four light rays or beams which the yarn F interrupts by passing in front of them, i.e. “light barriers” which are indicated in FIG. 5 by A, B, C, D. The suitably conditioned signal (i.e. amplified and filtered by known electrical/electronic members, not shown, associated with the card 33 ) of each receiver element 30 A, B, C, D is fed to the control unit 35 of the entire device. This control unit, by analyzing the state of each barrier and knowing the drum rotation direction, is able to verify the yarn position and to know if the yarn has been loaded onto or unloaded from the drum, during the operating stages of the textile machine. In this respect, it will be assumed that the drum 5 on which the yarn F is deposited rotates clockwise; when the control unit 35 senses a barrier activation sequence (i.e. the sequence of interruption of light beams between the pairs of transmitter photodiodes and receivers 18 A, B, C, D and 30 A, B, C, D) of the type A→B→C→D→A→B→C . . . , it determines that this yarn has been loaded on the drum and defines this sequence as a LOAD sequence. When the electronic control unit 35 senses a barrier activation sequence of the type D→C→B→A→D→C . . . , it determines that this yarn F has been unloaded from the drum 5 and defines this sequence as an UNLOAD sequence. It is therefore evident that by utilizing the data originating from the optical sensor 13 and by knowing and regulating the velocity and position of the feed drum, the control unit 35 is able to perform the following operations: 1) during the loading of the device 1 (sequence in which the yarn is wound onto the drum starting from a drum 5 unloaded condition), the unit 35 counts with absolute precision the number of turns 7 loaded, from which the yarn quantity in mm available as stock can be obtained with precision. In this respect, the control unit 35 causes the drum 5 to rotate at a fixed or variable velocity (by commanding and controlling the motor 6 in any known manner) and monitors the optical sensor 13 , to halt the movement of the drum 5 as soon as it has counted a number of change-overs (A→B, B→C, . . . ) equal to four times the number of revolutions to be carried out. 2) The unit 35 senses that the textile machine has begun to withdraw yarn from the feeder when, by analyzing the barrier activation sequence, it determines that an UNLOAD sequence is underway. In response to an UNLOAD sequence, this unit begins to rotate the drum 5 such that the number of turns 7 present as stock remains constant and equal for example to a possibly programmable predetermined value. In particular, the control unit 35 increases o decreases the velocity of the motor 6 which controls the drum in response to an UNLOAD sequence or LOAD sequence respectively, in accordance with known control algorithms (for example P, PI, PD, PID), by closing a control loop for the yarn quantity present on the drum. Then by processing the data relative to drum velocity and position and the state of the optical sensor 13 , the control unit always known with absolute precision the yarn quantity present on the drum (stock) and the yarn quantity withdrawn by the machine in real time. The yarn quantity present on the drum (known hereafter as REAL TIME YARN STOCK) is in fact the algebraic sum of the UNLOAD and LOAD sequence with respect to the initial yarn quantity known as the YARN STOCK. For example, assuming that the drum 5 has a linear development equal to 200 mm and assuming that during the loading stage the device has loaded ten turns and hence 2000 mm of yarn (turn number×development→10×200=2000), then at each UNLOAD sequence a value of 50 mm (development/number of sensors→200/4=50) is subtracted from the yarn quantity present on the REAL TIME YARN STOCK, whereas at each LOAD sequence a value of 50 mm is added. A brief numerical example follows: SENSOR YARN REAL TIME SEQUENCE CODE STOCK STOCK 2000 2000 A→B LOAD 2000 2050 B→C LOAD 2000 2100 C→B UNLOAD 2000 2050 The yarn quantity withdrawn by the textile machine is given by the difference between the initial yarn quantity YARN STOCK and the actual yarn quantity REAL TIME YARN STOCK added to the number of drum revolutions. Let us imagine that the control unit 35 does not cause the drum 5 to rotate in order to reload the yarn withdrawn by the machine; in this case the withdrawn yarn quantity (ABSORBED YARN QUANTITY AYL) must be incremented by 50 mm for each UNLOAD pulse. A numerical example follows: SENSOR REAL TIME FED YARN SEQUENCE CODE YARN STOCK QUANTITY 2000 0 B→A UNLOAD 1950 50 A→D UNLOAD 1900 100 D→B UNLOAD 1850 150 At the moment in which the control unit 35 begins to cause the drum 5 to reload from the bobbin or spool those turns withdrawn by the machine, the yarn quantity (AYL) is given by the algebraic sum of the YARN STOCK and the REAL TIME YARN STOCK to which a quantity of 200 mm (drum development) must be added for each motor revolution. This is shown in the following table. REAL TIME SENSOR YARN MOTOR FED YARN SEQUENCE CODE STOCK R.P.M. QUANTITY 2000 0 0 B→A UNLOAD 1950 0 50 A→D UNLOAD 1900 0 100 D→A LOAD 1950 1 250 From the previously given examples it is apparent that the unit 35 is able to measure with absolute precision the value of the stock of yarn F and the yarn quantity absorbed (AYL) by the textile machine. It should be noted that the resolution of the two measurements can be improved; for example, the number of optical barriers can be incremented, such as to reduce the minimum increment and decrement step calculated as the drum development divided by the number of barriers. An encoder can be used to know the exact position of the motor 6 and hence of the drum 5 such that the contribution given by the rotation of the motor 6 in the calculation of the fed yarn quantity is not an exact multiple of the drum development, but a function of its position (hence also taking account of the fractions of a revolution, with greater encoder resolution and greater measurement resolution). For example by using a 4096 position encoder, precisions can be achieved which are less than one tenth of a millimeter. One of the possible embodiments of the invention has been described; others are however possible in the light of the preceding description. For example, the number of barriers could be greater or less than four, odd or even, and comprise at least one pair of emitters and at least one pair of receivers; obviously, as the number of barriers increases, the counting precision varies, as already indicated. Moreover, the barriers could operate not “by interruption” but “by reflection”; hence in this latter case, each transmitter and the corresponding receiver lie on the same part 15 or 16 of the sensor 13 , with a mirror being mounted on the opposite part ( 16 or 15 ), such that the system again operates as a barrier. According to another variant, the passage of the yarn F is intercepted not as the interruption of a light beam but as the sliding of the yarn. This solution has the great advantage of verifying yarn passage not within a single point (crossing of the barrier light beam), but within an angular sector centred on the receiver element. This enables the passage condition to be intercepted with greater safety as it derives not from an instantaneous condition but from a condition of greater duration in terms of time. This makes the sensor much more robust and able to read any type of yarn with precision, in particular even very thin yarns. As an alternative to that described, the barriers or the generated light beams could be partially superimposed in pairs, such as to have for each sensitive element two signals CHA and CHB and hence obtain the passage and direction data from the state of the transition CHA→CHB or vice versa (unwind, wind→LOAD, UNLOAD). In this manner the sensor 13 operates as an optical encoder. FIGS. 6 and 7 , in which parts corresponding to those of the already described figures are indicated by the same reference numerals, show a further variant of the invention. According to this latter, the transmitters and the corresponding receivers are located on the second part 16 of the sensor 13 , the first part 15 now having been eliminated. The second part 16 surrounds the member 5 even though distant therefrom (lower, in FIG. 6 ). This second part contains the emitters 18 and receivers 30 . The operation of the device shown in FIGS. 6 and 7 is evidently the same as that shown in the already described figures. Finally, if the feed device is formed as a fixed drum solution and hence the hollow shaft (which passes through it) is used for yarn passage, the hollow shaft transports the electrical signals for controlling the optical sensor. These embodiments are also to be considered as falling within the scope of the invention as defined by the following claims.	A storage feed device for a yarn which unwinds from a corresponding bobbin and is fed to a textile machine. The device includes a rotary or fixed drum and an optical sensor member arranged to sense the movement of the yarn towards the textile machine. The optical sensor includes a plurality of emitters and receivers between which a light beam is generated and is interrupted by the yarn during its movement. The optical sensor includes a first fixed part and a second fixed part which includes the emitter and receiver elements, the first part being coaxial with the rotary member, the second being annular and surrounding the first part, the yarn moving between the parts.	3
FIELD OF THE INVENTION [0001] The present invention relates to storing data on a tape in accordance with a format in which tape usage information is logged on the tape. BACKGROUND OF THE INVENTION [0002] It is known to provide the storage and retrieval of digital information on magnetic tape in a format that is referred to as the DDS format which has developed through a number of versions. In a DDS tape drive, a magnetic tape cassette is loaded into the tape drive and the tape in the cassette is transported past a rotary head drum to record overlapping oblique tracks across the tape. The DDS format provides for a number of specific areas on the tape including a device area for loading and testing the tape, a system area that includes a tape log and a data area for recording user data. The tape log is provided to record tape usage information. The tape log is read when a tape cassette is loaded into the tape drive and the tape log is updated by being overwritten when the tape cassette is unloaded. [0003] If problems occur during an update of the tape log, due to a head clog or a power cycle failure, then the log can be corrupted rendering it useless on subsequent tape loading operations. In addition, if the tape drive has had problems in writing data to the tape, it may be considered too risky to attempt an update of the tape log for fear of corrupting the log. In this case the cassette may be ejected without the current tape usage information being added to the log. SUMMARY OF THE INVENTION [0004] According to the present invention, there is now provided data storage apparatus for storing data on a tape, the apparatus comprising; [0005] recording means to load the tape for a data recording session and to unload the tape following the data recording session, the recording means being operable to record the data in accordance with a format specifying a system area of the tape for storing a plurality of logs of tape-usage information, and a data area of the tape for storing the said data, and [0006] control means programmed to access the data in one of the said logs for use at each loading of the tape and to update one of the said logs at each unloading of the tape, the control means being programmed to select the most recently updated log to be accessed at each loading of the tape and to update the least recently updated log at each unloading. [0007] Further according to the present invention, there is provided a method of storing data on a tape by means of data storage apparatus operable to load the tape for a data recording session and to unload the tape following the data recording session, the method comprising the steps of; [0008] recording the data in accordance with a format specifying a system area of the tape for storing a plurality of logs of tape-usage information, and a data area of the tape for storing the said data, and [0009] accessing the data in one of the said logs for use at each loading of the tape and updating one of the said logs at each unloading of the tape, the most recently updated log being accessed for use at each loading of the tape and the least recently updated log being updated at each unloading of the tape. DESCRIPTION OF THE DRAWINGS [0010] The invention will now be described, by way of example only, by reference to the accompanying drawings in which; [0011] FIG. 1 shows a block diagram of the components of a magnetic tape recording system embodying the present invention; [0012] FIG. 2 shows the main physical components of a tape deck included in the system of FIG. 1 , [0013] FIG. 3 is a diagrammatic representation of two data tracks recorded on a tape by means of the tape deck of FIG. 2 , [0014] FIGS. 4 and 5 are diagrams showing the overall layout of a tape recorded in accordance with the present invention, and [0015] FIG. 6 is a flow diagram of steps to select between system logs recorded on the tape of FIGS. 4 and 5 . DETAILED DESCRIPTION OF THE INVENTION [0016] Referring to FIG. 1 , there is shown a data storage system 10 embodying the present invention. The system includes a host 11 coupled to a controller 12 via an interface 13 . The controller 12 is programmed to control a tape drive 14 that includes a drive engine 15 and a drive mechanism 16 . The drive mechanism is adapted to receive a tape cartridge 17 . A controlling software application on the host 11 controls the reading and writing of data on a magnetic data tape in the tape cartridge 17 . [0017] The host system 11 has at least one central processing unit (CPU) and a memory to store the controlling software application. The interface 13 connecting the host system 11 to the controller 12 may be any suitable proprietary standard bus known to those skilled in the art. [0018] The drive mechanism 16 includes electrical and mechanical components that receive, position and access tape cartridges. The drive mechanism has components to lock a tape cartridge in place, an ejection motor and read/write heads. The drive engine 15 is a data processor that is programmed to supervise the operations of the drive mechanism 16 and to manage the flow of data to be recorded in or read from a tape cartridge 17 received in the drive 14 . [0019] Referring to FIG. 2 , there is shown the basic layout of the tape drive 14 which is in the form of a helical scan tape deck 20 in which tape 21 from a tape cartridge 22 passes at an angle across a rotary head drum 23 . The tape is driven in the direction indicated by the arrows from a motor driven supply reel 24 to a motor driven take up reel 25 . A capstan 26 and pinch roller 27 control the passage of the tape past the head drum 23 . The rotary head drum 23 carries two magnetic write heads 28 A and 28 B spaced apart by 1800 and two read heads 28 C and 28 D also spaced apart by 1800 . The heads 28 A and 28 B are arranged to write a succession of overlapping oblique data tracks 30 , 31 on the tape as shown in FIG. 3 . The two tracks 30 , 31 are representative of a succession of tracks along the tape that are recorded according to a DDS format. The track written by the head 28 A has a positive azimuth while the track written by the head 28 B has a negative azimuth. Each pair of positive and negative azimuth tracks 30 , 31 constitutes a frame. [0020] The tape 21 may formatted so as to have a single space for data or may be formatted as a partitioned tape in which data may be recorded in one partition independently of data recorded in another partition on the tape. The present invention may be applied to either a single data space tape or a partitioned tape but for convenience will be described in relation to a partitioned tape. FIG. 4 shows the overall layout of the tape 21 when it is formatted as a two-partition tape. The two partitions are referred to as partition 1 and partition 0 , the partition 0 being, by convention, the furthest from the start of the tape 21 . In addition to the partitions themselves, there is an initial area 41 of the tape that is referred to as a device area that is used in the initial setting up of the tape 21 . [0021] The layout of partition 1 of the tape 21 consists of 5 areas that comprise a reference area 42 a , a system area 43 a , a data area 44 a , an end of data area 45 a and a post end of data area 46 a . The partition 0 also has a reference area 42 b , a system area 43 b , a data area 44 b , an end of data area 45 b and a post end of data area 46 b. [0022] The reference areas 42 a and 42 b are each used as a physical reference. The system area 43 a of partition 1 includes two system logs that are updated by being overwritten as will be described more fully below. The system area 43 b of partition 0 does not include system logs but has system frames that are written as a continuum upon tape format and are not overwritten until the next tape format. The data areas 44 a and 44 b are used for recording user data and are followed by the end of data areas 45 a and 45 b and the post end of data areas 46 a and 46 b. [0023] FIG. 5 shows the layout of the two system logs 51 a and 51 b in the system area 43 a of the tape 21 . The two logs 51 a and 51 b are referred to as system log 1 and system log 2 respectively. The system logs 1 and 2 are preceded by respective preambles 52 a and 52 b and followed by respective postambles 53 a and 53 b . Position tolerance bands 55 are provided to accommodate positioning tolerances when updating the system logs. A system area delimiter 56 is used as the physical reference when updating the system log 2 . [0024] Each of the system logs includes cyclic redundancy check (CRC) characters to enable the contents of the log to be validated. The system logs also each include a tape load count. The load count of the log in current use is updated upon each load of the tape so that the load counts can be compared so as to determine which of the logs is the most recent. [0025] Referring now to FIG. 6 , upon a tape load, the system log 1 is read in step 70 . The process continues to step 71 where the system log 1 is validated and in step 72 the system log 2 is read. The process continues on to step 73 where the system log 2 is validated. The process of validating the system logs is effected by reference to the CRC characters stored in the logs. In step 74 , a check is made on the validity of the system logs and, if both logs are found to be valid, the process continues to step 75 where the load counts of the two system logs are compared. If the load count of the system log 1 is greater than that of the system log 2 , then system log 1 is selected during a session of tape use in step 76 . Conversely, if the load count of the system log 1 is less than that of the system log 2 , then system log 2 is selected during a session of tape use in step 77 . [0026] If in the step 74 , it is determined that the system logs 1 and 2 are not both valid, a check is conducted in step 78 to determine if the system log 1 is valid. If so, the system log 1 is used in step 79 . If not, a check is made in step 80 whether the system log 2 is valid. If so, the system log 2 is used in step 81 . Finally, if neither of the system logs 1 and 2 is valid, the process moves to step 82 where recovery strategies are attempted to read both the system logs 1 and 2 . [0027] The drive controller 12 is programmed to control the drive 20 so that the system log that does not have its information used in a tape session is the log that is updated by being overwritten when the tape is unloaded. In other words, the controller 12 is programmed to update one of the system logs for each usage of the tape, the logs being selected in turn for updating according to which has been used in the tape session. The invention thereby provides the tape with at least one current log of tape usage and at least one log of earlier tape usage. The current log of tape usage is identified by the load count information contained in the log. [0028] When the tape is due to be unloaded, the drive controller 12 calculates the log values and the CRC to write to the log to be updated. If an attempt to update a system log fails, recovery actions are undertaken and a retry is made to update the same system log. No attempt is made to overwrite the other system log. If all recovery actions are exhausted and the system log has still not been successfully updated, the tape is ejected. [0029] Upon a subsequent load of this tape, the tape drive will read both the system logs and will use the latest complete log. If the prior update attempt has corrupted the system log, then the same log information will be used that was used during the previous load as already described and illustrated in FIG. 6 . [0030] What has been described is a tape drive that is programmed so that only the oldest or a previously corrupted log is overwritten during a tape unload. This provides more complete assurance that there is always a complete log that can be read on a subsequent load. It will be apparent that although the invention has been described in relation to a format providing two system logs, the system logs may number more than two.	Data storage apparatus is provided for storing data on a tape in accordance with a format specifying a plurality of logs of tape-usage information and a data area for storing the said data. Control means are programmed to update one of the said logs for each usage of the tape, the logs being selected in turn for updating.	6
FIELD OF THE INVENTION [0001] The present invention relates generally to a manufacturing process for semiconductors and more particularly to a system and method for efficiently manufacturing such devices. BACKGROUND OF THE INVENTION [0002] In the past few years, with the advent of Internet technology, serious software applications have emerged which intend to harness the power of a “connected” society to improve productivity. Most companies today advertise their services via the web and the more advanced companies provide useful operational data on their websites. This has at a minimum improved the customer service aspects of the business by providing information needed by the customers to make better decisions, faster. [0003] The goal is to enable companies who typically operate as semiconductor subcontractors during the manufacturing lifecycle to operate as a “virtual company”. There is important information that can be shared between these companies to optimize the supply chain and increase the efficiency of the production cycle. Because each company operates independently and has its own information systems, valuable data typically does not flow efficiently to the customers. This increases latency and delays response from the customer, causing potential delays in time to market. [0004] There are several layers of technology when it comes to exchanging information. Technologies are available at the network level, infrastructure level and application level. It is desired to be able to efficiently tie these technologies together to optimize the time to market for a particular product. [0005] Accordingly, what is needed is a system and method, which overcomes the above-identified problem. The present invention addresses such a need. SUMMARY OF THE INVENTION [0006] A method and system for manufacturing a supply chain collaboration is disclosed, the method and system comprising at least one customer including a first collaboration application and at least one collaboration partner including a second collaboration application. The system can also include more collaboration partners which can include a third or more collaboration applications. Each connected application allows for peer-peer collaboration therebetween. A system and method in accordance with the present invention utilizes peer-to-peer technology to securely and reliably transfer the data between the companies and promotes a “push” mechanism where information is shared as soon as it becomes available. BRIEF DESCRIPTION OF THE DRAWINGS [0007] [0007]FIG. 1 illustrates a collaborative menu server (CMS) system in accordance with the present invention. [0008] [0008]FIG. 2 illustrates managing a project. [0009] [0009]FIG. 3 describes the access request approval process. [0010] [0010]FIG. 4 illustrates maintaining purchase orders. [0011] [0011]FIG. 5 illustrates technical document sharing in accordance with the present invention. [0012] [0012]FIG. 6 illustrates the process for viewing work in progress (WIP) data. [0013] [0013]FIG. 7 illustrates providing reports using the CMS system. [0014] [0014]FIG. 8 illustrates issue tracking in accordance with the present invention. DETAILED DESCRIPTION [0015] The present invention relates generally to a manufacturing process for semiconductors and more particularly to a system and method for efficiently manufacturing such devices. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. [0016] Collaborative Manufacturing Server (CMS) system is a web based collaborative commerce suite, which allows different technologies to exchange information in an efficient manner. A centralized and web-based project server engine allows customers to manage projects on-line under a multi-user and personalized environment. The process of locating and acquiring required services is seamlessly streamlined through the use of an integrated CMS system. Customers can use a single browser window to locate service vendors, design document sets, and other information, including standard service cycle times. During the execution of the project, status updates are automatically sent to the customers. Other important documents related to the quality of the production are also automatically sent. Upon the completion of a project design cycle, the CMS system automatically delivers the manufacturing orders through a CMS system, which automates the customers' procurement tasks. A peer-to-peer technology is utilized to ensure that the sensitive data remains with concerned parties and not sent through a centralized hub mechanism. [0017] The CMS system is a distributed application unlike other collaboration tools. A server resides inside the firewall of each collaboration participant and communication occurs directly between the participants. [0018] [0018]FIG. 1 illustrates a collaborative manufacturing server (CMS) system 100 in accordance with the present invention. In such a system, a customer provides information to and receives information from a plurality of partners. The customers and manufacturing partners each have their own CMS application 102 , 104 and 106 respectively which allows for peer to peer collaboration therebetween. [0019] The supplier and customer platforms 102 and 104 provide information to and receive information from their respective back office applications 103 and 105 using, for example, a Semicon Collaboration Platform which is provided with CMS. The CMS system provides the following features: [0020] 1. Project Management [0021] Customers create a project for every integrated circuit that needs to be manufactured. Each project is a schedule of manufacturing tasks that need to be completed for the entire production cycle. Different partners perform these tasks. All the tasks are part of a single project regardless of which partner completes the tasks. When tasks are in progress, a status update is automatically shown to the customer via the peer to peer technology. Users can share the project information by adding other users to the project. To describe this feature refer now to the following description in conjunction with the accompanying figures. [0022] [0022]FIG. 2 illustrates managing a project. The other systems have their own manufacturing plan, demand forecasts and prototype development. These are inputs to a purchase requisition, via steps 202 , 204 and 206 . Purchase orders are then provided based on the purchase requisition, via step 208 and 210 Thereafter the purchase order is approved in the financial system. The approved purchase order number and other summary information is imported into CMS. Thereafter, a vendor access is requested within the CMS system, via step 214 . Then the access request is approved, via step 214 . After the access request is approved, then vendor services are selected, via step 216 . Finally, from that selection of vendor services a schedule is created via document sharing, via steps 220 and 222 . Thereafter, it is determined if there is scheduled confirmation, 224 . If it is a frozen project or the project, via step 22 , is completed, then the process is ended. However, if it is not frozen then the schedule creation step 220 is revisited. [0023] [0023]FIG. 3 describes the access request approval process. First, the access request is provided, via step 302 . First, it is determined if the permission is granted for the request for the person, via step 304 . If it is granted, then the permission for the person is changed, via step 308 If it is not granted, it is determined if there is a permission to schedule via step 306 . If there is no permission to schedule after step 308 , then end. If, on the other hand, there is a permission for schedule, change the permission for the vendor schedule, via step 310 . [0024] 2. Purchase Order Maintenance [0025] CMS imports the P.O data from the customer's financial system. There are two ways it can import the data. PO can be imported via a text file. Or it can be imported via an automated connection to the financial system. Summary purchase order information is captured and maintained in CMS. This purchase order information is automatically transferred to the service providers where it can import into the service provider's financial systems. All project data will be associated with the PO number for tracking purposes. To describe this feature refer now to the following description in conjunction with the accompanying figures. [0026] [0026]FIG. 4 illustrates maintaining purchase orders. The other systems have their own manufacturing plan 401 , demand forecasts 403 and prototype development 404 . These are inputs to a purchase requisition via step 402 . Purchase orders are then provided based on the purchase requisition via step 404 . Thereafter, the approved purchase order is imported into the CMS application via step 406 . [0027] 3. Document Sharing [0028] Customers and service providers share a number of technical documents. CMS allows the documents to be easily sent from the service providers to the customers. Revisions of the documents are automatically saved and updated on the customer's site. To describe this feature refer now to the following description in conjunction with the accompanying figures. [0029] [0029]FIG. 5 illustrates document sharing in accordance with the present invention. First, the service document change request is provided, via step 502 . It is first determined if a new directory is required, via step 504 . If a new directory is required, then a new directory is created, via step 506 . If none is required, or after step 506 , then it is determined if a new file needs to be created, via step 508 . If the answer is yes, then the new file is created, via step 510 . If the answer is no, or after step 510 , it is determined if a document must be imported, via step 512 . If the answer is yes, then a file is imported, via step 514 . If the answer is no, or after step 514 , then it is determined if a document needs to be exported, via step 516 . If the answer is yes, the file is exported, via step 518 . If the answer is no, or after step 518 then it is determined if the link document is required, via step 520 . If the answer to that is no, then end. If the answer is yes, then the document is linked to the service, via step 522 . [0030] 4. WIP Data [0031] One of the most important requirements from customers is the ability to view Work-In-Progress (WIP) data from the service provider's systems. Each service provider maintains the WIP data in their own formats. CMS allows easy connectivity to the service providers' WIP information system and the ability to transport the data to the customer's CMS application. Customers can view the WIP data in near real time (as soon as it becomes available) and in their own environment—they don't need to go to another website to view the information. This also gives them the ability to track planned vs. actual WIP information. To describe this feature refer now to the following description in conjunction with the accompanying figures. [0032] [0032]FIG. 6 illustrates the process for viewing work in progress (WIP) data. First, the WIP result is provided via step 602 . Then the WIP file is imported, via step 604 . Then there is an inquiry into the WIP result, via step 606 . It is then determined if there are more files via step 608 . If there are more files, then the above-identified steps 604 - 608 are repeated. If there are no more files, then the process is ended. [0033] 5. Generating Reports [0034] CMS provides a customizable report generation tool. Customers and other partners in the “supply chain” want to view reporting information as soon as it becomes available. CMS provides the ability for the reports to be generated automatically from the data sent by the service providers to the customers. Customers can decide which other service providers to share this information. Improved availability of information increases the response time to solve potential problems, thereby increasing the time to market. To describe this feature refer now to the following description in conjunction with the accompanying figures. [0035] [0035]FIG. 7 illustrates providing reports using the CMS system. First, a new report request is provided, via step 702 . Next, it is determined if a template exists, via step 704 . If a template does not exist, then a new template is created, via step 706 . If, on the other hand, a template does exist, or after the creation of the new template, inquiry is made about the template, via step 708 . After the template is provided, then a report is generated via step 710 and then it is determined if another report needs to be generated, via step 712 . If the answer is yes, then repeat the above-identified steps 704 - 712 . If the answer is no, then the process is ended. [0036] 6. Issue Tracking [0037] Very often issues arise during the production cycle and resolving the issue is not just the responsibility of one partner. It is a collaborative effort. Today, this is done using phone and fax. Using the on-line, near real-time Issue Tracking System in CMS, all partners can work to resolve the issues. Responses, including file attachments are automatically sent to all partners involved such that all partners can view the latest information available to help resolve the problems. This significantly reduces the time it takes to resolve potential problems thereby shortening the production time. To describe this feature refer now to the following description in conjunction with the accompanying figures. [0038] [0038]FIG. 8 illustrates issue tracking in accordance with the present invention. First an issue is provided, via step 802 . Next, the issue is raised, via step 804 . Next, the user studies issue, via step 806 . A solution to the issue is then provided, via step 808 . Next, it is determined if there are any open issues, via step 810 . If there is an open issue, then the steps 806 and 808 are repeated. If there is no open issues, then the process is ended. [0039] 7. Advantages [0040] A system and method in accordance with the present invention has many advantages. It improves manufacturing outsourcing processes for the semiconductor industry. It provides the ability to send WIP data in a “push” mechanism from the service providers to the customers using the above mentioned technologies. It provides the ability to send chip manufacturing schedule and process to all the outsourced vendors using the technologies mentioned above. It provides the ability to get lot status and progress throughout the semiconductor production lifecycle in near real-time using the above mentioned technologies. [0041] It provides the ability of service providers to send engineering & other documents, with revisions, to the customers in an automated fashion using the above mentioned technologies. [0042] It provides the ability of customers to send documents to the service providers with the project schedule using the above mentioned technologies. It provides the ability to manage issue resolution in a collaborative environment, using the peer-to-peer concept, above-mentioned technologies, specifically for semiconductor outsourcing process. [0043] It provides the ability to send Wafer Maps, WAT reports, Yield information, etc. from the service providers to the customers in a collaborative concept described above using the technologies mentioned. It provides the application of peer-to-peer technology to improve collaboration for semiconductor outsourcing processes. Finally, it provides the application of java, technology, distributed application architecture, collaborative communication platform to improve collaboration for semiconductor outsourcing processes. [0044] [0044] 8 . Conclusion [0045] A centralized and web-based project server engine allows customers to manage projects on-line under a multi-user and personalized environment. The process of locating and acquiring required services is seamlessly streamlined through the use of an integrated CMS system. Customers can use a single browser window to locate service vendors, design document sets, and other information, including standard service cycle times. During the execution of the project, status updates are automatically sent to the customers. Other important documents related to the quality of the production are also automatically sent. Upon the completion of a project design cycle, the CMS system automatically delivers the manufacturing orders through a CMS system, which automates the customers' procurement tasks. A peer-to-peer technology is utilized to ensure that the sensitive data remains with concerned parties and not sent through a centralized hub mechanism. [0046] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.	A method and system for manufacturing a supply chain collaboration is disclosed, the method and system comprising at least one customer including a first collaboration platform and at least one manufacturing partner (vendor) including a second collaboration platform. All CMS applications allow for peer-peer collaboration therebetween. A system and method in accordance with the present invention utilizes peer-to-peer technology to securely and reliably transfer the data between the companies and promotes a “push” mechanism where information is shared as soon as it becomes available.	6
BACKGROUND OF THE INVENTION This invention relates to internal tube cutters and more particularly to internal tube cutters for internally cutting tubes of nuclear steam generators. A typical nuclear steam generator comprises a vertically oriented shell, a plurality of U-shaped tubes disposed in the shell so as to form a tube bundle, a tube sheet for supporting the tubes at the ends opposite the U-like curvature, and a dividing plate that cooperates with the tube sheet forming a primary fluid inlet plenum at one end of the tube bundle and a primary fluid outlet plenum at the other end of the tube bundle. The primary fluid having been heated by circulation through the nuclear reactor core enters the steam generator through the primary fluid inlet plenum. From the primary fluid inlet plenum, the primary fluid flows upwardly through first openings in the U-tubes near the tube sheet which supports the tubes, through the U-tube curvature, downwardly through second openings in the U-tubes near the tube sheet, and into the primary fluid outlet plenum. At the same time, a secondary fluid, known as feedwater, is circulated around the U-tubes in heat transfer relationship therewith, thereby transferring heat from the primary fluid in the tubes to the secondary fluid surrounding the tubes causing a portion of the secondary fluid to be converted to steam. Since the primary fluid contains radio-active particles and is isolated from the secondary fluid by the U-tube walls and tube sheet, it is important that the U-tubes and tube sheet be maintained defect-free so that no breaks will occur in the U-tubes or in the welds between the U-tubes and the tube sheet, thus preventing contamination of the secondary fluid by the primary fluid. Occasionally it is necessary to remove one or more of the heat transfer tubes from the tube bundle. In order to remove such a tube from the tube bundle it is first necessary to deactivate the steam generator and to cut the tube internally by entering the inlet plenum of the steam generator and extending a cutter into the tube. Once the cutter has been extended into the tube, the tube may be internally cut by the cutter and subsequently removed from the steam generator. However, some of the tubes chosen to be removed may be dented at intervals along the tube such that the cutter may not be able to traverse the tube. Therefore, it is desirable to have an internal tube cutter that is capable of being inserted into and traversing a constricted tube and yet capable of proper self-alignment within the tube such that the tube is properly cut. SUMMARY OF THE INVENTION An internal tube cutter capable of being inserted into a constricted heat transfer tube of a steam generator and capable of proper self-alignment therein comprises a frame having a locking mechanism attached thereto for engaging the tube sheet of a steam generator and an extendable cutter associated with the frame with a flexible transverse positioning mechanism disposed on the cutter for positioning the cutter within the tube while being able to negotiate the constricted portions of the tube. A drive mechanism mounted on the frame is capable of rotating the cutter when the cutter is in the extended position to thereby contact and cut the internal diameter of the tube. BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the invention, it is believed the invention will be better understood from the following description taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a partial cross-sectional view in elevation of a typical steam generator; FIG. 2 is a partial cross-sectional view in elevation of the internal tube cutter attached to the tube sheet of a steam generator; FIG. 3 is a side view of the tube cutter shown in FIG. 2; FIG. 4 is an enlarged partial cross-sectional view in elevation of the lower portion of the internal tube cutter; FIG. 5 is a cross-sectional view in elevation of the cutter in the retracted position within a tube; FIG. 6 is a view along line VI--VI of FIG. 5; FIG. 7 is a partial cross-sectional view in elevation of the cutter in the extended position within a tube; and FIG. 8 is an enlarged partial cross-sectional view in elevation of the flexible transverse positioning mechanism. DESCRIPTION OF THE PREFERRED EMBODIMENT In a typical steam generator, a tube sheet supports a bundle of heat transfer tubes. Occasionally it is necessary to introduce a cutting mechanism into the tube to cut the tube so that the tube may be removed from the steam generator. The invention described herein provides an internal tube cutter that is capable of being introduced into a constricted tube of a steam generator for internally cutting the tube so that it may be removed from the steam generator. Referring to FIG. 1, a nuclear steam generator referred to generally as 20, comprises an outer shell 22 with a primary fluid inlet nozzle 24 and a primary fluid outlet nozzle 26 attached thereto near its lower end. A generally cylindrical tube sheet 28 having tube holes 30 therein is also attached to outer shell 22 near its lower end. A dividing plate 32 attached to both tube sheet 28 and outer shell 22 defines a primary fluid inlet plenum 34 and a primary fluid outlet plenum 36 in the lower end of the steam generator as is well understood in the art. Tubes 38 which are heat transfer tubes shaped with a U-like curvature are disposed within outer shell 22 and attached to tube sheet 28 by means of tube holes 30. Tubes 38 which may number about 7,000 form a tube bundle 40. In addition, a secondary fluid inlet nozzle 42 is disposed on outer shell 22 for providing a secondary fluid such as water while a steam outlet nozzle 44 is attached to the top of outer shell 22. In operation, primary fluid which may be water having been heated by circulation through the nuclear reactor core enters steam generator 20 through primary fluid inlet nozzle 24 and flows into primary fluid inlet plenum 34. From primary fluid inlet plenum 34 the primary fluid flows upwardly through the tubes 38 in tube sheet 28, up through the U-shaped curvature of tubes 38, down through tubes 38 and into primary fluid outlet plenum 36 where the primary fluid exits the steam generator through primary fluid outlet nozzle 26. While flowing through tubes 38, heat is transferred from the primary fluid to the secondary fluid which surrounds tubes 38 causing the secondary fluid to vaporize. The resulting steam then exits the steam generator through steam outlet nozzle 44. On occasion, it is necessary to remove a tube 38 from the steam generator 20 for inspection purposes. Therefore, manways 46 are provided in outer shell 22 to provide access to both primary fluid inlet plenum 34 and primary fluid outlet plenum 36 so that access may be had to the entire tube sheet 28. When it is necessary to internally cut and remove a tube 38 from the steam generator, working personnel enter manways 46 and attach an internal tube cutter (not shown) to the tube sheet so that the cutting process may be performed. Referring now to FIGS. 2 and 3, the internal tube cutter referred to generally as 48 comprises a frame 50 with locking mechanisms 52 attached thereto that are capable of being extended into the tubes 38 in the tube sheet 28. The locking mechanisms 52 may be camlocks chosen from those well known in the art. When activated, locking mechanisms 52 are capable of engaging the insides of tubes 38 thereby supporting frame 50 from tube sheet 28. An extendable cutter 54 is capable of being disposed within tube 38 and has a flexible transverse positioning mechanism 56 which may be a stainless steel wire brush attached thereto for positioning the cutter 54 within the tube 38. Flexible transverse positioning mechanism 56 is capable of negotiating the constricted portions of tube 38 while remaining centered within tube 38 at any given location, Flexible transverse positioning mechanism 56 provides the capability of allowing cutter 54 to be moved through any portion of tube 38 while maintaining the proper internal location of the cutter with respect to the tube 38. Cutter 54 is attached to a drive mechanism 58 which is mounted on frame 50. Drive mechanism 58 may be an electric motor with a right angle drive chosen from those well known in the art. Cutter 54 has a flexible elongated member 60 having one end attached thereto and having the other end extending through drive mechanism 58 and into contact with actuation mechanism 62. Referring now to FIG. 4, actuation mechanism 62 comprises two vertical poles 64 attached to frame 50 with each pole having a slidable housing 66 disposed therearound that is capable of vertically sliding along poles 64. A mounting plate 68 is horizontally attached to both housings 66. A piston-cylinder arrangement 70 is mounted on frame 50 with the piston portion attached to mounting plate 68 such that when the piston is extended mounting plate 68 along with housing 66 are lowered along vertical poles 64. On the other hand, when the piston portion of piston cylinder arrangement 70 is withdrawn into the cylinder portion mounting plate 68 is moved upwardly towards tube sheet 28 and along vertical poles 64. Piston cylinder arrangement 70 may be an air operated piston cylinder arrangement chosen from those well known in the art. Actuation mechanism 62 further comprises bearings 72 chosen from those well known in the art and mounted on mounting plate 68. A collet mechanism 74 is internally mounted on bearings 72 such that collet mechanism 74 is capable of rotating about a vertical axis which may be defined by the flexible elongated member 60. Flexible elongated member 60 extends through drive mechanism 58 and extends through collet mechanism 74 such that collet mechanism 74 may be caused to tightly contact flexible elongated member 60 when handle 76 is manually rotated. In this manner flexible elongated member 60 may be firmly attached to actuation mechanism 62. When collet mechanism 74 is firmly contacting flexible elongated member 60, activation of piston-cylinder arrangement 70 can cause mounting plate 68 to be moved downwardly thus exerting a vertically downward force on flexible elongated member 60. This vertical downward force causes cutter 54 to be extended into contact with the inside of a tube 38. Since flexible elongated member 60 is attached to cutter 54 which is attached to drive mechanism 58, the rotation of drive mechanism 58 causes cutter 54 and flexible elongated member 60 to rotate about a vertical axis defined by tube 38. Of course, since both cutter 54 and flexible elongated member 60 are both flexible, the cutting process may also take place in a curved section of a tube 38. Bearings 72 allow flexible elongated member 60 and collet mechanism 74 to rotate with respect to mounting plate 68. Thus, actuation mechanism 62 is capable of contacting flexible elongated member 60 by means of collet mechanism 74 and exerting a vertically downward force on flexible elongated member 60 even when flexible elongated member 60 is being rotated by drive mechanism 58. Actuation mechanism 62 provides a means for engaging cutter 54 so that cutter 54 may be extended into contact with the inside of a tube 38 even when drive mechanism 58 is causing the rotation of cutter 54. Referring now to FIG. 5, cutter 54 comprises a flexible shaft 78 attached to drive mechanism 58 which may be a series of metal members having rotatable ball and socket joints 80 and having a bore therein for the passage of flexible elongated member 60. Ball and socket joints 80 provide the capability of allowing flexible shaft 78 to adequately bend for insertion through manway 46 and to maneuver through curvatures in tube 38. Flexible shaft 78 has a camming surface 82 thereon which may be an inclined surface for directing cutting heads 84 into the direction of the inside of tube 38. Cutting heads 84 which may be tool steel blades are pivotally attached to bolt 86 by means of a pins 88. Bolt 86 may be a triangular shaped metal piece as shown in FIG. 6 and may be attached to metal column 90 which extends through flexible shaft 78 and is attached to flexible elongated member 60. A biasing mechanism 92 which may be a coil spring is also disposed within flexible shaft 78 and in contact with column 90 thereby exerting an upward force on column 90. When flexible elongated member 60 is drawn downwardly under the action of actuation mechanism 62, flexible elongated member 60 causes column 90 to also be drawn downwardly which being attached to bolt 86 causes cutting heads 84 to be drawn downwardly and into contact with camming surfaces 82. The contact of cutting heads 84 with camming surface 82 causes cutting heads 84 to be extended outwardly and into contact with the inside of tubes 38 as shown in FIG. 7. Energizing drive mechanism 58 causes flexible elongated member 60 to rotate about a vertical axis and causes cutting heads 84 to also rotate about a vertical axis and in contact with tube 38 thereby internally cutting tube 38. As tube 38 is cut, cutting heads 84 continue to be extended along the camming surface and further into the tube 38 thereby completely cutting the tube 38. When tube 38 has thus been severed, actuation mechanism 62 is released which allows flexible elongated member 60 to be driven upwardly by biasing mechanism 92 and then drive mechanism 58 is deenergized. Biasing mechanism 92 thus moves column 90 upwardly which causes cutting heads 84 to contact an upper portion of flexible shaft 78 and to pivot about pins 88 and back into flexible shaft 78 as shown in FIG. 5. Referring now to FIG. 8, a flexible transverse positioning mechanism 94 which may be a stainless steel wire spiral brush is mounted on flexible shaft 78 of cutter 54 and is capable of positioning cutter 54 within tube 38. Because flexible transverse positioning mechanism 94 is capable of being squeezed down as it passes through a constricted portion of tube 38 and regaining its original shape after passage through the constricted portion, flexible transverse positioning mechanism 94 is capable of aligning cutter 54 within tube 38 even in irregular shaped tubes 38. In cutting tubes 38 in an environment such as a nuclear steam generator wherein access is limited, it is important that the cutter such as cutter 54 be capable of positioning itself by means of a device such as flexible transverse positioning mechanism 94 such that the cutter is always properly positioned even though the exact transverse position of the cutter is not known to the operator. A longitudinal positioning mechanism 96 may be attached to the top of flexible shaft 78 above the location of flexible transverse positioning mechanism 94 for positioning cutter 54 along the length of tube 38 and for partially supporting the weight of internal tube cutter 48 during insertion. Longitudinal positioning mechanism 96 may comprise a lead head 98 which is removably attached to flexible shaft 78 by means of threads 100 and has an opening 102 in the top end thereof for accommodating the insertion of a flexible cable 104. The flexible cable 104 extends through opening 102 and into the interior of lead head 98. A rotatable ball 106 is bolted to the end of flexible cable 104 so that flexible cable 104 is rotatably attached to lead head 98. Since flexible cable 104 is of a much smaller diameter than cutter 54, flexible cable 104 may be threaded through the tube 38 and out the other end of tube 38 with flexible cable 104 being attached to lead head 98 such that flexible cable 104 may be pulled through tube 38 thus positioning cutter 54 within tube 38 or merely supporting the weight of internal tube cutter 48 during the insertion procedure. OPERATION When it is desired to remove a certain tube 38 from a steam generator, the steam generator is first deactivated so that working personnel may enter inlet plenum 34. Collect mechanism 74 is then tightened around flexible elongated member 60 so that cutting heads 84 are in their retracted position. At this point, flexible cable 104 is attached to ball 106 within lead head 98 and lead head 98 is threaded onto flexible shaft 78 along threads 100. Working personnel then extend flexible cable 104 through the chosen tube 38 until the flexible cable 104 exits tube 38 through outlet plenum 36 and position internal tube cutter 48 adjacent tube sheet 28 by inserting locking mechanisms 52 within tubes 38. When locking mechanisms 52 have thus been positioned within tubes 38, locking mechanisms 52 are activated which cause locking mechanisms 52 to engage the insides of tubes 38 and thus suspend frame 50 from tube sheet 28 as shown in FIG. 2. Working personnel may then pull flexible cable 104 through tube 38 until cutter 54 is located at the desired position along tube 38 while flexible transverse positioning mechanism 94 provides transverse positioning of cutter 54. Drive mechanism 58 is then activated which causes flexible elongated member 60 to be rotated and causes cutting heads 84 to be rotated. Piston-cylinder arrangement 70 is then activated which causes mounting plate 68 to be moved downwardly with respect to vertical poles 64 which cause a downward force to be exerted on flexible elongated member 60 which in turn causes column 90 to be moved downwardly. When column 90 is moved downwardly cutting heads 84 are also moved downwardly and into contact with camming surface 82 which causes cutting heads 84 to be moved outwardly and into contact with the inside of tubes 38. As cutting heads 84 cut tube 38, cutting heads 84 continue to be extended into tube 38, thereby completely cutting tube 38. When tube 38 has been entirely cut, actuation mechanism 62 is released which allows biasing mechanism 92 to cause column 90 to be moved upwardly which withdraws cutting heads 84 back into flexible shaft 78. When in this position internal tube cutter 48 may be removed from steam generator in a reverse manner in which it was placed therein. This procedure may then be performed on other tubes within the steam generator so that other tubes may thus be cut. Therefore, the invention provides an internal tube cutter which is capable of being placed within a tube having constrictions while the cutter is appropriately spaced within the tube for cutting the tube.	An internal tube cutter for cutting the inside of tubes of a nuclear steam generator comprises an extendable cutter capable of being disposed within a tube of a steam generator along with a flexible transverse positioning mechanism disposed on the cutter for positioning the cutter within the tube. The cutter is attached to a drive mechanism that is capable of rotating the cutter when the cutter is in an extended position to thereby cut the inside of the tube. The cutter and flexible transverse positioning mechanism are capable of being inserted into and traversing through tubes whose inside diameter is severely reduced due to denting while being capable of being extended and severing the tube at a section of the tube having a normal diameter.	8
VEHICLE HORN FIELD OF THE INVENTION The present invention pertains to the field of vehicle horns, and in particular to air and gas horns which are typically mounted on the exterior of commercial vehicles. BACKGROUND OF THE INVENTION Heavy duty trucks and boats, as well as other vehicles, often carry air or gas powered horns on the surface of their roof, fender or deck. The horns are typically bolted on the surface and directed forward to deliver a powerful warning to those in danger of colliding with the heavy truck or boat. Typically, these horns have a rear sound unit which connects to a long bell, measuring sometimes in excess of 36 inches (1 meter) long which opens at a flared end. The bell is bolted to the vehicle pointing forward so that its warning blast is best heard by those in front of the vehicle. Because the bell is pointed forwards as the vehicle moves, the bell tends to collect debris including not only snow and rain, but also insects, sand and dirt which have been kicked up into the air in front of the vehicle as it travels. While it is known to put a metal cover over the front of a heavy duty truck air horn, these guards reflect most of the sound coming out of the horn backwards, making it difficult for those in front of the truck to hear the warning blast. It is also known as shown in U.S. Pat. No. 4,171,678, to place a weather shield over the front of a heavy duty truck horn with slots in it to allow sound to project forwards. However, these slots also allow debris to enter the horn. Conventional air horns also have other problems. First, because of the length of the bells, most air horns are difficult to ship and store, before they are mounted on the vehicle. Second, when the horn is bolted to the surface of the vehicle, it is difficult to remove and repair or replace. For example, bolts must often be loosened from the underside of the surface to which the horn is applied, requiring interior parts to be temporarily removed. Thus, long horns are typically made in two parts with the front bell section welded, soldered or brazed to the rear section. Attaching the two sections is costly. SUMMARY OF THE INVENTION The invention provides a weather shield, which allows sound to project both frontwards and backwards from the end of a vehicle horn bell. It also prevents debris from entering the horn bell and prevents debris from accumulating behind the shield. In one embodiment, the invention is a shield for a vehicle horn bell mouth, having a front wall adapted to extend across the bell mouth and beyond the mouth periphery, spaced apart from the bell mouth. The shield allows sound from the bell mouth to travel beyond the mouth periphery and has a sound opening in the front wall adapted to be outside the mouth periphery, to allow sound traveling beyond the mouth periphery to travel out the sound opening. The sound opening is adapted to direct sound in a forwards direction with respect to the vehicle. A rear opening is aligned with the front sound opening to allow debris entering the front sound opening to exit through the rear sound opening. The shield includes a side wall which extends from the edge of the front wall and the bell mouth, preferably along the entire perimeter of the front wall and beyond the mouth periphery. This side wall may have a cutout to allow debris collected in the space between the bell and the shield to fall through the cutout, out of the space. The invention also encompasses a vehicle horn having a bell mouth adapted to be mounted facing a forward direction with respect to a vehicle, and a shield with a front wall spaced apart from the bell mouth extending across and in front of the bell mouth beyond the bell mouth periphery. The shield has a sound opening in the front wall beyond the bell mouth periphery for allowing sound to travel forwards from the bell mouth out the sound opening. Preferably, the shield defines a rear opening between the shield and the bell mouth periphery for allowing sound to travel backwards from the bell mouth out the rear sound opening. A side wall may extend rearward from the front wall perimeter to shield the space between the bell mouth and the front wall. A rear opening between the side wall and the bell mouth periphery aligned with the front opening allows debris which enters the sound opening to exit through the rear opening. The sound openings on the front wall preferably are slots on opposite sides of the front wall, and the front wall includes a sound guide for directing sound from the bell mouth to the sound opening. In one embodiment, the present invention provides a two part vehicle air horn bell which can be easily assembled and easily removed from the vehicle, making the horn easier to ship, install and service. In this embodiment, the vehicle horn has a first bell section with an opening at one end and a second bell section with an opening at an end facing the first section end and a clamp adapted to receive the first and second bell section ends and hold the openings facing each other, to form a continuous sound passage between the first and second bell sections. Preferably, the first and second bell section ends have flanges which extend outward from their central axes and butt against each other on respective surfaces when held in the clamp. The clamp preferably has a first collar portion extending around one part of the first and second bell section ends and a second collar portion extending around another part of the first and second bell section ends connecting to the first collar portion. Preferably, the collar portions have an inner groove for receiving and retaining the first and second bell section flanges. The clamp also preferably includes a pedestal for supporting the horn on a surface. The present invention allows a vehicle air horn to be quickly and conveniently removed and replaced on the surface of a vehicle without removing bolts and without manipulating bolts on the underside of the vehicle's surface. In such an embodiment, the invention encompasses a method for mounting a horn on a vehicle, which involves fastening a rear mounting base to the vehicle and then sliding a horn having a rear mounting surface into engagement with the vehicle, so that the rear mounting surface engages the rear mounting base. Preferably, the method includes sliding a front pedestal on the horn into engagement with the vehicle, at the same time as sliding the rear mounting surface into engagement, so that, when engaged, the horn is supported by both the rear mounting base and the pedestal. Preferably, sliding a horn having a rear mounting surface comprises sliding mating, elongated and converging surfaces towards each other until the surfaces meet. In one embodiment, this involves sliding elongated and converging ribs, into a mating, elongated and converging channel until the ribs butt against the channel. The invention also encompasses a vehicle mounting assembly for a vehicle horn with a rear mounting base fastenable to a vehicle surface and a rear mounting surface connected to the horn for slidably engaging the rear mounting base. The rear mounting base and rear mounting surface preferably have elongated and converging surfaces which butt against each other for engagement. These surfaces include elongated and converging ribs and an elongated and converging channel, so that the ribs butt against the channel for engagement. The invention also comprises a pedestal for slidably engaging the horn with the vehicle surface when the rear mounting surface is slidably engaged with the rear mounting base. The pedestal has a collar for supporting the horn's bell and a foot fastenable to the vehicle's surface. The foot has spaced apart adjacent fingers for receiving a bolt within a space between the fingers. The rear mounting base and the pedestal are adapted to be slidably engaged when the horn reaches the rearward limit of its travel with respect to the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a horn for attachment to a vehicle surface according to the present invention; FIG. 2 is an exploded side view of bell sections and a partially cross-sectional view of a clamp for fastening the bell sections together and for attachment to a vehicle surface according to the present invention; FIG. 3 is an exploded front elevational view of the clamp of FIG. 2; FIG. 4 is a side elevation partially cut away view of the apparatus of FIG. 2 assembled showing the upper part of the clamp in cross section; FIG. 5 is a side elevational view of a horn according to the present invention showing how it is mounted to a vehicle surface; FIG. 6, including FIGS. 6A and 6B, is a top elevational view of a rear mounting base and a bottom elevational view of a rear mounting surface according to the present invention; FIG. 7, including FIGS. 7A and 7B, is a rear elevational view of the rear mounting base and the rear mounting surface shown in FIG. 6; FIG. 8 is a top elevational view of the clamp of FIGS. 2, 3 and 4 fastened to a surface by a mounting bolt; FIG. 9A is a front elevational view of the horn of FIG. 1; FIG. 9B is a front elevational view of the horn of FIG. 1 with the shield removed; FIG. 9C is a front elevational view of the horn of FIG. 1 showing the bell of FIG. 9B in broken lines; FIG. 10 is a rear elevational view of the horn of FIG. 1; FIG. 11 is a bottom elevational view of the horn of FIG. 1; FIG. 12 is a top elevational view of the horn of FIG. 1; and FIG. 13 is a rear elevational view of a shield removed from the bell. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle horn suitable for use on light, medium and heavy duty trucks, boats and other vehicles. As shown in FIG. 1, at the rear end of the horn is a conventional sound unit 10 which can be driven electrically or by air pressure, and preferably vibrates a diaphragm to create sound pressure air waves that travel forwards from the sound unit. These sound waves travel through a bell 12 to a shield 14. The air horn is typically mounted on a vehicle facing forwards so that sound generated in the sound unit 10 is projected forwards through the bell directly to those in front of the vehicle. Since the open end of the horn's bell faces forwards, airborne debris tend to move towards the open end of the horn's bell as the vehicle travels. This debris is blocked by the shield 14. The horn's bell is divided into two sections. The first section is the tube 16 which extends from the sound unit 10 to a clamp 18. The tube's diameter increases slowly as it nears the clamp. The second section 20 is the flare which increases diameter at a much greater rate than the tube section and extends from the clamp 18 to the end of the bell, which is partially obscured in FIG. 1 by the shield 14. The air horn is fastened to the truck using a rear mounting base 22 and a front pedestal 24 which are bolted onto the surface of the vehicle as described below. The pedestal 24 supports and is preferably connected to the clamp 18. The horn bell is preferably chrome plated brass, but other materials can be used. At the end of both the tube section and the flare section there is a flange 26, 28 as shown in FIG. 2. Both flanges have the same diameter and flat ring-shaped ends so that when they are placed against each other, a continuous smooth channel is formed for sound traveling through the bell. The flanges are designed to fit into the clamp 18. The clamp has a collar 29 which completely surrounds the bell, as best seen in FIG. 3. Both the semi-circular top portion of the collar 29a and the semi-circular bottom portion of the collar 29b have a groove 30, the shape of which matches the outer periphery of the flanges 26 and 28. As a result, when the tube sections are butted against each other, the two collar portions can be closed together to encircle the ends of the bell sections and hold the two bell sections securely in place. As best seen in FIGS. 1 and 3, the two collar portions are held together with machine screws 32, which extend through the top collar portion 29a into the bottom collar portion 29b. Since the flanges extend outwards from the central axis of the bell, there is no constriction in the bell where the two bell sections met. In addition, the bell sections cannot be removed from the clamp when the two collar portions are connected together. The two sections are accordingly held tightly and firmly together without solder or brazing. Although solder may be used to strengthen the connection, this hampers disassembly. A variety of arrangements are possible for the groove 30 of the clamp, and it is not necessary that the two bell sections butt against each other when the clamp is connected. For example, the clamp could hold the two bell sections apart from each other and bridge the gap between the two bell sections. The present arrangement is preferred to minimize vibration and to maximize strength of the assembled parts. Since the flange is angled outwards and it matches the angle of the groove in the collars, as the top and bottom collar portions are screwed down together, the outside surface of the flanges slide against the surface of the groove until the two bell sections are wedged against each other in the groove, around their entire perimeters. This helps reduce vibration. When the flanges butt against each other, the collars are fully tightened and the assembly of the bell is complete. While the flares shown in the drawings are preferred, a variety of other tube ends may be used instead. The tubes may be straight, have flat rims or curve inwards, for example. Constructing a bell in two parts is valuable not only to reduce shipping costs and make parts easier to store, but it also can significantly reduce manufacturing costs. It is at present costly to manufacture a one piece bell with the significant length required and the substantial flare at the end. Frequently, air horns are made by taking a straight tube, which has been swaged out at one end and joining it to a die cast flare section. Air horn bells presently on the market commonly have a seam where the two bell sections have been soldered or brazed together. Brazing the pieces together is expensive and time consuming. The bells are often chrome plated or painted to help cover the seam. The seam between the bell sections is also a weak point in the horn. Constructing the two bell sections in two pieces and holding them together with a clamp eliminates this weak point and substitutes the strength of the clamp for the weakness of the seam. It also allows the horn to be repaired in parts. If there is an injury to the bell's flare, the flare section can be removed and replaced without affecting the tube section, for example. For particularly long horns, the bell can be built in three or more sections and two or more clamps are then used as necessary. In addition to being easily assembled, the horn of the present invention is also easily and quickly installed on a vehicle. As shown in FIG. 5, to mount the horn, a rear mounting base 34 is first fastened to the vehicle surface 35, for example the roof of a heavy truck. Then a mounting bolt 36 is connected forward of the rear mounting base. The horn is installed onto the rear mounting base and the bolt by sliding a rear mounting surface 38, preferably connected to or a part of the sound unit 10 of the horn, into the rear mounting base while sliding a foot 40 of the horn's pedestal 24 around the front bolt. When the horn reaches the limit of its rearward travel into the rear mounting base and around the mounting bolt, the mounting bolt 36 is screwed down against the foot of the pedestal and the horn is securely locked in place. To remove the horn, the mounting bolt is simply loosened and the horn is slid forwards out of its mounts. As a result, once the rear mounting base and the mounting bolt have been installed, the horn can be very quickly removed and replaced or serviced. An antitheft or locking bolt can be used for the mounting bolt, if desired, to make the horn a little more difficult to remove. The rear mounting base 34, as shown in FIGS. 6 and 7, has a set of bolt holes 42 for fastening the base to the surface of the vehicle. Any type of fastening method may be used, however, bolts are presently preferred. It also has a raised dove-tailed surface 44 extending above the bottom portion of the base. This surface has elongated ribs 46 which converge towards the front of the rear mounting base. The sound unit 10 has a mounting surface 48 in the form of a channel, which is adapted to mate with the mounting surface of the rear mounting base. As shown in FIG. 6, the channel 48 is also elongated and converges towards the front of the sound unit. This allows the two elongated and converging surfaces to be inserted one into the other until the ribs 46 butt against the converging elongated channel 48, engaging the rear mounting base with the horn's rear mounting surface. As best seen in FIG. 7, the surfaces are not only elongated and converging, but also angled inwardly to form mutually interfering surfaces so that the sound unit cannot be pulled vertically up from the rear mounting base once it is installed. While the horn is illustrated with the channel in the sound unit and the mounting surface on the mounting base, these positions can be reversed with no loss in utility. In addition, the horn's mating surface can be located elsewhere on the horn or formed in some other manner if desired. The pedestal foot 40 is similarly designed to lock into place around and under the mounting bolt 36. FIG. 8 shows the pedestal as viewed from the top. The pedestal has a foot 40 which has two spaced apart elongated fingers 52. These fingers define a slot 54 between them which receives the mounting bolt 36. The head of the mounting bolt extends over the tops of the fingers so that by tightening the mounting bolt against the vehicle surface, the fingers are clamped against the vehicle surface and the horn is held securely in place. If the mounting bolt were not tightened, the air horn could be quickly removed simply by sliding it forwards with respect to the vehicle. This could occur inadvertently when braking, for example, so the mounting bolt is important to hold the air horn to the vehicle. A variety of other sliding fastening devices may be used within the scope of the present invention. A dove-tailed mounting arrangement similar to the rear bracket, for example, could be used to hold the front pedestal in place. In addition, the front mount or the rear mount can be eliminated altogether. It is common for horns with short bells to use only a rear mounting. For longer horns, more than two mounts can be used. It is at present well known to use an open collar as a pedestal for the front end of an air horn. The collar forms approximately a three-quarter circle so that a narrow part of the tube section of the bell can be passed through the opening in the collar. The air horn can then be drawn backwards so that as the bell flares outwards it is wedged tight against the collar. This type of collar can be combined with the rear mounting arrangement of FIGS. 6 and 7 in place of the clamp shown so that the air horn is wedged into position in the front open collar and into the rear mounting base at the same time. Again, however, it is preferred that some device to prevent the inner horn from moving forwards be used. The present invention includes a shield 14, shown in FIG. 9A, to prevent foreign debris from accumulating within the bell of the air horn. The shield fits over the end of the bell 20 shown in FIG. 9B. The bell has an opening 60 from which the sound generated by the sound unit 10 emanates. Around the perimeter of this opening is an end plate 62, which is preferably flat. The opening 60 and the end plate 62 together constitute the mouth of the bell. While it is presently preferred that the bell end in a round opening surrounded by a rectangular end plate, the bell can also be constructed to end in a rectangular opening with or without an end plate, or to end in a round opening with or without a round or square end plate. An end plate is presently preferred, in part because it prevents some debris from entering the bell mouth and it provides a secure mounting location for the shield. The shield 14 has a front wall 64 which extends across the opening of the bell 60 and preferably across the entire bell mouth, including the end plate 62 as indicated in FIG. 9C. This front wall is the obstacle to debris, which would otherwise enter into the bell opening 60. Beyond the perimeter of the bell mouth are two sound openings 66, in the form of slots on opposite sides of the shield's front wall from each other. The inside surface of the front wall of the shield 64 is spaced apart from the end plate 62, as shown in FIG. 11, so that sound emanating from the opening 60 is trapped in the space 63, between the wall 64 and the plate 62 and is forced to the sides, where it can then travel out the slots 66 on either side of the bell opening 60. These slots allow a large portion of the sound to travel forwards so that the warning blast from the air horn is sent to those directly in front of the vehicle. As shown in FIGS. 9C and 10, the slots are placed beyond the perimeter of the bell mouth (60 and 62) so that any debris which enters the slots does not meet the bell mouth. As shown in FIG. 10, the outside edge of the shield 14 is wider than the end plate 62, so that there is a space 67 between the perimeter or edge of the shield and the perimeter or edge of the end plate 62. This allows the openings or slots 66 to be completely beyond the end plate 62. Any debris which enters the slots is allowed to pass directly through the space 67 between the edge of the end plate and the shield, instead of being forced into the horn's bell. As shown in FIGS. 11 and 12, the front wall 64 is surrounded by a side wall 68 which extends around the entire perimeter of the front wall backwards past the bell mouth. This side wall not only prevents debris from entering into the space between the front surface and the bell end plate, it also serves to help channel the sound coming out of the bell. Rather than being directed sideways, the sound is forced to either come forwards through the slots or rearward through the space between the side surface and the end plate. Since, as shown in FIGS. 9C and 10, there is a space 67 between the side wall 68 and the end plate all the way around the end plate, the shield projects a large amount of the horn's sound backwards. The proportion of sound projecting backwards or forwards can be varied by altering the relative sizes of the front and rear sound openings. FIG. 11 also shows a cutout 70 in the bottom of the shield which allows any debris which has accumulated in the space between the end plate and the shield or in the flare of the bell, to fall downwards and out the cutout. This is particularly important for condensation and moisture, however, it also serves as a last chance for debris to exit before it enters the horn. As shown in FIG. 13, the inside surface of the front wall of the shield 14 includes a groove 72 that extends from one slot 66 to the other. This groove helps direct and guide sound emanating from the opening in the bell across the inside surface of the shield 14 towards the openings in the shield. This helps increase the amount of sound which emanates from the slot forwards over the amount which is directed backwards out the rear openings. While a rectangular shield and bell mouth have been shown in the embodiments above, any other shape including square, oval or round may also be used. The sizes, shapes and locations of the sound openings can be varied to change the appearance and performance of the horn. The elongated groove can assume different forms to conform to different slot arrangements or be removed altogether. While only a few variations have been shown and described above, the inventor intends in no way to abandon the many variations and modifications within the spirit and scope of the present invention.	A vehicle horn has a shield which covers the mouth of the horn's bell to prevent debris from entering the bell. A front sound opening beyond the bell mouth perimeter allows sound to project forwards while still protecting the bell and a rear sound opening aligned with the front sound opening allows debris to pass through both openings without collecting within the space between the bell mouth and the shield. A side surface shields that space and includes a bottom cutout which allows any debris collected to fall out of the space. A vehicle horn has a bell constructed of two tubular sections, the end of each section having a mating flange which fits into a specially adapted clamp. As the clamp is tightened, the tube sections are drawn together until they butt against each other. The clamp is tightened by securing mating collar portions against each other. A pedestal and a rear mounting base are used to connect the horn to a vehicle. The rear mounting base and a mounting bolt are connected to the vehicle. The horn has a pedestal for supporting its bell with a foot that slides around the mounting bolt and a rear mounting surface that slides onto the rear mounting base. These allow the horn to slide into engagement with the vehicle.	6
FIELD The present disclosure relates generally to projectiles, and more particularly to a system and method for controlling flight of a spinning projectile. BACKGROUND The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. There presently is increasing interest in being able to control the trajectory of projectiles while same are in flight. For example, there is significant interest in being able to control the trajectory of a large caliber bullet, for example a .50 caliber bullet fired from a rifle or automatic weapon. It is known that as a bullet leaves the weapon from which it is fired, it will have a high rate of spin. Typically a .50 caliber bullet may be spinning at or above about 150,000 rpm as it moves through the atmosphere and is nearly constant throughout the flight. With a spinning bullet, the use of fins to modify its flight trajectory after it leaves the weapon is not a viable option for controlling the flight of the spinning bullet. This is because the fins must respond to the complex airflow at an extremely high rate of speed, which can not be supported by available actuation technology. Some control scheme and/or method for controlling the orientation of the nose of the bullet during its flight would enable the trajectory of the bullet to be controlled to a higher degree of accuracy. SUMMARY In one aspect the present disclosure relates to a method for controlling a flight trajectory of a spinning projectile. The method may comprise supporting a nose of the projectile in a manner permitting the nose to be wobbled; coupling at least one electrically responsive component at a first end to the nose and at a second end to a base portion of the projectile; sensing a rate of spin of the projectile as the projectile flies through an atmosphere after being fired from a weapon; and controllably applying an electrical signal to the electrically responsive component, in relation to the sensed rate of spin, to control an attitude of the nose during flight of the projectile. In another aspect a method is disclosed for controlling a flight trajectory of a spinning projectile. The method may comprise supporting a nose of the projectile in a manner permitting the nose to be wobbled; supporting the nose by a plurality of circumferentially spaced apart, electrically responsive components; detecting when the projectile has been fired from a weapon; sensing an angular position of the nose and a rate of spin of the projectile as the projectile flies through an atmosphere after being fired from the weapon; and controllably applying electrical signals having different phases to the plurality of electrically responsive components, in relation to the sensed angular position of the nose, to control an attitude of the nose during flight of the projectile. In still another aspect of the present disclosure a system is disclosed for controlling a flight trajectory of a spinning projectile. The system may comprise a projectile having a nose and a body portion, with the nose portion being supported for movement relative to the body; a plurality of electrically responsive components coupled between the nose and the body portion; and a subsystem that senses an angular position of the nose after the projectile has been fired from a weapon and generates electrical signals that are applied to the electrically responsive components to counteract the wobbling motion to maintain the nose in a relatively constant, desired attitude during flight of the projectile. Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. FIG. 1 is a perspective exploded view of a projectile in accordance with one embodiment of the present disclosure; FIG. 2 is an end, showing the orientation of the three electrically responsive components that are coupled to the nose of the projectile; FIG. 3 is a side view of the projectile of FIG. 2 ; FIG. 4 is a block diagram of the electronic subsystem of the system along with other components that may be used by the system; FIGS. 5A-5C are waveforms illustrating the phase differences between exemplary switching signals that may be applied to each of the piezoceramic actuators; and FIG. 6 is a flowchart of operations performed by the system in controlling the attitude of the nose of the projectile during its flight. DETAILED DESCRIPTION The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. Referring to FIG. 1 , there is shown a system 10 for changing the angle of a nose of a bullet, relative to the body, while the bullet is in flight to control the trajectory of the bullet. In general, the nose of the bullet is rotated in accordance with a generally constant nose angle, smoothly relative to the bullet body, with a rotation rate equal to but in opposite direction as the rotation rate of the bullet. This enables the bullet to appear to have a bent nose that is constant in its orientation relative to an air stream through which it flies, and thus can be used to control the trajectory of the bullet after it leaves the barrel of a weapon. In FIG. 1 , the system 10 involves the use of a projectile 12 having a body portion 14 , a nose 16 , and a reduced diameter portion 18 for supporting the nose 16 from the body portion 14 . The reduced diameter portion 18 is preferably made from a material that is slightly flexible, such as high strength steel. An electronic subsystem 22 is located within a central portion 20 of the body portion 14 for controlling a wobbling motion (i.e., deflection) of the nose 16 as the projectile 12 is in flight. In one form the projectile 12 may comprise a bullet, for example a .50 caliber round of ammunition that is fired from a rifle, automatic weapon, or any other suitable weapon. The system 10 is not limited to use with any one caliber of projectile, but rather may be incorporated into larger or smaller caliber projectiles. However, with the long useable range of a .50 caliber bullet, which may extend for one mile or longer, the accuracy provided by the present system 10 is expected to significantly enhance the effectiveness of such a projectile and its corresponding weapon. The projectile 12 may be substantially enclosed within a conventional casing 23 before being fired from a weapon 25 . With further reference to FIG. 1 , the nose 16 is also supported by three electrically responsive components 24 a , 24 b and 24 c . In one embodiment the electrically responsive components 24 a - 24 c may comprise piezoceramic actuators, however, any form of electrically responsive materials may be used, provided they have the ability to alter their shape in response to an electrical signal. For convenience, the electrically responsive components 24 a - 24 c will be referred to throughout the following discussion simply as “piezoceramic actuators” 24 a - 24 c. The piezoceramic actuators 24 a - 24 c each may be shaped like a beam. Each is further coupled at a first end 26 to an associated coupling element 28 , and at a second end 30 to a coupling element 32 . The coupling elements 28 and 30 are fixedly secured either by suitable adhesives or mechanical fasteners to the nose 16 and body portion 14 respectively. As shown in FIG. 2 , the piezoceramic actuators 24 a - 24 c are further arranged so that they spaced apart preferably about 120 degrees from one another around the circumference of the nose 16 . As will be described in more detail in the following paragraphs, the piezoceramic actuators 24 a - 24 c are controllably actuated to cause the nose 16 to be tilted (or deflected) away from the axial center 34 of the projectile 12 during flight. This is highly useful in controlling the trajectory of the projectile 12 . As will be appreciated, a projectile such as a bullet typically exits the barrel of the weapon from which it was fired with a high degree of spin. The rate of spin may be up to 15,000 rpm or even higher. Typically the nose of a bullet will begin to “wobble” slightly as it flies through the atmosphere after leaving the barrel. By “wobble”, it is meant that the axial center of the nose of the bullet moves through and around the generally linear path that the bullet is travelling. As the bullet travels towards its intended target the amount of wobble of the nose typically gets worse. Depending on the distance to the target and the atmospheric conditions present, such as wind, rain, snow, etc., the wobble may become significantly pronounced. Eventually, the bullet may actually begin tumbling end over end before it reaches its intended target. Obviously, the greater the degree of wobble of the nose during flight, generally the greater the loss of accuracy of the bullet that will be experienced. With brief reference to FIG. 3 , for example, when piezoceramic actuator 24 a is actuated, it bows or “buckles”, causing it to pull the nose 16 of the projectile 12 away from the axial center 34 of the projectile 12 . Depending which one piezoceramic actuator 24 (or pair of actuators 24 ) is actuated, the nose 16 will be deflected in an intended direction. This controlled deflection or controlled wobble of the nose 16 is used to effectively cancel the wobble that the nose 16 of the projectile 12 would otherwise experience during flight if the piezoceramic actuators 24 a - 24 c were not being used. Selectively actuating specific ones of the piezoceramic actuators 24 a - 24 c allows the nose 16 of the projectile to be kept in a constant orientation, relative to a reference surface (e.g., a ground surface). This can significantly enhance the accuracy of the projectile 12 . It will also be appreciated that while the piezoceramic actuators 24 a - 24 c are shown in linear orientations in FIGS. 1 and 2 , that the actuators could just as readily be configured so that they assume a normally bowed or buckled shape. Then, straightening out any given one of the piezoceramic actuators 24 a - 24 c , either by applying a suitable electrical signal or removing an electrical signal, could achieve the desired deflection of the nose 16 described above. It will also be appreciated that while three piezoceramic actuators 24 a - 24 c are illustrated, that a greater or lesser plurality of actuators could be employed. The number of piezoceramic actuators 24 used will affect the degree of precision by which the nose 16 can be deflected. However, the greater the number of actuators 24 used the greater the complexity and cost of the signal processing electronics that will likely be required. Referring now to FIG. 4 , a more detailed illustration of one embodiment of the electronic subsystem 22 of the system 10 is shown. Initially, it will be appreciated that the system 10 includes an external signal source 36 for supplying a wireless signal that may be used by the system 10 in implementing control of the piezoceramic actuators 24 a - 24 c . The wireless signal is preferably an electromagnetic wave signal (e.g., an RF signal). A projectile launch sensor 38 is physically attached to the weapon that is used to fire the projectile 12 so that the recoil of the weapon can be sensed, and the approximate instant that firing occurs can be detected. The launch sensor 38 may be a strain gauge or any other suitable form of sensor, for example a sensor formed from a piezoelectric polymer such as a polyvinylidene fluoride (PVDF). Such a sensor is commercially available from Ktech Corporation of Albuquerque, N. Mex. Alternatively it be an electrically isolated section of the piezoceramic material or the bimorph beam itself which is able to detect the firing (i.e., recoil) of the projectile. The electronic subsystem 22 includes an antenna, which is also shown in FIG. 3 . The antenna, as shown in FIG. 3 , is preferably orientated perpendicular to the axial center of the projectile 12 . The signal being emitted from the external signal source 36 may be a polarized signal, for example a vertically polarized signal. Thus, the strength of the signal received by the antenna 40 will vary significantly, and in a cyclic manner, as the physical orientation of the projectile 12 changes when the projectile spins during flight. This is because the physical orientation of the antenna 40 will be continuously changing such that a signal of increasing strength, and then decreasing strength, will be received, in an alternating fashion. The frequency of the cyclic signal will also be in accordance with the spin rate of the projectile 12 . The antenna 40 may comprise a patch antenna that is linearly polarized. Alternatively, a magnetic sensor may be used in place of the antenna 40 and external RF signal 36 . The magnetic sensor may sense the Earth's magnetic field as it spins and the sensor may generate a sinusoidally varying output waveform that is referenced to the spin rate, and also to the roll angle, of the projectile 12 . The electronic subsystem 22 may include a roll angle reference oscillator 42 , a phase lock loop subsystem 44 , a flight control processor 46 , a nose angle sensor 48 , a three phase signal generator 50 , an amplitude control subsystem 52 , an acceleration command generator 54 and an actuator drive subsystem 56 . The roll angle reference oscillator 42 receives the varying output signal from the antenna 40 and the launch signal from the launch sensor 38 . Upon receiving the launch signal, the roll angle reference oscillator 42 begins generating a sinusoidally varying (i.e., oscillating) reference signal having a frequency that is tied to the spin rate of the projectile 12 , and which is also indicative of the roll angle of the projectile 12 . Thus, if the spin rate of the projectile 12 as the projectile leaves the weapon is 150,000 rpm, then the frequency of the output signal from the roll angle reference oscillator 42 may be 2.5 Khz. Also, since one revolution of the projectile 12 will represent one cycle of the oscillator's 42 signal, this sinusoidal signal forms a measure of the projectile roll angle at any given instant. The nose angle sensor 48 supplies signals relating to the angle of the nose wobble at any given instant to the flight control processor 46 . One implementation is to electrically isolate a small section of the piezoceramic material located on each piezoceramic actuator 24 , thus forming a strain sensor that measures the deflection of the piezoceramic actuator 24 , and hence the angle between the nose 16 and the bullet body portion 14 . The angle of wobble of the nose 16 of the projectile 12 is relative to the axial center of the body portion 14 . The output of the roll angle reference oscillator 42 is fed to an input of the phase lock loop (PLL) subsystem 44 . The PLL subsystem 44 also receives an output from the flight control processor 46 and from the actuator drive subsystem 54 . The flight control processor 46 provides the phase offset commands that are used by the PLL subsystem 44 to generate the needed phase control signals to the three phase signal generator 50 . Put differently, the signal output from the flight control processor 46 represents the desired phase difference (i.e., offset), at a given time, between the phase angle of the sinusoidal output from the roll angle reference oscillator 42 and the projectile nose wobble output from the nose angle sensor 48 . Essentially, the flight control processor 46 provides an input signal to the PLL subsystem 44 that tells the PLL subsystem what is the offset phase of the electrical signals that that need to be generated to offset the wobble of the nose 16 and to maintain the nose at a desired angle relative to a reference surface. For example, in FIG. 3 , the desired angle 34 a of the nose 16 may be preselected to be 20 degrees. The flight control processor 46 would then be programmed to provide the offset needed to maintain the nose at the desired 20 degree angle. The precise angle selected may depend on various factors, including the type of projectile (e.g., caliber) being used, or possibly even the environment in which the projectile is being used (e.g., in windy, rainy weather). An option is a remote flight control processor 46 a . A remote flight control processor would receive wireless signals, for example wireless RF signals, from the nose angle sensor 48 and the acceleration command generator 54 , and send wireless phase offset signals back to the PLL subsystem 44 to control angular orientation of the nose 16 of the projectile 12 . The remote flight control processor 46 a could be located on a mobile platform or at a stationary location, such as a nearby command facility. Returning to FIG. 4 , the PLL subsystem 44 generates the phase control signals that the three phase signal generator 50 uses to generate the three phase electrical signals that are used for controlling the piezoceramic actuators 24 a - 24 c . The output signals from the three phase signal generator 50 are modified by the amplitude control subsystem 52 , based on the desired normal acceleration of the nose 16 . The amplitude control subsystem 52 output signals may be generated by a suitable guidance algorithm used therewith. Thus, when the acceleration of the projectile 12 is at a maximum value, and the wobble of the nose 16 is expected to be at its lowest magnitude, the acceleration command generator may not attenuate the signals output from the three phase signal generator 50 at all. But as the projectile 12 flies along it path of travel, the acceleration command generator 54 may signal to the amplitude control subsystem 52 to slightly increase the magnitudes of the output signals being provided to the actuator drive subsystem 56 . This allows the amplitude of the drive signals to be tailored to the speed of the projectile 12 . Referring further to FIG. 4 , the actuator drive subsystem 56 can be seen to include switching elements 58 a , 58 b , 60 a , 60 b , and 62 a - 62 b . An inductor 64 is disposed between the two switching elements 58 a and 58 b . A second inductor 66 is disposed between the two switching elements 60 a and 60 b , and a third inductor 68 is disposed between the switching elements 62 a and 62 b . The inductors 64 , 66 and 68 take the switching signals from the amplitude control subsystem 52 and help to provide sinusoidal electrical switching signals to the piezoceramic actuators 24 a - 24 c . The output signals from the amplitude control subsystem 52 control the switches associated with each of the piezoceramic actuators 24 a - 24 c . In effect, the switching signals applied to the switches 60 a , 60 b will be 120 degrees out of phase (e.g., advanced), from those applied to switches 58 a , 58 b . The signals applied to switches 62 a , 62 b will be 120 out of phase (e.g., advanced) from those applied to switches 60 a , 60 b . Referring briefly to FIGS. 5A-5C , one example of the switching signals is shown. Switching signal 70 may be applied to piezoceramic actuator 24 a , switching signal 72 to piezoceramic actuator 24 b and switching signal 74 to piezoceramic actuator 24 c . Signal 72 is advanced 120 degrees in phase from signal 70 , and signal 74 is advanced 120 degrees in phase from signal 72 . Referring to FIG. 6 , a flowchart 100 is shown illustrating exemplary operations that the system 10 may perform in controlling the flight of the projectile 12 . Initially, at operation 102 , the launch of the projectile 12 is first detected. At operation 104 the roll angle and spin rate of the projectile 12 is sensed. At operation 106 the roll angle and spin rate are used by the roll angle reference oscillator 42 to generate the roll angle reference signal. At operation 108 the needed flight control information is obtained from the flight control processor 46 . At operation 110 the PLL subsystem 44 generates the PLL signals that are used by the three phase signal generator 50 . At operation 112 the magnitudes of the three phase switching signals from the three phase signal generator 50 are adjusted in relation to the acceleration of the projectile 16 . At operation 114 the amplitude adjusted switching signals are applied to the piezoceramic actuators 24 a - 24 c. The system 10 and method of the present disclosure enables the attitude of the nose of a projectile to be maintained at a desired attitude over the course of its flight, relative to some external reference line, for example a ground surface, over which the projectile is travelling. This can significantly increase the accuracy of the projectile. While various embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the present disclosure. The examples illustrate the various embodiments and are not intended to limit the present disclosure. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.	A method is disclosed for controlling a flight trajectory of a spinning projectile. In one aspect the method may involve supporting a nose of the projectile in a manner permitting the nose to be wobbled. At least one electrically responsive component may be coupled at a first end to the nose and at a second end to a base portion of the projectile. An angular position of the nose of the projectile may be sensed as the projectile flies through an atmosphere after being fired from a weapon. An electrical signal is controllably applied to the electrically responsive component, in relation to the sensed angular position of the nose, to control an attitude of the nose during flight of the projectile.	6
FIELD OF THE INVENTION The present invention relates to a composite-construction roll, including a roll frame reinforced with reinforcing fibers, the reinforcing fibers are arranged in a spiral inside the matrix material. The invention also relates to a method for manufacturing a composite-construction roll and to a special use of the roll. BACKGROUND OF THE INVENTION European patent publication 363887 discloses one method for manufacturing a composite-construction roll. Generally, such a roll is manufactured on top of a suitable form by winding reinforcing fibers spirally around the form and simultaneously feeding the matrix material, usually a suitable resin. When manufacturing large rolls, the problem arises of not knowing the degree of hardening of the matrix material. This knowledge is important, because finishing that is started too early will damage the roll frame. Other composite-construction rolls are disclosed in Finnish patent publications FI 94403 and FI 100264. In roll manufacturing, there is a great need to understand the hardening event and to control manufacture more precisely. Uncontrolled hardening shrinkage distorts the shape of the roll and causes unnecessary residual stresses, which reduce the roll's service life. Controlled manufacture and subsequent monitoring of the roll are key factors in increasing reliability. In the case of composite rolls, information is needed from other parts of the roll as well as from the surface. This is especially so, as unlike in a metal structure, a composite roll's most critical point is not necessarily on its surface. During operation, it is important to know the stresses acting in the roll, both to be able to monitor the roll's loading and for possible process control. PCT application publication WO 96/25288 discloses one system intended for monitoring nip loads, one embodiment of which uses optical fibers set into the surfacing to measure stress. Though such a sensor will certainly show the nip load, it will not show the stresses acting in the roll. SUMMARY OF THE INVENTION The present invention provides an entirely new kind of composite-construction roll and a method for manufacturing it, which will permit the manufacture of a better composite-construction roll and give advantages when using it. More specifically, a composite-construction roll includes a roll frame reinforced with reinforcing fibers, characterized in that among the reinforcing fibers there is at least one optical fibre and that the roll includes terminals arranged in this optical fibre for a transmitter and a receiver for measuring a selected optical quantity from the fibre. A method for manufacturing a composite roll, in which composite roll there is a roll frame and a possible surfacing and in which manufacturing of the roll frame the reinforcing fibers are fed simultaneously with the matrix material is characterized in that at least one optical fibre is fed among the reinforcing fibers. The use of a composite roll in a paper/board or finishing machine, in which the roll drives or only supports the fabric, is characterized in that the measurement of the stress in the roll is used to measure the tension of the fabric. Placing optical fibers among the reinforcing fibers will ensure that they become located inside the roll frame and will permit monitoring of internal events in the roll frame. Other benefits and embodiments of the invention appear in connection with the following examples. These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 shows a schematic view of a composite-construction roll together with an optical-fibre arrangement; and FIG. 2 shows the entire arrangement of optical fibers together with th e measuring terminals. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings in detail, numeral 10 generally indicates The roll frame 11 of the composite-construction roll is mainly manufactured in a known manner by winding reinforcing fibers 16 spirally on top of a suitable form and simultaneously feeding matrix material. The roll frame generally includes several fibre layers, in which the fibers are oriented differently, according to the desired properties. FIG. 1 shows schematically how the optical fibre fed along with the reinforcing fibre settles into place in the roll frame. In the figure, the optical fibre is placed so that its ends appear at the opposite ends of the roll frame 11 , so that suitable terminals can be attached to them. If necessary, optical fibers can be placed in two or several layers in the roll frame. Measurement principles that can possibly be used in connection with the optical fibre are strain measurement in a long fibre using a strain gauge operating on the transit time principle, so-called EFPI (external Fabry-Perot interferometer) sensors, or Bragg's lattice sensors. A few of both Bragg's lattice and EFPI sensors can be installed in the same fibre, when a chain of point-like ‘optical strain gauges’ will be obtained. The strain measurement device can be used to measure either changes in length taking place over the entire sensor fibre or, if there are intermediate marks in the fibre, changes in the locations of these intermediate marks. FIG. 2 shows a diagram of the fibre of FIG. 1 detached from the roll frame and connected to measurement terminals. In this case, a lattice-structure fibre is used as the optical fibre 12 , in which there are special reflector points 14 at regular intervals, which are sensitive to pressure. The transmitter and receiver 13 of the fibre are at one end and there is a mirror 15 at the other. The transceiver is connected to a telemetry instrument 17 , which sends the measurement results to a base station. This allows the fibre to be installed in a rotating roll. The measurement terminals attached at regular intervals can also be used to monitor the hardening of the matrix material during the manufacture of the roll. The measurement devices are preferably connected to the optical fibre 12 immediately after feeding the reinforcing fibers 16 and the matrix material, the equalization of the fibre being measured as a function of time, providing a basis from which to determine the degree of hardening of the matrix material and/or the aging of the roll frame 11 . It is possible to use a composite-construction roll according to the invention to measure thermodynamic state variables, such as deformation, temperature, moisture content, damage, etc. These quantities can then be used to estimate the service life and operating reliability of the roll. The tension of the fabric carried by the roll can be estimated by measuring the stresses in the roll. The deflection of the roll causes stretching in the fabric, which can be measured in a manner that is, as such, known. A roll according to the invention is eminently suitable for use in a paper/board/finishing machine, both in nip roll applications and in rolls without nips. Examples of applications include press rolls, such as the backing roll of a long-nip press, calendar rolls, coating equipment rolls, spreader an guide rolls, and rolls used in winders. In one embodiment, at least part of the reinforcing fibre of the roll frame 11 is a continuous reinforcing fibre. In one embodiment, the continuous reinforcing fibre 16 is arranged as one or several spiral layers around the roll frame 11 . In one embodiment, the orientation of the reinforcing fibre is different in adjacent layers. In one embodiment, the optical fibre is arranged to measure the tension in the roll frame 11 at at least one point in the roll. This can be further adapted to monitor or even measure the tension of the fabric driven by the roll. Although the invention has been described by reference to a specific embodiment, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiment, but that it have the full scope defined by the language of the following claims.	A composite-construction roll, includes a roll frame reinforced with reinforcing fibers, and a method for manufacturing such a roll. There is at least one optical fibre among the reinforcing fibers and the roll includes terminals arranged in this optical fibre for a transmitter and a receiver for measuring a selected optical quantity from the fibre.	6
FIELD OF THE INVENTION [0001] The present invention relates to a locking and ratcheting connector. BACKGROUND OF THE INVENTION [0002] Connectors can be susceptible to uncoupling due to vibration or other external forces. Disclosed herein is a connector that is capable of withstanding vibration or other external forces without uncoupling from another connector. SUMMARY OF THE INVENTION [0003] According to one aspect of the invention, a connector for releasably connecting with a mating connector, comprises a connector body; a first sleeve rotatably coupled to said connector body and including means for connecting with the mating connector; a second sleeve receiving said first sleeve and being movable axially between an engaged position and a disengaged position, said second sleeve having a plurality of teeth extending from a surface thereof; a ratchet ring positioned on said connector body, said ratchet ring having a plurality of teeth corresponding to said plurality of teeth of said second sleeve; and a biasing member biasing said second sleeve to said engaged position, wherein said teeth of said ratchet ring engage said teeth of said second sleeve when said second sleeve is in said engaged position such that said first and second sleeves are not rotatable with respect to said connector body in at least one rotational direction, and said teeth of second sleeve being spaced from said teeth of said ratchet ring when said second sleeve is in said disengaged position such that said first and second sleeves are rotatable with respect to said connector body and the mating connector in two rotational directions. [0004] According to another aspect of the invention, a connector comprises a connector body; a first sleeve rotatably coupled to said connector body; a second sleeve defining an interior space in which said first sleeve is positioned, said second sleeve being movable axially with respect to said connector body between an engaged position and a disengaged position, said second sleeve having a plurality of teeth extending from a surface thereof; a ratchet ring positioned on said connector body, said ratchet ring having a plurality of teeth corresponding to said plurality of teeth of said second sleeve; and a biasing member biasing said second sleeve to said engaged position, wherein said teeth of said ratchet ring engage said teeth of said second sleeve when said second sleeve is in said engaged position thereby preventing rotation of said first and second sleeves with respect to the connector body in at least one rotational direction, wherein to move said second sleeve from said engaged position to said disengaged position, in which the first and second sleeves are rotatable with respect to the connector body in two different rotational directions, said second sleeve is moved away from said ratchet ring to separate said teeth of said second sleeve from said teeth of said ratchet ring. [0005] According to yet another aspect of the invention, a connector comprises a connector body; a first sleeve rotatably coupled to said connector body; a second sleeve defining an interior space in which said first sleeve is positioned, said second sleeve being movable axially with respect to said connector body between an engaged position and a disengaged position, said second sleeve having a plurality of teeth extending from a surface thereof; a ratchet ring arranged on said connector body such that the ratchet ring is axially fixed and non-rotatable with respect to said connector body, said ratchet ring having a plurality of teeth corresponding to said plurality of teeth of said second sleeve; and a biasing member biasing said second sleeve to said engaged position, wherein said teeth of said ratchet ring engage said teeth of said second sleeve when said second sleeve is in said engaged position, and said teeth of second sleeve being spaced from said teeth of said ratchet ring when said second sleeve is in said disengaged position. BRIEF DESCRIPTION OF THE DRAWINGS [0006] The invention is best understood from the following detailed description when read in connection with the accompanying drawings, with like elements having the same reference numerals. Included in the drawings are the following figures: [0007] FIG. 1 is an elevation view taken from the left hand side of a connector according to one exemplary embodiment of the invention. [0008] FIG. 2 is a front elevation of the connector of FIG. 1 . [0009] FIG. 3 is a rear elevation of the connector of FIG. 1 . [0010] FIG. 4 is a cross-sectional view of the connector taken along the lines 4 - 4 in FIG. 3 . [0011] FIG. 5 is a cross-sectional view of the connector taken along the lines 5 - 5 in FIG. 3 . [0012] FIG. 6 is a cross-sectional view of the connector taken along the lines 6 - 6 in FIG. 5 . [0013] FIGS. 7 and 8 are exploded views of the connector of FIG. 1 taken from rear and front perspectives. [0014] FIGS. 9A and 9B are cross-sectional views, like the view in FIGS. 4 and 5 , of the connector (connector body omitted) shown in locked and unlocked configurations, respectively. [0015] FIG. 10 depicts a mating connector that is configured to mate with the connector of FIG. 1 . DETAILED DESCRIPTION OF THE INVENTION [0016] FIGS. 1-8 depict a connector 1 that is capable of withstanding vibration or other external forces without uncoupling. The connector 1 may also be referred to as an adapter or a coupler. The connector 1 is shown in FIG. 10 , for example, releasably mating to a mating connector 104 . The connector 1 may be used in various applications, such as a fluid application or an electrical application. [0017] Unless otherwise noted, each of the components of the connector 1 has a substantially cylindrical shape that is revolved about a longitudinal axis ‘A’ and each of the components has a substantially hollow interior. Also, as used herein, the term ‘distal’ refers to a position either at or toward a first end 2 a of a connector body 2 , and the term ‘proximal’ refers to a position either at or toward the second end 2 b of the connector body 2 . [0018] The connector 1 includes connector body 2 upon which the remaining components of the connector 1 are mounted either directly or indirectly. [0019] Connection means 2 c are provided on the outer surface of the first end 2 a of the connector body 2 for releasably mating with a backshell (not shown) or a strain relief (not shown), for example. According to this exemplary embodiment, the connection means 2 c are male mechanical threads. The connection means 2 c could be, for example, female mechanical threads, a bayonet connection, a clip, a clamp, a fastener, a post, a prong, a spring, a ring, a friction fit, or an adhesive. A bayonet-style connection is shown in U.S. Pat. No. 3,478,302, for example, which is incorporated by reference herein in its entirety. [0020] As best shown in FIG. 10 , the second end 2 b of the connector body 2 includes a series of axially-extending lugs 2 d that are slidably positioned within axially-extending channels 105 (one shown) of the mating connector 104 . Engagement between the lugs 2 d and the channels 105 permit axial translation, yet prevent relative rotation, between the connector body 2 and the mating connector 104 . It should be understood that the connector body 2 could include the channels and the mating connector 104 could include the lugs to achieve the same result. [0021] The interior region of the connector body 2 is hollow and the hollow space could be used to accommodate a cable (not shown) passing therethrough, for example. The cable could contain one or more wires or a passage for fluid for example. As another alternative, the hollow interior region of the connector body 2 could be used for the passage of fluid. [0022] The connector body 2 includes three axially extending channels 5 formed on its exterior surface. The channels 5 are evenly spaced apart about the circumference of the body 2 . The channels 5 interact with a ratchet ring 4 to prevent relative rotations between the body 2 and the ring 4 . The connector body 2 also includes a recess formed on its outer surface in which a retaining ring 3 is fixedly positioned. The purpose of the retaining ring 3 and the channels 5 will be described hereinafter. [0023] The ratchet ring 4 is radially positioned between the outer sleeve 8 and the connector body 2 , and is axially positioned between the inner sleeve 9 and the outer sleeve 8 . The ratchet ring 4 is positioned over the revolved exterior surface of the connector body 2 such that the ratchet ring 4 is fixedly connected to the body 2 . The ratchet ring 4 is incapable of rotation and translation with respect to the body 2 . More particularly, the ratchet ring 4 is incapable of translating upon the surface of the body 2 and along the longitudinal axis “A” because the ring 4 is sandwiched, along with an inner sleeve 9 , between the retaining ring 3 and a shoulder 2 e (see FIG. 4 ) that is formed on an exterior surface of the body 2 . [0024] As best shown in FIG. 6 , the ratchet ring 4 is incapable of rotating upon the surface of the body 2 and about the longitudinal axis “A” because the ring 4 is keyed to the body 2 . More particularly, the ratchet ring 4 includes three lugs 6 which are positioned within respective channels 5 on the body 2 . Engagement between the lugs 6 and the channels 5 prevent rotation of the ratchet ring 4 about axis “A” with respect to the connector body 2 . [0025] Each lug 6 extends in a radial direction toward the longitudinal axis “A”. The lugs 6 are evenly spaced apart about the circumference of the ratchet ring 4 . It should be understood that the number and position of the lugs 6 and the channels 5 may vary so long as the lugs 6 and channels 5 cooperate together to prevent rotation of the ratchet ring 4 with respect to the connector body 2 . Also, although not shown, it should be understood that the lugs 6 could be provided on the body 2 and the channels 5 could be provided on the ratchet ring 2 to achieve the same result. [0026] A series of ratchet teeth 12 are provided on the distal end of the ratchet ring 4 . The teeth 12 are evenly spaced about the circumference of the ratchet ring 4 . Each ratchet tooth 12 is formed in the shape of a right triangle having a straight edge and a sloped edge. The ratchet teeth 12 engage mating ratchet teeth 13 on an outer sleeve 8 , as will be described with respect to the outer sleeve 8 . [0027] An inner sleeve 9 is mounted to the outer surface of the connector body 2 such that it is capable of rotating freely on the surface of the connector body 2 . The inner sleeve 9 is radially positioned between the outer sleeve 8 and the connector body 2 , and is axially positioned between the ratchet ring 4 and the shoulder 2 e of the connector body 2 . The inner sleeve 9 is incapable of translating along the longitudinal axis “A,” with respect to the connector body 2 (or any other component of the coupling 1 ). The inner sleeve 9 is incapable of translation because it is sandwiched, along with the ratchet ring 4 , between the retaining ring 3 and the shoulder 2 e (see FIG. 4 ) that is formed on the exterior surface of the body 2 . [0028] Connection means 17 are provided on the inner revolved surface of the inner sleeve 9 for releasably mating with the connection means 106 of the mating connector 104 (see FIG. 10 ). Upon mating the mating connector 104 with the connector 1 , the mating connector 104 is at least partially positioned within the annular space 19 (see FIG. 4 ) that is defined between the body 2 and the inner sleeve 9 . According to this exemplary embodiment, the connection means 17 and 106 are mechanical threads. The connection means could be, for example, a bayonet connection, a clip, a clamp, a fastener, a post, a prong, a spring, a ring, a friction fit, or an adhesive. [0029] As best shown in FIGS. 5-8 , the outer surface of the inner sleeve 9 includes an outwardly extending shoulder 9 a and three outwardly extending lugs 14 . Each lug 14 extends from the shoulder 9 a in an axial direction toward the distal end of the inner sleeve 9 . The lugs 14 are evenly spaced apart about the circumference of the inner sleeve 9 . The inner sleeve 9 interacts with an outer sleeve 8 , as will be described hereinafter. [0030] The outer sleeve 8 is positioned over the circumference of the inner sleeve 9 such that the outer sleeve 8 is slidably, but non-rotatably, connected to the inner sleeve 9 . The outer surface of the outer sleeve 8 includes serrations 8 a and cutouts 8 b formed therein to enhance manual gripping of the outer sleeve 8 by a user of the coupling connector 1 . The outer surface of the outer sleeve 8 may also be referred to herein as a gripping surface. [0031] The outer sleeve 8 includes three axially extending channels 15 formed on its interior surface. The channels 15 are evenly spaced apart about the inner circumference of the outer sleeve 8 . Each channel 15 is sized to receive a lug 14 of the inner sleeve 9 . The keyed engagement between the lugs 14 and the channels 15 permits sliding of the outer sleeve 8 over the inner sleeve 9 in an axial direction (i.e., along axis “A”), while preventing rotation of the outer sleeve 8 with respect to the inner sleeve 9 (i.e., about axis “A”). Thus, the inner sleeve 9 and the outer sleeve 8 rotate together with respect to the ratchet ring 4 and the body 2 , which are rotationally fixed with respect to the sleeves 8 and 9 . [0032] It should be understood that the number and position of the lugs 14 and the channels 15 may vary so long as the lugs 14 and the channels 15 cooperate together to permit sliding of the outer sleeve 8 over the inner sleeve 9 , yet prevent rotation of the outer sleeve 8 with respect to the inner sleeve 9 . Stated differently, the inner sleeve 9 and the outer sleeve 8 must rotate together. Also, although not shown, it should be understood that the lugs 14 could be provided on the outer sleeve 8 and the channels 15 could be provided on the inner sleeve 9 to achieve the same result. [0033] A series of teeth 13 are formed on an interior facing surface on the distal end of the outer sleeve 8 . The teeth 13 are evenly spaced about the circumference of the outer sleeve 8 . Like the teeth 12 of the ratchet ring 4 , each ratchet tooth 13 is formed in the shape of a right triangle having a straight edge and a sloped edge. [0034] As shown in FIGS. 4 and 5 , the proximal end 8 c of the outer sleeve 8 curves inwardly toward the longitudinal axis to encapsulate a spring retainer 7 . The spring retainer 7 is a cylindrical sleeve that is provided to captivate a spring 10 within the connector 1 . Like the outer sleeve 8 , the proximal end 7 a of the spring retainer 7 is rolled inwardly toward the longitudinal axis to encapsulate the spring 10 . The spring retainer 7 is slidably positioned between the inner sleeve 9 and the outer sleeve 8 . The proximal end 7 a of the spring retainer 7 can slide along the surface of the inner sleeve 9 . The spring retainer 7 may or may not be rotationally keyed to the sleeves 8 and 9 . The revolved interior surface of the spring retainer 7 rests on the outer surface of the inner sleeve 9 such that the spring 10 may not be disassembled from the connector 1 . It should be understood that the spring retainer 7 may be integrated with the proximal end 8 c of the outer sleeve 8 to achieve the same purpose. [0035] As best shown in FIG. 4 , the spring 10 is a resilient compression spring that is sandwiched between the proximal end 7 a of the spring retainer 7 and the shoulder 9 a of the inner sleeve 9 . The spring 10 is configured to bias the teeth 13 of the outer sleeve 8 against the teeth 12 of the ratchet ring 4 . Simply stated, the spring 10 is configured to urge the outer sleeve 8 to a locked position in which the teeth 12 and 13 are engaged with each other. [0036] Stated differently, the spring 10 urges the outer sleeve 8 in a proximal direction (by way of the spring retainer 7 ), while it also urges the shoulder 9 a of the inner sleeve 9 in a distal direction. The shoulder 9 a of the inner sleeve 9 consequently urges the ratchet ring 4 in a distal direction against the interior surface of the proximal end 8 d of the outer sleeve 8 . Thus, the teeth 12 of the ratchet ring 4 are biased against the teeth 13 of the outer sleeve 8 . [0037] FIG. 10 depicts the connector 1 aligned and ready for mating with the mating connector 104 . The mating connector 104 includes a cylindrical body having connection means 106 on one end of the connector 104 for mating with the connection means 17 on the inner sleeve 9 , as previously described, and another connection means 108 on an opposite end of the connector 104 for mating with a backshell (not shown) or a strain relief (not shown), for example. [0038] Axially extending channels 105 (one shown) are disposed on the interior surface of the end of the mating connector 104 for slidably receiving lugs 2 d on the connector body 2 . Engagement between the lugs 2 d and the channels 105 permits relative translation, while preventing relative rotation, between the connector body 2 and the mating connector 104 . [0039] It should be understood that since the inner sleeve 9 is capable of rotation with respect to the connector body 2 , the inner sleeve 9 is also capable of rotation with respect to the mating connector 104 . More particularly, the inner sleeve 9 can be rotated onto the connection means 106 of the mating connector 104 (or vice versa) in a tightening direction without manually moving the outer sleeve 8 , however, the inner sleeve 9 cannot be rotated onto the connection means 106 of the mating connector 104 (or vice versa) in a loosening direction without manually moving the outer sleeve 8 in the direction shown in FIG. 9B . In other words, once the connector 1 is mated to the mating connector 104 , a user must first pull the outer sleeve 8 in the direction shown in FIG. 9B , and then rotate the outer sleeve 8 in a loosening direction to uncouple the connector 1 from the mating connector 104 . [0040] Referring now to the operation of the connector 1 , the connector 1 is connected to the mating connector 104 by performing the following steps: (a) manually aligning the lugs 2 d of the body 2 within respective channels 105 of the mating connector 104 ; (b) manually engaging the connection means 17 of the inner sleeve 9 with the connection means 106 of the mating connector 104 ; and (c) manually rotating the outer sleeve 8 (which in turn rotates the inner sleeve 9 ) in a tightening direction, consequently engaging the connection means 17 of the inner sleeve 9 with the connection means 106 of the mating connector 104 . [0041] During rotation step (c), the mating connector 104 translates in an axial direction toward the connector body 2 (or vice versa) without rotating by virtue of the keyed engaged between the lugs 2 d and the channels 105 . During rotation step (c), the teeth 13 of the outer sleeve 8 are engaged with the teeth 12 of the ratchet ring 4 by virtue of the biasing spring 10 . Rotating the outer sleeve 8 in the tightening direction causes the sloped surfaces of the teeth 12 and 13 to slide past each other, thereby permitting rotation of the outer sleeve 8 with respect to the connector body 2 and the mating connector 104 (i.e., assuming that the mating connector 104 is fixed in place and prevented from rotation). As the teeth 12 and 13 slide past each other, the outer sleeve 8 moves slightly forwards and backwards in an axial direction. Rotation of the outer sleeve 8 in the tightening direction is possible until the connection means 17 of the connector 1 is fully engaged with the connection means 106 of the mating connector 104 . [0042] The connector 1 is then maintained in the locked configuration, and it cannot be detached from the mating connector 104 without manual intervention by an end user. In the locked configuration, the sleeves 8 and 9 are prevented from inadvertently rotating in a loosening rotational direction with respect to the connector body 2 and the mating connector 104 due to vibration or other external forces. Attempting to rotate the outer sleeve 8 in the loosening rotational direction while the outer sleeve 8 is maintained in the locked configuration, either purposefully or inadvertently, causes the flat surfaces of the teeth 12 and 13 to bear on each other by virtue of the spring 10 , thereby preventing rotation of the outer sleeve 8 and the inner sleeve 9 in the loosening direction with respect to the connector body 2 and the mating connector 104 . Thus, the connector body 2 and the mating connector 104 are each prevented from rotating in the loosening rotational direction with respect to the inner sleeve 9 , or vice versa, thereby preventing detachment of the mating connector 104 from the connector 1 . [0043] To detach the mating connector 104 from the connector 1 , it is necessary to first move the outer sleeve 8 from the locked configuration of FIG. 9A to the unlocked configuration of FIG. 9B by pulling the outer sleeve 8 in the distal direction (see arrows in FIG. 9B ) against the force of spring 10 . This causes the teeth 13 of the outer sleeve 8 to separate from the teeth 12 of the ratchet ring 4 . Once the teeth 12 and 13 are separated, the outer sleeve 8 is rotated in the loosening direction. Rotating the outer sleeve 8 in the loosening direction causes the inner sleeve 9 to rotate with respect to the connector body 2 and the mating connector 104 , thereby causing the connection means 17 of the inner sleeve 9 to separate and detach from the connection means 106 of the mating connector 104 . As the outer sleeve 8 and the inner sleeve 9 are rotated in the loosening direction, the mating connector 104 and the connector body 2 translate away from each other, and without relative rotation, by virtue of the keyed engaged between the lugs 2 d and the channels 105 . [0044] Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.	A connector includes a connector body; a first sleeve rotatably coupled to the connector body; a second sleeve receiving the first sleeve and being movable axially between an engaged position and a disengaged position, the second sleeve having a plurality of teeth extending from a surface thereof; a ratchet ring positioned on the connector body, the ratchet ring having a plurality of teeth corresponding to the plurality of teeth of the second sleeve; and a biasing member biasing the second sleeve to the engaged position, wherein the teeth of the ratchet ring engage the teeth of the second sleeve when the second sleeve is in the engaged position, and the teeth of second sleeve being spaced from the teeth of the ratchet ring when the second sleeve is in the disengaged position.	8
FIELD OF THE INVENTION The invention relates to grab bars, and more particularly to a portable grab bar that may be carried by a person requiring the use of such a device and applied to a surface to provide the sole grab bar where none is provided, or which may supplement a permanently installed grab bar by being more conveniently located for the user. BACKGROUND OF THE INVENTION The provision of grab bars is becoming more widespread in lodging accomodations, especially in bathroom environments, to assist and aid people with disabilities in using the bathroom facilities. Thus, bath tubs and showers may be provided with permanently mounted grab bars that enable a person to steady himself when getting into or out of the tub or shower or, when mounted adjacent toilet facilities, to provide a support which the person can use to pull himself to a standing position. While their presence is increasing, the provision of grab bars is by no means universal, and disabled or handicapped people often encounter facilities where there are no permanently mounted grab bars. The absence of grab bars increases the hazard to a handicapped or disabled person in using the facility when a grab bar would be a great convenience or safety feature for that person. GENERAL DESCRIPTION OF THE INVENTION It is the object of the invention to provide a portable grab bar for use by a handicapped or disabled person. It is another object of the invention to provide a grab bar that can be carried by a person when traveling and applied to a surface when needed. It is still another object of the invention to provide a grab bar that can readily be mounted and dismounted from a surface. It is yet another object of the invention to provide a portable grab bar that is adjustable in length. In carrying out the invention, there is provided a grab bar having at each end thereof a suction device by which the bar may be attached to a flat, non-porous surface. The bar itself may be a telescoping unit so that its length may be short enough to be carried in an attache case or other piece of luggage and yet extensible to a length suitable for its use. Features and advantages of the invention may be gained from the foregoing, and from the description of a preferred embodiment thereof which follows. DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view showing the grab bar of the invention mounted in a shower stall; FIG. 2 is a front elevational view, partly in section, showing the grab bar of the invention; FIG. 3 is a top plan view of the grab bar shown in FIG. 2; and FIG. 4 is a side elevational view of a suction device which secures the grab bar to a surface. DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 grab bar 10 is shown mounted in a shower stall. Of course, bar 10 could be mounted in a bathroom or any other room or place where a person desires the support or assistance provided by a grab bar. The bar may be mounted horizontally, diagonally, or with any orientation convenient to the user. Reference is now made to FIGS. 2 and 3 for a detailed description of grab bar 10. The bar is seen to comprise an inner stainless steel tube 11 that slides within outer tube 12, also formed of stainless steel. Outer tube 12 is secured within end post 13 which itself is threaded onto stud 14 of the suction device 15. This device will be further described hereinafter when FIG. 4 is considered. As shown in the sectional portion of FIG. 2, the end of tube 12, which is fitted into the bore 16 formed in post 13, is provided with a pair of opposed apertures 17. In assembling grab bar 10, these apertures 17 are aligned with the threaded screwhole 20 which extends axially through end post 13. A set screw 21 is threaded into screwhole 20 and through both apertures 17, thereby securing tube 12 in end post 13. A second set screw 22 is threaded into screwhole 20 flush with the top surface of post 13. Inner tube 11 is similarly secured in the other end post 19. The free end of tube 12 (that is, the end remote from post 13) is threaded, as at 23, so that a knurled lock nut 24 can be threaded thereon. Nut 24 slides freely on inner tube 11, and as previously noted tube 11 slides freely within outer tube 12, but when nut 24 is threaded onto tube 12 it jams the grommet 25 against the end of the tube 12 and locks inner tube 11 and tube 12 in the relative position they are in when nut 24 is tightened. In this way, the length of grab bar 10 can be freely adjusted to substantially the combined lengths of tubes 11 and 12. In addition to the length adjusting arrangement just described, tube 12 may be provided with a series of spaced apart linearly aligned apertures 26 which serve as detents for pawl 27 carried by inner tube 11. The pawl is biased into a locking position in engagement with one of apertures 26 by a spring 30. It will be noted that when pawl projects through an aperture 26, the sidewall of the pawl is perpendicular to the axis of tube 12 and therefore inner tube 11 cannot slide within tube 12. However, when pawl 27 is depressed, as by finger pressure applied thereto, the rounded tip of pawl 27 engages aperture 26 and tubes 11 and 12 can be moved relative to one another until pawl 27 is spring biased and fully extended through another aperture 26. Either or both of the described arrangements for locking grab bar 10 in an adjusted length may be used. The suction device 15 (FIG. 4) which is preferred for use in grab bar 10 is marketed by Wood's Power Grip Co., Inc. of Wolf Point, Mont., and comprises a suction cup 31, a vacuum pump 32, mounting plate 33, and threaded stud 34. The device shown in the drawing is Model TL3-AM vacuum grip with accessory mount. The suction device may be used on any relatively smooth, non-porous surface that does not provide an air passageway under the edge of suction cup 31. In use, the length of grab bar is adjusted so that the suction cup of each suction device 15 may be placed on a smooth, non-porous surface. Thus, if the grab bar is to be used in a tiled bathroom, its length is adjusted so that each suction cup is placed on an individual tile and does not overlay any grout joint. The suction cup is then pressed against the tile and spring biased plunger 35 of pump 32 repeatedly depressed until the suction indicating mark 36 on plunger remains below the top edge of the pump barrel. If the suction cup begins to leak air so that plunger 35 is spring biased out of the pump barrel and mark 36 becomes visible, adequate suction can be restored by again repeatedly depressing plunger 35. When it is desired to remove grab bar from the surface to which it is mounted, an edge of the suction cup 31 can be raised with a finger to allow air to leak under the edge of the cup, thus destroying the vacuum holding the cup to the surface. A tab 37 may be provided on the outer surface of cup 31 to facilitate lifting of the edge of the cup when it is desired to remove the grab bar 10 from a surface. After removal of the grab bar from a surface, the bar will generally be adjusted to its most compact length so that it may be conveniently stored, or packed in the luggage of a traveller. As mentioned earlier, the disclosed grab bar is especially suited to the needs of disabled persons who travel and often encounter travel accommodations that do not have grab bars where they may be required by the disabled person. Having thus described the invention, it is to be understood that many apparently different embodiments may be made without departing from the spirit and scope of the invention. For example, each suction device 15 may include more than one suction cup so that the grab bar may be used on a tiled surface using smaller tiles. In such a case, a large suction cup would span a grout joint which would prevent the suction cup adhering to the surface. Smaller suction cups would each individually cover a tile but would not span any grout joint. More than one suction cup would be required to provide the adhering force necessary to adequately support a person using the grab bar. Therefore, it is intended that the foregoing description and the accompanying drawing be interpreted as illustrative and not in a limiting sense.	A portable grab bar that has suction members at each end thereof to permit attachment of the bar to a flat non-porous surface.	0
CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation-in-part of application Ser. No. 599,436, filed July 28, 1975 now abandon. FIELD OF THE INVENTION The present invention relates to a flat knitting machine having four opposed needle beds, comprising front and back main beds and front and back auxiliary beds located above the main beds. DESCRIPTION OF THE PRIOR ART A flat knitting machine of the type mentioned has already been described in French Pat. No. 1,073,501. Suitably equipped flat knitting machines having at least two opposed needle beds are capable of producing, in the form of a flat fabric, every known kind of knitting texture producible on flat machines. The flat portions of fabric knitted on such a machine must be later joined and linked together in a fairly laborious additional operation for the purpose of producing a finished article of knitwear. SUMMARY OF THE INVENTION It is an object of the present invention to provide a flat knitting machine which will permit every known type of knitting texture to be produced not only in the form of flat fabrics but also in the form of tubularly knitted fabrics, in other words knitted fabrics with double-sided or single-sided designs to be produced in the form of tubular knitting. According to the invention this is accomplished in a flat knitting machine having two or more opposed knitting beds, in which each main bed and the auxiliary bed which faces it form a pair of co-operating needle beds in a flat Vee-bed knitting machine, and in which a cam assembly is provided on a carriage adapted to traverse the length of the needle beds for imparting knitting and loop transferring motions to the needles in the main beds as well as in the auxiliary beds. The knitting of known kinds of knitting textures in the form of tubular fabric on the proposed flat knitting machine has the advantage that the work in the make-up department in the production of knitwear, such as the production of fancy stitch pullovers, is greatly reduced. Since in the case of a pullover the sleeves as well as the front and back portions of the body can be produced in the form of a fully fashioned tubular fabric, the completion of such a garmet merely calls for the joining together of these parts i.e. three in the case of a pullover. The cam assembly preferably comprises two transfer cams, each operating in both directions of traverse, namely operating as a leading and a trailing transfer cam, respectively, and a double stitch cam system interposed between them. A preferred embodiment of the invention is represented in the accompanying drawings and will be more particularly described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a flat knitting machine according to the invention, showing the needle beds and the carriage; FIG. 2 is a side elevational view of part of the needle beds and of the cam system used in FIG. 1, the view being from the right in FIG. 1; FIGS. 3 to 3h are diagrammatic representations of the method of operation for the production of a tubular rib knit fabric; FIGS. 4 to 4l are diagrammatic representations of the method of operation for the production of a purl knit tubular fabric, FIGS. 5 to 5z; 5a' to 5z'; 5a" and 5b" are diagrammatic representations of the method of operation for the production of a fancy design in a tubular fabric. FIG. 6 is an elevational view of all needle beds and of the cam system with certain cam parts being in action, FIG. 7 is a view similar to the view of FIG. 6 with other cam parts being in action, and FIG. 8 is a side and elevational view of the means for moving the needle beds. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 there is provided a flat knitting machine, of the kind also described as a twin Vee-bed flat kniting machine, which has needle beds disposed as shown in the drawings. The needle beds comprise a front main bed (F.M.B) 1, a back main bed (B.M.B) 2, a front auxiliary bed (F.A.B) 3 and a back auxiliary bed (B.A.B) 4. The several beds contain needles 11, 12, 13 and 14 respectively. The needle beds are movable on appropriately designed needle bed carriers. In the particular embodiment illustrated in FIG. 1 the main beds 1 and 2 are disposed at an acute angle forming a Vee. The front auxiliary bed 3 is disposed above the back main bed 2 and the back auxiliary bed 4 is above the front main bed 1, each auxiliary bed being downwardly inclined towards the inside. The front main bed 1 and the front auxiliary bed 3 as well as the back main bed 2 and the back auxiliary bed 4 are likewise relatively inclined at an acute angle forming a Vee. A carriage 5 is adapted to traverse the length of the needle beds and contains an assembly of cams comprising a leading and trailing transfer cam working in both directions of carriage traverse and a double-stitch cam system located thereinbetween. Yarn guides 6 are provided above the needle beds. FIG. 2 illustrates part of the cam assembly on the carriage 5, namely that above the main bed 1. The construction of the other parts of the cam assembly associated with the main bed 2 and the auxiliary beds 3 and 4 is analogous to that of the cams shown in FIG. 2 for cooperation with the main bed 1. The flat knitting machine of the invention may be regarded for purposes of description as being a combination of two ordinary flat machines. The four needle beds are so disposed that every conventional type of knitting texture producible on a flat knitting machine can be knitted in the form of a tubular fabric. The carriage 5, as shown in FIG. 1, is the carrier of locks 39, 40, 41, 42 and of thread guide drivers 43. It consists of carriage jaws 44, 45, 46 and 47 as well as carriers 48 and 49 for carriage jaws and of a high stirrup 50. Its ball and friction bearings 51, 52, 53, 54, 55 and 56 are disposed such that the carriage is capable of sliding back and forth on carriage guide rails 57, 58. It obtains movement from a chain drive 59. The chain drive consists of a motor 60 with a V-belt 61, a driving rocker arm (crank) 62, a crank guide bar 63 and a connecting lever 64 which couples the carriage with the drive. On the outside the needle beds 1, 2, 3 and 4 have left and right screw-on surfaces which serve for the reception of two bearings and of the racking bar. The needle beds are screwed to the base body of the machine, the needle bed 1 to a tube (pipe) profile 65, the needle bed 2 to a tube profile 66, the needle bed 3 to a tube profile 67 and the needle bed 4 to a tube profile 68. The attachment or mounting as well as the moving mechanism of the needle bed 3 which, just like also the needle bed 4 is laterally shiftable and in the direction of movement of the needles, is shown in FIG. 8. To the left and the right outside, there is always one bearing 69 attached on the reverse side of the needle bed in which always a guide bolt 70 is attached. This bolt projects into the elongated hole of a lever 71 and transmits the inforced eccenter motion of an eccentric 72 into an up and down movement of the needle bed. For the purpose of the lateral movement of the needle bed, there likewise are, left and right on the outside and on the reverse side of the needle bed, guide pieces 73 which are connected by way of rollers 74 with a shifting curve 75. The eccentric 76 moves the latches 77 up and down. The shifting curve 75 moves backward and forward depending on the position of the latch and thus it moves the needle bed to the left and to the right. For the purpose of knitting a single bed tubular fabric it is best to arrange for cooperation of the front and back main beds 1 and 2, whereas for knitting single or double bed transfer stitch patterns by tubular knitting the main beds 1, 2 and the auxiliary beds 3, 4 can be made to cooperate. Moreover, for knitting rack rib designs the front auxiliary bed 3 can be used for racking the loops at the front and the back auxiliary bed 4 for racking the loops at the back. When knitting a tubular fabric on the proposed flat knitting machine the diameter of the tube is advantageously variable by changing the working width by the activation or inactivation of the outermost needles 11, 12, 13, 14. In conjunction with electronically controlled widening and narrowing devices a fashioned tubular knitting can thus be readily produced. The flat knitting machine of the invention also readily permits for instance tubular rib or tubular purl fabric to be produced. Likewise in conjunction with a, for instance, electronic needle selecting device and Jacquard, colour, Jacquard transfer stitch and Jacquard purl fabric designs can be produced in the form of tubular fabric. It is also readily possible to change the pattern whilst knitting proceeds. For instance a knitting may be started in the form of a tubular 1 × 1 rib and then continued in the form of a tubular racked rib. As already mentioned the diameter of the tubular knitting is easily changed to the desired size by varying the working width on the machine. The performance of the flat knitting machine is equal to that of a conventional flat knitting machine with a double cam system. The flat knitting machine of the invention also readily permits welts and parting courses to be knitted. The welts are the firm starting courses of a specific length of fabric, which cannot unrove, whereas the parting courses serve to separate two portions of fabric. If a parting course is provided between two lengths of fabric then each parting course must be followed by a welt. In the case of hand machines it is the invariable practice to insert a drawing off comb in the loops of the welt to keep the knitted fabric under downward tension. In fully automatic machines an existing fabric is run-on the needles and the bottom end of this fabric is attached to an automatic drawing off bar. The knitting of a number of illustrative examples will be hereunder more particularly described. The process of knitting a rib knit tubular fabric will first be described with reference to FIG. 3. A fabric each has been run on the front main bed 1 and on the back main bed 2 as shown in FIG. 3a. Each of the needles 11 and 12 therefore carries a loop. The carriage 5 is assumed to be at the right hand end, the back auxiliary needle bed 4 being withdrawn as in FIG. 1. The carriage 5 with the locks 39, 40, 41 and 42 is now moved to the left. At the same time, the loops of the 1st, 3rd, 5th . . . needle 11 of the forward basic bed 1 are leadingly tranferred to the 1st, 3rd, 5th . . . needle 13 of the forward auxiliary bed 3, as shown in FIG. 3b. In FIG. 6, the cam parts are stressed particularly which are operative in the process described here. First of all, the transmitting part 15 as well as the takeover part 16 are operative. After that, there follow two knitting rows as shown in FIG. 3c. For this, the knitting cams 17, 18, 19, 20 as well as 21, 22, and 23, 24 are to be made operative. Then the loops are transferred from the needle 13 of the forward auxiliary bed 3 to the empty needles 11 of the forward base bed 1, as shown in FIG. 3d. For this purpose, the transmitting part 25 and the takeover part 26 are needed. Now the carriage 5 stands on the left. The front auxiliary bed 3 is pulled back and the rear auxiliary bed 4 is moved into its base position. Now the carriage 5 is moved from left to right. In FIG. 7, the cam parts which, in this case, are operative (active), are stressed particularly. At the same time, the loops of the 2nd, 4th, 6th . . . needle 12 of the rearward basic bed 2 are leadingly transmitted to the 2nd, 4th, 6th . . . needle 14 of the rearward auxiliary bed 4, as shown in FIG. 3e. In order to achieve this, the transmitting part 27 and the takeover part 28 must be activated. Now, as indicated in FIG. 3f, two knitting rows are knit. The knitting cams 29, 30 and 31, 32 as well as 33, 34 and 35, 36 are operative. For this purpose, the loops are transmitted trailingly from the needles 14 of the rearward auxiliary bed 4 to the needles 12 of the rearward basic bed 2, which is indicated in FIG. 3g and which is achieved by means of the transmitting part 37 and the takeover part 38. FIG. 3h shows the state in which a complete carriage row is completed, that is to say two R/R(knit) rounds of hose are knit. The cam switchings take place in a known manner through bolt control (Riegelsteuerung) always in the case of the preceding reversal of the carriage. Referring to FIG. 4 the method of operation will now be described for the knitting of a tubular purl fabric. In FIG. 4a a fabric has been run on the front main bed 1 and on the back main bed 2. Each needle 11 and 12 carries a loop. Let it be assumed that the carriage 5 is at the right hand end. The back auxiliary bed 4 is withdrawn, as in FIG. 1. The carriage 5 is now first traversed to the left. As shown in FIG. 4b this causes the loops 11 on the front main bed 1 to be transferred by the leading cam to the needles 13 of the front auxiliary bed 3. Then, as shown in FIG. 4c, a course of stitches is knitted using the leading or trailing stitch cam on the carriage 5 and the loops on the needles 13 of the front auxiliary bed 3 are retransferred to the needles 11 on the front main bed 1, as shown in FIG. 4d. The carriage 5 is now on the left. The front auxiliary bed 3 is withdrawn and the back auxiliary bed 4 is brought forward into operative position. The carriage 5 is then traversed from left to right. The loops are thus now transferred by the leading cam from the needles 12 of the back main bed 2 to the needles 14 of the back auxiliary bed 4, as indicated in FIG. 4e. According to FIG. 4f another course of stitches is knitted with the leading or trailing stitch cam on the carriage 5. The loops are then re-transferred from the needles 14 of the back auxiliary bed 4 to the needles 12 of the back main bed 2, as will be understood from FIG. 4g. The carriage is now on the right and a complete circular course has been knitted, the purl loops, as shown in FIG. 4h, being visible on the outside. To prepare for the next traverse of the carriage the back auxiliary bed 4 is now withdrawn and the front auxiliary bed 3 moved into operative position. The carriage then moves from right to left and knits a course on the front main bed 1 using the leading or trailing stitch cam on the carriage 5 as shown in FIG. 4i. The carriage 5 thus changes over to the left. The next stop is the withdrawal of the front auxiliary bed 3, whereas the back auxiliary bed is brought forward, the carriage 5 then moving back to the right. As shown in FIG. 4k the leading and trailing stitch cam knits a course on the back main bed 2. The carriage 5 is therefore again on the right and the second circular course has been completed, rib loops being visible on the outside, as in FIG. 4l. The continuous change-over between plain and purl knitted courses results in the production of a tubular purl fabric. FIG. 5 exemplifies the procedure when knitting a tubular rack rib design. Before knitting begins, a tubular 1 × 1 rib knit welt has been produced, as already described with reference to FIG. 3. Purl and plain stitch loops hang on the needles 11 and 12 of the front main bed 1 and the back main bed 2 respectively, as indicated in FIG. 5a as well as in 3h. The carriage is on the right, the back auxiliary bed 4, as illustrated in FIG. 1 is withdrawn. The first step is the traverse of the carriage 5 to the left. The loops of selected needles 11 of the front main bed 1, as shown in FIG. 5b, are transferred by the leading transfer cam to the needles 13 of the front auxiliary bed. The leading and the trailing stitch cams on the carriage 5 each knit a course as indicated in FIG. 5c and the trailing transfer cam transfers the loops on the front auxiliary bed 3 to the empty needles 11 of the front main bed 1, as indicated in FIG. 5d. The carriage 5 is now on the left, the front auxiliary bed 3 is withdrawn and the back auxiliary bed 4 is brought into operative position. The carriage 5 is then moved left to right, the leading cam transferring the selected loops from the back main bed 2 to the needles 14 of the back auxiliary bed 4, as indicated in FIG. 5e. The leading and the trailing stitch cams on the carriage 5 knit 2 courses, as in FIG. 5f, whereas the trailing transfer cam, as shown in FIG. 5g transfers the loops from the back auxiliary bed 4 to the needles 12 of the back main bed 2. This carriage cycle is repeated three times, as illustrated in FIGS. 5h to 5z. The carriage is now on the right, the back auxiliary bed 4 is withdrawn and the front auxiliary bed 3 is brought into operative position. The carriage moves to the left. The loops of the selected needles 11, as shown in FIG. 5a, are transferred by the leading cam from the front main bed 1 to the front auxiliary bed 3. FIGS. 5b' and 5c' show the run of the yarn for the leading and the trailing stitch cam operating selected stitch cam needles. Moreover, the loops on the front auxiliary bed 3 are re-transferred by the trailing transfer cam to the empty needles 11 of the front main bed 1, as shown in FIG. 5d'. The carriage is now again on the left, the front auxiliary bed 3 is withdrawn and the back auxiliary bed 4 advanced into working position. The carriage 5 then traverses from left to right, and as shown in FIG. 5e' the loops on the selected needles 12 of the back main bed 2 are transferred to the needles 14 of the back auxiliary bed 4. According to FIG. 5f' a course of stitches is then knitted with the leading stitch cam and as shown in FIG. 5g' another course is knitted with the trailing stitch cam. When this has been done the loops on the back auxiliary bed 4 are transferred by the trailing transfer cam to the empty needles 12 of the back main 2 as shown in FIG. 5h'. The carriage is now again on the right, the back auxiliary bed 4 is withdrawn and the front auxiliary bed 3 is brought forward into operating position. The carriage then returns to the left. As illustrated in FIG. 5i' the loops on the selected needles 11 of the front main bed are thus transferred by the leading cam to the needles 13 of the front auxiliary bed 3. At the same time, as indicated in FIG. 5k', two courses are knitted and the trailing transfer cam causes the loops on the front auxiliary bed 3 to be transferred to the needles 11 of the front main bed 1, cf. FIG. 5l'. The carriage 5 is now again on the left. During the reversal of the carriage the front auxiliary bed 3 is racked three needle spaces to the left. The front auxiliary bed 3 is then withdrawn and the back auxiliary bed 4 is brought forward, the carriage 5 starting its traverse to the right. The leading transfer cam causes the loops on the selected needles 12 of the back main bed 2 to be transferred to the needles 14 of the back auxiliary bed 4, as indicated in FIG. 5m'. Moreover, as illustrated in FIG. 5n' the leading and the trailing stitch cams knit two courses and the loops on the back auxiliary bed 4 are re-transferred as shown in FIG. 5o', to the needles 12 of the back main bed 2. The carriage is again on the right and the back auxiliary bed 4 is racked three needle spaces to the right as the carriage reverses. The back auxiliary bed 4 is withdrawn and the front auxiliary bed 3 is brought forward into working position. The carriage 5 then moves to the left. Either the leading or trailing transfer cam causes the loops on the selected needles 11 of the front main bed 1 to be transferred to the needles 13 of the front auxiliary bed 3, as shown in FIG. 5p'. The carriage 5 is again on the left and the front auxiliary bed 3, as indicated in FIG. 5q', is racked six needle spaces to the right during the reversal of the carriage at this end. The carriage returns to the right and again selected loops are transferred from the front main bed 1 to needles 13 of the front auxiliary bed 3 by the leading or trailing transfer cam, as shown in FIG. 5r'. The carriage is once more on the right and, during its motion reversal, the front auxiliary bed 3, as indicated in FIG. 5s', is racked three needle spaces to the left. During the following traverse of the carriage 5 to the left the leading or trailing stitch cam knits two courses according to FIG. 5t' and the loops of the front auxiliary bed 3, as shown in FIG. 5u', are transferred to the empty needles 11 of the front main bed 1. The carriage 5 thus returns to the left. During carriage reversal the front auxiliary bed 3 is withdrawn and the back auxiliary bed 4 is returned into operating position. The carriage 5 returns to the left. As indicated in FIG. 5v', the selected loops on the back main bed 2 are transferred by the leading or trailing transfer cam to needles 14 of the back auxiliary bed 4. The carriage 5 is again on the right and the back auxiliary bed 4, as shown in FIG. 5w', is racked six needle spaces to the left. The carriage 5 returns to the left and the leading or trailing transfer cam again transfers selected loops from the back main bed 2 to needles 14 of the back auxiliary bed 4, as indicated in FIG. 5x'. The carriage thus again arrives at the left hand end and during motion reversal the back auxiliary bed 4 is racked three needle spaces to the right, as indicated in FIG. 5y'. As the carriage 5 now again traverses to the right the leading and the trailing stitch cams, as indicated in FIG. 5z', knit two courses and according to FIG. 5a" the loops on the back auxiliary bed 5 are transferred by the trailing transfer cam to needles 12 of the back main bed 2. FIG. 5b" finally shows the run of the yarn after a rack rib pattern repeat has been knitted at front and back. After completion the tubular knitting must be turned inside out to bring the rack rib design to the outside where it can be seen.	A flat knitting machine based on a flat Vee-bed arrangement has four opposed needle beds comprising front and back main needle beds and front and back auxiliary needle beds located above the main beds. A carriage traversible the length of the beds includes a cam assembly for imparting knitting and loop transferring motions to the needles in all the beds. By selective co-operation of the several beds flat and tubular knitted fabrics of any known design can be produced.	3
BACKGROUND OF THE INVENTION [0001] The application claims priority to German Application No. 10 2004 039 851.8, which was filed on Aug. 17, 2004. [0002] The invention relates to a window lifter rail comprising a pulley and a pulley cover. [0003] Window lifter rails with pulleys are used in cable pull type window lifters that lift and lower vehicle window panes. One known cable pull type window lifter includes a tensile member that is wound around a cable drum and several pulleys. In this arrangement, the pulleys are arranged on a window lifter rail, and the tensile member is connected to a driving dog. When the cable drum rotates, the driving dog is lifted and lowered and the window pane is moved to a desired position. [0004] Traditionally, window lifter rails include a rigid abutment that deflects the tensile member at an angle in a region of the pulleys. Different angles require different rigid abutments, such that each complete assembly unit for a respective operating condition has a unique rigid abutment. This results in significantly increased costs, because a required deflection angle of the tensile member for force transmission varies according to vehicle type, and can vary within one vehicle type depending on window type. [0005] It is the objective of the invention to provide an assembly unit for application in window lifters that offers a more flexible use in order to reduce the amount of work involved during production and to reduce costs. SUMMARY OF THE INVENTION [0006] The subject invention provides a window lifter rail with a pulley and a pulley cover wherein the pulley cover can be fastened to the window lifter rail in various positions. The advantages achieved with the invention are in particular that the window lifter rail can be flexibly adapted to respective operating conditions. One important advantage is that the pulley and the pulley cover can be adapted to a specific vehicle type only on site, the production of these components is not dependent on the vehicle type and may be automated. This results in a decrease in production costs. [0007] A compact assembly unit is made available in one embodiment, in which the window lifter rail is formed in one piece and the pulley and the pulley cover are directly fastened to the window lifter rail. [0008] It is preferred that a fastening plate is mounted to the window lifter rail, the pulley and the pulley cover being fastened to this fastening plate. This is why a pre-assembly of the pulley and the pulley cover on the fastening plate is made possible, and the pre-assembled unit can be fastened to a vehicle at a later point in time. [0009] Further, the pulley cover is preferably fastened or pre-fixed with hooks. Such hooks are commonly known as effective fastening elements that ensure a quick and reliable locking in place in the window lifter rail, and at the same time may be released quickly. Moreover, the production costs of such connections are low. [0010] It is preferred that for a tensile member, such as a Bowden cable for example, a required abutment for sheathing is immediately integrated in the pulley cover, whereby it is possible to ensure that the tensile member remains in associated grooves of the pulleys, in particular during installation on the vehicle. A slot provided in the abutment receives the tensile member. [0011] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 shows a schematic illustration of a cable pull type window lifter according to prior art. [0013] FIG. 2 is a perspective partial view of a front of a window lifter rail according to the present invention. [0014] FIG. 3 is a partial view of a rear of the window lifter rail according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0015] FIG. 1 schematically shows a traditional structure of a cable pull type window lifter 8 . A tensile member 10 is wound around a cable drum 12 and is coupled by the cable drum 12 to a cable drive (not shown). The tensile member 10 is guided in a closed loop over a lower pulley 14 and an upper pulley 16 . The lower and upper pulleys 14 , 16 are fastened to a window lifter rail 18 , and the tensile member 10 is provided with a sheathing at intermediate sections 38 between the lower and upper pulleys 14 , 16 and the cable drum 12 , if necessary. A driving dog 20 is connected with the tensile member 10 and with a window pane (not shown), so that the window pane can be moved upwards or downwards to a desired position by rotating the cable drum 12 . The exact function of a cable pull type window lifter 8 will not be discussed here, since it is known from prior art and the invention related to deflection of the tensile member 10 in a region of the lower and upper pulleys 14 , 16 . [0016] FIG. 2 shows a part of the window lifter rail 18 with the upper pulley 16 in a configuration incorporating the subject invention. The lower pulley 14 has a similar design. [0017] A fastening plate 22 is mounted to the window lifter rail 18 . The window lifter rail 18 is inserted in a pocket on the fastening plate 22 and is connected with the fastening plate 22 by a connecting element 24 , which is preferably a rivet or screw. [0018] The upper pulley 16 has a peripheral groove 26 adapted to guide the tensile member 10 . A pulley cover 28 is arranged over the upper pulley 16 and partially covers the upper pulley 16 . The upper pulley 16 and the pulley cover 28 are commonly fastened to the fastening plate 22 by a second connecting element 30 such as a screw or rivet. The upper pulley 16 is rotatably supported and the pulley cover 28 is immovably mounted to the fastening plate 22 by hooks 34 ( FIG. 3 ). [0019] The pulley cover 28 has an abutment 32 on one of its ends. The tensile member 10 has a sheathing 36 at the intermediate sections 38 ( FIG. 1 ) of the tensile member 10 . Ends of the sheathing 36 rest against the abutment 32 , because the tensile member 10 preferably is realized as a Bowden cable. As the use of a Bowden cable is known in this field, this will not be explained in further detail here. [0020] The tensile member 10 is guided generally in parallelism to the window lifter rail 18 and in the peripheral groove 26 of the upper pulley 16 . At the abutment 32 , the tensile member 10 leaves the upper pulley 16 and the pulley cover 28 in the desired direction. [0021] Upon actuation of the cable drive (not shown) the tensile member 10 is moved in a clockwise or counter clockwise direction, depending on the direction of movement of the window pane (not shown). In this process, friction of the tensile member 10 on the upper pulley 16 may virtually be neglected, because the upper pulley 16 is rotatably supported. [0022] FIG. 3 shows a rear of the window lifter rail 18 . The pulley cover 28 is fastened to the fastening plate 22 by hooks 34 . These hooks 34 engage in annular cut-outs 40 that are arranged in sections on the fastening plate 22 . [0023] The pulley cover 28 is assembled in the following manner. At first, the pulley cover 28 is pre-assembled on the fastening plate 22 by the hooks 34 . In so doing, the pulley cover 28 can be arranged in various positions (see the arrow in FIG. 2 ) without requiring a tool. If the pulley cover 28 is arranged with the desired angle, the pulley cover 28 is fastened in the respective position with the second connecting element 30 . In this way the desired deflection angle of the tensile member 10 (in this embodiment between 45° and 90°) can be adjusted. This is why the deflection angles, which vary depending on the vehicle type, can be altered without newly producing the individual components of the window lifter rail in an expensive way. [0024] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.	A window lifter rail includes a pulley and a pulley cover. The pulley cover can be fastened to the window lifter rail in various positions. This ensures an assembly unit that offers a more flexible use while also reducing the production and installation costs.	4
FIELD OF THE INVENTION The invention relates to a flat-iron comprising a fixed soleplate, means for heating the fixed soleplate, a thermostat for controlling the temperature of the fixed soleplate, and a movable soleplate hinged to the fixed soleplate by elastic means. A flat-iron with a movable soleplate makes it possible to rapidly lower the temperature of the soleplate that comes into contact with the fabric to be ironed by moving the movable soleplate away from the fixed soleplate. This precludes damage to the fabric in the case that the temperature of the fixed soleplate is too high. It also precludes burns as a result of contact with a soleplate having a high temperature. BACKGROUND OF THE INVENTION A flat-iron of this type is described in U.S. Pat. No. 2,076,614, which relates to a flat-iron having a fixed soleplate and a movable soleplate, which can either be brought into contact with or moved away from the fixed soleplate. The user can choose one position or the other position by means of a lever. When the lever is released the movable soleplate moves automatically away from the fixed soleplate under the influence of a spring arranged in a holder situated between the two soleplates. With such a flat-iron it is necessary that the user himself takes the step of actuating the lever in order to change the position of the movable soleplate. SUMMARY OF THE INVENTION It is the object of the invention to achieve that the user himself need not take this step of positioning the movable soleplate but merely restricts himself to normal use of the flat-iron. This object is achieved with a flat-iron comprising an electromagnet secured to the fixed soleplate, means for energizing the electromagnet, the movable soleplate being adapted to be attracted, at least locally, by the electromagnet, the elastic means being such that, firstly, they are capable of pushing the movable soleplate away from the fixed soleplate when the electromagnet is not energized and that, secondly, they allow the movable soleplate to be attracted by the electromagnet in order to be applied to the fixed soleplate when the electromagnet is energized. Thus, the tilting position of the movable soleplate is determined by the means for energizing the electromagnet. The rate at which the temperature of the movable soleplate decreases depends on the thermal mass of the movable soleplate. Preferably, a movable soleplate with a low thermal mass is chosen. The energizing means can take into account a state of use or non-use of the flat-iron. These energizing means may then comprise a detector for the state of use of the flat-iron, which detector deenergizes the electromagnet when the flat-iron is not in use. The state-of-use detector is, for example, an electrical switch actuated when a user holds the flat-iron, or any state-of-use detector which detects a motionless state of the flat-iron. The energizing means can also take into account settings of the flat-iron, for example of the thermostat, selected by the user, the energizing means detecting whether the settings thus selected are compatible or not compatible with the nature of the fabric on which the flat-iron is placed. In that case, in a first variant, the energizing means may comprise a nature-of-fabric detector which deenergizes the electromagnet when the thermostat has settings which are not compatible with the nature of the fabric. In a second variant the energizing means may comprise a nature-of-fabric detector which energizes the electromagnet when the thermostat has settings which are compatible with the nature of the fabric. The energizing means may combine the action of the state-of-use detector and that of the nature-of-fabric detector. Alternatively, said means may separately use one detector or the other detector. BRIEF DESCRIPTION OF THE DRAWINGS These and still other aspects of the invention will become apparent from and elucidated by means of the following description of embodiments. The invention will be more fully understood with the aid of the following Figures given by way of non-limitative examples, in which: FIG. 1 shows a flat-iron in accordance with the invention. FIG. 2 is a diagram of the electrical part comprising the electromagnet and the energizing means for the electromagnet. FIG. 3 is an enlarged view of a section of a soleplate provided with a thermally conducting coating. DESCRIPTION OF EMBODIMENTS FIG. 1 shows a flat-iron 5 comprising a fixed soleplate 10, a movable soleplate 14, a body 19 and a handle 20. The movable soleplate 14 preferably has a low thermal mass, for example by giving it a small thickness. The iron further comprises heating means 22 for the fixed soleplate and a thermostat 24 for controlling the temperature of the fixed soleplate. The fixed soleplate and the movable soleplate are hinged to one another about a hinge 15. The latter may be arranged at the rear, at the front or on a side of the soleplate of the flat-iron. Springs 16, which are preferably formed by a steel blade, are arranged between the two soleplates to vary the spacing between them. One of the ends of each blade is secured to one of the two soleplates, the other end being free to move depending on the variations of the spacing between the two soleplates. In the non-spaced position the springs engage in recesses 17 to allow contact between the two soleplates. It is possible to use other elastic means, for example spiral springs. The movable soleplate 14 is partly or wholly made of a ferromagnetic material (for example, soft iron). For example, an element 13 of a ferromagnetic material may be arranged in a movable soleplate made of a non-magnetic material on the basis of aluminum. A nose 18 enables the fixed soleplate 10 to engage in the movable soleplate 14. The fixed soleplate 10 is provided with the electromagnet 12, which is flush with the surface of the fixed soleplate 10 facing the magnetic element 13 arranged in the movable soleplate. By energizing the electromagnet 12 this magnet can attract the magnetic element 13 and bring the two soleplates into contact with one another, as a result of which the movable soleplate is heated by the fixed soleplate. It is possible to use a plurality of electromagnets. FIG. 2 shows the electromagnet 12 arranged opposite the magnetic element 13. The electromagnet 12 comprises coils 28, 29 connected in series with a power supply source V via energizing means 25 for said coils. The energizing means 25 comprise a switch 26, which can be closed or opened by a detector 27 for respectively energizing or deenergizing the coils of the electromagnet. The energizing means 25 can be of different types. The detector 27 may be, for example, a state-of-use detector. This is, for example, an electrical switch 11 (FIG. 1) arranged in the handle of the flat-iron to energize the coils 28, 29 when a user holds the flat-iron. The state-of-use detector may alternatively be a motion detector which detects movements of the iron. Such a detector is described, for example in European Patent Application EP 0,523,794 A1. It is an electrostatic detector which measures the amount of electrostatic charges produced in a fabric as the flat-iron moves over the fabric. Detectors with tilting elements, such as those in which a drop of mercury tumbles, may be used or any other type of state-of-use detector. It may be, for example, a detector which detects the motionless state of the iron when placed with its fixed and movable soleplates in a vertical position. In this position the risk of burning is highest. In the case that a state of non-use of the flat-iron is detected, both in a horizontal position and in a vertical position of the iron, the energizing means 25 deenergize the electromagnet, which causes the movable soleplate to be moved away and to cool rapidly, which protects the fabric against damage by overheating and/or precludes bunting. A visual or acoustic indicator may be activated to warn the user. The energizing means 25 may include a timing to set the instant at which the mechanisms are activated. When the iron is not connected to an electric power supply the security as a result of the spacing between the two soleplates remains operative. The detector 27 may be a nature-of-fabric detector, for example the detector described in European Patent Application EP 0,523,794 A1. It is an electrostatic detector which determines the nature of the fabric depending on the amount of electrostatic charges produced in a fabric as the flat-iron moves over the fabric. For the purpose of protecting the fabric two variants may be envisaged. In a first variant the user sets the thermostat and starts ironing, the two soleplates being in contact with one another. The nature-of-fabric detector then determines the nature of the fabric and decides if the settings selected by the user are compatible or not compatible with the detected nature of the fabric: synthetics, cotton, silk . . . If the settings are not compatible the energizing means 25 deenergize the electromagnet, causing the movable soleplate to be moved away and to cool rapidly. This tilting movement warns the user of the detected incompatibility, enabling him to take action by selecting new thermostat settings. For an additional warning of the user a visual or acoustic indicator may be activated. In the second variant the nature-of-fabric detector activates the electromagnet only when the settings of the flat-iron are compatible with the detected nature of the fabric. For this purpose, ironing is started with the movable soleplate spaced from the fixed soleplate. Thus, even with a fixed soleplate having a high temperature, the movable soleplate will remain at a low temperature, which does not cause any damage to the fabric. The nature of the fabric can then be detected by the nature-of-fabric detector, which also determines if the settings of the thermostat selected by the user are compatible or not compatible with the detected nature of the fabric. If the settings are compatible, the energizing means energize the coils of the electromagnet, as a result of which the movable soleplate is tilted against the fixed soleplate. In the opposite case, this tilting does not take place. The fact that no tilting takes place may be enough to warn the user of the detected incompatibility. In addition to this, a visual or acoustic indicator may be activated. To improve the quality of the thermal contact between the movable soleplate and the fixed soleplate a thermally conducting coating may be provided on either of the soleplates. This may be a thin layer consisting of, for example, a polymer loaded with a thermally conductive material (loaded silicone). Preferably, the coating has an elasticity which is adequate to ensure that the movable soleplate engages correctly with the fixed soleplate. FIG. 3 shows an enlarged view of a section of the soleplate 14 provided with a layer 30 of such a thermally conductive coating.	A flat-iron (5) comprises a fixed soleplate (10) against which a movable soleplate (14) is engageable in order to guarantee a safe use both for the user and for the fabric to be ironed. The soleplate (14) can be brought into contact with the fixed soleplate (10) with the aid of an electromagnet (12), which is controlled by a state-of-use detector (11) and/or a nature-of-fabric detector (27) coupled to the thermostat.	3
FIELD OF THE INVENTION This invention is directed to a method for the recovery of sulfur from a slurry containing same. BACKGROUND OF THE INVENTION When recovering hydrogen sulfide from oil sour gas, hydrogen sulfide is usually oxidized to elemental sulfur. One process which can be utilized is based on the use of ferric ions in an alkaline solution and may be represented by the following equation: H.sub.2 S.tbd.HS.sup.- +H.sup.+ HS.sup.- +2 Fe.sup.+++ →S.sup.O +2 Fe.sup.++ After the formation of elemental sulfur, the reduced oxidant, Fe ++ , is oxidized by blowing air to Fe +++ . In one process for recovering sulfur, the sulfur recovery section includes a settling tank and a melter-settler. In the sulfur melting step, oxidant loss, sulfur discoloration and plugging have been observed and are undesirable. In order to avoid the undesirable consequences of melting the sulfur, it is possible to recover the sulfur by separation from the mother liquor by filtration or centrifugation. However, for such separation techniques to be effective, it is desirable to have a sulfur slurry with a fairly consistent solids content of about 20 weight percent. During the airblowing step previously mentioned, where Fe ++ is oxidized to Fe +++ , the sulfur and the mother liquid becomes a "froth". Since the flow of hydrogen sulfide into the process is variable, the concentration of sulfur in the froth varies from less than about 1 wt. % to about 20 wt. %. Therefore, what is needed is a method to produce a uniformly consistent concentration of sulfur in a slurry which will settle in a reasonable amount of time in order to avoid the undesirable consequences of melting the sulfur. SUMMARY OF THE INVENTION This invention is directed to a method for concentrating sulfur suspended in a liquid medium by the use of a clay. To accomplish this, clay is mixed with the sulfur suspended in the liquid medium for a time sufficient to obtain proper mixing. After mixing, the mixture is allowed to settle for from about 2 to about 5 hours at a temperature of from about 24° C. (75° F.) to about 45° C. (113° F.). After the sulfur has separated from the liquid medium, the liquid medium or mother liquor is removed from the consolidated sulfur which has settled. Prior to removing the mother liquor, the sulfur settles in a preferred amount of about 15 to about 40 wt. % sulfur. After the mother liquor has been removed, the sulfur which has settled is either centrifuged or filtered. If the sulfur which has settled is in a concentration of about 35 to about 45 wt. %, the sulfur and the slurry can be removed and sold commercially. In a preferred embodiment, the clay comprises bentonite which is mixed with the liquor containing the suspended sulfur in an amount from about 750 ppm to about 1200 ppm, preferably about 1000 ppm. The mixture is maintained at a temperature of from about 10° C. (50° F.) to about 45° C. (113° F.). After a settling time of from about 0.25 hours to about 5 hours, the sulfur is concentrated to from about 25 to about 45 wt. %. The mother liquor is removed from the mixture. However, if the mixture contains from about 40 to about 45 wt. % sulfur, the mixture is in a concentration which can be transported and sold commercially. If the concentration of the sulfur is less than from about 15 to about 30 wt. %, the sulfur is removed from the slurry by centrifugation or filtration. The mother liquor is then removed and recycled for further processing. It is therefore an object of this invention to obtain an undiscolored sulfur. It is a further object of this invention to avoid the melter-settler step with this attendant oxidant loss and associated plugging problems. It is a still further object of this invention to reduce the volume of sulfur slurry and avoid containment problems. It is a yet further object of this invention to concentrate sulfur slurry in an amount sufficient for economical transportation and coamercial sale. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph which depicts the settling and concentration times of a 5% sulfur slurry. FIG. 2 depicts a clay mixing and suspended sulfur settling process for sulfur separation. FIG. 3 depicts a clay mixing and suspended sulfur settling process for facilitating the commercial sale of sulfur. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hydrogen sulfide can be separated from sour gases by selective removal using alkali liquids. The alkali liquids may be selected from many aqueous solutions of hydroxides, organic basis, such as alkanolamines, alkanoldiamines and alkenylpolyamines. Alkali metal hydroxides and alkanolamines are preferred, particularly diethanolamine and N-methyldiethanolamine, which show high selectivity towards hydrogen sulfide and not carbon dioxide. Pursuant to this separation, elemental sulfur is formed by oxidation of the hydrogen sulfide. After the formation of elemental sulfur, the reduced oxidant is oxidized for re-use. When ferrous ions are the reduced species they are oxidized by blowing with air to make ferric ions. During the air blowing step, where ferrous ions are oxidized to ferric ions, the sulfur in the mother liquid becomes a "froth". When or if the flow of hydrogen sulfide into the process is variable, the concentration of sulfur in the froth will vary from less than about 1 wt. to about 20 wt. %. In order to avoid the low concentration of sulfur in the slurry, the sulfur contained in the froth is concentrated so as to avoid storage problems. In the practice of this invention, referring to FIG. 2, a solid floculating agent, preferably a clay for example, ball clay or bentonite, is mixed in tank 10 in an aqueous solution. From tank 10 the clay mixture is led via line 12 into a mixing T where it mixes with the sulfur froth coming through line 14. The sulfur froth is of a concentration of from about 1 wt. % to about 5 wt. %. Upon mixing with the sulfur froth, the mixture containing the clay is led via line 16 into tank 18 where it is allowed to settle at a temperature of from about 10° C. (50° F.) to about 45° C. (113° F.), preferably about 42° C. (108° F.). The mixture is allowed to remain in the tank for a time sufficient to obtain settling of the sulfur. Generally this will be from about 0.25 hours to about 5 hours, preferably about 2 hours. FIG. 1 shows a graphical illustration of these results. After the sulfur has settled to the desired concentration, the mother liquid is removed from the tank via line 22 where it is recycled back into the process. Depending upon the operating conditions, the slurry can be allowed to concentrate at from about 20 wt. % to about 45 wt. %, preferably about 40 wt. %. Where it becomes necessary, a sulfur slurry containing from about 15 wt. % to about 25 wt. %, preferably about 20 wt. %, can be removed from tank 18 by line 26 where it will undergo centrifugation or filtration to remove excess water therefrom. This is shown in FIG. 2. Where operating conditions permit, the sulfur slurry can be concentrated and consolidated up to about 45 wt. %, where it can then be removed along with the water and sold commercially. This is shown in FIG. 3. In order to obtain the optimum results for concentrating the sulfur slurry, it is preferred to have the solid flocculating agent added into the slurry, containing about 5 wt. % sulfur, in an amount of from about 750 ppm to about 1250 ppm, preferably about 1000 ppm. The most effective temperature at which to conduct the sulfur concentration and consolidation is at from about 10° C. (50° F.) to about 42° C. (108° F.). In another emodiment of this invention, the sulfur slurry containing about 5 wt. % sulfur is mixed with bentonite and a liquid polymer flocculating agent. Suitable liquid polymer flocculating agents can be obtained from commercial producers as is known to those skilled in the art. For example, a suitable agent is the Magnifloc™ polymer obtainable from American Cyanaxid located at Wyyne, N. J. When preparing a bentonite/Magnifloc polymeric flocculant mixture, the method of preparation will have a significant and critical effect upon the results obtained in the process. To obtain the best results, a 10 wt. % bentonite paste is mixed with water. This mixture is then combined with a required amount of Magnifloc flocculant solution in water with the paste in an amount of from about 0.001% by weight to about 0.2% by weight. One part of this mixture is then diluted with nine parts of water. The resultant mixture is subsequently combined with the sulfur slurry. Afterwards, the process is conducted as mentioned above to obtain the desired concentration and consolidation of sulfur from the slurry. For optimum results, about 1000 ppm of bentonite and about 10 ppm of Magnifloc E-1285 liquid polymer flocculant should be added to the 5 wt. % sulfur slurry. As is known to those skilled in the art, Magnifloc E-1285 polymer is a highly active, high molecular weight, high cationicity, liquid flocculant often used in sludge conditioning and waste treatment processes. After mixing with said slurry, a 20% sulfur slurry is produced in less than about 2 hours. This combination gives a consolidated sulfur layer. Furthermore, no sulfur adheres to the walls of the vessel. Referring to FIG. 1, the relationship between the estimated concentration time of a 5 wt. % sulfur slurry is depicted. As shown in FIG. 1, most of the sulfur forms a precipitate in a short time and the preciptate then consolidates into a more compact layer. After about one hour, further compaction is minimum. Even upon standing for about 24 hours, the sulfur concentration in the consolidated sediment increases only from about 40% by weight to about 50% by weight. The examples which follow show the effectiveness of the process described above. EXAMPLE 1 A 25 ml sample of 5% sulfur froth was allowed to stand at 42° C. (108° F.) for a period of about eight hours. Little or no settling was observed in the settling vessel. EXAMPLE 2 A 22.5 ml sample of a 5 wt. % sulfur froth was mixed with 2.5 cc of a slurry made from 1% by wt. Tennessee Ball Clay #10 and the mixture allowed to stand for about 5 hours at 42° C. (108° F.). The sample separated into a 6 ml layer containing about 20 wt. % sulfur and a mother liquor containing 0.4 wt. % sulfur. EXAMPLE 3 A 22.5 ml sample of a 5 wt. % sulfur froth was mixed with 2.5 ml of a 1% by wt. slurry made from 10% by wt. bentonite paste and the mixture allowed to stand for about 5 hours at 42° C. C. (108° F.). The sample separated into a 6 ml layer containing 20 wt. % sulfur and a mother liquor containing 0.4 wt. % sulfur. EXAMPLE 4 A repeat of Example 3, however, the temperature was 24° C. (75° F.). The same result was observed as that of Example 3. EXAMPLE 5 A 22.5 ml sample of a 5 wt. % sulfur froth was mixed with 2.5 ml of a solution which had a flocculant concentration of 0.001 wt. % and the mixture allowed to stand at 42° C. (108° F.). No separation was observed. EXAMPLE 6 A 22.5 ml sample of a 5% wt. sulfur froth was mixed with 2.5 ml of a 1% by wt. slurry made from 10% by wt. bentonite, which had been impregnated with 0.01 wt. % of the same chemical flocculant used in Example 5, and the mixture allowed to stand at 42° C. (108° F.). In less than one hour a 6 ml layer equivalent to about 1/4 the volume of the test container developed. This corresponds to a 4-fold concentration of the sulfur, i.e. about 20 wt. %. After a 2-hour settling period, this layer became more dense and occupied a volume which corresponded to about 1/8 the volume of the test container. This layer of sulfur contained about 40% by weight sulfur and the mother liquor contained about 0.7% by wt. sulfur. Although the present invention has been described with preferred embodiments and examples, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims.	A sour gas obtained from an enhanced oil recovery is converted to sulfur slurry which is concentrated for easy filtration, or for direct disposal, by the addition of substantially small amounts of a solid flocculating agent e.g. clay, optionally in combination with selected suitable conventional liquid polymer flocculants. For this purpose, bentonite has been shown to be a particularly effective solid flocculating agent.	2
BACKGROUND OF THE INVENTION This invention relates to automatic machinery and more particularly to automatic machinery for handling cloth and similar flexible materials. There have been many attempts to devise methods by which flexible materials may be handled automatically. In general, it has proven relatively easy to handle a material such as cloth while it remains in its uncut form. However, once material has been cut into small or any sort of irregular shape, its light weight, flexibility, stretchability, surface texture, and other characteristics make it very difficult to handle in a useful manner. Because of its high labor intensity and the high cost of that labor, the sewing industry is especially ready for such automatic machinery. There are special purpose machines on the market each of which is adapted to accomplish one specific sewing operations over and over. Such machines are very expensive and suited to only the limited special purposes for which they were designed. To broaden the range of operations, attempts are being made to build robots which may be programmed to perform the many operations of a human operator of a sewing machine. One of the main difficulties has been in providing a device with extreme sensitivity of touch and many degrees of freedom which is capable of simulating the human hand. To date there has been no hand simulator (called an "end effector") found practical to replace the human operator's hands in the automatic sewing of the many types and qualities of materials which must be handled. There have been devices which use needles adapted to project through a base into some portion of a layer of material in order to handle that material, e.g., see Canadian Apparel Manufacturer, pp. 11-18, June 1983, by Frank W. Paul. Theoretically, such a device will work but in actuality there are no industrial sewing machines using such devices because they cannot be made to work reliably. For example, needles have such a shape that they penetrate to essentially an unlimited depth in most materials. Consequently, the depth of penetration must be adjusted so that a particular needle penetrates only a selected thickness of the particular material with which it is to be used. If the adjustment is slightly off, then the needle penetrates either too deeply or too shallowly. If the needle penetrates too deeply, it may break or bend on the surface against which the material is urged; and the device ceases to operate. Alternatively, if the needle penetrates too shallowly, it is not able to secure the material and the device does not operate. (See statistics from above noted article.) Moreover, needles must be adjusted for each particular thickness of material. For example, if it is desired to pick up a single layer of material and the needles of the end effector project too far, they pass through the piece of material and pick up more than the desired single layer. Thus, while the theory of using needles to handle flexible material such as cloth is quite good, the result is that such devices are unreliable; and the use of labor has been found to be cheaper. It is, therefore, an object of this invention to provide an end effector which may be used with industrial robots for handling flexible materials. It is another object of this invention to provide a device which will handle all types of flexible materials. It is another object of this invention to provide a device which will handle materials in many different opeations. It is an additional object of this invention to provide a device which will handle varying thicknesses of materials. It is yet another object of this invention to provide a device which is capable of handling flexible material such as cloth inexpensively and rapidly. SUMMARY OF THE INVENTION The foregoing and other objects of this invention are provided in a device which utilizes barbs as pickup devices. The barbs project from shanks which are mounted to arms connected to piston shafts which force them to protrude from a baseplate and project into the material to be handled. By using sets of barbs mounted so that they may be made to project in opposite directions into a piece of flexible material, opposing forces may be placed at separated positions in a piece of material so that the material can be picked up, moved from place to place, rotated, inverted, and otherwise handled as though by a human hand. Since a barb is a sharply angled pointed projection from a shank, both the angle of the point of the barb and the distance to the shank itself limit the amount by which the barb may project into a particular piece of material. Because of this limiting feature, one size of barb may handle many varieties and thicknesses of materials without significant adjustment. The invention will be better understood by reference to the detailed specification and the drawings in which like reference numerals designate like elements throughout the several views. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a device constructed in accordance with the present invention utilized for handling materials; FIG. 2 is an enlarged front view of a fragment of FIG. 1; FIG. 3 is a bottom view of the enlarged portion shown in FIG. 2; FIG. 4 is a side view of another embodiment of the invention; FIG. 5 is an enlarged view of a detail of the arrangement shown in FIG. 4; FIG. 6 is a perspective view of a device constructed in accordance with the invention which may be utilized for moving flexible materials from place to place; and FIG. 7 is an exploded perspective view, partially cutaway, of another embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown a material handling device 10 constructed in accordance with the invention. The device 10 has a baseplate 12 which may be constructed of a material such as aluminum plate. The plate 12 should be sufficiently thick and of such an alloy that it does not bend in heavy usage. The plate 12 has mounted thereon (such as by screws, not shown in FIG. 1) a first and a second holder 14 and 16, respectively. The holders 14 and 16 may be constructed of a material such as a plastic which may be provided with a slick surface. Each holder has a passage 17 therein (see FIG. 2) in which is mounted a pneumatic cylinder 18 or 20, respectively. In the embodiment shown, the passages 17 are cylindrical holes adapted to fit closely about the outsides of the cylinders 18 and 20. Each particular cylinder 18 or 20 provides the impetus for actuating the device 10. Each of the pneumatic cylinders 18 and 20 has a shaft 22 mounted to a piston carried in a chamber in the interior thereof in a manner well known to the prior art. These shafts 22 (only one of which, is shown in FIG. 1) are driven outward from the cylinders 18 and 20 along the axis of each of the cylinders when air or other gas is provided by means such as by an airline 24 through an inlet 26 connected to the interior chamber of the particular cylinder 18 or 20. Thus, the provision of air at a selected pressure through the airline 24 causes the shaft 22 to move in the direction of the arrow shown on the near face of the holder 14 in FIG. 1. Although the inventor's assignee manufactures its own pneumatic cylinders which are not sold, pneumatic cylinders of the same type are manufactured by Clippard Instrument Laboratory, Inc., 7390 Colerain Road, Cincinnati, Ohio. A Clippard SM-2 cylinder may be used in the present invention. Such cylinders are normally constructed of aluminum alloy and are quite light in weight. Cylinders operated by other means, such as solenoids and other mechanical means, might be used to obtain the same movement of a shaft which is used, as will be explained hereinafter to drive barbs into flexible material. However, the aluminum pneumatic cylinders used in the preferred embodiment tend to lighten the device, especially when used in conjunction with a pneumatic actuating arrangement, and make it much more rapid in use. In the embodiment shown in FIG. 1, a thin opening or slot 25 is provided in each particular holder 14 and 16 so that the cylinders 18 and 20 may be clamped in place as by a screw 27. The slot 25 and the screw 27 allow the cylinders 18 and 20 to be moved axially so that the position to which each shaft 22 extends may be conveniently adjusted and the cylinders 18 and 20 may be readily removed from the holders 14 and 16. The shaft 22 is affixed to an arm 28 which is mounted to slide in a groove 30 in the holder 14. The arm 28 is fashioned from a flat plate in the embodiment of FIG. 1 and may be of metal construction. The arm 28 is polished so that it slides easily. The groove 30 is fashioned to have a shape (generally rectangular in the embodiment shown in the Figures) to fit closely around the arm 28 on all but one side so that the arm 28 may slide freely therein with the movement of the shaft 22. The open side of the groove 30 allows easy removal of the arm 28 when it is desired to change barbs as is explained below. The groove 30 is also polished internally in the preferred embodiment; thus the movement of the shaft 22 causes the arm 28 to move in the direction of the arrow shown on the face of the holder 14. FIG. 2 is a side view of the holder 14 mounting an arm 28 therein and having a cylinder 18 adapted to move the arm 28 in the direction shown by the arrows thereon. The arm 28 has a lower portion which projects downwardly at approximately a right angle to its main body; this lower portion has a bottom surface 32. As may be seen in FIG. 2, the shaft 22 projecting from the cylinder 18 and the arm 28 are inclined at approximately ten degrees to the lower surface of the plate 12. Thus, as the arm 28 moves outwardly from the cylinder 18, the bottom surface 32 thereof is directed downwardly through an opening 34 (see FIG. 1) in the plate 12. Mounted to the bottom surface 32 of the arm 28 is a shank 36 having a pair of barbs 38 projecting therefrom. In operation, the plate 12 is placed on top of a piece of material, such as a piece of cloth, by a device such as a computer-actuated robot capable of moving the plate 12 in three dimensions; many such devices are known to the prior art. Air or some other gas is applied through the air lines 24 to the two cylinders 18 and 20, forcing the shafts 22 outwardly and causing the arms 28 to move in the grooves 30 carrying the barbs 38 down at an angle through the openings 34 to the dotted position shown in FIG. 2 against the material. This causes the barbs 38 to pierce the material and stretch it outwardly along the axis of the plate 12. The length of the movement of the shafts 22 is adjusted so that the material is held firmly in place and may be lifted, moved, held in a new place, sewn, and otherwise handled as though by a human hand. Each of the cylinders 18 and 20 may be conveniently provided with a return spring so that when air pressure is removed from the airlines 24 feeding the cylinders 18 and 20, the shafts 22 retract, drawing with them the arms 28 and causing the barbs 38 to release the material previously secured thereby. In this manner the material may be deposited as desired after any use. FIG. 3 is a bottom view of the holder 14 shown in FIG. 2 and illustrates the position of the two barbs 38 fixed to the shank 36 and to the arm 28. The shank 36 may be soldered, welded, crimped into position in a groove in the surface 32 or otherwise fixedly secured on and parallel to the pick-up accommodating surface 32 as shown in FIG. 2. As may be seen from FIG. 3, the two barbs 38 are each quite broad at the base (as broad as the shaft in the example shown) and come to a sharp point at the tip. The large angle of the point of such a barb causes its insertion into a particular material to be self limiting in the sense that it may enter a piece of material only until the width of the barb is too large to fit between the interstices of the particular material. Furthermore, the shank 36 from which the barbs 38 protrude provides an ultimate limitation to entry of the barbs 38 into a material. Consequently, the barbs 38 may enter a material used with the device 10 only to the depth provided by the dimensions of the barbs and the interstices of the material itself, a depth ultimately limited by the dimension from the point of each barb 38 to the shank 36. Because of this limiting effect, the device 10 need not be closely adjusted for each type of material with which it is used. Moreover, because the barbs need not be closely adjusted, they do not work their way out of adjustment easily during use, in contrast to prior art devices utilizing needles driven at an angle into material such as are disclosed by the above-mentioned article. As may be understood, when a needle is directed into a piece of material, its narrow dimension allows it to progress through most materials without halt. Consequently, the length of movement of a needle must be carefully adjusted or it will travel too far into a material, piercing a number of layers and thereby mishandling the material. Alternatively, if a needle is maladjusted so that it protrudes insufficiently into material, the material may easily drop off and again be mishandled. An especially undesirable feature of a needle is its tendency to scratch surfaces lying underneath the material upon which work is to be accomplished or its tendency to bend rendering the entire device inoperative. The self limiting feature of the barbs used in this invention is consequently quite desirable in a material handling situation. FIG. 4 illustrates another embodiment of the invention in which a hook 50 is mounted to the shaft 52 of a pneumatic cylinder 54. The hook 50 is especially useful when a number of materials are to be handled together such as a fabric 56 and a thickness of foam 58. The hook 50 has the self limiting feature of a barb in that the bight of the hook provides a limiting depth to which the hook 50 may be driven. Consequently, when thick materials such as foam layers are used, it is quite useful and is able to handle larger and heavier loads than is a barb. FIG. 5 shows a device 51 to which a hook 50 may be attached which may be itself attached to a shaft 52 of a cylinder 54 and used in the arrangement 48 shown in FIG. 4. In a preferred embodiment, the hook 50 has a shape which is a section of a circle generally less than one half of the circle. This provides a fairly large upper surface through which lifting force may be applied to a material, such as a foam material, to allow it to conveniently handle such a material. FIG. 6 illustrates a device 60 which may be used for picking up and moving about a square piece of material. The device 60 includes a baseplate 61 and four individual holders 62 each of which is provided with a set of barbs such as those shown in the arrangement of FIG. 1. Openings (not shown) are provided below each of the holders 62 in the baseplate 61 so that the barbs may be driven therethrough and into a material 63 positioned therebelow upon which the baseplate 61 lies. An arm 64 is shown connected at a pivot 65 to the baseplate 61 for moving the baseplate from place to place. It will be understood by those skilled in the art that the arm 64 and its attachment to the baseplate 61 are only exemplary and that normally a much more complicated arrangement would be used. As is shown in FIG. 6, each of the holders 62 is positioned so that the barbs protruding from its base are positioned at 90 degree intervals around the center of the baseplate 61. Consequently, when air is provided to each of a series of cylinders 66 supported within the holders 62, the barbs, not shown in FIG. 6, will be driven into the material 63 postioned below the baseplate 61, stretching it in four directions and flattening it, so that the material may be raised and otherwise moved about to the particular position desired in the particular automatic operation. FIG. 7 illustrates another end effector 70 which is especially useful in handling very thin pieces of material. The end effector 70 includes a cylinder 71 which receives air or other gas through an inlet 72 and drives a shaft 73 in the direction of the arrow shown on the side of a block 74. The block 74 may be of a plastic material and have a cylindrical hole 75 therethrough through which projects and is secured the front of the cylinder 71. The shaft 73 protrudes from the end of the cylinder 71 and has an end 77 which projects into and supports a block 78. The block 78 may be constructed of material such as a lightweight plastic and secures a pair of shaped rods 79 from which depend barbs 76. Opposite ends of the rods 79 are embedded in the block 78 in the embodiment shown in FIG. 7 but might be secured therein by other means well known to those skilled in the art. The end effector 70 is made to fit down into a channel 80 having a generally U-shape. The channel 80 may be constructed to accommodate a number of individual end effectors 70, but only one portion thereof is shown. The channel 80 may be constructed of a material such as a thin lightweight aluminum and may have a pair of grooves 81 in the lower surface thereof through which the rods 79 may partially extend so that the barbs 76 project from the lower surface of the channel 80. The dimensions of the end effector 70 are such that the lower surface of the block 74 rides on an upper surface 82 of the base of the channel piece 80; the block 74 is held in place by a pin (not shown in FIG. 7) which may be inserted through holes 83 in the channel 80 and 84 in the block 74 to securely position the block 74 within the channel piece 80. When so positioned, the lower surface of the block 74 will ride on the surface 82 causing the barbs 80 to project through the lower surface of the channel piece 80 at a prescribed distance below that surface. Such an end effector 70 when used with the channel piece 80 is very useful with extremely thin pieces of material. For example, when the cylinder 71 is operated to drive the shaft 73 outwardly in the direction of the arrow, the barbs 76 which project slightly below the surface of the channel piece 80 are driven in the direction of the arrow and down into any material thereunder. Releasing the gas pressure provided through the inlet 72 allows the barbs 76 to withdraw from the material so that it may be released. As will be understood by those skilled in the art, various other arrangements than the preferred embodiment may be used for constructing material handling devices such as those shown in this specification without departing from the teachings of the invention. It is, therefore, to be understood that it is the intention of the inventor to be limited only by the scope of the claims appended hereto.	An end effector for use with automatic machines for handing flexible materials including a flat base plate having openings therein, at least two barbs, holders positioning each of said barbs adjacent one of said openings, an arrangement for moving each of said barbs through the adjacent one of the openings along a path which forms an angle of less than forty five degrees with the face of the plate, the arrangement for moving each of the barbs through the adjacent one of the openings limiting the travel of the barb along the path and being adapted to move each of the barbs in a direction generally opposite to the directions of the path.	1
This application is a divisional application of Ser. No. 08/479,107, filed Jun. 7, 1995, now U.S. Pat. No. 5,763,250, which is a continuation of Ser. No. 08/231,397, filed Apr. 22, 1994, now U.S. Pat. No. 5,616,482, which is a continuation of Ser. No. 07/886,715, filed May 21, 1992, now abandoned, which is a continuation of Ser. No. 07/537,430, filed Jun. 13, 1990, now abandoned, which is a continuation-in-part of Ser. No. 07/488,608, filed Mar. 2, 1990, now abandoned. BACKGROUND OF THE INVENTION This invention relates to the use of recombinant DNA techniques to construct chimeric toxin molecules. The literature contains many examples of fused genes which code for chimeric proteins. For example, Villa-Komaroff et al. (1978) Proc. Natl. Acad. Sci. U.S.A. 75:3727-3731, describes a fused gene made up of a eukaryotic structural gene fused to a non-cytoplasmic bacterial gene. The fused gene codes for a chimeric protein which is transported out of the cytoplasm. Murphy U.S. Pat. No. 4,675,382, hereby incorporated by reference, describes the use of recombinant DNA techniques to produce a hybrid, or chimeric, protein, consisting of a portion of the diphtheria toxin (DT) molecule linked via a peptide linkage to a cell-specific ligand such as α-melanocyte stimulating hormone (MSH). The DT-MSH chimeric toxin was selectively toxic for particular target cells, i.e., α-MSH receptor positive human malignant melanoma cells. A diphtheria toxin-related fusion protein, DAB 486 -IL-2, in which the native receptor binding domain of DT was genetically replaced with a portion of the polypeptide hormone interleukin-2 (IL-2) has been described in Williams et al. (1987) Protein Engineering 1:493-498, hereby incorporated by reference. DAB 486 -IL-2 is a 68,142 Da fusion protein consisting of, in the following order: Met; DT residues 1-485; and amino acids 2 through 133 of mature human IL-2. DAB 486 -IL-2 has been shown to bind to the IL-2 receptor and to selectively intoxicate lymphocytes which bear the high affinity form of the IL-2 receptor, Bacha et al. (1988) J. Exp. Med 167:612-622. Moreover, the cytotoxic action of DAB 486 -IL-2, like that of native diphtheria toxin, requires receptor-mediated endocytosis, passage through an acidic compartment, and delivery of Fragment A associated ADP-ribosyltransferase to the cytosol of target cells, Bacha et al. (1988) supra. SUMMARY OF THE INVENTION In general, the invention features a chimeric toxin including protein fragments joined together by peptide bonds. The chimeric toxin includes, in sequential order, beginning at the amino terminal end of the chimeric toxin: (a) the enzymatically active Fragment A of diphtheria toxin; (b) a first fragment including the cleavage domain 1 1 adjacent Fragment A of diphtheria toxin; (c) a second fragment including at least a portion of the hydrophobic transmembrane region of Fragment B of diphtheria toxin, the second fragment also having a deletion, C-terminal to the transmembrane region, of at least 50, or more preferably of at least 80, diphtheria toxin amino acid residues, and the second fragment not including domain 1 2 ; and (d) a third fragment including a portion of a cell-specific polypeptide ligand e.g., an interleukin (preferably interleukin 2, or, epidermal growth factor (EGF), including at least a portion of the binding domain of the polypeptide ligand, that portion being effective to cause the chimeric toxin to bind selectively to a predetermined class of cells to be attacked by enzymatically active Fragment A. In preferred embodiments the chimeric toxin possesses at least one of, and more preferably at least two of, and even more preferably at least three of: greater toxicity to receptor-bearing cells than that of an analagous DAB 486 -containing-toxin (an analagous DAB 486 -containing toxin is a toxin which is identical to the chimeric toxin of the preferred embodiment except that DAB 486 replaces the fragments of DT recited in (a), (b), and (c) above, i.e., a toxin consisting of DAB 486 fused to the fragment defined in (d) above); a lower K d (i.e., a greater binding affinity) for the receptor (i.e., the sites to which the third fragment (described above) binds on the cells to be attacked) than that of an analagous DAB 486 -containing-toxin; greater resistance to proteolytic degradation than that of DAB 486 -containing-toxin; greater resistance to the inhibition of its cytotoxicity by competitive inhibitors, e.g., the polypeptide of (d) above, than that exhibited by an analagous DAB 486 -containing-toxin; the ability to inhibit protein synthesis in target cells to a given degree by a period of exposure that is shorter than the period of exposure required by an analogous DAB 486 -containing-toxin to inhibit protein synthesis to the same degree; or the ability to effect a more rapid onset of the inhibition of protein synthesis than that seen in an analagous DAB 486 -containing-toxin. Other preferred embodiments include: chimeric toxins wherein the fragment of Fragment B of diphtheria toxin does not include any diphtheria toxin sequences between the hydrophobic transmembrane region and amino acid residues 484 or 485 of native diphtheria toxin; chimeric toxins lacking diphtheria toxin sequences C-terminal to amino acid residue 386 of native diphtheria toxin; and chimeric toxins including DAB 389 fused to the third fragment defined above. Other preferred embodiments include: a chimeric toxin in which the portion of the polypeptide ligand is a portion of interleukin-2 effective to cause the chimeric toxin to bind to IL-2 receptor bearing cells, in particular, T cells; a chimeric toxin in which the portion of the polypeptide ligand is a portion of EGF effective to cause the chimeric toxin to bind to cells bearing the EGF receptor; the chimeric toxin DAB 389 -IL-2; and the chimeric toxin DAB 389 -EGF. In other preferred embodiments in which the ligand is IL-2 or a portion thereof, the chimeric toxin possesses at least one of: greater toxicity to IL-2 receptor-bearing cells than that exhibited by DAB 486 -IL-2, a lower K d for the IL-2 high affinity receptor than that of DAB 486 -IL-2, or a greater resistance to proteolytic degradation than that exhibited by DAB 486 -IL-2. In other preferred embodiments in which the ligand is EGF or a portion thereof, the chimeric toxin posseses at least one of: greater toxicity to EGF-receptor-bearing cells than that exhibited by DAB 486 EGF; a lower K d for the EGF receptor than that of DAB 486 EGF, greater resistance to the inhibition of its cytotoxicity by competetive inhibitors, e.g., EGF, than that of DAB 486 -EGF; the ability to inhibit protein synthesis in EGF receptor bearing cells to a given degree by a period of exposure that is shorter than the period of exposure required by DAB 486 EGF to inhibit protein synthesis to the same degree; or the ability to effect a more rapid onset of the inhibition of protein synthesis in EGF-receptor-bearing cells than that seen in DAB 486 EGF. The chimeric toxins of the invention are preferably encoded by fused genes which include regions encoding the protein fragments of the chimeric toxin, DNA sequences encoding the chimeric toxins of the invention, expression vectors encoding those DNA sequences, cells transformed with those expression vectors, and methods of producing the chimeric toxins including culturing cells transformed with expression vectors containing DNA encoding the chimeric toxins and isolating the chimeric toxins from the cells or their supernatants. Native diphtheria toxin, as used herein, means the 535 amino acid diphtheria toxin protein secreted by Corynebacterium diphtheriae. The sequence of an allele of the gene which encodes native diphtheria toxin can be found in Greenfield et al. (1983) Proc. Natl. Acad. Sci. USA 80:6853-6857, hereby incorporated by reference. Enzymatically active Fragment A, as used herein, means amino acid residues Gly 1 through Arg 193 of native DT, or an enzymatically active derivative or analog of the natural sequence. Cleavage domain 1 1 , as used herein, means the protease sensitive domain within the region spanning Cys 186 and Cys 201 of native DT. Fragment B, as used herein, means the region from Ser 194 through Ser 535 of native DT. The hydrophobic transmembrane region of Fragment B, as used herein, means the amino acid sequence bearing a structural similarity to the bilayer-spanning helices of integral membrane proteins and located approximately at or derived from amino acid residue 346 through amino acid residue 371 of native diphtheria toxin. Domain 1 2 , as used herein, means the region spanning Cys 461 and Cys 471 of native DT. The generalized eukaryotic binding site of Fragment B, as used herein, means a region within the C-terminal 50 amino acid residues of native DT responsible for binding DT to its native receptor on the surface of eukaryotic cells. The chimeric toxins of the inventions do not include the generalized eukaryotic binding site of Fragment B. Toxic or cytotoxic, as used herein, means capable of inhibiting protein synthesis in a cell, inhibiting cell growth or division, or killing a cell. DAB 486 consists of, in the following order, methionine, and amino acid residues 1-485 of native DT. DAB 389 consists of, in the following order, methionine, amino acid residues 1-386 of native DT, and amino acid residues 484-485 of native DT. DAB 486 -IL-2 is a fusion protein consisting of, in the following order, methionine, amino acid residues 1-485 of native DT, and amino acid residues 2-133 of IL-2. DAB 485 -IL-2 is identical except that it lacks the initial methionine residue. DAB 389 -IL-2 consists of DAB 389 fused to amino acid residues 2-133 of IL-2. DAB 389 EGF consists of DAB 389 fused to EGF. Receptor means the site to which the cell-specific polypeptide ligand (described in (d) above) binds. Chimeric toxins of the invention display one or more of the following advantages: greater toxicity than that of an analagous DAB 486 -containing toxin; a greater affinity for the receptor than that of an analagous DAB 486 -containing toxin; when expressed in the cytoplasm of E.coli, greater resistance to proteolytic degradation than that exhibited by an analagous DAB 486 -containing toxin; greater resistance to the inhibition of its cytotoxicity by competitive inhibitors, e.g., the polypeptide of (d) above, than that exhibited by an analagous DAB 486 -containing toxin; the ability to inhibit protein synthesis in target cells to a given degree by a period of exposure that is shorter than the period of exposure required by an analogous DAB 486 -containing-toxin to inhibit protein synthesis to the same degree; or the ability to effect a more rapid onset of the inhibition of protein synthesis than that seen in an analagous DAB 486 -containing-toxin. Aberrant expression of the epidermal growth factor receptor is a characteristic of several malignancies including those of the breast, bladder, prostate, lung and neuroglia. Chimeric toxins of the invention allow therapeutic targeting the cytotoxic action of diptheria toxin to EGF receptor positive tumor cells. In these chimeric toxins the sequences for the binding domain of diptheria toxin have been replaced by those for human EGF. These chimeric toxins inhibit protein synthesis by the same mechanism as diptheria toxin and are specifically cytotoxic for human tumor cells which express elevated levels of EGF receptors. The uptake of these chimeric toxins occur with kinetics which permit use of this molecule as a powerful therapeutic agent for treatment of malignancies characterized by EGF receptor expression. Other features and advantages of the invention will be apparent from the following description of the preferred embodiments and from the claims. DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings will first be briefly described. Drawings FIG. 1 is a diagram of the DT molecule and of various fusion proteins. FIG. 2 is a depiction of the construction of the plasmids of a preferred embodiment. FIG. 3 is a restriction map of DNA sequences encoding various chimeric toxins. FIG. 4 is a graph of the effects of varying doses of chimeric toxins on cultured cells. FIG. 5 is a graph of the ability of chimeric toxins to competitively displace 125 I!-labeled IL-2 from the high affinity IL-2 receptor. FIG. 6 is the sequence of a synthetic EGF gene. FIG. 7 is a diagramatic representation of DAB 486 EGF and DAB 389 EGF. FIG. 8 is a graph showing the effect of EGF on DAB 486 EGF cytotoxicity. FIG. 9 is a graph showing the effect of EGF on DAB 389 EGF cytotoxicity. FIG. 10 is a graph showing the effect of EGF and DAB 389 EGF on the EGF binding capacity of A431 cells. FIG. 11 is a graph showing the ability of EGF or DAB 389 EGF to displace 125 I! EGF from EGF receptors. FIG. 12 is a graph of the effect of length of exposure to DAB 486 EGF on the inhibition of protein synthesis. FIG. 13 is a graph of the effect of length of exposure to DAB 389 EGF on the inhibition of protein synthesis. FIG. 14 is a graph of the kinetics of the inhibition of protein synthesis on cells incubated with DAB 486 EGF or DAB 389 EGF. STRUCTURE AND SYNTHESIS OF CHIMERIC TOXIN DAB 486 -IL-2 DAB 486 -IL-2 is a chimeric toxin consisting of Met followed by amino acid residues 1 through 485 of mature DT fused to amino acid residues 2 through 133 of IL-2 . The DT portion of the chimeric toxin DAB 486 -IL-2 includes all of DT fragment A and the portion of DT fragment B extending to residue 485 of mature native DT. Thus DAB 486 -IL-2 extends past the disulfide bridge linking Cys461 with Cys471. See FIG. 1a for the structure of DT. (The nomenclature adopted for IL-2-toxin is DAB 486-IL- 2, where D indicates diphtheria toxin, A and B indicate wild type sequences for these fragments, and IL-2 indicates human interleukin-2 sequences. Mutant alleles are indicated by a number in parentheses following DAB. The numerical subscript indicates the number of DT-related amino acids in the fusion protein. Since the deletion of the tox signal sequence and expression from the trc promoter results in the addition of a methionine residue to the N-terminus, the numbering of DAB-IL-2 fusion toxins is +1 out of phase with that of native diphtheria toxin.) pDW24, which carries DAB 486 -IL-2 was constructed as follows. pUC18 (New England BioLabs) was digested with PstI and BglI and the PstI-BglI fragment carrying the E.coli origin of replication, the polylinker region, and the 3' portion of the β-lacatamase gene (amp r ) was recovered. Plasmid pKK-233-2 (Pharmacia) was digested with PstI and BglI and the PstI-BglI fragment carrying, two transcription terminators and the 5' portion of the β-lactamase gene was recovered. pDW22 was constructed by ligating these two recovered fragments together. pDW23 was constructed by isolating a BamHI-SalI fragment encoding human IL-2 from plasmid pDW15 (Williams et al. (1988) Nucleic Acids Res. 16:10453-10467) and ligating it to BamHI/SalI digested pDW22 (described above). pDW24 was constructed as follows. A BamHI-NcoI fragment carrying the trc promoter and translational initiation codon (ATG) was isolated from plasmid pKK233-2 (Pharmacia). The DNA sequence encoding amino acid residues 1 through 485 of DT was obtained by digesting pABC508 (Williams et al. (1987) Protein Engineering 1:493-498) with SphI and HaeII and recovering the HaeII-SphI fragment containing the sequence encoding amino acid residues 1 through 485 of DT. A NcoI/HaeII linker (5'CCATGGGCGC 3') was ligated to the HaeII-SphI fragment and that contruction was then ligated to the previously isolated BamHI-NcoI fragment carrying the trc promoter. This results in a Bam HI-SphI fragment bearing, in the following order, the trc promoter, the NcoI site (which supplies the ATG initiator codon for Met), and the sequence encoding residues 1 through 485 of native DT. This fragment was inserted into pDW23 that had been digested with Bam HI and SphI. The resulting plasmid was desigated pDW24. The fusion protein (DAB 486 -Il-2) encoded by pDW24 is expressed from the trc promoter and consists of Met followed by amino acids 1 through 485 of mature DT fused to amino acids 2 through 133 of human IL-2. The sequence of DT is given in Greenfield et al. (1983) supra. The sequence encoding IL-2 was synthesized on an Applied Biosystems DNA-Synthesizer, as described in Williams et al. (1988) Nucleic Acids Res. 16:10453-10467, hereby incorporated by reference. The sequence of IL-2 is found in Williams et al. (1988) Nucleic Acids Res. 16:10453-10467. Fusion of the sequence encoding mature DT to ATG using an oligonucleotide linker is described in Bishai et al. (1987) J. Bact. 169:5140-5151, hereby incorporated by reference. pDW24 is shown in FIG. 2. The insert corresponding to DAB 486 -IL-2 is shown as a heavy line. In FIG. 2 filled circles indicate NcoI sites, open circles indicate NsiI sites, open diamonds indicate ClaI sites, filled squares indicate HpaII sites, open squares indicate SphI sites, and filled triangles indicate SalI sites. Oligonucleotides and nucleic acids were manipulated as follows. Oligonucleotides were synthesized using cyanoethyl phosphoramidite chemistry on an Applied Biosystems 380A DNA synthesizer (Applied Biosystems Inc., Foster City, Calif.). Following synthesis, oligonucleotides were purified by chromatography on Oligonucleotide Purification Cartridges (Applied Biosystems Inc., Foster City, Calif.) as directed by the manufacturer. Purified oligonucleotides were resuspended in TE buffer (10 mM Tris base, 1 mM EDTA, pH 8.0). To anneal complementary strands, equimolar concentrations of each strand were mixed in the presence of 100 mM NaCl, heated to 90° C. for 10 min, and allowed to cool slowly to room temperature. Plasmid DNA was purified by the alkaline lysis/cesium chloride gradient method of Ausebel et al. (1989) Current Protocols in Molecular Biology, John Wiley & Sons, N.Y. DNA was digested with restriction endonucleases as recommended by the manufacturer (New England Biolabs, Beverly, Mass. and Bethesda Research Laboratories, Gaithersburg, Md.). Restriction fragments for plasmid construction were extracted from agarose-TBE gels, ligated together (with or without oligonucleotide linkers) and used to transform E. coli using standard methods. Ausebel et al (1989) supra and Maniatis et al. (1982), Molecular Cloning Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. Plasmid DNA sequencing was performed according to the dideoxy chain termination method of Sanger et al. (1987) Proc. Nat'l Acad. Sci USA 74:5463-5467, as modified by Kraft et al. (1988) Bio Techniques 6:544-547, using Sequenase (United States Biochemicals, Cleveland, Ohio). Structure of Improved Diphtheria-IL-2 Chimeric Toxins Expression and purification of chimeric toxins was as follows. All DT-related IL-2 fusion proteins used herein were expressed in the cytoplasm of E. coli strain JM101 from the trc promoter, Amann et al. (1985), Gene 40:183-190, hereby incorporated by reference. Recombinant E. coli were grown in M9 minimal medium (Maniatis et al. (1982) supra) supplemented with 10 mg/ml casamino acids (Difco, Detroit, Mich.), 50 μg/ml ampicillin, and 0.5 ng/ml thymine in 10 liter volumes in a Microgen Fermentor (New Brunswick Scienctific, Edison, N.J.). Bacterial cultures were grown at 30° C., and sparged with air at 5 L/min. When the absorbance (A 590 nm) of the culture reached 0.3, expression of chimeric tox gene was induced by the addition of isopropyl-β-D- thiogalactopyranoside. Two hours after induction, bacteria were harvested by centrifugation, resuspended in buffer #101 (50 mM KH 2 P0 4 , 10 mM EDTA, 750 mM NaCl, 0.1% Tween 20, pH 8.0), and lysed by sonication (Branson Sonifier). Whole cells and debris were removed by centrifugation at 27,000×g, and the clarified extract was then filter sterilized and applied to an anti-diphtheria toxin immunoaffinity column. Bound proteins were eluted with 4 M guanidine hydrochloride, reduced by the addition of β-mercaptoethanol to 1% and then sized by high pressure liquid chromatography on a 7.5×600 mm G4000PW column (TosoHass). Prior to use, fusion toxins were exhaustively dialysed against HEPES buffered Hank's balanced salt solution (Gibco), pH 7.4. Purified diphtheria toxin was purchased from List Biological Laboratories (Campbell, Calif.). For the production of the non-toxic CRM1001, C7(βtox-1001) was grown in 100 ml volumes of C-Y medium (Rappuoli et al. (1983) J. Bact. 153:1201-1210) in 2-liter Erlenmeyer flasks at 35° C. for 20 hrs with shaking (240 rpm). Bacteria were removed by centrifugation at 20,000×g for 15 min. CRM1001 was precipitated from the culture medium by the addition of NH 4 SO 4 to 70% saturation, and collected by centrifugation. Following dialysis against 10 mM phosphate buffer, pH 7.2, CRM1001 was purified by ion exchange chromatography on DE-52 cellulose as previously described by Pappenheimer et al. (1972), Immunochem. 9:891-906. The concentration of all purified proteins was determined by using Pierce Protein Assay reagent (Pierce Chemical Co., Rockford, Ill.). DAB(1001) 486 -IL-2 is a chimeric toxin identical to DAB 486 -IL-2 except for the disruption of the disulfide bridge between Cys462 and Cys472 in DAB(1001) 486 -IL-2. DAB(1001) 486 -IL-2 was constructed by replacing the 587 basepair (bp) ClaI-SphI restriction fragment which encodes most of fragment B of DT) of plasmid pDW24 (which carries DAB 486-IL- 2 ) with the analogous fragment from DNA encoding the TOX-1001 mutant allele of DT. TOX-1001 encodes non-toxic diphtheria toxin-related protein CRM1001 and has been shown to result from a single point mutation which changes Cys471 to Tyr471, Rappuoli et al. (1986) In Protein Carbohydrate Interactions in Biological Systems, Academic Press, Inc., London, pp. 295-296, hereby incorporated by reference. FIG. 3 depicts the restriction maps of DNA encoding DAB 486 -IL-2 and the corresponding fusion protein encoded by DAB 486 -IL-2 . (In FIG. 3 stippled boxes between the NsiI and HpaII restriction endonuclease sites designate the diphtheria toxin fragment B-related sequences which encode the membrane associating domains. The amphipathic domain is encoded between the NsiI and ClaI sites, and the putative membrane spanning domains are encoded between the ClaI and HpaII sites. Hatched boxes indicate the relative position of internal in-frame deletion mutations.) The construction of pDW26, which encodes the chimeric toxin with the Cys472 to Tyr472 mutation, is shown in FIG. 2. Following ligation and transformation, the DNA sequence of the tox-1001 portion of the gene fusion DAB (1001) 486 -IL-2 was determined in order to insure that the Cys471 to Tyr471 mutation was recloned. E. coli (pDW26), was grown in M9 minimal media, cells were harvested, lysed and the fusion toxin, designated DAB(1001) 486 -IL-2, was purified by immunoaffinity chromatography and HPLC. The dose response capacity of DAB 486 -IL-2, CRM1001, and DAB(1001) 486 -IL-2 to block 14 C!-leucine incorporation by high affinity IL-2 receptor bearing HUT 102/6TG cells was determined. As anticipated, DAB 486-IL- 2 was highly toxic for these cells (IC 50 =4×10 -10 M); whereas, CRM1001 was found to be non-toxic. In marked contrast to CRM1001, however, the fusion toxin which carries the Cys472 to Tyr472 mutation, DAB(1001) 486 -IL-2 , was found to be as toxic for HUT 102/6TG cells as the wild type DAB 486 -IL-2. These results demonstrate that the fragment B disulfide bond is not required for biological activity of the fusion toxin. HUT 102/6TG cytotoxicity assays were performed as follows. Cultured HUT 102/6TG cells were maintained in RPMI 1640 medium (Gibco, Grand Island, N.Y.) supplemented with 10% fetal bovine serum (Cellect, GIBCO), 2 mM glutamine, and penicillin and streptomycin to 50 IU and 50 μg/ml, respectively. For cytotoxicity assays, cells were seeded in 96-well V-bottomed plates (Linbro-Flow Laboratories, McLean, Va.) at a concentration of 5×10 4 per well in complete medium. Toxins, or toxin-related materials, were added to varying concentrations (10 -12 M to 10-6M) and the cultures were incubated for 18 hrs at 37° C. in a 5% CO 2 atmosphere. Following incubation, the plates were centrifuged for 5 min. at 170×g and the medium removed and replaced with 200 μl leucine-free medium (MEM, Gibco) containing 1.0 μCi/ml 14 C!-leucine (New England Nuclear, Boston, Mass.). After an additional 90 min. at 37° C., the plates were centrifuged for 5 min. at 170×g, the medium was removed and the cells were lysed by the addition of 4 M KOH. Protein was precipitated by the addition of 10% trichloroacetic acid and the insoluble material was then collected on glass fiber filters using a cell harvester (Skatron, Sterling, Va.). Filters were washed, dried, and counted according to standard methods. Cells cultured with medium alone served as the control. All assays were performed in quadruplicate. Since the disulfide bond between Cys462-Cys472 was not required for the cytotoxic action of DAB 486 -IL-2, it was of interest to determine what DT fragment B sequences were essential for the delivery of fragment A to the cytosol. Several in-frame deletion mutations were introduced into the fragment B encoding portion of the DAB 486 -IL-2 toxin gene, FIGS. 1b, 2, and 3. FIG. 1b shows the structure of DAB 486 -IL-2 and various mutants derived from DAB 486 -IL-2. In FIG. 1b a wide bar indicates the fusion protein, narrow connecting lines represent deletions, numbers above the bars are amino acid residue numbers in the DAB nomenclature, numbers below the bars correspond to the amino acid residue numbering of native DT, cross hatching indicated amphipathic regions, darkened areas correspond to the transmembrane region, IL-2-2-133 indicates amino acid residues 2-133 of IL-2 , Ala=alanine, Asn=asparagine, Asp=aspartic acid, Cys=cysteine, Gly=glycine, His=histidine, Ile=isoleucine, Met=methionine, Thr=threonine, Tyr=tyrosine, and Val=valine. The first mutant, DAB 389 -IL-2 was constructed by removing a 309 bp HpaII-SphI restriction fragment from pDW24 and replacing it with oligonucleotide linker 261/274 (Table 1) to generate plasmid pDW27 (FIG. 1). This linker restores fragment B sequences from Pro383 to Thr387, and allows for in-frame fusion to IL-2 sequences at this position. Thus, in DAB 389 -IL-2 the 97 amino acids between Thr387 and His485 have been deleted. TABLE 1__________________________________________________________________________Oligonucleotide linkers oligonucleotideconstruct identification number linker__________________________________________________________________________DAB.sub.389 -IL-2 274 5'-CG GGT CAC AAA ACG CAT G-3' 261 CCA GTG TTT TGC 1/2 HpaII 1/2 SphIDAB.sub.295 -IL-2 292 5'-C GAT GGT GTG CAT G-3' 293 TA CCA CAC 1/2 ClaI 1/2 SphIDAB(Δ205- 337 5'-TA AAT AT-3'289).sub.486 -IL-2 338 ACG TAT TTA TAG C 1/2 NsiI 1/2 ClaIDAB(Δ205- 337 5'-TA AAT AT-3'289).sub.486 -IL-2 338 ACG TAT TTA TAG C 1/2 NsiI 1/2 ClaI__________________________________________________________________________ In a similar fashion, a 191 amino acid in-frame deletion was constructed by removing a ClaI-SphI restriction fragment from pDW24 and replacing it with the 292/293 oligonucleotide linker (Table 1) to form plasmid pDW28 which encodes DAB 295 -IL-2. In this case, the in-frame deletion encompasses the putative membrane-spanning helices that have been predicted by Lambotte et al. (1980) J. Cell. Biol. 87:837-840, to play a role in the delivery of fragment A to the eukaryotic cell cytosol. Purified, DAB 389 -IL-2 and DAB 295 -IL-2 were found to have electrophoretic mobilities of 57 kDa and 47 kDa, respectively. The dose response analysis on HUT 102/6TG cells is shown in FIG. 4. In FIG. 4 DAB 486 -IL-2 is indicated by filled squares; DAB 389 -IL-2 is indicated by filled circles; DAB 295 -IL2 is indicated by open circles; DAB(Δ205-289) 486 -IL-2 (see below) is indicated by open squares; and DAB(Δ205-289) 389 -IL-2 (see below) is indicated by open triangles. DAB 486 -IL-2 and DAB 389 -IL-2 exhibited an IC 50 of approximately 4×10 -10 M and 1×10 -10 M, respectively. In marked contrast, the IC 50 of DAB 295 -IL-2 was approximately 1,000-fold lower (4×10 -7 M). These results suggest that fragment B sequences between Thr387 and His486 do not play a major role in the delivery of fragment A to the cytosol. Sequences between Ser292 and Thr387 on the other hand are essential for the efficient delivery of fragment A. Surprisingly, DAB 389 -IL-2 possessed much greater activity than did DAB 486 -IL-2. DAB 389 -IL-2, which lacks native DT residues 387 through 483, and which has increased toxic activity, leaves the hydrophobic transmembrane segment located approximately between native DT residues 346 and 371 intact. See Lambotte et al. (1980) J. Cell Biol. 87:837-840, hereby incorporated by reference, for a characterization of the transmembrane region. DAB 295 -IL-2, which removes native DT residues 291 through 481, and which has greatly reduced toxicity, removes the transmembrane region (346-371). In order to rule out the possibility that the reason for the low potency of DAB 295 -IL-2 for HUT 102/6TG cells was related to altered binding to the high affinity IL-2 receptor, we have conducted a series of competitive displacement experiments using 125 I!-rIL-2 . FIG. 5 shows the competitive displacement of 125 I!-labeled IL-2 from the high affinity IL-2 receptor by unlabeled rIL-2 depicted by filled circles; DAB 486 -IL-2 depicted by open triangles; DAB 389 -IL-2 depicted by closed squares; DAB 295 -IL-2 depicted by closed triangles; DAB(Δ205-289) 486 -IL-2 (see below) depicted by open circles; and DAB(Δ205-289) 389 -IL-2 (see below) depicted by open squares. The concentration of 125 !-IL-2 used was 10 pM and the specific activity was approximately 0.7 μCi/pmol. As shown in Table 2, both DAB 389 -IL-2 and DAB 295 -IL-2 were found to have an apparent K d that is approximately 3-times lower than that of DAB 486 -IL-2 (K d =8×10 -9 M vs. K d =2.5×10 -8 M). It is particularly significant that competitive displacement experiments showed that both DAB 389 -IL-2 and DAB 295 -IL-2 bind more avidly to the high affinity IL-2 receptor than does DAB 486 -IL-2 (Kd=8×10 -9 and 8.4×10 -9 M vs. Kd=2.5×10 -8 M). These results provide evidence that fusion of IL-2 sequences to toxophores of smaller mass may serve to position the IL-2 binding domain for more favorable receptor interaction. It is of interest to note that while DAB 295 -IL-2 binds more avidly to the high affinity IL-2 receptor than DAB 486 -IL-2, its cytotoxic activity is at least 1,000-fold lower (FIG. 4). These results indicated that avid binding to the target receptor is not in itself sufficient for the biologic activity of the DT-related IL-2 fusion toxins, and that fragment B sequences between Ser292 and Thr387 are essential for a post-receptor binding event in the intoxication process. TABLE 2______________________________________Relative ability of rIL-2 and DAB-IL-2 related fusionproteins to displace .sup.125 I!--rIL-2 from highaffinity IL-2 receptors on HUT 102/6TG cellsunlableled ligand apparent K.sub.d K.sub.d DAB-IL-2/rIL-2______________________________________rIL-2 .sup. 1.7 × 10.sup.-10 --DAB.sub.486 -IL-2 2.5 × 10.sup.8 147DAB.sub.389 -IL-2 8.0 × 10.sup.9 47DAB.sub.295 -IL-2 8.4 × 10.sup.9 49DAB(Δ205-289).sub.486 -IL-2 1.0 × 10.sup.-7 588DAB(Δ205-289).sub.389 -IL-2 2.9 × 10.sup.-8 170______________________________________ Competitive displacement of 125 I!-rIL-2 by rIL-2 and DAB-IL-2 fusion toxins was determined as follows. The radiolabeled IL-2 binding assay was performed essentially as described by Wang et al. (1987) J. Exp. Med. 166:1055-1069. Cells were harvested and washed with cell culture medium. HUT 102/6TG cells were resuspended to 5×10 6 per ml and incubated with 125 I!-rIL-2 (0.7 μCi/pmol) in the presence or absence of increasing concentrations of unlabeled rIL-2 or the DAB-IL-2 fusion toxins for 30 min. at 37° C. under 5% CO 2 . The reaction was then overlayed on a mixture of 80% 550 fluid (Accumetric Inc., Elizabethtown, Ky.): 20% parafin oil (d=1.03 g/ml) and microcentrifuged. The aqueous phase and the pellet of each sample, representing free and bound ligand, respectively, was then counted in a Nuclear Chicago gamma counter. Apparent dissociation constants, K d , were determined from the concentrations of unlabeled ligand required to displace 50% of radiolabeled rIL-2 binding to receptors. In order to test the hypothesis that an amphipathic region (amino acids 210-252 in DAB 486-IL- 2) plays a role in the intoxication process, in-frame deletions of the 85 amino acid encoding region from NsiI to ClaI of both pDW24 and pDW27 to form pDW30 (containing DAB(Δ205-289) 486 -IL-2) and pDW31 (containing DAB(Δ205-289) 389 -IL-2 ), respectively (FIGS. 2 and 3; Table 1) were constructed. Following ligation and transformation, the DAB-IL-2 related fusion proteins were expressed and purified, as described above. As shown in FIG. 4, the deletion of fragment B sequences which include the amphipathic region result in a marked loss of cytotoxic activity against high affinity IL-2 receptor positive cells in vitro. It is of interest to note that DAB (Δ205-289) 389 - IL-2 was found to displace radiolabeled IL-2 from the high affinity receptor almost as well as DAB 486 -IL-2; whereas, DAB(Δ205-289) 486 -IL-2 was found to bind 4-fold less avidly to the receptor (FIG. 5). Increased Resistance to Proteolytic Degradation The chimeric toxin encoded by DAB 389 -IL-2 is more resistant to proteolytic degradation than is the chimeric toxin encoded by DAB 486 -IL-2. When purified, as described above, and analysed on SDS-polyacrylamide gels, the DAB 389 -IL-2 hybrid toxin is accompanied by very few degradation products (as evidenced by the relative absence of bands of smaller size than that of the intact chimeric toxin). Purified DAB 486 -IL-2 on the other hand is accompanied by numerous dark bands of lower molecular weight than the intact chimeric toxin. These lower molecular weight bands react with anti-DAB 486 -IL-2 antibodies, supporting the conclusion that they are degradation products. Sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) was performed according to the method of Laemmli (1970) Nature 227:680-685 using 12% gels and a Mini-Protein II gel apparatus (BioRad). Proteins were fixed in 12.5% trichloroacetic acid for 5 min and stained with Coomassie brilliant blue according to the Diezal procedure, Diezal et al. (1972) Anal. Biochem. 48:617-624. Construction of Fusion Genes Encoding DT-EGF Chimeric Toxins DAB 486 EGF and DAB 389 EGF can be constructed in a manner analogous to that in which DAB 486 -IL-2 and DAB 389 -IL-2 were constructed, by methods known to those skilled in the art. To construct a plasmid encoding DAB 486 fused to EGF, plasmid pDW24 (which encodes DAB 486 fused to IL-2) is digested with SphI and HindIII to remove the IL-2 coding sequence. The resulting pDW24 SphI-HindIII fragment containing the sequence encoding DT residues 1-485 is ligated to a synthetic SphI-HindIII fragment encoding EGF to yield a plasmid encoding DAB 486 fused to EGF. The EGF fragment, shown in FIG. 6, was synthesized, as described, using preferred codons for expression in E.coli (see Grosjean et al. (1982) Gene 18:199-209, hearby incorporated by reference). The synthetic fragment includes appropriate linkers at the 5' and 3' ends for insertion into the plasmid and for in-frame fusion to the DT coding sequence. To construct a plasmid encoding DAB 389 fused to EGF a similar protocol can be followed, except that pDW27 (which encodes DAB 389 fused to IL-2) is used in place of pDW24. The IL-2 encoding DNA is removed from pDW27 by digestion with SphI and HindIII and EGF encoding DNA is inserted in its place, resulting in a DAB 389 fused in frame to EGF. The same synthetic EGF fragment used in the construction of the DAB 489 EGF fusion (FIG. 6) can be used. Those skilled in the art will realize that the protocols given above are not the only way of making the chimeric toxins of the invention. Refinements include changes in pDW24, pDW27, and plasmids derived therefrom directed toward compliance with the Good Manufacturing Practises of the Food and Drug Administration, e.g., the inclusion of the lacI q gene (Amersham) and the replacement of the ampicillin resistance gene (amp r ) with the gene for neomycin/kanamycin resistance from Tn5 (Pharmacia) in the plasmids that are used for expression of the chimeric toxins of the invention. These alterations can be performed without undue experimentation by one skilled in the art. The Biological Activity of DT-EGF Chimeric Toxins DAB 486 EGF and DAB 389 EGF are the products of fusion genes in which the receptor binding domain of DT has been removed and replaced with DNA encoding human EGF. As shown in FIG. 7, the resulting proteins contain the enzymatically active fragment A of DT and the lipid associating domains of fragment B of DT required for translocation of fragment A into the cytosol. DAB 389 EGF differs from DAB 486 EGF by the deletion of the 97 amino acids immediately 5' to amino acid residue 484 of DT. The EGF portion of both DAB 486 EGF and DAB 389 EGF governs receptor binding. Thus, these molecules have the potential to specifically target the cytotoxicity of DT to tumor cells characterized by EGF receptor expression. DT-EGF Chimeric Toxins Are Toxic to EGF-Receptor-Bearing Cells. The cytotoxicity of DAB 486 EGF for a panel of human cell lines was assessed and compared to A431 cells (ATCC CRL 1555), a human epidermoid carcinoma cell line with a high number of EGF receptors. The results are shown in Table 3. Included in the study were human tumor cell lines which have been reported to express high numbers of EGF receptors (e.g., BT-20, HeLa, LNCaP and U-87 MG) as well as human tumor cell lines (e.g., C91/PL, BeWo and A375) and normal tissue cell lines (e.g., WI-38, Hs 67 and HEPM) expressing few or no EGF receptors. Cytotoxicity was evaluated as follows. Cells were plated in triplicate wells of 96 well plates with DAB 486 EGF in assay medium appropriate to the cell type (see Table 3). DAB 486 EGF concentrations were between 10 -15 and 10 -7 M. Following a 20-hour incubation, cells were labeled with 14 C! leucine, trypsinized, harvested onto glass fiber filter mats and counted to determine the percent of control incorporation. Cell lines exhibiting an IC 50 for DAB 486 EGF of less than 0.5 nM were considered sensitive. TABLE 3______________________________________The effect of a DT-EGF chimeric toxin on various cell lines______________________________________Tumor Cell linesCell Line Tissue/Type Sensitivity______________________________________A431 vulval epidermoid carcinoma +A549 lung carcinoma +KB oral epidermoid carcinoma +BT-20 breast adenocarcinoma +HeLa S3 cervical carcinoma +T47D breast ductal carcinoma +LNCaP.FG prostate carcinoma +HOS osteosarcoma +U-87 MG glioblastoma/astrocytoma +C91/PL HTLV-1 transformed T cell -BeWo choriocarcinoma -A375 malignant melanoma -MCF-7 breast adenocarcinoma -SNU-C2B cecum carcinoma -______________________________________Normal Cell LinesCell Line Tissue Sensitivity______________________________________WI-38 diploid lung fibroblast -Hs 67 thymus -CCD-18Co colon fibroblast -HISM smooth muscle, jejunum -FH74s Int fetal small intestine -HEPM embryonic palatal - mesenchyme______________________________________ Growth conditions and passage schedules used were those defined by ATCC (except as noted below). Culture media were as follows: A431 (ATCC CRL1555), DMEM+10% FCS; A549 (ATCC CCL185) Ham's F12+10% FCS; KB (ATCC CCL17), DMEM+NEAA+10% FCS; BT-20 (ATCC HTB19), MEM+10% FCS; HeLa S3 (ATCC CCL2.2), Ham's F12+10% FCS; T47D (ATCC HTB133), RPMI 1640+10% FCS; LNCaP.FG (ATCC CRL1740), RPMI 1640+10% FCS; HOS (ATCC CRL1543), MEM+10% FCS; U-87 MG (ATCC HTB14), MEM+10% FCS; C91/PL (from Robert Swartz, NEMC, Boston, Mass., see Bacha et al. (1988) J. Exp. Med. 167:612 for growth conditions), RPMl 1640+15% FCS; BeWo (ATTC CCL98), Ham's F12+15% FCS; A375 (ATCC CRL 1619), DMEM+10% FCS; MCF-7 (ATCC TB22) MEM+10% FCS; SNU-C2B (ATCC CCL250) RPMl 1640+10% FCS; WI-38 (ATCC CCL75), Eagle's Basal+10% FCS; Hs 67 (ATCC HTB 163), DMEM+10% FCS; CCD-18Co (ATCC CRL 1459), MEM+10% FCS; HISM (ATCC CRL 1692), DMEM+10% FCS; FHs74Int (ATCC CCL241), DMEM+10% FCS; HEPM (ATCC CRL 1486), MEM+10% FCS. DMEM=Dulbecco's modified Eagles Medium; MEM=Minimum Essential Medium; NEAA=Non-Essential Amino Acids; FCS=Fetal Calf Serum; ATCC=American Type Culture Collection. To demonstrate that the cytotoxic action of DAB 486 EGF and DAB 389 EGF are mediated selectively by the EGF receptor, A431 cells were plated in triplicate wells of 96 well plates with DAB 486 EGF (FIG. 8) or DAB 389 EGF (FIG. 9) in the presence of the specific competitor of the EGF receptor, human EGF (Upstate Biotechnologies, Inc.) (10 -7 M), in assay medium (DMEM+10% FCS). In FIG. 8 solid squares indicate DAB 486 EGF and solid triangles indicate DAB 486 EGF+EGF. In FIG.9 solid squares indicate DAB 389 EGF and solid triangles indicate DAB 389 EGF+EGF. Following a 20-hour incubation at 37° C., cells were labeled with 14 C! leucine, trypsinized, harvested onto glass fiber filter mats and counted to determine the percent of control incorporation. The results show that, in the absence of EGF, DAB 486 EGF and DAB 389 EGF inhibit protein synthesis with an IC 50 of 3×10 -12 M and 3×10 -13 M, respectively. EGF almost completely abolishes this activity. Likewise, anti-EGF (Biomedical Technologies, Inc.) and anti-EGF receptor (Upstate Biotechnologies, Inc.) also abolish the cytotoxicity of DAB 486 EGF and DAB 389 EGF while the nonspecific competitors, transferrin (Sigma) anti-transferrin (Dako), and anti-transferrin receptor (Dako), have no effect. These results demonstrate that DAB 486 EGF and DAB 389 EGF are potent and specific cytotoxic agents. Note that DAB 389 EGF is approximately 10 times more potent than DAB 486 EGF. DAB 389 EGF, like EGF, induces down regulation of the EGF receptor, providing further evidence for the EGF receptor-specific nature of DT-EGF chimeric toxins. Binding and internalization of EGF induces down regulation of the EGF receptor which can be detected as a decrease in 125 I!EGF binding capacity (Krupp et al. (1982) J. Biol. Chem. 257:11489). The ability of DAB 389 EGF to induce EGF receptor internalization and subsequent down regulation was evaluated and compared to that induced by native EGF. The results are shown in FIG. 10. In FIG. 10 open squares indicate EGF and closed diamonds indicate DAB 389 EGF. A431 cells in triplicate wells of 24 well plates were preincubated with EGF or DAB 389 EGF (10 -8 M) for the indicated times in DMEM+0.1% BSA (bovine serum albumin) at 37° C. The cells were then placed on ice and acid stripped (with 0.2 M acetic acid, 0.5 M NaCl) to remove bound, but not internalized, EGF or DAB 389 EGF. EGF binding capacity was measured by incubating the cells, on ice, with 125 I !EGF. Following a 90-minute incubation the cells were washed, solubilized, and counted. An EGF receptor-dependent interaction is also shown by the fact that DAB 389 EGF, like EGF, displaces 125 I!EGF from the EGF receptor, as shown in FIG. 11. In FIG. 11 open squares indicate EGF and solid diamonds indicate DAB 389 EGF. Results in FIG. 11 are expressed as a percent of control (no competition) cpm. The ability of DAB 389 EGF to displace high affinity 125 I!EGF binding to A431 cells was evaluated as follows. A431 cells, plated in triplicate wells of 24 well plates, were preincubated in binding media (phosphate buffered saline pH 7.2+0.1% BSA+15 mM sodium azide+50 mM 2-deoxyglucose) for 1 hour at 37° C. and then incubated with 125 I!EGF in binding media in the presence of DAB 389 EGF or EGF. Following incubation, the cells were washed, solubilized and counted. The results are summarized in Table 4. In Table 4 EC 50 is the concentration resulting in displacement of 50% of the 125 I!EGF. TABLE 4______________________________________Displacement of .sup.125 I! EGF Binding by EGF and DAB.sub.389 EGF fold over fold overCompetition EC.sub.50 .sup.125 I! EGF EGF______________________________________EGF 1.0 × 10.sup.-8 M 20 --DAB.sub.389 EGF 4.5 × 10.sup.-7 M 900 45______________________________________ Cytotoxicity of DT-EGF Chimeric Toxins is DT Dependent. Upon binding to its receptor, the cellular uptake of native DT occurs by endocytosis of clathrin coated vesicles (Middlebrook et al. (1978) J. Biol. Chem. 253:7325). DT is then found in endosomes where the low pH induces a conformational change facilitating the translocation of the enzymatic fragment A portion of DT into the cytosol. To determine if the cytotoxicity of DAB 486 EGF and DAB 389 EGF is also dependent upon the same pathway, A431 cells were plated in sextuplicate wells of 96 well plates containing DAB 486 EGF, DAB 389 EGF or DMEM+10% FCS in the absence or presence of chloroquine (10 -5 M) (Sigma). Chloroquine is a lysosomotropic compound which prevents acidification of endosomes (Kim et al. (1965) J. Bacteriol. 90:1552). Following a 20-hour incubation at 37° C., the cells were labeled with 3 H! leucine, trypsinized, harvested onto glass fiber filter mats and counted. The results are shown in Table 5, expressed as the percent of control (no DAB 486 EGF or DAB 389 EGF) incorporation and represent the mean of three experiments. The results show that chloroquine blocks the cytotoxicity of DT-EGF chimeric toxins. TABLE 5______________________________________Sensitivity of DAB-EGF Chimeric Toxin-Cytotoxicity toChloroquinePercent of Control Incorporation No Addition Chloroquine______________________________________DAB.sub.486 EGF Concentration0 100 8610.sup.-8 M 5 6010.sup.-9 M 25 96DAB.sub.389 EGF Concentration0 100 7310.sup.-11 M 4 6110.sup.-12 M 57 100______________________________________ Following translocation into the cytosol, fragment A catalyzes the cleavage of NAD and the covalent linkage of ADP-ribose to elongation factor 2 (EF-2) resulting in the inhibition of protein synthesis (Bacha et al. (1983) J. Biol. Chem. 258:1565). To evaluate the mechanism by which DAB 486 EGF inhibits protein synthesis, A431 cells were plated in triplicate wells of 24 well plates containing DT, DAB 486 EGF, or complete medium. Following a 20-hour incubation at 37° C., the cells were washed and incubated in lysis buffer (10 mM Tris, 10 mM NaCl, 3 mM Mg Cl 2 , 10 mM thymidine, 1 mM EGTA, 1% TRITON X-100) with 32 P!NAD in the presence of purified DT fragment A (Calbiochem). TCA precipitable extracts were collected on glass fiber filters and counted to quantitate the percent of control EF-2 available for ADP-ribosylation. The results of these experiments are shown in Table 6. DAB 486 EGF, like DT, reduced (in a dosage dependent manner) the amount of EF-2 available for ADP ribosylation. TABLE 6______________________________________ADP-Ribosylation of EF-2 by DAB.sub.486 EGF Percent of Control Level of EF-2 Available forToxin Concentration for ADP-ribosylation______________________________________DT 10.sup.-8 M <1 10.sup.-9 M 17DAB.sub.486 EGF 10.sup.-8 M 13 10.sup.-9 M 20______________________________________ DAB 389 EGF Is An Improved Chimeric Toxin. DAB 389 EGF is far more toxic than is DAB 486 EGF. As shown in FIGS. 8 and 9, DAB 389 EGF exhibits an IC 50 for the inhibition of protein synthesis in A431 cells approximately 10 times lower than that of DAB 486 EGF (DAB 389 EGF IC 50 =3×10 -13 M; DAB 486 EGF IC 50 =3×10 -12 M). The greater potency of DAB 389 EGF is also shown in experiments measuring the rapidity with which DAB 389 EGF and DAB 486 EGF kill A431 cells. FIGS. 12 and 12 show the exposure time (of A431 cells to DAB 486 EGF or DAB 389 EGF) required to induce maximal inhibition of protein synthesis. Cells were exposed to DAB 486 EGF (5×10 -9 M) (FIG. 12) or DAB 389 EGF (5×10 -9 M) (FIG. 13) for the indicated times and then washed of unbound DAB 486 EGF or DAB 389 EGF. Following an overnight incubation in complete media (DMEM+10% FCS), the cells were labeled with 14 C! leucine. The results show that near maximal inhibition of protein synthesis occurs following a 15-minute exposure to DAB 389 EGF while a greater than 75-minute exposure is required for DAB 486 EGF. The kinetics of protein synthesis inhibition in DAB 389 EGF or DAB 486 EGF treated A431 cells is shown in FIG. 14. To examine the kinetics of protein synthesis inhibition A431 cells were incubated with DAB 486 EGF (5×10 -9 ) or DAB 389 EGF (5×10 -9 M) in complete medium at 37° C. At the indicated times, DAB 486 EGF or DAB 389 EGF was removed and the cells were labeled with 14 C! leucine for 1 hour. The results indicate that there is a 50% reduction in protein synthesis following a 1-hour incubation with DAB 389 EGF while maximal inhibition occurs by 4 hours. Maximal inhibition of protein synthesis occurs more than 6 hours following incubation with DAB 486 EGF. Use The improved chimeric toxins of the invention are administered to a mammal, e.g., a human, suffering from a medical disorder, e.g., cancer, or other conditions characterized by the presence of a class of unwanted cells to which a polypeptide ligand can selectively bind. The amount of protein administered will vary with the type of disease, extensiveness of the disease, and size of species of the mammal suffering from the disease. Generally, amounts will be in the range of those used for other cytotoxic agents used in the treatment of cancer, although in certain instances lower amounts will be needed because of the specificity and increased toxicity of the improved chimeric toxins. The improved chimeric toxins can be admnistered using any conventional method; e.g., via injection, or via a timed-release implant. In the case of MSH improved chimeric toxins, topical creams can be used to kill primary cancer cells, and injections or implants can be used to kill metastatic cells. The improved chimeric toxins can be combined with any non-toxic, pharmaceutically-acceptable carrier substance. Other Embodiments Other embodiments are within the following claims. For example, chimeric toxins have been constructed, by methods known to those skilled in the art, in which DAB 389 and DAB 486 have been fused to interleukin 4 (IL-4). DAB 389 -IL-4 is about 10 times more cytotoxic than is DAB 486 -IL-4. DAB 389 has also been fused to interleukin 6. DAB 486 and DAB 389 have also been fused to human chorionic gonadotropin. The improved chimeric toxins of the invention include portions of DT fused to any cell-specific polypeptide ligand which has a binding domain specific for the particular class of cells which are to be intoxicated. Polypeptide hormones are useful such ligands. Chimeric toxins, e.g., those made using the binding domain of α or β MSH, can selectively bind to melanocytes, allowing the construction of improved DT-MSH chimeric toxins useful in the treatment of melanoma. Other specific-binding ligands which can be used include insulin, somatostatin, interleukins I and III, and granulocyte colony stimulating factor. Other useful polypeptide ligands having cell-specific binding domains are follicle stimulating hormone (specific for ovarian cells), luteinizing hormone (specific for ovarian cells), thyroid stimulating hormone (specific for thyroid cells), vasopressin (specific for uterine cells, as well as bladder and intestinal cells), prolactin (specific for breast cells), and growth hormone (specific for certain bone cells). Improved chimeric toxins using these ligands are useful in treating cancers or other diseases of the cell type to which there is specific binding. For a number of cell-specific ligands, the region within each such ligand in which the binding domain is located is now known. Furthermore, recent advances in solid phase polypeptide synthesis enable those skilled in this technology to determine the binding domain of practically any such ligand, by synthesizing various fragments of the ligand and testing them for the ability to bind to the class of cells to be labeled. Thus, the chimeric toxins of the invention need not include an entire ligand, but rather may include only a fragment of a ligand which exhibits the desired cell-binding capacity. Likewise, analogs of the ligand or its cell-binding region having minor sequence variations may be synthesized, tested for their ability to bind to cells, and incorporated into the hybrid molecules of the invention. Other potential ligands include monoclonal antibodies or antigen-binding, single-chain analogs of monoclonal antibodies, where the antigen is a receptor or other moiety expressed on the surface of the target cell membrane.	A chimeric toxin comprising protein fragments joined together by peptide bonds, the chimeric toxin comprising, in sequential order, beginning at the amino terminal end of the chimeric toxin, (a) the enzymatically active Fragment A of diphtheria toxin, (b) a first fragment including the cleavage domain 1 1 adjacent the Fragment A of diphtheria toxin, (c) a second fragment comprising at least a portion of the hydrophobic transmembrane region of Fragment B of diphtheria toxin, the second fragment having a deletion of at least 50 diphtheria toxin amino acid residues, the deletion being C-terminal to the portion of the transmembrane region, and the second fragment not including domain 1 2 , and (d) a third fragment comprising a portion of a cell-specific polypeptide ligand, the portion including at least a portion of the binding domain of the polypeptide ligand, the portion of the binding domain being effective to cause the chimeric toxin to bind selectively to a predetermined class of cells to be attacked by the enzymatically active Fragment A.	2
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to fire log devices and more specifically it relates to a log system that is easy to light which burns longer and cleaner than conventional logs. [0003] 2. Description of the Prior Art [0004] Logs have been in use for years. A conventional log is simply comprised of a piece of wood from various types of trees. Modern logs are comprised of particulate wood material bonded together into a cylindrical structure that are commonly wrapped in a flammable wrapping to initiate the fire. [0005] Conventional log devices are difficult to ignite by conventional means and often times require the user to apply a flammable chemical which can be dangerous to ignite and cause significant pollution. Another problem with convention log devices is that they can be extremely messy to utilize with portions of the log such as the bark falling from the log onto the floor of a user's home. Another problem with conventional log devices is that they need to be replaced after a relatively short period of time with a fresh log. [0006] While these devices may be suitable for the particular purpose to which they address, they are not as suitable for providing a log system that is easy to light which burns longer and cleaner than conventional logs. Conventional logs are difficult to light and emit undesirable pollutants. [0007] In these respects, the log system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of providing a log system that is easy to light which burns longer and cleaner than conventional logs. SUMMARY OF THE INVENTION [0008] In view of the foregoing disadvantages inherent in the known types of log devices now present in the prior art, the present invention provides a new log system construction wherein the same can be utilized for providing a log system that is easy to light which burns longer and cleaner than conventional logs. [0009] The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new log system that has many of the advantages of the log devices mentioned heretofore and many novel features that result in a new log system which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art log devices, either alone or in any combination thereof. [0010] To attain this, the present invention generally comprises a housing comprised of a flammable material and a plurality of corn kernels contained within the housing which provide fuel to a fire. A copper member may be included within the housing for adding visual effects to the flame. A securing string may be attached about the housing for securing the housing in one piece. [0011] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and that will form the subject matter of the claims appended hereto. [0012] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. [0013] A primary object of the present invention is to provide a log system that will overcome the shortcomings of the prior art devices. [0014] A second object is to provide a log system for providing a log system that is easy to light which burns longer and cleaner than conventional logs. [0015] Another object is to provide a log system that does not utilize non-flammable materials in the construction. [0016] An additional object is to provide a log system that may be utilized as a portable seat. [0017] A further object is to provide a log system that provides a pleasant appearing flame. [0018] Another object is to provide a log system that may be easily transported. [0019] Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention. [0020] To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0021] Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: [0022] [0022]FIG. 1 is an upper perspective view of the present invention positioned within a grate. [0023] [0023]FIG. 2 is an upper perspective view of the present invention. [0024] [0024]FIG. 3 is a top view of the present invention. [0025] [0025]FIG. 4 is a side view of the present invention. [0026] [0026]FIG. 5 is an end view of the present invention. [0027] [0027]FIG. 6 is a cross sectional view taken along line 6 - 6 of FIG. 4. DESCRIPTION OF THE PREFERRED EMBODIMENT [0028] Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1 through 6 illustrate a log system 10 , which comprises a housing 20 comprised of a flammable material and a plurality of corn kernels 50 contained within the housing 20 which provide fuel to a fire. A copper member 60 may be included within the housing 20 for adding visual effects to the flame. A securing string 40 may be attached about the housing 20 for securing the housing 20 in one piece. The log system 10 may be positioned within an outdoor fire or upon a grate 12 . [0029] As shown in FIGS. 1 through 6 of the drawings, the housing 20 is comprised of a flammable material such as but not limited to wood. The housing 20 is a rigid structure defining an interior cavity for the storage of a plurality of corn kernels 50 , solid or crushed. The housing 20 preferably has a rectangular shape as best shown in FIG. 2 of the drawings. [0030] As shown in FIGS. 1 through 6 of the drawings, the housing 20 is preferably comprised of a pair of opposing end members 24 , a pair of side members 22 , a top member 26 and a lower member 28 . The pair of side members 22 are attached between the opposing end members 24 substantially parallel to one another as best illustrated in FIGS. 2 and 3 of the drawings. The top member 26 and the lower member 28 are attached between the opposing end members 24 and the side members 22 as best illustrated in FIGS. 2, 3 and 6 of the drawings. [0031] The opposing end members 24 , the pair of side members 22 , the top member 26 and the lower member 28 are preferably attached to one another utilizing a plurality of wood pegs 30 as further illustrated in FIGS. 1 through 6 of the drawings. The wood pegs 30 are inserted into apertures within the housing 20 thereby retaining the pair of side members 22 , the top member 26 and the lower member 28 in the desired location. A length of securing string 40 is preferably secured about the housing 20 to help maintain the desired structure of the housing 20 in the event one or more of the wood pegs 30 become loosened from the housing 20 . The securing string 40 is preferably comprised of a flammable material which are well-known in the art. [0032] As shown in FIG. 6 of the drawings, a plurality of corn kernels 50 are positioned within the interior cavity of the housing 20 for providing fuel to the fire. The corn kernels 50 may either be crushed or whole in structure. The corn kernels 50 may also be comprised of various corn varieties. [0033] As shown in FIG. 6 of the drawings, a copper member 60 may be positioned within the plurality of corn kernels 50 to provide an increased visual display during the burning of the plurality of corn kernels 50 . The copper member 60 may be comprised of various structures including tubular and solid. When the copper member 60 is heated by the burning of the surrounding corn kernels 50 a chemical reaction occurs that produces gases that are ignited into various colors that are emitted throughout the fire. The process continues until the copper member 60 is exhausted where after the chemical reactions will decrease along with the various colors emitted. [0034] As shown in FIGS. 1, 2 and 4 of the drawings, a plurality of vents 29 extend through the opposing side members 22 . The vents 29 are preferably positioned near an upper portion of the side members 22 . The vents 29 allow for increased burning of the corn kernels 50 within the housing 20 by allowing oxygen to enter and gases to escape from within. [0035] As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided. [0036] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed to be within the expertise of those skilled in the art, and all equivalent structural variations and relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. [0037] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. Index of Elements for Log System ENVIRONMENTAL ELEMENTS 10. Log System 11. 12. Grate 13. 14. 15. 16. 17. 18. 19. 20. Housing 21. 22. Side Members 23. 24. End Members 25. 26. Top Member 27. 28. Lower Member 29. Vents 30. Wood Pegs 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. Securing String 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. Corn Kernels 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. Copper Member 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79.	A log system for providing a log system that is easy to light which burns longer and cleaner than conventional logs. The log system includes a housing comprised of a flammable material and a plurality of corn kernels contained within the housing which provide fuel to a fire. A copper member may be included within the housing for adding visual effects to the flame. A securing string may be attached about the housing for securing the housing in one piece.	8
BACKGROUND OF THE INVENTION 1. Technical Field The present invention relates in general to railroad crossings for automobiles and, in particular, to a sealed, rodent-proof connection between the foundation and utility mast for a railroad gate flasher assembly at railroad crossings. 2. Description of the Related Art At railroad grade crossings, train warning systems employ gate flasher assemblies that lower gates to keep roadway traffic off of the rails when trains pass through the crossings. The gates are typically mounted on mast assemblies that are anchored to in-place foundations in the ground. Electrical cables or wiring typically pass underground from a nearby control box, through the foundation, and up into and through a junction box located on top of the foundation to provide power and signals to a gate swing mechanism, warning lights, and bell. In conventional gate flasher assembly designs, there is a clearance required between the bottom of the junction box and the top of the foundation to provide adequate space (e.g., a few inches) to properly level the junction box. The clearance is large enough for small rodents, such as mice, to enter and then climb up into the utility box. The rodents chew the insulation on the exposed electrical wiring and cause damage and electrical shorts in the signal lights and other electrical functions of the gate flasher assembly. To address this problem, railroad companies sometimes use expanding foam insulation to cover the space between the junction box and foundation. Although this practice is workable, an improved solution that permanently and completely seals the junction box and protects the wiring would be desirable to increase the reliability and durability of the gate flasher assembly. SUMMARY OF THE INVENTION Embodiments of a system, method, and apparatus for a railroad crossing gate flasher assembly having a sealed, rodent-proof connection between the foundation and utility mast are disclosed. The crossing gate flasher assembly is mounted on a foundation that is secured to the ground. Electrical cables pass from the foundation up into and through a junction box to power the gate swing mechanism, warning lights, and bell. A clearance between the bottom of the junction box and the foundation is sealed with a plate to prevent rodents from entering the junction box. The sealing plate seals and protects the wiring by preventing rodent infiltration. In one embodiment, the seal plate is mounted to the bolts that extend from the foundation. The seal plate is leveled after it is inserted onto the bolts. The junction box is lowered onto the seal plate and attached to the same bolts. Consequently, the junction box is level because the seal plate has already been leveled. The seal plate has a central opening and electrical conduit extending downward from the opening. The conduit extends below the seal plate and provides a connection point for the electrical conduit that protrudes from underground. When the junction box is mounted to the seal plate and the conduit is coupled to the seal plate, rodents cannot infiltrate the assembly. The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the present invention, taken in conjunction with the appended claims and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the features and advantages of the present invention are attained and can be understood in more detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof that are illustrated in the appended drawings. However, the drawings illustrate only some embodiments of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments. FIG. 1 is a schematic drawing of one embodiment of a gate flasher assembly at a railroad crossing and is constructed in accordance with the invention; FIGS. 2 and 3 are side and end views of one embodiment of the gate flasher assembly of FIG. 1 and is constructed in accordance with the invention; FIGS. 4 and 5 are top and side views of one embodiment of a foundation for the gate flasher assembly of FIGS. 2 and 3 and is constructed in accordance with the invention; FIGS. 6 and 7 are side and end views of one embodiment of a seal plate assembly for the gate flasher assembly of FIGS. 2 and 3 and is constructed in accordance with the invention; FIGS. 8 and 9 are enlarged side and end views of one embodiment of the seal plate for the seal plate assembly of FIGS. 6 and 7 and is constructed in accordance with the invention; and FIG. 10 is an exploded view of one embodiment of a gate flasher assembly constructed in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1-10 , embodiments of a system, method and apparatus for a railroad crossing gate flasher assembly having a sealed, rodent-proof connection for a utility mast assembly are disclosed. As shown in FIG. 1 , one embodiment of a railroad crossing comprises a railroad 11 for trains and a road 13 for roadway traffic 15 that crosses the railroad 11 . One or more railroad crossing gate flasher assemblies 17 are located adjacent to an intersection between the railroad 11 and the road 13 . In the configuration shown, one gate flasher assembly 17 is located on each side of the railroad 11 . A control box 14 is located in the vicinity of the intersection and provides electrical power and control signals to gate flasher assemblies 17 via underground wiring 29 . In one embodiment, each of the gate flasher assemblies 17 may comprise an arm or gate 19 that is movable between a lower position ( FIG. 1 ) that extends over the road 13 to prevent automobiles 17 from crossing the railroad 11 , and an upper position ( FIGS. 2 and 3 ) that is substantially vertical and does not extend over the road 13 . The gate flasher assembly 17 also comprises a junction box 20 (e.g., a cast housing) having a gate swing mechanism 21 for moving the gate 19 . The gate flasher assembly 17 also comprises warning lights 23 ( FIG. 1 ) and a bell 25 or other audible device. Each of these devices is provided with signals via wiring 29 ( FIGS. 2 and 3 ). As noted previously, the wiring 29 originates from control box 14 and extends underground. When wiring 29 emerges from the ground adjacent gate flasher assembly 17 , it is completely shielded and protected by an electrical conduit 27 that extends from the ground to an interior of the gate flasher assembly 17 . In the illustrated embodiments of FIGS. 2-5 , each gate flasher assembly 17 also may comprise a foundation 31 . The foundation 31 may comprise upper and lower horizontal plates 33 and a plurality of structural members 35 mounted therebetween. A plurality of bolts 37 (e.g., four shown) extend through bolt holes at an upper end of the foundation 31 (e.g., through upper plate 33 ) and extend upward above the upper end of the foundation 31 and upper plate 33 . In addition, a plurality of nuts 39 are threadingly secured on each of the bolts 37 (e.g., four on each bolt). The nuts 39 are movable relative to the bolts 37 for adjusting a vertical elevation thereof. In one embodiment, each bolt 37 has one nut 39 located below upper plate 33 , and three nuts 39 located above upper plate 33 , such that the upper plate 33 is captured between the first and second nuts 39 on each bolt 37 . As shown in FIGS. 2 and 3 , the bolts 37 and nuts 39 are used to mount the junction box 20 to the foundation 31 . The junction box 20 has a lower base or flange 22 with bolt holes through which the bolts 37 extend. In one embodiment, the flange 22 is captured between the third and fourth nuts 39 on each bolt 37 as shown. The flange 22 also has an aperture 24 extending through a lower end thereof that permits access into an interior thereof for electrical wiring. Referring now to FIGS. 2 , 3 and 6 - 9 , embodiments of the invention also comprise a seal plate 41 located on the foundation 31 . The seal plate 41 has a plate 43 that is mounted to the bolts 37 between, e.g., the third and fourth nuts 39 on each bolt 37 . Thus, the plate 43 directly abuts upper ones of the nuts 39 on the bolts 37 such that the plate 43 is elevated above the top of upper plate 33 by a space or clearance 36 ( FIGS. 2 and 3 ). When leveled, the plate 43 is substantially horizontal and located above the foundation 31 . The seal plate 41 may be leveled by adjustment of the nuts 39 for proper orientation of lights 23 ( FIG. 1 ) on, e.g., gate 19 . Lights 23 should be properly oriented for visibility by the drivers of roadway traffic 15 from a distance D of 500 feet. As best shown in FIGS. 8 and 9 , the plate 43 has an opening or electrical wiring port 45 that extends therethrough and a pattern of bolt holes 47 that align with the bolt hole pattern formed on flange 22 and upper plate 33 through which the bolts 37 extend. A coupling 49 is aligned with and extends downwardly from the electrical wiring port 45 through a hole 34 ( FIG. 4 ) in upper plate 33 . The hole 34 is sufficiently large to allow articulation of coupling 49 therein when seal plate 41 is leveled. The junction box 20 is mounted on top of and directly abuts the seal plate 41 , such that the junction box 20 is leveled by the leveling of the seal plate 41 . In one embodiment, the junction box includes a removable cover that can be removed without removing the seal plate. The electrical wiring 27 (see, e.g., FIGS. 2 and 3 ) extends downward from the junction box 20 through the aperture 24 , the electrical wiring port 45 and coupling 49 of the plate 43 , and within the conduit 27 extending through an interior of the foundation 31 . In this way, the plate 43 and coupling 49 cover the aperture 24 in the junction box 20 to protect the wiring. In addition, a connector 51 is mounted to and located below the coupling 49 of the plate 43 , and the conduit 27 is connected to and located below the connector 51 for protecting the electrical wiring 29 . The conduit 27 extends from the interior of the foundation 31 to an exterior of the foundation 31 . In another embodiment, the invention may comprise a railroad crossing gate flasher assembly having a foundation adapted to be located adjacent to an intersection between a railroad for trains and a road for automobiles. A junction box is mounted to the foundation and has a gate that is movable between upper and lower positions. Electrical wiring extends downward through an aperture on a lower end, and the junction box is above and spaced apart from the foundation. A seal plate is positioned between the foundation and the junction box and has a plate with an electrical wiring port and a coupling extending downwardly therefrom. A connector is mounted to and located below the coupling, and a conduit is connected to and located below the connector. The electrical wiring extends from the aperture and through the electrical wiring port, coupling, connector and conduit for protecting the electrical wiring from the junction box to an exterior of the foundation. In one embodiment, the coupling, connector and conduit extend through an interior of the foundation, and the conduit extends from the interior of the foundation to the exterior of the foundation. The railroad crossing gate flasher assembly may further comprise warning lights, a bell, and a gate swing mechanism for moving the gate, the warning lights, bell and gate swing mechanism being provided with electrical power and signals by the electrical wiring. The plate may be leveled above the foundation for leveling the junction box and is substantially horizontal. For example, the plate may be leveled on bolts extending through an upper end of the foundation, and nuts on each of the bolts that are movable relative to the bolts for leveling the plate. In still another embodiment, the invention may comprise a complete railroad crossing having a railroad for trains, and a road for vehicular traffic (e.g., automobiles) that crosses the railroad and forms an intersection therebetween. A warning system is located at the intersection for alerting drivers of automobiles of trains in a vicinity of the intersection. The warning system comprises a gate flasher assembly and a control box for distributing electrical power and control signals to the gate flasher assembly via electrical wiring. The gate flasher assembly may comprise a foundation and a junction box mounted to the foundation with the electrical wiring extending downward through an aperture on a lower end, the junction box being above and spaced apart from the foundation. A seal plate is positioned between the foundation and the junction box and comprises a plate having an electrical wiring port with a coupling extending downwardly therefrom, a connector mounted below the coupling, and a conduit mounted below the connector, such that the electrical wiring extends from the aperture and through the electrical wiring port, coupling, connector and conduit for protecting the electrical wiring from the junction box to the control box. In yet another embodiment, a utility mast assembly comprises a foundation, a plurality of bolts extend through an upper end of the foundation and extending upward above the upper end of the foundation. A plurality of nuts are on each of the bolts, and the nuts are movable relative to the bolts for adjusting their vertical elevation. A seal plate is located on the bolts and directly abuts upper ones of the nuts on the bolts. The seal plate comprises a flat plate that is substantially horizontal and located above the upper end of the foundation and which is leveled by adjustment of the nuts. The plate has an electrical wiring port that extends therethrough, and a pattern of bolt holes through which the bolts extend. A coupling is aligned with and extends downwardly from the electrical wiring port away from the plate. A junction box is mounted on top of and directly abutting the seal plate. The junction box has a pattern of bolt holes that align with the pattern of bolt holes in the plate and through which the bolts extend, and electrical wiring extending downward through an aperture on the lower end of the junction box, the electrical wiring port and coupling of the plate, and an interior of the foundation, such that the plate and coupling otherwise cover the aperture in the junction box. In still another embodiment, the invention may comprise a utility mast assembly having a utility mast that extends in a vertical direction above ground with a junction box at a lower end thereof. The junction box includes a bottom aperture through which electrical wires extend up into the utility mast. As illustrated in the various drawings, an in-place foundation is adapted to be preassembled and buried in the ground to form a foundation for supporting the utility mast in the vertical direction. A seal plate is positioned between the foundation and the junction box, and is attached to the foundation with a gap therebetween so that the seal plate can be leveled relative to the foundation. The seal plate also is attached to the junction box and comprises a plate having an electrical wiring port with a coupling extending downwardly therefrom, a connector mounted to and located below the coupling, and a conduit connected to and located below the connector. The electrical wiring extends from the aperture and through the electrical wiring port, coupling, connector and conduit, such that the seal plate, coupling and connector form a rodent-proof seal between the junction box and the conduit. The junction box may include a removable cover that can be removed without removing the seal plate. While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.	A railroad crossing gate flasher assembly has a sealed, rodent-proof connection for electrical cables that pass from the foundation to a junction box. A clearance between the bottom of the junction box and the top of the foundation is sealed with a plate to prevent rodents from accessing the cables. The seal plate is mounted to the bolts that extend from the foundation and is leveled after it is inserted onto the bolts. The junction box is lowered onto the seal plate and attached to the same bolts so that the junction box also is level. The seal plate has an opening, coupling and conduit for protecting the cables.	4
This is a continuation of copending application Ser. No. 08/466,042 filed on Jun. 6, 1995. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polymeric compounds which increase, in a liquid crystal display element comprising a liquid crystal layer having a polymer wall and a liquid crystal region substantially surrounded by said polymer wall, the orientation restricting force of a liquid crystal material present in said liquid crystal regions in an interface between said liquid crystal material and said polymer wall, and also relates to a liquid crystal display element using the polymeric compound. The liquid crystal display element of this invention can be utilized for personal display devices such as word processors, personal computers, and the like. The liquid crystal display element can also be utilized in devices used by a number of people such as portable information end devices, and the like. 2. Description of the Related Art Liquid crystal display elements using a liquid crystal material and a polymer material: (1) Japanese Laid-open Patent Publication No. 58-501631 discloses, a polymer dispersed liquid crystal display element which comprises a polymer material and a liquid crystal material encapsulated by the polymer material which displays the scattering state of an incident light by the refractive index difference between the liquid crystal material and the polymer material, and also displays the transparent state by the variation of the refractive index of the liquid crystal material with the impression of an electric voltage. Japanese Laid-open Patent Publication No. 61-502128 discloses a liquid crystal display element comprising a liquid crystal layer in which the phases of the liquid crystal material and the cured resin are three-dimensionally separated by irradiating a mixture of the liquid crystal material and the photocurable resin with ultraviolet ray. These elements are basically liquid crystal display elements which control electrically the scattering-transparency variation of an incident light in the liquid crystal layer. (2) Japanese Laid-open Patent Publication No. 1-269922 discloses a technique for preparing liquid crystal regions with different characteristics by first exposing to ultraviolet ray a liquid crystal layer comprising a photocurable resin and a liquid crystal material through a photo-mask, and further irradiating it with ultraviolet ray after remove the photo-mask. The element thus obtained is basically a scattering type element. Japanese Laid-open Patent Publication No. 5-257135 discloses an element comprising a liquid crystal layer obtained by oppositely placing a substrate equipped with an alignment film having an orientation restricting force through a pair of gaps, injecting a mixture of a liquid crystal material and a photocurable resin into the gaps, and then irradiating the mixture with ultraviolet rays through a photo-mask disposed on the surface of said substrate. Since the inner portion of the liquid crystal layer in which the photo-mask is disposed has different threshold values and different optical characteristics obtained from the impression of an electric voltage from those of the outer portion of the liquid crystal layer, the element is a static driving element in which the pixel patterns are varied due to the electric voltage. The principal behind the improvement of the viewing angle characteristics of a liquid crystal display element: In order to improve the viewing angle characteristics of a liquid crystal display element, it is necessary to orient each of the liquid crystal molecule toward three or more different directions inside the pixels (liquid crystal regions). If each of the liquid crystal molecules inside the liquid crystal layer is oriented in three or more different directions, the apparent refractive index of each of the liquid crystal molecules is averaged in the gray scale state when viewing the pixels from both A and B directions as described in FIG. l(b). In other words, the contrast of the display element is substantially identical from both A and B directions. Therefore, the viewing angle characteristics of the element having such an orientation state of the liquid crystal as shown in FIG. 1(b) are improved, compared to those of the element having a TN mode shown in FIG. 2. Specific examples of the elements having a wide viewing angle mode: (1) Japanese Laid-open Patent Publications Nos. 4-338923 and 4-212928 disclose a wide viewing angle mode comprising a combination of the aforementioned polymer dispersed liquid crystal element and polarizing plates, which are attached to both surfaces of the element such that each of the polarization axes of the plates are at a right angle to each other. (2) As a method for improving the viewing angle characteristics of a non-scattering type liquid crystal display element using a polarizer, Japanese Laid-open Patent Publication No. 5-27242 discloses a method for preparing a composite material of a liquid crystal and a polymer from a mixture of the liquid crystal and a photocurable resin by the phase separation. According to this method, the orientation of the liquid crystal domains becomes random due to the polymer thus prepared. Therefore, because the liquid crystal molecules are oriented in different directions in each domain at the time of impressing an electric voltage, the apparent refractive indices viewed from each direction are substantially identical, and the viewing angle characteristics are improved in the gray scale state. (3) In recent years, the present inventors have proposed a liquid crystal display element comprising a liquid crystal region in which the liquid crystal molecules are omnidirectionally (spirally) oriented in the portions where a photo-mask is present, and a polymer wall which consists mainly of a photocurable resin in the other portions. The liquid crystal region and polymer wall are formed by irradiating through the photo-mask a cell having a liquid crystal composition comprising the photocurable resin and the liquid crystal material. When the liquid crystal molecules of the liquid crystal display element are controlled by an electric voltage, the spiral orientation of the liquid crystal molecules will act as if an umbrella opened and closed to improve significantly the viewing angle characteristics. In the interface between the polymer wall and the liquid crystal material of the element described in (3), disclination lines are generated due to the reverse tilt of the liquid crystal molecules at the time of impressing an electric voltage. Since the disclination lines are displayed as bright lines, the viewing angle characteristics of the element are deteriorated, when the display state is in a black state. The prevent inventors have found that the addition of a polymeric compound to a mixture of the liquid crystal material and the photocurable resin in order to prevents the generation of the disclination lines in these elements. However, because the addition of the conventional polymeric compounds enlarges the pretilt angle of the liquid crystal material in the liquid crystal regions, the brightness of the element is reduced in the absence of an electric voltage. The present inventors have eagerly examined the relationship between the structure of the polymeric compounds and the orientation of the liquid crystal molecules in the interface between the liquid crystal material and the polymer wall, and found a compound from which a liquid crystal display element is obtained generating no disclination lines and also having bright characteristics in the absence of an electric voltage. SUMMARY OF THE INVENTION The polymeric compound of this invention is represented by the following general formula (I): ##STR4## wherein A represents a hydrogen atom or ##STR5## B represents a hydrogen atom or ##STR6## each of X 1 and X 2 represents independently a hydrogen atom or a methyl group, each of m and n represents independently an integer of 0 to 14, each of p and q represents independently 0 or 1, and each of Y 1 , Y 2 , Y 3 , and Y 4 represents independently a hydrogen atom or a fluorine atom, with the proviso that both A and B are not hydrogen atoms, p is 0 when m is 0, and q is 0 when n is 0. In a preferred embodiment, in the general formula (I) A represents: ##STR7## and B represents: ##STR8## In a preferred embodiment, in the general formula (I) either A or B represents a hydrogen atom. In a preferred embodiment, in the general formula (I) A represents a hydrogen atom or: ##STR9## B represents a hydrogen atom or: ##STR10## a preferred embodiment, in general formula (I) both p and q represent 1. In a preferred embodiment, in the general formula (I) A represents: ##STR11## and B represents a hydrogen atom. Alternatively, represents a hydrogen atom and B represents: ##STR12## In a preferred embodiment, in the general formula (I) at least one selected from the group consisting of Y 1 , Y 2 , Y 3 and Y 4 is a fluorine atom. The liquid crystal display element of this invention comprises a pair of substrates oppositely disposed through a gap, and a liquid crystal layer placed in the gap. At least one of the substrates is transparent, and the liquid crystal layer includes a liquid crystal region, and a polymer wall surrounding the liquid crystal region, wherein the liquid crystal layer includes a liquid crystal material, a polymeric polymer material, and the above-described polymeric compound. In a preferred embodiment, the liquid crystal region includes liquid crystal molecules, and the orientation of the liquid crystal molecules is either random, radial, concentric or spiral. In a preferred embodiment, an alignment film is placed on the substrates. In a preferred embodiment, the liquid crystal region includes liquid crystal molecules, and the orientation of the liquid crystal molecules is TN, STN, ECB or FLC. In a preferred embodiment, the polymeric polymer material is a photocurable resin. In a preferred embodiment, the polymeric compound is represented by the general formula (I), wherein either A or B represents a hydrogen atom. In a preferred embodiment, the polymeric compound is represented by the general formula (I), wherein A represents: ##STR13## and B represents: ##STR14## When a display mode utilizing an orientation restricting force on the substrate is prepared from a mixture of a liquid crystal material and a polymeric polymer material such as a photocurable resin, the orientation restricting force of the alignment film to the liquid crystal molecules generally tends to be weakened due to the formation of a polymer layer consisting of the polymeric polymer material between the alignment film and the liquid crystal region. However, when the polymeric compound of this invention is contained in the polymer layer, an ability of transferring the orientation restricting force of the alignment film to the liquid crystal molecules inside the liquid crystal regions is also created in the polymer layer to stabilize the orientation of the liquid crystal molecules, due to the presence of a material having a structure similar to the liquid crystal material in the polymer layer. When the liquid crystal molecules present inside the liquid crystal region are oriented symmetrical with respect to the axis (an axis which is at a right angle to the surface of the substrate), disclination lines are normally generated on the periphery of the liquid crystal region due to the reverse tilt (See, FIG. 2) at the time of impressing an electric voltage. However, because the addition of the polymeric compound of this invention results in the generation of the pretilt of the liquid crystal molecules on the substrate, the generation of the disclination lines is controlled at the time of impressing an electric voltage which deteriorate the black display level. Thus, the contrast of the display element is dramatically improved. Therefore, the invention described herein makes possible the advantages of providing a liquid crystal display element which has the following effects. (1) Since the liquid crystal regions are surrounded by the polymer wall, the gap is maintained between both substrates by the polymer wall. Therefore, it is possible to control the deformation of the liquid crystal display element against an external force, especially to control the variation of its color which results when the surface of the element is pressed by a pen. (2) The conventional large screen liquid crystal display elements which are placed vertically have different thicknesses in the upper and lower portions due to the presence of gravity. This causes the unevenness of the display. However, because the substrates of the liquid crystal display element of this invention are attached throughout the whole surface of the element, the thickness of the cell is not often varied. (3) It is possible to make the orientation of the liquid crystal molecules in the liquid crystal regions random, concentric, radial or spiral by utilizing effectively the phase separation between the liquid crystal material and the polymer wall consisting mainly of the polymeric polymer materials at the time of curing the liquid crystal composition. Since the liquid crystal of the liquid crystal regions is oriented symmetrically to the axis, the liquid crystal display element thus obtained has excellent viewing angle characteristics. (4) It is possible to strengthen the orientation restricting force in the interface between the liquid crystal material and the polymer layer by using the polymeric compound of this invention. (5) The liquid crystal display element of this invention is suitable for personal display devices such as word processors, personal computers, and the like; and devices used by a number of people (especially, those used on a desk surrounded by 2-4 people) such as portable information end devices, and the like. These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged view showing the liquid crystal region of the liquid crystal display element of this invention; FIG. 2 is a diagram showing the viewing angle characteristics of a TN mode element; FIG. 3 is a diagram showing the generation of the disclination lines at the time of impressing an electric voltage; FIG. 4 is an enlarged diagram showing the liquid crystal region using a bifunctional polymeric compound; FIG. 5 is a diagram of the photo-mask used in Example 9; FIG. 6 is an enlarged diagram of the cell prepared in Example 9; FIG. 7 is a series of graphs showing the electrooptical characteristics (viewing angle characteristics) of the element prepared in Example 9; and FIG. 8 is a series of graphs showing the electrooptical characteristics (viewing angle characteristics) of a TN mode element. DESCRIPTION OF THE PREFERRED EMBODIMENTS The polymeric compound of this invention has a functional group reactive with a polymeric polymer material, including monofunctional polymeric compounds and polyfunctional polymeric compounds. 1. The monofunctional polymeric compounds A. Structure The monofunctional polymeric compound is a compound in which one polymeric functional group is present in its molecule and bonded to a mesogen group having liquid crystal properties. B. Effects The following illustrate the effects attained by the use of the polymeric compound. When a display mode utilizing an orientation restricting force on the substrate is prepared from a mixture of a liquid crystal material and a polymeric polymer material such as a photocurable resin, the orientation restricting force of the alignment film to the liquid crystal molecules generally tends to be weakened due to the formation of a polymer layer consisting of the polymeric polymer material between the alignment film and the liquid crystal region. However, when the polymeric compound of this invention is contained in the polymer layer, an ability to transfer the orientation restricting force of the alignment film to the liquid crystal molecules inside the liquid crystal region is also created in the polymer layer to stabilize the orientation of the liquid crystal molecules. This is due to the presence of a material having a structure similar to the liquid crystal material in the polymer layer. When the liquid crystal molecules present inside the liquid crystal region are oriented symmetrical with respect to the axis (the axis X which is shown in FIG. 1(a) and is at a right angle of the surface of the substrate), the disclination lines d are normally generated on the periphery of the liquid crystal region due to the reverse tilt (See, FIG. 3) at the time of impressing an electric voltage. However, because the addition of the polymeric compound of this invention results in the generation of the pretilt of the liquid crystal molecules on the substrate, the generation of the disclination lines is controlled at the time of impressing an electric voltage (which is estimated to be due to the fact that the liquid crystal molecules are oriented nearly at a right angle at the time of impressing the electric voltage). C. The influence derived from the variation of the chain length of the linking groups in the polymeric compound The numbers, n and m of the linking groups, --(CH 2 ) m --or--(CH 2 ) n --which connect the mesogen group to the polymeric functional group may influence the viewing angle characteristics of the liquid crystal display element thus prepared. In the above formula, m and n are 0 to 14, respectively. Preferably, m and n are 0 or 3 to 14 and more preferably 4 to 7, respectively. If both m and n are 2, the polymeric compound is too reactive to be practical. If both m and n exceed 14, the mesogen portions appear on the surfaces of the polymer wall and the polymer layer so that the response speed is reduced, which is estimated to be due to the fact that the mesogen groups are oriented in the same manner as the liquid crystal molecules. The longer the chain length of the linking groups is, the smaller the amount of the polymeric compound required to obtain an effect on controlling the disclination lines. However, at the same time, the pretilt angle is enlarged to reduce the transmittance of the cell. Thus, it is necessary to select the amounts added and types of the polymeric compound so as to control the disclination lines and also prevent the pretilt angle from enlarging. D. The effects of the fluorination of the polymeric compound on the viewing angle characteristics of the element There will be the following problems (a)-(d) arising in an element comprising a liquid crystal layer having a liquid crystal region and a polymer wall surrounding the liquid crystal region, the liquid crystal region and the polymer wall being formed by the phase separation of a mixture of a liquid crystal material and a polymeric polymer material by the polymerization reaction. Problems Estimated Causes (a) Slow response speed--The dissolution of the polymer material, monomers in the liquid crystal; (b) The generation of hysteresis--The strong anchoring strength of the liquid crystal molecules to the polymer wall; (c) High driving voltage--The same as above item (b) (d) The leakage of the light at the time of impressing a saturation voltage--The dissolution of the liquid crystal molecules in the polymer layer inside the liquid crystal region, and the strong anchoring strength of the liquid crystal molecules to the polymer wall. The causes of the above-described problems are due to the strong anchoring strength of the liquid crystal molecules to the polymer wall, as well as the good compatibility between the polymer material and the liquid crystal material. Both of these problems may be solved by the use of a fluorinated polymeric compound. Since the fluorinated polymeric compound is expected to appear on the surfaces of the polymer wall and the polymer layer, the orientation of the liquid crystal may be stabilized. 2. The polyfunctional polymeric compounds A. Structure The polyfunctional polymeric compound is a compound in which a plurality of the polymerizable functional groups are bounded to the mesogen group having liquid crystal properties. The number of the functional groups is preferably 2. If it is 3 or more, the polymer wall is formed before the liquid crystal region is largely developed due to the fact that the gelation speed of the liquid crystal material becomes faster, and therefore the transmittance of the liquid crystal display element thus prepared is reduced in the absence of an electric voltage. The numbers, n and m, of the linking groups --(CH 2 ) m -- or --(CH 2 ) n -- which connect the above-described mesogen group to the polymeric functional group are the same as those for the above-described monofunctional polymeric compound, but are preferably 12 or less. If they exceed 12, the solubility of the polymeric compound in the liquid crystal material is reduced. B. Effects Like the monofunctional polymeric compound, the polyfunctional polymeric compound has an effect on stabilizing the orientation of the liquid crystal molecules. Moreover, with respect to the generation of disclination lines, the polyfunctional polymeric compound provides an observed image which has a region having a smaller amount of twisting, as is shown in FIG. 4, than obtained by the use of the monofunctional polymeric compound, and generates no disclination lines at the time of impressing an electric voltage. The use of a fluoridized polyfunctional polymeric compound provides the same effects as those of the monofunctional polymeric compound. In this case, the site which is fluoridized may be located on the carbon inside the mesogen backbone. 3. Retardation : d·Δn , d: thickness of the liquid crystal layer, Δn :birefringence Since the liquid crystal molecules are nearly upright to the substrate (when Δε>0) in the liquid crystal display element of this invention having a polarizer at the time of impressing a saturation voltage, (1) the polarizer has viewing angle characteristics, and (2) the liquid crystal layer has retardation of d·Δn. Therefore, there is a region having poor viewing angle characteristics in the direction of 45° from the polarization axis of the polarizer. The cause of the above-described problem (2) is that light entering from the polarization direction of the polarizer has either an ordinary ray only or an extraordinary ray only in crossing the refractive index ellipsoid of the liquid crystal layer, and incident light entered in the direction of 45° from the polarization axis of the polarizer has both an ordinary ray and an extraordinary ray in crossing the refractive index ellipsoid of the liquid crystal layer. This causes leakage of the light due to the generation of elliptic polarization. Thus, it is preferred that the retardation of the liquid crystal layer be as small as possible so that the elliptic polarization is not easily produced. However, because the transmittance T 0 in the absence of an electric voltage is influenced by the retardation of the liquid crystal layer, it is preferred in view of ensuring the omnidirectional properties of the viewing angle characteristics and the brightness of the cell that the retardation of the liquid crystal layer be 300 nm to 650 nm. If the retardation is less than 300 nm, the cell shows a dark display due to the lack of the brightness in the absence of an electric voltage. It is preferred that the twist angle be 45° to 150°, and especially be in the neighborhood of 90° which satisfies the first minimum conditions because the cell has the highest brightness at this angle. 4. Liquid crystal display elements The liquid crystal display element of this invention comprises two substrates 1a and 1b, both of which are oppositely placed with a gap therebetween, and a liquid crystal layer 2 placed inside the gap, as shown in FIG. 1. At least one of the two substrates 1a and 1b may be transparent. The liquid crystal layer 2 has a number of liquid crystal regions 20, and a polymer wall 21 surrounding the liquid crystal regions 20. An exemplary, liquid crystal display element is prepared as follows. Two substrates in which transparent electrodes are provided are placed with a gap therebetween by the use of a spacer to form a cell. On one side of the cell, a photo-mask 3 is disposed as shown in FIG. 5. A liquid crystal composition containing a liquid crystal material, a polymeric polymer material, and at least one of the above-described polymeric compounds is injected into the cell. Then, the cell is irradiated with ultraviolet ray on the photo-mask side while impressing an electric voltage between the transparent electrodes. The polymeric polymer material and polymeric compounds in the liquid crystal composition in the cell are polymerized and cured by the irradiation of the ultraviolet ray. In the process of the polymerization, the phases of the liquid crystal material and the polymeric polymer material in the liquid crystal composition are separated to form liquid crystal regions 20 surrounded by polymer walls consisting of the polymeric polymer material and the polymeric compounds in portions 30 which correspond to the above-described photo-mask, as shown in FIG. 6. Polymeric polymer materials which can be used in the above-described display element include known polymerizable resins which are preferably photocurable resins. These photocurable resins include, for example, acrylic acids and acrylates having a long chain alkyl group of 3 or more carbons or a benzene ring, including isobutyl acrylate, stearyl acrylate, lauryl acrylate, isoamyl acrylate, n-butyl methacrylate, n-lauryl methacrylate, tridecyl methacrylate, 2-ethylhexyl acrylate, n-stearyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, and the like. The photocurable resins also include polyfunctional resins to increase the physical strength of the polymer material such as bisphenol A dimethacrylate, bisphenol A diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetracrylate, neopentyl diacrylate, and the like. 5. Driving methods The liquid crystal display element thus prepared may be driven by a driving method such as simple matrix driving and active driving method including for example a--Si TFT, p--Si TFT, MIM, and the like, but the driving method is not particularly limited in the present invention. 6. Substrate materials The substrate materials that can be used in the present invention include glass plates, plastic plates, and the like which are made from transparent solids, and substrates with a thin metal film, Si substrates, and the like which are made from non-transparent solids. The substrates with a thin metal film are effective for a reflection type liquid crystal display element. The plastic substrate is preferably made from a material which does not absorb visible light, including for example PET, acrylic polymers, polystyrenes, polycarbonates, and the like. Also, when the plastic substrate is used, the polarization ability may be imparted to the substrate itself. Moreover, a laminated substrate made by combining two types of different substrates, or a laminated substrate made by combining two substrates of either the same or different types having different thicknesses may also be used. The following illustrate the outline of a method for synthesizing the above-described polymeric compound. The following synthesis routes are illustrative examples, and the present invention is not limited to these examples. 7. Synthesis routes Synthesis route 1: The compound represented by the general formula (I); ##STR15## (Note) The symbol, MOM indicates CH 3 OCH 2 -group Synthesis route 2: The compound represented by the general formula (I), wherein A and B are the same group; ##STR16## Synthesis route 3: The compound represented by the general formula (I), wherein either A or B is hydrogen atom; ##STR17## Synthesis route 4: The synthesis of the intermediate compound; ##STR18## The following outline the synthesis routes 1-4. Synthesis route 1: The compounds represented by the general formulae (1), (4), (5), (6), (7) and (8) are commercially available. Also, the compound represented by the general formula (3), where each of Y 1 and Y 2 is a hydrogen atom or a fluorine atom is also commercially available. The compound represented by the general formula (1) is reacted with C 4 H 9 Li and thereafter with B(OCH 3 ) 3 , and hydrolyzed to obtain the compound represented by the general formula (2) which is then oxidized using hydrogen peroxide to obtain the compound represented by the general formula (3). The compound represented by the general formula (3) is etherified with the compound represented by the general formula (8) to obtain the compound represented by the general formula (16) which is then esterified with the compound represented by the general formula (7), or the compound represented by the general formula (3) is directly esterified with the compound represented by the general formula (7) to obtain the compound represented by the general formula (17). The compound represented by the general formula (4) is etherified with methoxymethyl chloride (MOM-Cl) to obtain the compound represented by the general formula (13) which is then reacted with C 4 H 9 Li and thereafter with B(OCH 3 ) 3 , and hydrolyzed to obtain the compound represented by the general formula (15). Also, the compound represented by the general formula (5) is etherified with MOM-Cl to obtain the compound represented by the general formula (14) which is then reacted with magnesium (Mg) to form a Grignard reagent. The compound represented by the general formula (15) may also be obtained by reacting the Grignard reagent with B(OCH 3 ) 3 . The compound represented by the general formula (17) which is obtained by the above-described procedure is coupled with the compound represented by the general formula (15) in the presence of a palladium (Pd) catalyst to obtain the compound represented by the general formula (18). The methoxymethyl (MOM) group of the compound represented by the general formula (18) is eliminated under the acidic conditions to obtain the compound represented by the general formula (19) which is then esterified or etherified with the compound represented by the general formula (8), or the compound represented by the general formula (12) (Synthesis route 4), respectively to obtain the compound represented by the general formula (I). Synthesis route 2: The compound represented by the general formula (20) which is obtained by etherifying the compound represented by the general formula (3) with MOM-Cl is coupled with the compound represented by the general formula (15) which is obtained in the above-described synthesis route 1 in the presence of a Pd catalyst to obtain the compound represented by the general formula (21). The MOM Group of the compound represented by the general formula (21) is eliminated under the acidic conditions to obtain the compound represented by the general formula (22). The compound represented by the general formula (22) is esterified or etherified with the compound represented by the general formula (7) or the compound represented by the general formula (11) (Synthesis route 4), respectively to obtain the compound represented by the General formula (I), wherein A and B are the same group. Synthesis route 3: The compound represented by the general formula (1) is coupled with the compound represented by the general formula (15) in the presence of a Pd catalyst to obtain the compound represented by the general formula (23). The MOM group of the compound represented by the general formula (23) is eliminated under the acidic conditions to obtain the compound represented by the general formula (24). The compound represented by the general formula (24) is esterified or etherified with the compound represented by the general formula (8) or the compound represented by the general formula (12), respectively, to obtain the compound represented by the general formula (I), wherein either A or B is a hydrogen atom. Synthesis route 4: The commercially available compound represented by the general formula (9) is esterified with the compound represented by the general formula (7) to obtain the compound represented by the general formula (11) Also, the compound represented by the general formula (10) is esterified by the compound represented by the general formula (8) to obtain the compound represented by the general formula (12). EXAMPLES The following are illustrative examples of the present invention. However, the present invention is not intended to be limited to these examples. Additionally, the abbreviations described in the present examples indicate the following: GC; Gas chromatography HPLC; High-performance liquid chromatography TLC; Thin layer chromatography IR; Infrared absorption spectrum Mass; Mass spectrum b.p.; Boiling point m.p.; Melting point GTO; Glass tube oven Y; Yield Example 1 (a) The synthesis of ##STR19## Into a reactor, 40 g of p-bromophenol and 200 ml of DMF (dimethylformamide) were charged, to which 10 g of a 60% NaH (sodium hydride) were gradually added to give a solution. To the solution, 18 g of methoxymethyl chloride were added dropwise with stirring at a temperature of 30° C. or lower, and reacted overnight at room temperature to give a reaction solution. The reaction solution was poured into water, extracted with benzene, washed with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was distilled under reduced pressure to give 38.4 g (Y., 79.3%) of 4-bromopheny methoxymethyl ether. b.p.; 65°-67° C./0.6 mmHg GC; 99.4% (b) The synthesis of ##STR20## Into a reactor, 100 g of 1,2-difluorobenzene and 350 ml of THF (tetrahydrofuran) were charged under an argon stream, to which 700 ml of a 1.6M C 4 H 9 Li (butyl lithium)/hexane solution were added dropwise with stirring at a temperature of -50° C. to -60° C. and stirred at the same temperature for 1 hour to give a solution. Thereafter, 175 g of (CH 3 O) 3 B (trimethyl borate) were added dropwise, and stirred at the same temperature for 1 hour. The mixture was stirred overnight while reducing the temperature gradually to room temperature. Thereafter, the mixture was cooled to 0° C., to which a dilute hydrochloric acid was added to give a reaction solution. The reaction solution was extracted with toluene, washed with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the crystallized residue was immersed into and washed with hot hexane to give 80.8 g (Y., 56.6%) of 2,3-difluorophenyl boronic acid. HPLC; 99.5% (c) The synthesis of ##STR21## Into a reactor, 5.1 g of Pd(PPh 3 ) 4 (tetrakistriphenylphosphine palladium), 210 ml of a benzene solution of 33 g of 4-bromopheny methoxymethyl ether obtained in the above-described synthesis (a), 135 ml of a 2M aqueous solution of Na 2 CO 3 , and 120 ml of an ethanol solution of 24 g of 2,3-difluorophenyl boronic acid obtained in the above-described synthesis (b) were charged under an argon stream, and stirred for 6 hours under reflux condition to give a reaction solution. The reaction solution was poured into water, extracted with toluene, washed with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was distilled under reduced pressure to give 20.1 g (Y., 53.6%) of 2,3-difluoro-4'-(methoxymethyl)biphenyl. b.p.; 110°-120° C./0.25 mmHg GC; 96.0% (d) The synthesis of ##STR22## Into a reactor, 20.1 g of 2,3-difluoro-4'-(methoxymethyl)biphenyl obtained in the above-described synthesis (c), 60 ml of THF, and 90 ml of a 6N-HCl were charged, and stirred for 3 hours under reflux condition to give a reaction solution. The reaction solution was cooled, and thereafter extracted with toluene, washed with water, dried over sodium sulfate anhydride, and the solvent was evaporated and the residue was distilled under reduced pressure to give 9.0 g (Y., 54.3%) of 2,3-difluoro-4'-hydroxybiphenyl. b.p.; .160°-170° C./18 mmHg m.p.; 132°-134.4° C. GC; 99.7% (e) The synthesis of ##STR23## Into a reactor, 4.0 g of 2,3-difluoro-4'-hydroxybiphenyl obtained in the above-described synthesis (d), 2.0 g of triethylamine, and 300 ml of benzene were charged, to which a solution of 1.9 g of acryloyl chloride in 100 ml of benzene was added dropwise, and stirred for 5 hours to give a reaction solution. The reaction solution was washed with a 3N-hydrochloric acid and then with water, and thereafter dried over sodium sulfate anhydride, and the solvent was evaporated and the residue was purified by the silica gel column chromatography (eluent; toluene), and then recrystalized from hexane to give 4.5 g (Y., 88.5%) of 2,3-difluorobiphenyl-4'-yl acrylate. m.p.; 88.4°-90.0° C. The purity of this material was 99.2% measured by GC, 99.5% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 260 by the Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Example 2 (a) The synthesis of CH 2 ═CHCOO(CH 2 ) 6 Br Into a reactor, 30 g of 6-bromo-1-hexanol, 18.4 g of triethylamine, and 500 ml of benzene were charged, to which a solution of 16.5 g of acryloyl chloride in 200 ml of benzene was added dropwise, while stirring and cooling with ice, and stirred for 3 hours to give a reaction solution. The reaction solution was washed with a 3N-HCl and then with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was purified by the silica gel column chromatography (eluent; toluene) to give 25.4 g (Y., 65.1%) of 6-bromohexyl acrylate. GC; 95.9% (b) The synthesis of ##STR24## Into a reactor, 4 g of 2,3-difluoro-4'-hydroxybiphenyly obtained in the above-described synthesis (d) of Example 1, 5.0 g of 6-bromohexyl acrylate obtained in the above-described synthesis (a), 5.4 g of K 2 CO 3 and 400 ml of 2-butanone were charged, and further stirred and refluxed for 28 hours to give a reaction solution. The reaction solution was poured into water, extracted with toluene, washed with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was purified by the silica gel column chromatography (eluent; toluene), and then recrystallized twice from hexane to give 5.35 g (Y., 76.5%) of 2,3-difluoro-4'- 6-(acryloyloxy)hexyloxy!biphenyl. m.p.; 45.6°-46.8° C. The purity of this material was 99.0% measured by GC, 99.0% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 360 by the Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Example 3 (a) The synthesis of CH 2 ═CHCOO(CH 2 ) 12 Br The same procedure as in the synthesis (a) of Example 2 was repeated except that 44.0 g of 12-bromo-1-dodecanol were used instead of 30 g of 6-bromo-1-hexanol to give 39.8 g (Y., 75.1%) of 12-bromododecyl acrylate. (b) The synthesis of ##STR25## The same procedure as in the synthesis (b) of Example 2 was repeated except that 6.7 g of 12-bromododecyl acrylate were used instead of 5.0 g of 6-bromohexyl acrylate to give 2.1 g (Y., 24.1%) of 2,3-difluoro-4'- 12-(acryloyloxy)dodecyloxy!biphenyl. m.p.; 59.7°-60.7° C. The purity of this material was 99.4% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 444 by Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Example 4 (a) The synthesis of ##STR26## In a reactor, 10.0 g of 4-bromophenol, 7.95 g of ethylene bromohydrin, 16.0 g of K 2 CO 3 , and 300 ml of acetone were charged, and stirred and refluxed for 50 hours to give a reaction solution. The reaction solution was poured into water, extracted with toluene, washed with water, and thereafter dried over sodium sulfate anhydride, and the solvent was evaporated and the residue was distilled under reduced pressure in GTO (glass tube oven) to give 5.55 g (Y., 44.3%) of 1-bromo-4-(2-hydroxyethoxy) benzene. GC; 96.8% b.p.; 100° C./0.1 mmHg (which was the prescribed temperature of GTO) (b) The synthesis of ##STR27## Into a reactor, a solution of 5.0 g of 4-(2-hydroxyethyl)oxy-bromobenzene in 150 ml of benzene, 7.2 g of 2,3-difluorophenyl boronic acid obtained in the synthesis (b) of Example 1, 68 ml of a 2M aqueous solution of Na 2 CO 3 , and 1.0 g of Pd(PPh 3 ) 4 were charged, and stirred and refluxed for 9 hours to give a reaction solution. The reaction solution was poured into water, extracted with toluene, washed with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was distilled under reduced pressure in GTO, and recrystallized from an ethanol/hexane (=1/1) mixed solvent to give 4.2 g (Y., 72.7%) of 2,3-difluoro-4'-(2-hydroxyethoxy)biphenyl. (c) The synthesis of ##STR28## Into a reactor, 2.0 g of 2,3-difluoro-4'-(2-hydroxyethoxy)biphenyl obtained in the above-described synthesis (b), 0.9 g of triethylamine, and 300 ml of diethylether were charged, to which a solution of 0.8 g of acryloyl chloride in 100 ml of diethylether was added dropwise, while stirring and cooling with ice, and stirred for 4 hours to give a reaction solution. The reaction solution was washed with a dilute hydrochloric acid and then with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was purified by the silica gel column chromatography (eluent; toluene) to give 0.72 g (Y., 29.6%) of 2,3-difluoro-4'- 2-(acryloyloxy)ethoxy!biphenyl. m.p.; 47.4°-50.1° C. The purity of this material was 99.4% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 304 by the Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Example 5 (a) The synthesis of ##STR29## Into a reactor, 2.1 g of Pd(PPh 3 ) 4 , a solution of 11.6 g of 1-bromo-2,3-difluorobenzene in 100 ml of benzene, 60 ml of a 2M aqueous solution of Na 2 CO 3 , and a solution of 13.3 g of 2,3-difluorophenyl boronic acid obtained in the synthesis (b) of Example 1 in 100 ml of ethanol were charged under an argon stream, and stirred for 6 hours under reflux condition to give a reaction solution. The reaction solution was washed with a dilute hydrochloric acid and then with water, dried over sodium sulfate anhydride, and the solvent was evaporated and the residue was distilled under reduced pressure to give 5.7 g (Y., 42%) of 2,2',3,3'-tetrafluorobiphenyl. (b) The synthesis of ##STR30## Into a reactor, 5.7 g of 2,2',3,3'-tetrafluorobiphenyl obtained in the above-described synthesis (a), and 50 ml of THF were charged under an argon stream, to which 38 ml of a 1.6M C 4 H 9 Li/hexane solution were added dropwise at a temperature of -50° C. or lower, and stirred at the same temperature for 2 hours, to which 10 g of (CH 3 O) 3 B (trimethyl borate) were added dropwise, and heated gradually to room temperature, and stirred overnight. To the reactor, a dilute sulfuric acid was added and stirred for 1 hour, and thereafter extracted with an ether, washed with water, dried over sodium sulfate anhydride, and the solvent was evaporated and recover the residue. To the residue, hexane was added, and then immersed and washed to give a crystal, to which 50 ml of THF were added to dissolve, followed by the addition of 40 ml of a 10% aqueous H 2 O 2 solution. This mixture was then stirred overnight at room temperature to give a reaction solution. The reaction solution was extracted by the addition of toluene, washed with water, dehydrated with sodium sulfate anhydride, and thereafter the solvent was evaporated and recover the residue (4.3 g of the crude 2,2',3,3'-tetrafluoro-4,4'-dihydroxybiphenyl). GC; 92% (c) The synthesis of CH 2 ═CHOO(CH 2 ) 8 Br The same procedure as in the synthesis (a) of Example 2 was repeated except that 34.7 g of 8-bromo-1-octanol were used instead of 30 g of 6-bromo-1-hexanol to give 34.1 g (Y., 78%) of 8-acryloyloxy-1-bromooctane. GC; 97% (d) The synthesis of ##STR31## Into a reactor, 4.3 g of the crude 2,2',3,3'-tetrafluoro-4,4'-dihydroxybiphenyl obtained in the above-described synthesis (b), 10.0 g of 8-acryloyloxy-1-bromooctane obtained in the above-described synthesis (c), 7.8 g of K 2 CO 3 , and 30 ml of acetone were charged, and refluxed and stirred for 16 hours to give a reaction solution. The reaction solution was filtered through a filter aid (Highflow) to give a filtrate, to which toluene was added, and washed with water, dried over sodium sulfate anhydride, and thereafter the solvent was evaporated and the residue was purified twice by the silica gel column chromatography (eluent; toluene/ethyl acetate=20/1), and then recrystallized from acetone to give 1.28 g (Y,. 12.9%) of 4,4'-bis 8-(acryloyloxy)octyloxy!-2,2',3,3'-tetrafluorobiphenyl. m.p.; 60.5°-61.4° C. The purity of this material was 99.7% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 622 by Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Example 6 (a) The synthesis of ##STR32## The same procedure as in the synthesis (a) of Example 1 was repeated except that 30 g of 2,3-difluorophenol were used instead of 40 g of p-bromophenol to give 32.6 g (Y., of 81.4%) methoxymethyl-2,3-difluorophenyl ether. GC; 99.6% b.p.; 82°-84° C./14 mmHg (b) The synthesis of ##STR33## The same procedure as in the synthesis (b) of Example 1 was repeated except that 152.2 g of methoxymethyl-2,3-difluorophenyl ether obtained in the above-described synthesis (a) were used instead of 100 g of 1,2-difluorobenzene to give 150.6 g (Y., 78.8%) of 2,3-difluoro-4-(methoxymethoxy)phenyl boronic acid. HPLC; 97.4% (c) The synthesis of ##STR34## The same procedure as in the synthesis (c) of Example 1 was repeated except that 32.7 g of 2,3-difluoro-4-(methoxymethyl)oxyphenyl boronic acid obtained in the above-described synthesis (b) were used instead of 24 g of 2,3-difluorophenyl boronic acid to give 23.4 g (Y., 95.0%) of 2,3-difluoro-4,4'-bis(methoxymethoxy)biphenyl. GC; 96% (d) The synthesis of ##STR35## The same procedure as in the synthesis (d) of Example 1 was repeated up to the distillation step of the solvent except that 24.2 g. of 2,3-difluoro-4,4'-bis(methoxymethoxy)-biphenyl obtained in the above-described synthesis (c) were used instead of 20.1 g of 2,3-difluoro-4'-(methoxymethoxy)biphenyl to give 17 g of the residue (the crude 2,3-difluoro-4,4'-dihydroxybiphenyl). (e) The synthesis of ##STR36## The same procedure as in the synthesis (d) of Example 1 was repeated except that 3.6 g of the crude 2,3-difluoro-4,4'-dihydroxybiphenyl obtained in the above-described synthesis (d) were used instead of 4.3 g of 2,2',3,3'-tetrafluoro-4,4'-dihydroxybiphenyl to give 1.0 g (Y., 10.5%) of 4,4'-bis 8(acryloyloxy)octyloxy!-2,3-difluorobiphenyl. m.p.; liquid at room temperature The purity of this material was 99.0% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that the molecular ion peak was observed in 586 by the Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Example 7 (a) The synthesis of ##STR37## The same procedure as in the synthesis (a) of Example 1 was repeated except that 43.9 g of 2-fluoro-4-bromophenol were used instead of 40 g of p-bromophenol to give 46.7 g (Y., 86.4%) of methoxymethy 4-bromo-2-fluorophenyl ether. GC; 97.2% b.p.; 118°-120° C./14 mmHg (b) The synthesis of ##STR38## Into a reactor, 8 g of Mg, and a small number of iodine pieces were charged, to which a solution of 66 g of methoxymethy 4-bromo-2-fluorophenyl ether obtained in the above-described synthesis (a) in 300 ml of THF was added dropwise (if necessary, heated) in a small amount to commence the reaction. Thereafter, the remaining THF solution was added dropwise to the reactor while stirring and refluxing. After the termination of the dropwise addition, the solution was further stirred and refluxed for 4 hours to prepare a Grignard reagent. Into the other reactor, 54 g of (CH 3 O) 3 B and 200 ml of THF were charged, to which the Grignard reagent previously prepared was added dropwise while stirring at a temperature of 0° C. or lower, and gradually heated to room temperature, and thereafter stirred overnight to give a reaction solution. The reaction solution was poured into a dilute sulfuric acid, extracted with an ether, washed with a cold water, dried over sodium sulfate anhydride, and the solvent was evaporated and the residue was immersed into and washed with hexane to give 47.2 g (Y., 84.0%) of 3-fluoro-4-(methoxymethoxy)phenyl boronic acid. HPLC; 88.8% (c) The synthesis of ##STR39## The same procedure as in the synthesis (c) of Example 1 was repeated except that 30 g of 3-fluoro-4-(methoxymethoxy)phenyl boronic acid obtained in the above-described synthesis (b) were used instead of 24 g of 2,3-difluorophenyl boronic acid, and 35.3 g of methoxymethyl 4-bromo-2-fluorophenyl ether obtained in the above-described synthesis (a) were used instead of 33 g of methoxymethyl-4-bromophenylether to give 31.9 g (Y., 68.7%) of 3,3'-difluoro-4,4'-bis(methoxymethoxy)biphenyl. GC; 99% m.p. 76.3°-77.3° C. (d) The synthesis of ##STR40## The same procedure as in the synthesis (d) of Example 1 was repeated except that 24 g of 3,3'-difluoro-4,4'-bis(methoxymethoxy)biphenyl obtained in the above-described synthesis (c) were used instead of 20.1 g of 2,3-difluoro-4'-(methoxymethoxy)biphenyl to give 17.0 g (Y., 98%) of the crude 3,3'-difluoro-4,4'-dihydroxybiphenyl. GC; 99.6% (e) The synthesis of ##STR41## The same procedure as in the synthesis (d) of Example 5 was repeated except that 3.6 g of the crude 3,3'-difluoro-4,4'-dihydroxybiphenyl obtained in the above-described synthesis (d) were used instead of 4.3 g of 2,2',3,3'-tetrafluoro-4,4'-dihydroxybiphenyl to give 0.34 g (Y., 3.6%) of 3,3'-difluoro-4,4'-bis 8-(acryloyloxy) octyloxy!biphenyl. m.p.; 56.1°-57.9° C. The purity of this material was 99.5% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 586 by the Mass analysis, and the types of the starting materials used, the resulting material was identified as the marked material. Example 8 (a) The synthesis of ##STR42## The same procedure as in the synthesis (c) of Example 1 was repeated except that 32.7 g of 2,3-difluoro-4-(methoxymethoxy)phenyl boronic acid obtained in the synthesis (b) of Example 6 were used instead of 24 g of 2,3-difluorophenyl boronic acid, and 35.7 g of methoxymethyl 4-bromo-2-fluorophenyl ether obtained in the synthesis (a) of Example 7 were used instead of 33 g of methoxymethyl 4-bromophenyl ether to give 20.5 g (Y., 50%) of 2,3,3'-trifluoro-4,4'-bis(methoxymethoxy)biphenyl. GC; 95% (b) The synthesis of ##STR43## The same procedure as in the synthesis (d) of Example 1 was repeated up to the distillation step of the solvent except that 21.7 g of 2,3,3'-trifluoro-4,4'-bis(methoxymethoxy)biphenyl obtained in the above-described synthesis (a) were used instead of 20.1 g of 2,3-difluoro-4'-(methoxymethoxy)biphenyl to give 14.7 g of the crude 2,3,3'-trifluoro-4,4'-dihydroxybiphenyl. (c) The synthesis of ##STR44## The same procedure as in the synthesis (d) of Example 5 was repeated except that 3.4 g of the crude 2,3,3'-trifluoro-4,4'-dihydroxybiphenyl obtained in the above-described synthesis (b) were used instead of 4.3 g of 2,2',3,3'-tetrafluoro-4,4'-dihydroxybiphenyl to give 9 g (Y., 90%) of 2,3,3'-trifluoro-4,4'-bis 8-(acryloyloxy)octyloxy!biphenyl. m.p.; liquid at room temperature The purity of this material was 99% measured by HPLC, and 1 spot measured by TLC. Also, according to the results of the IR measurement, the fact that a molecular ion peak was observed in 604 by the Mass analysis, and the types of the starting materials used, the resulting material was identified as a marked material. Examples 9-13 (The liquid crystal display elements using a monofunctional liquid crystal polymeric material) A cell was prepared using 1.1 mm glass substrates having ITO (a mixture of indium oxide and tin oxide; having a thickness of 500 angstrom) transparent electrodes while maintaining a 5 μm gap with a spacer. On one side of the cell thus prepared, the photo-mask 3 was disposed as shown in FIG. 5. Moreover, a uniform mixture of 0.65 g of stearyl acrylate, 0.15 g of 1,4-butanediol acrylate, 0.10 g of styrene, 0.10 g of the polymeric compound X shown in Table 1, 13.3 g of a liquid crystal material, ZLI-4792 (manufactured by Merck, Inc.; Δn=0.094), and 0.04 g of a photoinitiator (Irgacure 651) was injected into the cell by a capillary tube. TABLE 1______________________________________Compound X Value of n Example No.______________________________________ ##STR45## 12 6 4 8 9 10 11 12______________________________________ Then, while impressing a ±4V electric voltage between the transparent electrodes, the cell was irradiated with a parallel light from a high pressure mercury lamp at a rate of 10 mW/cm 2 at 100° C. for 8 minutes (The ultraviolet ray was irradiated to create a spatially regular pattern to the cell). Then, the cell was gradually cooled to 25° C. (at which the liquid crystal was in a nematic state) at a rate of 10° C./hr. while impressing an electric voltage, and further irradiated continuously with the ultraviolet ray for 3 minutes to cure the resin to prepare a liquid crystal display element. When the resulting element was observed by a polarization microscope, it was observed that the liquid crystal regions 20 were formed in the portions corresponding to the photo-mask and that the liquid crystal molecules were spirally oriented around a central axis which was located in the center of the liquid crystal region, as shown in FIG. 6. A polarizing plate was attached to each substrate of the cell so that they were at a right angle to each other. FIG. 7 shows the electrooptical characteristics of the cell obtained in Example 11. The electrooptical characteristics of the cells obtained in other examples (Examples 9, 10, 12 and 13) generally showed the same trend as those shown in FIG. 7. The generation of disclination lines was substantially perfectly controlled in the cells of Examples 9-11, but a few disclination lines were generated in the cells of Examples 12 and 13. The transmittance of the cell of Example 9 in the absence of an electric voltage was significantly reduced as illustrated in Table 2. The higher the number of n in the general formula (I), the larger the transmittance of the cell. TABLE 2______________________________________ Exam- Exam- Exam- Exam- Exam- ple 9 ple 10 ple 11 ple 12 ple 13______________________________________Transmittance in 37 48 51 55 52the absence of anelectric voltage (%)______________________________________ Examples 14-17 (The liquid crystal display elements using a bifunctional liquid crystal polymeric material) On a cell prepared by the same procedure as in Examples 9-13, a photo-mask was disposed in the same manner as in Examples 9-13. Moreover, a uniform mixture of 0.75 g of stearyl acrylate, 0.10 g of styrene, 0.15 g of the polymeric compound Y shown in Table 3, 13.3 g of a liquid crystal material, ZLI-4792 (manufactured by Merck, Inc.; Δn=0.094), and 0.04 g of a photoinitiator (Irgacure 651) was injected into the cell by a capillary tube. TABLE 3______________________________________ ValueCompound Y of n Example No.______________________________________ ##STR46## 12 8 6 13 14 15 ##STR47## 8 16______________________________________ The cell into which the mixture was injected was irradiated with an ultraviolet ray while impressing an electric voltage in the same manner as in Examples 9-13 to prepare a liquid crystal display element. When the element thus prepared was observed by a polarization microscope, it was observed that the liquid crystal regions 20 were formed in the portions corresponding to the photo-mask, that the liquid crystal molecules were spirally oriented around a central axis which was located in the center of the liquid crystal region, end that regions having a smaller amount of twisting were formed in the neighborhood of the liquid crystal regions, as shown in FIG. 4. When a polarizing plate was attached to each substrate of the cell so that they were at a right angle to each other, it was observed that the same viewing angle characteristics as those of Examples 9-13 were obtained. Moreover, when an electric voltage was impressed on the resulting element, the generation of disclination lines was not observed in the element. Table 4 illustrates the electrooptical characteristics of the element thus prepared. TABLE 4______________________________________ Example Example Example Example 14 15 16 17______________________________________Transmittance 36 53 50 52in the absence ofan electic voltage (%)Transmittance 0.9 0.8 0.8 0.6when a voltage of10 V is applied (%)______________________________________ According to Table 4, the cell of Example 17, which was prepared from the fluoridized bifunctional liquid crystal polymer material, has a lower transmittance at the time of impressing an electric voltage, and exhibits excellent display characteristics. This is because (1) the cell of Example 17 provides more double refractions of the remaining liquid crystal materials than the cells of Examples 9-13, and (2) the liquid crystal molecules were not easily dissolved in the polymer film attached on the substrates by using the fluoridized liquid crystal material, thereby reducing an anchoring strength to the surface of the polymer film, as observed with the polarization microscope. Comparative Example 1 On the cell prepared in Example 9, a photo-mask 3 was disposed as shown in FIG. 5. Moreover, a uniform mixture of 0.75 g of stearyl acrylate, 0.15 g of 1,4-butanediol acrylate, 0.10 g of styrene, 13.3 g of a liquid crystal material, ZLI-4792 (manufactured by Merck, Inc.; Δn=0.094), and 0.04 g of a photoinitiator (Irgacure 651) was injected into the cell by a capillary tube. Then, the cell was irradiated with an ultraviolet ray, while impressing an electric voltage in the same manner as in Examples 9-13 to prepare a liquid crystal display element. When an electric voltage was impressed on the element thus prepared, the generation of disclination lines was observed by a polarization microscope. Moreover, the transmittance of the cell at the time of impressing an electric voltage was 2.2%. Since this value was greater than those of the cells of Examples 14-17, it was believed that the increase of the transmittance is due to the generation of disclination lines. Example 18 A polyimide film (AL4552; manufactured by Nihon Synthetic Rubber, Inc.) was applied to 1.1 mm glass substrates having ITO (a mixture of indium oxide and tin oxide; having a thickness of 500 angstrom) transparent electrodes formed by the spin coating method, and subjected to the rubbing treatment with a nylon cloth. These two substrates thus prepared were attached to each other through a 5 μm spacer so that the rubbing directions were at a right angle to each other. On the surface of the cell thus prepared, a photo-mask 3 was disposed as shown in FIG. 5. Moreover, a uniform mixture of 0.55 g of stearyl acrylate, 0.15 g of 1,4-butanediol acrylate, 0.20 g of styrene, 0.10 g of the polymeric compound X used in Example 11, 13.3 g of a liquid crystal material, ZLI-4792 (manufactured by Merck, Inc.; Δn=0.094; the twist angle was adjusted to 90° by using a chiral material;, S811), and 0.04 g of a photoinitiator (Irgacure 651) was injected into the cell by a capillary tube. Then, a TN mode liquid crystal display element having liquid crystal regions surrounded by a polymer wall was prepared by the same procedure as in Examples 9-13. Polarizing plates were attached to both surfaces of the element thus prepared so that the polarization axes of the polarizing plates corresponded to the respective rubbing direction. The liquid crystal of the element thus prepared was in the TN orientation with a uniform orientation state. Moreover, the display characteristics of the element were not varied, even when the outer surface of the element was pressed by a pen. Example 19 A polyimide film (Sunever; manufactured by Nissan Chemical, Inc.) was applied to 1.1 mm glass substrates having ITO (a mixture of indium oxide and tin oxide; having a thickness of 500 angstrom) transparent electrodes formed by the spin coating method, and subjected to the rubbing treatment with a nylon cloth. These two substrates thus prepared were attached to each other through a 9μm spacer so that the rubbing directions were at an angle of 240° to each other. On the surface of the cell thus prepared, a photo-mask 3 was disposed as shown in FIG. 5. Moreover, a uniform mixture of 0.55 g of stearyl acrylate, 0.15 g of 1,4-butanediol acrylate, 0.20 g of styrene, 0.10 g of the polymeric compound X used in Example 11, 13.3 g of a liquid crystal material, ZLI-4427 (manufactured by Merck, Inc.; the twist angle was adjusted to 240° by using a chiral material, S811), and 0.04 g of a photoinitiator (Irgacure 651) was injected into the cell by a capillary tube. Then, a STN mode liquid crystal display element having liquid crystal regions surrounded by a polymer wall was prepared by the same procedure as in Examples 9-13. Polarizing plates were attached to both surfaces of the element thus prepared so that each of the polarization axes of the polarizing plates was at an angle of 45° from the rubbing direction and they were at an angle of 105° to each other. The liquid crystal of the element thus prepared was in the STN orientation with a uniform orientation state. Moreover, the display characteristics of the element were not varied, even when the outer surface of the element was pressed by a pen. Example 20 A polyimide film (Sunever; manufactured by Nissan Chemical, Inc.) was applied to 1.1 mm glass substrates having ITO (a mixture of indium oxide and tin oxide; having a thickness of 500 angstrom) transparent electrodes formed by the spin coating method, and subjected to the rubbing treatment with a nylon cloth. These two substrates thus prepared were attached to each other through a 2 μm spacer so that the rubbing directions were at a right angle to each other. On the surface of the cell thus prepared, a photo-mask 3 was disposed as shown in FIG. 5. Moreover, a uniform mixture of 0.02 g of polyethyleneglycol diacrylate (NK-ester A-200; manufactured by Shin-Nakamura Chemical Industries, Inc.), 0.09 g of lauryl acrylate, 0.01 g of styrene, 0.08 g of the polymeric compound X used in Example 11, 0.80 g of a liquid crystal material, ZLI-4003 (manufactured by Merck, Inc.), and 0.005 g of a photoinitiator (Irgacure 651) was injected into the cell by a capillary tube. Then, a FLC mode (SSF type orientation) liquid crystal display element having liquid crystal regions surrounded by a polymer wall was prepared by the same procedure as in Examples 9-13. Polarizing plates were attached to both surfaces of the element thus prepared so that the polarization axes of the polarizing plates were at an angle of 90° to each other. The liquid crystal of the element thus prepared was in the SSF orientation with a uniform orientation state. Moreover, the display characteristics of the element were not varied, even when the outer surface of the element was pressed by a pen. Moreover, no disturbance of the orientation which was generated in ordinary FLC mode elements occured when the surface of the element was pressed. Various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be broadly construed.	The polymeric compound of this invention is represented by the following general formula (I): ##STR1## wherein A represents a hydrogen atom or ##STR2## B represents a hydrogen atom or ##STR3## each of X 1 and X 2 represents independently a hydrogen atom or a methyl group, each of m and n represents independently an integer of 0 to 14, each of p and q represents independently 0 or 1, and each of Y1 , Y 2 , Y 3 , and Y 4 represents independently a hydrogen atom or a fluorine atom, with the proviso that both A and B are not hydrogen atoms, p is 0 when m is 0, and q is 0 when n is 0. The liquid crystal display element of this invention includes a pair of substrates oppositely disposed with a gap therebetween, and a liquid crystal layer placed in said gap, at least one of said substrates being transparent, and said liquid crystal layer having a liquid crystal region, and a polymer wall surrounded by said liquid crystal region, wherein said liquid crystal layer includes a liquid crystal material, a polymeric polymer material, and the above-described polymeric compound. The liquid crystal display element prepared from the polymeric compound of this invention does not cause disclination lines, and has bright characteristics in the absence of an electric voltage.	2
FIELD OF THE INVENTION The invention relates to apparatus for the continuous mixing and wetting of solids, especially wood chips and fibers, with liquids, especially liquid glue. BACKGROUND OF THE INVENTION Known mixing apparatus of the kind to which this invention relates is described, for example, in U.S. Pat. No. 3,734,471 and includes a mixing trough or drum having suitable inlet and outlet funnels for admitting and discharging, respectively, the materials to be mixed and wetted. The materials are agitated by a coaxial motor-driven mixing shaft or stirrer equipped with radial arms that cause a generally axial advance of the material through the trough in the form of a ring which retains contact with the wall of the trough. Located in the outlet funnel is a pivoted and counterweighted throttle valve. The degree of opening of the throttle flap depends on the pressure exerted by mixing stock on the pivoted throttle flap. The distance of the counterweight from the pivotal axis of the throttle flap is adjustable, making possible an initial adaptation of the machine to certain anticipated operating conditions, e.g. to the kind of chips to be used and the like. Another embodiment of the mixing apparatus, described in U.S. Pat. No. 3,734,471 provides for control of the throttle flap by an electromagnet, actuated in dependence on the power consumption of the drive motor for the mixing shaft, so that the opening/closure position of the throttle, which is constant for a given motor load, can be varied as the current consumption fluctuates. The known apparatus is not capable of reliably maintaining the motor load, i.e. the electrical power consumption, constant as the operating conditions of the mixer change. OBJECT OF THE INVENTION It is, accordingly, an object of the present invention to overcome the deficiencies of a mixer of the above-described kind in such a manner that the load imposed on the drive motor can be maintained constant. This object is attained, according to the invention, by providing a mixing apparatus with a mixing trough having an inlet and an outlet and an outlet throttle valve. According to the invention, the counterweight for the pivotable throttle can be moved by a motor to adjust the valve to different operating conditions of the mixer. Thus, the possibility of opening the throttle in correspondence to the pressure of the stock in the mixing container is augmented by varying the closure force for each position of the throttle flap. In this way, an operator might displace the counterweight toward the pivotal axis of the throttle flap when he observes an increase of the current consumption of the drive motor, so that the closure pressure of the throttle flap as a whole decreases, or vice versa. In a fully automatic configuration, the motor serving to position the counterweight then becomes the positioning, or final control element of control circuitry to maintain constant the current, power consumption of the drive motor of the mixing shaft. In this way, it is possible to eliminate shutdowns due to motor overload. Furthermore, the entire quality of glue deposition upon the chips can be improved by the precise regulation now possible, because even short-term fluctuations of the operating conditions, for example, fluctuations in the density of the chip mixture or the like, can be compensated. In a particularly advantageous embodiment of the invention, the counterweight is the final control element of a control loop which holds the electrical load of the drive motor of the mixing stirrer constant. An advantageous feature of the invention provides that the counterweight is constituted by the housing of the motor which moves the counterweight. Further advantages and features of the invention will be more apparent from the following detailed description of sample embodiments taken in conjunction with the drawing. THE DRAWING FIG. 1 shows a mixer according to the invention in axial section; FIG. 2 is a section through the mixer along the section line II--II in FIG. 1; FIG. 3 is a partial section of FIG. 2 showing a variant of the counterweight; FIG. 4 shows a control circuit for the exemplary embodiment according to FIG. 2; and FIG. 5 shows a control circuit for the exemplary embodiment according to FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS The mixer illustrated in the drawing has a cylindrical mixing container 1 consisting of an inner trough 2 forming its inner wall of a cooling jacket 3 surrounding the inner trough. The mixing container 1 is closed at its ends by bulkheads 4, 5. A material inlet funnel 6 is provided at one end--the right end in FIG. 1--of the mixing container 1. The funnel 6 with its mixing stock inlet opening 7 tangentially enters the inner chamber 1' of the mixing container 1 enclosed by the inner trough 2 and the bulkheads 4 and 5. A likewise tangential material outlet funnel 8 is located at the other end--the left end in FIG. 1. The mixing container 1 is divided into halves in the horizontal plane, the upper half 9 and the lower half 10 of the mixing container 1 being mutually pivotable at one longitudinal side by hinges 11 and are held together at the opposite longitudinal side by releasable fasteners 12. A coaxial mixer shaft 13 is disposed within the mixing container 1. The shaft 13 is supported by bearings 14, 15 and is rotated by a motor 16 with the aid of V-belt 17 and a V-belt pully 18 nonrotatably attached to the shaft 13 which also carries balancing discs 19, 20. A cooling water supply tube 21 is located within the mixer shaft 13 and rotates with the shaft 13. Threaded sleeves 22 are attached to the mixer shaft 13 and hollow mixing tools 23 can be screwed into the sleeves 22. A cooling water supply tube 24 branches off into each hollow mixing tool 23 from the cooling water supply tube 21, so that the cooling water flows through the cooling water supply tube 21, continuing through the cooling water tubes 24, through the inner chamber of each of the mixing tools 23, and into the annular chamber between the cooling water supply tube 21 and the interior of the mixer shaft 13. The cooling water reaches the mixer shaft 13 via a cooling water connection 25--provided at the left in FIG. 1--in which the cooling water supply is designated "a" and the cooling water discharge is designated "b". A glue supply tube 26 extends into the hollow mixer shaft 13 at the other end of the mixer 13--at the right in FIG. 1. The tube 26 does not rotate with the shaft 13. Glue flows from the glue supply tube 26 through inlet openings 27 into the interior of the hollow mixer shaft 13, and is flung outwardly by glue sling tubes 28. The tubes 28 have outlet openings 29 which dip into the ring of material 30 that has built up on the inner wall of the mixer container 1 due to the centrifugal force which results when the shaft speed exceeds a certain critical value. A separator 31 is disposed in the hollow mixer shaft 13 between the mutually neighboring ends of the cooling water supply tube 21 and the glue supply tube 26. The region of the container 1, over which the mixing stock inlet funnel 6 with the opening 7 extends in the longitudinal direction of the container 1, forms an entry zone A for the material. The material to be mixed, e.g. wood chips, is strongly accelerated radially within this entry zone A by the shovel-like feed tools 32 and forms the above-mentioned material ring 30. The longitudinal region of the mixing container 1 adjoining the entry zone A forms a glue admission zone B containing the glue-dispensing tubes 28 attached to the hollow mixer shaft 13. The next adjoining region containing the cooled mixing tools 23 disposed on the mixer shaft 13 is a post-mixing zone C. The mixing container 1 is supported by the bearings 14, 15 on a machine understructure 33 resting on the floor 34. The introduction of glue through the hollow mixer shaft, is sometimes referred to as internal glue application. It is also possible to use external glue application through glue admission tubes which penetrate the cooling jacket 3 and the inner trough 2 in the same mixer container section B; these tubes and their outlets likewise terminate in the material 30. Such a configuration is described, for example, in the W. German laid-open application No. 2219 352. An outlet opening 35 enters the outlet funnel 8 from the inner chamber 1' of the mixing container 1. This outlet opening 35 is closable in per se known manner by means of a throttle flap 36 fitted to the curvature of the inner trough 2 in the region of the outlet opening 35. The throttle flap 36 is pivoted at its upper and axially parallel edge by means of a joint 37 on the container 1, and can be pivoted downwardly and sideways to the right in FIG. 2 from the closed position shown in FIG. 2 in direction of the arrow 38. The outlet opening 35 is thus opened more or less depending on the prevailing pressure, and the rotating mixing tools 23 fling the material out through the variably opened outlet opening 35 into the outlet funnel 8. A bracket 40 is attached to the outside of the throttle flap 36, and a guide rod 41 is rigidly affixed to the bracket 40 and extends outwardly approximately horizontally when the throttle flap 36 is closed. The stator housing 43 of a commercially available motor 44 is displaceably supported on the guide rod 41 by means of a guide bushing 42. The spindle 45 of the motor 44 is freely pivotable on the bracket 40, so that the guide rod 41 and the spindle 45 are mutually parallel. When the spindle motor 44 is actuated, its stator housing 43 is displaced axially on the guide rod 41 because the spindle 45 is attached to the bracket 40. This displacement changes the lever arm of the housing 43 of the stator motor 44 relative to the pivotal axis of the throttle flap 36 formed by the joint 37. It is possible to provide a double-acting hydraulic cylinder 46 instead of the motor 44; the piston rod 47 of such a hydraulic cylinder would be pivotably attached to the bracket 40 while the cylinder 48 is displaced on the guide rod 41 by a guide sleeve 42. The two pressure fluid inlet and outlet lines 49, 50 are only suggested in FIG. 3. The control apparatus for this outlet throttle includes a current transformer 52 that produces a voltage which is proportional to the current flowing through the motor 16 and is inserted in the circuit 51 of the motor 16. The proportional voltage is rectified in a bridge rectifier 53. The DC voltage signal is then transmitted to a controller 54, where it is converted to a corresponding current in a resistor 55. This current is a direct current proportional to the current consumption of the motor. A potentiometer 56 serving as the demand value or reference value source is connected in parallel with the resistor 55. The output of the potentiometer 56 is connected to the output of the resistor 55, and the current coming from the demand value source and from the resistor 55 are added together at a junction point 57. A negative current is always supplied by the demand value source, whereas a positive current is being supplied by the resistor 55. An operational amplifier 58 follows the junction point 57, and applies a corresponding signal to a power amplifier 59 following the controller 54, according to whether a positive or a negative current difference is brought to the operational amplifier from the junction point 57. The spindle motor 44 is then energized by the power amplifier 59, displacing the stator housing 43 of the motor 44 along the guide rod 41 until such time as the current consumption of the motor 16 once again agrees with the demand (reference) value programmed by the potentiometer 56. In hydraulic embodiments illustrated in FIGS. 3 and 5, a magnetic valve is actuated by the power amplifier 59. The magnetic valve switches the hydraulic supply between the fluid lines 49 and 50, one of these lines serving as a return line. In all other respects the remaining circuit is the same as already described. It would also be possible to provide a counterweight that could be displaced on a guide rod by a motor coupled to the counterweight but otherwise stationary and attached to the throttle flap 36. In such an arrangement, it would be particularly appropriate to dispose the motor axially parallel with the joints 37, so that a bevel gear would suitably be provided between the motor and the counterweight. The foregoing description relates to merely preferred exemplary embodiments of the invention. Other embodiments, variants and suitable changes may be made by those skilled in the art without departing from the spirit and scope of the invention.	An apparatus for mixing solid particles and a liquid, especially wood chips and glue. A motor-driven stirrer in a cylinderical trough continuously mixes the materials which enter at one end of the trough and are discharged at the other end. The outlet of the trough has a pivotable throttle with a counterweight which controls the degree of opening of the throttle. An electrical signal related to the load on the stirrer motor is the control signal for a control loop whose final control element displaces the counterweight to maintain the electrical load of the drive motor approximately constant.	1
CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 14/159,339, filed Jan. 20, 2014, which is a continuation of U.S. patent application Ser. No. 13/572,493 filed Aug. 10, 2012, and issued as U.S. Pat. No. 8,635,202 on Jan. 21, 2014, which is a continuation of U.S. patent application Ser. No. 13/284,717 filed Oct. 28, 2011, and issued as U.S. Pat. No. 8,244,709 on Aug. 14, 2012, which is a continuation of U.S. patent application Ser. No. 12/751,679 filed Mar. 31, 2010, and issued as U.S. Pat. No. 8,051,064 on Nov. 11, 2011, which is a continuation of U.S. patent application Ser. No. 09/539,167, filed Mar. 29, 2000, and issued as U.S. Pat. No. 7,720,833 on May 18, 2010, which claims the benefit of U.S. Provisional Application Ser. No. 60/179,645 filed Feb. 2, 2000, all of which applications are incorporated herein by reference in their entireties. TECHNICAL FIELD The present invention relates to the retrieval of information over a network and more particularly to a change detection and notification system. BACKGROUND As networks and computers have been able to deliver information faster, users have begun to expect instantaneous information and information available from anywhere in the world. The vast amount of information available has created an overload of information for the user. Internet search tools and search engines allow users to find information by searching for keywords throughout an index of millions of documents posted on websites. However, a problem with the search engines is the inability to receive updated information on specific pages. A user may frequently access the information on web pages to see if changes have occurred, but this is time consuming. Accessing information is tedious, particularly when information contained in a large database and large searches must be conducted. Software tools have been developed to automate the task of detecting updates to information on web pages and within databases. These tools allow users to specify keywords which are periodically searched for in a news database. Some of these tools send news articles containing the specified keywords to the user by electronic mail (e-mail). These automated software tools are sometimes known as “netbots”, a network robot which automatically performs some task for a user. Netbots allow the users to manage the information within databases and reduce the amount of information that the user must read. Filtering of the information is critical to making good use of the overwhelming amount of information available to the user. Change detection tools allow users to register a document or web page on the Internet and be notified when any change to that document occurs. The user registers a document by specifying the URL of the document and providing the user's e-mail address. The change detection tool stores a local copy of the document together with the user's e-mail address. Periodically (for example daily or weekly), the change detection tool access the source document specified by the URL and compares the retrieved source document to the local saved copy of the document. If a difference between the two copies is detected, a message is sent to the user's e-mail address notifying the user of the change in the document. These document change tools may store an actual copy of the entire document on the tools website for comparison. However, such tools are inefficient for retrieving updated information within a database, for example, an auction site. Because of the large amount of data within these sites, a user may be notified too often or with too much information for the updates to be useful. Often the user is notified of many insignificant changes and frequent e-mail notices of minor irrelevant changes become irritating to the user. In addition, such URL reminders notify the user only that a change has taken place and do not highlight the changes or indicate the changes to the user. Thus, the user must re-read the entire document to determine what has changed. BRIEF DESCRIPTION OF THE DRAWINGS Features and advantages will be apparent to one skilled in the art in light of the following detailed description in which: FIG. 1 is an illustration of one embodiment for a distributed auction site, search updating system; FIG. 2 is a block diagram of one embodiment of an architecture of a computer system; FIG. 3A is a block diagram of one embodiment for a random access memory, such as that shown in FIG. 2 ; FIG. 3B is a block diagram of one embodiment of search criteria used in the system of FIG. 1 ; FIG. 4A is a block diagram of one embodiment for an auction site, search updating system; FIG. 4B is a block diagram of one embodiment of search results; FIG. 5 is a flow diagram of one embodiment for automatically updating auction site searches; FIG. 6 illustrates an exemplary personal shopper user log-in window; FIG. 7 illustrates an exemplary saved search results window; FIG. 8 illustrates an exemplary existing search and modification window; FIG. 9 illustrates an exemplary search criteria preview and save window; FIG. 10 illustrates an exemplary search modified verification window; FIG. 11 illustrates an exemplary window existing search deletion window; FIG. 12 illustrates art exemplary new search recorded verification window; FIG. 13A illustrates an exemplary search results window; and FIG. 13B illustrates the exemplary search results window. DETAILED DESCRIPTION A method, apparatus, and system for automatically updating searches are described. In one embodiment, a first search result may be compared with a second search result to automatically identify at least one data item within the first search result that is changed relative to the second search result. The at least one data item may comprise a transaction term. A notification of the at least one data item may be transmitted to a user device. Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. Although the search update system is described in terms of an auction site, the system and method may be used to automatically update searches of any database. Some portions of the detailed description that follows are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory in the form of a computer program. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. FIG. 1 is a diagram of one embodiment for a distributed auction site, search updating system 100 . Referring to FIG. 1 , server 102 is coupled to mass storage device 104 . Server 102 and mass storage device 104 are coupled via wide area network (WAN) 112 to a variety of clients 106 and 108 . Wide area network 112 may be coupled to any of a variety of clients 106 and 108 . In one embodiment, mass storage device 104 contains an auction item database, a modified or new item database, a search criteria database, and a search results database. In an alternate embodiment, each of the databases may be contained in a separate mass storage devices 104 . A user accesses a server through client 106 , 108 via wide area network 112 in order to enter items for sale in the auction item database, modify items for sale, and enter search criteria for searching for items within the auction item database. After the user enters all the information into the system 100 , server 102 uses the search criteria to search for items within the auction item database. The search results are stored in the search results database and the user is notified that the search is complete. In one embodiment, the user is notified by an e-mail sent from server 102 via wide area network 112 to client 106 , 108 . FIG. 2 is a block diagram of one embodiment for an architecture for a computer system 200 . Referring to FIG. 2 , CPU 202 is coupled via bus 215 to a variety of memory structures and input/output 210 . The memory structures may include, for example, read only memory (ROM) 204 , random access memory (RAM) 206 , and/or non-volatile memory 208 . In one embodiment, CPU 202 is also coupled via bus 215 to network interface 212 . Network interface 212 is used to communicate between computer system 200 and server 102 and a variety of other computer terminals 108 . Network interface 212 is coupled to the wide area network 112 by any of a variety of means such as, for example, a telephone connection via modem, a DSL line, or the like. The architecture shown in FIG. 2 may be utilized for either client 106 , 108 , server 102 , or both. FIG. 3A is a block diagram of one embodiment for random access memory (RAM) 206 . Referring to FIG. 3A , RAM 206 contains auction item application 302 , search criteria application 304 , search engine 312 , and change-detection manager 310 . Change-detection manager 310 includes update responder 306 and update detector 308 . Auction item application 302 is used to add or modify items to the item database. Auction item application 302 interacts with the user via a graphical user interface (GUI) to set up items for sale. Search criteria application 304 is used to add, modify and delete search criteria for searching the item database. Search criteria application 304 interacts with the user via a GUI to set up criteria for searching the item database. Search engine 312 searches the item database using the search criteria entered through search criteria application 304 . Update responder 306 handles communication between server 102 and the search engine software. Update detector 308 is responsible for performing the automatic update of the searches. In one embodiment, change-detection manager 310 is the NetMind Change-Detection tool provided by NetMind Services, Inc. of Campbell, Calif. FIG. 3B is a block diagram for one embodiment of search criteria 320 used in system 100 . Referring to FIG. 3B , search criteria 320 may include a unique search ID 322 , a user identification 324 , user e-mail address 326 , category indicator 328 , search string 330 , search frequency 332 , minimum bidding price 334 , maximum bidding price 336 , search includes description 338 , order of the search results 340 , search starting date 342 , and search ending date 344 . The entries in search criteria 320 are entered through a GUI. Search ID 322 is a unique identifier for the search criteria 320 . In one embodiment, search ID 322 is automatically generated by system 100 when the search is saved. User ID 324 is a unique identifier for the user and is entered by the user when the user signs-up for the notification service. User e-mail address 326 is used to notify the user of the results of the updated search results. Category search 328 indicates the auction site category for the search. In one embodiment, the user may search items for sale based upon the item category (for example, autos, boats, or the like). Search string 320 contains the search data entered by the user for the search (for example, “BMW 3225i”). Search frequency 332 indicates how often a search update is performed. For example, search frequency 332 may indicate a daily, weekly, or monthly update. Minimum bidding price 334 contains the lowest bid price entered by the user for the item and maximum bidding price 336 contains the highest bid price entered by the user. Search includes description 338 is a tag that indicates whether the search is to be performed on the description of the item in addition to the title of the item. Order of search results 340 indicates whether the search results are displayed newest first or oldest first. Search starting date 342 indicates the date from which the search updates are performed. In one embodiment, search starting date 342 is automatically inserted by the system when the user saves the search information. Search ending date 344 indicates the date at which the search updates are to be concluded. FIG. 4A is a block diagram of one embodiment of an auction site, search updating system 400 . Referring to FIG. 4A , items processor 405 accesses item database 410 to add items to item database 410 . Items are entered by a user through a GUI. Items processor 405 extracts new or modified items from item database 410 and places the extracted items in modified or new items database 415 . The extraction of modified or new items is performed on a regular basis. For example, the extraction may be run on an hourly or nightly basis. Search criteria input processor 425 downloads search criteria 320 into search criteria database 420 . Search criteria 320 is input into the system 400 by the user through a GUI. In one embodiment, the user is queried at the time a search is initially entered into the system whether the user wishes to save the search for future updates. If the user does not wish to save the search, the search is performed on the item database 410 and the results displayed to the user. However, if the user wishes to save the search, search criteria input processor 425 performs an initial search against auction item database 410 and displays the search results on the user's terminal. In addition, search criteria input processor 425 saves search criteria 320 entered by the user in search criteria database 420 . Update notification engine 430 uses search criteria 320 from search criteria database 420 to search the modified or new items database 415 to create search results. The search results are stored in search result database 440 . Update notification engine 430 compares search results on a periodic basis. The periodic basis is determined by search frequency 332 . Thus, search criteria 320 may indicate that the search is performed and the comparison made on an hourly, nightly, or weekly basis. Update notification engine 430 runs the current search and compares the search results for the current search with search results from a prior run stored in search results database 440 . Update notification engine 430 retrieves search criteria 320 from search criteria database 420 . Search criteria 320 is used to search the modified or new items database 415 and the results are transferred to update manager 310 . Update detector 308 parses the new search results. In one embodiment, the search results are sorted in date order with the latest date first. Update detector 308 retrieves the previously stored search results from search result database 440 to make the comparison. In one embodiment, each auction item extracted from new or modified items database 415 is tagged with a beginning and ending tag. During the parsing, each result is divided into sections based upon the tags and the new search results are parsed and divided depending on the tags. In one embodiment, each tag section is then processed by a CRC generator to checksum each section. After all sections of the search results have been checksummed, the archived checksummed sections in search result database 440 for the corresponding search are compared to the current checksummed sections. If a match is found, then a section has not changed. However, if no match is found, then that particular auction item has changed. The changed items are saved in mail notification 435 . After all comparisons have been made, the newest checksummed search results are saved in search result database 440 replacing the previous search results for the particular search. FIG. 4B is a block diagram of one embodiment of the search results 450 . Each search result 450 contains a search ID 452 and a number of search result entries 454 . Each search result entry 454 contains an item tag 456 , checksum entry 458 , and change tag 460 . Search ID 452 corresponds to search ID 332 . Item tags 456 are unique identification tags to each individual auction item contained within database 410 . Checksums 458 are the checksum values generated by update detector 308 and change tags 460 are temporary data areas used by update detector 308 to determine if a change has occurred. In one embodiment, the change codes are initialized to 11 before processing. Any entries 454 whose change code remains 11 at the end of processing are new sections or changed sections. Change tags 460 keep track of type of change found. A change code is written into the change tags 460 for each entry 454 when a match is found or not found. In one embodiment, when a match is found, change tag 460 is set to 00 indicating that no change occurred in this section. After all archived sections in search result 450 have been compared, if all change tags 460 are 00, then no new sections or changes were found. However, entries 454 with change tags 460 other than 00 indicate that a change has occurred. The results of the comparison are sent to the user via e-mail notification 435 . In one embodiment, the notification is by an e-mail message sent from server 102 to client 106 , 108 . In alternate embodiments, any applicable notification system may be utilized such as, for example, notification by web page, by facsimile, or by pager. In one embodiment, the e-mail message contains the changed auction items retrieved from auction item database 410 or new and modified item database 415 . In one embodiment, an e-mail notification is sent for each item that has been found to have changed. In an alternate embodiment, a single e-mail notification 435 will be sent out for each search criteria. E-mail may include not only the item found to have been new or changed, but also the unique search ID 322 , user ID 324 , the category based on the category searched 328 , the search from search string 330 , the frequency 332 , minimum or maximum bidding prices 334 , 336 , whether the search included the description 338 , the starting date 342 , and ending date 344 . In alternate embodiments, additional information may be also sent in the e-mail notification 435 . In one embodiment, update notification engine 430 retrieves searches from modified or new items database 415 on a daily basis. Update notification engine 430 executes the searches for each user for each search. In one embodiment, a user may save up to three searches at any one time. In alternate embodiments, any number of searches may be saved. A search may be active or inactive depending on search criteria 320 . Whether a search is active for a particular execution is dependent upon the duration of a search and frequency 332 entered by the user. If update notification engine 430 finds a match for the search and the comparison shows that a change has occurred from a prior search, the results are sent to the user. In one embodiment, each search result is sent in a separate e-mail notification 435 . If a search is not found or there has been no update since the prior search, update notification engine 430 sends notification message 435 to the user indicating that no match was found. In one embodiment, an e-mail notification 435 is sent only after a specific period of time to indicate that no matches have been found. For example, in one embodiment, if update notification engine 430 does not find an updated match for a week, a “still looking” message is sent to the user. Update notification engine 430 also sends a notification 435 to the user that a search will expire. In one embodiment, the update notification engine 430 sends the expiration notice to the user 24 hours prior to the expiration of the search. FIG. 5 is a flow diagram of one embodiment for automatically updating auction site 100 searches. Initially at processing block 505 , new and modified items for sale are extracted from item database 410 and placed into modified or new items database 415 . In one embodiment, the extraction is performed on a periodic basis, for example, hourly or nightly. In addition, search criteria 320 are extracted from search criteria database 420 . In one embodiment, search criteria 320 are extracted for each user and each user may have up to three search criteria. At processing block 510 , modified or new items database 415 is searched using the extracted search criteria 320 from search criteria database 420 . Search results are saved in search results database 440 . Any known searching method may be used to search the database. At processing block 515 , the search results for the new search are compared to the search results from a previous search. If any items have changed or are new, the particular items are tagged. Update notification engine 430 uses search criteria 320 from search criteria database 420 to search the modified or new items database 415 to create search results. The search results are stored in search result database 440 . Update notification engine 430 compares search results on a periodic basis. The periodic basis is determined by search frequency 332 . Thus, search criteria 320 may indicate that the search is performed and the comparison made on an hourly, nightly, or weekly basis. Update notification engine 430 runs the current search and compares the search results for the current search with search results from a prior run stored in search results database 440 . At processing block 520 , the results of a comparison are sent to the user by e-mail notification. The results of the comparison are sent to the user via e-mail notification 435 . In one embodiment, the notification is by an e-mail message sent from server 102 to client 106 , 108 . In alternate embodiments, any applicable notification system may be utilized. In one embodiment, the e-mail message contains the changed auction items retrieved from auction item database 410 or new and modified item database 415 . In one embodiment, an e-mail notification is sent for each item that has been found to have changed. In an alternate embodiment, a single e-mail notification 435 will be sent out for each search criteria. E-mail may include not only the item found to have been new or changed, but also the unique search ID 322 , user ID 324 , the category based on the category searched 328 , the search from search string 330 , the frequency 332 , minimum or maximum bidding prices 334 , 336 , whether the search included the description 338 , the starting date 342 , and ending date 344 . In alternate embodiments, additional information may be also sent in the e-mail notification 435 . In alternate embodiments, any appropriate notification method may be used. FIG. 6 illustrates an exemplary personal shopper user log-in window 600 . Referring to FIG. 6 , log-in window 600 includes user ID input area 602 , password input area 604 , and a remember me check box 610 . In one embodiment, when a user signs onto the auction site and enters the search area, the user is presented with the user log-in screen 600 . In an alternate embodiment, log-in window 600 may be displayed when a user enters a search string in any window in system 100 . The user has the option of performing a one time search by entering a search criteria or search string in search string input area 606 and by checking the search titles and description check box 608 . In one embodiment, the user may also create a personal shopper log-in by entering or creating a user ID and password in the appropriate areas 602 , 604 . The user may only save search criteria by creating a personal shopper log-in account. FIG. 7 illustrates an exemplary saved search results window 700 . Saved search results window 700 includes search string input area 702 , search titles and description checkbox 704 , and saved searches 706 . In one embodiment, a user is allowed to save up to three searches at any given time. In an alternate embodiment, the user may save any number of searches. Saved search results 706 include the name of the search and the search status (that is, whether the search is active and the date at which it will end). In addition, saved searches 706 include save search actions 708 that the user may perform on the saved searches 706 . For example, the user may search using the saved search, modify the saved search or delete the saved search. FIG. 8 illustrates an exemplary existing search and modification window 800 . Referring to FIG. 8 , window 800 includes search modification dialog box 802 . Search modification dialog box 802 includes search string input area 804 , search item title or search item title and description check boxes 806 , minimum price range input area 808 , maximum price input area 810 , notification frequency input area 812 , and e-mail notification duration input area 814 . In addition, window 800 includes a preview button 816 for previewing the search and an undo button 818 for undoing the input into dialog box 802 . Dialog box 802 may be used for modification of existing searches or for the input of new searches. Information entered into dialog box 802 is saved in search criteria 320 . FIG. 9 illustrates an exemplary search criteria preview and save window 900 . Referring to FIG. 9 , search criteria 320 entered by the user within dialog box 802 is displayed in search criteria area 902 . Window 900 also includes save button 904 for saving the search results into search criteria 320 and search results received from a search of database 415 in search results area 906 . In one embodiment, the search results shown in search results area 906 show the first four items of items found in database 410 . In an alternate embodiment, any number of search results may be shown in area 906 . Once the user saves the search by pressing save button 904 , the information entered in dialog box 802 is saved in search criteria 320 . The unique search ID 322 is generated for the search and the user identification (entered through user log-in window 600 ) is saved in user ID 324 . User identification may be a combination of the user name and user password entered in log-in window of FIG. 6 . Information entered in input area 804 is saved in search string 330 . If a category had been chosen for the search, the category name will be placed in category search 328 , the price range is placed in the minimum bidding and maximum bidding price 334 and 336 , the frequency is entered into search frequency 332 , an indication whether the search includes a description from 806 is placed into 338 , and the starting date 342 and ending date 344 is generated from the e-mail duration. In one embodiment, starting date 342 is the date the search is entered or modified and ending date 344 is generated based upon the duration and starting date 342 . FIG. 10 illustrates an exemplary search modified verification window 1000 . Referring to FIG. 10 , window 1000 includes an add a new search button 1002 and a view existing searches button 1004 . After save button 904 has been entered, window 1000 is presented to the user for verification of the save operation to either save another search or modify a saved search. FIG. 11 illustrates an exemplary window existing search deletion window 1100 . Referring to FIG. 11 , a user may indicate that a search is to be deleted by entering the delete button in existing search actions area 708 . After the user clicks or enters the delete action, window 1100 is displayed. Window 1100 includes the search to be deleted at 1102 and a delete button 1104 . A user may delete the displayed search by clicking on the delete button 1104 . FIG. 12 illustrates an exemplary new search recorded verification window 1200 . Referring to FIG. 12 , verification window 1200 includes an add a new search button 1202 and a view existing search button 1204 . Verification window 1200 may be displayed after the user has entered a new search in search dialog blocks 802 or through the search string input area 702 of any of the display screens of system 100 . FIG. 13A and FIG. 13B illustrate an exemplary search results window 1300 . Referring to FIG. 13A and FIG. 13B , search results window 1300 is displayed whenever the user searches on an existing search or enters a search string in a search string input area 702 . Window 1300 includes search string input area 1304 , e-mail notification and update access area 1306 , and other search criteria information 1308 . In addition, window 1300 includes search results area 1310 . Items found based upon the search are displayed in search result area 1310 . In one embodiment, the items are displayed beginning with the newest item through the oldest item found. The newest item is based upon the date the item was entered into the auction site or the date that the item was last updated. By clicking on e-mail notification access area 1306 , the user may enter the input of saving searches. If the user has previously signed on, the clicking on 1306 will take the user to the search modification or input window 800 or if the user has not signed on, log-in window 600 will be displayed. By clicking on the e-mail notification access 1306 , the search results displayed in search result area 1310 are saved in search results database 440 . Each item in the search result area 1310 is tagged and a checksum (by the method as described above) is created for the item. The item number and checksum are saved in database 450 . The specific arrangements and methods herein are merely illustrative of the principles of this invention. Numerous modifications in form and detail may be made by those skilled in the art without departing from the true spirit and scope of the invention.	A system, according to some example embodiments, includes a commerce database storing item data for a plurality of items offered for sale. A search criteria database stores search criteria associated with a user, the search criteria including search frequency information indicating frequency of a search update to be performed using the search criteria. A search server operation retrieves the search criteria from the search criteria database and performs an update search of the commerce database, the search being performed using the search criteria and in accordance with the search frequency information. A notification engine operationally identifies an update to a previous search result based on the update search and generates a notification of the update to the previous search result.	6
This is a division of application Ser. No. 413,512, filed Aug. 31, 1982, now U.S. Pat. No. 4,468,182. BACKGROUND OF THE INVENTION This invention relates to the production of atomized metal powder and more particularly to improved apparatus for the production of atomized metal powder in a safer and more efficient manner. The production of atomized powder of metals such as aluminum, magnesium, copper, bronze, zinc and tin and the like carries with it the attendant risk of explosion. Conventionally, therefore, atomized metal powder is produced using a containment or chilling chamber into which the atomized metal stream is injected through an open end of the chamber positioned adjacent the atomizer and a liquid metal reservoir, the atomized metal stream being cooled or chilled with air introduced through the open end by a down stream exhaust fan. Such a system can result in safety hazards because any explosion occurring in the system can propogate backwards to the open ended chiller chamber, often exposing operating personnel to hazardous conditions. Furthermore, the release of resultant burning aluminum particles with intense heat radiation through the open end of the containment vessel upon occurrence of an explosion can also result in further safety hazards. The present invention solves the problems in the prior art by providing a system which contains the gases and burning particles should an explosion occur. SUMMARY OF THE INVENTION An improved apparatus is disclosed for the production of particulate metal comprising a containment vessel having a sidewall extending to an endwall, a source of metal external to the vessel, nozzle means carried by the endwall, the nozzle means including a central bore and providing communication between the vessel and the external source of metal, the sidewall and endwall cooperating with the nozzle means to seal off the interior of the vessel and the metal particles therein from the area adjacent the source of molten metal, a source of atomizing gas flowing through the nozzle means into the vessel, and means for removing depositions in the bore including a source of purging gas directable into the bore. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic flowsheet of the atomized metal product apparatus. FIG. 1A is a vertical cross section of a portion of the apparatus of FIG. 1. FIG. 2 is a side view in section of the containment vessel. FIG. 3 is a side section view of the lower portion of the vessel shown in FIG. 2. FIG. 4 is a fragmentary side section of the apparatus showing one embodiment of the purging mechanism. FIG. 5 is a fragmentary side section of the apparatus showing another embodiment of the purging mechanism. FIG. 6 is a fragmentary side-sectional view of the apparatus showing a third embodiment of the purging mechanism. FIG. 7 is a fragmentary side sectional view showing a method of locking the nozzle and compressed air feed in place. FIG. 8 is an end-section view of FIG. 7 taken along lines VII--VII. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, FIG. 1 illustrates, schematically, the apparatus for producing and handling atomized metal powder from molten metal which may be provided from a molten metal crucible 10 or an ingot 12 which is charged to a holding/melting furnace 20 connected via duct 22 to a reservoir 30 beneath containment vessel 40. One or more atomizing nozzles 32 are mounted to the bottom plate 46 of vessel 40 to provide communication with the molten metal in reservoir 30. The atomized metal produced in vessel 40 is swept out of vessel 40 through duct 88 to primary cyclone separator 90 which passes the coarse particles to powder tank 100 via conveyor 102. Finer particles, including fines, are removed from the air stream in one or more secondary cyclone separators 92 from whence they may be passed to powder tank 100 or separately packaged. The fines may be packaged separately or reblended with the coarser particles. It should be noted in this regard that various classified particle streams emanating from separator 110 may also be blended together in any predetermined amounts or ratios. The atomized powder, preferably kept under an inert gas blanket after separation, is classified at screening station 110 for packaging and distribution in various particle size ranges. Containment vessel 40, as shown in more detail in FIGS. 2 and 3, comprises an outer cylindrical shell 42 terminating at its lower end in a truncated cone 44 to which is mounted bottom plate 46 which carries nozzles 32. Bottom plate 46 seals off the end of cone 44 except for the openings for nozzles. This provides essentially a closed containment vessel or chiller chamber 40, particularly with respect to the area in which the nozzles are mounted. Shell 42 is provided with a open upper end 48 which provides an air entry for the cooling and collecting gases, e.g. air, introduced into containment vessel 40 in accordance with the invention, as will be described below. Still referring to FIG. 2, molten metal reservoir 30 may be mounted below vessel 40 on a platform 36 which may be raised and lowered by mechanism 38 to facilitate changing or servicing nozzle 32. Nozzle 32 is removably mounted to the lower side of bottom plate 46 in a manner to be described which facilitates removal of nozzle 32. Nozzle 32 is provided with a center bore through which flows molten metal to be atomized. The lower end 34 of nozzle 32 is immersed in the molten metal in reservoir 30 when the reservoir is in its raised position as shown in the dotted lines. Air, under pressure, enters nozzle 32 via tube 24 and is emitted adjacent the central bore at the upper end of the nozzle to atomize the molten metal. Atomizer portion of nozzle 32, which forms no part of the present invention, may be constructed in accordance with well known principles of atomization construction such as, for example, shown in Hall U.S. Pat. No. 1,545,253. Tube 24 is detachably connected to a manifold 26 through a quick-disconnect seal fitting 28 (See FIG. 2) to facilitate easy removal of tube 24. Manifold 26 serves to provide an even pressure distribution when a plurality of nozzles are used. Nozzle 32, if used singly, may be coaxially positioned in vessel 40 to permit central current flow of the gases and metal particles. If a plurality of nozzles are used, they may be concentrically mounted about the axis of vessel 40 for the same reason, or for convenience in handling, may be mounted in rows. Concentrically mounted within the lower part of outer cylindrical shell 42 is a second cylinder 52 (FIG. 3) of sufficiently smaller outer diameter to define an annular passageway 50 between cylinders 42 and 52. In FIG. 3, it will be seen that cylinder 52 is provided at its lower end with a conical member 54 which may be welded or fastened at 56 to a ring 58 which may be, in turn, welded or fastened to the end of cylinder 52. Fastened to the lower end of conical member 54 is a ring 60 which is spaced or suspended below the lower end of conical member 54 to provide an opening therebetween. Ring 60 has an outer edge portion 63 which protrudes into the extension of annular passageway 50 defined by the walls of truncated cone 44 and conical member 54. Outer edge portion 63 serves to flow or channel air into vessel 52 for purposes to be explained later. Referring again to FIG. 3, it will be seen that ring 60 may be suspended from truncated member 54 by members 64. Cool air is pulled into vessel 40 by eductor means 400, for example, shown in FIG. 1. The air enters the annular opening 48 (FIG. 2) of outer cylinder 42, passes through filters 70 into annular passageway 50 and into the bottom of vessel 40 adjacent nozzles 32. This cool air, passing through annular passageway 50, at a velocity in the range of about 1000 to 6000 ft/min, serves to keep the inner wall of vessel 40, i.e. the wall of cylinder 52, cool, thereby inhibiting particle deposition thereon. Annular opening 48 is defined by a side shield member 49 and annular ring 51. Side shield member 49 is supported and fastened to annular ring 51a and top member 53, which in turn are secured to vessel 40 to prevent water or other materials being ingested during operation, particularly when this part of the vessel is exposed to the atmosphere. It will be appreciated that during operation, in one embodiment, large volumes of air are ingested through opening 48 for cooling the walls of the chiller chamber of containment vessel 40 and for purposes of carrying the atomized powder out of the vessel. From FIGS. 2 and 3, it will be seen that the annular passageway 50 between inside vessel 52 and outside vessel 42 opens into annular opening 48. It is preferred that outside vessel 42 extends above annular ring 51 to provide a trap 55 for water that may pass through filter 70. Filters 70 may be any conventional filters used for filtering air and are disposed annularly around the periphery of rings 51 and 51a and secured thereto by conventional means. It should be noted that the intake has been shown as spaced apart from both the bottom plate and nozzles to provide an isolation of the air intake from the nozzle and external molten metal to mitigate hazardous conditions. Other structural configurations to accomplish this result can also be used, such as one-way check valves or other labyrinth structures. In another aspect of the invention, it has been found that the temperature of cylinder wall 52 is important. That is, it has been found that if the temperature of the wall is permitted to substantially exceed 300° F., the molten metal, e.g. aluminum, in atomized form has a tendency to stick or become adhered to the cylinder wall in substantial quantities and subsequently break loose, causing unsafe conditions. Accordingly, it has been found, for example with respect to aluminum, that sticking is minimized or is virtually eliminated by lowering the wall temperature of cylinder 52 to preferably less than 250° F. with a typical temperature being less than 225° F. The temperature of the wall of cylinder 52 can be lowered by the collection air introduced at annular opening 48. To provide for cooling of the walls by using collection air, the materials used in construction of the inner cylinder wall 52 should be selected with heat transfer characteristics as well as more conventional corrosion characteristics in mind. For example, it is preferred that materials such as copper, aluminum and stainless steel and the like with or without chrome plating be selected. In yet another embodiment of the invention respecting deposition of atomized particles on the wall of cylinder 52, it is preferred that the roughness of such wall be controlled. That is, the rougher the wall surface is, the greater the tendency is for atomized metal particles, e.g. aluminum, to stick or adhere to the surface. Thus, in one embodiment, the surface should have a roughness of not greater than about 100 to 150 microns RMS and preferably not greater than 60 microns RMS with the finish lines preferably in the direction of flow. As well as providing a controlled surface roughness, it can also be advantageous to prepare or treat the surface with a release agent to further minimize the tendency of atomized particles to stick thereto. Accordingly, it has been found that treating the surface with a release agent selected from the class consisting of waxes and polymeric materials further inhibits the adherence of metal particles thereto. When a wax is used, it has been found that DO-ALL TOOL SAVER, which is available from the DO-ALL Tool Company, provides a finish on the wall of cylinder 52 which is resistant to deposition of atomized aluminum particles when the temperature of the wall is less than 300° F., preferably in the range of about 200° to 250° F. The molten metal in reservoir 30 is initially aspirated therefrom through nozzle 32 by means of the atomizing gas introduced to the nozzle. The atomizing gases, either hot or cold, may be inert gases or other gases. Similarly, the collecting gases may be either hot or cold (but preferably cold), and may be either inert gases or other gases provided with a predetermined amount of layer on the particle surface. This minimizes any oxidizing gases to provide a minimum protective oxidation subsequent oxidation reactions upon exposure to air. Additionally, the collecting gas may be air. The collecting gases used in accordance with the invention may be used to both cool and sweep the metal particles out of containment vessel 40. Because of the flow pattern that develops as the metallic particles are swept upwardly in containment vessel 40, some particles gravitate towards the vessel wall and fall back towards the atomizers. The particles which fall back can interfere with the atomization if they are permitted to accumulate on bottom plate 46 as well as promote unsafe accumulations. Therefore, ring 60 is provided with an outer edge portion 63, as noted above, which protrudes into the portion of the annular passageway 50 between truncated cone 44 and conical member 54. Outer edge portion 63, because it is spaced below conical member 54, redirects and draws in some of the air (e.g. as much as one third of the air being drawn down between the outer and inner vessels to flow into vessel 40) between portion 63 and conical member 54. This redirected air drawn in by outer edge portion 63 sweeps metal particles which fall down the inner vessel wall back into the mainstream of metal powder being swept out of the container. It should be noted that inner portion 63a of ring 60 acts as a deflector for larger particles to aid in sweeping such particles into the main stream. In this way, such metal particles are prevented from accumulating at the bottom of the vessel and interfering with the atomizing process. Inner cylinder 52, which comprises the inner wall of vessel 40, tapers at its upper end into an exit port 78 permitting the metal particles egress to duct 88 which carries them to cyclone separator 90. The upper portion of cylinder 52 may also be provided with one or more pressure relief hatches 72 releasably mounted on and forming a portion of the wall of cylinder 52. Preferably, such hatches, when used, are releasably attached to cylinder wall 52 by a restraining means such as hinge means to inhibit the hatch from blowing away upon a sudden buildup in pressure. While the foregoing description of atomizing apparatus has been made with respect to an updraft vertically mounted vessel, it will be appreciated that the invention has application to horizontally disposed vessels or downdraft vessels. The metal atomizing apparatus of the invention is further characterized by means to facilitate cleaning or removal and replacement of the atomizing nozzle. Such means can be particularly useful if a plurality of nozzles are used in the apparatus and it is desired to either clean out or replace one of the nozzles while continuing to operate the apparatus using the remainder of the nozzles. During operation of the atomizing apparatus, the liquid metal flowing through nozzle 32 can decrease the size of the bore in the nozzle due to metal and metal compounds, e.g. contaminants, collecting on the wall of the nozzle bore. Accordingly, such decrease in bore size can change the particle size obtained during atomization and as a result, it can be difficult to maintain a constant particle size distribution. Thus, it will be appreciated that it is desirable to maintain the nozzle bore in a condition which prevents particle size distribution from changing. While the nozzle may be sealed off and replaced, provision has been made, in accordance with the invention, for in situ purging or cleaning of the nozzle to bring it back to substantially the original bore size. In this aspect of the invention, the nozzles may be purged or cleaned in several different ways. For example, in reference to FIG. 5, there is shown one embodiment of an apparatus which in accordance with the invention permits cleaning or purging of the nozzles. That is, in FIG. 5, there is shown bottom plate 46 having a nozzle 32 projecting therethrough. Nozzle 32 has an upper end 33 which projects into a dished-out portion 37 in plate 46. It will be understood that in operation, an atomizing gas such as compressed air is introduced to nozzle 32 to aspirate and atomize molten metal therethrough while outside air is drawn in through the annular opening 48 to collect or sweep the atomized metal out of the containment vessel. Thus, during the atomizing operation, for purposes of cleaning or purging the nozzle, in this embodiment, both sources of air or gas remain turned on. For purposes of cleaning during operation, there is provided an arm 350 carried in a ball 360 mounted in the wall of the containment vessel which can be operated from outside the vessel. Arm 350 is provided or has fastened thereto a plate or cover 352 which can cover nozzle 32 from the remainder of vessel 40. Thus, for purposes of cleaning, purging plate or cover 352 is placed over nozzle 32 for purposes of redirecting compressed air or gas used for atomization purposes down through the molten metal conduit of the nozzle, thereby cleaning out any material interfering with the flow of molten metal through the nozzle. The redirected gases may be pulsed by momentary applications of the cover over nozzle 32. In another embodiment of this aspect of the invention, there is shown in FIG. 4 a cover which may be utilized for purposes of removing the atomizing nozzles, as noted above. In this embodiment, the air for collecting can remain turned on. However, the compressed air for atomizing should be cut back substantially if it is used to clear the nozzle. Further, in this embodiment, lid 320 is mounted to bottom plate 46 via an arm 322 on lid 320 which is pivotally attached to bracket 324 at 326. Lid 320 is moved between the open and shut positions by shaft 332 which may be activated by an air cylinder 330. Shaft 332 is connected to arm 322 of lid 320 and comprises hinged portions 332a and 332b joined at 332c. Shaft 332 is, in turn, pivotally attached to lid 320 by an arm 340 which is pivotally attached to shaft 332 at 342 and to arm 322 at 344. To open lid 320, shaft 332 and arm 340 are pulley toward cylinder 330 causing arm 322 to rotate about pivot 326 moving lid 320 into an open position as shown by the dotted lines in FIG. 4. This is the normal position for lid 320 during operation of the atomizing process. However, when it is necessary to remove or clean nozzle 32, arm 322 is pushed towards the nozzle to close lid 320 thereby sealing off nozzle 32. This diverts the compressed air used for atomizing, forcing it down the central molten metal conduit of the nozzle and cleans or removes any foreign material in the same way as referred to above. If it is desired to replace a nozzle instead of cleaning, then the compressed air used for atomizing purposes should be turned off in both embodiments described above. Lid 320 in the closed position permits nozzle 32 to be removed or serviced without shutting down the apparatus or creating an undesirable opening into vessel 40 which may upset the air flow balance. While FIGS. 4 and 5 have illustrated the nozzle purging mechanism for a single nozzle for simplicity of illustration, it should be noted that the mechanism finds it greatest utility when used in a multi-nozzle system wherein each nozzle mounted to bottom plate 46 is fitted with such a nozzle purging mechanism. As shown in FIG. 6, the purging can be carried out in another manner with the use of an external source of purging gas via a hose attached to cover 120. In this embodiment, the underside of cover 120 provides a passageway from the hose 180 to the central bore for carrying molten metal in nozzle 32. Cover 120 is moved over nozzle 32, and the pressure of the purging gas is then used to clean undesirable deposits from the bore. In the apparatus shown in FIG. 6, closure 120 is mounted to be slidably movable into a position over nozzle 32. An arm 122 mounted on lid 120 is pivotally mounted at 126 to a shaft 132 of a fluid cylinder 130 which is used to slidably move lid 120 over nozzle 32. Shaft extension 132a, on the opposite end of fluid cylinder 130, may be provided with camming rings or stops 134 and 136 which are used to activate electrical switches 154 and 156. Switch 154, which is activated by stop 134 when fluid cylinder 130 is actuated to close off nozzle 32, controls the flow of purging gas to lid 120, as will be described below. Switch 156 turns on a solenoid valve (not shown) to turn on the flow of atomizing gas to nozzle 32. When shaft 132a on fluid cylinder 130 is in its withdrawn position, i.e. when lid 120 is withdrawn from over nozzle 32, switch 156 is turned on by contact with shoulder 136. Switch 156 may be spring loaded to return to the off postion (see FIG. 6) when not in contact with shoulder 136. This shuts off the flow of atomizing gas when fluid cylinder 130 is actuated to push shaft 132 into its forward position to slide cover 120 over nozzle 32. Referring again to FIG. 6, cover 120 is also connected to a flexible hose 180 via a nipple 182 on cover 120. Flexible hose 180 is connected at its opposite end to a fitting 184 mounted in the wall 42 of vessel 40. Pipe 186 connects fitting 184 with an electrically controlled valve 188 which, when activated (via switch 154), permits purging gas to flow from gas source 200 to cover 120. When fluid cylinder 130 is actuated to slide cover 120 over nozzle 32, shoulder 134 contacts normally off switch 154 turning switch 154 on to open control valve 188 permitting the purging gas to flow into cover 120. Since, concurrently, switch 156 was shut off, thereby shutting off the valve controlling atomizing gas flow to nozzle 32, the purging gas is forced through the central bore for molten metal in nozzle 32, thereby purging the bore. It should be noted that the system, as shown, can provide a steady or pulsated stream of purging gas by manipulation of the cover. Preferably, in the system a short burst of purging gas is used to clear the bore. Such may be provided by a timing mechanism activated by switch 154 to periodically open valve 188 during the time that cover 120 is over nozzle 32. It will be seen that the atomizing gas is turned off. Further, it will be seen that this system may also be used to change nozzles without interfering with the atomizing process. While the purging has been described both with regard to a continuous or pulsated flow, it should be noted that the pulsated flow is the preferred embodiment. Furthermore, if the continuous flow is used, care must be exercised in preventing the nozzle from cooling off, which could result in further coating buildups within the nozzle, thereby defeating the entire purpose of the purging operation. FIGS. 6 and 7 illustrate alternate mechanisms used to mount nozzle 32 and atomizing gas tube 24 to bottom plate 46 of vessel 40 which permits quick disengagement and removal of nozzle 32. In FIG. 7, nozzle 32 is firmly clamped against bottom plate 46 by a clamping mechanism which comprises a clamp 250 on tube 24 with a pin 252. Pin 252 is detachably engaged by a hook 254 on an arm 256 which is connected to a lever 260 at a second pivot point 258. Lever 260 is connected at its fulcrum point 262 to a bracket 270 attached to bottom plate 46. When lever 260 is lowered to the horizontal position shown in the dotted lines, hook 254 can be detached from pin 252 permitting tube 24 and nozzle 32 to be removed as a unit. As mentioned previously, tube 24 slips into quick disconnect fitting 28 which shuts off the flow of atomizing gas when tube 24 is removed, thereby permitting continued operation of the system without loss of atomizing gas. As shown in FIG. 6, there is provided another method of clamping nozzle 32 and tube 24 firmly to plate 46. In this embodiment, an air cylinder 27 urges shaft 27a against pipe 24, thereby securely fixing nozzle 32 against plate 46 for purposes of atomization. It should be noted that, in both embodiments, the underside of plate 46 may be provided with a notch to aid locating and maintaining nozzle 32 in the proper position on plate 46. In accordance with another aspect of the invention, there is provided a novel means for collecting the particle stream. The novel means comprise an eductor or aspirator which provides or creates a suction effect. As shown in FIG. 1, eductor 400 may be mounted to the last cyclone 92 and connected to one or more eductor blowers 410 which sweep an air stream through duct 416 to eductor 400. The air stream exits to the atmosphere from eductor 400 through exit port 420. Within eductor 400 is a Bernoulli tube which attaches to the discharge side of separator 92. As air is pumped through eductor 400, a vacuum is created in the tube which drops the pressure in cyclone 92. This creates a pulling effect in duct 89 which is passed back through cyclone 90 to duct 88 to vessel 40. Cooling air is thereby sucked into vessel 40 through the opening 48 and annular passageway 50 without any fans in the metal particle gas stream. An eductor or aspirator suitable for use in this application may be purchased from the Quick Draft Company. While the system just described utilizes an eductor or aspirator means to create a pulling effect on the system to collect and sweep the atomized particles from vessel 40, it will be understood and deemed to be within the scope of the invention that a pushing system may be used either singly or in combination with the pulling system. For example, fans, or other air-pushing means, such as compressed air or the like, may be connected to opening 48 for purposes of forcing the collecting gases into and through the system. The term "aspirating means" as used herein is defined as pulling collecting gases into the atomizing or cooling chamber without use of mechanical devices, e.g. fans, in the atomized particle stream for drawing the collecting gases and atomized particles through the system. That is, the use of the term "aspirating means" is meant to include means such as devices using Bernoulli tubes, e.g. whereby the collecting gases are drawn through the system. However, it will be understood that devices such as fans or blowers, etc. (external to the atomized particle flow) can be used to force air or gases into Bernoulli tubes and the like for purposes of drawing gases through the atomizing system. It should be further noted, however, that in either of these embodiments, the collecting air is swept through the system without the particles coming in contact with any air-moving means, such as fans or the like. Thereby, the attendant problems with such fans have been successfully avoided in the practice of this invention. It will be further understood that with the eductor system just described, a subatmospheric condition is created adjacent the nozzles on plate 46. However, with the use of a pushing device, as referred to immediately above, a greater than atmospheric condition can be obtained in vessel 40. Thus, it will be understood that a combination of the push and pull systems may be blended in order to get a controlled atmospheric pressure adjacent the nozzles during operation or slightly above or slightly below if it is desired to operate in these areas, depending to some extent on the type of particle desired. When conditions are controlled in the chiller chamber to provide greater than atmospheric pressure, e.g. in the push system, the nozzles can be purged by turning off the atomizing gas to the particular nozzle requiring attention. Then, the pressure in the chamber can be sufficient to purge the nozzle of any undesirable deposits. The production of atomized powder by the apparatus and process of the invention as herein described is thus carried out in a safer and more economical manner. Minor modifications of the herein described embodiments may be apparent to those skilled in the art and is deemed to be within the scope of the invention as defined by the appended claims.	An improved apparatus is disclosed for the production of particulate metal comprising a containment vessel having a sidewall extending to an endwall, a source of metal external to the vessel, nozzle means carried by the endwall, the nozzle means including a central bore and providing communication between the vessel and the external source of metal, the sidewall and endwall cooperating with the nozzle means to seal off the interior of the vessel and the metal particles therein from the area adjacent the source of molten metal, a source of atomizing gas flowing through the nozzle means into the vessel, and means for removing depositions in the bore including a source of purging gas directable into the bore.	1
[0001] The present application is a continuation of application Ser. No. 09/774,435, filed Jan. 30, 2001, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] This invention relates generally to computer systems, and more particularly to methods and associated systems for transferring data between storage systems. DESCRIPTION OF THE BACKGROUND ART [0003] For back-up purposes, data stored in a disk unit of a local mainframe computer system are copied to a remote storage device to prevent data loss in the event of a disaster such as a disk crash or facility shutdown. U.S. Pat. No. 6,098,129 to Fukuzawa et al. (“Fukuzaw”) discloses a configuration for backing-up data from a mainframe computer system (“mainframe”) to an open computer system. Although Fukuzawa discloses the use of low-cost open computer system storage devices for backing-up mainframe data, Fukuzawa does not disclose the use of another mainframe storage device for back-up. [0004] Because mainframes are generally more reliable than other types of computer systems, data stored in the disk unit of a mainframe are ideally backed-up to a disk unit of another mainframe. Remote dual copy functions, which involve the backing-up of stored data from one computer system to another in real-time, have been performed between mainframes using the so-called Count-Key-Data (“CKD”) protocol. The CKD protocol allows currently available mainframes to transfer data at a rate of approximately 17 MB/s (mega-bytes/second). To increase the amount of data that can be copied from one mainframe to another within a period of time, it is desirable to obtain a data transfer rate that is faster than what is currently obtainable using the CKD protocol. SUMMARY OF THE INVENTION [0005] The present invention relates to a method and associated systems for transferring data between mainframe storage devices. While the invention is suitable for remote dual copy functions, the invention may be generally used in applications requiring data transfers. [0006] In one embodiment of the invention, a local disk system of a local mainframe includes one or more local disk units. For back-up purposes, data in at least one of the local disk units are copied to a designated remote disk unit of a remote disk system. Data transfer between the disk units of the local and remote disk systems occurs over a fixed block infrastructure to increase data transfer rates. Accordingly, variable-length data received in the local disk system and destined to be backed-up to the remote disk system are first converted to fixed-length data prior to transmission over the fixed block infrastructure. In the remote disk system, fixed-length data received over the fixed block infrastructure are converted back to variable-length data. [0007] In one embodiment of the invention, a method for performing data transfer between a local disk system and a remote disk system includes the steps of receiving variable-length data in the local disk system, converting the variable-length data to fixed-length data, sending the fixed-length data to the remote disk system, and converting the fixed-length data back to variable-length data in the remote disk system. The use of fixed-length data in the just mentioned method increases the data transfer rate between the local and the remote disk systems. [0008] These and other features and advantages of the present invention will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which includes the accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS [0009] [0009]FIG. 1 shows a schematic diagram of a configuration for performing a remote dual copy function in an embodiment of the present invention. [0010] [0010]FIG. 2 illustrates the format of a track in Count-Key-Data (CKD) format. [0011] [0011]FIG. 3 illustrates the conversion of variable-length data to fixed-length data and vice versa in an embodiment of the present invention. [0012] [0012]FIG. 4 shows a schematic diagram of a configuration for performing a remote dual copy function in another embodiment of the present invention. [0013] [0013]FIG. 5 illustrates the structure of a copy pair information in an embodiment of the present invention. [0014] [0014]FIG. 6 illustrates the structure of a segment control block in an embodiment of the present invention. [0015] [0015]FIGS. 7A and 7B show a method for performing a remote dual copy function in an embodiment of the present invention. [0016] [0016]FIG. 8A shows a schematic diagram of a configuration for performing a remote dual copy function in another embodiment of the present invention. [0017] [0017]FIG. 8B illustrates the structure of a segment control block in another embodiment of the present invention. [0018] [0018]FIGS. 9 and 10 show schematic diagrams of configurations for performing a remote dual copy function in other embodiments of the present invention. [0019] The use of the same reference number in different drawings indicates the same or like components. DETAILED DESCRIPTION OF THE INVENTION [0020] Turning now to FIG. 1, there is shown a schematic diagram of a configuration for performing a remote dual copy function in accordance with an embodiment of the present invention. In a local mainframe 10 A, data provided by a host system 11 A are stored in a disk unit 14 A of a disk system 13 A. Host system 11 A, which is the central processing unit of local mainframe 10 A, conventionally reads from and writes to disk unit 14 A using variable-length data commonly referred to as a“record”. The well known Count-Key-Data (“CKD”) protocol provides a format for representing variable-length data in a mainframe. In this embodiment, host system 11 A provides variable-length data to disk system 13 A via a CKD channel 12 A. [0021] In general, the control software overhead of protocols using variable-length data is higher than that of protocols using fixed-length data (also referred to as “fixed-length blocks or” “fixed blocks”). Thus, variable-length data protocols such as CKD are generally slower than fixed-length data protocols such as the Small Computer Systems Interface (“SCSI”). As a comparison, the data transfer rate of SCSI is 100 MB/s while that of CKD is only 17 MB/S. In the present invention, a fixed block channel 18 (e.g., SCSI channel) is employed to increase the data transfer rate between disk system 13 A and disk system 13 B. As shown in FIG. 1, disk system 13 A includes a conversion function 15 A for converting the variable-length data received from host system 11 A to fixed-length data, which are then transported over channel 18 via a fixed block interface 17 A (e.g., SCSI interface). In remote mainframe 10 B, a fixed block interface 17 B receives the fixed-length data from fixed block interface 17 A. The fixed-length data are provided to disk system 13 B, which includes a disk unit 14 B for storage and a conversion function 15 B for converting the fixed-length data back to variable-length data (and vice versa). [0022] As is well known, a record stored in a disk unit of a mainframe is located by specifying a cylinder number, a head number, a sector number, and a record number. The cylinder number identifies a magnetic disk in the disk unit while the head number identifies a read/write head. The cylinder number and the head number, together, identify a track, which is a circular region on the magnetic disk where individual records are stored. Each track is further divided into fixed-angled regions commonly known as sectors. A sector provides the general location of a record on a track, and thus facilitates the searching of a record. [0023] [0023]FIG. 2 shows the format of a track 51 in CKD format. Track 51 includes a Home Address (“HA”) 200 , gaps 204 , and records R 0 , R 1 , R 2 , etc. HA 200 is located at the beginning of track 51 and contains control information for accessing and identifying the track. As shown in FIG. 2, each field in track 51 is separated by a gap 204 . HA 200 and gaps 204 have fixed lengths. Each record further includes a count field 201 (i.e., 201 A, 201 B . . . ), a key field 202 (i.e., 202 B, . . . ), and a data field 203 (i.e., 203 A, 203 B, . . . ). Count field 201 has a fixed length and contains record control information such as the record number, the length of key field 202 , and the length of data field 203 . Key field 202 includes key information for accessing the user or system data stored in data field 203 . When count field 201 indicates that the length of key field 202 is zero, the record does not include a key field. To locate a record, the record number indicated in count field 201 is checked because the record numbers are not necessarily consecutive. That is, record R 1 does not necessarily follow record R 0 , record R 2 does not necessarily follow record R 1 , and so on. [0024] The conversion of variable-length data to fixed-length data, and vice versa, in accordance with an embodiment of the present invention is now described with reference to FIG. 3. As shown in FIG. 3, the contents of a track can be stored in a predetermined number of fixed-length blocks (i.e., fixed blocks) because the length of a track is fixed. Furthermore, the blocks that are in a sector 205 (i.e., 205 A, 205 B, . . . ) are readily identified because the length of a sector is also fixed. That is, the fixed blocks for a particular sector can be found knowing the position of the sector relative to HA 200 , the number of blocks per sector, and the number of sectors per track. In the example of FIG. 3, the contents of track 51 are stored in fixed blocks 300 A, 300 B, 300 C, etc. Fixed block 300 A is referred to as the“top block” and includes the contents of HA 200 . Thus, the track represented by a set of fixed blocks 300 can be identified by looking up the track number indicated in the HA 200 stored in a fixed block 300 A. The fixed blocks following fixed block 300 A are consecutively arranged to facilitate the conversion of the fixed blocks back into CKD format. That is, fixed block 300 B follows fixed block 300 A, fixed block 300 C follows fixed block 300 B, and so on. Thus, fixed blocks 300 B, 300 C, 300 D, etc. can be consecutively arranged to recreate the CKD formatted data once the matching fixed block 300 A is found. [0025] As can be appreciated by persons of ordinary skill in the art reading the present disclosure, fixed blocks 300 are suitable for transportation using a fixed block protocol such as SCSI. For example, each fixed block 300 can be assigned a unique SCSI logical block address (LBA) because the number of fixed blocks in a track and the number of tracks in a disk unit are fixed. Thus, assuming that each track has 100 fixed blocks, an LBA of 3521 may be used to identify the 22nd block in the 35th track. [0026] [0026]FIG. 4 shows a schematic diagram of a configuration 150 for performing a remote dual copy function in another embodiment of the present invention. As shown in FIG. 4, a local host system 102 , which is the central processing unit of a local mainframe 100 , provides CKD formatted data to a local disk system 104 via a CKD interface 119 A. Local disk system 104 further includes disk units 112 A (i.e., 112 A- 1 , 112 A- 2 . . . ) where data are stored, and a local disk control unit 106 for controlling disk units 112 A. [0027] Local disk control unit 106 includes a cache memory 113 A where data that are in transit or frequently accessed are temporarily stored before being written to a disk unit 112 A. Data in cache memory 113 A are organized in segments (i.e., segments 116 A- 1 , 116 A- 2 , . . . ), with each segment having enough space to hold the entire contents of a single track. [0028] Local disk control unit 106 also includes a mainframe read/write process 108 A for processing disk read and write commands received from local host system 102 , a data send process 109 for sending data to remote mainframe 101 , and a disk unit read/write process 111 A for transferring data between disk units 112 A and cache memory 113 A. In this disclosure, the term “process” includes hardware, software, and/or firmware for performing the indicated function. All of the just mentioned processes can access a shared memory 114 A, which contains multiple copy pair information 117 A (i.e., 117 A- 1 , 117 A- 2 , . . . ) and segment control blocks 118 A (i.e., 118 A- 1 , 118 A- 2 , . . . ). A CKD/FBA conversion function 115 A, which is generally available to all processes of local disk control unit 106 , is called by read/write process 108 A to convert CKD formatted data to fixed blocks and vice versa. In one embodiment, CKD/FBA conversion function 115 A employs the technique described in connection with FIG. 3. [0029] A copy pair information 117 A identifies a disk unit in remote mainframe 101 that is designated as a back-up of a disk unit in local mainframe 100 . FIG. 5 shows the structure of a copy pair information 117 A. Referring to FIG. 5, a local storage system address 400 specifies a local disk system in local mainframe 100 (e.g., local disk system 104 ). A disk unit address 401 specifies a disk unit in the local disk system. Similarly, a remote storage system address 402 and a disk unit address 403 specify a remote disk system in remote mainframe 101 (e.g., remote disk system 105 ) and a disk unit in the remote disk system, respectively. The contents of the disk unit specified in disk unit address 401 are copied to the disk unit specified in disk unit address 403 during a remote dual copy function. [0030] In configuration 150 shown in FIG. 4, each segment control block 118 A contains information relating to a corresponding segment 116 A stored in cache memory 113 A. FIG. 6 shows the structure of a segment control block 118 A in configuration 150 . A disk unit address 500 specifies a disk unit 112 A where storage space is allocated for the segment 116 A. As mentioned, a segment 116 A has enough space to hold the entire contents of the allocated track. If cache memory 113 A is organized in terms of fixed blocks, as is the case in configuration 150 , a segment 116 A has enough space to hold all the fixed blocks of a track. A top block address 501 indicates the top block address of the track for which a segment 116 A is allocated, and can thus be used to locate the segment 116 A. [0031] As shown in FIG. 6, a segment control block 118 A also includes a block bitmap 502 , a remote write bitmap 503 , and a local write bitmap 504 . Each bit of bitmaps 502 , 503 , and 504 corresponds to a block of the segment 116 A identified by top block address 501 . Accordingly, the number of bits of each of the just mentioned bitmaps is equal to the number of blocks in a segment 116 A. Each bit of block bitmap 502 indicates whether the corresponding block is in cache memory 113 A; i.e., when a bit of block bitmap 502 is ON, the block which corresponds to that bit is in a segment 116 A in cache memory 113 A. The bits of remote write bitmap 503 indicate whether the corresponding blocks need to be written to a disk unit in remote disk system 105 . That is, when a bit of remote write bitmap 503 is ON, the block which corresponds to that bit is to be transmitted to remote disk system 105 of remote mainframe 101 . Similarly, each bit of local write bitmap 504 indicates whether the corresponding block needs to be written to a disk unit of local disk system 104 . [0032] Referring to FIG. 4, a fixed block interface 120 A transports fixed blocks to remote mainframe 101 over a fixed block infrastructure 121 . In one embodiment, interface 120 A is a SCSI interface, and infrastructure 121 is a SCSI infrastructure that includes SCSI cables, line drivers, adapters, repeaters, etc. To process the fixed blocks received over infrastructure 121 , remote disk system 105 includes components that mirror those of local disk system 104 . That is, remote disk system 105 also has a data receive process, a mainframe read/write process, a CKD/FBA conversion function, a cache memory, a shared memory, a disk unit read write process, and a CKD interface that are similar to those in remote disk system 105 . In the present disclosure (including in FIG. 4), the same or like components are labeled with the same reference numeral. For example, shared memory 114 A of local disk system 104 is similar to shared memory 114 B of remote disk system 105 . [0033] A method for performing a remote dual copy function in accordance with an embodiment of the present invention is now described with reference to FIG. 7A, FIG. 7B, and FIG. 4. Referring to FIG. 7A, a remote dual copy function is initiated when read/write process 108 A receives a Define Extent command from local host system 102 (step 701 ). As is conventional, the Define Extent command includes information for processing forthcoming Locate and Read/Write commands such as cache memory utilization mode etc. After receiving the Define Extent command, read/write process 108 A then receives a Locate Command (step 702 ). As is conventional, the Locate command specifies a record to access by providing a cylinder number, a head number, a sector number, and a record number. The cylinder number and the head number, together, identify a particular track in a disk unit. To determine if there is a segment 116 A allocated for the track specified in the Locate command, read/write process 108 A checks the top block addresses 501 of the segment control blocks 118 A (step 703 ). Note that read/write process 108 A may utilize CKD/FBA conversion function 115 A to convert CKD formatted data to fixed blocks and vice versa. [0034] If a segment 116 A is allocated for the track, read/write process 108 A checks the block bitmap 502 of the corresponding segment control block 118 A to determine if fixed blocks belonging to the sector specified in the Locate command are in cache memory 113 A (step 704 ). [0035] If the blocks corresponding to the sector number are not in cache memory 113 A or if a segment 116 A is not allocated for the track specified in the Locate Command, a segment 116 A and corresponding segment control block 118 A are created for the track (step 706 ). Thereafter, the contents of the track are loaded from the disk unit 112 A specified in the Locate command to disk unit read/write process 111 A (step 707 ), converted to fixed blocks (step 708 ), and then stored in cache memory 113 A in the allocated segment 116 A (step 709 ). [0036] Once it is established that the contents of the track are in cache memory 113 A, read/write process 108 A finds a record in a disk unit 112 A where write data from a forthcoming Write command is to be written (step 705 ). Subsequently, read/write process 108 A receives the Write command that goes with the previously received Define Extent and Locate commands (step 710 ). Read/write process 108 converts the write data that accompany the write command from CKD format to fixed blocks (step 711 ), stores the converted write data to cache memory (step 712 ), and then sets the corresponding bits in remote write bitmap 503 and local write bitmap 504 (step 713 ). At a later time, disk unit read/write process 111 A conventionally writes the fixed blocks identified in local write bitmap 504 to their respective disk units 112 A. [0037] Continuing with step 714 shown in FIG. 7B, data send process 109 checks the bits of the remote write bitmaps 503 in shared memory 114 A to find the fixed blocks that need to be sent to remote disk system 105 . Data send process 109 uses the information in a copy pair information 117 A to determine the remote disk unit designated to receive the fixed blocks (step 715 ). Data send process 109 sends the fixed blocks to remote disk system 105 via fixed block interface 120 A and over fixed block infrastructure 121 (step 716 ). Because fixed block interface 120 A, fixed block interface 120 B, and infrastructure 121 are based on SCSI in this embodiment, each fixed block is assigned a unique logical block address. [0038] In remote disk system 105 , a data receive process 110 receives the fixed blocks via a fixed block interface 120 B (step 717 ). Data receive process 110 then checks the top block addresses of segment control blocks 118 B to determine if there is a segment 116 B allocated for each received fixed block (step 718 ). If a segment 116 B is not allocated, a segment 116 B and a corresponding segment control block 118 B are created for the fixed block (step 719 ). Data receive process 110 then stores the fixed blocks in their respective segments 116 B (step 720 ). Thereafter, data receive process 110 sets the corresponding bits in the block bitmap and local write bitmap of the segment control block 118 B (step 721 ), and notifies data send process 109 that the fixed blocks have been received and processed in remote disk system 105 (step 723 ). In response, data send process 109 resets the corresponding bits in the remote write bitmap 503 in local disk system 104 . At a later time, disk unit read/write process 111 B in remote disk system 105 conventionally writes the fixed blocks identified in the local write bitmap of the segment control block 118 B to their respective disk units 112 B. [0039] [0039]FIG. 8A shows a schematic diagram of a configuration 250 for performing a remote dual copy function in another embodiment. In contrast to configuration 150 , cache memory 213 (i.e., 213 A, 213 B), segment 216 (i.e., 216 A, 216 B), and segment control block 218 (i.e., 218 A, 218 B) of the mainframes in configuration 250 are configured to process CKD formatted data. That is, each segment 216 of a cache memory 213 has enough space to hold the records of a single track in CKD format. [0040] In configuration 250 , each segment 216 has a corresponding segment control block 218 . FIG. 8B shows the structure of a segment control block 218 in configuration 250 . As shown in FIG. 8B, a disk unit address 800 specifies a disk unit 112 where storage space is allocated for the segment 216 . A track address 801 contains the address of the track allocated for the segment 216 . [0041] A segment control block 218 further includes a record bitmap 802 , a remote write record bitmap 803 , and a local write record bitmap 804 . Each bit of the just mentioned bitmaps corresponds to a record stored in the corresponding segment 216 . Accordingly, the number of bits of each of the just mentioned bitmaps is equal to the maximum number of records in a track. [0042] Record bitmap 802 indicates whether a record is in a segment 216 . When a bit of record bitmap 802 is ON, the record that corresponds to that bit is in a corresponding segment 216 . [0043] Remote write record bitmap 803 indicates whether a record in the corresponding segment 216 needs to be written to a disk unit in the remote disk system (which is identified in a copy pair information 117 similar to that used in configuration 150 ). When a bit in remote write record bitmap 803 is on, the record that corresponds to that bit is transmitted to the remote disk system. [0044] Local write record bitmap 804 indicates whether a record in the corresponding segment 216 needs to be written to a disk unit in the local disk system. When a bit of local write record bitmap 804 is on, the record that corresponds to that bit is written to a disk unit in the local disk system. [0045] In configuration 250 , CKD formatted data from local host system 102 are not converted to fixed blocks until the data are ready to be transmitted to remote disk system 105 . Accordingly, data send process 109 calls CKD/FBA conversion function 115 A to convert the CKD formatted data to fixed blocks before handing the data to fixed block interface 120 A. In remote disk system 105 , data receive process 110 calls CKD/FBA conversion function 115 B to convert the fixed blocks received over fixed block infrastructure 121 back to CKD format. [0046] As is evident from the foregoing, configuration 250 and configuration 150 are similar except for the use of CKD formatted data in the cache memory of configuration 250 . Persons of ordinary skill in the art will appreciate that the present invention can be employed regardless of the cache memory management scheme. For example, FIG. 9 shows a configuration 350 where the local disk system uses a fixed block cache management scheme similar to that used in the local disk system of configuration 150 , whereas the remote disk system uses a CKD cache management scheme similar to that used in the remote disk system of configuration 250 . Similarly, FIG. 10 shows a configuration 450 where the local disk system uses a CKD cache management scheme similar to that used in the local disk system of configuration 250 , whereas the remote disk system uses a fixed block cache management scheme similar to that used in the remote disk system of configuration 150 . [0047] A method and associated systems for transferring data between storage systems for mainframe computers have been disclosed. While specific embodiments have been provided, it is to be understood that these embodiments are for illustration purposes and not limiting. Many additional embodiments will be apparent to persons of ordinary skill in the art reading this disclosure. For example, while the invention is suitable for use in remote dual copy functions, the invention is not so limited and may be generally used in applications requiring data transfer between storage systems. Thus, the present invention is limited only by the following claims.	A local disk system in a local mainframe computer includes one or more local disk units. Data in at least one of the local disk units are backed-up to a designated remote disk unit in a remote disk system. Data transfer between the local disk system and the remote disk system occurs over a fixed block infrastructure to increase data transfer rates. Accordingly, variable-length data received in the local disk system and destined to be backed-up to a remote disk system are first converted to fixed-length data prior to transmission over the fixed block infrastructure. In the remote disk system, fixed-length data received over the fixed block infrastructure are converted back to variable-length format.	6
RELATED CULTIVARS ‘Amor White’ is related to ‘Amor’ (Ser. No. 09/734,607). ‘Amor White’ is a color mutant of ‘Amor’. BACKGROUND OF THE INVENTION ‘Amor White’ is a product of a breeding and selection program that had the objective of finding color mutants of ‘Amor’. The new plant of the present invention comprises a new and distinct cultivar of Chrysanthemum plant that is a natural occurring sport of a parent Chrysanthemum named ‘Amor’. A comparison with parent chrysanthemum ‘Amor’ is also made in this application. The new cultivar was discovered as a sport in September, 1998 by Rob Noodelijk in a controlled environment (greenhouse) in Rijsenhout, Holland. The first act of asexual reproduction of ‘Amor White’ was accomplished when vegetative cuttings were taken from the initial selection in October, 1998 in Rijsenhout, Holland. The new cultivar has been found to retain its distinctive characteristics through successive propagations. BRIEF DESCRIPTION OF THE DRAWINGS The present invention of a new and distinct variety of Chrysanthemum is shown in the accompanying drawings, the color being as nearly true as possible with color photographs of this type. FIG. 1 shows a plant of the cultivar in full bloom. FIG. 2 shows the various stages of bloom of the new cultivar. FIG. 3 shows the various stages of foliage and petiole of the new cultivar. DESCRIPTION OF THE INVENTION This new variety of Chrysanthemum is of the botanical classification Chrysanthemum morifolium. The observations and measurements were gathered from plants grown out door in Rijsenhout, Holland under natural day length and temperature and planted week 22 in 1999 and 2000. The natural blooming date of this crop was September 4-9 (week 36). The average height of the plants was 32-38 cms. No growth retardants were used. No tests were done on disease or insects resistance or susceptibility. No tests were done on cold or drought resistance. This new variety produces medium sized blooms with white ray florets and a yellow center blooming for a period of 7 weeks. When ‘Amor’ and ‘Amor White’ and are being compared the following differences and similarities are noticed: The differences of ‘Amor’ and ‘Amor White’ are (1) Flower color and (2) Vigour. All other characteristics of ‘Amor’ and ‘Amor White’ are similar. (1) Flower color. ‘Amor White’ is a sport of ‘Amor’, bearing white ray-florets instead of pink ray-florets. (2) Vigour: The plants of ‘Amor White’ tend to be a little more vigorous. The following is a description of the plant and characteristics that distinguish ‘Amor White’ as a new and distinct variety. The color designations are taken from the plant itself. Accordingly, any discrepancies between the color designations and the colors depicted in the photographs are due to photographic tolerances. The color chart used in this description is: The Royal Horticultural Society Colour Chart, 1995 edition. Table 1: Botanical Description of Cultivar ‘Amor White’. Bud: Size.— Medium;cross-section 1.2 cm, height 1.0 cm. Outside color.— Yellow 8 D. Involucral bracts.— 2 rows, length 7 mm, width 3 mm. Involucral bracts among disc - florets.— Not present. Involucral bracts color.— Green 138 B. Bloom: Type.— Decorative. Height.— High, 3.0-3.5 cm. Size.— Medium. Fully expanded.— 5.0-5.5 cm. Borne ( number of blooms per branch ).—Upper and lower portion plural blooms per branch (Approx. 5 blooms per branch). Performance on the plant.— 7 weeks. Seeds ( if crossed ).—Produced in small quantities, ovate. Grey-brown 199 A, 1½ mm in length. Fragrance.— Typical chrysanthemum, slight. Color: Center of the flower.— Immature Yellow 8 C. Mature Yellow 8 C. Color of upper surface of the majority of the ray - florets.— White 155D. Color of the lower surface of the majority of the ray - florets.— White 155D. Tonality from distance.— A mounded decorative garden mum with white blooms with a yellow center. Color of the upper surface of the flowers after aging of the plant.— White 155D. Ray florets: Texture.— Upper and under side smooth. Number.— 200-230. Cross - section.— Concave. Longitudinal axis of majority.— Incurved to straight. Length of corolla tube.— Medium, 0.9-1.1 cm. Ray - floret margin.— Entire. Ray - floret length.— 2.5-2.8 cm. Ray - floret width.— 0.4-0.6 cm. Ratio length/width.— High. Shape of tip.— Pointed. Reproductive organs: Stamen.— Not present. Pollen.— Not present. Styles ( present in ray - florets ).—Thin. Style color.— Yellow-green 144 A. Style length.— 4 mm. Stigma color.— Yellow-green 144 A. Stigma width.— 1 mm. Ovaries.— Enclosed in calyx. Plant: Shape.— Grown as a spray-type pot-mum, outdoor mounded and round. Growth habit.— Spreading. Growth rate.— Moderate. Height.— 32-38 cm. Width.— 35-40 cm. Stem color.— Green 138 B. Stem strength.— Strong. Stem brittleness.— Present. Stem anthocyanin coloration.— Absent. Length of lateral branch.— From top to bottom 14-15 cm. Lateral branch color.— Green 138 B. Lateral branch, attachment.— Weak. Branching ( average number of lateral branches ).—Mounding and prolific with 8-10 breaks after pinching. Peduncle length.— 4.0-4.5 cm. Peduncle color.— Green 138 B. Natural season blooming date.— September 4-9. Foliage: Color of mature leaves.— Upper side green 138 A. Under side green 138 B. Color of immature leaves.— Upper side green 138 B. Under side green 138 B. Size.— Small; length 6 cm, width 5 cm. Quantity ( number per lateral branch ).—12-14. Shape.— Oval. Texture upper side.— Glabrous. Texture under side.— Pubescent. Ribs and veins upper side.— Ribs and veins well developed. Venation arrangement.— Palmate. Shape of the margin.— Serrate. Shape of base of sinus between lateral lobes.— Acute. Margin of sinus between lateral lobes.— Diverging. Shape of base.— Asymmetric. Apex.— Mucronate. TABLE 2 Differences with the comparison varieties (when grown under the same conditions) ‘AMOR WHITE’ ‘AMOR’ Color of ray-florets White 155D Red-purple 74C Length of lateral 14-15 cm 12-13 cm branch Plant height 32-28 cm 32-26 cm	A Chrysanthemum plant named ‘Amor White’ characterized by its medium sized blooms with white ray florets and prolific branching; natural season flower date September 4-9; blooming for a period of 7 weeks.	0
FIELD OF THE INVENTION [0001] This invention relates to a method and an apparatus for building and transferring a tread or a tread belt reinforcing structure on a building drum. BACKGROUND OF THE INVENTION [0002] In the manufacture of pneumatic tires elastomeric components, some of which are reinforced by cords of textile or wire, are formed as long strips. These strips are assembled together to form a carcass subassembly in a first stage of assembly. This carcass typically has one or more cord reinforced plies, a pair of bead cores and an air impervious liner. Additional strips of material such as apexes, shoulder gum strips and chippers and chaffers may also be used in this first stage of tire assembly. [0003] In a second stage the tread rubber and belt or breaker reinforcing structure is typically applied to the carcass after the carcass has been toroidally shaped on the tire building drum. The tread rubber can be of one homogeneous compound or more. Typically the tread is a sophisticated composite of many different rubber materials co-extruded to form a tread strip. The belt or breaker reinforcing layers generally include two layers or more of cross plies reinforced by equal but oppositely oriented cords of textiles, such as nylon or aramid or wire such as steel. Additionally, overlays or underlays of generally circumferentially oriented cords may be added as an additional layer. [0004] Tires typically have been built using this two-stage assembly. Once assembled this uncured assembly of the components is placed in a mold to be vulcanized to form a finished tire. [0005] High speed and efficient ways to manufacture tires require the processes to be reliable and fast. Accordingly, manufacturers of tires have experimented with and perfected many ways to improve on the basic two-stage assembly of tires. [0006] One method described in U.S. Pat. No. 3,865,670 taught the use of an expansible and contractible transfer ring for conveying a breaker tread assembly from a building drum in a tire building machine to a tire carcass mounted on a tire shaping machine. [0007] An improved but somewhat similar U.S. Pat. No. 3,888,720 also disclosed a separate tread breaker building drum designed to vary in size to accommodate different sizes of tires. [0008] Similarly, the Charles E. Todd U.S. Pat. No. 3,865,669 also disclosed an expansible and contractible transfer ring for conveying a breaker-tread assembly. [0009] Each of these prior art patents recognized that an assembly of a tread belt to a tire carcass can be accomplished off-line or separate from the carcass building machine. Once formed into a ring these tread breaker assemblies could be moved to encircle a tire carcass, the carcass inflated to contact the inner surface of the tread breaker assembly and then stitched together by a roller mechanism to form a green or uncured tire assembly to be placed into a mold. [0010] While these assembly techniques provided efficiencies in production, none really changed the method for actually forming a tire assembly. [0011] Conventional tire molds, whether two piece molds or segmented molds, form the tread surfaces by pressing groove forming ribs and sipe forming blades into the tread rubber as the tire is molded. As this is done the belt cords, particularly those directly under the groove-forming ribs deflect in small but noticeable undulations. These undulations create a variety of changes across the tread that actually can vary the surface or change the amount of tread rubber across the otherwise normal appearing tire. These non-uniformities can lead to mass imbalance issues, irregular wear and a variety of associated ride and handling performance issues. The goal in tire manufacturing is to minimize unpredictable non-uniformities in manufacturing while also building the tire in a very cost-efficient manner. [0012] The object of the present invention is to provide a method that minimizes or eliminates the influence of the tread forming mold surfaces as the tire is molded. [0013] A further object of the invention is to provide a more productive method of assembling the tread-belt or breaker reinforcing structure to the carcass. [0014] Another objective is to change the method of how the tread forming surfaces engage the tread rubber. [0015] Still another objective is to provide a novel apparatus for forming the tread-belt or breaker assembly and to employ that apparatus to a unique tire building system. SUMMARY OF THE INVENTION [0016] A method of building and transferring a tread on a tread belt reinforcing assembly on a building drum is disclosed. The steps include applying at least one uncured tread component onto a radially collapsible building drum; inserting the at least one uncured tread component and the radially collapsible building drum into an open segmented mold wherein a plurality of tread forming segments are radially expanded; contracting the plurality of tread forming segments pressing into the at least one uncured tread component; collapsing the building drum; and removing the building drum thereby transferring the at least one uncured tread component into the mold. [0017] The method further includes inserting a tire carcass into the mold; closing the mold; expanding the carcass under pressure forcing the carcass into contact with the at least one uncured tread component forming a tire assembly; and curing the assembly. [0018] Preferably, the method provides the additional step of heating the at least one uncured tread component to a temperature above ambient most preferably at 110° C. or more, prior to closing the segments and wherein the at least one uncured tread component is warmed and softened as the segments press into the tread. [0019] The step of applying at least one uncured tread component also can include applying one or more cord reinforced belt, breaker, overlay or underlay layers onto the building drum prior to applying one or more layers or strips of uncured tread rubber to form a tread-belt reinforcing assembly. [0020] The apparatus for building and transferring a tread or tread belt reinforcing assembly has a radially expandable and axially rotatable support means; a drive means for rotating the support means about the axis; a plurality of arcuate or straight segments slidably mounted over the support means, the plurality of arcuate or straight segments forming an annular building surface; a transfer means for removing the plurality of arcuate or straight segments from the support means and wherein the transfer means provides radial support for the plurality of arcuate or straight segments when the support means is contracted. [0021] The apparatus further includes a means for radially expanding and contracting the radially expandable and axially rotatable support means. [0022] The preferred apparatus has a portable radially expandable and axially rotatable support means; a drive means for rotating the support means about the axis, a plurality of arcuate or straight segments slidably mounted over the support means, the plurality of arcuate or straight segments forming an annular building surface; a means for radially expanding and contracting the radially expandable and axially rotatable support means; a means for receiving and accepting the tread or tread belt assembly while mounted on the plurality of arcuate or straight segments mounted onto the portable support means, the receiving means being a segmented mold with radially movable tread forming segments. [0023] The preferred apparatus further has a plurality of arcuate or straight gap spanners interposed between an adjacent pair of arcuate or straight segments and wherein each pair of adjacent arcuate or straight segments has a gap of at least 0.050 in. (1.25 mm) in the radially expanded position, the gap spanners providing a radially outer surface which bridges between and overlaps pairs of adjacent segments. When radially contracted the arcuate or straight segments reduce the circumferential gap and thereby circumferentially reduce the length of the surface supporting the tread or tread belt reinforcing assembly, thereby releasing the tread or tread belt assembly. [0024] The arcuate or straight segments and the overlapping gap spanners when mounted on the support means and fully expanded provide a rigid internal surface that prevents the tread or tread belt assembly from locally distorting as the mold tread forming segments are closed. Once closed the tread rubber is pressed into the tread forming surface securing the tread or tread belt reinforcing assembly. Once secured the arcuate or straight segments of the support means are contracted releasing from the inner surface of the tread or tread belt assembly. After contracting, the entire portable support means with contracted arcuate or straight segments can be removed from the mold while the mold's tread forming segments are in a closed position holding the tread or tread belt assembly. Then the uncured carcass can be placed into the mold and the mold closed and the curing processes can be initiated. [0000] Definitions [0025] “Apex” means an elastomeric filler located radially above the bead and interposed between the plies and the ply turnup. [0026] “Axial” and “axially” means the lines or directions that are parallel to the axis of rotation of the tire. [0027] “Bead” means that part of the tire comprising an annular tensile member wrapped by ply cords and shaped, with or without other reinforcement elements such as flippers, chippers, apexes, toe guards and chafers, to fit the design rim. [0028] “Breaker Structure” refers to at least two annular layers or plies of parallel reinforcement cords oppositely oriented having the same angle or about 5° less than the parallel reinforcing cords in carcass plies, generally about 20° to less than 50° with reference to the equatorial plan of the tire. [0029] “Belt Structure” means at least two annular layers or plies of parallel cords, woven or unwoven, underlying the tread, unanchored to the bead, and having both left and right cord angles in the range from 17° to 27° with respect to the equatorial plane of the tire. [0030] “Carcass” means an unvulcanized laminate of tire ply material and other tire components cut to length suitable for splicing, or already spliced, into a cylindrical or toroidal shape. Additional components may be added to the carcass prior to its being vulcanized to create the molded tire. [0031] “Casing” means the carcass, the belt reinforcement and other components of the tire excluding the tread. [0032] “Chafers” refers to narrow strips of material placed around the outside of the bead to protect cord plies from the riin, distribute flexing above the rim, and to seal the tire. [0033] “Circumferential” means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction. [0034] “Cord” means one of the reinforcement filaments, cables, or strands of which the plies in the tire are comprised. [0035] “Equatorial plane (EP)” means the plane perpendicular to the tire's axis of rotation and passing through the center of its tread. [0036] “Innerliner or liner” means the layer or layers of elastomer or other material that form the inside surface of a tubeless tire and that contain the inflating fluid within the tire. [0037] “Overlay” means one or more layers of parallel cords underlying tread above the belt structure and having cord angles typically 0° to 15° with respect to the equatorial plane of the tire. [0038] “Ply” means a continuous layer of rubber-coated parallel cords. [0039] “Radial” and “radially” mean directions radially toward or away from the axis of rotation of the tire. [0040] “Radial ply tire” means a belted or circumferentially-restricted pneumatic tire in which the ply cords which extend from bead to bead are laid at cord angles between 65°-90° with respect to the equatorial plane of the tire. [0041] “Section height” means the radial distance from the nominal rim diameter to the outer diameter of the tire at its equatorial plane. [0042] “Section width” means the maximum linear distance parallel to the axis of the tire and between the exterior of its sidewalls when and after it has been inflated at normal pressure for 24 hours, but unloaded, excluding elevations of the sidewalls due to labeling, decoration or protective bands. [0043] “Shoulder” means the upper portion of sidewall just below the tread edge. [0044] “Shoulder gum strip” means an elastomeric reinforcement located in the shoulder region of the carcass. [0045] “Sidewall” means that elastomeric portion of a tire between the tread and the bead. [0046] “Subassembly” means an unvulcanized assembly of laminated unreinforced tire components to which a cord reinforced ply or plies and other tire components can be added to form a casing. [0047] “Tread” means a rubber component which when bonded to a tire carcass includes that portion of the tire that come into contact with the road when the tire is normally inflated and under normal load. [0048] “Tread width” means the arc length of the tread surface in the axial direction, that is, in a plane parallel to the axis of rotation of the tire. [0049] “Underlay” means one or more layers of parallel cords underlying the belt structure or at least one layer of the belt structure and having cord angles typically 0° to 15° with respect to the equatorial plane of the tire. BRIEF DESCRIPTION OF THE DRAWINGS [0050] The invention will be described by way of example and with reference to the accompanying drawings in which: [0051] FIG. 1 is a perspective view of the tread or tread belt assembly building drum of the present invention; [0052] FIG. 2 is a cross-sectional view of the tread or tread belt assembly building drum of the present invention; [0053] FIG. 3 is a perspective view of the transfer means engaged in the support means of the building drum; [0054] FIG. 4 is a cross-sectional view of the apparatus taken from FIG. 3 ; [0055] FIG. 5 is a perspective view showing the transfer means with the support means attached thereto and separated from the building drum; [0056] FIG. 6 is a cross sectional view of the apparatus taken from FIG. 5 ; [0057] FIG. 7 is a cross-sectional view of the tread or tread belt assembly building drum attached to the drive means for rotating the drum and illustrating the means for radially expanding and contracting the support means as well as an overload clutch means; [0058] FIG. 8A is a cross-sectional view of the adjacent arcuate or straight segments with a gap spanner shown in the expanded fully open position; [0059] FIG. 8B is the same features illustrated in FIG. 8A but in the fully collapsed contracted position; [0060] FIG. 9 is a perspective view of the building drum assembly showing a tread belt assembly as applied to the support surface; [0061] FIG. 10 is a cross-sectional view of the tread or tread belt assembly mounted on the building drum and being placed into an opened mold; [0062] FIG. 11A is a cross-sectional view of the tread or tread belt assembly mounted on the building drum with the mold being closed onto the assembly; [0063] FIG. 11B is a cross-sectional view of the tread belt assembly in the mold with the building drum collapsed and being removed from the mold; and [0064] FIG. 12 is a cross-sectional view of the mold and tread or tread belt assembly being cured to a carcass assembly mounted on a collapsible building drum assembly. DETAILED DESCRIPTION OF THE INVENTION [0065] With reference to FIG. 1 , a perspective view of the tread or tread belt assembly building drum of the present invention is illustrated. As shown, the building drum 10 has a radially expandable and contractible support means 20 . The support means 20 has a radially outer surface 24 for building a tread or tread belt reinforcing structure onto the surface 24 . The surface has a plurality of arcuate or straight segments 22 which are connected by gap spanner segments 21 around the peripheral surface of the tread building support means. The arcuate or straight segments 22 and gap spanner segments 21 are slidably attached onto the building drum support means 20 . Each arcuate segment 22 has a hole or opening 55 for accepting a plurality of pins located on a transfer means 50 . The pins 54 can be pressed into the openings 55 and provide a means 50 for transferring the arcuate or straight segments and gap spanner segments as an assembly onto and off the support means 20 . [0066] As used herein, each segment 22 and gap spanner segment 21 can have a flat or straight circumferentially or laterally extending surface or, alternatively, an arcuate surface. Hereinafter the segments will be generally referred to as arcuate while it is understood the surface may be straight in either the circumferential direction or the lateral direction. [0067] As illustrated, in FIG. 1 the transfer means 50 has an annular transfer ring 51 and a guide ring 52 . The guide ring 52 is slidably inserted over the pins 54 and the pins 54 are rigidly attached to the transfer ring 51 as shown. On the exterior surface of the transfer means 50 are shown three knobs 53 . [0068] With reference to FIG. 2 , a cross sectional view of the building drum 10 is shown along with the transfer means 50 . The transfer means 50 is shown not engaged to the building drum 10 or to the arcuate or straight segments 22 . The combination of the arcuate or straight segments 22 and the gap spanner segments 21 form a subassembly commonly referred to as the deck. The term “deck” is commonly referred to with a similar meaning as that of the deck of a boat. It is an exterior surface upon which one can stand or build the tread assembly. For purposes of this invention the building surface 24 will commonly be referred to as the deck 24 . This deck 24 which is an assembly of the arcuate or straight segments 22 and the gap spanning segments 21 is slidably mounted over deck segment guides 116 and 117 . Once slid over these guides 116 , 117 a detent assembly called a deck segment locking pin 115 engages and secures the deck 24 to the drum expansion segment 114 as illustrated. To remove the deck assembly 24 from the radially expandable and contractible tread building drum, the transfer means 50 is pushed into the holes 55 wherein the pins 54 engage the deck segment locking pins 115 thereby releasing them when the pins 54 are fully engaged. This is illustrated in FIGS. 3 and 4 . Once engaged the transfer means 50 can be used to slidably remove the deck assembly 24 as shown in FIG. 5 . The pins 54 provide radial support for the deck assembly 24 and hold the assembly 24 in the position as shown for removal. The perspective view of the removed deck assembly 24 provides a better illustration of the deck segment guides 116 and 117 and the drum expansion segment 114 . As shown, the arcuate or straight segments 22 have the deck segment locking pin 115 engaged by the pin 54 . A spring 129 is used in the contracted position when the pin 54 is inserted as shown in FIG. 6 . Once the pin 54 is removed the spring 129 is free to release and allow the locking pin 115 to extend radially inwardly to accomplish the locking of the mechanism. This is as illustrated in the cross-sectional view of FIG. 6 . [0069] In order for the tread belt building drum 10 to expand radially and contract radially and to provide a surface 24 upon which a tread belt assembly can be built, the building drum 10 must accept a drive means 30 that provides rotational movement of the entire building drum assembly 10 as shown in FIG. 7 . The drive means 30 is connected to a motor (not illustrated) which can provide rotational movement of the tire building drum assembly 10 . The drive means 30 includes a drive spline 100 which is connected to a screw drive shaft 101 and which is embedded inside a drum quick-mount mounting cone 102 as illustrated. The quick-mount mounting cone 102 provides for rapid engagement and disengagement of the drum assembly 10 . The drum quick-mount mounting cone 102 has a key 104 with a key locating pin 103 as illustrated and a longitudinally extending keyway 105 as illustrated. A drum inboard housing 106 is illustrated on the left-hand side of FIG. 7 and a corresponding drum outboard housing 107 is on the right-hand side of FIG. 7 . On the opposite side of the drive means 20 and the drum assembly 10 is an outboard support cone 108 . The outboard support cone 108 has a live center receptacle 109 . The live center permits easy rotation of the drum assembly 10 while the entire assembly is being rotated. Looking internally at the center of the mechanism or apparatus 10 there is a ball screw or acme threaded screw assembly 110 . As illustrated the threaded assembly 110 is comprised of two components, one having left-hand threads and an opposite side having right-hand threads. These two components are pinned together to provide simultaneous rotation of the mechanism. On the left-hand side is an inboard ball nut or acme nut 111 connected to one end of the threaded screw 110 and on the opposite or outboard side another ball nut or acme nut 112 is illustrated. A ball screw overload protection clutch mechanism is illustrated at 113 . This mechanism 113 provides capability of disengaging the shaft 110 and permitting the drum assembly 10 to collapse if the pressure is exceeded beyond the capability of the clutch 113 . This override clutch protection system 113 ensures that when the mold closes or pressure is applied to the radially outer surface of the deck 24 , the deck 24 can collapse as the clutch 113 disengages, permitting the entire unit or drum 10 to collapse slightly preventing any overload from damaging the internal workings of either the mold or the mechanism 10 . Radially directly inward of the deck 24 or its arcuate or straight segments 22 there is illustrated a drum expansion segment 114 . The drum expansion segments 114 are threadedly engaged by threaded fasteners 125 to an expanding segment base 123 as illustrated. They are also located by pins 122 as shown. Radially inward of the expanding segment base 114 is an outward outboard segment cone bushing 121 and an inboard segment cone bushing 120 which are threadedly attached using screws or threaded fasteners 126 as illustrated to the expanding segment base 123 . Radially inward of the inboard segment bushing 120 is the inboard expansion cone 118 . Similarly, on the outboard side the outboard segment cone bushing 121 is radially outward of an outboard expansion cone 119 . The bushings 120 and 121 are designed to slide along the cone surfaces of the inboard expansion cone 118 and outboard expansion cone 119 , respectively. As shown, the building drum 10 is in an expanded position such that the radially outer deck or building surface 24 is radially expanded. As the drive shaft 101 is spun or rotated inside the bearings 127 , 128 the inboard ball nut 111 and outboard ball nut 112 push the expansion cones both inboard and outboard 118 and 119 , respectively, radially to the center plane of the building drum 10 . As these cones 118 , 119 push to the center plane, the conical surface permits the expanding segment base 123 and its bushings 120 and 119 to slide along the conical surfaces and contract radially inwardly. [0070] With reference to FIG. 8A in the fully expanded position the arcuate or straight segments 22 are shown with a gap G between each segment in the fully radially expanded position. The gap G is preferably at least 0.050 in (1.25 mm) as measured between the adjacent segments. The gap spanning segment 21 is constrained in channels 25 . Each gap spanning segment 21 has lobes 26 that are captured within these channels 25 . They may be slid laterally to remove the segments 21 , 22 but are constrained such that the arcuate or straight segments 22 can move circumferentially a certain extent until they engage the lobes 26 as illustrated. This permits a diametrical expansion of the assembly 10 by a few millimeters. The ends of the segments 22 have a chamfered surface 27 which provides a space for the gap spanning segment to occupy at the correct diameter for tread belt building. Upon contraction, as shown in FIG. 8B , the arcuate or straight segments close upon each other and the gap spanning segments 21 are moved within the channels 25 such that the lobes 26 contact the interior surface of the arcuate or straight segments as illustrated in FIG. 8B . When this occurs the gap G between the adjacent arcuate or straight segments 22 is closed permitting each of the segments 22 to contract radially inwardly. This feature enables one to build a tread or tread belt assembly in such a manner that the tread or tread belt assembly can easily be removed once assembled to the deck assembly 24 . This will be discussed later in detail. [0071] With reference to FIG. 9 , the tread drum assembly 10 is shown wherein a typical tread belt reinforcing structure 14 is shown assembled to the exterior surface or peripheral surface of the deck 24 . As shown, a first belt layer 16 is illustrated lying adjacent to the surface 24 . At the lateral edges of the first belt layer 16 are two belt edge elastomeric strips 17 . Interposed in between the elastomeric strips 17 is a second belt layer 15 having cords oriented oppositely relative to the first belt layer 16 . Optionally, and as illustrated, an overlay 18 is shown. The overlay 18 is a circumferentially extended cord reinforced structure that overlays both the second belt layer 15 and the first belt layer 16 and the underlying gum strips 17 . Radially outward of the overlay 18 is an unvulcanized layer 12 of tread rubber. As illustrated the tread rubber 12 may be provided as strips of rubber wound and laid adjacently or can be provided as a single layer. [0072] With reference to FIG. 10 , once the tread belt assembly 14 is applied onto the building surface 24 , the entire building drum assembly can be placed inside a mold 2 . In the illustrated embodiment, the tread assembly 14 is shown mounted on a building drum 10 that is in a radially expanded position and placed inside the open and expanded mold 2 . The mold 2 has tread forming segments 4 on each side, a bottom plate 6 , a pair of bead forming rings 11 and 9 , a top plate 8 , and a tread forming segment 5 attached to the top plate 8 . Once inserted inside the mold 2 , as shown in FIG. 11A , the mold 2 is closed and in the particular embodiment illustrated the mold segments contract against the tread belt assembly on the tread belt drum assembly 10 . In this methodology the tread rubber 12 is then forced into the tread forming grooves of the segments 4 . Once fully contracted the tread rubber 12 would adhere to the tread forming segments 4 . As illustrated it is preferred that the tread rubber 12 be warmed or applied to the building drum 10 hot, such that when the mold closed, the rubber is relatively softened so that it will easily accept, adapt and conform to the tread forming segments 4 . It is believed that the tread 12 should be warmed to a temperature of approximately 110° C., preferably between 90° C. and 110° C. Once the pressure is applied as shown, assuming the pressure does not exceed the desired limits, the entire tread belt assembly 14 will be adequately adhered to the internal surfaces of the tread forming segments 4 . While the mold 2 is still closed, it is desirable then to contract the tread belt drum assembly 10 into a radially contracted position. The tread belt 14 will remain in the tread forming segments 4 . Once fully retracted the drum 10 is freed from the tread belt assembly 14 and the top plate of the mold 8 can be removed along with the associated connected components as was illustrated in FIG. 10 . Once the mold top plate 8 is removed, the tread drum assembly 10 can be removed from the mold 2 . Once removed the tread belt 14 is left in the mold 2 with the segments 4 closed and a tire building drum assembly 7 with a green carcass 72 already mounted to it can be placed into the mold 2 . As shown in FIG. 12 the carcass building drum assembly 7 has an axle 70 that is contoured and locked into the mold using locking detents 74 . Once closed a gaseous fluid or steam is introduced into the interior through the axle 70 and the internal pressure is applied to the carcass adhering it to the tread belt assembly at the interfacial surfaces. The tire is then cured in this self-locking mold 2 as illustrated in FIG. 12 . [0073] When a mold 2 is first closed and the tread building drum assembly 10 is inside the mold, should the mold be misaligned or the tread rubber 12 not properly aligned for closing the segments 4 , then the clutch mechanism 113 will disengage allowing the entire assembly 10 to collapse, thereby preventing damage to the mold 2 as previously discussed. [0074] The present invention permits the assembly of the tread belt assembly 14 to be made on the building drum 10 and as illustrated and the building drum 10 being portably movable permits the entire assembly to be placed inside a mold whereby the tread belt assembly 14 can be transferred directly to the mold 2 prior to being applied to the carcass 72 . Then the tread building drum assembly 10 can be collapsed and removed from the mold 2 and the entire green carcass 72 on a building drum assembly 7 can be inserted into the mold 2 , locked into position, pressurized and cured to form a finished tire. [0075] This method for molding tires is described in a self-locking and copending patent application entitled “The Method For Curing Tires and a Self-Locking Tire Mold”, U.S. patent Ser. No. 10/417,849, filed on Apr. 17, 2003, which is incorporated herein by reference in its entirety. The core building drum assembly 7 for mounting the carcass directly onto is described in U.S. patent application Ser. No. 10/388,733, filed Mar. 14, 2003 and is entitled “Radially Expansible Tire Assembly Drum and Method for Forming Tires”, the contents of which are incorporated herein by reference in its entirety also. [0076] In an alternative method of practicing the invention, the tread 12 or tread belt assembly 14 can be applied to the deck 24 when the deck 24 is set at an outside diameter less than the diameter required to fit precisely in the closed mold position. Typically a small amount of at least 0.5 mm less than the desired finish diameter of the tread belt 14 is selected. In this method of assembly, once the tread 12 or tread belt assembly 14 is placed in the open mold 2 and after the mold 2 is closed and the mold segments 4 are contracted embedding into the tread rubber 12 , then the drive means 30 can be rotated, expanding the building drum 10 from the slightly smaller build diameter to the precise mold diameter required. This additional expansion firmly compresses the tread 12 or tread belt assembly 14 into the mold tread forming segments 4 and insures a slight tensioning of the tread 12 or tread belt assembly 14 into the mold tread forming segments 4 and insures a slight tensioning of the tread 12 or tread belt assembly 14 . Then the deck 24 can be retracted releasing it from the tread 12 or tread belt assembly 14 as previously discussed.	A method of building and transferring a tread 12 or a tread belt reinforcing assembly 14 on a building drum 10 is disclosed. The steps include applying at least one uncured tread component 12, 14 onto a radially collapsible building drum 10 , inserting the at least one uncured tread component 12 and the radially collapsible building drum 10 into an open segmented mold 2 wherein a plurality of mold tread forming segments 4 are radially expanded; contracting the plurality of mold tread forming segments 4 pressing into the at least one uncured tread component 12, 14 ; collapsing the building drum 10 ; and removing the building drum 10 thereby transferring the at least one uncured tread component 12, 14 into the mold. The preferred building drum apparatus 10 has a portable radially expandable and axially rotatable support means 20 ; a drive means 30 for rotating the support means 20 about the axis, a plurality of arcuate or straight segments 22 slidably mounted over the support means, the plurality of arcuate or straight segments 22 forming an annular building surface 24 ; a means 40 for radially expanding and contracting the radially expandable and axially rotatable support means; a means for receiving and accepting the tread or tread belt assembly while mounted on the plurality of arcuate or straight segments 22 mounted onto the portable support means 20 , the receiving means 2 being a segmented mold 2 with radially movable tread forming segments 4.	1
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority of Taiwanese Application No. 093129021, filed on Sep. 24, 2004. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to a lens assembly, more particularly to a miniaturized lens assembly. [0004] 2. Description of the Related Art [0005] Referring to FIGS. 1, 2 and 3 , a conventional lens assembly includes a shell unit 1 , a lens unit 2 received in the shell unit 1 , and a motor 3 for actuating the lens unit 2 . [0006] The shell unit 1 has a peripheral wall 101 and a guiding groove 102 in the peripheral wall 101 . [0007] The lens unit 2 has a front lens portion 4 , a rear lens portion 5 opposite to the front lens portion 4 along a longitudinal axis (X), a large diaphragm plate 6 mounted between the front lens portion 4 and the rear lens portion 5 , a small diaphragm plate 7 mounted pivotally between the front lens portion 4 and the rear lens portion 5 and rotatable relative to the large diaphragm plate 6 , a shutter plate 8 mounted pivotally between the front lens portion 4 and the rear lens portion 5 and rotatable relative to the large diaphragm plate 6 , a connecting member 9 mounted pivotally on the shell unit 1 and connected to the shutter plate 8 , and an electromagnetic actuator 901 mounted on the shell unit 1 for actuating the connecting member 9 . [0008] The large diaphragm plate 6 has a large aperture 601 along the longitudinal axis (X). The small diaphragm plate 7 has a coupling end portion 701 movably anchored in the guiding groove 102 of the shell unit 1 , and a small aperture 702 for overlapping or moving away from the large aperture 601 . The shutter plate 8 has an actuated portion 801 and a shading portion 802 for covering or moving away from the large aperture 601 . The connecting member 9 is mounted outside the front lens portion 4 , and has a pivoting portion 902 , an actuated end portion 903 extending from the pivoting portion 902 and actuated by the electromagnetic actuator 901 , and a transmitting end portion 904 opposite to the actuated end portion 903 and coupled to the actuated portion 801 . [0009] When the motor 3 is actuated to move the lens unit 2 along the longitudinal axis (X), the switching between the large and small apertures 601 , 702 can be achieved through the action of the coupling end portion 701 in the guiding groove 102 . As shown in FIGS. 2 and 4 , when the actuated end portion 903 of the connecting member 9 is actuated by the electromagnetic actuator 901 , the actuated portion 801 of the shutter plate 8 can be actuated by the transmitting end portion 904 so that the shading portion 802 of the shutter plate 8 can be moved relative to the large aperture 601 to shade or move away from the latter so as to achieve the purpose of controlling the shutter plate 8 . [0010] Although the switching between the large and small apertures 601 , 702 and the control of the shutter plate 8 can be achieved in the aforesaid conventional lens assembly, the following disadvantages are encountered: [0011] 1. Since the shutter plate 8 is controlled by the pivotal movement of the connecting member 9 actuated by the electromagnetic actuator 901 , the volume occupied thereby is relatively large. [0012] 2. Since the switching between the large and small apertures 601 , 702 is conducted by the cooperation of the small diaphragm plate 7 and the guiding groove 102 of the shell unit 1 , and since the control of the shutter plate 8 is actuated by the pivotal movement of the connecting member 9 , testing of the lens unit 2 is conducted after the lens unit 2 is installed on the shell unit 1 . If the lens unit 2 needs to be modified or adjusted after the test, it is required to disassemble the same from the shell unit 1 . Therefore, the process for making the conventional lens assembly is troublesome. [0013] 3. The transmitting end portion 904 of the connecting member 9 should have a length sufficient for the operation of the lens unit 2 , and should be inserted between the front and rear lens portions 4 , 5 in order to connect to the actuated portion 801 of the shutter plate 8 interposed between the front and rear lens portions 4 , 5 . Therefore, the installation of the conventional lens assembly is relatively complicated. [0014] 4. The accuracy of the action of the shutter plate 8 may be affected by the accumulated tolerance of the amount of the magnetic affinity of the electromagnetic actuator 901 , the clearance between the transmitting end portion 904 of the connecting member 9 and the shutter plate 8 , the clearance between the pivoting portion 902 of the connecting member 9 and the shell unit 1 , and the like. SUMMARY OF THE INVENTION [0015] The object of the present invention is to provide a miniaturized lens assembly which is simple in structure, which is miniature in size, and which is relatively easy to assemble and convenient to test. [0016] Therefore, a miniaturized lens assembly according to this invention includes a lens unit, which has a front lens portion, a rear lens portion opposite to the front lens portion, a large diaphragm plate mounted between the front lens portion and the rear lens portion, a small diaphragm plate mounted pivotally between the front lens portion and the rear lens portion and rotatable relative to the large diaphragm plate, a shutter plate mounted pivotally between the front lens portion and the rear lens portion and rotatable relative to the large diaphragm plate, first and second actuating elements mounted on the rear lens portion, and two pivot axles mounted between the front and rear lens portions and distal from each other. The large diaphragm plate has a large aperture. The small diaphragm plate has a first pivot portion pivotally connected to one of the pivotal axles, a swing portion opposite to the first pivot portion, a first actuated portion proximate to the first pivot portion, and a small aperture provided in the swing portion. The first actuated portion is actuated by the first actuating element to move the small diaphragm plate between a first position in which the small aperture is aligned with the large aperture, and a second position in which the small aperture is moved away from the large aperture. The shutter plate has a second pivot portion pivotally connected to the other of the pivot axles, a shading portion opposite to the second pivot portion, and a second actuated portion proximate to the second pivot portion. The second actuated portion is actuated by the second actuating element to move the shutter plate between an open position in which the shading portion is away from the large aperture, and a closed position in which the shading portion covers the large aperture. The first and second actuating elements respectively have actuating portions connected to the first and second actuated portions, respectively. BRIEF DESCRIPTION OF THE DRAWINGS [0017] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: [0018] FIG. 1 is a perspective view of a conventional lens assembly; [0019] FIG. 2 is a top view of the conventional lens assembly; [0020] FIG. 3 is a sectional view taken along line 3 - 3 of FIG. 2 ; [0021] FIG. 4 is another top view of the conventional lens assembly showing the movement of a shutter plate of the conventional lens assembly; [0022] FIG. 5 is an exploded perspective view of the preferred embodiment of a miniaturized lens assembly according to this invention; [0023] FIG. 6 is a sectional view of the preferred embodiment; [0024] FIG. 7 is a schematic view showing a state in which a small diaphragm plate and a large diaphragm plate of the preferred embodiment are aligned with each other; [0025] FIG. 8 is a schematic view showing a state in which the small diaphragm plate and the large diaphragm plate of the preferred embodiment are moved away from each other; [0026] FIG. 9 is a schematic view showing a state in which a shutter plate of the preferred embodiment is moved away from the large diaphragm plate; and [0027] FIG. 10 is a schematic view showing a state in which the shutter plate covers the large diaphragm plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0028] Referring to FIGS. 5 and 6 , the preferred embodiment of the miniaturized lens assembly according to this invention includes a shell unit 100 , a lens unit 200 mounted in the shell unit 100 , and a motor 300 mounted on the shell unit 100 for actuating the lens unit 200 . As the configuration for connecting the motor 300 to the lens unit 200 is well known to the skilled artisan, it will not be described herein in detail. [0029] The shell unit 100 includes a receiving box 11 having a lens hole 111 , and a cap 12 having a lens hole 121 aligned with the lens hole 111 of the receiving box 11 along a longitudinal axis (L). The receiving box 11 cooperates with the cap 12 to define a receiving space 13 for receiving the lens unit 200 . The lens hole 121 of the cap 12 is formed as a stepped hole configuration, and includes a large diameter ring portion 122 , a small diameter ring portion 123 , a shoulder face 124 between the large and small diameter ring portions 122 , 123 , and an annular groove 125 formed in the shoulder face 124 . The shell unit 100 further includes a protecting lens 14 mounted to the large diameter ring portion 122 , and a leak-proof element 15 mounted in the annular groove 125 to achieve air-tight and water-proof effects for the lens hole 121 of the cap 12 . [0030] The lens unit 200 is mounted in the receiving space 13 , and includes a front lens portion 21 proximate to the cap 12 , a rear lens portion 22 opposite to the front lens portion 21 and distal from the cap 12 , a large diaphragm plate 23 mounted between the front lens portion 21 and the rear lens portion 22 , a small diaphragm plate 24 mounted pivotally between the front lens portion 21 and the rear lens portion 22 and rotatable relative to the large diaphragm plate 23 , a shutter plate 25 mounted pivotally between the front lens portion 21 and the rear lens portion 22 and rotatable relative to the large diaphragm plate 23 , first and second actuating elements 26 , 27 mounted on the rear lens portion 22 , and first and second pivot axles 221 , 222 mounted between the front and rear lens portions 21 , 22 and distal from each other. In the preferred embodiment, the first and second pivot axles 221 , 222 are mounted on the rear lens portion 22 and protrude toward the front lens portion 21 . [0031] Referring to FIG. 7 , the large diaphragm plate 23 has a large aperture 231 . The small diaphragm plate 24 has a first pivot portion 241 pivotally connected to the first pivotal axle 221 , a swing portion 242 opposite to the first pivot portion 241 , a first actuated portion 243 proximate to the first pivot portion 241 , and a small aperture 244 provided in the swing portion 242 . The first actuated portion 243 has an elongate hole 2431 . The first actuating element 26 includes an electromagnetically operated rod 261 slidable in the elongated hole 2431 in the small diaphragm plate 24 . [0032] Referring to FIGS. 5 and 9 , the shutter plate 25 has a second pivot portion 251 pivotally connected to the second pivot axle 222 , a shading portion 252 opposite to the second pivot portion 251 , and a second actuated portion 253 proximate to the second pivot portion 251 . The second actuated portion 253 has an elongate hole 2531 . The second actuating element 27 includes an electromagnetically operated rod 271 slidable in the elongated hole 2531 in the shutter plate 25 . [0033] Referring to FIGS. 7 and 8 , when a camera including the miniaturized lens assembly of this invention is operated by a user, the result of light detection is transmitted to the lens unit 200 . The first actuated portion 243 can be actuated by the first actuating element 26 to move the small diaphragm plate 24 from a first position in which the small aperture 244 is aligned with the large aperture 232 , to a second position in which the small aperture 244 is moved away from the large aperture 231 . [0034] Referring to FIGS. 9 and 10 , when the second actuating element 27 is driven by the user through operation of a button (not shown), the second actuated portion 253 is actuated by the second actuating element 27 to move the shutter plate 25 from an open position in which the shading portion 252 is away from the large aperture 231 , to a closed position in which the shading portion 252 covers the large aperture 231 so as to achieve the purpose of controlling the exposure time. [0035] In view of the aforesaid, the miniaturized lens assembly of this invention has the following advantages: [0036] 1. The small diaphragm plate 24 and the shutter plate 25 are controlled respectively by the first and second actuating elements 26 , 27 , which are mounted on the rear lens portion 22 . The lens unit 200 is constructed by assembling the front lens portion 21 , the rear lens portion 22 , the large diaphragm plate 23 , the small diaphragm plate 24 , the shutter plate 25 , the first actuating element 26 , and the second actuating element 27 together. Therefore, the lens assembly of this invention is miniaturized as compared to the conventional lens assembly. [0037] 2. The first and second actuating elements 26 , 27 for respectively actuating the small diaphragm plate 24 and the shutter plate 25 are mounted on the rear lens portion 22 , rather than on the shell unit 100 . Therefore, testing of the lens unit 200 can be conducted before being mounted in the shell unit 100 . The process for making the miniaturized lens assembly of this invention is simplified accordingly. [0038] 3. The first and second pivot axles 221 , 222 are mounted on the rear lens portion 22 . The electromagnetically operated rod 261 of the first actuating element 26 and the electromagnetically operated rod 271 of the second actuating element 27 can be recognized easily after the first and second actuating elements 26 , 27 are mounted on the rear lens portion 22 . Therefore, the large diaphragm plate 23 , the small diaphragm plate 24 , and the shutter plate 25 can be assembled with relative ease. [0039] 4. The small diaphragm plate 24 and the shutter plate 25 are actuated directly by the first actuating element 26 and the second actuating element 27 , respectively. No additional coupling mechanism is required between the small diaphragm plate 24 and the first actuating element 26 or between the shutter plate 25 and the second actuating element 27 . Therefore, the accuracy for controlling movement of the small diaphragm plate 24 and the shutter plate 25 is increased. [0040] While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.	A miniaturized lens assembly includes a front lens portion, a rear lens portion, a large diaphragm plate mounted between the front and rear lens portions, a small diaphragm plate rotatable relative to the large diaphragm plate, a shutter plate rotatable relative to the large diaphragm plate, first and second actuating elements mounted on the rear lens portion, and two pivot axles mounted between the front and rear lens portions. The miniaturized lens assembly is miniature in size, is simple in structure, and is easy to assemble.	6
CROSS-REFERENCE TO RELATED APPLICATIONS Reference is made to commonly assigned copending patent applications Ser. No. 279,629, filed simultaneously herewith in the name of Kevin P. McGuire and entitled APPARATUS FOR EXPOSING PHOTOGRAPHIC MATERIALS; and Ser. No. 279,623, field simultaneously herewith in the name of Kevin P. McGuire and James D. McKay and entitled VARIABLE BRIGHTNESS LIGHT GENERATORS. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to sources of illumination of constant color temperature and intensity. 2. Description Relative to the Prior Art In the manufacture and use of photographic materials, such as film or paper, it is necessary to know how the film or paper responds to light. More particularly, it is necessary to know how the film or paper responds to a range of intensities of light at each of a range of different wavelengths. To make meaningful tests, it is necessary to have known intensities at known wavelengths. It is known to use as a source of illumination for such tests, a source of white light which is manufactured at constant brightness, and to use filters to select wavelengths and intensities of exposing illumination in a plurality of sequential tests. However, the need has been recognized for a source of illumination which has superior constancy of color temperature and intensity, so that the tests on film can be more accurate. SUMMARY OF THE INVENTION The present invention provides a source of illumination of superior constancy of color temperature and intensity. Such a source, in accordance with the present invention, includes a generator of light the color temperature of which is dependent on the power applied to the generator. The source also includes a device for measuring the intensity of selected portions of the spectrum of light produced by the generator, and which produces signals indicative of these intensities. The source further includes first means responsive to said signals for adjusting the power applied to the generator, whereby a selected color temperature may be achieved. Also, there are second means responsive to the signals, for adjusting the intensity of the light emittted by the generator, without varying the power applied to the generator, whereby the intensity may be changed without changing the color temperature. With such a source, adjustments may be made to the color temperature to keep it within tolerance and then the intensity may be adjusted to keep it within tolerance. Because the intensity can be changed without affecting color temperature, both the color temperature and the intensity of the illumination may be maintained very close to their desired values in a simple and speedy manner. In one embodiment, the generator of light includes an incandescent lamp and the first means responsive to the signals adjusts the electrical power applied to the lamp. The second means for adjusting the intensity of the light produced by the generator may include a spherical mirror with the bulb located at the center of the spherical form of the mirror. A modulator is located between the mirror and the bulb for modulating the brightness of the image of the bulb formed on the bulb by the mirror. The modulator may be of the variable aperture type and, in one embodiment, may include two shutters movable towards and away from one another across the path of light from the bulb to the mirror. The modulator may include a stepping motor for driving one of the blades towards and away from the other of said blades, and a lever for transmitting motion from said one of said blades to the other of said blades but in the opposite direction. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: FIG. 1 is a diagrammatic representation of a sectional side elevational view of an apparatus, embodying a source of illumination of constant color temperature and intensity, in accordance with the present invention, for exposing photographic film; FIG. 2 is a diagrammatic representation of a view taken on the line 2--2 of FIG. 1; FIG. 3 is a diagrammatic representation of a view in the direction 3--3 in FIG. 1, of a lamp and its supporting structure, included in the apparatus illustrated in FIG. 1; FIG. 4 is a view of the lamp and its supporting structure, as illustrated in FIG. 3, but seen from the direction 4--4 in FIG. 3; FIG. 5 is a view from above, that is, the direction 5--5 in FIG. 4, of the lamp and its supporting structure illustrated in FIGS. 3 and 4; FIG. 6 is a view in the direction 6--6 indicated in FIG. 1; FIG. 7 is a flow chart representing the procedure for maintaining the color temperature and the brightness of the illumination source in the apparatus illustrated in the preceding Figures; and FIG. 8 is a diagram of a control circuit for the apparatus illustrated in preceding Figures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is made to FIGS. 1 to 5 of the accompanying drawings, which illustrate apparatus 20 for exposing photographic film or paper, embodying a source of illumination of constant color temperature and intensity, in accordance with the present invention. The apparatus 20 includes a generally cuboidal opaque housing 22 which is divided into five compartments 24, 26, 28, 30 and 32 by four baffles 34, 36, 38 and 40. Each baffle 34, 36, 38 and 40 has two apertures 34a, 34c; 36a, 36c; 38a, 38c; and 40a, 40c, respectively, to allow light to pass from one compartment to the adjacent compartment. The apertures 34a, 36a, 38a and 40a are rectangular and aligned with one another and the apertures 34c, 36c, 38c and 40c are circular (only aperture 40c being shown in the drawings, see FIG. 6) and aligned with one another and behind the plane of the paper bearing FIG. 1. The baffles 34, 36, 38 and 40 are opaque and join the housing 22 at their outer peripheries so that the only path for light between one compartment and the next is through the apertures 34a, 34c; 36a, 36c; 38a, 38c or 40a, 40c. The baffles and the internal surface of the housing 22 are all painted with a highly light-absorbent black paint, for example, ECP 2200 Solar Absorber paint manufactured by 3M. The compartment 24 houses components of an illumination source in accordance with the present invention. The components of the illumination source located in the compartment 24 form a light generator 44 and include a lamp 41, a mirror 46 and a light modulator 48. Another component of the illumination source is located in the fifth compartment 32, and will be described subsequently herein. The lamp 41 is a tungsten halogen bulb 42 which is mounted in a ceramic bulb holder 50. The power for the bulb 42 is supplied from a power supply 45, shown in FIGS. 7 and 8. The bulb holder 50 is detachably engaged with a socket 52 which is carried on top of a positioning device 54 which, for the sake of clarity, is omitted from FIG. 1 but is shown in detail in FIGS. 3, 4 and 5. The positioning device 54 serves to position the filament of the bulb 42 in five dimensions, namely along the z axis, which is parallel to the plane of FIG. 1, that is, it runs the length of the apparatus illustrated in FIG. 1; along the y axis, which is perpendicular to the z axis but is also in the plane of the paper bearing FIG. 1; along the x axis, which is orthogonal to the z and y axes; angularly about the x axis, which may be termed θx; and angularly about the y axis, which may be termed θy. The x, y and z axes are indicated in FIGS. 1 to 6 to aid understanding. Positioning along the z axis is achieved by a slideway 56 and a screw 58 working between a part 60 associated with the track 56t of the slideway 56, and a part 62 associated with the carriage 56c of the slideway 56. Positioning along the x axis is achieved by screws 66 which extend through slots 64, extensive in the x direction, through base 70. Positioning along the y axis is achieved by shims 68 between the track 56t and the base 70 and between the part 60 and the base 70. The base 70 is fixedly secured to the housing 22 by means not illustrated. The orientation about the x axis is held, i.e. θx is held, by clamping screws 72. θx is selected, after slackening of the screws 72, by rotation in a pinion 74 secured to shaft 76 rotatably mounted in trunnion 78. The pinion 74 cooperates with a rack 80 to drive the holder 52 in rotary motion about the axis of shaft 76. Orientation about the y axis is selected by rotation of the socket 52 connected to a sub-base 53 and is held by locking screws, not shown. An ejector lever 82 is provided to facilitate removal of the lamp 41 from its socket 52. The mirror 46 is spherical and the filament of the bulb 42 is located at the center of the spherical shape of the mirror 46. The mirror 46 is mounted from the housing 22 by means (not shown) which enable the mirror to be selectively positioned along the x and y axes. The bulb 41 is a low-voltage tungsten halogen bulb (e.g. a Thorn model L9390 bulb) and has such a small filament that it is only a small approximation to say that the filament is located at the center of the spherical form of the mirror 46. The reflective surface of the mirror 46 is specularly reflective aluminum. The light modulator 48 is diagrammatically represented in FIG. 1 and is represented in more detail in FIG. 2. In the present embodiment, the modulator is of the variable aperture type. The modulator 48 includes a base plate 84 which is attached to the housing 22 and to which the other components of the modulator are directly or indirectly attached. The modulator, in the present embodiment of the invention, is of the sliding shutter type, sometimes termed a sliding barn door type, and includes two shutter blades 86 and 88, respectively, mounted by slideway means, not shown, for guided rectilinear siding movement relative to the base plate 84, along the x axis. The blades are driven in opposite directions by a stepping motor 90 which drives a screwthreaded shaft 92 cooperating with a nut 94 secured to the blade 88. The motor 90, shaft 92 and nut 94 serve to drive the blade 88 along the x axis, that is, left to right as seen in FIG. 2. Motion is transmitted from the blade 88 to the blade 86 by a lever 96 which is rockable about a pivot 98 at its center. The lever is operatively connected to the blades 86 and 88 by yoke 100 and pin 102 arrangements. The blade 86, like the blade 88, is constrained to move rectilinearly along the x axis by guide means, not shown. To take slack out of the system, there is a spring 104 which biases the blade 86 to the right, as seen in FIG. 2, and, through the lever 96, biases the blade 88 from right to left, as seen in FIG. 2. Sensors 106 sense the positions of the blades 86 and 88, at least when their adjacent edges are close to one another, in order to provide signals which serve to prevent the motor driving the blades closer to one another. In this way, contact, and possible consequential damage, of the edges of the blades may be prevented. The blades are formed of the same material as the reflecting surface of the mirror 46, which material, in the present embodiment, is aluminum. The surface of the mirror is specularly reflective and the blades have been bead blasted which renders them diffusely reflective. By having the blades and the reflective surface of the mirror made of the same material, light reflected by the mirror 46 and by the surfaces of the blades 86 and 88, has the same spectral composition. Also in the compartment 24 is a filter 108 which absorbs infrared light so that heating of components on which light is incident subsequently in the apparatus, is reduced. The compartment 24 also contains a shutter 110 which, in the present embodiment, is a focal plane shutter. The shutter is sealed to the baffle 34, over the aperture 34a and 34c, so that light from the bulb can leave the compartment and pass to the compartment 26 through the apertures 34a and 34c, only when the shutter 110 is open. The compartment 26 contains a flash light source in the form of a xenon strobe bulb 112. The bulb 112 is located outside the space bounded by a tubular surface which contacts continuously the peripheries of the apertures 34a and 36a in the baffles 34 and 36, respectively. Located at the far side of the just-mentioned space bounded by the tubular surface, is a mirror 114. The mirror 114 is mounted on the rod 116 of a piston and cylinder device 118. The piston and cylinder device 118 serves to move the mirror into and out of the just-mentioned tubular space (i.e. parallel to the y axis), it being shown in the out position in FIG. 1. The mirror 114 is disposed at 45° to the z axis so that it reflects light from the strobe bulb 112 along the z axis, i.e. along the just-mentioned tubular space through successive apertures 38a and 40a. In the compartment 28 there are a plurality, in the present example, ten, of filters 120 to 138. The filters 120 to 138 are carried by rods 120r to 138r of piston and cylinder units 120c to 138c. Operation of the piston and cylinder units 120c to 138c serves to move the respective filters 120 to 138 along the y axis into and out of positions in which they intercept light from the lamp 41 passing from apertures 36a, 36c to apertures 38a, 38c. When in the inoperative positions, illustrated in FIG. 1, the filters are disposed entirely out of intercepting relationship with light passing directly from apertures 36a, 36c to apertures 38a, 38c. The filters 120 to 128 include a plurality of gray filters of different densities, so that, by the insertion of one or more of them, the intensity of the light passing to the film can be selectively attenuated by any one of a plurality of values. The filters 120 to 128 also include a plurality of filters so constructed as to pass only selected bands of wavelengths of the light incident on them. Thus, by appropriate selection and insertion of filters, light of a predetermined intensity and band of wavelengths may be caused to be incident on the film. Of course, with an appropriate filter or filters, a very narrow band of wavelengths, or even a `line`, may be allowed to pass to the film. Schematically represented in compartment 30 in FIG. 1 are means 140 for receiving and holding a filter different to those in the back of filters in the compartment 28. The filter inserted at the means 140 might be one used infrequently or uniquely for a special test. The baffle 40 is visible in FIG. 6. The aperture 40a is closeable and openable by an opaque door 142 which is attached to the baffle 40 by hinges 144. The door is openable and closeable by a piston and cylinder unit 146 operating on a lever 148 attached radially of a shaft 150 which is parallel to the y axis and which extends through the hinges 144 and which is secured to the door 142. As can be seen in FIG. 6, the circular aperture 42c is located close adjacent the aperture 40a and is much smaller. The circular aperture 42c allows passage of light from the compartment 30 to a spectroradiometer 154 located in the compartment 32. The only access for light to the interior of the spectroradiometer 154 is through the aperture 40c and a tubular shroud 156 leading from the aperture 40c to the spectroradiometer. The spectroradiometer constitutes another component of the illumination source. Upon entering the spectroradiometer, light passes through a depolarizer (not illustrated) which consists of two crystal quartz wedges with their fast axes disposed at 45° to one another and with one wedge being twice the thickness of the other. The use of wedges ensures that the depolarizer is achromatic. The ratio of the thicknesses and the orientation of the fast axes eliminates any fast axis. The apertures 34a, 35a and 38a are so sized and disposed that light from the bulb and mirror 46 directly, without any reflection, is incident on all portions of the aperture 40a. Also, the apertures 34a, 36a, 38a and 40a are so sized and disposed that if an eye were substituted for the filament of the bulb 42 and it looked along the z axis, it would see: a margin of the baffle 36 entirely encompassing the aperture 36a; a margin of the baffle 38 entirely encompassing the aperture 38a; and a margin of the baffle 40 entirely encompassing the aperture 40a. The apertures 34c, 36c, 38c and 40c are aligned so that the spectroradiometer 154 can `see` the bulb 42. Fixedly mounted in an end wall 157 of the compartment 32 is a step wedge 158 of known form for use in exposing photographic film to intensities of light which decrease progressively as the thickness of the wedge increases at each step. As is known, the step wedge is formed of transparent material which is uniformly grey so that its "optical density", that is, its ability to pass light, is directly dependent on its thickness. The step wedge is so disposed in the end wall of the compartment 32 that every portion of it can `see` the filament of the bulb 42. A pressure plate 160 is located at the side of the step wedge remote from the light generator 44 and is at least coextensive in area therewith. The pressure plate 160 is carried by the rods 162 of piston cylinder units 164 which serve to move the pressure plate 160 along the z axis with the plane of its surface facing the step wedge 158 parallel to the step wedge 158. As may be seen in FIG. 1, film strip for exposure is contained in a chamber 166 and enters the housing 22 through a light-tight port 168. After exposure, film is lead out of the housing 22, through light-tight port 170, into take-up chamber 172. Film is drawn into the take-up chamber 172 by a motor 173. The spectroradiometer 154 is of a form well-known to those skilled in the art and will not be described in detail herein. The spectroradiometer 154 takes light which has passed through the aperture 152 and the shroud 156 and images a spectrum from 380 to 740 nm onto a linear array of, in the present embodiment, thirty-two, photodiodes. Thus, the spectroradiometer 154 provides thirty-two signals indicative of the intensity of light in each of a thirty-two, uniform width bands together extending from 380 to 740 nm. The value of the color temperatures and illuminance for thirty-two wavelengths nominally at the middle of each of the thirty-two bands, are derived from the thirty-two signals from the sensors. The spectral values are multiplied by the X, Y and Z tristimulus values and from these the color coordinates, luminosity of radiant power and color temperature can be derived. FIG. 8 is a diagram of the control system for the stepping motor 90; the power supply 45; the piston cylinder 118 for positioning the mirror 114; the piston cylinder 120c to 138c (of which only a representative piston cylinder 120c is illustrated) for positioning the filters 120 to 138; the piston cylinder 146 for positioning the door 142; the piston cylinders 164 for positioning the platen 160; and the motor 173 for drawing film into the take-up chamber 172. The control system includes an automatic control 174 for controlling the stepping motor 90 and the power supply 45, and a manually controlled control 176. The entire apparatus is maintained at a stable temperature by means, not shown in the drawings and not to be further described herein, well known to those skilled in the art. In operation, film to be exposed is loaded in the chamber 166, and lead through the port 168, and between the pressure plate 160 and the step wedge 158, to the port 170 and thence to the take-up chamber 172. The pressure plate 160 is moved forward by the piston cylinder units 164 so that the film is pressed against the wedge 158. At this time, the door 142 is closed and the bulb 42 has been on for some time so that the system is stabilizing. The shutter 110 is open so that light can be incident in the spectroradiometer 154. All of the filters 120 to 138 are in out, non-effective positions (i.e. as illustrated in FIG. 1). The mirror 114 is also in its out, non-effective position (i.e. as illustrated in FIG. 1). Power is supplied to the bulb 42 by the power supply 45. The output of the power supply is under the control of the automatic control 174 which causes the power applied to the bulb to vary depending on whether the color temperature and illuminance, as measured by the spectroradiometer 154, are within tolerances. FIG. 7 is a flow chart with the bulb 42; the spectroradiometer 154; the automatic control 174; the stepping motor 90; and the power supply 45 being represented. As represented in the flow chart, light from the generator 44 is incident in the spectroradiometer 154. The spectroradiometer generates signals indicative of the illuminance and the correlated color temperature, which are transmitted to the automatic control 174. The automatic control 174 tests the signals to see whether they are within tolerance. The color temperature signal is tested first and if it is not within tolerance it sends a signal to the power supply to bring the color temperature back within tolerance, which is achieved by variation of the power applied to the bulb 42. Thus, the automatic control 174 and the power supply 45 constitute means responsive to signals for the spectroradiometer 154 for adjusting power supplied to the generator. The illuminance signal is tested when the color temperature signal is within tolerance. If the illuminance signal is out of tolerance, the automatic control 174 signals the stepping motor so as to bring the signal back within tolerance by variation of the spacing between the shutter blades 86 and 88. Thus, the automatic control 174 and the stepping motor 90 form means responsive to signals from the spectroradiometer for adjusting the intensity of the light emitted by the generator. Whenever the shutter 110 is open, the automatic control 174 is operating to maintain the color temperature and the illuminance of the bulb 42 within tolerance. Whenever the illuminance and color temperature of the bulb are within tolerance, an enabling signal is sent by the automatic control 174 to the manually controlled control 176, through lead 178. The manually controlled control 176 controls all those features which are not under the automatic control 174 and are related to actually exposing a strip of film as distinct from the maintenance of illuminance and color temperature of the bulb 42. Film has been loaded as described above, the door 142 being in a closed condition of the loading. A program for the exposures of the film is entered into the manually controlled control 176. The program might include exposure with none of the filters 120 to 138 in the light path; successive exposures with selected filters 120 to 138 in the light path; and an exposure with the exposing light being derived from the xenon tube 112. The film is advanced by the motor 173 between successive exposures, with sufficient film being advanced after each exposure that exposed film is entirely within the take-up chamber when the next exposure is made. When the operation is initiated, the control 176 causes the shutter 110 to close. The door 142 is then opened by a signal from the control 176 to the piston cylinder 146. The shutter 110 is then caused to open for a predetermined brief period, after which it again closes. The control then causes the piston cylinders 164 to withdraw the platen 160 and then to energize the motor 173 so that the film is advanced. The control 176 then causes the piston cylinders 164 to move the platen 160 forward so that the film is again pressed against the step wedge 158. The control then causes a selected filter 120 to 138 to be moved, by its associated piston cylinder 120c to 138c, in the path of light. The shutter 110 is again opened and closed by the control 176. The operation for advancing the film is repeated and the previously used filter is withdrawn and another filter is inserted in the light path. This procedure is repeated until all the exposures with the exposing light being derived from the generator 44, have been completed. With bulb-derived-light exposures completed, the control causes the piston cylinder 118 to move the mirror 114 into its operative position. The door 142 is then closed so that the strobe 112 can be flashed several times, under the control of the control 176, so that a stable output of the strobe is achieved. When stability of the output of the strobe is achieved, flashing of the strobe is stopped and the control 176 causes the piston cylinder unit 146 to open the door 142. The strobe is again flashed and the film is advanced, as described above, except that the door 142 need not be closed. Subsequent exposures with the strobe providing the light and with a different selected filter in the light path for each exposure, are then effected, as programmed into the control 176. The five degrees of freedom and positioning of the filament of the bulb, were described above. These degrees were x, y, z, θx and θy. They are adjusted when the apparatus is being set up and they are adjusted with the intent of graining uniform illumination on the wedge 158. It has been observed that the θx adjustment affects uniformity of illumination along the y axis and the θy adjustment affects uniformity of illumination along the x axis. It has been found that, in one embodiment of the present invention generally as described above, the modulator 48 can effect a 40% variation in the illuminance on the wedge. It will have been understood that the modulator serves to vignette the image of the filament formed on the filament of the bulb 42 by the mirror 46. It will have been understood that the modulator 48 is used to maintain constant the intensity of the light emitted by the light generator and it is not used to vary the intensity of the light emitted by the generator for the purpose of creating different exposures of the photographic film. The filters 124 to 138 serve the purpose of creating different intensities of light incident on the step wedge, by varying the amount of light passed from the constant intensity light generator. The fact that a margin of each baffle 36, 38 and 40 around the aperture 36a, 38a and 40a in the baffle can be `seen` by the bulb filament through the aperture in the preceding baffle has been found to improve uniformity of illumination and color temperature. As can be seen in the drawings, the modulator shutter blades 86 and 88 are, in the embodiment illustrated and described above, rectangular. Advantages may be achieved in other embodiments if the facing edges of the two blades are given a non-rectilinear, for example, saw-tooth, form. In the embodiment particularly described above, the shutter blades are formed of the same material as the reflective surface of the mirror. In other embodiments, the surface of the blades facing the bulb may be made totally absorptive of the light incident on them. In this way also, the color temperature of the light issuing from the generator, i.e. the bulb, mirror and modulator, will not be effected by the condition of the modulator, e.g. the opening of the shutter blades. In the embodiment described above, the light modulator is of the variable aperture type, and, particularly, is in the form of two shutter blades which are selectively positioned relative to one another. It is to be understood that the modulator may take other forms. For example, the modulator could include crossed polarizers with the inclination between their planes of polarization being variable to vary the modulation of light passed by them; pass wedges with increasing density across the optical, i.e. the z, axis; a two-axis venetian blind; or any other type of optical switch or shutter which, when actuated to vary modulation, does not affect color temperature or uniformity of illumination. The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.	A source of illumination of constant color temperature and intensity including a lamp the color temperature of the light from which is dependent on the power applied to the lamp. There is a device for measuring the intensity of portions of the spectrum of the light and for providing signals indicative of those intensities. Means responsive to the signals adjust the power to achieve the selected color temperature. A light modulator adjusts the intensity without affecting color temperature. There is a spherical mirror centered on the lamp and the modulator is located between the lamp and the mirror and controls the brightness of the image of the lamp formed on the lamp by the spherical mirror.	5
TECHNICAL FIELD [0001] The present invention relates to a silicon substrate having a textured surface and a manufacturing method thereof. BACKGROUND ART [0002] In a silicon solar cell (photovoltaic device), unevenness referred to as a texture is provided on a light-receiving surface of a silicon substrate so as to prevent reflection of incident light and leakage of light trapped on the silicon substrate. A surface of a silicon substrate is usually textured by a wet process using an alkaline (KOH) solution as an etchant (see PTL 1, PTL 2, PTL 3, and PTL 4). The texturing by a wet process requires post-processes such as a cleaning process using hydrogen fluoride and a thermal process. Not only may the post-processes contaminate a surface of a silicon substrate, but they also have a disadvantage with regard to increased cost. [0003] In addition, the wet process only allows texturing a silicon substrate having orientation (100) (see PTL 5, for example), and the wet process cannot form a texture on a surface of a silicon substrate having another orientation. [0004] Techniques for forming a texture on a surface of a silicon substrate by a dry process have also been proposed. For example, 1) a technique using reactive ion etching by plasma (see PTL 6 and PTL 7), 2) a technique for etching by a photo-electrolysis reaction (PTL 8), and 3) a technique for etching a surface of a silicon substrate by introducing ClF 3 gas and others into a reaction chamber in which the silicon substrate is placed (see PTL 9, PTL 10, and PTL 11) have been proposed. CITATION LIST Patent Literature [0000] PTL 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2011-515872 PTL 2: Japanese Patent Application Laid-Open No. 2008-172279 PTL 3: United States Patent Application Publication No. 2009/0280597 PTL 4: United States Patent Application Publication No. 2010/0193027 PTL 5: Japanese Patent Application Laid-Open No. 2000-150937 PTL 6: Japanese Patent Application Laid-Open No. 2002-164555 PTL 7: Japanese Patent Application Laid-Open No. 2000-12517 PTL 8: United States Patent Application Publication No. 2002/0104562 PTL 9: Japanese Patent Application Laid-Open No. 10-313128 PTL 10: Japanese Patent Application Laid-Open No. 2005-150614 PTL 11: United States Patent Application Publication No. 2005/0126627 SUMMARY OF INVENTION Technical Problem [0016] As described above, by a wet process, a texture can only be formed on a silicon substrate having orientation (100). Accordingly, forming a texture on a silicon substrate having another orientation would result in an unconventional unique texture. [0017] For example, the texture formed by a wet process has projections with the height of 10 to 20 μm. The thickness of the entire silicon substrate is naturally greater than the thickness of the projections. As a result, the thickness of the silicon substrate ends up being greater than the thickness required for a silicon substrate used for a solar cell. In contrast, forming a finer texture can reduce the thickness of the entire silicon substrate, increasing material efficiency of silicon. [0018] As described above, a method for forming a texture on a surface of a silicon substrate by a dry process has been proposed. However, with this method, a desired structure of texture may not be achieved. One reason is that a gas such as ClF 3 , XeF 2 , BrF 3 and BrF 5 causes a reaction generating heat with a silicon substrate, increasing the temperature of the silicon substrate. Consequently, anisotropic etching may not be performed. Furthermore, since the composition of the etching gas is not optimized either, it was difficult to achieve a proper texture. [0019] In view of the problems, it is an object of the present invention to provide a silicon substrate having a new textured surface by forming a texture on a surface of a silicon substrate having orientation (111) preferably by dry etching. It is another object of the present invention to provide a solar cell including the silicon substrate. Solution to Problem [0020] The present invention relates to a silicon substrate having a textured surface and a solar cell including the silicon substrate described as follows. [1] A silicon substrate having orientation (111) and a textured surface on which a textured structure is formed, in which the textured surface has a plurality of projections each having three slant faces, and a height of the projections is in a range from 100 nm to 8 μm. [2] The silicon substrate according to [1], in which the height of the projections is in a range from 100 nm to 5 μm. [3] The silicon substrate according to [1] or [2], in which a side of a bottom surface of each of the projections has a length in a range from 100 nm to 8 μm. [4] The silicon substrate according to any one of [1] to [3], in which a density of the projections on the textured surface is 10 to 1,000/100 μm 2 . [5] The silicon substrate according to any one of [1] to [4], in which an absorbance of incident light having a wavelength of 0.5 μm to 10 μm on the textured surface of the silicon substrate is 80% or higher. [6] A solar cell including the silicon substrate according to any one of [1] to [5], in which the textured surface is used as a light-receiving surface of the solar cell. [0027] The present invention also relates to a method for manufacturing a silicon substrate having a textured surface described as follows. [7] A method for manufacturing the silicon substrate according to [1], the method including: providing a silicon substrate having orientation (111); and blowing an etching gas on a surface of the silicon substrate, in which the etching gas contains (i) at least one gas selected from the group consisting of ClF 3 , XeF 2 , BrF 3 , BrF 5 , and NF 3 , and (ii) a gas containing an oxygen atom in a molecule thereof. [8] The method according to [7], in which the etching gas further contains an inert gas. [9] The method according to [7] or [8], in which a temperature of the silicon substrate is maintained at a temperature of 200° C. or lower. [10] The method according to any one of [7] to [9], in which etching on the silicon substrate is performed under a reduced-pressure environment. Advantageous Effects of Invention [0032] The silicon substrate according to the present invention has a textured surface with a low reflectance. Accordingly, by setting the textured surface as a light-receiving surface, the silicon substrate can be suitably used as a silicon substrate for a solar cell. Furthermore, since the texture according to the present invention is a fine-structure, it is possible to reduce the thickness of the silicon substrate, increasing the material efficiency of the silicon substrate, which will increase flexibility in designing a device. BRIEF DESCRIPTION OF DRAWINGS [0033] FIGS. 1A to 1F are electron micrographs of a textured surface on a silicon substrate according to Examples; [0034] FIGS. 2A and 2B show an example in which a desired textured surface is not formed by dry-etching on a silicon substrate; [0035] FIGS. 3A and 3B show an example in which a desired textured surface is not formed by dry-etching on a silicon substrate; [0036] FIG. 4 schematically illustrates a projection having three slant faces; [0037] FIGS. 5A and 5B illustrate an overview of a texturing apparatus used in Examples; [0038] FIG. 6A is a graph representing reflectance of a non-textured surface on a silicon substrate having orientation (111) (Reference Example) and a textured surface on a silicon substrate obtained in Example; [0039] FIG. 6B is a graph representing absorbance of a non-textured surface on a silicon substrate having orientation (111) (Reference Example) and a textured surface on a silicon substrate obtained in Example; [0040] FIGS. 7A to 7C show an assumption on reaction mechanism by which a textured structure is formed; [0041] FIGS. 8A to 8D show textured surfaces of a silicon substrate obtained in Example 2; and [0042] FIGS. 9A to 9D show textured surfaces of a silicon substrate obtained in Example 3. DESCRIPTION OF EMBODIMENTS 1. Silicon Substrate Having Textured Surface [0043] A silicon substrate according to the present invention has a feature in a textured surface on the substrate. The textured surface refers to a surface of the substrate having the textured structure. [0044] It is preferable that the silicon substrate is made of single-crystal silicon; the silicon substrate may be doped with a p-type impurity or an n-type impurity, or may be intrinsic silicon. The silicon substrate has orientation (111). A silicon substrate having orientation other than (111) is not likely to have the textured surface according to the present invention. [0045] One feature of the silicon substrate having the textured surface according to the present invention is that the orientation of the silicon substrate is (111). Conventional wet etching allows a silicon substrate with orientation (100) to have a textured surface. However, the conventional wet etching cannot form the textured surface on the silicon substrate having the orientation (111), and such a substrate is isotropically etched instead. [0046] The textured surface refers to a surface having a low reflectance. A low reflectance surface is a surface preferably having a reflectance of approximately 20% or less, more preferably 10% or less, and refers to a surface having a reflectance of substantially 0%, when a reflectance of a mirror surface for light having a wavelength from 0.5 to 1.0 μm is set as 100%. The silicon substrate having the textured surface according to the present invention preferably has an absorbance (a wavelength range of 0.5 to 1.0 μm) of 80% or higher, and more preferably 85% or higher. The absorbance can be measured by a sphere spectrophotometer, and can be calculated by the following equation; absorbance(%)=100×{intensity of incident light−(intensity of reflected light+intensity of transmitted light)}/intensity of incident light. [0047] More specifically, the textured surface according to the present invention has projections each having three slant faces (see the schematic diagram in FIG. 4 for details). The projection having the three slant faces may be a projection having the shape of a triangular pyramid. It is preferable that the textured surface has the projections with three slant faces closely formed with each other. Each of the three slant faces has orientation (110), (101), or (011), which is different from orientation (111). It is preferable that the projection has an apex. [0048] The height H of the projection having three slant faces (see FIG. 4 ) is usually 100 nm to 8 μm, preferably 100 nm to 3 μm, more preferably 100 nm to 1.5 μm, and even more preferably 100 nm to 1 μm. In addition, the length L of a side of the bottom surface of the projection having three slant faces (see FIG. 4 ) is usually 100 nm to 8 μm, preferably 100 nm to 3 μm, more preferably 100 nm to 1.5 μm, and even more preferably 100 nm to 1 μm. [0049] The angle θ of the apex of the projection having three slant faces (see FIG. 4 ) is preferably 54.7°±10°. [0050] A feature of the silicon substrate having the textured surface according to the present invention is that the projections composing the texture are small. Projections in the textured structure formed by the conventional wet etching or ion plasma etching are much higher (for example, the height of a textured structure formed by wet etching is from 10 to 20 μm), and it was not possible to form miniaturized projections as in the present invention. The more miniaturized the structure of the texture, the more suppressed reflection of light on the textured surface. For example, if the processing accuracy of the textured surface is 1 μm or less, the reflection of light having the wavelength of 1 μm is set to be nearly zero. [0051] Another feature of the silicon substrate having the textured surface according to the present invention is that the thickness of the silicon substrate can be reduced. More specifically, since the projections composing the textured structure are miniaturized, the thickness of the silicon substrate can be reduced as much as the reduced thickness of the projections. The thickness of the silicon substrate according to the present invention is 20 μm or less including the height of the projections, preferably 15 μm or less, and even more preferably 10 μm or less. The lower limit on the thickness of the silicon substrate is not particularly set as long as a sufficient strength as a substrate is maintained, and is usually 10 μm or more. [0052] The textured surface has a plurality of projections having three slant faces, and the projections having three slant faces may each have a different shape. A preferable density of the projections on the textured surface is 10 to 1,000 per unit area (100 μm 2 ). [0053] The surface of the silicon substrate may be entirely textured; alternatively, the silicon substrate may be partially textured. For example, when the silicon substrate according to the present invention is used as a silicon substrate for a solar cell, it is preferable that an area for a front surface electrode (including a connector electrode, a bar electrode, a grid electrode and others) provided on the light-receiving surface side preferably remains flat, without the textured structure. 2. Method for Manufacturing Silicon Substrate Having Textured Surface [0054] The method for manufacturing the silicon substrate according to the present invention includes: providing a silicon substrate having orientation (111), and blowing an etching gas on the silicon substrate. Preferably, the manufacturing method further includes blowing a cooling gas on the silicon substrate, and blowing the etching gas and the cooling gas may be alternately repeated. [0055] The silicon substrate having the orientation (111) is a single-crystal silicon substrate having a main surface with orientation (111). The silicon substrate may be a semiconductor wafer, or a semiconductor layer stacked on another substrate. In any case, the textured structure is formed on the surface having orientation (111), which is the orientation of the main surface. [0056] The silicon substrate provided may be made of intrinsic silicon, or silicon doped with a p-type or n-type impurity. A silicon substrate doped with a p-type impurity is usually provided for a silicon substrate for a solar cell. [0057] The etching gas is blown on the silicon substrate under a condition in which the pressure is in a range from the atmospheric pressure to 80 KPa. The pressure is preferably 30 KPa or lower, more preferably 20 KPa or lower, and even more preferably 10 KPa or lower, and may be 50 Pa or lower. The lower the pressure at the time of etching is, the finer the structure becomes; however, a higher pressure is likely to provide a smaller structure of texture. [0058] The etching gas includes at least one of ClF 3 , XeF 2 , BrF 3 , BrF 5 , and NF 3 (may be referred to as a “fluorine-containing gas”). The fluorine-containing gas included in the etching gas may be a mixed gas of two or more of the fluorine-containing gases described above. [0059] Molecules of the fluorine-containing gas are physisorbed on the surface of the silicon substrate, and migrate to an etching site. The molecules of the gas reached the etching site are decomposed, and a volatile fluoride is generated by a reaction with silicon. With this process, the surface of the silicon substrate is etched, forming a textured surface. [0060] It is preferable that the etching gas includes an inert gas, in addition to the fluorine-containing gas. The inert gas is nitrogen, argon, or helium gas, for example, and may be any gas that does not react with silicon. The inert gas included in the etching gas may be a mixed gas of two or more types of gases. [0061] The total concentration (volume concentration) of the inert gas in the etching gas is preferably three time or more than the total concentration of the fluorine-containing gas, and may be 10 times or more, or 20 times or more. The higher the total concentration of the fluorine-containing gas in the etching gas, the more likely the size of projections each having three slant faces increases (the height of the projections increases). Accordingly, in order to reduce the size of the projections, it is preferable to increase the concentration of the inert gas and to reduce the concentration of the fluorine-containing gas relative to the inert gas (see the following Examples 1 and 2). [0062] If the concentration of the inert gas in the etching gas is low and the concentration of the fluorine-containing gas is relatively high, the surface of the silicon substrate may be etched isotropically, which makes it difficult to form a desired textured structure on the surface of the silicon substrate. [0063] Furthermore, it is preferable that the etching gas includes a gas containing an oxygen atom in its molecule, in addition to the fluorine-containing gas. The gas containing oxygen atoms is typically oxygen gas (O 2 ); however, may be carbon dioxide (CO 2 ) or nitrogen dioxide (NO 2 ). [0064] The concentration of the gas containing oxygen atoms (volume concentration, at ordinary temperature) is preferably more than twice the total concentration of the fluorine-containing gas, and more preferably four times or more. The concentration of the gas containing oxygen atoms in the etching gas (volume concentration, at ordinary temperature) is preferably 30 to 80% of the total concentration of the fluorine-containing gas and the inert gas. When the concentration of the gas containing oxygen atoms in the etching gas is too low, the desired texture may not be achieved due to over-etching. [0065] By including the gas containing oxygen atoms in the etching gas, unevenness suitable for the textured structure in a solar cell may be formed on a surface of a semiconductor substrate. Although the mechanism is not particularly limited, when ClF 3 gas is physisorbed on the surface of silicon, ClF 3 reacts with the silicon, and SiF 4 is generated, which is gas. Here, by oxygen atoms terminating dangling bonds in a silicon network structure, Si—O bond is partially formed. As a result, a portion likely to be etched (Si—Si) and a portion unlikely to be etched (Si—O) are produced. It is assumed that the difference in the etching rates promotes chemical reactions, allowing controlling the shape of the structure. [0066] FIGS. 7A to 7C show an assumption on the mechanism of reactions when the textured structure on the surface of the semiconductor substrate is formed; however, the mechanism for forming the textured structure is not limited to this example. In an early stage of the textured structure formation ( FIG. 7A ), the etching reaction on silicon substrate 100 by the fluorine-containing gas (ClF 3 ) preferentially proceeds, and pores 110 are formed on the surface of silicon substrate 100 , making the surface into a porous structure. In an intermediate stage ( FIG. 7B ), the surface of porous silicon substrate 100 is oxidized by the oxygen-containing gas along the orientation of the surface, and oxidized layer 120 is formed. In a later stage ( FIG. 7C ), oxidized layer 120 serves as an etching mask, forming desired projections 130 (projections each having three slant faces). [0067] In the method for manufacturing the silicon substrate according to the present invention, it is important to maintain the temperature of the silicon substrate at a low temperature during etching. It is preferable to maintain the temperature of the silicon substrate at 200° C. or lower, more preferably 180° C. or lower, and even more preferably 160° C. or lower. In order to maintain the temperature of the silicon substrate at a low temperature, it is preferable to maintain the temperature of a stage for placing the silicon substrate approximately at room temperature (25° C.) or lower. The temperature of the silicon substrate during etching may be measured by an infrared temperature sensor or by providing a thermocouple. [0068] As described above, the method for manufacturing the silicon substrate according to the present invention may include blowing the cooling gas on the silicon substrate. The cooling gas is similar to the inert gas described above, and refers to nitrogen, argon, helium, or other gases. By blowing the cooling gas on the silicon substrate generating heat by the reaction with the etching gas, the heated substrate is cooled. [0069] In the method for manufacturing the silicon substrate according to the present invention, blowing the etching gas on the silicon substrate and blowing the cooling gas on the silicon substrate may be alternately repeated. By controlling the processing time for blowing the etching gas on the silicon substrate, the temperature of the substrate is maintained at a low temperature. Although the processing time is not particularly limited, the processing time may be approximately 1 minute to 10 minutes. After the etching gas is blown on the silicon substrate, the temperature of the substrate is decreased by blowing the cooling gas, and then the etching gas may be blown on the silicon substrate. [0070] When the desired textured structure is formed on the surface of the silicon substrate by the etching gas, it is preferable to remove the etching gas or a degradation product of the etching gas remaining on the silicon substrate. For example, the remaining fluorine component on the silicon substrate may be removed in a hydrogen gas atmosphere. [0071] In the method for manufacturing the silicon substrate according to the present invention, the blowing of the etching gas on the silicon substrate may be performed in two steps. More specifically, in the first step, processing using a fluorine-containing gas that does not contain gas containing oxygen atoms and an inert gas is performed, and a roughened surface as shown in FIG. 2A , 2 B, 3 A or 3 B, for example, is formed on the silicon substrate. In the second step, a chemical reaction is promoted by the difference in the etching rates generated through the process using the gas containing oxygen atoms, allowing controlling the shape of the surface of the substrate. 3. Use of Silicon Substrate Having Textured Surface [0072] As described above, the silicon substrate according to the present invention is preferably used as a silicon substrate for a solar cell. For adapting the silicon substrate to a solar cell, a p-n junction is preferably provided by forming an emitter layer on the textured surface of the silicon substrate. For example, when the textured surface is formed on a p-type silicon substrate, the textured surface is heated under a phosphorus oxychloride atmosphere, and an n-type emitter layer is formed on the textured surface so as to form a p-n junction. Stacking an anti-reflective layer on the emitter layer further reduces reflectance of the solar cell, improving a photoelectric conversion rate. The anti-reflective layer may be a silicon nitride layer, a silicon oxide layer, or a titanium oxide layer, for example. [0073] Subsequently, a front electrode is provided on a light-receiving surface which is the textured surface, and a back electrode is provided on the non-light-receiving surface, and thus a solar cell is implemented. Needless to say, an embodiment of the solar cell is not limited to the example described above. EXAMPLES Example 1 [0074] FIGS. 5A and 5B illustrate an overview of a texturing apparatus used in Examples. FIG. 5A is an external perspective view of texturing apparatus 10 , and FIG. 5B is a perspective view seeing through reduced-pressure chamber 20 . Texturizing apparatus 10 illustrated in FIGS. 5A and 5B includes, in reduced-pressure chamber 20 , nozzle 30 for blowing an etching gas, nozzle 40 for blowing a cooling gas, and stage 50 for placing silicon substrate 100 . Nozzle 30 for blowing the etching gas is connected to etching gas supply pipe 31 , and nozzle 40 for blowing the cooling gas is connected to cooling gas supply pipe 41 . A silicon substrate having a textured surface is manufactured by blowing the etching gas and the cooling gas on silicon substrate 100 placed on stage 50 . [0075] Silicon substrate 100 having orientation (111) is placed on stage 50 of texturing apparatus 10 illustrated in FIGS. 5A and 5B . The distance between nozzle 30 that blows the etching gas and silicon substrate 100 is set to be 5 mm The area of the surface of silicon substrate 100 is 125 mm×125 mm The temperature of stage 50 is set to 25° C. After the pressure of reduced-pressure chamber 20 is adjusted to 90 KPa, the etching gas through nozzle 30 is blown on the entire surface of silicon substrate 100 for 10 to 60 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/0 cc/2,000 to 10,000 cc”. [0076] Next, an etching gas through nozzle 30 having a different composition is blown on the entire surface of silicon substrate 100 for 60 to 120 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/500 to 5,000 cc/2,000 to 10,000 cc”. [0077] FIGS. 1A to 1D show electron micrographs of the textured surface of the silicon substrate obtained. As shown in FIG. 1A (1,000×) and FIG. 1B (3,000×), or FIG. 1D (1,000×) and FIG. 1E (3,000×), projections each having three slant faces are closely formed. Note that, FIG. 1B is an enlarged view of FIG. 1A , and FIG. 1E is an enlarged view of FIG. 1D . As shown in FIG. 1C and FIG. 1F (3000×), the height of the projection having three slant faces is approximately 1.6 μm (represented as 1.5 μm to 1.7 μm in the drawings). Note that, FIG. 1A is a perspective view of an electron micrograph of the periphery of the silicon substrate surface having the texture, and FIG. 1D is a perspective view of an electron micrograph of a central part of the silicon substrate surface. Comparative Example 1 [0078] Silicon substrate 100 having orientation (111) is placed on stage 50 of texturing apparatus 10 illustrated in FIGS. 5A and 5B . The area of the surface of silicon substrate 100 is 125 mm×125 mm. The temperature of stage 50 is set to 80° C. After the pressure of reduced-pressure chamber 20 is adjusted to 90 KPa, the etching gas through nozzle 30 is blown on the entire surface of silicon substrate 100 for 75 to 180 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/0 cc/2,000 to 5,000 cc”. [0079] FIGS. 2A and 2B show the shape of surface of the silicon substrate obtained. As shown in FIG. 2A (top view, 10,000×) and FIG. 2B (cross-sectional view, 10,000×), although the surface of the silicon substrate is roughened, the shape is irregular, and no projection having three slant faces is formed. This is because the temperature of the silicon substrate is not maintained at a low temperature. Comparative Example 2 [0080] Silicon substrate 100 having orientation (111) is placed on stage 50 of texturing apparatus 10 illustrated in FIGS. 5A and 5B . The area of the surface of silicon substrate 100 is 125 mm×125 mm. The temperature of stage 50 is set to 25° C. After the pressure of reduced-pressure chamber 20 is adjusted to 90 KPa, the etching gas through nozzle 30 is blown on the entire surface of silicon substrate 100 for 75 to 180 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/0 cc/2,000 to 5,000 cc”. [0081] FIGS. 3A and 3B show the shape of the surface of the silicon substrate obtained. As shown in FIG. 3A (top view, 10,000×) and FIG. 3B (cross-sectional view, 10,000×), although the surface of the silicon substrate is finely roughened, no projection having three slant faces is formed. Example 2 [0082] Silicon substrate 100 having orientation (111) is placed on stage 50 of texturing apparatus 10 illustrated in FIGS. 5A and 5B . The area of the surface of silicon substrate 100 is 125 mm×125 mm. The temperature of stage 50 is set to 25° C. After the pressure of reduced-pressure chamber 20 is adjusted to 90 KPa, the etching gas is blown in two steps. [0083] In the first step, the etching gas through nozzle 30 is blown on the entire surface of silicon substrate 100 for 10 to 30 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/0 cc/2,000 to 10,000 cc”. [0084] In the second step, the etching gas through nozzle 30 is blown on the entire surface of the silicon substrate 100 for 60 to 120 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/500 to 5,000 cc/2,000 to 10,000 cc”. [0085] FIGS. 8A to 8D (electron micrograph, 3000×) show the shape of the surface of the silicon substrate obtained. FIGS. 8A and 8B show the shape of the surface of the silicon substrate after the first step is complete. As shown in FIG. 8A (top view) and FIG. 8B (cross-sectional view), although the surface of the silicon substrate is finely roughened, no projection having three slant faces is formed. [0086] FIGS. 8C and 8D show the shape of the surface of the silicon substrate after the second step is complete. As shown in FIG. 8C (top view) and FIG. 8D (cross-sectional view), projections each having three slant faces and a height of 1.0 μm to 3.0 μm are closely formed on the surface of the silicon substrate. Example 3 [0087] Silicon substrate 100 having orientation (111) is placed on stage 50 of texturing apparatus 10 illustrated in FIGS. 5A and 5B . The area of the surface of silicon substrate 100 is 125 mm×125 mm. The temperature of stage 50 is set to 25° C. After the pressure of reduced-pressure chamber 20 is adjusted to 90 KPa, the etching gas is blown in two steps. [0088] In the first step, the etching gas through nozzle 30 is blown on the entire surface of silicon substrate 100 for 40 to 60 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/0 cc/2,000 to 10,000 cc”. In the second step, the etching gas from nozzle 30 is blown on the entire surface of silicon substrate 100 for 60 to 120 seconds. The composition of the etching gas blown is “ClF 3 /O 2 /N 2 =500 to 1,000 cc/500 to 5,000 cc/2,000 to 10,000 cc”. [0089] FIGS. 9A to 9D (electron micrograph, 3,000×) show the shape of surface of the silicon substrate obtained. FIGS. 9A and 9B show the shape of the surface of the silicon substrate after the first step is complete. As shown in FIG. 9A (top view) and FIG. 9B (cross-sectional view), although the surface of the silicon substrate is finely roughened, no projection having three slant faces is formed. In addition, the surface of the silicon substrate after the first step in Example 3 is rougher than the surface of the silicon substrate after the first step in Example 2 (see FIGS. 8A and 8B ). [0090] FIGS. 9C and 9D show the shape of the surface of the silicon substrate after the second step is complete. As shown in FIG. 9C (top view) and FIG. 9D (cross-sectional view), projections each having three slant faces and a height of 1.0 μm to 6.0 μm are closely formed on the surface of the silicon substrate. The height of the projections formed on the surface of the silicon substrate after the second step in Example 3 is greater than the height of the projections formed on the surface of the silicon substrate after the second step in Example 2 (see FIGS. 8C and 8D ). [0091] The reflectance and the absorbance of the silicon substrate on the textured surface obtained in Example 1 are measured. As Reference Example, the reflectance and absorbance of a non-textured surface of the silicon substrate having orientation (111) are measured. The reflectance and absorbance are measured by a sphere spectrophotometer (U4000, manufactured by Hitachi High-Tech Fielding Corporation). [0092] FIG. 6A is a graph representing reflectance at the non-textured surface of the silicon substrate having orientation (111) (Reference Example) and on the textured surface of the silicon substrate obtained in Example; and FIG. 6B is a graph representing absorbance on the non-textured surface of the silicon substrate having orientation (111) (Reference Example) and on the textured surface of the silicon substrate obtained in Example. [0093] As illustrated in FIG. 6A and FIG. 6B , the reflectance (wavelength of 500 nm to 1,000 nm) on the textured surface of the silicon substrate according to Example 1 is reduced to 20% or lower, and the absorbance (wavelength of 500 nm to 1,000 nm) is increased to 80% or higher. INDUSTRIAL APPLICABILITY [0094] The silicon substrate according to the present invention has a textured surface with low reflectance. In addition, the textured surface is more finely formed than in the conventional technique, and the thickness of the silicon substrate may be reduced. Accordingly, by setting the textured surface as the light-receiving surface, the silicon substrate can be suitably used as a silicon substrate for a solar cell. Accordingly, the silicon substrate contributes to an increased photoelectric conversion rate of a solar cell. REFERENCE SIGNS LIST [0000] 10 Texturing apparatus 20 Reduced-pressure chamber 30 Nozzle that blows etching gas 31 Etching gas supply pipe 40 Nozzle that blows cooling gas 41 Cooling gas supply pipe 50 Stage 100 Silicon substrate 110 Pore 120 Oxidized layer 130 Projection	The present invention addresses the problem of providing a novel silicon substrate having a textured surface by dry-etching the surface of a silicon substrate having (111) orientation and thereby forming a texture thereon. The present invention provides a silicon substrate having (111) orientation, said silicon substrate having a textured surface that includes multiple protrusions which each comprise three slant faces and have heights of 100 to 8000 nm. This process for producing a silicon substrate includes: a step of preparing a silicon substrate having (111) orientation; and a step of blowing an etching gas onto the surface of the silicon substrate, said etching gas containing one or more gases selected from the group consisting of ClF3, XeF2, BrF3, BrF5 and NF3.	8
BACKGROUND OF THE INVENTION The present invention relates to a handling apparatus for groups of thermoformed objects constantly held in a correct axial trim. In the industrial production of thermoformed objects, i.e. containers and lids, by means of a modern thermoforming press, once the moldings of objects have been stacked at a stacking station, the serious problem exists of moving away the already formed stacks with the required rapidity, but without modifying the trim or the axial alignement thereof, within the cycle times of the thermoforming press in order to avoid dead times and to keep a constantly high productivity of the press. As is shown in FIGS. 1 and 2 in the accompanying drawings that illustrate one release or laying phase of a group of stacks 4 of thermoformed objects 5 drawn from a stacking device and located in cages of hooking rods 3 provided with supporting retractable hooks or spikes 6 , laying of the stacks can occur either onto a plane (fixed or movable) p (See FIG. 1 ) or onto a plate p having a series of vertical guides g for locating stacks as shown in FIG. 2 . As a matter of fact, breaking down of the stacks occurs rather frequently since some thermoformed objects 5 can become arranged in an untidy way between the hooking rods 3 during release thereof, which can result in uncomplete release of the stacks or in release and laying of untidy stacks that would create quite serious problems) as will be easily understood, in successive handling operations of the stacks. SUMMARY OF THE INVENTION The main object of the present invention of the present invention is to provide a handling apparatus for groups of stacks which can assure keeping of the correct axial alignment of the single stacks as well as their mutual spacing while being transferred from a stacking or stack storing station to a stack receiving or release station. Another object of the present invention is to provide a handling apparatus for stacks of thermoformed objects that is of high efficiency and practical use so as to be suitable to operate in synchronization and within cycle times of a thermoforming machine. These and other objects which will be better apparent hereinafter are attained by a handling apparatus for groups of thermoformed objects constantly held in a correct axial alignement according to the present invention, which apparatus includes at least one pick up release head having as many receiving seats extending parallel to one another from said head as are the stacks to be handled, and a drive apparatus arranged to move a respective pick up and release head between a stack drawing station and a stack release station of one or more stacks of thermoformed objects and to position it correctly both at the said stack drawing station and at the said release station, and is characterized in that it comprises at least one mobile pusher member arranged to be moved between, and parallel to, the said receiving seats in order to engage at the top thereof the stacks of thermoformed objects located in each receiving seat, and control drive means for each mobile pusher member, thereby following and hold down each stack while the same is being released from its respective receiving seat. Advantageously, an equipped receiving member is provided at the said release station for receiving the stacks released from the picking up head. BRIEF DESCRIPTION OF THE DRAWINGS Further aspects and advantages of the present invention will better appear from the following detailed description of some presently preferred embodiments thereof, given with reference to the accompanying drawings, in which: FIGS. 1 and 2 each show a detail on enlarged scale of a pick up or drawing and transfer head in accordance with the prior art and some typical breakdowns in stacks while being released from the hooking rods; FIG. 3 illustrates a first embodiment of a handling apparatus for groups of stacks of thermoformed objects according to the present invention having rotatable picking up and release head, the stacks being loaded onto a resting surface; FIG. 4 shows a diagrammatic perspective view of a second currently preferred embodiment of a handling apparatus for groups of stacks according to the present invention having a picking up and transfer head for stacks of thermoformed objects, which can move on a straight path for releasing stacks on an equipped plate; FIG. 5 is a diagrammatic perspective view of a detail on an enlarged scale of a pick up head of a stack handling apparatus according to FIGS. 3 and 4 ; FIGS. 6 to 9 show the sequence of laying or releasing a plurality of stacks of thermoformed objects onto a receiving surface by means of a pick up and release head according to FIG. 3 ; FIGS. 10 to 16 are each a diagrammatic perspective view of a pick up head of an apparatus according to FIG. 4 and show the operating sequence of a release and laying of a plurality of stacks of thermoformed objects onto an equipped plate; and FIGS. 17 to 19 illustrate a third embodiment of a handling apparatus for stacks of thermoformed objects, in which the pick up head releases groups of stacks in a substantially horizontal, rather than vertical, direction onto a carry away conveyer for the stacks. In the accompanying drawings the same or similar parts or components have been indicated by the same reference numerals. DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference first to FIGS. 3 to 5 , it will be noted that a handling apparatus for stacks 1 of thermoformed objects according to the present invention comprises a moving pick up-release head 2 having a plate 2 a equipped with six groups of four hooking rods extending downwardly parallel to one another from the plate 2 a . Each group of hooking rods 3 delimits a receiving seat arranged to locate and support a respective stack 4 of thermoformed objects, e.g. lids 5 , as is shown in the drawings. Each hooking rod 3 is provided at its lower free end with a retractable hook 6 , which may be pneumatically remotely controlled to come out from, and retract into, its respective rod, as is well known in the art. In FIG. 3 the plate 2 a is upwardly secured, e.g. bolted, to the free and of a overhanging support arm 7 , which in turn is supported on the top, e.g. keyed, of a vertical output shaft 8 mounted for rotation in a support case 9 , which preferably also locates a reversible motor-reduction gear group (not shown in the drawings, but of any suitable type). The support case also locates a vertically raising-lowering device (not shown in the drawings, e. g. a double acting jack) arranged to cause the overhanging arm 7 , and thus the pick up-release head 2 , to raise and lower vertically. The prearranged and combined motion of rotation and the raising-lowering motion results in the support arm 7 causing, in use, the pick up-release head 2 to move between a picking up station, e.g. at a stacking device 10 (see FIG. 4 ) for picking up a plurality of stacks 4 of thermoformed objects 5 and a release station where the stacks 4 of thermoformed objects are laid, such as onto a flat tape 12 of a tape conveyer 13 shown in FIG. 3 . In the embodiment illustrated in FIG. 4 the plate 2 a of the pick up and release head 2 is secured underneath a support frame 14 which is supported, e.g. in an overhanging fashion, by a pair of sliding guides 15 , that in turn are carried by a fixed U-shaped crosspiece 16 . The frame 14 can be driven to effect to and from movements or strokes between a stack pick up station 10 and a stack release station 17 by means of a linear actuator, e. g. of the type comprising a screw 18 driven by a reversible motor-reduction gear group 19 and nut screw 19 a formed or secured to the frame 14 . Moreover, the plate 2 a can effect straight vertical movements owing to the action of a linear actuator, e. g. comprising a pneumatic double acting cylinder and piston group 20 , which is arranged to lower and lift the plate 2 a at the pick up station 10 and the release station 17 . Both in FIG. 3 and FIG. 4 among the hooking rods 3 there is provided one or more moving pushers 21 , e.g. in the form of a grid or frame mounted or supported in such a way as it can move parallel to the hooking rods 3 in order to engage the top of the stacks 4 of thermoformed objects 5 being located within each group of booking rods 3 . To this end, a suitable drive means is provided, e.g. a pair of double acting pneumatic jacks 23 , arranged to transmit to the pushers a controlled movement to pursue the stacks 4 of thermoformed objects 5 while the same are being released at the stations 12 or 17 . FIGS. 6 to 9 show the operational sequence followed by the pick up and release head 2 illustrated in FIG. 3 while releasing or unloading stacks 4 of thermoformed objects 5 carried by it. Once the head 2 has been transferred (or while being transferred) onto the receiving surface 12 , the pushing frame 21 is moved to rest on top of the stacks 4 of thermoformed objects 5 located in the head 2 , then the plate 2 a is lowered through the arm 7 by the raising-lowering device seated in the case 9 until the tips of the hooking rods 3 are resting on, or very near to, the receiving surface (see FIG. 7 ). At this point, the plate 2 a with its respective hooking rods 3 , owing to the returning action of the raising-lowering device in the case 9 , begins to raise, whereas at the same time the hooks 6 are controlled to retract into their respective hooking rods 3 and the pair of jacks 23 pushes the frame 21 to pursue the stacks 4 and hold them suitably pressed downwards, while the stacks slip off the hooking rods lowing to the raising movement of the plate 2 a to come to rest on the receiving surface 12 and to keep each stack packed until the hooking rods are fully pulled off (see FIG. 8 ); after which the frame 21 is lifted by the jacks 23 (see FIG. 9 ) and the head 2 is moved away from the release station 12 to return to station 10 to be loaded with another group of stacks 4 and to restart the operation cycle. In the embodiment of FIG. 4 the pick up station 10 is constituted by a stacker of any suitable type, e. g. comprising a plate p, vertical guides g extending therefrom and holes 24 formed close to the guides g for temporary receiving and engaging with the tips of the hooking rods 3 of the picking up-release head 2 . Among the guides g stacks 4 of thermoformed objects 5 are obtained in any suitable manner, e.g. owing to the action of a linear actuator 26 , as is well known to a skilled person in the art. The receiving plane at the release or unloading station 17 instead comprises an equipped plate 30 , which can have vertical guides g as plate g at the pick up station 10 and has a vertically movable bearing frame or grid 31 and a linear actuator for the frame 31 , e. g. comprising a pair of pneumatic jacks 32 whose piston rod is secured to the frame 31 so as to cause the same to effect controlled lifting-lowering strokes. The operation sequence of the handling apparatus according to the present invention, framed as shown in FIG. 4 , is illustrated in FIGS. 10 to 16 according to distinct operational ways, will explained hereinbelow. The head 2 is vertically transferred above the equipped plate 30 located at the release or unloading station 17 . The frame 31 , while the head 2 is being transferred or immediately after the same has arrived above the plate 30 , is lifted towards the head 2 , as is shown in FIG. 10 . According to a first way of unloading (see FIGS. 10 to 13 ) the head 2 carries lengths 4 a of stacks to be unloaded onto the plate 30 , and thus the frame 31 is moved to a lifted position to receive the lengths 4 a , whereas the head 2 , within which in the mean time the frame 21 has moved to a rest position onto the stacks lengths 4 a , is lowered by the jack 20 until the lengths 4 a rest onto the frame 31 underneath (see FIG. 11 ). At this point the frame 31 is lowered towards an intermediate position, whereas the jacks 23 push the frame 21 downwards so as to hold down the stack lengths 4 a well packed (FIG. 12 ), after which the head 2 is raised and can return to the pick up station 10 to be loaded with a second group of stack lengths 4 b and to be then transferred, owing to the drive action of the motor 19 , above the plate 30 (FIG. 13 ), where in the mean times the frame 31 is in a standby condition in its intermediate position corresponding to the height of the coming lengths 4 b which are then unloaded with the above described procedure onto the lengths 4 a under the pushing action of the frame 21 so as to complete the stacks 4 (FIG. 14 ). According to a further way of carrying out unloading or release operations, the head 2 is loaded with complete stacks 4 and unloads them in a single operation, as shown in FIG. 14 , always with the pushing action of the upper frame 21 in the head 2 and the frame 31 onto the receiving plate 30 , which in each case is lifted from the plate 30 , as shown in FIG. 10 , to receive the coming stacks 4 and lower them onto the plate 30 . Once the complete stacks 4 are unloaded onto the frame 31 by being pushed by the upper frame 21 , the head 2 is lifted, whereas the frame 21 holds down the stacks while being further lowered together with the lower frame 31 , that in the mean time comes to rest onto the plate 30 while the hooking rods 3 slip off the stacks (FIG. 15 ). Finally, the frame 21 is lifted and leaves the stacks 4 and the head 2 can move away from the release station 17 , thus leaving on the plate 30 stacks perfectly axially aligned and ready for subsequent handling operations (FIG. 16 ). It will be noted that owing to the presence of the frame or grid 21 , even in the case in which gravity does not suffice to ensure unloading by fall of all the thermoformed objects in a stack 4 , all the thermoformed objects 5 are unloaded from the head 2 in any circumstance and, since they are permanently held down well packed together during the unloading operation, the stacks 4 cannot split up or become otherwise misaligned. FIGS. 17 to 19 show a handling apparatus according to the present invention having a pick up-release head 2 with a plate 2 a laying in a transverse (vertical) plane rather than a horizontal one, as in the above described embodiments, in order to carry out loading and unloading of groups of stacks of thermoformed objects in a direction which differs from the vertical one, and thus even without taking advantage of the gravity for unloading the stacks. More particularly, the plate 2 a is equipped with a multiplicity of pairs of guides 40 delimiting a sliding receiving seat for the stacks 4 and are equal in number to the stacks to be received therein. The guides 40 extend perpendicularly from a face of the plate 2 a and a pusher, formed by a cross bar 21 driven by a pair of double acting jacks 23 , is arranged to move parallel to them. The unloading or release station is constituted e. g. by a tape conveyer 13 having a tape 12 provided with parallel partition sectors 12 a delimiting (horizontal) cradles for the stacks 4 . A resting and guide element, e. g. constituted by a bar 31 extending parallel to the bar 21 (when the latter is in its unloading position) is mounted on the conveyer 13 . The bar 31 is supported by a pair of sliding (horizontal) guides 41 and is secured to the piston rod end of a double acting jack 42 . During the unloading operation, the head 2 is moved with its receiving seats in alignement with an equal number of cradles on the conveyer 13 , the pushing bar is brought to rest against the stacks 4 loaded in the head 2 , after which the pusher 21 and the bar 31 are moved in unison so as to keep the stacks 4 well packed and transfer them onto the conveyer 13 . The latter has downstream thereof a pair of fixed sliding guides 42 and 43 extending in the feeding direction of the tape 12 so as constantly to keep the stacks 4 well packed and axially aligned. During unloading in fact the pusher 21 moves forwards until its front is coplanar with the inner face of the guide 42 , whereas at the same time the bar 31 moves backwards until its front face is coplanar with the inner face of the guide 43 . The bars 21 and 31 remain in this aligned position with their respective fixed guide 42 , 43 until the tape 12 has moved forward to such an extent that al the stacks 4 unloaded thereon are abutting against the guides 42 and 43 , after which the pusher 21 moves back and the head 2 can return to be loaded with stacks 4 to start a new operating cycle. The disclosure in Italian patent application no. VR2001A000017 filed on Feb. 15, 2001 from which priority is claimed is incorporated herein by reference.	A handling apparatus for groups of thermoformed object constantly held in a correct axial alignment. The apparatus include at least one picking up and release head having as many receiving seats extending parallel to one another from the head as are the stacks to be handled, and a drive apparatus arranged to move a respective pick up and release head between a stack pick up station and a stack release station of one or more stacks of thermoformed objects and to position it correctly both at the stack pick up station and at the stack release station. At least one mobile pusher member is arranged to engage the stacks of thermoformed objects located in each receiving sear, and control drive apparatus for each mobile pusher member to follow and hold down each stack while each stack is being released from its respective receiving seat.	1
FIELD OF THE INVENTION AND RELATED ART The present invention relates to an element chip, which comprises an energy generating element for generating ejection energy to be used for ejecting recording liquid (ink or the like) in the form of a flying liquid droplet from an ejection outlet (orifice), and is employed in an ink jet head installed in an ink jet recording apparatus, which generates records by adhering the ejected liquid droplets to the recording medium. In particular, the present invention relates to such an element chip in which plural energy generating elements for generating the ink ejection energy to be used for ejecting the ink are arranged in a predetermined manner. The present invention also relates to an ink jet head, in which plural ejection energy generating elements are arranged in a predetermined manner, and an ink jet apparatus comprising such a head. The ink jet recording method is a recording method in which ink (recording liquid) is ejected from an orifice, or orifices, of a recording head, so that the ejected ink is adhered to recording medium, such as paper, to create a record. This method has various advantages. For example, it generates only an extremely small amount of noise, and can record at a high speed. In addition, it can record on plain paper and it does not require dedicated paper with special composition. Therefore, various types of ink jet recording head have been developed. Among them, there is a type which applies thermal energy to the ink to eject it from the orifice. This type of ink jet head is produced in the following manner. The electrothermal transducers and electrodes are formed on a substrate, and are covered with a protective film as needed. Then, a top plate, in which liquid paths and a liquid chamber are formed, is joined with the substrate. The ejection energy for ejecting the ink from this type of recording head is generated by the electrothermal transducer comprising a pair of electrodes, and a heat generating resistor element disposed between the pair of electrodes. More specifically, an electric signal is applied to the electrode to cause the heat generating resistor element to generate heat. As heat is generated by the heat generating resistor, the ink adjacent to the heat generating resistor disposed within the ink path is instantaneously heated, generating bubbles. As the volume of each bubble quickly grows and contracts, the ink is ejected in the form of a liquid droplet. When a recording head, which is structured as described in the foregoing, and is capable of accommodating an A3 paper, is wanted, plural element chips, in which a predetermined number of heat generating resistor elements are arranged at a predetermined pitch, are employed. More specifically, the plural element chips are precisely aligned on a supporting member, which has a width correspondent to the recording width, so that the recording width for A3 paper can be entirely covered with the aligned heat generating resistor elements, at the same pitch as the heat generating resistor element pitch in each of the element chips. However, the structure described above suffers from the following shortcoming. That is, in order to make the heat generating resistor element pitch, between the heat generating resistor elements located at each end of two adjacent element chips, substantially equal to the predetermined element pitch in each chip, both ends of each element chip must be cut at a point extremely close to a heat generating resistor element, during the element chip production. As a result, the portions of the element chip, or, in the worst case, the heat generating resistor element itself, is liable to be damaged by chipping and/or shell cracking that could occur during the cutting process. SUMMARY OF THE INVENTION According to the present invention, which was made to eliminate the shortcoming described above, the heat generating resistor elements located near the end, relative to the alignment direction, of each element chip, are aligned at a smaller pitch than the normal (main) pitch for the heat generating resistor elements located across the middle of the same element chip; that is, they are inwardly displaced, relative to the end of each element chip. With such placement of the heat generating resistor elements, the margin, which is reserved for cutting the substrate to separate each element chip, can be increased to prevent the heat generating resistor element from being damaged by chipping, shell cracking, and the like. Further, when the above structure is not satisfactory, a stepped portion may be formed between the heat generating resistor element adjacent to the cutting margin, and the cutting margin, so that the effects of the aforementioned structure can be enhanced. These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of an embodiment of the present invention. FIG. 2 is a schematic view of another embodiment of the present invention. FIG. 3 is a schematic view of a further embodiment of the present invention. FIG. 4 is a schematic sectional view of the embodiment of the present invention, illustrating a state of chipping which occurs when a substrate structured according to the present invention is cut. FIG. 5 is a schematic view of a conventional element chip, illustrating a state of chipping which occurs when a conventionally structured element chip is cut. FIG. 6 is a schematic view of another state of chipping which occurs when the conventionally structured element chip is cut. FIG. 7 is an exploded perspective view of an widened head, in which plural element chips in accordance with the present invention are aligned in a predetermined manner. FIG. 8 is a conceptual view of an ink jet recording apparatus employing a full-line head in accordance with the present invention. FIG. 9 is a perspective view of an ink jet recording apparatus employing the ink jet head in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the embodiments of the present invention will be described with reference to the drawings. The phrase, "on the substrate," which is used in the following embodiments, means "on the substrate," as well as "immediately below the plane of the substrate surface." Even though ink is used as the liquid to be ejected in the following embodiments, the liquid to be ejected is not limited to ink; any liquid is usable as long as it can be ejected by the ejection head in accordance with the present invention. FIG. 1 is a schematic view of an embodiment of the present invention. A reference numeral 11 designates a heat generating resistor element (ejection heater) as an ejection energy generating member. Each ejection heater comprises a heat generating resistor layer 12, and a pair of electrodes (unillustrated); and generates heat as a voltage is applied to the heat generating resistor layer 12 through the pair of electrodes. One of the electrodes is connected to an independent electrode (unillustrated), and the other is connected to a common electrode (unillustrated). The heat generating resistor elements 11 are aligned on the element substrate at a predetermined pitch P1, except that the first and last heat generating resistor elements of each element chip, that is, the heat generating resistor element located at each end, in the alignment direction, of each element chip, is aligned at a shorter pitch P2 than those segments located between the first and last elements. Further, counting from left to right in FIG. 1, the distance between the last element 11c of the first element chip, and the first element 11d of the next element chip is rendered greater than P1. Lastly, the distance between the second element 11b, counting from right to left, of the first element chip, and the second segment 11e, counting from left to right, of the next element chip, is set at a distance of approximately 3×P1. Therefore, plural element chips can be aligned in a straight line, so that the alignment pitch for the heat generating resistor elements can be rendered substantially uniform across the entire length of the alignment. FIG. 2 is a schematic view of another embodiment of the present invention, in which three different pitches (P2, P3 and P4), which are shorter than the normal alignment pitch P1, are employed. In this drawing, the relationship among the different pitches is: P1>P2>P3>P4. However, the relationship among the different pitches is not limited to the above. In other words, such factors as the number of alignment pitches different from the regular pitch P1, the positional relationship among the different pitches, and the like, may be optionally combined to obtain the same effect as the present invention. In the embodiment illustrated in FIG. 1, the distance between the second ejection heater, counting from left to right, of one element chip, and the second ejection heater, counting from right to left, of the next element chip, is set at approximately three times the pitch for the ejection heaters located at the center portion of the element chip. In the embodiment illustrated in FIG. 2, the distance between the third ejection heater, counting from left to right, of one element chip, and the third ejection heater, counting from right to left, of the next element chip, is set at approximately seven times the pitch for the ejection heaters located at the center portion of the element chip. With the arrangements described above, the element chip can be cut at a point close to the ejection heater, without damaging it; therefore, even when plural element chips are continuously aligned in a straight line, the ejection heater intervals can be rendered generally uniform. The ejection heater intervals are not limited to those described above. Needless to say, the distance between the second ejection heaters of two adjacent element chips, counting away from the joint, may be set at approximately five times the interval between the adjacent ejection heaters located at the central portion of each element chip. In the preceding embodiment, the interval between the adjacent two ejection heaters located near each end of each element chip is adjusted. However, when only two element chips are aligned, the ejection heater interval may be adjusted only at the element chip end on the joint side. FIG. 3 is a schematic section (at A--A line in FIG. 1) of the embodiment of the present invention, illustrating a stepped portion 19 for preventing the advance of the crack, such as pitching or shell crack, which occurs while the substrate is cut. The stepped portion 19 can be formed using, for example, the same manufacturing step and the same material (Al, Cu or the like) for wiring electrode, without increasing the number of manufacturing steps. If cost is not a concern, the stepped portion 19 may be formed of a separate material (organic material such as polyimede). FIG. 4 is a schematic sectional view of the embodiment of the present invention, illustrating how the advance of the crack is prevented while the substrate is cut. Even if a crack 17 occurs as the chip substrate 10 is cut across a margin 16, the advance of the crack can be stopped at the stepped portion 19. FIGS. 5 and 6 are schematic sections of the conventional chip structure, illustrating how the crack advances while the substrate is cut. As is evident from FIGS. 5 and 6, when the stepped portion 19 for crack advance prevention illustrated in FIG. 4 is not provided, the crack spreads to affect the elements formed on the chip substrate. The recording head described above can be produced following the steps described below. To begin with, a 1-3 μm thick SiO 2 film as a heat storage layer 13 is formed on a Si wafer, using thermal oxidation. Next, a 400-2,000 Å thick HfB 2 film which becomes the heat generating resistor layer, a 10-100 Å thick Ti film which becomes an adhesion enhancement layer, and a 3,000-10,000 Å thick Al (wiring electrode material), are deposited in this order by sputtering. Then, the heat generating resistors, electrodes, and the like, of desired patterns are formed by photolithography. Next, a 1-2 μm thick film of SiO 2 or Si 3 N 4 as a protective layer 14 is formed by CVD or sputtering. Thereafter, a 2,000-5,000 Å thick Ta film as a cavitation resistance layer 15 is deposited by sputtering. Then, the desired patterns are formed by photolithography to complete the element chip 10. The element chips 10 are precisely aligned on a supporting member 18 (for example, Al substrate) with excellent heat radiating properties, and fixed thereto by die bonding. Lastly, a glass plate (unillustrated), which has grooves for forming at least the ink paths and orifices, is aligned on the chip substrate, so that the groove portions for forming the ink paths are properly located in relation to the heat generating portion formed on the chip substrate, and is glued thereto. Instead, the walls for forming at least the ink paths and ejection orifices, may be formed on the chip substrate by photolithography which uses photosensitive resin or the like, and then, the walls may be covered to complete the recording head. In the preceding embodiment, two element chips are aligned. However, a much larger number of element chips may be aligned to lengthen the recording head. FIG. 7 illustrates such an example, in which plural element chips 100, in which plural heat generating resistors 101 are aligned in a straight line, are aligned in a straight line on a supporting member (base plate) of aluminum (Al) or the like. Each element chip is connected to the contact pad of the wiring chip through a connector 102. The top plate 200, which is grooved to form an ink path for each heat generating resistor, is attached to the plural element chips aligned as described above, to complete a wider head. FIG. 8 is a schematic perspective view of a so-called full-line type recording head, the width of which corresponds to the recording width of the recording medium, and a recording apparatus, in which the full-line type recording head is mounted. The present invention displays the most outstanding effects when applied to the full-line recording head illustrated in FIG. 8. Referring to FIG. 8, a reference numeral 6 designates a full-line recording head. The ink is ejected from this recording head, in response to signals supplied from driving signal supplying means (unillustrated), toward a recording medium 80 such as paper or fabric conveyed by a conveyer roller 90, whereby recording is made on the recording medium 80. According to the present invention, even when a widened extended recording head such as the full-line head is employed, high quality recording can be easily made. FIG. 9 shows such a recording apparatus that employs a small recording head comprising only one or two element chips. The recording apparatus illustrated in FIG. 9 comprises a recording head cartridge constituted of an independently exchangeable ink container 70 and an independently exchangeable recording head portion 60. It also is comprises: a motor 81 as a driving power source, which drives the carriage; a conveyer roller 90 for conveying a recording medium 80; and a carriage shaft 85 for transmitting the driving force from the driving power source to the carriage. Further, it comprises signal supplying means for supplying an ink ejection signal to the recording head. As described above, according to the present invention, even in the case of manufacturing a small element chip which requires cutting the chip substrate at a point close to the region in which the heat generating resistors are disposed, no damage occurs to the heat generating resistor. Therefore, even when plural element chips are aligned in a straight line, the heat generating resistor pitch can be rendered substantially uniform across the entire length of the alignment, satisfying the condition for the heat generating resistor alignment. As is evident from the foregoing, according to the present invention, even when plural element chips are employed, the ejection heater pitch can be rendered substantially uniform across the combined length of the plural chips. Further, the present invention also enjoys an advantage in that the element chip in accordance with the present invention can be manufactured using the conventional process, without a need for increasing the number of manufacturing steps; therefore there is no cost increase. Further, when the chip substrate is cut to yield element chips, it can be cut at a point close to the heat generating resistor; therefore, plural element chips can be aligned to produce a wider recording head. Consequently, the wider recording head can be inexpensively produced with extremely high yield. When the head described is employed, an ink jet apparatus capable of recording high quality images at a high speed can be inexpensively produced. While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.	A liquid jet element substrate having a plurality of ejection energy generating elements for generating ejection energy for ejecting liquid, arranged in an array in a direction at predetermined intervals, wherein an interval between the ejection energy generating element at an end, in the direction of the array, and the ejection energy generating element adjacent thereto is smaller than an interval between adjacent central ejection energy generating elements.	1
TECHNICAL FIELD The present invention relates generally to fuel tanks for vehicles and, more particularly, to a fuel strainer assembly for a fuel tank of a vehicle. BACKGROUND OF THE INVENTION It is known to provide a fuel tank for a fuel system in a vehicle to hold fuel to be used by an engine of the vehicle. It is also known to provide an electric fuel pump in the fuel tank to pump fuel from the fuel tank to the engine. In-tank electric fuel pumps typically require a filter to remove particulate contaminants from the fuel prior to entering the fuel pump. This pre-filtration is commonly accomplished by connecting a fuel strainer assembly to an inlet of the fuel pump. However, this connection interface must secure the mating parts for a life of the fuel pump. One known connection is a press fit connection between an outside diameter of a snout extending from an inlet body of the fuel pump and an inside diameter of a connector body integral to the fuel strainer assembly. Another known connection secures the fuel strainer assembly to the inlet of the fuel pump using a post extending from the inlet body and a pal nut fastener to retain the fuel strainer assembly. However, both of these connections require a feature to be added to the inlet body (i.e., a snout or a post) of the fuel pump. As a result, these features add unnecessary complexity to the inlet body of the fuel pump and are not production feasible for a manufacturing process (i.e. compression molding). Therefore, it is desirable to provide a new fuel strainer assembly for a fuel tank in a vehicle that has a connection to attach a fuel strainer to an inlet of the fuel pump. It is also desirable to provide a fuel strainer assembly for a fuel tank in a vehicle that eliminates additional parts for connection of the fuel strainer to the inlet of the fuel pump. It is further desirable to provide a fuel strainer assembly for a fuel tank in a vehicle that provides orientation and anti-rotation of the fuel strainer relative to the inlet of the fuel pump. SUMMARY OF THE INVENTION It is, therefore, one object of the present invention to provide a fuel strainer assembly for a fuel tank in a vehicle. It is another object of the present invention to provide a fuel strainer assembly for a fuel tank in a vehicle that connects a fuel strainer to an inlet of a fuel pump without adding additional parts. To achieve the foregoing objects, the present invention is a fuel strainer assembly including a filtration member and an inlet connector connected to the filtration member for connection to an inlet of a fuel pump. The fuel strainer assembly also includes a push pad connected to the filtration member. The fuel strainer assembly further includes a compression retainer operatively supported by the push pad to engage the inlet connector to cause an interference fit between the inlet connector and the inlet of the fuel pump to secure the inlet connector to the fuel pump. One advantage of the present invention is that a new fuel strainer assembly is provided for a fuel tank in a vehicle. Another advantage of the present invention is that the fuel strainer assembly allows contaminant wear resistant materials to be compression molded. Yet another advantage of the present invention is that the fuel strainer assembly allows a fuel strainer to be attached to a fuel pump without the addition of extra features to an inlet body of the fuel pump and eliminates additional parts like a pal nut or retainer. Still another advantage of the present invention is that the fuel strainer assembly provides a mechanism for radial orientation and anti-rotation because the location of the fuel strainer is controlled by the components and not the assembly tooling. Other objects, features, and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary elevational view of a fuel strainer assembly, according to the present invention, illustrated in operational relationship with a fuel tank. FIG. 2 is a fragmentary elevational view of the fuel strainer assembly of FIG. 1 illustrating pre-assembly. FIG. 3 is a view similar to FIG. 2 of the fuel strainer assembly of FIG. 1 illustrating final assembly. FIG. 4 is a fragmentary elevational view of another embodiment, according to the present invention, of the fuel strainer assembly of FIG. 1 illustrating pre-assembly. FIG. 5 is a view similar to FIG. 4 of the fuel strainer assembly of FIG. 4 illustrating partial assembly. FIG. 6 is a view similar to FIG. 4 of the fuel strainer assembly of FIG. 4 illustrating final assembly. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and in particular FIGS. 1 and 2, one embodiment of a fuel strainer assembly 10 , according to the present invention, is shown for a fuel tank, generally indicated at 12 , in a vehicle (not shown). The fuel tank 12 includes a fuel-sending unit, generally indicated at 14 , disposed therein having a removable cover 16 sealed to the top of the fuel tank 12 with an electrical connector 18 and a fuel line connector 20 . The fuel-sending unit 14 also includes an electrical fuel pump 24 . The fuel-sending unit 14 includes a fuel tube 26 connected to the fuel pump 24 and connected to the fuel line connector 20 by a coupler 28 . The fuel strainer assembly 10 is connected to the fuel pump 24 and is positioned close to a bottom of the fuel tank 12 . The fuel tank 12 is formed of a metal material or plastic material. It should be appreciated that the fuel strainer assembly 10 may be connected to a fuel module (not shown) or directly to the fuel pump 24 . It should also be appreciated that electrical wires 29 interconnect the electrical connector 18 and the fuel pump 24 . Referring to FIGS. 2 and 3, the fuel pump 24 has an inlet body 30 with an inlet 32 at a bottom thereof. The inlet 32 is a counter-bore extending axially into the inlet body 30 . The inlet body 30 also has a recess or groove 34 spaced radially from and adjacent to the inlet 32 for a function to be described. The fuel pump 24 also has an outer shell 36 that contains the inlet body 30 and secures the inlet body 30 in the axial direction using a rolled lip 38 . It should be appreciated that the lip 38 of the outer shell 36 overlaps a portion of the inlet body 30 . It should also be appreciated that the inlet body 30 may be formed by a conventional process such as a compression molding process. Referring to FIGS. 1 through 3, the fuel strainer assembly 10 includes a fuel strainer 40 extending longitudinally. The fuel strainer 40 is generally rectangular in shape, but may be any suitable shape. The fuel strainer 40 has an inlet connector 42 that fits into the inlet 32 of the inlet body 30 of the fuel pump 24 . The inlet connector 42 is a tubular member made of a rigid material such as metal or plastic, preferably nylon or acetal. The inlet connector 42 has an annular flange 44 extending radially from one end thereof. The annular flange 44 may include a small nib or tab 46 disposed in the recess 34 to act as an anti-rotation feature for the assembly 10 . It should be appreciated that the inlet connector 42 is integral, unitary, and formed as one-piece. The fuel strainer 40 includes a filtration member 48 connected to the inlet connector 42 . The filtration member 48 is fabricated from a mesh or fibrous filtering material made of a plastic material, preferably nylon, to allow fuel to pass therethrough to the fuel pump 24 , but prevent certain contaminants from passing therethrough to the fuel pump 24 . The filtration member 48 has a particle retention rating of approximately thirty (30) microns to approximately eighty (80) microns. The filtration member 48 may be one or more layers connected to the connector 42 by conventional means. The fuel strainer 40 also includes a push pad 50 connected to the filtration member 48 at a bottom thereof and aligned with the inlet connector 42 . The push pad 50 is an annular member made of a rigid material such as metal or plastic, preferably nylon or acetal. The push pad 50 has a central cavity 52 for a function to be described. The push pad 50 also has an annular flange 54 extending radially from one end thereof. It should be appreciated that the push pad 50 is integral, unitary, and formed as one-piece. The fuel strainer assembly 10 also includes a locking mechanism such as a compression retainer 56 to lock the inlet connector 32 to the fuel pump 24 . The compression retainer 56 is a tubular member made of a rigid material such as metal, preferably steel. The compression retainer 56 has an annular flange 58 extending radially from one end thereof. The compression retainer 56 is disposed within the filtration member 44 and sets on the push pad 50 . The compression retainer 56 has a slight draft complementary to an inside diameter of the inlet connector 42 . It should be appreciated that the compression retainer 56 is disposed inside the fuel retainer 40 and sets freely inside the inside diameter of the inlet connector 42 . It should also be appreciated that the push pad 50 prevents the compression retainer 56 from disengaging the inside diameter of the inlet connector 42 . To assemble the fuel strainer assembly 10 to the fuel pump 24 , the inlet connector 42 is disposed axially in the inlet 32 of the inlet body 30 . During insertion of the inlet connector 42 into the inlet 32 of the inlet body 30 of the fuel pump 24 , the inlet connector 42 engages with the inlet 32 without interference. The push pad 50 is then pressed against the compression retainer 56 . As the insertion depth of the compression retainer 56 increases, the inlet connector 42 compresses against the inside surface of the inlet 28 , creating an extremely secure interference fit and preventing the fuel strainer 40 from disengaging from the fuel pump 24 . It should be appreciated that fuel strainer 40 is retained with an axial insertion or push-on force (no rotation) It should also be appreciated that the inlet connector 42 and compression retainer 56 reliably secure the fuel strainer 40 to the inlet body 30 and the slot 34 and tab 46 locate a radial position of the fuel strainer 40 , adding an anti-rotation feature to the assembly 10 . It should further be appreciated that after the compression retainer 56 is in place, the push pad 50 falls down a distance such as three to four millimeters as illustrated by the phantom lines in FIG. 3 . Referring to FIGS. 4 through 6, another embodiment, according to the present invention, of the fuel strainer assembly 10 is shown. Like parts of the fuel strainer assembly 10 and fuel pump 24 have like reference numerals increased by one hundred (100). In this embodiment, the fuel strainer assembly 110 includes the fuel strainer 140 having the inlet connector 142 , filtration member 148 , and push pad 150 . The fuel strainer assembly 110 eliminates the tab on the inlet connector 142 . The inlet connector 142 has a slight draft or inclined inner surface 143 molded therein and the compression retainer 156 has a slight draft or inclined outer surface 157 , allowing for the inlet connector 142 to be compressed against the entire inner surface 143 of the inlet 132 of the inlet body 130 . The inlet connector 142 also has a lower cavity 160 extending axially therein to receive a portion of the push pad 150 . Additionally, in this embodiment, the fuel pump 124 includes the inlet body 130 having the inlet 132 and the outer shell 136 having the lip 138 . The inlet body 130 is preferably made of a powered metal material. To assemble the fuel strainer assembly 110 to the fuel pump 124 , the inlet connector 142 is disposed axially in the inlet 132 of the inlet body 130 . During installation of the inlet connector 142 into the inlet 132 of the inlet body 130 of the fuel pump 124 , the inlet connector 142 engages with inlet 132 without interference. The push pad 150 is then pressed against the compression retainer 156 . As the insertion depth of the compression retainer 156 increases, the inlet connector 142 compresses against the surface of the inlet 128 , creating an extremely secure interference fit and preventing the fuel strainer 140 from disengaging from the fuel pump 124 . It should also be appreciated that the inlet connector 142 and compression retainer 156 reliably secure the fuel strainer 140 to the inlet body 130 . It should further be appreciated that after the compression retainer 156 is in place the push pad 150 falls down a distance such as three to four millimeters as illustrated in FIG. 6 . The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.	A fuel strainer assembly includes a filtration member and an inlet connector connected to the filtration member for connection to an inlet of a fuel pump. The fuel strainer assembly also includes a push pad connected to the filtration member. The fuel strainer assembly further includes a compression retainer operatively supported by the push pad to engage the inlet connector to cause an interference fit between the inlet connector and the inlet of the fuel pump to secure the inlet connector to the fuel pump.	1
FIELD [0001] The present invention generally relates to sectional wood overhead doors used to create access to building interiors in residential and commercial applications. More specifically, the present invention relates to sectional wood overhead doors having inset or internal reinforcing members. BACKGROUND [0002] Sectional overhead doors are frequently used to create access to building interiors in residential and commercial applications. Such doors are commonly referred to as “overhead garage doors”, or merely “garage doors”. [0003] In today's society, numerous people are installing custom garage doors, particularly doors that have architectural features, such as sections to provide the appearance of double-swing doors or other old-time architectural structure. [0004] To provide a more authentic appearing door than possible with steel or fiberglass, some of today's overhead doors are returning to the original material; that is, they are made from wood. Wood has advantages over steel or fiberglass, by providing a door that can be readily painted or stained or further customized as desired, and by providing a façade that weathers, increasing the old-time authentic appearance. Large wood doors, even though generally solid however, are less strong and stable than steel and fiberglass doors, and have been known to twist or bend under certain uses. [0005] Door manufactures have increased the lateral and torsional strength of wood doors by providing a reinforcing member along the surface of the wood door, generally on the interior side when the door in installed. These reinforcing members are commonly referred to as struts, U-bars, braces, or the like. [0006] Although the reinforcing member, such as a strut, is structurally sound and provides the desired increase in strength, the visual appearance of the door is lacking. Improvements are desired. SUMMARY [0007] The present invention provides a wood garage door, typically solid wood, that incorporates aesthetic features while meeting structural standards. In particular, the present invention generally relates to sectional wood overhead doors used to create access to building interiors in residential and commercial applications. The inventive doors include an inset lateral reinforcing member, with the reinforcing member being inset at least partially into the door. No portion of the reinforcing member extends out from or above a surface of the door. [0008] When the door is installed for use, the inset reinforcing members do not extend past the interior surface of the door. Preferably, the inset reinforcing members are not visible or otherwise discernable by one looking at or otherwise examining the internal surface of the door. [0009] Within the application, the term “strut” is used to represent the reinforcing member. The term “strut” is interchangeable with other common terms for reinforcing members such as brace and U-bar. [0010] In one particular aspect, the invention is to a wood door, such as a garage door, that has a plurality of sections hingedly connected, each of the sections comprising a wooden internal frame having a first side, an opposite second side, a first side edge and an opposite second side edge. A first layer is present over the first side and a second layer is present over the second side, each of the first layer and the second layer covering the internal frame. At least one of the sections has an inset strut extending laterally across the section between the first side edge and the second side edge, with no portion of the inset strut extending above a surface of the first layer. The inset strut could be recessed into the first layer or present between the frame and the first layer. The inset strut could have a T-shape. Additionally or alternately, the inset strut could be composed of two pieces, and those two pieces could be L-shaped. More than one of the sections could include an inset strut; for example, two or more, or three or more sections could include an inset strut. When installed, the first layer forms the interior surface of the door. [0011] In another particular aspect, the invention is to a section, such as for a garage door, the section having a wooden internal frame having a first side, an opposite second side, a first side edge and an opposite second side edge. A first layer is present over the first side and a second layer is present over the second side, each of the first layer and the second layer covering the internal frame. An inset strut extends laterally across the section between the first side edge and the second side edge, with no portion of the inset strut extending above a surface of the first layer. The inset strut could be recessed into the first layer or present between the frame and the first layer. The inset strut could have a T-shape. Additionally or alternately, the inset strut could be composed of two pieces, and those two pieces could be L-shaped. The section can be combined with additional sections, either having an inset strut or not, to form a door. When installed, the first layer forms the interior surface of the door. [0012] A more complete appreciation of the present invention and its scope may be obtained from the accompanying drawings that are briefly described below, from the following detailed descriptions of presently preferred embodiments of the invention and from the appended claims. BRIEF DESCRIPTION OF THE DRAWING [0013] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawing, in which: [0014] FIG. 1 is a schematic, front plan view of a house with a garage having two garage doors installed thereon; [0015] FIG. 2 is a plan view of the front, exterior side of a garage door according to the present invention, similar to those illustrated in FIG. 1 ; [0016] FIG. 3 is a plan view of the back, interior side of a prior art garage door; [0017] FIG. 4 is a plan view of the back, interior side of the garage door of FIG. 2 , according to the present invention; [0018] FIG. 5 is an end view of the garage door of FIG. 4 ; [0019] FIG. 6 is an interior elevation of the interior of the garage door according to the present invention; [0020] FIG. 6A is one section from the door shown in FIG. 6 ; [0021] FIG. 7 is a front plan view of a reinforcing strut for the garage door according to the present invention; [0022] FIG. 8 is an end plan view of the reinforcing strut of FIG. 7 ; [0023] FIG. 9 is a front plan view of a top reinforcing member of the garage door according to the present invention; [0024] FIG. 10 is an end plan view of the top reinforcing member of FIG. 9 ; and [0025] FIG. 11 is a cross-sectional view of a portion of the garage door, taken along line 11 - 11 of FIG. 6 , showing a reinforcing strut and a top reinforcing member installed in the door. [0026] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawing and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION [0027] In the following description of preferred embodiments of the present invention, reference is made to the accompanying drawing that forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. [0028] Referring to FIG. 1 , a typical, residential house 5 is shown having a garage 6 with side-by-side single garage doors 10 , specifically, doors 10 A and 10 B. Although garage 6 is illustrated as attached to house 5 , garage 6 with doors 10 A, 10 B could be a detached garage. Also, although garage 6 is illustrated with two doors 10 , garage 6 could have one door 10 , three doors 10 , or more. [0029] Referring to FIG. 2 , garage door 10 is illustrated as seen from the exterior of garage 6 . That is, in FIG. 2 , the exterior side or surface 12 of door 10 is seen. Door 10 has a first side edge 16 , and opposite side edge 18 , a top edge 17 and a bottom edge 19 . [0030] Typical sizes for door 10 , if a single garage door, include 8 ft wide by 7 ft high (96 inches×84 inches), 8 ft by 8 ft (96 inches×96 inches), and 9 ft by 8 ft (108 inches×96 inches). Door 10 as wide as 10½ ft (126 inches) is also possible. Double garage doors are also within the scope of this invention. Typical sizes for door 10 , if a double garage door, include 16 ft wide by 7 ft high (192 inches×84 inches), 16 ft wide by 8 ft high (192 inches×by 96 inches), and 18 ft wide by 8 ft high (216 inches×96 inches). It is understood that other sizes, whether single doors, double doors, or special sizes, are possible and within the scope of this invention. The various heights and numbers of the sections that make up door 10 are adjusted to provide the desired door height. [0031] Door 10 can have an ornamental façade on exterior surface 12 . In this illustrated embodiment of FIG. 2 , the façade includes twelve raised panels and two windows 20 . Other façades for door 10 are known and are suitable for use with the present invention. For example, other suitable façades include sections with flat panels, three or four windows, and v-groove. See also, for example, U.S. Pat. Nos. Des. 378,853, Des. 378,421, Des. 380,053, Des. 382.065, Des. 382,066, Des. 382,067, Des. 383,551, Des. 397,446, Des. 397,447, and 6,446,695, all which are incorporated herein by reference and which disclose various façade configurations that are suitable for door 10 . One popular façade is that of an old fashioned-looking carriage door, such as a double-swing door. [0032] Door 10 is an overhead door, intended to be supported by and move on side-mounted tracks or rails, as are well known. Door 10 is composed of multiple sections 22 ; particularly, door 10 in FIG. 2 has bottom section 22 A, an internal section such as second section 22 B, another internal section such as third section 22 C, and fourth or top section 22 D. Top section 22 D includes windows 20 and is a windowed section 22 D; it is understood that having a windowed section is optional. [0033] Door 10 is a “wood” door, meaning, that the structure of door 10 is composed of wood. In certain embodiments, door 10 is a “solid wood” door, made from dimensional lumber, rather than multiple sheets of plywood or other sheeting that is pieced together. There is no appreciable amount of metal in any of the components that make up sections 22 ; these wood components, along with any metal hardware, are described below. [0034] A view of the backside, or the interior side, of a prior art door is illustrated in FIG. 3 . This door 100 has an interior surface 114 , first side edge 116 , second side edge 118 , top edge 117 , and bottom edge 119 , and multiple sections 122 A, 122 B, 122 C, 122 D. Sections 122 A, 122 B, 122 C, 122 D are movably held together by hinges 125 . Present on interior surface 114 are reinforcing struts 142 to increase resistance to flexing from side edge 116 to side edge 118 . Each section 122 A, 122 B, 122 C, 122 D can have any number of struts 142 , although generally one or two struts per section are generally used to provide the desired resistance. Struts 142 are generally fastened to the surface of sections 122 A, 122 B, 122 C, 122 D so that struts 142 extend out and away from interior surface 114 . That is, at least a portion of strut 142 , and typically the entire strut 142 , extends into the interior of the garage or other space to which door 100 provides access. [0035] Conversely, a view of the backside, or the interior side, of door 10 according to the present invention is illustrated in FIG. 4 . From this side, interior surface 14 , first side edge 16 , second side edge 18 , top edge 17 , and bottom edge 19 can be readily seen, as can sections 22 A, 22 B, 22 C, 22 D. Sections 22 A, 22 B, 22 C, 22 D are movably held together by hinges 25 . Hinges 25 allow sections 22 A, 22 B, 22 C, 22 D to pivot in relation to one another and allow door 10 to be moveably positioned between open and closed positions, as is typical for overhead garage doors. [0036] Door 10 includes no reinforcing struts extending into the space to which door 10 provides access, that is, door 10 includes no struts that extend above interior surface 14 . In the preferred embodiment, there is no structure, other than hinges 25 and mounting hardware (e.g., roller brackets), that extends out from surface 14 . A handle, to facilitate manual lifting or raising of door 10 , may be present on interior surface 14 . FIG. 5 is a side view of door 10 , reinforcing the lack of reinforcing struts on interior surface 14 . Door 10 of the present invention includes reinforcing struts within the interior of sections 22 , the struts being recessed into or flush with interior surface 14 . The internal construction of door 10 can be understood by reference to FIGS. 6, 6A and 7 . It is noted that FIGS. 6 and 6 A are internal views of door 10 ; that is, interior surface 14 of door 10 is not illustrated, rather, the construction behind interior surface 14 is seen. [0037] Sections 22 of door 10 can be, and preferably are, constructed using a boxed frame assembly, which is a substantially rectangular border surrounding an interior section. Typically, a boxed frame assembly uses a stile and rail construction technique. Referring to FIG. 6A , section 22 B has frame assembly 30 with rails 32 which extend horizontally and stiles 34 which extend vertically. Specifically, frame assembly 30 has a first rail 32 A at the top of section 22 B and a second rail 32 B at the bottom of section 22 B, and a plurality of stiles 34 extending therebetween specifically, a first stile 34 A (at first side edge 16 ), second side stile 34 B (at second side edge 18 ), and an internal stile 34 C. It should be understood that any or all of sections 22 can have this or a similar boxed frame construction. A first layer of material is positioned over frame assembly 30 to form exterior surface 12 and another layer of material is positioned over the other side of frame assembly 30 to form interior surface 14 , as is described further below. Typically, one layer of material is used to on the inside to form interior surface 14 ; one or more layers of material may be used on the outside of frame assembly 30 . [0038] The doors of the present invention include an internal or inset strut in at least one of sections 22 . By use of the term “inset”, what is intended is that no portion of the strut extends above the interior surface 14 of door 10 . By use of the term “internal”, what is intended is that the inset strut is not visible on the interior surface 14 of door 10 , rather, an internal strut is concealed within the interior of door 10 . An internal or concealed strut is a type of inset strut. [0039] FIG. 6 shows an interior of door 10 having an inset strut 40 present in various sections 22 . In particular, section 22 A has inset strut 40 A, section 22 B has inset strut 40 B, and section 22 C has inset strut 40 C. In this embodiment, door 10 does not include an inset strut 40 on section 22 D. FIG. 6A shows section 22 B with inset strut 40 B. Strut 40 is also shown in FIGS. 7, 8 and 11 . [0040] Strut 40 is a reinforcing member for section 22 , providing torsional resistance to section 22 and to door 10 . Strut 40 also stiffens section 22 and reduces sagging, both when in a vertical orientation (e.g., when door 10 is in a closed orientation) and in a horizontal orientation (e.g., when door 10 is in an open orientation). [0041] Referring to the embodiment of FIGS. 6A, 7 and 8 , inset strut 40 is composed of two pieces 40 ′ and 40 ″, each having a first arm 42 and a second arm 44 generally at a right angle to first arm 42 . Pieces 40 ′, 40 ″ can be generally described as L-shaped. The pieces 40 ′, 40 ″ are attached to each other via arms 44 , for example by welding or by structural adhesive. A corner 45 , which is or is close to 90 degrees, is present as a transition between first arm 42 and second arm 44 . The four arms 42 , 44 provide a T-shape for strut 40 . [0042] In alternate embodiments, the inset strut may include only one piece, either 40 ′ or 40 ″, but which does preferably have both arms 42 , 44 ; such a strut would be L-shaped. In yet another embodiment, the inset strut may be formed from a single piece to form a T-shape. Other alternate shapes include U and I shapes, and of course other shapes may be suitable. [0043] Strut 40 has a length between a first end 46 and an opposite second end 48 , with both arms 42 , 44 extending the length of strut 40 . [0044] Typically, first arm 42 is about 0.25 inch to 2 inches long, more typically about 0.5 inch to 1 inch long. Second arm 44 is typically about 0.25 to 3 inches long, more typically about 0.5 to 2 inches long. Arms 42 , 44 typically have a thickness of 20 to 12 gauge, or thicker or thinner, depending on the material, the shape, and the desired strength. [0045] In one particular embodiment, strut 40 is 114 inches long from end 46 to end 48 , arm 42 is 0.75 inch long and arm 44 is 1 inch long. Strut 40 is made from 16 gauge galvanized steel. Holes (spaced 1.5 inches apart) are present in arm 42 to accept a fastener, such as a screw, therethrough, to mount strut 40 to stiles 34 . In this embodiment, three holes and fasteners are used for each stile. In an alternate configurations, more or less holes can be used in an configuration. [0046] Referring to FIG. 6 , for each of sections 22 A, 22 B, 22 C illustrated having strut 40 A, 40 B, 40 C, respectively, the respective strut 40 is centered height wise in section 22 and extends laterally across at least the majority of the width of section 22 , extending short of first side edge 16 and second side edge 18 , for example, about 3 inches. It is understood that strut 40 could extend to side edge 16 and/or side edge 18 . In FIG. 6A , strut 40 B extends from stile 34 A, across stile 34 C, to stile 34 B. Specifically, first end 46 of strut 40 B is present on stile 34 A short of first edge 16 and second end 48 of strut 40 B is present on stile 34 B short of second edge 18 . Preferably, at inset strut extends at least 50% of the width of the section, more preferably at least 75%, and most preferably at least 90% of the width of the section. For example, a 114 inch long strut, on a 120 inch wide section, would be 95% of the width. [0047] The doors of the present invention additionally or alternately include an internal or inset top reinforcing member in the top section, e.g., section 22 D. By use of the term “inset”, what is intended is that no portion of the top reinforcing member extends above the interior surface 14 of door 10 . By use of the term “internal”, what is intended is that the inset top reinforcing member is not visible on the interior surface 14 of door 10 , rather, an internal top reinforcing member is concealed within the interior of door 10 . An internal top reinforcing member is a type of inset top reinforcing member. [0048] FIGS. 9 and 10 illustrate inset top reinforcing member 50 , as does FIG. 11 . Inset top reinforcing member 50 is a reinforcing member for the top of door 10 , providing torsional resistance to the top section 22 D and to door 10 . Inset top reinforcing member 50 also stiffens the top section 22 D and reduces bowing and sagging, both when in a vertical orientation (e.g., when door 10 is in a closed orientation) and in a horizontal orientation (e.g., when door 10 is in an open orientation). [0049] Inset top reinforcing member 50 has a first arm 52 and a second arm 54 generally at a right angle to first arm 52 . A corner 55 , which is or is close to 90 degrees, is present as a transition between first arm 52 and second arm 54 . Top reinforcing member 50 has a length between a first end 56 and an opposite second end 58 . [0050] Typically, first arm 52 is about 0.5 inch to 4 inches long, more typically about 1 inch to 2 inches long. Second arm 54 is typically about 0.5 to 4 inches long, more typically about 1.5 to 3 inches long. Arms 52 , 54 are typically 12 to 18 gauge. [0051] In one particular embodiment, inset top reinforcing member 50 is 120 inches long from end 56 to end 58 , arm 52 is 1.5 inch long and arm 54 is 2 inches long. Inset top reinforcing member 50 is made from 16 gauge galvanized steel. Holes (spaced approximately 20 inches apart) are present in each of arm 52 and arm 54 to accept a fastener, such as a screw, therethrough, to mount inset top reinforcing member 50 to the top rail of a section. Adhesive may additionally or alternatively be used. In an alternate embodiment, some or all of the holes in arms 52 , 54 are approximately 10 inches apart. Preferably, the holes in arm 52 are offset from the holes in arm 54 . Such an inset top reinforcing member 50 is suitable for use with “blended” doors. In the context of this application, “blended” doors have one layer over the exterior surface of frame assembly 30 , with this one layer optionally being a blend of two materials, e.g., tongue-and-groove framed or surrounded by trim boards. [0052] In another particular embodiment, inset top reinforcing member 50 is 120 inches long from end 56 to end 58 , arm 52 is 1.5 inch long and arm 54 is 2.375 inches long. Inset top reinforcing member 50 is made from 16 gauge galvanized steel. Holes (spaced approximately 10 and/or 20 inches apart) are present in each of arm 52 and arm 54 to accept a fastener. Preferably, the holes in arm 52 are offset from the holes in arm 54 . Such an inset top reinforcing member 50 is suitable for use with “layered” doors. In the context of this application, “layered” doors have more than one layer over the exterior surface of frame assembly 30 . For example, one layer e.g., tongue-and-groove, may have another layer, e.g., trim boards, partially covering the first layer. [0053] Referring to FIG. 6 , inset top reinforcing member 50 is present at the top of section 22 D and extends across the width of section 22 D, extending from first side edge 16 to second side edge 18 . It is understood that inset top reinforcing member 50 could extend short of side edges 16 , 18 , however, top reinforcing member 50 should extend at least 50% of the width of section 22 D, more preferably 75%, even more preferably 90%, and most preferably 100% of the width. [0054] FIG. 11 illustrates inset strut 40 mounted in a portion of the door's wood frame assembly, particularly, in center stile 34 C, and inset top reinforcing member 50 mounted in a portion of the door's frame assembly, particularly, in a top rail 32 . Stile 34 C and rail 32 include a recessed portion for receiving strut 40 and reinforcing member 50 , respectively. Mechanical fasteners are shown attaching strut 40 and reinforcing member 50 to the wood frame. Adhesive may additionally be used. [0055] If the surface of stile 34 C and rail 32 were interior surface 12 , inset strut 40 and inset reinforcing member 50 would be flush with interior surface 12 . In this embodiment, however, stile 34 C, rail 32 , strut 40 and reinforcing member 50 would be covered by a material layer that forms interior surface 12 ; thus, strut 40 and reinforcing member 50 are internal strut 40 and internal reinforcing member 50 . [0056] As defined above, an internal or concealed top reinforcing member is defined as one that is not visible on the interior surface 14 of door 10 . Thus, arm 52 is concealed. It should be understood that arm 42 of top reinforcing member 50 may be visible when one looks down onto the top of section 22 D. [0057] For a wood door, frame assembly 30 , which includes rails 32 and stiles 34 , are made from wood, although a wood composite material may also be used. Although screws, bolts, nails and other metal fasteners may be used to hold together frame 30 , frame 30 is considered a wood structure. With a wood structure, a cope and stick technique is preferably used to join frame 30 together. [0058] Generally any wood material is suitable for rails 32 and stiles 34 , although a preferred material is Douglas Fir, Southern Yellow Pine, or other wood having similar or greater strength and density. A suitable size for rails 32 and stiles 34 is common 2×4 or 2×6 dimensioned lumber, although other sizes can be used. [0059] Frame assembly 30 is preferably constructed using a pocket hole attachment system, which is a well-known attachment construction known in the wood construction arts. A bore is provided angled through the first piece of wood (e.g., stile 34 ) into the second piece of wood (e.g., rail 32 ). The bore is sized and shaped so that the head of a fastener, such as a wood screw, is seated within the first piece, and the fastener extends into the second piece. Preferred fasteners for this application include 2 inch hardened steel screws. An adhesive may be included in the joint between rails 32 and stiles 34 . [0060] Preferably, present over frame assembly 30 and, inset struts 40 , is at least one layer of material, preferably wood, which forms interior surface 14 . Additionally, at least one layer of material, preferably wood, is present over frame assembly to form exterior side or surface 12 . Often, multiple layers are used to form a decorative surface for surface 12 . [0061] Examples of suitable wood layers for surfaces 12 , 14 include solid wood boards, plywood, OSB, chip board, and the like. Suitable thickness for these layers include 3/16 inch, ¼ inch, ⅜ inch, ½ inch, and ⅝ inch. [0062] As mentioned above, exterior surface 12 preferably includes a decorative façade. This façade may be formed from any combination of layers, such as tongue and groove combined with dimensional boards. Examples of suitable woods for decorative layers include No. 3 Western Cedar, Oak, Cherry, Mahogany, Poplar, Yellow Pine, Redwood, spruce, Fir, Maple, Douglas Fir, Birch, Teak, Hickory, Cyprus, and No. 2 Aspen, Western Pine, Eastern Pine and Ponderosa Pine, and other such wood materials. Suitable thicknesses for decorative layers include any thickness from ⅛ inch to 1 inch. In one particular construction, a decorative layer is ¾ inch thick red cedar plywood and ¾ inch thick cedar face boards are used as decorative trim boards. In another particular construction, a decorative layer is 9/16 inch thick v-groove facing. When trim boards are placed on top of the decorative layer, e.g., cedar plywood or v-groove facing, the resulting section or door is referred to as a “layered” section or door. When trim boards are placed adjacent to (i.e., not on top of) the decorative layer, the resulting section or door is referred to as a “blended” section or door. [0063] The decorative layers, such as decorative plywood and/or decorative trim boards, can be attached to frame 30 and any other exterior layer by any suitable fastening system, including mechanical fasteners (e.g., nails, screws, staples, etc.), chemical attachment (e.g., adhesives), or any combination. [0064] An insulation material may be positioned in an interior area of section 22 , within frame 30 between rails 32 and stiles 34 . As example of a suitable insulation material is 1⅜ inch thick polystyrene insulation, either expanded or extruded. [0065] Inset struts 40 and inset top reinforcing member 50 can be made from any suitable material such as metal, plastic, composites, or even wood or wood composites, but it is preferred that metal (e.g., galvanized steel, stainless steel, steel, iron, or aluminum) forms struts 40 and member 50 . Struts 40 and member 50 can be attached to section 22 by any suitable fastening system, either mechanical or chemical, or a combination. Mechanical attachment systems include screws, nails, bolts, staples, and the like. Chemical attachment systems use adhesive or glue. If an adhesive or glue is used, any metal pieces should be cleaned with a cleaner to remove any oily residues from the surface in order to promote better adhesion. Any or all of struts 40 , top reinforcing member 50 , and mechanical fasteners used to attach struts 40 and/or member 50 can be treated or coated, such as powder coated. [0066] The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention. For example, doors according to the present invention may include a combination of inset strut(s) and conventional strut(s). Or, doors according to the present invention may include conventional strut(s) with an inset top reinforcing member, or, inset strut(s) with a conventional top reinforcing member. Those skilled in the art will readily recognize additional modifications and changes that may be made to the present invention without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention, which is set forth in the following claims.	A sectional wood overhead door used to create access to building interiors in residential and commercial applications. The door includes an inset lateral reinforcing strut, U-bar, brace, or other reinforcing member, with the strut being inset at least partially into the door. No portion of the strut extends out from or above a surface of the door. When the door is installed for use, the inset struts do not extend past the interior surface of the door. In some designs, the inset struts are concealed and are not visible or otherwise discernable by one looking at or otherwise examining the internal surface of the door.	4
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 11/254,770, filed Oct. 21, 2005, now U.S. Pat. No. 7,828,251, which claims the benefit of U.S. Provisional Application No. 60/620,688, filed Oct. 22, 2004. Each patent application identified above is incorporated here by reference in its entirety to provide continuity of disclosure TECHNICAL FIELD [0002] This invention relates generally to an alignment and support apparatus for aligning and supporting conduit and the like during a construction operation. More specifically, this invention relates to an interlocking and latching alignment and support apparatus that keeps conduit and the like supported and aligned during a concrete pour operation. BACKGROUND [0003] Many building structures, such as foundations, floors, ceilings, walls, and the like, include a concrete slab having conduit, pipes and the like embedded therein. Form boards are typically used to provide the desired shape of concrete slab. Concrete is poured into the form, and once set, the form is removed to reveal a concrete slab with conduit, pipes and the like embedded therein. It is very important that the conduits and/or pipes do not move during the concrete pouring operation so that the conduit or pipes remain in a known location according to the building plans. [0004] For this reason, various apparatus and methods are employed in the construction art to support a desired configuration of pipes until the concrete (e.g. for a foundation) is poured and has had sufficient time to set or harden, thereby saving space by embedding the pipe work and the like in the concrete. Traditionally, for example, the outside bases of conduit spacers are fixed to the ground with, for example, rebar, with the remaining pieces of conduit not being attached. This allows the sections attached to the base section to move during concrete pouring which disassembles the horizontal connections. [0005] For example, lengths of rebar are driven into the ground and sections of pipe are taped to the rebar to provide structural support to the conduit configuration. Because the rebar and tape are typically removed prior to the pouring of concrete so that footers may be dug, the conduits or pipes will often sag prior to the concrete pour operation, and unless repositioned will result in a plumbing or wiring configuration that is permanently crooked when later embedded in cured concrete. [0006] Sagging or displacement often results in a poor pipe work configuration that causes pipe leaks, water pressure problems, and drainage issues all of which are best avoided by maintaining proper support and alignment of pipe work and the like both prior to and during a concrete pour operation. Sagging or displacement during pour often results in a poor or undesirable electrical conduit configuration, with conduit located incorrectly relative to building specifications. Other problems may result from displaced, incorrectly located, or sagging conduits and pipes. SUMMARY [0007] Thus, an exemplary aspect of this invention includes interlocks with latches that allow the assembly to act as one rigid body preventing the bank of components from moving and/or collapsing upon itself. Through the use of an easily latched and unlatched interlock mechanism, the spacers can be assembled and/or disassembled to provide a sturdy, rigid structure. [0008] An exemplary aspect of the invention relates to a latch concept for conduit spacers. In particular, an exemplary embodiment of the invention relates to an integral latch that restricts the conduit spacers from moving vertically with respect to each other. If the conduit spacers do not include a vertically restraining latch, the conduit spacers could float during, for example, pouring of concrete. [0009] The components illustrated herein can be scaled to any size as well as made from any material or combination of materials including, but not limited to, plastics, composites, metals, and alloys. BRIEF DESCRIPTION OF DRAWINGS [0010] FIG. 1 is a front elevation view of an exemplary embodiment of a base spacer in accordance with the present invention; [0011] FIG. 2 is a side elevation view of a receiving interlock side of the base spacer of FIG. 1 ; [0012] FIG. 3 is a side elevation view of a positive interlock side of the base spacer of FIG. 1 ; [0013] FIG. 4 is a front elevation view showing two exemplary base spacers that have been interlocked side-by-side with each other; [0014] FIG. 5 is a top view of the base spacer of FIG. 1 ; [0015] FIG. 6 is an expanded partial view of the side interlock joint shown in FIG. 4 showing an exemplary interlock latching mechanism in detail; [0016] FIG. 7 is a bottom view of the base spacer of FIG. 1 ; [0017] FIG. 8 is a front elevation view of an exemplary embodiment of an intermediate spacer in accordance with the present invention; [0018] FIG. 9 is a side elevation view of a positive interlock side of the intermediate spacer of FIG. 8 ; [0019] FIG. 10 is a side elevation view of a receiving interlock side of the intermediate spacer of FIG. 8 ; [0020] FIG. 11 is a front elevation view showing two base spacers interlocked in an opposing arrangement; and [0021] FIG. 12 is a front elevation view showing two base spacers interlocked on opposite ends of an intermediate spacer. [0022] Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION [0023] The terms “conduit” and “pipe” are used interchangeably in this specification. Further, it should be appreciated that the present invention may be used to support and align other elongate articles beyond conduits, pipes and the like. The terms “device”, “apparatus”, and “spacer” are used interchangeable herein. [0024] The terms “top”, “bottom”, and “sides” are used in the specification to describe the various views of the figures. It should be appreciated that in actual use, an embodiment of the invention may be rotated either horizontally or vertically in order to assemble a support and alignment structure. And, as a result of such rotation, the descriptive terms may not literally apply to a particular construction. In other words, the various terms of “top”, “bottom”, “base” and the like are relative and are used here to describe the figures for illustration purposes and are not intended to limit the embodiments shown to any particular orientation. [0025] Referring to FIG. 1 , the exemplary base spacer 10 comprises a body 12 having a middle portion 14 , a positive interlock side 16 , a receiving interlock side 18 , a bottom 20 and a top 22 . The base spacer body 12 also has a front 24 and a back 26 (shown in FIGS. 2 and 3 ). [0026] The middle portion 14 of the base spacer body 12 is disposed between the two sides ( 16 and 18 ) and the top 22 and bottom 20 . The middle portion 14 may be formed as a solid member or as a member that is partially open. The middle portion 14 may optionally be formed with one or more stiffening ribs 28 that may increase the load bearing capacity of the base spacer 10 and may serve to reduce twisting or flexing by the base spacer 10 . [0027] Referring to FIGS. 1 and 3 , the exemplary positive interlock side 16 includes a positive side projection 30 extending outwardly from the side of the base spacer body 12 . The positive side projection 30 is adapted to slidably engage the receiving interlock side 18 of another base spacer. The positive side projection 30 is widest at the outermost side and tapers inwardly to become narrower nearest the base spacer body (this tapering can be best seen in FIG. 5 , which is a lop view of the base spacer of FIG. 1 ). The positive side projection 30 is nearly the same height as the side of the base spacer. In an alternative exemplary embodiment, the positive side projection 30 comprises a plurality of vertically spaced segments, instead of a continuous single piece. The base spacer includes a latch member 32 disposed near the bottom of the positive interlock side 16 and extending outwardly at a substantially ninety degree angle from the positive interlock side 16 . The latch member 32 may be integral with the positive side projection, or may be a separate member not integral with the positive side projection. Other latch member angles could be used. [0028] The middle portion 12 of the base spacer body is recessed slightly from the side and from the bottom of the positive side projection 30 , and extending toward the top of the spacer to approximately one-quarter of the way up from the bottom of the positive side projection 30 . This recess provides a gap 34 between the positive side projection 30 and the middle portion 14 of the base spacer body 12 . The positive side projection 30 is also narrower over the gap 34 than at the rest of the projection, as can be seen in the positive side elevation view of FIG. 3 at the portion of the positive side projection 30 indicated by reference number 36 . [0029] Referring to FIG. 1 , the gap 34 between the positive side projection 30 and the middle portion 14 of the base spacer 10 permits the positive side projection 30 to flex inwardly as the positive side projection 30 engages the receiving side 18 of another spacer. This inward flex accommodates the latch member 32 which extends outwardly. Once the base spacer 10 is fully interlocked side-by-side with another spacer, the latch member 32 , under tension from being inwardly flexed, will extend outwardly into a recess 38 on the receiving side of the other spacer and form a latching mechanism between the two spacers. Two base spacers that have been interlocked side-by-side are shown in FIG. 4 , described below. [0030] Referring to FIGS. 1 and 2 , the exemplary receiving side 18 of the base spacer includes a plurality of projections 40 for receiving and engaging the positive interlock side projection 30 of another base spacer. Together with the positive side projection 30 , the plurality of receiving side projections 40 form a partially open dovetail-like interlocking joint when assembled. The plurality of receiving side projections 40 are disposed and distributed along the receiving side 18 from top to bottom. A number of the projections are disposed toward the front of the base spacer ( 42 in FIG. 2 ) and a number of the projections are disposed toward the rear of the base spacer ( 44 in FIG. 2 ). It should be appreciated that while a specific number of projections are illustrated, any number of projection(s) can be used. [0031] Referring to FIG. 2 , the front and rear projections ( 42 and 44 ) oppose each other to form a channel in which the positive side projection of another spacer ( 46 , dashed line) can slide into engage. The front and rear receiving side projections ( 42 and 44 ) taper from narrow at the outside to wider on the inside near the base spacer body. This tapering gives the receiving side channel an opposite shape from the positive side projection and allows the positive side projection to engage and interlock with the receiving side of another base spacer. FIG. 2 shows the arrangement of receiving side projections on the base spacer of FIG. 1 . A positive side projection is shown in FIG. 2 by a dashed line and indicates where a positive side projection would be located when fully interlocked and in place. [0032] Two base spacers are engaged in a top to bottom, or opposed interlocking manner when the positive side projection is slid in place and is fully interlocked when the latch 32 of the positive side projection 30 reaches the bottom of the receiving side 18 and engages the recess 38 provided thereon. Again, a fully interlocked and latched arrangement of two base spacers is shown in FIG. 4 . The latching mechanism is shown in greater detail in FIG. 6 . [0033] Referring to FIG. 1 , the top 22 of the base spacer 10 includes a conduit recess 48 for receiving a conduit, pipe or in general any elongate article and/or the recessed portion may be left empty. For example, the conduit recess 48 may be formed as a concave semicircle such that a conduit may be placed on top of the base spacer and will rest in the recess. The conduit recess 48 may be formed having a different size or radius depending on the contemplated use of the invention and the size of the conduit or pipe to be aligned and supported. Further, the conduit recess 48 may be formed having a shape to conform to a cross-sectional shape of a conduit, pipe or other elongate article that has a cross-sectional shape other than semicircular. In an exemplary embodiment not shown, a plurality of recesses could be formed permitting a single spacer to support multiple conduits. [0034] Still referring to FIG. 1 , the top 22 of the exemplary base spacer 10 includes two vertical interlock members each disposed on the top of the base spacer near a side. A positive vertical interlock member 50 is disposed on the top near the positive interlock side 16 and extends in an upward vertical direction from the base spacer body 12 , the positive vertical interlock member 50 for inserting and interlocking with a receiving vertical interlock member 52 of another base spacer. The positive vertical interlock member 50 includes a series of angled protrusions 54 on each side. [0035] A receiving vertical interlock member 52 is disposed on the top near the receiving interlock side 18 and includes a recess 56 extending in a downward vertical direction into the base spacer body 12 , the recess 56 for receiving a positive vertical interlock member 50 of another base spacer. The recess 56 is lined on each side with a series of angled protrusions 58 , followed a section 60 having no angled protrusions. The receiving vertical interlock member includes a tab 61 extending away from the recess 56 . [0036] When two base spacers are interlocked in a vertically opposed manner, with one base spacer on the bottom and one base spacer on the top (as shown in FIG. 11 ), the two spacers are oriented such that the positive vertical interlock member 50 of the bottom base spacer is aligned with the receiving vertical interlock member 52 of the top base spacer. And, the receiving vertical interlock member 52 of the bottom base spacer is aligned with the positive vertical interlock member 50 of the top base spacer. [0037] As mentioned above, both the receiving and the positive vertical interlock members ( 52 and 50 ) include a series of angled protrusions ( 58 and 54 ) extending from both side surfaces of both interlock members. These angled protrusions ( 58 and 54 ) create an interlocking and latching mechanism when a positive vertical interlock member 50 is inserted into a receiving vertical interlock member 52 . As a positive vertical interlock member 50 is inserted into a receiving vertical interlock member 52 , each angled protrusion engages and interlocks with a next angled protrusion, until, when fully assembled, each angled protrusion has engaged and interlocked with an angled protrusion on an opposing vertical interlock member, as shown in FIG. 11 . The vertical interlocks are easily releasable by inserting a screwdriver, or other suitably thin instrument into the recess 56 and opening the receiving vertical interlock enough so that the angled protrusions on the positive vertical interlock member and the receiving vertical interlock member disengage, thus permitting the vertical interlock members to be released from each other. [0038] Referring to FIGS. 2 and 3 , the bottom of the exemplary base spacer body includes a support member 62 that extends from the front 24 and back 26 of the base spacer body 12 in a plane perpendicular to the front 24 and back 26 of the base spacer body 12 . The support member 62 forms a stabilizing platform such that the base spacer 10 may be placed on a flat, level surface and stand upright without being supported by any other apparatus. The support member 62 optionally includes one or more reinforcing ribs 64 disposed on each side and joining the support member 62 and the base spacer body 12 . The reinforcing ribs 64 are adapted to strengthen and stabilize the support member 62 relative to the base space body 12 . The support member 62 may optionally include holes (shown in FIG. 7 ) extending from a top surface of the support member to a bottom surface of the support member. The holes may be adapted and constructed to allow a fastener to be inserted through the support member 62 and into an underlying surface, such that the base spacer 10 may be secured in place during a construction operation. Even without holes in the support member 62 , a piercing fastener, such as a nail may be used to affix the support member 62 to an underlying surface. The support member 62 may be narrower in a middle portion and wider at the sides, as shown in FIG. 7 . When a plurality of base spacers, each having holes in their respective support members, is interlocked it may be advantageous to use fasteners in only some of the holes to attach the base spacers to an underlying surface. Because the base spacers are interlocked and latched, the base spacers which do not have fasteners will still remain in place. [0039] FIG. 4 is a front elevation view showing two exemplary base spacers that have been interlocked side-by-side with each other. Specifically, a first base spacer 400 is interlocked in a side-by-side manner with a second base spacer 402 . Two base spacers are interlocked by sliding the sides together to engage the positive side projection of one base spacer with a receiving side projection of another base spacer. The latching mechanism 404 is shown in greater detail in FIG. 6 and described below. The latching mechanism is easily releasable by inserting a screwdriver, or other thin instrument, between the positive side projection 30 and the receiving interlock side 18 , at a point near the latch member 32 and moving the latch member toward the recess 34 to disengage the latch member 32 from the recess 38 . [0040] FIG. 5 is a top view of the exemplary base spacer of FIG. 1 . In particular, an exemplary support member 62 extends from the front 24 and back 26 of the base spacer body 12 in a plane perpendicular to the front 24 and back 26 of the base spacer body 12 . [0041] FIG. 6 is an expanded partial view of the side interlock joint shown in FIG. 4 showing an exemplary interlock latching mechanism in detail. It can be better seen in FIG. 6 how the latch member 32 of the positive side projection 30 engages the recess 38 on the receiving side 18 . The positive side projection 30 slidably engages the receiving side projections 40 to create a partially open dovetail-like joint. [0042] FIG. 7 is a bottom view of the exemplary base spacer of FIG. 1 . In particular, an exemplary embodiment of a support member 62 includes holes 702 for inserting fasteners through the support member 62 and into an underlying surface. The support member 62 also includes a middle portion 704 that is narrower than the two end portions. [0043] FIG. 8 is a front elevation view of an exemplary embodiment of an intermediate spacer in accordance with the present invention. In particular, an intermediate spacer 80 comprises a body 82 having a middle portion 84 , a positive interlock side 86 , a receiving interlock side 88 , a bottom 90 and a top 92 . The intermediate spacer body 82 also has a front 94 and a back 96 (shown in FIGS. 9 and 10 ). [0044] The middle portion 84 of the intermediate spacer body 82 is disposed between the two sides ( 86 and 88 ) and the top 92 and bottom 90 . The middle portion 84 may be formed as a solid member or as a member that is partially open. The middle portion 84 may optionally be formed with one or more stiffening ribs 98 that may increase the load bearing capacity of the intermediate spacer 80 and may serve to reduce twisting or flexing by the intermediate spacer 80 . [0045] Referring to FIGS. 8 and 9 , the exemplary positive interlock side 86 includes a positive side projection 100 extending outwardly from the side of the intermediate spacer body 82 . The positive side projection 100 is adapted to slidably engage the receiving interlock side 98 of another intermediate spacer. The positive side projection 100 is widest at the outermost side and tapers inwardly to become narrower nearest the base spacer body (this tapering is similar to that shown for the positive side projection 30 in FIG. 5 , which is a top view of the base spacer of FIG. 1 ). The positive side projection 100 is nearly the same height as the side of the intermediate spacer and is optionally tapered at each end. [0046] Referring to FIGS. 8 and 10 , the exemplary receiving side 88 of the intermediate spacer includes a plurality of projections 110 for receiving and engaging the positive interlock side projection 1000 of another intermediate spacer. Together with the positive side projection 100 , the plurality of receiving side projections 110 form a partially open dovetail-like interlocking joint when assembled. The plurality of receiving side projections 110 are disposed and distributed along the receiving side 88 from top to bottom. A number of the projections are disposed toward the front of the base spacer ( 112 in FIG. 10 ) and a number of the projections are disposed toward the rear of the base spacer ( 114 in FIG. 10 ). It should be appreciated that while a specific number of projections are illustrated, any number of projection(s) can be used. [0047] Referring to FIG. 10 , the front and rear projections ( 112 and 114 ) oppose each other to form a channel in which the positive side projection 100 of another spacer can slide in to engage the receiving side 88 . The front and rear receiving side projections ( 112 and 114 ) taper from narrow at the outside to wider on the inside near the intermediate spacer body. This tapering gives the receiving side channel an opposite shape from the positive side projection and allows the positive side projection to engage and interlock with the receiving side of another intermediate spacer. FIG. 10 shows the arrangement of receiving side projections on the intermediate spacer of FIG. 8 . [0048] Referring to FIG. 8 , the top 92 and bottom 90 of the intermediate spacer 80 includes conduit recesses 118 , each having a radius R, for receiving a conduit, pipe or in general any elongate article and/or the recessed portions may be left empty. For example, the conduit recesses 118 may be formed as a concave semicircle such that a conduit may be placed on top and bottom of the intermediate spacer and will rest in the recesses. The conduit recesses 118 may be formed having a different size or radius depending on the contemplated use of the invention and the size of the conduit or pipe to be aligned and supported. Further, the conduit recesses 118 may be found having a shape to conform to a cross-sectional shape of a conduit, pipe or other elongate article that has a cross-sectional shape other than semicircular. In an exemplary embodiment not shown, a plurality of recesses could be formed permitting a single spacer to support multiple conduits. [0049] Still referring to FIG. 8 , the top 92 and bottom 90 of the exemplary intermediate spacer 80 includes two vertical interlock members disposed on each of the top and bottom of the intermediate spacer near a side. A positive vertical interlock member 120 is disposed on the top near the positive interlock side 86 and extends in an upward vertical direction from the intermediate spacer body 82 . Another positive vertical interlock member 120 is disposed on the bottom near the receiving interlock side 88 and extends in an downward vertical direction from the intermediate spacer body 82 . The positive vertical interlock members 120 for inserting and interlocking with receiving vertical interlock members 122 of other spacers. The positive vertical interlock member 120 includes a series of angled protrusions 124 on each side. [0050] A receiving vertical interlock member 122 is disposed on the top near the receiving interlock side 88 and includes a recess 126 extending in a downward vertical direction into the intermediate spacer body 82 , the recess 126 for receiving a positive vertical interlock member 120 of another spacer. Another receiving vertical interlock member 122 is disposed on the bottom near the positive interlock side 86 and includes a recess 126 extending in a upward vertical direction into the intermediate spacer body 82 , the recess 126 for receiving a positive vertical interlock member 120 of another spacer. The recesses 126 are lined on each side with a series of angled protrusions 128 , followed a section 130 having no angled protrusions. The receiving vertical interlock member 122 also includes a tab 131 extending away from the recess 126 . [0051] When two intermediate spacers are interlocked in a vertically opposed manner with another intermediate spacer or a base spacer, for example, with one base spacer on the bottom and one base spacer on the top (as shown in FIG. 12 ), the two spacers are oriented such that the positive vertical interlock member 120 of one intermediate spacer is aligned with the receiving vertical interlock member 122 of another intermediate spacer (or the receiving vertical interlock member 52 of a base spacer). And, the receiving vertical interlock member 122 of one intermediate spacer is aligned with the positive vertical interlock member 120 of another intermediate spacer (or the positive vertical interlock member 50 of a base spacer). [0052] As mentioned above, both the receiving and the positive vertical interlock members ( 122 and 120 ) include a series of angled protrusions ( 128 and 124 ) extending from both side surfaces of both interlock members. These angled protrusions ( 128 and 124 ) create an interlocking and latching mechanism when a positive vertical interlock member 120 is inserted into a receiving vertical interlock member 122 . As a positive vertical interlock member 120 is inserted into a receiving vertical interlock member 122 , each angled protrusion engages and interlocks with a next angled protrusion, until, when fully assembled, each angled protrusion has engaged and interlocked with an angled protrusion on an opposing vertical interlock member, as shown in FIG. 12 . The vertical interlocks are easily releasable by inserting a screwdriver, or other suitably thin instrument into the recess 126 and opening the receiving vertical interlock enough so that the angled protrusions on the positive vertical interlock member and the receiving vertical interlock member disengage, thus permitting the vertical interlock members to be released from each other. [0053] FIG. 11 is a front elevation view showing two base spacers interlocked in an opposing arrangement. In particular, a first base spacer 140 is interlocked in a vertically opposed arrangement with another base spacer 142 . The description of the vertical interlocks may be found above in the description of FIG. 1 . A circular conduit support and alignment opening 144 is created by the interlocked base spacers. [0054] FIG. 12 is a front elevation view showing two base spacers interlocked on opposite ends of an intermediate spacer. In particular, a first base spacer 150 is vertically interlocked with an intermediate spacer 152 , which is in turn vertically interlocked with another base spacer 154 . This configuration of an intermediate spacer and two base spacers creates a first conduit opening 156 and a second conduit opening 158 . [0055] It should be appreciated that base spacers and intermediate spacers of the present invention may be arranged in various configurations according to a contemplated uses of the invention. [0056] Base spacers and/or intermediate spacers of the present invention can be made of any suitable material such as a plastic, metal, alone or in combination, or formed of a composite material. For example, the spacers shown in FIGS. 1 and 8 can be made of molded plastic in one piece by an injection molding process. Alternatively, the spacers may be individually made of a metal such as lightweight aluminum, copper or steel, or made of, for example, ABS plastic (ABS, acrylonitrile-butadiene-styrene) or PVC (polyvinylchloride), or other plastic. If made of metal, the spacers may be formed by pressing, stamping, casting, or other technique suitable to form spacers in accordance with the present invention. If made of metal, the spacers may be covered in a suitable coating to prevent unwanted interactions between the spacers and metal pipes or conduits made of a dissimilar metal. Alternatively, the spacers may be made principally of a metal but with some parts made of plastic. Suitable plastics include (but are not limited to): reinforced molded plastic, PVC and ABS, for example. [0057] As is apparent from the above description and the figures referenced therein, there is provided an interconnecting alignment and support system with latching mechanism in accordance with the present invention. While this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be, or are, apparent to those of ordinary skill in the applicable arts. Accordingly, applicant intends to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this invention.	An interconnecting alignment and support system for supporting and maintaining alignment of at least one conduit or pipe is disclosed. The system may be used, for example, during a concrete pour operation or other construction operation. The system comprises a base spacer and, optionally, one or more of an intermediate spacer and/or another base spacer. The base spacer is constructed to be capable of interlocking with another spacer on each side and the top. The intermediate spacer is constructed to be capable of interlocking with another spacer on each side and both the top and bottom. The interlocks on the spacers may be releasably latched when fully interlocked. By interlocking the spacers, a matrix structure for aligning and supporting conduit or pipe may be created. The base spacer is attachable to a surface, so that the alignment and support system may be fixed in place.	4
CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation of application Ser. No. 08/080,296 filed Jun. 21, 1993, now abandoned. FIELD OF THE INVENTION The present invention is in the area of instruments and systems for managing and mixing audio input for production purposes, such as recordings, and pertains particularly to input actuators and means for resetting same. BACKGROUND OF THE INVENTION Audio production for television, video, film, and recorded music sales is a large and growing enterprise, and is the foundation of much of the entertainment industry. Automation in the form of computerization is becoming more and more important as the basis of technical advances in this industry, to provide ability to mix and process more sophisticated and more voluminous audio input, and to provide more flexibility in output. Computerization is also seen as a requirement for cost-effective competition. Manual instruments, systems, and techniques are, by comparison, increasingly more expensive to use. The basic instrument of audio production is the production mixing console, a workstation presenting an interface to a sound engineer through which he or she may condition multiple channels of audio input, and mix the conditioned results into mono or stereo outputs for direct broadcast or for recording. A production mixing console, hereinafter a mixer, typically presents arrays of input devices, such as switches, knobs, and "faders", for an engineer to set to condition and route audio signals. A fader is typically a slide rheostat through which an amplitude may be adjusted as a result of the linear position of the input lever relative to a track. Mixers typically route audio input signals to individual channels, and each such channel has a repetitive layout of switches, knobs, and faders. For example, a single channel can have more than one input, such as a microphone input and an input from an instrument, a group of instruments, or a tape. Using the controls on a mixer an engineer can select microphone, line, and tape inputs, route the inputs to signal conditioning devices like faders and equalizers, and mix and route the output from the conditioning devices as well. There is typically a selective ability to monitor audio signals, such as by headphones, and often a microphone for talkback by the sound engineer operating the console. Audio mixing, especially with digital techniques and computer control, is historically a rather recent development. When rock-and-roll music was first introduced there was no such device as a mixer. In the fifties, recording was done by direct input. Modern mixing was initiated about the time of the appearance of the Beatles, and the first units were highly individualistic. Through the sixties and early seventies direct audio mixers continued to be developed, and continued to be relatively small units with a few channels and were very unique in layout. In the mid-seventies standards began to appear, especially relative to layout of switches, rotary potentiometers, and faders. With a standard layout it became possible for a sound engineer to go from one studio to another, and take over the functions comfortably. In the early development and well into the late seventies, mixers were completely manual. The audio signals were routed to the mixer, and directly through the switches, pots, and faders. As a result, there were some definite limitations and problems. For example, with the audio signals routed directly through the switching and signal processing devices, it was necessary that heavy duty, low noise devices be developed. Without ultra-high quality devices, contacts, rheostat slides, and the like produce unwanted clicks and other noises that are incorporated into the audio signals. In answer to some of the problems of direct-audio mixing consoles, some manufacturers have developed digital systems, wherein the input devices on the console do not directly control audio processing equipment, but instead provide digital input, which may be manipulated and saved by the system, and used indirectly to control other devices that process audio signals. FIG. 1 is an isometric view of a system 11 developed by Euphonix, Inc. of Palo Alto, Calif. for applying the power of digital techniques to audio processing and mixing. In this system console 13 is almost entirely digital, and all audio processing is accomplished in an audio tower 15. FIG. 2 is an illustration of a pattern 17 of input devices, such as knobs, slide rheostats, and so forth, on the front panel of the console of FIG. 1. The purpose of FIG. 2 is to illustrate the density of input devices and position indicators, which pretty much cover the console surface, being arranged in channels and blocks of like devices. These input devices provide digital position signals which are manipulated and stored, and used to compose and send digital signals to digitally controllable audio processing and mixing devices in the audio tower. The move to digital systems has provided a very important feature for audio engineers, that was simply not before available. When an engineer has a console set for a particular purpose, say a particular musical group doing a particular sort of music, he or she invariably encounters the situation where a previous complete setting is desired. Before the advent of digital systems, the only answer was to make notes, mental and otherwise, of settings, and then reset all of the input devices on the board from memory and the notes. With the advent of digital systems, a computer associated with the system can remember the setting of every knob, slide switch, and pushbutton. It is only necessary to provide a signal to store all current settings (often called a "snapshot" in the art). Then, at a later time, another signal can retrieve the previous settings from memory storage. The way the computerized system "gives back" the information, though, presents new problems in the art. One difficulty is related to the nature of the digital input devices, particularly knobs. In conventional, directly-coupled systems, knobs operate rotary potentiometers. An example is a one-turn pot. The pot had a minimum and a maximum input setting, and could be set at any position in between, the resistance of the pot being proportional to the setting position setting. In a digital system a knob is typically sensed by a shaft encoder, and the "real" setting is determined by recording the amount of rotary movement from an assigned base, or zero, position. Such a rotary input can correctly be called an infinite knob, in that there is no minimum or maximum physical setting. A new base position may be assigned at any time. Likewise, a new position relative to "zero" may be assigned at any time. FIG. 3 is a block diagram illustrating the general situation with a series of digital input knobs 19, 21, and 23, representing a set of knobs 1-n. Shaft encoders 25, 27, and 29 respectively "read" the rotation of knobs 19, 21, and 23, and present the magnitude and direction of rotary movement to a CPU 31, configured to calculate and store values in a series of operating registers 33 in RAM 39. The values in operating registers 33 are used by the digital system to drive signal processors that actually alter and mix the audio signals input to the system. It will be apparent to one with skill in the art, as well, that there may be multiple processors, various kinds of bus devices such as bus 30, and other arrangements of digital elements for computation and communication, which are known in the art. The encoders read discrete increments of rotary motion in some number of increments of revolution, the greater the number the greater the resolution. For example, a particular encoder may be configured to report 256 increments per revolution. The setting for each knob is determined in operating registers 33 by adding and subtracting the discrete increments of rotation. A setting (snapshot) of the series of knobs 1-n is made on signal by the engineer operating the board by storing the immediate value of operating registers 33 in another series of registers 35 for later retrieval and use, and then continuing to update the immediate registers. Any number of snapshots may be made and stored, depending on the configuration of the system, in separate memory register locations, with the snapshots having names or numbers for identification in retrieval. In the digital system, when one wishes to retrieve a snapshot, to set up the board according to a previously stored global setting, a signal is given with the name or number of the snapshot to be restored, and the stored setting (such as the values in registers 35) is retrieved and substituted for the values in operating registers 33. Once an engineer recalls a setting, and all of the operating registers are reset to the recalled value, representing knob positions, the idea is to proceed from that point making new adjustments in the settings to account for changing situations and conditions, but now a serious problem emerges. The problem is, that in the older, directly-coupled system, there were absolute minimum and maximum positions. A knob, then, could be imprinted with an indicator line or arrow to align with an indicator on the panel, to tell an engineer at a glance the absolute setting. The knobs in the digital case are not directly coupled, however, and the recalling of a setting provides the desired operating values in the operating registers, but does nothing to indicate a relative knob position. The knobs are not reset, so the engineer is deprived of critical feedback. There are several ways this problem might be solved. One solution known to the inventors is to have absolute indicators on the knobs and the panel, and to provide motor drives for the knobs, so when a snapshot is recalled, the recalled values are used to operate the motors to drive the knobs to the recalled setting. Then the engineer can operate the board from the new position just as is done in the older, directly-coupled systems. Considering the density of operating devices as shown in FIG. 2, one can easily understand the difficulty of the motor-drive solution. The motor drives are relatively bulky, the drives are expensive, having to be coupled in a manner, such as by clutches, to allow manual movement of the knobs after resetting, and the density of control and power wiring behind the panel is typically more than doubled. Heat generation is increased, and system reliability is adversely affected. Another possible solution is shown in FIG. 4A. In this case, knob 37 has a series of built-in LEDs, such as LED 40, around the periphery, and an absolute indicator 41 on the panel. When a snapshot is recalled, the new setting value is used to light the one appropriate LED in the knob that most closely shows the new setting relative to absolute indicator 41. If the recalled value for this particular knob indicates 50% of full value, for example, the system will light LED 43, 180 degrees from the absolute indicator. The knob is then effectively "reset" just as though driven to a new position by a motor. The engineer knows which direction of rotation increases setting value, so that is not a problem. The LEDs in the knob solution suffers from the density problem as well. The panel density dictates that knobs are relatively small, and there is a low limit to the number of LEDs that may be installed in one knob, providing poor resolution. Also, there is the problem of selectively lighting the LEDs in the rotary knob. FIG. 4B shows a variation of the solution of FIG. 4A. In this case, knob 45 has an absolute indicator 47, and the LEDs are arranged in a circle around the knob, such as LED 49. When a setting is recalled, the appropriate LED is lighted indicating the setting. For example, if the recalled setting is 50% of full value, LED 51 may be lighted. The solution of FIG. 4B relieves the resolution problem of that of FIG. 4A, but not by much. In addition, there must be some reliable means of keeping track of the absolute position of knob 45, and the recalled settings force the engineer to operate from a new absolute position after each recall. What is needed is a means of providing the new setting positions to the engineer quickly and reliably without sacrificing resolution or increasing wiring density and complexity. SUMMARY OF THE INVENTION In a preferred embodiment a system for digital input and virtual feedback is provided comprising manually operable input means for providing a digital signal relative to movement of the input means, display means for displaying a virtual image of the manually operable input means including position indication, CPU means for managing operation of the system, and for receiving, processing, and routing digital signals from the input means and driving the display means, and memory means for storing data and control routines for use by said CPU means. The CPU means is configured to drive the display means to provide visual position indication on the virtual image corresponding to movement of the input means, and to provide the digital signals to digitally controllable devices. The invention is particularly applicable to a digital audio mixer panel, and in that aspect allows resetting of inputs for various control devices without requiring manual resetting of the input devices. In another aspect input means is provided to selectively reassign one set of physical input devices, such a rotary knobs, to various different controlled devices. The presentation of the input devices as virtual images with position indicators allows the real input panel to remain free of resettable position indicators, and input device position to be reliably indicated with excellent resolution. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a digital audio mixing console in the prior art. FIG. 2 is a partial view of input operating devices on the console of FIG. 1. FIG. 3 is a block diagram illustrating knob input operations in a digital console system. FIG. 4A shows one possible solution to the problem of knob position in snapshot recall. FIG. 4B shows a variation to the solution of FIG. 4A. FIG. 5A is an isometric view of an input panel with a display according to an embodiment of the invention. FIG. 5B is a block diagram of the input panel of FIG. 5A. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 5A shows an array of rotary knobs 53 adjacent a flat panel display 55 in a system 57 according to an embodiment of the present invention for providing digital signals to control audio mixing and processing equipment. The audio mixing and processing elements are not shown, and may be in a separate enclosure at some distance, and addressed by digital communication lines, such as a serial communication link. The display need not be a flat panel display, but such a display lends itself most conveniently to embodiments of the invention. In the example shown in FIG. 5A knobs 59 are arranged in a rectangular array 4 wide and three deep, for a total of 12 physical knobs. In the apparatus of FIG. 5A the knobs are digital inputs, typically implemented with shaft encoders, as in FIG. 3. FIG. 5B is a block diagram showing the general electronic arrangement of elements in system 57. Knobs 59 feed rotary information to CPU 61 which communicates on a bus 63 to RAM 65 to maintain position setting values for knobs 59 in operating registers 67. Snapshots signalled cause position settings in registers 67 to be stored in separate registers, such as registers 69, identified for later retrieval. The operating registers are used in the system to drive digitally responsive processing and mixing devices to accomplish the purposes of the audio engineer, which devices may, as described above, be located in a separate enclosure. In addition, the values of the operating registers are used in conjunction with stored control routines and data to drive display panel 55 to display an array 71 of virtual rotary knobs corresponding on a one-to-one positional basis to physical rotary knob array 53. In this unique solution to the position feedback problem described above, the operator manipulates physical knobs such as knob 59 in array 53, and the computerized system displays virtual corresponding knobs in array 71. The physical knobs need not have, and in this embodiment, do not have, indicators, either on the knobs or on the panel. Absolute indicators are indicated on both the virtual panel and knobs in the display. This arrangement allows the physical console to remain uncluttered, both as to legends and indicators. All legends and indicators are shown in the display, where they may be updated without having to manipulate any real hardware. The real time correspondence of the real and virtual knobs is such that as an operator manipulates (rotates) a real knob, such as upper left knob 59 (FIG. 5A), the geometrically corresponding knob 73 in the display is seen to rotate by a like amount, with a knob position indicator 75 changing position in apparently real time. As the virtual knobs are, in this embodiment, implemented as a full plan view (no shadowing), it is actually only necessary to move the knob position indicators to indicate knob rotation. Panel indicators, such as indicator 77 for virtual knob 73, do not move. In another embodiment there are no real input devices at all, and the virtual devices are manipulated by known methods of computer screen input, such as pointer devices and touch-sensitive screens. This implementation is seen to be less preferred in the art, because most audio engineers have developed a feel for "playing" the real devices. The embodiment described above, with real devices for input, and virtual devices for feedback, retains the feel for the operating engineer. In an alternative embodiment, the real and virtual knobs are color coded to increase the comfort of visual correlation for the operator engineer. The coding can be by any of a number of schemes, with the virtual knob carrying the same color as the real. In other embodiments, knob size, shape, and other visual indicators might be used as well. The invention is applicable as well to other than knobs, although all the advantages of the replication of knob inputs are not realized. For example, an array of pushbuttons may be replicated, or pushbuttons along with knobs or other input devices, with the state of the pushbutton switches indicated in the virtual array. This allows for use of real pushbuttons without internal LEDs to indicate state, and for snapshots to be retrieved for pushbutton states as well as knob positions. Slide rheostats (faders) may also be replicated, but this implementation suffers from the drawback that the actual physical faders will be in a different position than the virtual after retrieval of a snapshot. In this case the operator has to move the physical faders to the retrieved indicated position, and the equivalence may be signalled with visual, auditory, or even sensual indication. The virtual replication of input indicators has another dimension beyond solving the feedback problem for snapshot retrieval. That is that the correspondence of input devices to audio processing and mixing equipment may be selectable. In an audio mixing console as shown in FIG. 1, there are typically multiple channels assigned by such as patch cords to individual or grouped audio inputs. For example, in an application for an instrumental group, lead guitar may be assigned to Channel 1, base to Channel 2, keyboard to channel 3, etc. Each of the channels typically has a similar array of input devices assigned to particular processing devices. For example, a single channel may have a one or more bar graph meters assignable to various sources, an input amplifier controlled by certain input devices, filters, one or more faders, and other associated processing and mixing equipment. In the embodiment shown in FIG. 5A, the one set of physical input devices may be assigned selectively to different channels by pressing one of attention keys 79, and to a function within a channel by pressing one of attention keys 81. When selection is made, the display changes to show the "current" setting for the particular function in the particular channel selected, and a caption or other legend, such as caption 83, changes to indicate the channel and function selected. In this case the selection of Channel 5 EQ (for equalizer) is shown. By this feature of the invention, an entire sophisticated mixer console may be implemented by a single array of input devices, and a single display, while still retaining all of the necessary feedback ability and the physical feel of manual manipulation for "playing" the board. It will be apparent to those with skill in the art that there are many alterations that may be made without departing from the spirit and scope of the invention. For example, there are many different ways that input devices may be grouped in a real panel, and the number may change for many reasons from just one to a much larger number. The nature of both the input devices and the virtual displays of them may also be done in a wide variety of ways. Specifically, different manufacturers and developers favor different groupings of input devices, generally duplicated in a channel scheme, but any such grouping is amenable to the separation of physical manipulation and visual feedback as described above for embodiments of the invention.	A control panel for digital input having multiple rotary knobs without absolute minimum and maximum settings feeds knob position information back to an operator by providing a display of the knobs with position indicators. The display is updated according to real adjustment of the knobs. This arrangement allows the knobs to be assigned to different inputs and the apparent positions of the knobs to be changed without requiring moving the real knobs. In a preferred embodiment the control system is applied to an audio mixer panel.	8
BACKGROUND OF THE INVENTION The present invention relates generally to controllers for a combustion system for a gas turbine. In particular, the invention relates to a combustor control algorithm for a Dry Low NOx (DLN) combustor. Industrial and power generation gas turbines have control systems (“controllers”) that monitor and control their operation. These controllers govern the combustion system of the gas turbine. To minimize emissions of carbon-monoxide and nitric-oxides (NOx), DLN combustion systems may include control scheduling algorithms that receive as inputs measurements of the exhaust temperature of the turbine, the actual operating compressor pressure ratio, and the actual emissions levels. Emissions sensors are needed to monitor emission levels in the turbine exhaust. Industrial gas turbine engine control systems generally employ triplex redundancy for control process and safety critical sensors. Triplex redundancy is often needed to satisfy safety and reliability expectations and requirements of customers and governmental agencies. Providing three emission sensors for a turbine exhaust is expensive, and adds to the maintenance and calibration requirements of the gas turbine. There is a need for a cost effective approach to directly controlling emission levels in a gas turbine. BRIEF SUMMARY OF THE INVENTION The invention may be embodied as a method for determining an estimated operating parameter for a gas turbine including the steps of: determining an estimated operating parameter using an algorithm have an input from a sensor, wherein the algorithm includes a trim factor; determining a first trim factor based on a comparison of the first estimated operating parameter and the output of the sensor when a condition of the sensor is in a first mode, and during a subsequent determination of the estimated operating parameter, applying the first trim factor to subsequently determine the estimated operating condition if the condition of second sensor is in a second mode. The invention may also be embodied as a method for determining an estimated operating emission level in the exhaust stream of a gas turbine comprising: periodically determining an estimated emission level from an output of emissions transfer algorithm, wherein said algorithm includes a trim factor; determining a current trim factor based on a ratio of a current output of a healthy emission sensor monitoring the exhaust and of the estimated emission level from a prior determination, and applying a prior trim factor previously applied to determine the estimated operating condition if the emission sensor is unhealthy. The invention may be further embodied as a system for determining an estimated operating parameter for a gas turbine having an exhaust and a fuel controller comprising: a controller including a processor executing a combustion temperature scheduling algorithm and emissions transfer function stored in electronic memory of the controller, wherein said scheduling algorithm outputs a temperature request signal applied to generate a fuel control command for said fuel controller and said scheduling algorithm receives as an input a trim factor based on an estimated emission level generated by the emissions transfer function, wherein said emissions transfer function includes a emissions correction factor; a emission sensor measuring a emission level in the exhaust, wherein said sensor has an operating mode and a suspended mode; a trim factor switch selectively operating said sensor in said modes, wherein said switch selects a current emissions correction factor or a prior emissions correction factor to be applied to the emissions transfer function on a sensor condition input signal applied to the switch. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings in conjunction with the text of this specification describe an embodiment(s) of the invention. FIG. 1 is a schematic depiction of a gas turbine having a fuel control system. FIG. 2 is a block diagram of an emission limiting system including a closed-loop control temperature scheduling algorithm to trim a reference exhaust temperature request applied to control the gas turbine. FIG. 3 is a block diagram of a conventional emissions-trim temperature scheduling algorithm. FIG. 4 is a block diagram of a emissions-trim temperature scheduling algorithm having a emission model-based trim factor. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 depicts a gas turbine 10 having a compressor 12 , combustor 14 , turbine 16 drivingly coupled to the compressor and a control system 18 . An inlet duct 20 to the compressor feeds ambient air and possibly injected water to inlet guide vanes (IGVs) 28 and to the compressor. The turbine may drive a generator 22 to produce electrical power. The operation of the gas turbine may be monitored by several sensors 24 detecting various conditions of the turbine, generator and environment. For example, temperature sensors may monitor compressor discharge temperature, turbine exhaust gas temperature, and other temperature measurements of the gas stream through the gas turbine. Pressure sensors may monitor static and dynamic pressure levels at the compressor inlet and outlet, and turbine exhaust, as well as at other locations in the gas stream. The sensors 24 may also comprise flow sensors, speed sensors, flame detector sensors, valve position sensors, guide vane angle sensors, or the like that sense various parameters pertinent to the operation of gas turbine 10 . Typically, pressure, temperature, flow, speed, IGV and many other sensors on a gas turbine are extremely reliable, require infrequent calibration and maintenance and are inexpensive, at least as compared to some of the more recent emission sensors that are available for monitoring emissions. As used herein, “parameters” and similar terms refer to items that can be used to define the operating conditions of turbine, such as temperatures, pressures, and flows at defined locations in the turbine that can be used to represent a given turbine operating condition. The controller may be a General Electric SPEEDTRONIC™ Gas Turbine Control System, such as is described in Rowen, W. I., “SPEEDTRONIC™ Mark V Gas Turbine Control System”, GE-3658D, published by GE Industrial & Power Systems of Schenectady, N.Y. The controller 18 may be a computer system having a processor(s) that executes programs to control the operation of the gas turbine using sensor inputs and instructions from human operators. The programs executed by the controller 18 may include scheduling algorithms for regulating fuel flow to the combustor 14 and the angle of the inlet guide vanes (IGV). The commands generated by the controller cause a fuel controller 27 on the gas turbine to, for example, adjust valves 31 between the fuel supply and combustors that regulate the flow and type of fuel, and actuators 29 to adjust the angle of the IGVs 28 on the compressor. The controller 18 regulates the gas turbine based, in part, on algorithms stored in computer memory of the controller. These algorithms enable the controller 18 to maintain the NOx and CO emissions in the turbine exhaust to within certain predefined limits, and to maintain the combustor firing temperature to within predefined temperature limits. The combustor 14 may be a DLN combustion system. The control system 18 may be programmed and modified to control the DLN combustion system. Gas turbine engines with ultra-low emissions combustors, e.g., DLN combustion systems, require precise control so that the turbine gas emissions are within limits established by the turbine manufacturer, and to ensure that the gas turbine operates within certain operability boundaries, e.g., lean blowout, combustion dynamics, and other parameters. Control systems for ultra-low emission combustors generally require highly accurate and calibrated emission sensors. In the past, calibration of these sensors required field service engineers to regularly adjust settings on the controller and emissions sensors to accommodate changes in the operation of the gas turbine due to wear and other conditions. Conventional closed-loop systems employ emission sensors to measure emissions levels in the turbine exhaust and provide feedback data used by control algorithms. For example, emissions sensors at the turbine exhaust provide data on current emissions levels that is applied in determining a turbine exhaust temperature request. Emissions sensors are expensive, have relatively large processing delay (on the order of minutes), can be unreliable, and generally require frequent calibration and maintenance. The expense, delay, reliability, maintenance, and calibration issues associated with emissions sensing equipment pose unique problems for a closed-loop approach. Operation of an industrial gas turbine engine requires the control system to set the total fuel flow, compressor inlet guide vane (IGV), inlet bleed heat (IBH), and combustor fuel splits to achieve the desired cycle match point (i.e. generate the desired output and heat-rate while observing operational boundaries). Total fuel flow and IGV position are dominant effectors in achieving the desired result. A typical part-load control mode involves setting fuel flow and the IGV angle to satisfy the load (generator output) request, and to observe an exhaust temperature profile (temperature control curve). When base-load operation is achieved, the IGV is typically at an angle of maximum physical limit. At base-load, fuel flow alone is generally adjusted to observe an exhaust temperature profile needed to satisfy emission limits and other gas turbine operating limits. FIG. 2 shows a high-level block diagram of an exhaust temperature controller 30 . At this high level, the controller appears as a conventional exhaust temperature controller. Sensors and surrogates are provided to a temperature scheduling algorithm 32 to define an exhaust temperature request 34 . The temperature scheduling algorithm 32 receives input signals regarding the operation conditions of the gas turbine directly from sensors and from surrogates. Sensor signals provide data regarding parameters of the gas turbine that are directly monitored by the sensors. For example, temperature and pressure sensors may directly measure the temperatures and pressures at the gas turbine inlet, at various stages of the compressor and at the turbine exhaust. Similarly, speed sensors may measure the rotational speed of the gas turbine and flow sensors may measure the fuel flow into the combustor. Surrogates are parameters of the gas turbine that are not directly sensed, but are rather parameters determined based on algorithms and correlations based on sensor data regarding other operating conditions. The exhaust temperature request 34 is compared to an actual exhaust temperature level 36 to generate a difference signal 38 that is applied to a proportional integral compensation unit 40 which generates control values for operating the gas turbine. The control values may be inlet guide vane (IGV) settings and fuel settings that are applied to adjust the IGVs and to the fuel controller for the combustor of the gas turbine. The proportional integral compensation unit may be conventional. FIG. 3 depicts a conventional emissions-trim temperature scheduling algorithm 42 that includes a emissions trim function ( 49 , 50 and 52 ). A reference exhaust temperature 41 is determined based on the compressor pressure ratio (CPR) and a graph, look-up table or other correlation 46 that converts the CPR to the reference exhaust temperature 41 . The reference exhaust temperature 41 is trimmed (added to or subtracted from) by an output of a proportional plus integral (P+I) compensation algorithm 48 that outputs a trim value 47 to be summed with the reference exhaust temperature 44 . The trim value 47 is determined by the P+I unit based on a emission error value 49 which is a difference between a target emission value 50 and a sensed emission level 52 that is measured by emissions sensors 54 , e.g., NOx sensors. Given the need for triple redundancy in critical components, three emissions sensors 54 are employed in a conventional emissions-trim temperature scheduling algorithm. The trimmed reference exhaust temperature 44 is compared to a maximum allowable exhaust temperature in a minimum check algorithm 56 generate an exhaust temperature request 58 . The difference 60 between the reference exhaust temperature 44 and the exhaust temperature request 58 is used to reset the integral part of the P+I unit 48 to guard against integrator wind-up. Generally, the emissions trim function has only limited authority to guard against sensor failure or extreme sensor drift. If the emissions sensors fail or become uncalibrated, the emissions control system may become disabled. Industrial gas turbine engine control systems generally employ triplex redundancy for control process and safety critical sensors. Triplex redundancy is often needed to satisfy safety and reliability expectations and requirements of customers and governmental agencies. Providing three emission sensors 54 for a turbine exhaust can be extremely expensive, and increase the maintenance requirements of the gas turbine. If a closed-loop control system for emission could be relieved of the requirement for triple redundancy in sensor signals and only a single emissions sensor employed, then significant product cost could be avoided and the maintenance requirements reduced. However, employing an emissions sensor in a conventional closed-loop fashion places a significant system safety and reliability burden on that sensor. The processing delay inherent with stat-of-the-art emissions sensing equipment is typically on the order of several minutes. Emissions compliance requirements will typically allow short periods of non-compliance (on the order of seconds), but not significant periods of non-compliance. The time delay associated with emissions sensing equipment is such that the sole reliance on the sensor is not sufficient to ensure compliance when operational and environmental conditions are changing. Emissions sensors 54 must be regularly maintained to ensure that they are operating properly and that emission levels do not exceed allowable limits. In particular, emissions sensing equipment requires frequent calibration to ensure accuracy in emission measurements. Sensor drift is usually caused by changes in ambient temperature. If only a single sensor is employed in the control system shown in FIG. 3 , then special operational restrictions would necessarily be placed on the gas turbine while the sensor was being calibrated. Such operational restrictions would be required to avoid violation of gas system operability boundaries, and would have a negative impact on the continuous operation of the gas turbine. Where there is a single emission sensor failure of that one sensor can result in the benign problems (such as non-compliance with emissions requirements, slight over or under-fire) and serious problems (blow-out, trip, failure). A method is needed to reduce the cost of closed-loop control of emissions that does not sacrifice system safety and reliability, and does not impose operational restrictions on the operation of the gas turbine. FIG. 4 depicts a closed loop, model-based emissions-trim temperature scheduling algorithm 70 that generates an estimated emission level 72 that is applied to trim 47 an exhaust temperature request 41 . The estimated emission level 72 is used instead of the sensed emission level 52 of the conventional system shown in FIG. 3 . In the emissions model-based algorithm, the closure of the emission control system 70 is performed on an estimated emissions level 72 that is the output of a physics-based emissions transfer function 74 . The emissions transfer function 74 receives as inputs data from sensors and surrogates, such as, compressor discharge temperature, specific humidity of ambient air, fuel split ratio and firing temperature. The transfer function 74 models the relationship between emissions and the cycle match point of the gas turbine. The sensors 24 used to generate the sensor data and the surrogates data for the emissions transfer function may be conventional sensors, e.g., temperature pressure and specific humidity sensors, that are typically used with a gas turbine and which are typically triple redundant. The emissions transfer function 74 is tuned (K) to match a sensed emission level 76 , when the emissions sensor 78 is deemed to be “healthy.” The correction factor (K) that is applied to the emissions transfer function to adjust the estimated emission level 72 . The correction factor (K) is determined from a comparison, e.g., ratio, of the estimated emissions value 72 to a sensed emissions value 76 . In the example shown here, the correction factor (K) is a ratio of the estimated emissions value for a preceding determination (Z −1 ) by the emissions transfer function 74 and the sensed emissions value 76 . The emissions transfer function 74 determines the estimated emissions level 72 periodically, such as every compute cycle of the controller (40 ms). A correction factor (K) of 1.0 indicates that the estimated emissions and sensed emissions values are the same. The extent to which the correction factor K is smaller or greater than 1.0 indicates the extent to which the estimated emissions value differs from the sensed emissions value. The correction factor need not be a ratio. It may be a difference between the estimated and sensed emissions values, or determined by a look-up table or function. For example, further, the correction factor (K) need not be a constant, but may be vary exponentially or a function of another parameter. There may be multiple correction factors applied to the emissions transfer function based on a multitude of accumulated data. A sensor condition signal 80 is provided that indicates whether the emissions sensor 78 is “healthy” or “unhealthy”. A healthy emissions sensor may be a sensor that is operating within an expected range and is not undergoing calibration. The conditions for which a sensor is deemed healthy may be determined for each gas turbine or class of gas turbines. For example, the sensor condition signal may be set to “healthy” if the sensor is not currently undergoing maintenance and calibration, the gas turbine has not recently changed its operating conditions, and the sensor is operating within the expected range. The sensor 78 may be a single NOx emissions sensor and the transfer function 74 may predict a NOx emissions level. When the sensor 78 is deemed to be un-healthy, the tuning process is switched 82 (F) to suspend the emissions sensor and apply a previous value 84 (Z −1 of K) of the correction factor (K). This previous K-value is maintained until sensor health is restored. The switch 82 determines whether the correction factor (K) is a prior K-value 84 or a value determined from the actual emission level currently sensed by the emissions sensor 78 . The switch 82 may also suspend the operation of the emissions sensor, while a prior K-value us applied to the emissions transfer function 74 . The prior value 84 of K is repeatedly used as the correction factor for the trim temperature function 70 until the switch 82 is reset by a signal 80 that the sensor is healthy. The switch 82 may hold the emissions sensor 78 in an suspended mode during steady state operation of the gas turbine and while ambient conditions, e.g., specific humidity remain relatively constant; while the emissions sensor is being calibrated, and while the sensor is producing out of range levels. By suspending emission sensing during extended periods of gas turbine operation, the emissions sensor 78 requires less frequent maintenance and calibration and the amount of wear on the sensor is reduced. The model-based approach reduces the emission system dependency on the single emissions sensor 78 by only periodically using the sensor to tune the correction factor (K). At other times, the same correction factor 84 is reused by the control-resident physics-based emissions transfer function 74 . The correction factor (K) may be applied (while the switch is set to F) even if the emissions sensor 78 has failed or is out of calibration. The use of an estimated emission level and a correction factor (K) that is periodically tuned using a emissions sensor maintains the overall gas turbine system safety and reliability, while simultaneously providing relief from the need for triple redundant emissions sensors. The dependency on redundant sensors is shifted to existing triple redundant gas turbine sensors, e.g., compressor discharge temperature (TCD), compressor discharge pressure (PCD), temperature sensors (Tx), and output power sensors. With the model-based approach for the emission level, the need is lessened to impose operational restrictions to accommodate emissions sensor calibration is, and there is less risk of gas turbine operating limit boundary violations resulting from emissions sensor failures. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.	A method for determining an estimated operating parameter for a gas turbine including the steps of: determining an estimated operating parameter using an algorithm have an input from a sensor, wherein the algorithm includes a trim factor; determining a first trim factor based on a comparison of the first estimated operating parameter and the output of the sensor when a condition of the sensor is in a first mode, and during a subsequent determination of the estimated operating parameter, applying the first trim factor to subsequently determine the estimated operating condition if the condition of second sensor is in a second mode.	8
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority under 35 U.S.C. § 119 to European Patent Application EP 05292702, filed Dec. 15, 2005, which is incorporated herein by reference in its entirety. [0002] 1. Field of the Invention [0003] The present invention is directed to a powder coating composition providing a coating system which is suitable for coil coating of substrate surfaces, which is a significant improvement over the systems of prior art in that they present health advantages. [0004] 2. Description of Prior Art [0005] Coil coating of substrates is a process of coating strips or sheets of, e.g., metal that are in the shape of coils, with liquid or powder coating compositions. In general, such coils are being un-wound, and are cleaned or pre-treated, then coated, cured in an oven, cooled down and are wounded again. This process proceeds under high speed, e.g., at coating speeds of, for example, >50 m/min. [0006] Powder coating compositions are being used more and more for that kind of coating process. Especially thermosetting powder compositions are used based on polyesters as binder resin and typical curing agents such as solid polyepoxides, for example, triglycidyl isocyanurate (TGIC). [0007] The polyester/TGIC system gives coatings with good properties for outdoor use, especially for the coating of metal substrates such as weather durability and chemical resistance as well as fast curing of the coating and flexibility of the cured coating. [0008] The problem arising with these systems is the high toxicity of TGIC, a product of mutagenic character apart from being irritant to the skin and the mucosae, toxic on inhalation, and the like. This compels the introduction of robust safety measures from the standpoint of the health of the workforce, the personnel having to be appropriately protected and to submit to the appropriate medical checks, thereby entailing substantial costs in addition to the already high cost of TGIC. [0009] Accordingly, there is a need to replace this polyester resin/TGIC system by other, less harmful and globally less expensive systems. [0010] There are numerous patents in which the use of organic peroxides as curing initiator or agent is described for different types of resins, e.g., JP 49128939, JP 49040348, JP 55025462, DE2332749, JP 54150440, JP 55027307, JP 56100870, JP 55003416, JP 54158440, JP 52150443, JP 49129725, JP-04/227713 and JP 49093425. Such formulations are not suitable for coil coating processes. [0011] In the article “Rund um TGIC-freie Pulverlacke” (Th. Brock, Farbe&Lack, volume 106, 2/2000, pages 38 to 44) alternatives of TGIC substitutes are named such as polyurethanes, anhydrides+glycidylmethacrylate and hydroxyl alkyl amides. The TGIC-free powder coats may have good coating properties but show difficulties regarding weatherability resistance, generating pin holes and problems regarding balance of flow and sagging properties, low storage stability. [0012] There is a need to provide coating compositions suitable for coil coating applications which overcome the drawbacks of toxicity presented by TGIC and of disadvantages presented by the TGIC alternatives, and which may be cured at a short time. SUMMARY OF THE INVENTION [0013] The present invention provides a powder coating composition comprising (A) 40 to 99 wt % of at least one saturated carboxylic functional polyester resin, having an acid value in the range 5 to 200, (B) 1 to 60 wt % of at least one glycidylester and/or glycidylether selected from the group consisting of polyglycidyl ethers based on aliphatic, aromatic and/or cycloaliphatic epoxy resins, triglycidyl trimellitate (TML) and diglycidyl terephthalate (DGT), and (C) 0.01 to 40 wt % of at least one coating additive, pigment and/or filler, [0017] the wt % being based on the total weight of the powder coating composition. [0018] In spite of substitution of TGIC, the powder coating composition of this invention are coating compositions having a good storage stability and giving coatings with good coating properties, particularly, high exterior durability and stable flexibility. Surprisingly, the disadvantages caused by the known TGIC substitutes such as pin holes and gassing of the coating may be prevented. The composition of the invention fulfils the requirements of health and safety classification in Europe, e.g., is not classified as “Toxic” according to the European Chemicals Regulations in particular R46 (R46 phrases: May cause heritable genetic damage). [0019] The powder coating compositions according to the invention is especially suitable for the coil coating technology, that means, for coating applications also under high speed, e.g., at coating speeds of >50 m/min providing coatings with a high flexibility under post forming. DETAILED DESCRIPTION OF THE INVENTION [0020] The features and advantages of the present invention will be more readily understood, by those of ordinary skill in the art, from reading the following detailed description. It is to be appreciated those certain features of the invention, which are, for clarity, described above and below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any sub-combination. In addition, references in the singular may also include the plural (for example, “a” and “an” may refer to one, or one or more) unless the context specifically states otherwise. [0021] The slight variations above and below the stated ranges of numerical values can be used to achieve substantially the same results as values within the ranges. Also, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum values. [0022] All patents, patent applications and publications referred to herein are incorporated by reference in their entirety. [0023] Suitable polyester resins as component A) are saturated carboxylic functional polyester resins. They have an acid value in the range of 5 to 200, preferably 15 to 100, especially preferred 15 to 60, [0024] The acid value is defined as the number of mg of potassium hydroxide (KOH) required to neutralise the carboxylic groups of 1 g of the resin. [0025] The polyesters may be produced in a conventional manner by reacting of one or more aliphatic, aromatic or cycloaliphatic di- or polycarboxylic acids, and the anhydrides and/or esters thereof with polyalcohols, as is, for example, described in D.A. Bates, The Science of Powder Coatings, volumes 1 & 2, Gardiner House, London, 1990, and as known by the person skilled in the art. [0026] Examples of suitable polycarboxylic acids, and the anhydrides and/or esters thereof include maleic acid, fumaric acid, malonic acid, adipic acid, 1.4-cyclohexane dicarboxylic acid, isophthalic acid, terephthalic acid, acrylic acid, and their anhydride form, or mixtures thereof. Examples of suitable alcohols are benzyl alcohol, butanediol, hexanediol, ethylene glycol, diethylene glycol, pentaerytritol, neopentyl glycol, propylene glycol, and mixtures thereof. [0027] The saturated carboxyl group containing polyesters may be used together with small amounts of hydroxyl group containing polyesters, for example, 0 to 10 wt % of hydroxyl group containing polyesters having a hydroxyl value of, for example, 10 to 200, [0028] Preferred is the use of saturated carboxyl-functionalized polyesters without any addition of hydroxyl group containing polyesters. [0029] The polyester resins may have a glass transition temperature Tg in a range of, e.g., 35 to 80° C., preferably 50 to 75° C., Tg determined by means of differential scanning calorimetry (DSC). The number average molecular weight Mn of the resins is in the range of, e.g., 2,000 to 10,000, Mn determined from gel permeation chromatography (GPC) using polystyrene standard. [0030] Crystalline and/or semicrystalline saturated carboxylic functional polyester resins are also usable which have a Tm (melting temperature) in the range of e.g., 50 to 150° C., determined by means of DSC. [0031] The polyesters of the invention can also be partially self cross-linkable polyesters containing cross-linkable functional groups known by a person skilled in the art. [0032] Component B) of this invention is used as hardener of Component A). Glycidylesters and/or glycidylethers may be used as component B) selected from the group consisting of polyglycidyl ethers based on aliphatic, aromatic and/or cycloaliphatic epoxy resins, TML and DGT. Preferred is the use of TML and DGT in solid form. [0033] The polyglycidyl ethers based on aliphatic, aromatic and/or cycloaliphatic epoxy resins can be used which are known in the powder coating area. [0034] The hardeners of the invention may be used together with small amounts of other suitable hardeners known by the person skilled in the art, for example, blocked polyisocyates such as, e.g., aliphatic diisocyanates, for example, in quantities in the range of 0 to 10 wt %. [0035] The content of the polyester resin (A) may be in a range, for example, preferably between 40 wt % and 95 wt %, particularly in the range of 50 wt % to 90 wt %. [0036] The content of the hardener (B) may be, for example, preferably in a range between 2 wt % and 30 wt %, particularly in the range of 3 to 20 wt %. [0037] The powder coating composition may contain as further components the constituents conventional in powder coating technology, such as, additives, pigments and/or fillers as known by a person skilled in the art. [0038] Additives are, for example, degassing auxiliaries, flow-control agents, flatting agents, texturing agents, fillers (extenders), catalysts, dyes, anti-oxidant, anti-UV, tribostatic or corona electrostatic charging auxiliaries. Compounds having anti-microbial activity may also be added to the powder coating compositions. [0039] The crosslinking reaction may be additionally accelerated by the presence in the powder coating composition according to the invention of catalysts known from thermal crosslinking. Such catalysts are, for example, tin salts, phosphides, amines, ammonium salts, cyclic amidines, phosphonium salts, alkyl- or aryl-imidazolines and amides. They may be used, for example, in quantities of 0.02 to 3 wt %, based on the total weight of the powder coating composition. [0040] The powder coating composition may contain transparent, color-imparting and/or special effect-imparting pigments and/or fillers (extenders). Suitable color-imparting pigments are any conventional coating pigments of an organic or inorganic nature considering their heat stability which must be sufficient to support the curing of the powder coating composition of the invention. Examples of inorganic or organic color-imparting pigments are titanium dioxide, micronized titanium dioxide, carbon black, azopigments, and phthalocyanine pigments. Examples of special effect-imparting pigments are metal pigments, for example, made from aluminum, copper or other metals, interference pigments, such as, metal oxide coated metal pigments and coated mica. Examples of usable extenders are silicon dioxide, aluminum silicate, barium sulfate, calcium carbonate, magnesium carbonate, micronized dolomite. [0041] The constituents are used in conventional amounts known to the person skilled in the art, for example, based on the total weight of the powder coating composition, regarding pigments and/or fillers in quantities of 0 to 40 wt. %, preferred 0 to 35 wt %, regarding the additives in quantities of 0.01 to 5%, preferred 1 to 3 wt %. [0042] The powder coating composition may be prepared by conventional manufacturing techniques used in the powder coating industry, such as, extrusion and/or grinding processes. [0043] For example, the ingredients used in the powder coating composition, can be blended together and the mixture is extruded. In the extruder the mixture is melted and homogenized, a dispersion of pigments is ensured by shearing effect. The extruded material is then cooled on chill roles, broken up and then ground to a fine powder, which can be classified to the desired grain size, for example, to an average particle size of 20 to 200 μm, preferred 20 to 50 μm. [0044] The powder coating composition may also be prepared by spraying from supercritical solutions, NAD “non-aqueous dispersion” processes or ultrasonic standing wave atomization process. [0045] Furthermore, specific components of the composition according to the invention, for example, additives, pigment, fillers, may be processed with the finished powder coating particles after extrusion and grinding by a “bonding” process using an impact fusion. For this purpose, the specific components may be mixed with the powder coating particles. During blending, the individual powder coating particles are treated to softening their surface so that the components adhere to them and are homogeneously bonded with the surface of the powder coating particles. The softening of the powder particles' surface may be done by heat treating the particles to a temperature, e.g., the glass transition temperature Tg of the composition, in a range, of e.g., 50 to 60° C. After cooling the mixture the desired particle size of the resulted particles may be proceed by a sieving process. [0046] The powder coating composition of this invention may be applied by, e.g., electrostatic spraying, thermal or flame spraying, or fluidized bed coating methods, all of which are known to those skilled in the art. [0047] The powder coating composition according to the invention is especially suitable for the coil coating technique at coating speeds of, for example, 5 to 50 m/min, also for high speed coating, at coating speeds of, for example, >50 m/min. [0048] Coil coating techniques such as cloud technology generated by rotating brush and electromagnetic brush technology (EMB) as well as other known application techniques like corona or tribostatic sprayer guns or rotative bells projectors are examples for the application by coil coating procedure as known by a person skilled in the art. For example, the metal sheets or strips may be disposed on a horizontal conveyor during coil coating. [0049] The coating compositions may be applied to, e.g., metallic substrates, non-metallic substrates, such as, paper, wood, plastics, glass and ceramics, as a one-coating system or as coating layer in a multi-layer film build. In certain applications, the substrate to be coated may be pre-heated before the application of the powder composition, and then either heated after the application of the powder or not. For example, gas is commonly used for various heating steps, but other methods, e.g., microwaves, conduction methods, Infrared (IR) radiation, near infrared (NIR) radiation, electrical induction heating are also known. Catalytic gas infrared ovens and electric infrared oven are commonly used, frequently coupled with gas convection ovens. [0050] The powder coating compositions according to the invention can be applied directly on the substrate surface or on a layer of a primer which can be a liquid or a powder based primer. The powder coating compositions according to the invention can also be applied as a coating layer of a multilayer coating system based on liquid or powder coats, for example, based on a powder or liquid clear coat layer applied onto a color- imparting and/or special effect-imparting base coat layer or a pigmented one-layer powder or liquid top coat applied onto a prior coating. [0051] The applied and melted powder coating layer can be cured by thermal energy. The coating layer may, for example, be exposed by convective, gas and/or radiant heating, e.g., infra red (IR) and/or near infra red (NIR) irradiation, as known in the art, to temperatures of, e.g., 100° C. to 300° C., preferably of 180° C. to 280° C. (object temperature in each case). [0052] If the composition according to the invention is used together with unsaturated resins and, optionally photo-initiators or with unsaturated resin containing powders, dual curing may also be used. Dual curing means a curing method of the powder coating composition according to the invention where the applied composition can be cured, e.g., both by high energy radiation such as, e.g., ultra violet (UV) irradiation, and by thermal curing methods known by a skilled person. [0053] The present invention is further defined in the following Examples. It should be understood that these Examples are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various uses and conditions. As a result, the present invention is not limited by the illustrative examples set forth herein below, but rather is defined by the claims contained herein below. [0054] The following Examples illustrate the invention. EXAMPLES Example 1 [0055] Manufacture of a Powder Coating Composition and Application [0056] A powder coating composition according to the invention is prepared using the following ingredients: Composition 1 Weight % URALAC ® P3485 (COOH polyester acid value 27) 81.7 Araldite ® PT 912 (mixture of TML and DGT) 7.0 REAFREE ® ND 1750 (mixture of COOH polyester, 6.6 acid value 27, and flow agent, in 90/10 ratio) DISPARLON ® PL 540 (Surface control agent based on 2.35 modified castor oil) BENZOINE 0.45 IRGANOX ® 1010 (anti oxidant) 0.95 ACCELERATEUR DT 3126-2 0.95 [0057] The ingredients of each composition are mixed and extruded in an extruder PR 46 (firm: Buss AG) at 120° C. The melt-mixed formulation is cooled and the resulted material is grinded to a D50 value of 30 μm particle size distribution. [0058] The final powder compositions are applied to a 0.8-mm metal sheet using the coil coating technology at a coil coating speed of about 40 m/min and cured by medium wave infrared electric emitters adjusted in such a way that the coated surface temperature increases from room temperature to 270° C. in 60 seconds (s), kept at 270° C. for 10 second and cooled down rapidly to room temperature. The total heating time is 70 seconds and the cooling time is 30 s by cool air. The resulted film thickness is of 45 μm. Example 2 [0059] Testing of the Coating TABLE 1 Flexibility Gassing Mechanical Properties (Postforming) (Pinholes, Visual Composition Impact Test ECCA T7 1996 observation) 1 more than 90% gloss O-T bends no retention without cracks The test results show very good mechanical properties, high flexibility without any gassing and cracking.	The present invention provides a powder coating composition comprising (A) 40 to 99 wt % of at least one saturated carboxylic functional polyester resin having an acid value in the range 5 to 200, (B) 1 to 60 wt % of at least one glycidylester and/or glycidylether selected from the group consisting of polyglycidyl ethers based on aliphatic, aromatic and/or cycloaliphatic epoxy resins, triglycidyl trimellitate (TML) and diglycidyl terephthalate (DGT), and (C) 0.01 to 40 wt % of at least one coating additive, pigment and/or filler, the wt % being based on the total weight of the powder coating composition. The powder coating composition provides a good storage stability and giving coatings with good coating properties, particularly, high exterior durability and stable flexibility. The compositions are suitable for the coil coating technology, that means, for coating applications also under high speed.	2
This application is a continuation of international application number PCT/EP2002/013324 filed on Nov. 26, 2002. The present disclosure relates to the subject matter disclosed in international application PCT/EP2002/013324 of Nov. 26, 2002, which is incorporated herein by reference in its entirety and for all purposes. BACKGROUND OF THE INVENTION The invention relates to a method for controlling an elevator installation with at least one shaft and with a number of cars which each have an associated drive and brake, it being possible to make at least two cars travel separately up and down along a common traveling path, a passenger entering a destination call with a travel destination by means of an input unit of a control device of the elevator installation disposed outside the at least one shaft and an allocation assessment then being performed for each car, the allocation assessments of all the cars being compared with one another and the destination call being allocated to the car with the best allocation assessment to serve it. The invention also relates to an elevator installation, in particular for carrying out the method, with at least one shaft and with a number of cars which each have an associated drive and brake, it being possible to make at least two cars travel separately up and down along a common traveling path, and with input units disposed outside the at least one shaft for entering a destination call and also with a control device for controlling the cars, it being possible for an allocation assessment to be carried out by means of the control device for the individual cars after each time a destination call is entered and for the destination call to be allocated to a car. In order to transport large number of persons and/or loads within a short time by means of an elevator installation, it is proposed in U.S. Pat. No. 6,360,849 to make two cars travel up and down along a common traveling path within a shaft. Outside the shaft a passenger can enter a destination call into a control device of the elevator installation, with which he indicates his travel destination. The control device then respectively carries out an allocation assessment for the two cars and allocates the destination call to the car with the best allocation assessment. It is an object of the present invention to develop a method of the type stated at the beginning in such a way that the transporting capacity can be increased and shaft space can be saved, with the cars which can be made to travel along a common traveling path hindering one another as little as possible. SUMMARY OF THE INVENTION This object is achieved in the case of a method of the generic type according to the invention by providing that, in the case of allocation of the destination call to one of the cars which can be made to travel along a common traveling path, the portion of the traveling path required by the allocated car to serve the destination call is assigned to this car and the assigned portion of the traveling path is blocked for the time of the assignment for the other cars which can be made to travel along the common traveling path. In the case of the method according to the invention, after entry of a destination call, an allocation assessment of the destination call is performed for each of the cars of the elevator installation that are in operation, in dependence on the operating data and the operating state of the respective car. On the basis of the allocation assessment, the destination call is then allocated to the car with the best allocation assessment, so that it can serve the destination call. If it is a car which is sharing a traveling path with at least one further car, it is provided according to the invention that the portion of the traveling path required for the allocated car to serve the destination call is assigned to this car, while it is blocked during the time of the assignment for the other cars which can be made to travel along the common traveling path. The portion of the traveling path required to serve the destination call is understood here as meaning the portion of the traveling path which, beginning from the current position of the car serving the destination call, extends via the starting point to the destination point of the travel desired by the passenger. This portion of the traveling path is consequently “reserved” for serving the destination call by the car to which the destination call is allocated, so that another of the cars which can be made to travel along the common traveling path cannot enter this portion of the traveling path during the time of the existing assignment, that is during the time in which the destination call is being served. The common traveling path is understood here as meaning a common traveling path of at least two cars within one shaft, that is a region of the shaft which is used for traveling along both by a first car and by at least a second car. Within this region it is possible that the at least two cars can be made to travel along common guide rails, but it may also be provided that the at least two cars have separate associated guide rails along the common traveling path. The use of at least two cars in one shaft allows shaft space to be saved and at the same time a high transporting capacity to be achieved. As mentioned at the beginning, the allocation assessments performed for each car are compared with one another, in order that subsequently the entered destination call can be allocated to the car with the best allocation assessment. It is of advantage here to exclude from the comparison of the allocation assessments those cars for which the portion of the traveling path respectively required for serving the current destination call overlaps at least partly a portion of the traveling path which has already been assigned to another car on the basis of an earlier, not yet served destination call. Before the comparison of the allocation assessments, in the case of a control method of such a form it is in the first instance checked for each of the cars which can be made to travel along a common traveling path whether the portion of the traveling path required for this car to serve the destination call overlaps a portion of the traveling path which has already been assigned to another of the cars which can be made to travel along the common traveling path. The current destination call could consequently not been served by this car which can be made to travel along the common traveling path, and this car is therefore excluded from the comparison of the allocation assessments of all the cars of the elevator installation. If the portion of the traveling path respectively required for serving a current destination call does not overlap any portion of the traveling path already assigned to a car, it is advantageous if in the first instance only the allocation assessments of the cars which can be made to travel along the common traveling path are compared with one another and then only the car with the best allocation assessment of these cars is used for the comparison with the allocation assessment of the remaining cars. Consequently, in the case of such a form of the method according to the invention, in the first instance an allocation assessment for the cars which can be made to travel along a common traveling path is only performed if the current destination call can in principle be served by all these cars. Of the cars which are sharing a common traveling path, then only the car with the best allocation assessment is used for the comparison with the allocation assessments of the remaining cars, while the other cars which can be made to travel along the common traveling path are excluded from this comparison. It has been found that, in the case of such a procedure, the allocation of an entered destination call to a specific car can be carried out particularly quickly. This makes it possible after a destination call has been entered to respond to a passenger within a very short time with a reply indicating which car and/or which shaft of the elevator installation he is to use to reach his entered travel destination. If the current destination call can in principle be served by all the cars which are sharing a common traveling path, it is advantageous if each of these cars is provisionally assigned the portion of the traveling path required to serve the current destination call, then the results of the allocation assessments of these cars are compared with one another and then the provisional assignment of the portions of the traveling path is revoked with the exception of the car with the best allocation assessment, and, when the current destination call is allocated to the car which can be made to travel along the common traveling path that has the best allocation assessment of these cars, this car is definitively assigned the respective portion of the traveling path and, when the current destination call is not allocated to this car, its provisional assignment of the respective portion of the traveling path is cancelled. In the case of such a procedure, the assignment of a portion of the traveling path to one of the cars which can be made to travel along a common traveling path takes place in two stages, as long as the current destination call can in principle be served by each of these cars. In a first stage, each of these cars is provisionally assigned the portion of the traveling path respectively required for serving the destination call. Subsequently it is checked which of the cars sharing a common traveling path has the best allocation assessment. Its provisional assignment remains in existence until the current destination call has been allocated to a car, while the provisional assignments of the other cars are revoked as soon as it is established which of the cars sharing a common traveling path has the best allocation assessment. If the destination call is finally allocated to the car which shares its traveling path with other cars, then in the second allocation stage the portion of the traveling path required for this car is definitively assigned to the car. If the allocation of the current destination call is made to a car which does not share its portion of the traveling path with a further car, the provisional assignment of the car which can be made to travel along a common traveling path is cancelled. Consequently once the allocation of an entered destination call has been made there is a clear situation for the cars which can be made to travel along a common traveling path to the extent that either a portion of the common traveling path has been assigned to one of the cars or else the current destination call does not result in any “reservation” of a portion of the traveling path for the cars which can be made to travel along a common traveling path. As already explained, in the case of a preferred embodiment of the method according to the invention it is provided that, after a destination call has been entered, the portion of the traveling path respectively required for serving the destination call is provisionally assigned to the cars which can be made to travel along a common traveling path, in order subsequently to compare the allocation assessments of these cars with one another. In this respect it has proven to be advantageous to exclude from the comparison of the allocation assessments of the cars which can be made to travel along a common traveling path those cars for which the portion of the traveling path respectively required for serving a current destination call overlaps at least partly a portion of the traveling path which has been provisionally assigned to one of the cars which can be made to travel along the common traveling path on the basis of an earlier destination call not yet allocated to a specific car. In the case of such a procedure, it is checked for the cars which can be made to travel along a common traveling path before the comparison of their allocation assessments whether there already exists a provisional assignment of a portion of the traveling path which would be overlapped when a current destination call is served by the portion of the traveling path required for this purpose. If this is the case, the respective car is no longer considered in the allocation of the current destination call, that is to say it is excluded from the comparison of the allocation assessments of the cars. In the case of a particularly preferred embodiment of the method according to the invention, a portion of the traveling path which has been assigned to a car is released again floor by floor for the other cars when the destination call is served. As a result, the freedom of movement of the cars which can be made to travel along the common traveling path can be increased, since, during the serving of a destination call, the portion of the traveling path assigned to one of these cars is released floor by floor as soon as the car serving the destination call has left the respective floor. If the elevator installation is used in a building which is occupied in such a way that, starting from a particularly frequented floor, for example a parking deck, the occupancy of the building takes place both upward and downward, it has proven to be advantageous if at least one of the cars which can be made to travel along a common traveling path is assigned a preferential region of the common traveling path and the position of the portion of the traveling path required for serving a destination call in relation to the respective preferential region is taken into consideration in the allocation assessment. This makes it possible for the traveling path shared by a number of cars to be divided up in such a way that one of the cars serves an upper part of the building with preference and another car serves a lower part of the building with preference, without excluding the possibility that, in the event of high user frequency of the lower part of the building, the car serving the upper part of the building with preference will also serve this lower part of the building. It is advantageous if the preferential regions of the cars which can be made to travel along a common traveling path are assigned to the cars in such a way that mutually neighboring preferential regions overlap, at least on the level of one floor. This has the consequence that this floor, for example a parking deck, can be served with the same priority by at least two cars. As an alternative, the preferential regions may be assigned to the cars without any overlap. For example, it may be envisaged for neighboring preferential regions to follow on directly from one another. At the interface of the two preferential regions, a double floor may be provided, so that a passenger starting from the double floor can select an upper preferential region or a lower preferential region, depending on whether he wishes to travel up or down. The allocation assessment of the individual cars for serving a destination call may take place situation-dependently, that is to say dependent on the number of destination calls in existence at a time. As an alternative, the allocation assessment may be performed in dependence on the capacity utilization of the cars. Such an assessment permits what is known as “filling transport”, which is aimed at distributing as many passengers as possible around a building in as short a time as possible from particularly frequented stops. For this purpose, it may be provided for example that the cars remain with open doors at an access stop, until either an adjustable load threshold of the cars is exceeded or an adjustable standing time has elapsed. This achieves the effect that the cars are better filled and consequently a higher transporting capacity is available. Such an allocation assessment may take place in a manner dependent on the time of day. For example, it may be provided that, on work days between 7 and 9 a.m., a utilization-dependent allocation assessment is carried out, with the access floor of the building, that is for example the first floor or a parking deck, being prescribed as the access stop of the cars. During the rest of the day, a situation-dependent allocation assessment may then be performed. It may also be provided that a further utilization-dependent allocation assessment is performed on work days, for example in the time between 12:30 and 1:30 p.m., with a canteen floor being prescribed as the access stop. In this way it is ensured that the users can leave the floor on which the canteen is located within a short time after visiting the canteen. It is advantageous if the travel destinations of the car next arriving at the respective floor is indicated on an indicating device on the floors to be served by the elevator installation. In this way, the user receives an indication of which destinations are being served by the car next arriving at the floor. This has the advantage that, after entering his destination call, a user can check before entering the car whether it is the desired car for reaching his travel destination. Furthermore, such an indication makes it possible that a passenger need not necessarily enter a destination call if his travel destination coincides with one of the destinations already indicated. The passenger can consequently enter the car arriving straight away, eliminating the time taken up by entering the travel destination, whereby the transporting capacity of the elevator installation can once again be increased. It may also be provided that not only the travel destinations of the car next arriving at the respective floor are indicated, but also the travel destinations of at least one further car arriving thereafter. It is of particular advantage if, after a destination call has been entered, the expected time before the arrival or departure of the car serving the destination call is indicated. The passenger consequently obtains an indication of the expected waiting time. After a destination call has been entered, it is provided in a preferred embodiment of the method according to the invention that, on an indicating unit associated with the input unit, the passenger is provided with an indication of the car allocated for serving his destination call. The passenger is consequently clearly allocated a quite specific car. If a number of cars can be made to travel along a common traveling path in one shaft, it may be provided for example that the cars are differently colored to distinguish between them. As an alternative, in the case of an elevator installation with a number of shafts, it may be provided that the shaft with the stop at which the car serving the destination call will arrive next is indicated to the passenger on an indicating unit associated with the input unit. Such a procedure has the advantage that, after a destination call is entered, a destination call allocation performed in the first instance to a specific car can also be changed after the response to the passenger. It must simply be ensured after the response has been made to the passenger that the next car arriving at the stop of the shaft indicated serves the destination call which has been entered. It is of particular advantage if each car has an associated control unit with a group control function, the control unit performing the allocation assessment for the associated car and all the control units being electrically connected to one another. Such a procedure makes it possible for the operation of the elevator installation to be particularly immune to faults, since it is possible to dispense with a higher-level central unit for controlling the cars. Rather, the control of all the cars can be performed with the aid of the decentralized control units, which respectively have a group control function. For this purpose, all the control units of the elevator installation are connected to one other in a wire-bound or wireless manner and all the cars are controlled by their interaction. The allocation assessment is performed by each control unit for the respectively associated car, and the results of the allocation assessments can be transmitted via the electrical connection to all the control units, so that the comparison of the allocation assessments can be performed by all the control units simultaneously. That control unit which detects on the basis of the comparison that the car associated with it has the best allocation assessment allocates the current destination call to itself and sends a corresponding allocation reply to the control unit which has read in the destination call. The other control units detect on the basis of their calculation that the destination call currently waiting to be served has been undertaken by the one control unit and the car associated with it. As an alternative and/or in addition, it may be provided that at least the cars which can be made to travel along a common traveling path have an associated central group control unit, which can perform the allocation assessment of all the associated cars. If the group control unit is used in addition to the decentralized control units, the group control unit need not be of a redundant configuration, since, if it fails, the control of the cars and the allocation assessment are taken over by the decentralized control units. The group control unit preferably has a considerably higher computing capacity than the decentralized control units. This provides the possibility of detecting behavioral patterns of the passengers by means of the central group control unit, in order to be able to perform a corresponding allocation assessment of the cars. In particular, the central group control unit can perform by means of methods of “artificial intelligence” known per se a predictive allocation assessment, in order to be able to provide as high a transporting capacity as possible in dependence on the behavioral pattern of the passengers. The invention also relates to an elevator installation, in particular for carrying out the method explained above, with the features stated at the beginning. To develop such an elevator installation in such a way that an improved transporting capacity can be achieved, with the cars which can be made to travel along a common traveling path hindering one another as little as possible, it is provided according to the invention that, when the destination call is allocated to one of the cars which can be made to travel along a common traveling path, the portion of the traveling path required by the allocated car to serve the destination call can be assigned to this car and that this portion of the traveling path is not accessible during the time of the assignment for the other cars which can be made to travel along the common traveling path. Such a configuration of the elevator installation makes it possible to assign a certain portion of the traveling path shared by a number of cars for a certain time, in dependence on the destination calls entered, to one of the cars which share the traveling path, so that this portion of the traveling path can be used only by this one car, while it is not accessible for a certain time for the other cars which can be made to travel along the common traveling path. To make it possible for the cars using a common traveling path to have the greatest possible freedom of movement, it is provided in the case of a preferred embodiment of the elevator installation according to the invention that the portion of the traveling path assigned to one of the cars which can be made to travel along a common traveling path can be released floor by floor for the other cars when the destination call is served. If the car serving the destination call, which has been assigned a specific portion of the traveling path, leaves a floor, this floor can immediately be released again for the other cars, so that it is accessible to another car for serving a subsequent destination call. It is of advantage if the control device of the elevator installation comprises a number of control units, respectively having a group control function, which are respectively associated with a car and are connected to one another via a data transmission system, it being possible for the allocation assessment for the respectively associated car to be carried out by means of the control units. The electrical connection of the control units may take place in a wire-bound or else wireless manner. It is of particular advantage if the data transmission system is configured as a BUS system. Alternatively, separate connecting lines may be used, it also being possible for a connection via light guides to be provided. A wireless connection may take place, for example, by radio. In the case of a preferred embodiment of the elevator installation according to the invention, the control units which are associated with the cars which can be made to travel along a common traveling path are connected to one another via a separate data line. The control units have in each case a central calculating unit, and it has proven to be advantageous if the central calculating units of the control units are directly connected to one another via the separate data line. It is particularly advantageous if the separate data line has a higher data transmission rate than the data transmission system. This makes possible a particularly rapid coordination of the control units associated with the cars which can be made to travel along a common traveling path. The input units disposed on the floors to be served by the elevator installation are preferably connected to at least one control unit via a data line. The data line may be of a wire-bound or wireless form, in particular in the form of a BUS system. It is of particular advantage if the control device comprises a central group control unit associated at least with the cars which can be made to travel along a common traveling path, for carrying out the allocation assessment and for allocating a destination call to one of the cars. It is particularly advantageous in this respect if the control device has both control units that are respectively associated with a car and a central group control unit, it being possible for an allocation assessment and allocation of a destination call to be carried out optionally by the decentralized control units or by the central group control unit. To be able to give a response to a passenger after a destination call has been entered, it is advantageous if the input units respectively have an associated indicating unit, for indicating the, car serving the destination call entered or the shaft with the stop at which the car will arrive, and preferably also for indicating the expected time until the arrival or departure of the car. Consequently, after entering a destination call, the passenger receives the information as to which car or which shaft he is to use and how long the expected waiting time will be. The elevator installation according to the invention is preferably configured in such a way that it is possible for two cars to be made to travel up and down along a common traveling path in one shaft. Preferably, both these cars can travel to all the stops with the exception of the lowermost and uppermost stops. In the case of a particularly preferred embodiment, the elevator installation comprises at least two shafts, it being possible for at least two cars to be made to travel along a common traveling path in a first shaft and for a single car to be made to travel along a traveling path from the lowermost stop to the uppermost stop in a second shaft. Such a configuration has the advantage that a user can be transported directly from the lowermost stop to the uppermost stop via the second shaft without changing cars, while a particularly high transporting capacity can be achieved in the first shaft for journeys in the region between the lowermost and the uppermost stops. The following description of a preferred embodiment of the invention serves for further explanation in conjunction with the drawing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic representation of an elevator installation according to the invention; and FIG. 2 shows a flow diagram of the method used according to the invention for controlling the elevator installation. DETAILED DESCRIPTION OF THE INVENTION Schematically represented in FIG. 1 is an elevator installation, which is provided overall with the reference numeral 10 and has a first shaft 12 and a second shaft 14 , in each of which two guide rails 16 , 17 and 18 , 19 are respectively held. The two guide rails 16 , 17 of the first shaft form a common traveling path for an upper car 21 and a lower car 22 , which can be made to travel up and down along the guide rails 16 and 17 . The upper car 21 is coupled to a counterweight 25 via a suspension rope 24 , and the lower car 22 is coupled to a counterweight 28 via a suspension rope 27 . Each of the two cars 21 and 22 has an associated separate drive in the form of an electric drive motor 30 and 32 , respectively, and in each case a separate brake 34 and 36 , respectively. The drive motors 30 , 32 in each case act on a traction sheave 38 and 40 , respectively, over which the suspension ropes 24 and 27 are led. The control of the cars 21 and 22 respectively takes place by means of a separate control unit 42 and 44 , which have a group control element 46 and 47 and a central computing unit 48 and 49 , respectively. The latter are connected directly to one another via a data line 50 configured in the form of a BUS system. The control units 42 and 44 are in electrical connection via control lines with the respectively associated drive motor 30 and 32 and also with the associated brake 34 and 36 , so that the cars 21 and 22 can be made to travel up and down in the usual way within the first elevator shaft 12 for the transportation of persons and/or loads. The second shaft 14 receives a single car 52 , which can be made to travel along the guide rails 18 and 19 from a lowermost stop to an uppermost stop and is coupled to a counterweight 56 via a suspension rope 54 , the suspension rope 54 being led over a traction sheave 58 , which is coupled to a drive associated with the car 52 in the form of an electric drive motor 60 . The car 52 has an associated separate brake 62 , which in a way similar to the drive motor 60 is in electrical connection via a control line with a control unit 64 associated with the car 52 . The control unit 54 comprises a group control element 66 and a central computing unit 67 . In addition to the control units 42 , 44 , 64 respectively associated with a car 21 , 22 and 52 , the elevator installation 10 may comprise a higher-level group control unit 70 with a connection element 71 , with the aid of which the group control unit 70 can be connected to a data transmission system 73 which is configured as a BUS system and via which all the control units 42 , 44 , 64 of the elevator installation 10 are connected to one another. The group control unit 70 forms in combination with the control units 42 , 44 and 64 a control device, provided overall with the reference numeral 75 in FIG. 1 , and can be used as an alternative to the control units 42 , 44 , 64 for controlling the elevator installation 10 . An input element with an integrated indicating element in the form of a touch-sensitive screen 77 is disposed on each floor which can be served by the elevator installation 10 . Furthermore, an indicating device 80 is located on each floor in the region of the shaft 12 and 14 . All the screens 77 and indicating devices 80 are connected to the control device 75 via an electrical connecting line 82 likewise configured as a BUS system. In the exemplary embodiment represented, the connecting line 82 is connected to the control unit 42 , which is in electrical connection via the data transmission system 73 with the remaining control units 44 and 64 and also the group control unit 70 that can alternatively be used. By means of the touch-sensitive screens 77 , a passenger can enter a destination call with a desired travel destination into the control device 75 , which then performs an allocation assessment and allocates one of the cars 21 , 22 , 52 to the destination call to answer it. As a response to the input of the destination call, the passenger is provided on the touch-sensitive screen 77 with an indication of the car to be used, and the expected time until the arrival of the car may also be indicated. On the additional indicating device 80 , the passenger is informed of the destinations to which the cars next arriving at the floor are to travel. If one of the travel destinations indicated coincides with the travel destination desired by the passenger, there is no need for him to enter a destination call. The expected time until the arrival of the next cars may also be indicated on the indicating device 80 . The allocation of a car to an entered destination call is explained in more detail below with reference to FIG. 2 . An entered destination call is transmitted via the electrical connecting line 82 to the control unit 42 of the control device 75 . The control unit 42 passes on the destination call via the data transmission system 73 to the remaining control units 44 and 64 of the elevator installation. Each control unit 42 , 44 and 64 was allocated a number when the elevator installation 10 was installed, and the entered destination call is stored by all the control units 42 , 44 and 64 respectively in a memory element which is known per se, and therefore not represented in the drawing, until the control unit with the smallest allocated number, for example the control unit 42 , transmits the signal for assessing the entered destination call to all the control units via the data transmission system 73 . In the method step 101 illustrated in FIG. 2 , an allocation assessment of the entered destination call is then performed by all the control units 42 , 44 and 64 for the respectively associated car 21 , 22 and 52 , on the basis of a prescribed assessment algorithm in dependence on the operating data and operating states of the respective car 21 , 22 and 52 , in order to ascertain the optimum car for serving the destination call with regard to the highest possible transporting capacity. After the allocation assessment has been performed, it is checked in a method step 102 by the control units 42 and 44 , which each have an associated car 21 and 22 respectively sharing the common traveling path 16 , 17 with a further car 22 or 21 , whether the portion of the traveling path required for serving the current destination call, that is to say the portion of the traveling path which, beginning from the current position of the respective car, extends via the starting point of the desired travel to the entered travel destination, overlaps at least partly a portion of the traveling path which has already been assigned to the respective car 21 or 22 in conjunction with a destination call entered earlier but not yet served to completion, that is to say has been “reserved” for this car. If one of the two control units 42 , 44 establishes that the portion of the traveling path required for serving the current destination call overlaps a portion of the traveling path already assigned to the respective car, the respective control unit 42 or 44 transmits in the method step 103 the result of the allocation assessment carried out via the data transmission system 73 to the remaining control units of the elevator installation 10 . If the check in the method step 102 reveals that the portion of the traveling path required for serving the current destination call does not overlap a portion of the traveling path already assigned to the respective car on the basis of an earlier destination call, it is checked in a method step 104 by the control units 42 and 44 whether the portion of the traveling path required for serving the current destination call overlaps at least partly a portion of the traveling path for which at least a provisional assignment exists for the other of the two cars 21 , 22 which can be made to travel along a common traveling path 16 , 17 , that is to say it is checked whether the portion of the traveling path required by the respective car 21 or 22 to serve the current destination call is completely free. If the required portion of the traveling path is not free for the respective car 21 or 22 , that is to say there is a provisional or definitive assignment for the other car 22 or 21 , respectively, the control unit 42 or 44 associated with this car sets the assessment to “cannot be served” in the method step 105 and transmits the information that the current destination call cannot be served by the respective car 21 or 22 via the data transmission system 73 to all the control units of the elevator installation 10 in the method step 103 . If the check in the method step 104 reveals that the portion of the traveling path required for serving the current destination call is free for the respective car 21 or 22 , in the method step 106 the respective control unit 42 or 44 transmits via the direct data transmission line 50 to the other control unit of the cars 21 , 22 which can be made to travel along the common traveling path 16 , 17 a signal according to which the respectively required portion of the traveling path is provisionally assigned to the respective car 21 or 22 . Subsequently, in the method step 107 it is checked by the control units 42 and 44 which of the two cars 21 and 22 has the better allocation assessment. For this purpose, the control units 42 and 44 transmit to one another the result of their allocation assessment via the data line 50 together with the provisional assignment of the portion of the traveling path, and respectively compare the results. The data transmission line 50 has for this purpose a data transmission rate which is higher than the data transmission rate of the data transmission system 73 . As an alternative, transmission via the normal data transmission system 73 may of course be chosen instead of the transmission via an additional data line 50 . The control unit 42 or 44 that is associated with the car with the better allocation assessment then transmits in the method step 103 the result of its own allocation assessment via the data transmission system 73 to the other control units of the elevator installation 10 , while the control unit 42 or 44 with the associated car 21 or 22 that has the poorer allocation assessment sets the assessment to “cannot be served” in a way corresponding to the method step 105 , and this is then transmitted via the data transmission system 73 in the method step 103 . In addition to one of the two control units 42 and 44 , that is the control unit which already has a “reservation” for its car or has the better allocation assessment for its car, in the method step 103 the control unit 64 associated with the car 52 also transmits the result of its allocation assessment via the data transmission system 73 . Consequently, after the method step 103 , all the control units 42 , 44 and 64 of the elevator installation 10 have the results of all the allocation assessments to be considered, so that subsequently a comparison of the allocation assessments and allocation of the current destination call can be performed by all the control units 42 , 44 and 64 . The control unit which receives the best allocation assessment for its car allocates the current destination call to itself and sends a corresponding allocation reply to the control unit 42 , which has read in the destination call, and this control unit 42 then sends the allocation reply via the connecting line 82 to the touch-sensitive screen 77 , on which the destination call was entered. On the screen 77 , it is then indicated to the passenger which car 21 , 22 or 52 or which shaft 12 or 14 he is to use and, if appropriate, how long it is expected to be before the desired car 21 , 22 or 52 will arrive at the passenger's floor. In the method step 108 , the two control units 42 , 44 then check whether the allocation of the current destination call was made to the respective car 21 or 22 . If this question is answered in the affirmative, in the method step 109 the corresponding control unit 42 or 44 transmits a definitive allocation signal via the direct data transmission line 50 to the other control unit with the car which is sharing the shaft 12 with its own car, with regard to the portion of the traveling path required for serving the destination call. Consequently, the portion of the traveling path required for serving the current destination call is definitively assigned to the car 21 or 22 , that is to say that in the method step 109 a definitive “reservation” is made of the portion of the traveling path required for serving the current destination call if one of the two cars 21 and 22 has the best allocation assessment. The control unit 42 or 44 that establishes in the method step 108 that the destination call was not allocated to the respective car 21 or 22 sends in the method step 110 via the direct data transmission line 50 to the other control unit a signal according to which the provisional assignment of the respectively required portion of the traveling path which was performed in the method step 106 is cancelled again. After carrying out the method steps 101 to 110 , it is consequently clarified which of the cars 21 , 22 and 52 of the elevator installation 10 is allocated a current destination call and whether in the case of an allocation to one of the cars 21 and 22 which can be made to travel along a common traveling path 16 , 17 an assignment of the portion of the traveling path required for serving the destination call has been made, with the effect that this portion of the traveling path is not available to the other car 21 or 22 respectively when it is serving a subsequent destination call.	The invention relates to a method for controlling an elevator installation with at least one shaft and a number of cars, it being possible to make at least two cars travel separately up and down along a common traveling path and a passenger being able to enter a destination call by means of an input unit disposed outside the shaft and the destination call being allocated to a car in dependence on an allocation assessment. To develop the method in such a way that the transporting capacity can be increased, with the cars which can be made to travel along a common traveling path hindering one another as little as possible, it is proposed according to the invention that, in the case of allocation of the destination call to one of the cars which can be made to travel along the common traveling path, the portion of the traveling path required for serving the destination call is assigned to this car and blocked for the time of the assignment for the other cars. Furthermore, an elevator installation for carrying out the method is proposed.	1
CROSS-REFERENCE TO RELATED APPLICATIONS The disclosure of Japanese Patent Application No. 2008-149200 filed on Jun. 6, 2008 including the specification, drawings and abstract is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION The present invention relates to an integrated circuit including an input protection circuit cell. FIG. 1 shows an input protection circuit cell 70 and a power supply cell 71 according to a conventional technology. To ensure ESD robustness, the input protection circuit cell 70 according to a conventional technology uses diodes 1 and 2 . The diodes each have a capacitance of several picofarads and are reversely coupled between a power supply voltage (VDD) and a signal input line and between the signal input line and a ground (GND). A series resistor 40 is serially coupled to the signal input line. In a power supply cell 51 , as shown in FIG. 1 , an input circuit 43 and a clamp circuit 4 are parallel coupled between VDD and GND. FIG. 2 shows in more detail the inside of the input circuit 43 and the clamp circuit 4 according to the conventional technology. A diode 44 is coupled between input and output sides of the input circuit 43 . The clamp circuit 4 includes a resistor 11 and a capacitor 12 that are serially coupled between VDD and GND. The clamp circuit 4 also includes an NMOS transistor 10 that uses the source terminal for the power supply voltage and the drain terminal for the ground. The clamp circuit 4 further includes an inverter 13 that has an input section coupled to a node between the resistor 11 and the capacitor 12 and an output section coupled to the gate terminal of the NMOS transistor 10 . FIG. 3 shows an example layout of the input protection circuit cell 70 and the power supply cell 71 . FIG. 4 shows a chip layout of an integrated circuit 80 mounted with an input protection circuit cell and a power supply cell according to a conventional technology. As shown in FIG. 4 , the layout is configured to include input protection circuit cells 50 and 51 and power supply cells 26 and 29 . The input protection circuit cells 50 and 51 each are equivalent to the input protection circuit cell 70 . The power supply cells 26 and 29 each are equivalent to the power supply cell 71 . The power supply cells 26 and 29 include clamp circuits 26 a and 29 a . In the overall chip configuration, as shown in FIG. 4 , the input protection circuit cells 50 and 51 are located adjacently to an RF input pad. The power supply cells 26 and 29 including the clamp circuit 4 are located adjacent to a VDD pad 20 or a GND pad 25 . Patent Documents 1 and 2 describe the methods of decreasing parasitic capacitance in an ESD protection circuit. Patent Document 1: Japanese Unexamined Patent Publication No. 2007-311813 Patent Document 2: Japanese Unexamined Patent Publication No. SUMMARY OF THE INVENTION There has been a problem that a high-frequency signal supplied to an RF input pad attenuates due to a large input capacitance from the diodes 1 and 2 of several picofarads and parasitic resistance components from the series resistor 40 . The following describes why the diode capacitance increases. The input protection circuit cells 50 and 51 are routed to the power supply cells 26 and 29 via wiring metal such as discharge paths 100 and 101 in FIG. 4 . The discharge path 100 (discharge path 9 in FIG. 1 ) provides the shortest distance from the pulse input to the GND. The discharge path 101 includes the power supply cell 26 adjacent to the VDD pad. A clamp circuit 26 a of the power supply cell 26 is distant from the RF input pad and the GND pad. The parasitic resistance 41 in FIG. 1 cannot ensure a low impedance, making the ESD robustness insufficient. To solve this problem, the diode needs to decrease the operating voltage when an ESD is applied. For this reason, the diode requires a larger size than is used for maintaining the specified ESD robustness. The diode capacitance increases accordingly. For example, let us consider that a human body model electrostatic discharge (HBM/ESD) test is conducted on the circuit in FIG. 1 to apply a positive surge voltage of 2000 V to the RF input pad with reference to the GND. In this case, a peak current approximates to 1.33 A. Let us suppose that the clamp circuit 4 operates on Vc (V) and that the diode 1 has a size large enough to satisfy an HBM withstand voltage of 2000 V or higher and operates on Vd (V). In this case, the voltage drops approximately by 1.33 Rp (V) when the parasitic resistance 41 is Rp (O). In total, the RF input pad is supplied with (Vc+Vd+1.33 Rp) voltages. A circuit to be protected is assumed to be supplied with a degradation start voltage Vic set to 11 V. The degradation start voltage Vic is expressed as follows: Vic (=11 V)<Vc+Vd+1.33 Rp (=5+2.3+4=11.3 V), where Vc is set to 5 V, Vd to 2.3 V, and Rp to 3 O. The circuit to be protected is supplied with a voltage higher than or equal to the degradation start voltage. It is impossible to satisfy the condition of the HBM withstand voltage of 2000 V or higher. The diode 1 requires increasing its area so as to keep the operating voltage Vd smaller than or equal to (Vic−Vc−1.33 Rp)=11−5−4=2 V even though the diode 1 itself has the size large enough to ensure the HBM withstand voltage of 2000 V or higher. Since the discharge path causes a high resistance, the series resistor 40 is also needed to protect the internal circuit. The methods described in Patent Documents 1 and 2 reduce parasitic capacitance in the ESD protection circuit. However, the methods do not decrease the resistance on the discharge path and do not solve the problem due to the high resistance. The present invention has been made in consideration of the foregoing. It is therefore an object of the present invention to decrease parasitic resistance between an input protection circuit cell and a clamp circuit in an integrated circuit, restrain a diode size from becoming larger than ESD robustness of a diode itself for compensating a decrease in the ESD robustness, and prevent high-frequency signal power from attenuating due to input capacitance components from a diode in an input protection circuit and parasitic resistance components of a series resistor. An integrated circuit according to an embodiment of the invention includes: a signal pin; an internal circuit including a high-frequency circuit; and an input protection circuit cell that is placed between the signal pin and the internal circuit and performs a protection operation when a signal at the signal pin is applied to the high-frequency circuit. The input protection circuit cell includes: an input terminal coupled to the signal pin; an output terminal that is coupled to the high-frequency circuit and to the input terminal via a coupling node; a first diode that is provided between the coupling node and a high-voltage power supply and makes an electric current flow from the coupling node to the high-voltage power supply; and a second diode that is provided between the coupling node and a low-voltage power supply and makes an electric current flow from the low-voltage power supply to the coupling node. The input protection circuit cell further includes: a clamp circuit that is coupled parallel to the first and second diodes between the high-voltage power supply and the low-voltage power supply. The integrated circuit according to the embodiment of the invention configures the clamp circuit in the input protection circuit cell. This makes it possible to provide more discharge paths for an ESD pulse current than conventional arts and reduce the impedance. The reduction in the impedance for the discharge path can minimize the size of the diode for the input protection circuit so that the ESD robustness can be ensured. It is possible to reduce a loss in the high-frequency signal while ensuring the ESD robustness. The reduction in the impedance for the discharge path can eliminate a serially coupled resistor element and reduce a loss in the high-frequency signal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a circuit including an input protection circuit cell and a power supply cell according to a conventional technology; FIG. 2 shows a circuit including an input protection circuit cell and a power supply cell according to a conventional technology; FIG. 3 shows a layout including an input protection circuit cell and a power supply cell according to a conventional technology; FIG. 4 shows a chip layout according to a conventional technology; FIG. 5 shows a circuit of an input protection circuit cell according to the invention; FIG. 6 shows a circuit of the input protection circuit cell according to the invention; FIG. 7 shows a layout of the input protection circuit cell according to the invention; FIG. 8 shows a circuit of the input protection circuit cell according to the invention; FIG. 9 shows a layout of the input protection circuit cell according to the invention; FIG. 10 shows a chip layout according to the invention; and FIG. 11 shows an enlarged part of the chip layout according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes the invention with reference to the accompanying drawings showing embodiments. <Configuration> FIG. 5 shows a circuit diagram of the input protection circuit cell according to an embodiment of the invention. An input protection circuit cell 70 is located between a signal pin of a mounted integrated circuit and an internal circuit including a high-frequency circuit. The input protection circuit cell 70 includes an input terminal 7 and an output terminal 8 . The input terminal 7 is coupled to the signal pin. The output terminal 8 is coupled to the high-frequency circuit as well as the input terminal 7 and a node (coupling node) 60 . A first diode 1 is provided between the node 60 and a high-voltage power supply (VDD) 5 and supplies an electric current from the node 60 to the VDD 5 . A second diode 2 is provided between the node 60 and a low-voltage power supply (GND) 6 and supplies an electric current from the GND 6 to the node 60 . Further, a clamp circuit 4 is coupled between the VDD 5 and the GND 6 parallel to the diodes 1 and 2 . Reference numeral 3 denotes parasitic resistance along the discharge path 9 . FIG. 6 shows a circuit diagram of the input protection circuit cell 70 including the clamp circuit 4 whose inside is revealed. The clamp circuit 4 includes an NMOS transistor 10 having a source terminal coupled to the VDD 5 and gate and drain terminals coupled to the GND 6 . FIG. 7 illustrates a layout example of the input protection circuit cell 70 shown in FIG. 6 . The input protection circuit cell 70 includes a VDD ring 30 (first wiring) and a GND ring 5 b (second wiring). The VDD ring 30 supplies VDD. The GND ring 5 b is placed parallel to the VDD ring 30 and supplies GND. The input protection circuit cell 70 further includes diodes 1 and 2 . The diode 1 is placed between the VDD ring 30 and GND ring 5 b near the VDD ring 30 . The diode 2 is placed between the VDD ring 30 and GND ring 5 b near the GND ring 5 b . The input protection circuit cell 70 furthermore includes the NMOS transistor 10 , an output terminal 8 a , and an input terminal 7 a . The NMOS transistor 10 is placed outside the GND ring 5 b . The output terminal 8 a is placed outside the VDD ring 30 . The input terminal 7 a is placed outside the NMOS transistor 10 . Compared to a conventional technology, the embodiment reduces the size of the diodes 1 and 2 by reducing the impedance of the discharge path to be described later. Since the NMOS transistor 10 is used as a clamp circuit, it is possible to reduce the layout area in comparison with the clamp circuit 4 in FIG. 2 according to the conventional technology. The clamp circuit 4 can be contained in the input protection circuit cell 70 . The embodiment eliminates the series resistor 40 that is used for the conventional technology. FIG. 8 shows a circuit diagram of the input protection circuit cell 70 including the clamp circuit 4 according to another mode. The clamp circuit 4 includes the resistor 11 and the capacitor 12 . The resistor 11 is coupled between the VDD 5 and a node 61 (first node). The capacitor 12 is coupled between the node 61 and the GND 6 . The clamp circuit 4 also includes the inverter 13 and the NMOS transistor 10 . The inverter 13 is coupled between the node 61 and a node 62 (second node). The inverter has an input side corresponding to the node 61 and an output side corresponding to the node 62 . The NMOS transistor 10 has a gate terminal coupled to the node 62 , a source terminal coupled to the VDD 5 , and a drain terminal coupled to the GND 6 . FIG. 9 shows a layout example of the input protection circuit cell 70 shown in FIG. 8 . The input protection circuit cell 70 includes: the VDD ring 30 that supplies VDD; a GND ring 31 placed parallel to the VDD ring 3 and supplies GND; the diode 1 (first diode) placed under the VDD ring 30 ; and the diode 2 (second diode) placed between the VDD ring 30 and the GND ring 31 beside the diode 1 . The input protection circuit cell 70 further includes: the resistor 11 placed between the VDD ring 30 and the GND ring 31 beside the diode 2 ; the capacitor 12 placed between the VDD ring 30 and the GND ring 31 beside the resistor 11 ; the inverter 13 placed under the GND ring 31 ; the NMOS transistor 10 placed outside the GND ring 31 ; an output terminal 8 a placed outside the VDD ring 30 ; and an input terminal 7 a placed outside the NMOS transistor 10 . Compared to a conventional technology, the embodiment reduces the size of the diodes 1 and 2 by reducing the impedance of the discharge path to be described later. The input protection circuit cell 70 in FIG. 8 uses a clamp circuit equivalent to the clamp circuit 4 in FIG. 2 according to the conventional technology. The circuit design is changed to halve the capacitor 12 and double the resistor 11 . The clamp circuit 4 can be contained in the input protection circuit cell 70 by matching the CR time constant and reducing the layout area. The embodiment eliminates the series resistor 40 that is used for the conventional technology. FIG. 10 shows a chip layout of the integrated circuit 80 according to the embodiment. The integrated circuit 80 contains a high-frequency circuit 81 and a low-frequency circuit 82 . Near the high-frequency circuit 81 , there are provided the VDD pad 20 , a control signal pad 21 , an RF input pad 22 , an RF input pad 23 , a control signal pad 24 , and the GND pad 25 . The VDD pad 20 and the GND pad 25 contain power supply cells 26 and 29 (equivalent to the power supply cell 71 in FIGS. 1 and 2 ) that further contain clamp circuits 26 a and 29 a . The RF input pads 22 and 23 contain input protection circuit cells 27 and 28 (equivalent to the input protection circuit cell 70 in FIGS. 1 and 2 ). The input protection circuit cells 27 and 28 are placed between the RF input pads 22 and 23 coupled to signal pins of the integrated circuit 80 and the internal circuit containing the high-frequency circuit 81 . The input terminal 7 in FIG. 5 is coupled to the RF input pads 22 and 23 . The output terminal 8 is coupled to the high-frequency circuit 81 . The VDD ring 30 and the GND ring 31 are wired so as to be common to the entire chip. FIG. 11 shows an enlarged view around the cells in FIG. 10 . <Operations> The following describes operations. First, clamp circuit operations will be described. The clamp circuit 4 in FIGS. 6 and 7 uses characteristics of an NMOS transistor that the NMOS transistor causes a parasitic bipolar operation outside a normal operation range. During a normal operation, the NMOS transistor 10 hardly makes an electric current flow because the drain is supplied with a specified voltage. When a surge is applied, the drain is supplied with a large voltage. The NMOS transistor 10 causes a parasitic bipolar operation to makes an electric current flow through the discharge path 9 . During a normal operation, the clamp circuit in FIGS. 8 and 9 allows the inverter 13 to be supplied with an H level voltage and output an L level voltage. The NMOS transistor 10 turns off. Immediately after a surge is applied, the source of a PMOS transistor (not shown) for the inverter 13 is supplied with the applied surge voltage. The gate of the PMOS transistor for the inverter 13 maintains a voltage before the surge is applied. A voltage difference between the source and the gate turns on the PMOS transistor for the inverter 13 . Turning on the PMOS transistor increases a gate potential of the NMOS transistor 10 to turn on the NMOS transistor 10 . The current caused by the applied surge flows through the discharge path 9 to the GND. A delay circuit including the resistor 11 and the capacitor 12 propagates the applied surge voltage. The PMOS transistor for the inverter 13 turns off. The NMOS transistor 10 turns off to terminate the discharge. The clamp circuit 4 is not limited to the configurations as shown in FIGS. 6 , 7 , 8 , and 9 . The clamp circuit 4 may be configured not to apply the current to the discharge path 9 during a normal operation and to apply the current to the discharge path 9 when a surge is applied. FIG. 11 shows the discharge path in the integrated circuit 80 . The conventional technology uses only the discharge paths 100 and 101 in consideration for application of a surge to the RF input pad 22 . According to the embodiment, the input protection circuit cells 27 and 28 contain the clamp circuits having discharge paths 200 and 201 shorter than the discharge path 101 . Similarly to the conventional technology, let us examine a case where the human body model electrostatic discharge (HBM/ESD) test applies a positive surge of 2000 V from the RF input pad to the input terminal 7 with reference to the GND. The increased paths decrease the parasitic resistance for the discharge path in the entire chip in comparison with the conventional technology that uses the clamp circuits only in the power supply cell. It is assumed that the parasitic resistance becomes 0.3 O while the conventional technology indicates 3 O. The peak current approximates to 1.33 A. The clamp circuit 4 is assumed to operate on Vc (V). The diode itself is assumed to be so sized as to satisfy the HBM withstand voltage of 2000 V or higher and is assumed to operate on Vd (V). The voltage drops by 1.33 Rpp (V) when the parasitic resistance 3 is assumed to be Rpp (O). In total, the RF input pad is supplied with (Vc+Vd+1.33 Rpp) (V). Let us assume that Vic is set to 11 V as a degradation start voltage for the circuit to be protected. The voltage is expressed as: Vic (=11V)>Vc+Vd+0.133 Rp (=5+2.3+0.4=7.7 V), where Vc=5 V, Vd=2.3 V, and Rpp=0.3 O. These networks do not reach the degradation start voltage for the circuit to be protected and are capable of discharging an ESD pulse current caused by the HBM test. <Effects> The discharge path can be increased as shown in FIG. 11 because the clamp circuit 4 is contained in the input protection circuit cell 70 . The discharge path 200 can ensure the shortest distance from the GND because the clamp circuit is always available adjacently to the input pad. It is possible to use the discharge path 201 provided by the clamp circuit in the other input protection circuit. The conventional discharge paths 100 and 101 are also available. That is, it is possible to increase the discharge paths for an ESD pulse current, maintain a low impedance, and ensure the number of clamp circuits needed in the chip. Since the discharge path ensures a low impedance, it is possible to minimize the size of the diodes 1 and 2 in the input protection circuit cell 70 so that the ESD robustness is ensured. It is possible to reduce a loss in the high-frequency signal while the ESD robustness is ensured. Since the discharge path ensures a low impedance, it is possible to eliminate the serially coupled series resistor 4 and reduce a loss in the high-frequency signal. The embodiment of the invention can be applied to RFICs for wireless LAN and the other high-frequency integrated circuits in general.	An integrated circuit aims to decrease a parasitic resistance between an input protection circuit cell and a power supply cell including a clamp circuit, restrain a size of a diode from increasing beyond ESD robustness of the diode itself in order to compensate for a decrease in the ESD robustness, and prevent high-frequency signal power from decreasing due to a large capacitance component from a diode in an input protection circuit and a parasitic resistance component from a series resistor. The input protection circuit cell includes: an input terminal coupled to a signal pin; an output terminal coupled to not only a high-frequency circuit but also the input terminal and a node; a diode that is provided between the node and VDD and makes an electric current flow from the node to VDD; another diode that is provided between the node and GND and makes an electric current flow from GND to the node; and a clamp circuit coupled between VDD and GND parallel to the diodes.	7
BACKGROUND OF THE INVENTION [0001] The invention relates to suspended ceiling systems and, in particular, to an improved grid tee. PRIOR ART [0002] Suspended ceilings, extensively used in commercial buildings, typically employ a rectangular grid system that supports lay-in ceiling panels or tiles. The grid is made up of regularly spaced runners intersecting at right angles. The runners are ordinarily in the form of inverted tees. The tees are normally suspended by wires and the ceiling panels or tiles rest on the flanges of the tees. [0003] The suspended ceiling products industry has refined the design and manufacture of grid tees to a high degree. The continuous efforts for improvement have contributed to the high acceptance of these ceiling systems in the construction industry. Challenges have remained in creating improvements in the performance and in reducing the cost of the grid systems. SUMMARY OF THE INVENTION [0004] The invention provides an improved grid tee for suspended ceilings that, compared to prior art constructions can facilitate installation of lay-in tiles, can be produced with less material cost and can obtain greater strength and rigidity. The invention, in one design, utilizes a single strip of sheet metal folded on itself in such a manner that the bending and torsional stiffness as well as suspension wire breakout can be increased even while metal content can be decreased. The folded cross-section of the single strip design advantageously employs the visible face of the tee as a primary structural element so that the face serves to increase rigidity. Employing the face material as a structural element is particularly advantageous because the face material is at a location where it can be of maximum benefit as it contributes to the polar moment of inertia. The longitudinal edges of the strip are folded into mutual contact and are locked together both laterally and longitudinally, thereby significantly increasing the torsional stiffness of the tee. [0005] Multiple layers of sheet material at the top of the inverted tee section permit suspension wires to be threaded through this area without the risk of low breakout strength. The multiple layer top edge surmounts a laterally extending reinforcing bulb. This geometry avoids the necessity of wrapping the bulb itself with a loop of suspension wire. As a result, the suspension wire loop can be smaller than the width of the bulb. Consequently, the ceiling tiles can be easily and quickly installed or removed without damage or difficulty from interference with what otherwise would be an oversize wire loop of suspension wire. As disclosed, the inventive feature of a narrow top wire receiving stem portion can be applied to other tee constructions. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a perspective view of a grid tee constructed in accordance with the invention; [0007] FIG. 2 is a cross-sectional view of the grid tee on an enlarged scale; [0008] FIG. 3 is an enlarged elevational view of a part of an upper portion of the grid tee; [0009] FIG. 4 is a cross-sectional view of the upper portion of the grid tee taken on the plane 4 - 4 indicated in FIG. 3 showing one manner of locking the grid tee layers together; [0010] FIG. 5 is a view similar to FIG. 4 with another example of a manner of locking the layers of the grid tee upper portion together; [0011] FIG. 6 is a perspective view of a section of a grid tee in accordance with another embodiment of the invention; [0012] FIG. 7 is a cross-sectional view of the grid tee taken in the plane 7 - 7 indicated in FIG. 6 ; [0013] FIG. 8 is a cross-sectional view of a modified grid tee; [0014] FIG. 9 is a cross-sectional view of another modified grid tee; [0015] FIG. 10 is a cross-sectional view of a further modified grid tee; and [0016] FIG. 11 is a cross-sectional view of still another modified grid tee. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] A grid tee 10 is preferably formed of a sheet metal strip which can be galvanized or otherwise treated to resist corrosion. The tee 10 is made, preferably by roll-forming techniques known to those skilled in the art, into the cross section illustrated, for example, in FIG. 2 . A center section 12 of the strip 11 is preferably painted before the strip is formed into the tee cross-section. The painted center section 12 forms a visible face 13 . The sheet metal strip 11 is folded back on itself at opposed edges of the face 13 to form a double layer flange 14 extending laterally on opposite sides of a central web or stem 16 . Inner layers 17 of the flange 14 extend from the laterally outward extremities of the flange to a central imaginary plane 18 and preferably abut the outer layer or center section 12 substantially along their full widths. The inner layers 17 of the flange 14 intersect at the imaginary plane 18 where the sheet metal strip is bent at right angles to form the web 16 as double layers 19 , 20 . At a distance above the flange 14 , preferably greater than about half the total height of the web 16 , the web layers 19 , 20 are each formed with a channel 21 open on an inside face. The channels 21 , ideally, are mirror images of one another symmetrically disposed about the central imaginary plane 18 and cooperating to form a hollow reinforcing bulb 22 . The illustrated bulb 22 is generally circular in cross-section but can have other shapes such as rectangular. [0018] At an upper portion 24 of the web 16 above the bulb 22 , the two web layers 19 , 20 abut at or adjacent the imaginary central plane 18 for a vertical distance that, in the illustrated case, is the about the same as the vertical extent of the bulb 22 . The layer 20 of one side of the web 16 is somewhat wider than the other side enabling an excess width part 26 to be folded over the other layer 19 . As a result, the upper edge of the web 16 comprises three layers of sheet stock. The layers 19 , 20 and 26 at this upper edge portion 24 of the web 16 are fixed relative to each other by lanced tabs 31 cut through the material of these layers with suitable punches. Each lanced tab 31 can be distorted to foreshorten it and then be set back partially into the plane of the web 16 but out of registration with its original layer so that it is locked against the edge of an adjacent layer thus locking such adjacent layers from moving in the longitudinal direction of the tee relative to each other as well as in any other direction relative to one another. In the illustrated example, the lanced tabs 31 are in groups of four, a pair on the right is displaced above the plane of the drawing of FIG. 3 as shown in FIG. 4 . The pair at the left are similarly spaced below the plane of the drawing. [0019] The lower part of the web 16 is formed with longitudinally spaced slots 36 aligned through both layers 19 , 20 for receiving end connectors of cross tees as is conventional. Holes or apertures 37 are punched or otherwise formed in the upper part 24 of the web 16 spaced along the length of the tee 10 . These holes 37 are provided for suspending the tee 10 and ultimately the ceiling tiles supported on the tees, with wires such as that shown in FIG. 2 . The disclosed arrangement wherein the suspension wires 38 are assembled through flat, vertical abutting layers 19 , 20 , 26 of the web 16 above the reinforcing or stiffening bulb 22 , permits the profile or spread of a wire loop 39 around the upper web portion 24 to be relatively narrow and have less width in a plane transverse to the longitudinal direction of the tee than the width of the bulb 22 . This is a significant advantage when installing and removing ceiling tiles since interference between the wire loops 39 and tile is effectively eliminated and, the risk of damage to the tile is effectively avoided. This feature can reduce overall installation time and cost of a ceiling system. [0020] Various methods, besides the lanced tabs 31 , can be used to lock the sheet metal layers 19 , 20 and 26 at the upper region 24 of the web 16 together so that there is no longitudinal slippage of these layers relative to one another. FIG. 5 illustrates one alternative for locking these layers 19 , 20 and 26 together and is disclosed in greater detail in U.S. Pat. No. 6,041,564. A hole 40 is pierced through these layers 19 , 20 and 26 , and the material of one layer 19 is formed into an integral rivet or eyelet 42 . The hole 40 can be used for suspending the grid tee by threading the suspension wire 38 through it. U.S. Pat. Nos. 5,979,055 and 6,047,511, for example, show other methods of locking the stem layers together with material integral with the stem. Alternatively, the layers 19 , 20 and 26 of the upper region or portion 24 can be fixed against relative movement by other methods such as with separate fasteners, welding, and/or adhesives, for example. With the layers of the stem or web 16 fixed together, the torsional stiffness of the tee or grid member is increased from what would occur where the layers were free to slide relative to one another. [0021] FIGS. 6 and 7 illustrate a second embodiment of a grid tee 50 , constructed in accordance with the invention. The tee is formed of a single metal strip 51 preferably with its center region painted on one side to finish a face 52 of an exposed layer 53 . The strip is ideally galvanized or otherwise finished prior to finish painting to avoid corrosion. The strip 51 is preferably shaped by roll-forming techniques, and is folded back on itself to form opposite sections 54 of a lower flange 56 . Inner flange layers 57 ideally abut the face layer 53 along substantially their full width, which is short of half the width of the face layer. At interior edges of the inner flange layers 57 , the tee sheet material is bent up vertically to form respective sides 58 of a hollow bulb 59 forming a lower section of a web or stem 61 . At the top of the bulb 59 , layers of the sheet or strip 51 are turned towards a central imaginary plane 62 and at the central plane are then folded or bent upwardly so that sections 63 of the metal strip 51 form an upper region 65 of the web 61 . The web upper region layers 63 are fixed together by integral rivets or grommets 60 each formed from the material of one layer 63 displaced through a hole in the other layer and then upset or clinched to form a flange 64 on the outer side of the other layer. The upper region 65 of the web 61 can be constructed like the analogous region 24 of the tee 10 shown in FIG. 2 , if desired, thereby comprising three layers in this web region. A suspension wire 38 can be passed through a selected hole or aperture 66 of a rivet 60 and looped around a portion of the upper web section as shown in FIGS. 6 and 7 . As with the grid tee 10 , the upper portion 65 of the web 61 can have its layers locked together with other alternative or supplemental techniques such as staking, use of separate fasteners, welding and/or adhesives, for example. Along the length of the tee 50 at regularly spaced centers, such as every six inches the sides 58 of the hollow bulb 59 are locally deformed with oval or oblong depressions 71 of sufficient depth to cause the sheet material of each of the sides 58 to abut. The depressions 71 are of sufficient height to allow a vertical slot 72 to be formed in each of the layers of the sides 58 for the reception of end connectors of cross tees. The height and width of the depressions 71 is sufficient to receive an end connector and allow it to pass through the respective slot 72 . Less than all of the holes formed in the upper region of the web can be clinched in the manner of a grommet. [0022] The ends of the tees 10 and 50 can be provided with standard connectors; typically the ends of the tee 50 are flattened by pressing the walls or sides 58 together to accommodate a standard connector. [0023] FIGS. 8-11 illustrate additional alternative embodiments of tee constructions. In FIG. 8 , a sheet metal tee 75 formed in the manner described above has a flange 76 and a stem 77 including a hollow bulb portion 78 and an upper portion 79 formed of a single strip of metal stock. The strip is doubled on itself, as described above, in the flange and stem areas apart from the hollow bulb 78 . The upper stem area or portion 79 is sandwiched by a separately formed inverted U-shape metal channel 81 . The channel 81 can be roll formed from a sheet metal strip. The layers of the upper stem portion 79 and channel 81 are fixed together by any of the methods of the previously described tees. [0024] A tee 85 depicted in FIG. 9 is similar in construction to the tee 75 of FIG. 8 and has certain parts designated with the same numerals. The upper stem portion 79 has its layers reinforced by an intermediate strip 86 preferably of a suitable metal such as steel. As before, the abutting layers of the upper portion of the stem 79 and strip 86 are locked together by one of the techniques described above. [0025] FIG. 10 illustrates an extruded tee 90 having a flange 91 and stem 92 . The stem 91 includes a hollow bulb 93 . The tee 90 can be formed of aluminum or other suitable metal or plastic. [0026] FIG. 11 illustrates still another tee 95 formed, like earlier described tees of strips of roll formed metal sheet stock. The tee 95 comprises a main body strip 96 and a cap strip 97 . The main body strip 96 forms an upper or inner layer of a flange 98 and a stem 99 . The cap strip 97 forms the cover or outer face layer of the flange 98 and includes opposed in-turned hems 101 that lock the cap strip 97 on the main strip 96 and the adjacent areas of the stem 99 together. The stem 99 includes a hollow bulb 102 and an upper portion 103 . [0027] In each of the arrangements of FIGS. 8-11 , holes 106 can be spaced along the length of the tee in the upper stem portion and any associated structure. Suspension wires 38 can be looped through such holes 106 in the upper portion of the tee stem or web above a hollow bulb. This feature, as in the arrangements of FIGS. 1-7 , permits the wire loop 39 to be at least as small in width as the width of the respective bulb thereby avoiding interference with installation or removal of a ceiling tile. [0028] While the invention has been shown and described with respect to particular embodiments thereof, this is for the purpose of illustration rather than limitation, and other variations and modifications of the specific embodiments herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. For example, the upper edge region of the web can be formed with more than three layers of sheet metal by making additional folds. Accordingly, the patent is not to be limited in scope and effect to the specific embodiments herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.	In one embodiment, a roll-formed sheet metal tee for grid type suspended ceilings with the face of its flange integral with the stem and the layers of the stem fixed together for improved torsional strength. An upper region of the stem can have one or more of its layers folded to increase suspension wire breakout strength. A stiffening bulb is below suspension wire receiving holes so that a loop of the suspension wire through the tee has a narrow profile and thereby avoids interference with ceiling panels during their installation or removal. Other embodiments of a tee share the feature of a narrow, suspension wire receiving upper stem portion.	4
This is a continuation of Ser. No. 09/852,993 filed May 10, 2001 now U.S. Pat. No. 6,767,886. FIELD OF THE INVENTION This invention is directed to a composition that may be used to treat a substrate. More particularly, the invention is directed to a composition that improves the characteristics of a substrate, like a fabric. The characteristics of the substrate are improved as a direct result of the composition and substrate coming into contact, and the improvements may be realized without the need to employ a mechanical washer, dryer, or ironing device. BACKGROUND OF THE INVENTION It is desirable in busy households to minimize the amount of work required to treat substrates. Particularly, it is very desirable to minimize the amount of work required to reduce or even eliminate, for example, wrinkles in substrates such as clothing. This is especially true when a consumer has worn clothing for a brief period of time and plans to wear the clothing a second time before having it, washed, dried and/or ironed. Attempts to reduce wrinkles in clothing have been made, and especially with the introduction of durable permanent press treatments in the textile industry. Such treatments are known to employ polycarboxylic acids to strengthen the fibers of the textile, thereby rendering them less likely to wrinkle. Notwithstanding the above-described permanent press treatments, it is well settled that the effects of such treatments do not last long after the textiles (e.g., clothing) are subjected to a few washing cycles. A need exists to reduce wrinkles in substrates, like clothing, that may not be subjected to washing, drying and/or ironing, even if the substrates have been subjected to permanent press treatments. This invention, therefore, is directed to a composition that improves the characteristics of a substrate as a direct result of the substrate coming into contact with the composition. The characteristics which are improved by the composition described in this invention include the reduction of substrate wrinkles and/or the reduction of substrate shape distortion. ADDITIONAL INFORMATION Efforts have been disclosed for spraying surfaces. In U.S. Pat. No. 5,783,544, a spray composition for reducing malodor is described. Still other efforts have been disclosed for spraying surfaces. In U.S. Pat. No. 5,663,134, a spray composition with less than 1.0% by weight of monohydric alcohol is described, and the composition is used to reduce malodor impressions on inanimate surfaces. Even further, additional attempts have been made to spray surfaces. In U.S. Pat. No. 5,534,165, spray compositions with odor absorbing features are described. None of the references above disclose a composition that may be sprayed on to a substrate in order to reduce wrinkle formation and/or shape distortion of the substrate. As used herein, substrate is defined to mean a textile having the capacity to wrinkle, including curtains, table cloths, upholstery, and especially, clothing. Substrate enhancing agent is defined to mean a compound (including oligomers and polymers) that results in a reduction in wrinkle formation and/or shape distortion of a substrate. Such a substrate enhancing agent is also meant to include a compound that enhances the wrinkle reducing properties of conventional wrinkle reducing additives. SUMMARY OF THE INVENTION In a first embodiment, this invention is directed to a composition for improving substrate characteristics, the composition comprising: (i) from about 0.1 to about 20.0% by weight of a least one substrate enhancing agent selected from the group consisting of a polyhydric alcohol, a polyether, a monohydric alcohol and a mixture thereof; and (ii) greater than about 5.0% by weight water wherein the polyhydric alcohol is at least a C 4 polyhydric alcohol, the polyether comprises at least one alkylene chain of at least 4 carbons and the monohydric alcohol is at least a C 5 monohydric alcohol. In a second embodiment, this invention is directed to a method for reducing wrinkles and/or shape distortion of a substrate by using the composition described in the first embodiment of this invention. In a third embodiment, this invention is directed to an article of manufacture comprising the composition described in the first embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, may be best understood by reference to the following description taken in conjunction with the accompanying drawing FIGURE in which: The FIGURE illustrates a side view of a trigger sprayer which may be used to dispense the composition for improving substrate characteristics of this invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS There is no limitation with respect to the type of polyhydric alcohol used in this invention other than that the polyhydric alcohol has at least a C 4 carbon chain. Polyhydric alcohol, as used herein, is defined to mean a compound with more than one hydroxy group and no ether links within its backbone. An illustrative list of the polyhydric alcohols which may be used in this invention includes C 4 to C 18 alkane diols, like 1,4-butane diol, 1,5-pentane diol and 1,10-decane diol. Others include C 6 to C 18 cycloalkane diols like 1,4-cyclohexane diol. The polyhydric alcohols which may be used in this invention can be prepared, for example, by base-or-acid-catalyzed cleavage reactions of epoxides, or by the oxidation of alkenes. Such polyhydric alcohols are also made commercially available by suppliers like Aldrich Chemical. Regarding the polyethers which may be used in this invention, these compounds may be oligomers or polymers and have, in their respective backbones, at least one alkylene chain having at least 4 carbon atoms. An illustrative list of the polyethers (e.g., polyalkylene glycols) which may be used in this invention includes polybutylene glycol, polypentylene glycol, polyhexylene glycol, and any copolymers (including terpolymers) of the same. The polyethers used in this invention are typically made by conventional techniques which include the polymerization of alkylene oxides via a mechanism initiated by anions. Such polyethers are also made commercially available by suppliers like Dow Chemical, and typically have a weight average molecular weight (mw) from about 500 to about 20,000; and preferably, from about 1000 to about 10,000, including all ranges subsumed therein. The monohydric alcohols which may be used in this invention are limited only to the extent that they include alcohols having at least 5 carbon atoms in a linear chain. The preferred monohydric alcohols include those which have greater than about 7 carbon atoms. The most preferred monohydric alcohols include those which have greater than about 15 carbon atoms, like cetyl alcohol, octadecyl alcohol, and mixtures thereof (e.g., tallow alcohol). The monohydric alcohols that may be used in the present invention may be prepared by any conventional technique, such as those which react acid chlorides with organometallic compounds. The monohydric alcohols which may be used in this invention may also be purchased from suppliers like Sigma. There is no requirement for the substrate enhancing agent of this invention to be saturated, and therefore, such an agent may comprise sites of mono- or polyunsaturation. In an especially preferred embodiment, the substrate enhancing agent of this invention has a weight average molecular weight of greater than about 180 or a boiling point greater than about 216° C., or both. There is no limitation with respect to how the composition of the present invention is made as long as the desired components are mixed to produce a composition that may be applied to a substrate. For example, the substrate enhancing agent may be added to a mixing vessel along with water. The amount of water in the composition that may be used to treat a substrate is greater than 5.0%, and typically, from about 70.0% to about 99.9% by weight of the total weight of the composition. Most preferably, however, water makes up from about 75.0% to about 97.0% by weight of total weight of the composition, including all ranges subsumed therein. The mixing of desired components may occur at conventional mixing rates. The temperature and pressure during mixing may vary, as long as the desired composition for improving substrate characteristics may be made. Typically, however, the composition of this invention may be made by mixing under conditions of moderate shear, with temperature being from about 25° C. to about 85° C. and pressure being atmospheric. Optional additives which may be employed in the compositions of the present invention include low molecular weight alkanols (i.e., alcohols with a backbone of four (4) carbons or less). The low molecular weight alcohols which may be used in this invention may assist in improving the characteristics of the substrate being treated with the composition of this invention. Also, such low molecular weight alcohols can significantly decrease the drying time of the composition applied to the substrate, thereby enabling the consumer to, for example, use the substrate (e.g., clothing) shortly after being contacted with the composition. The amount of low molecular weight alcohols which may be used in this invention typically is from about 0.0% to about 10.0%, and preferably, from about 0.1 to about 9.0%, and most preferably from about 0.5% to about 5.0% by weight, based on total weight of the composition, including all ranges subsumed therein. Other optional additives which may be used in conjunction with the substrate enhancing agents of the present composition include known lubricants like silicon comprising compounds, substituted vegetable oils, fatty acids or fatty acid esters and quaternary ammonium compounds and surfactants. The silicon comprising compounds which may be used in this invention include those that may generally be classified as siloxanes, preferably those having a viscosity from about 10 to about one million centistokes at ambient temperature. The siloxanes which may be used in this invention include polydimethylsiloxane; ethoxylated organosilicones; polyalkyleneoxide modified polydimethylsiloxane; linear aminopolydimethylsiloxane polyalkyleneoxide copolymers; betaine siloxane copolymers; and alkylactam siloxane copolymers. Of the foregoing, the preferred siloxane is a linear aminopolydimethylsiloxane polyalkyleneoxide copolymer sold under the name Magnasoft SRS (available from Witco, Greenwich, Conn., USA). Silsoft A-843, another aminopolydimethylsiloxane polyalkyleneoxide copolymer available from Witco, is also a particularly preferred lubricant which may be used. The most preferred siloxane is, however, a polydimethylsiloxane sold under the name HV-600 by Dow Chemical. Regarding the silicon comprising compounds, such compounds are preferably included in the compositions of the present invention in an amount from about 0.1 to about 10%, and preferably, from about 0.1% to about 5%, and most preferably, from about 0.3 to about 1.5% by weight silicon comprising compound (or mixtures of silicon comprising compounds), based on total weight of the composition for improving substrate characteristics, including all ranges subsumed therein. The substituted vegetable oils which may be used in this invention include substituted canola, castor, palm, peanut and corn oil, including mixtures thereof. Regarding the substitution, any groups that increase the water solubility of the oil may be substituted thereon. Such groups include sulphate, sulphonate, phosphate and phosphonate groups as well as polyalkylene oxide groups like polyethylene oxide. As to the degree of substitution, the vegetable oil is substituted to the point where it is almost soluble in water, yet able to lubricate the fabrics it comes in contact with. Typically, from about 0.1 to about 15.0%, and preferably, from about 0.2 to about 10.0%, and most preferably, from about 0.3 to about 5.0% by weight substituted vegetable oil is used. Preferred substituted vegetable oils are sulfated caster oil such as SCO-50 and SCO-75, both made commercially available by B.F. Goodrich. The fatty acid or fatty acid ester which may be used in this invention includes fatty acids or there esters of stearic, oleic, palmitic, lauric, isostearic, myristic or behenic acids, as well as mixtures thereof. It is also understood that the fatty acid or esters thereof which may be used in this invention can comprise a mixture of compositions such as carnauba wax, candelilla wax, and natural or synthetic bees wax. The amount of fatty acid or esters thereof which may be used in the composition of this invention is typically from about 0.1 to about 10.0%, and preferably, from about 0.2 to about 5.0%, and most preferably, from about 0.3 to about 3.0% by weight fatty acid ester, based on total weight of the composition for improving substrate characteristics, including all ranges subsumed therein. The quaternary ammonium compounds which may be used in this invention include any of those typically found in fabric conditioning products. Such quaternary ammonium compounds include dialkyldimethylammonium chlorides and trialkylmethyl ammonium chlorides, wherein the alkyl groups have from about 12 to about 22 carbon atoms. Other quaternary ammonium compounds which may be used are, for example, ester containing quaternary ammonium compounds N,N-di(tallowyl-oxy-ethyl)-N,N-dimethyl ammonium chloride, N,N-di(tallowyl-oxy-ethyl)-N-methyl, N-(2-hydroxyethyl) ammonium chloride and mixtures thereof. The amount of quaternary ammonium compound employed in the composition of this invention is typically from about 0.1 to about 5.0%, and preferably, from about 0.2 to about 4.0%, and most preferably, from about 0.3 to about 3.0% by weight quaternary ammonium compound, based on total weight of the composition for improving substrate characteristics, including all ranges subsumed therein. The only limitation with respect to the surfactant which may be used in this invention is that the surfactant is compatible with the substrate enhancing agent used in the substrate treating compositions of this invention. The surfactants that may be used in this invention include commercially known nonionic, anionic, cationic, amphoteric and zwitterionic surfactants, including mixtures thereof. Such surfactants typically make up from about 0.5 to about 10 wt. % of the total weight of the substrate treating composition. Nonionic surfactants are the preferred surfactants and they are defined to include those surfactants generally classified as fatty acid or alcohol condensates. Such surfactants are typically sold under the names Neodol, Plurafac, Dehypon and Synperonic and made commercially available from suppliers like Shell Chemical Company, Union Carbide, Condea, Stepan and BASF. The preferred nonionic surfactant used in this invention is an ethoxylated nonionic sold under the name Neodol 25-9 and made available by Shell Chemical Company. It is also noted herein that odor reducing additives, like cyclodextrin, may be used in the composition of this invention. Cyclodextrin, as used herein is meant to include cyclodextrins containing from 6 to 12 glucose units; especially, alpha-cyclodextrin, beta-cyclodextrin, gamma-cycodextrin, derivatives thereof or mixtures thereof. The amount of cyclodextrin which may be used is typically from about 0.1 to about 7.0% by weight cyclodextrin, based on total weight of the composition for improving substrate characteristics, including all ranges subsumed therein. A more detailed description of such odor reducing additives may be found in International Application No. WO 98/56890. Still other optional additives which may be used in this invention include well known and commercially available colorants, fragrances such as Koala Kool MOD-C made available by Takasago, preservatives, pH control agents, viscosity adjusting agents such as inorganic salts, hydrotropes such as sodium xylene sulfonate, anti-oxidants such as butylated hydroxy toluene, foam control agents,chelants, enzymes (e.g., lipases, amylases, proteases), dye transfer inhibitors and anti-clogging agents. When used, these optional additives, collectively, make up less than about 10.0% by weight of the total weight of the composition for treating a substrate. The composition for treating a substrate of this invention may be applied to the substrate with, for example, a dispenser like roller, aerosol dispenser, pump sprayer or trigger sprayer. The FIGURE depicts a trigger sprayer 10 having a head 12 , a neck 14 and a bottle 16 . The bottle 16 is connected to the neck 14 via twist connector 18 . Trigger 20 , when engaged, causes the composition for improving substrate characteristics 22 to be drawn through the delivery tube 24 and the exit nozzle 26 in order to deliver the composition for improving substrate characteristics 22 on to a substrate (not shown). The composition for improving substrate characteristics of this invention is preferably applied on to a substrate at portions of the substrate that are most likely to wrinkle. If desired, however, the entire substrate may be subjected to the composition. When applying the composition for improving substrate characteristics, the amount of composition applied is enough to improve the characteristics of the substrate and just enough to allow the substrate to dry (at ambient temperature) in under about three (3) hours, and preferably, in under about one (1) hour, and most preferably, in under about one-half (½) hour. Also, it is noted that after applying the composition of the present invention to the substrate, little or no discernible markings (e.g., stains, water marks or rings) may be found on the substrate when the composition is completely dry. Instructions may be provided with the composition for improving substrate characteristics of this invention. Such instructions, where applicable, educate an end user to apply the composition of this invention to a substrate and then to immediately (e.g., within about five (5) minutes) hang the substrate up or place the substrate on a flat surface. The instructions may also suggest to the end user to apply the composition of this invention to a substrate and then to either tension and smooth the garment or to iron the substrate before or after (preferably after) the composition for improving substrate characteristics dries. The examples are provided to further illustrate and facilitate a better understanding of the compositions for improving substrate characteristics of this invention. The examples are not meant to limit the accompanying claims. EXAMPLE 1–6 A Component 1 2 3 4 5 6 Ethanol 5.0 5.0 2.0 — 4.0 3.0 Sulfated castor oil 0.5 2.0 — — — — Silicone B — — .5 1.0 — 2.0 Ethoxylated nonionic C 1.0 2.0 1.0 — 2.0 1.0 Tallow alcohol 3.0 1.5 — — 5.0 4.0 Methyl methoxy — 2.0 5.0 4.0 4.0 3.0 butanol Ditallow, dimethyl — — — — 2.0 — ammonium chloride Octadecyl alcohol — — 2.0 4.0 — — Fragrance D 0.5 0.5 — 0.5 02 0.5 Water To To To To To To 100% 100% 100% 100% 100% 100% A = Examples 1–6 may be made by mixing the components, in no particular order, under conditions of moderate sheer at temperatures from about 25° C. to about 85° C. B = MagnaSoft SRS (Witco) (Examples 1–5); HV-600 PDMS (Example 6). C = Neodol 25-9 (Shell Chemical). D = Koala Kool MOD-C (Takasago).	The present invention is directed to a composition for improving substrate characteristics. The composition has a substrate enhancing agent, like a monohydric alcohol, and the composition reduces wrinkles in substrates that have not been subjected to ironing.	3
CROSS REFERENCE TO OTHER APPLICATIONS This application is a continuation-in-part of my copending application Ser. No. 204,619, filed Dec. 3, 1971, now abandoned. BACKGROUND OF THE INVENTION This invention relates to a process for stabilizing the fiber orientation and fiber distribution in webs of textile-length fibers which are intended to be eventually processed into non-woven fabrics. More particularly it relates to a process for bonding the fibers of a fibrous web, using short binder fibers, so that they maintain their general positional relationships through subsequent operations of drafting, printing, saturating, drying, winding into roll form, and the like. Nonwoven fabrics are a recognized article of commerce widely used for the formation of disposable or semi-disposable articles such as sheets, pillowcases, hospital gowns and drapes, wiping cloths, dusters, and for a wide variety of other purposes. The most common type of nonwoven fabric is that which is formed by saturating or impregnating with a polymeric dispersion or latex an unspun, unwoven, intermingled array of textile-length fibers delivered from a card, garnett, or air-lay machine. By far the most common web-forming device is a so-called card or carding machine, which comprises a cylinder, three to four feet in diameter, and of any desired width, covered with a multiplicity of fine bent wires called teeth or card clothing. A lap or roll of fibers is fed by means of a so-called licker-in roll to this cylinder, which picks up and carries a fleece or veil of fibers. The fibers are also worked upon by auxiliary rolls or flat strips covered with wire teeth and set in close proximity to the circumference of the cylinder. The fibrous web is removed from the cylinder by a doffing device, which is conventionally a secondary wire-covered cylinder tangential to the main cylinder and revolving in the opposite direction. From the doffer, the web is removed and forwarded for further processing by a vibrating comb or similar device. The conventional card or carding machine was primarily devised to exert a two-fold effect. First, it cleaned an array of fibers such as raw cotton or wool, removing considerable dirt, other foreign matter, and short fibers. Second, it tended to parallelize and rearrange the fibers, which was then a desirable consequence since the fibrous card web was customarily further drafted and spun into yarn in a multi-stage process. With the advent of the nonwoven fabric industry, however, many cards were converted from their original function of preparing a sliver of parallel fibers to delivering a full-width web or a plurality of such webs to a conveyor belt, for subsequent bonding to form a nonwoven fabric. One of the previous advantages of carding, parallelization of the fibers, became a distinct disadvantage in the preparation of nonwoven fabrics. Spun yarns have strength only in the lengthwise direction, where the strength is needed for conventional weaving purposes, whereas the majority of nonwoven fabrics must have at least some minimal tensile strength in the transverse or cross-web direction. The problem is particularly acute in the case of nonwoven fabrics prepared from man-made fibers, which, although they may be crimped, are generally straighter and much more readily oriented than natural fibers such as cotton. A further complication is that the conventional processing of bonded nonwoven fabrics consists of a set of stages -- conveying, saturating, drying, winding, etc. -- all of which impose a further drafting and parallelizing effect on the fibrous web, since the web is being stretched under tension in each of these operations. If a web is carefully removed from the doffer of a card and then is bonded to form a nonwoven fabric with careful handling to avoid drafting or distortion, the longitudinal (machine direction or M.D.) tensile strength may be only 3 or 4 times the lateral (cross-direction or C.D.) tensile strength. In conventional multi-stage bonding and drying operations, however, wherein the web is pulled under tension in each processing stage, tensile strength ratios of 10 or 20 to 1 are found, M.D. to C.D. Various expedients are resorted to for improving what will hereinafter be referred to simply as the strength ratio, it being understood that this refers to the ratio of strength in the machine or longitudinal direction to the cross or lateral direction. One expedient is to disperse the fibers in more or less random orientation into an air stream, from which they are collected on a perforated rotating drum by suction. Such devices are expensive, and clumping and poor fiber dispersion appear at the speeds of 30 to 50 yards per minute at which it is economical to process nonwoven fabrics. Another common method of improving the strength ratio is by means of a cross-laying device, whereby a full-width web of oriented fibers is mechanically pleated back and forth across a conveyor belt to build up a composite batt in which the average angular displacement of the fibers is alternated. Such devices again are slow, cumbersome, and are suitable only for batts of substantial thickness where fold marks and overlap ridges are not objectionable. Other auxiliary devices have been proposed to randomize carded webs, such as that set forth in U.S. Pat. No. 3,538,552 to J. L. Foley, of common assignee. Still other devices for creating webs in which the fibers lie in more or less random orientation are described in my copending application Ser. No. 159,229, filed July 2, 1971, and U.S. Pat. No. 3,727,270, issued Apr. 17, 1973. In these applications, textile-length fibers are accelerated and drafted through aspirators, diffused and decelerated in a plenum chamber, and eventually collected in the form of randomly-oriented webs. However, as set forth above, devices which randomize fibrous webs from the various types of web-forming devices are generally ineffective in maintaining a favorable M.D. -- C.D. strength ratio during the subsequent operations of saturating and drying, which are essential steps in the preparation of most bonded nonwoven fabrics. The fibrous webs are drawn or drafted through the bonding and drying steps, and since the fibers are only casually engaged by frictional forces, they become gradually more and more oriented in the machine direction -- that is, lengthwise of the web. In this way, a random web which is delivered from the web former with approximately the same crosswise as lengthwise strength may show a M.D. tensile strength which is 4 or 5 times the C.D. strength after complete processing. In products where the C.D. strength is a controlling or essential factor, this means that the nonwoven fabrics must be made heavier than need be, to meet the minimum crosswise strength requirement, which is a wasteful expedient. This invention is directed toward the use of short thermoplastic, thermoretractile fibers as a prebond for increasing the strength ratio of a web preliminary to the subsequent operations of saturating, drying and the like. It is known to subject fibrous webs comprising a mixture of thermoplastic and non-thermoplastic fibers to heat, in order to form a nonwoven web, as taught by Reed in U.S. Pat. No. 2,277,049 and by Harrington, Jr. et al in U.S. Pat. No. 3,229,008. However, the teaching in both such instances relates to carded or garnetted webs in which both the thermosensitive and non-thermosensitive fibers are of textile-length, that is, capable of being formed into webs by dry-lay mechanical processing. These thermosensitive fibers have sufficient length, therefore, to become reticulately entwined with the similarly long non-thermosensitive fibers. Since these fibers are entwined, or interlaced, with adjoining fibers, then, upon heating in the absence of pressures, when these thermosensitive fibers go through the process of retraction or fiber shrink, they pull the non-thermosensitive into an area contraction. This shrinkage of the textile-length thermosensitive fibers sets up a shrinkage tendency in the web as a whole, since the retracting fibers, spanning over, and interlaced with, many non-thermosensitive fibers draw these fibers together as retraction sets in. As a practical matter, therefore, the bonding processes in U.S. Pat. Nos. 2,277,049 and 3,229,008 are always carried out under pressure if undesirable shrinkage is to be avoided. Although the use of a pressure nip has eliminated this shrink, it has done so under the penalty of compressing the fabric, destroying its loft, and introducing processing difficulties. Accordingly, it is an object of this invention to provide a process for making a web of mixed thermosensitive and non-thermosensitive fibers which can be heated at zero pressure to activate the thermosensitive (binder) fibers without significant shrinkage of the web, while enhancing the homogeniety of the distribution of those binder fibers within the web. It is another object of the present invention to provide a process that stabilizes the fibers in an air-laid randomly oriented web against the gross distortion and reorientation which they normally are subject to in subsequent bonding and drying operations. It is a further object of the invention to provide a method of making a bonded air-laid web wherein a substantial number of the fibers in the web are bonded only at their crossover points, whereby the web remains flexible, and substantially uncondensed. Still another object of the invention is to provide a process that limits the maximum size of the bead resulting from the melting of a thermoplastic fiber. SUMMARY OF THE INVENTION The relative orientation and distribution of the fibers in an air-laid web is stabilized by means of a zero pressure thermoplastic prebond. The web is formed of non-thermally sensitive fibers having admixed therewith in random distribution and oriented throughout the length, breadth and depth of the web, a minor proportion of short fibers of a drawn, thermoplastic and thermoretractile nature which liquefy at a temperature below the melting point of the non-thermally sensitive fibers. The mixed fiber web is heated, at zero pressure, to a temperature sufficient to cause the drawn, thermoretractile fibers to retract and melt to a series of fluid beads with substantially complete loss of fiber identity, the beads locating principally at the crossover points of the non-thermally sensitive fibers. When the web is cooled, the fluid beads solidify so as to act as a restorative force that stabilizes the relative orientation and distribution of the non-thermally sensitive fibers. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow sheet of the steps comprising the process of this invention; FIG. 2 represents a side elevation, partly broken away, of one type of apparatus suitable for carrying out the process of this invention; FIG. 3 is a magnified view of the section A of FIG. 2, enclosed by dotted lines; FIG. 4 is a top elevation, partly broken away, of the fiber-orientation section of FIG. 2; FIG. 5 is a magnified side view of the section 22 of FIG. 2; and, FIG. 6 is a representation of a typical product of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic steps of the present invention comprise the formation of an air-borne diffusion of a minor proportion of short thermoplastic and thermoretractile fibers, preferably between 0.05 and 0.40 inches in length, together with a major portion of fibers which are not thermally sensitive at the temperature at which the thermoretractile fibers are affected; collecting the mixture of fibers in the form of a fleece or web in which both types of fibers are randomly arrayed; subjecting the mixed fiber web to a heating operation, without pressure, to cause the thermoretractile fibers to retract and melt into a series of fluid beads, with substantial loss of fiber identity; and cooling the web until the beads formed from the thermoretractile fibers have solidified, so as to act as a restorative force that stabilizes the relative orientation and distribution of the non-thermally sensitive fibers. As may be seen from the flow diagram, FIG. 1, various methods of initial fiber preparation are used, depending on fiber length, as explained below. The different classes of fibers are fed through air jets to form a mixed fiber diffusion in a fluid stream, usually air, said machine terminating in a porous screen onto which a mixed-fiber web is deposited, for subsequent bonding and winding up. If space allows, further processes of saturating or printing may be done in-line, bypassing the winding operation. The heating process is carried out while the fibers are randomly arrayed and in unstressed condition, preferably supported on an air-permeable conveyor belt. In this manner, the non-thermally affected fibers are bonded at a sufficient number of their points of intersection that although the web is open, porous, and flexible, and although the fibers are capable of temporary displacement, there is a constant restorative force that minimizes the permanent drafting -- i.e., slippage of fiber past fiber -- and hence minimizes the tendency of subsequent operations to reorient the fibers into a direction more nearly parallel to the machine direction of the web. In the present invention, on the other hand, the thermoplastic and thermoretractile fibers are short, and are heated under substantially zero pressure, until their identity as fibers is completely lost, and they appear as beads or droplets of thermoplastic material substantially all of which are located at the crossover points where the non-thermosensitive fibers intersect. Because of the short length of these fibers, they are not interlaced with adjoining fibers, and, therefore, do not cause web shrinkage -- even at zero pressure. As may be seen from the flow sheet, FIG. 1, a mixture of fibers of different lengths is fed to a plurality of aspirator jets, which in turn create an air-borne diffusion of intermingled and substantially individualized fibers, relatively free of clumps and fiber clusters. The nature of the feeding device supplying the fibers to the jets will of course vary with the fiber length and the nature of the fiber. Long fibers, 3 to 9 inches, may be processed into a top on the wool system, well known and needing no description here. Alternatively, a tow of continuous filaments may be cut on a Pacific Converter and pin-drafted to form a top of long staple fibers. Equally well known is the formation of shorter staple fibers into a sliver, using the cotton system of sliver preparation. The short thermoplastic fibers, which may be mixed with equally short or shorter papermaking fibers (fluff fibers), may be fed to the aspirator jet by a variety of methods known in the art. One such method is to strip a veil of short fibers from a rotating toothed card or garnett roll, as by means of a vacuum slot operating at a vacuum of 10 to 30 inches of water, and to pipe the resulting air stream of short fibers to the jet for further diffusion and blending with the non-thermally sensitive fibers. Alternatively, processes such as are set forth in U.S. Pat. Nos. 3,577,290 or 3,616,035, to R. J. Baskerville et al, may be employed. These latter processes include the step of cutting a tow of continuous filaments into short staple fibers which are then diffused in air. Again referring to FIG. 1, fibers of different staple lengths, from a plurality of jets, are fed to an air-lay machine. There are numerous ways of forming an air-borne diffusion of mixed fibers, and of collecting the fibers from the air stream in the form of a random web. The method set forth here is described in detail in my U.S. Pat. No. 3,812,553, and should be regarded as illustrative, not restrictive. Referring to FIG. 2, there is shown a pair of fluid-powered jets or aspirators, 10 and 11, each capable of converting a top or sliver or similar feed of staple fibers into high-velocity streams of substantially individualized fibers. Such jets, their parameters, and their function are described in detail in my U.S. Pat. No. 3,793,679 and U.S. Pat. No. 3,727,270, and there are also commercially available aspirators capable of performing a similar function. The high-velocity fluid streams of fibers are directed into the entry chamber 12, and thence are diffused into a guiding chamber 14, which, as seen by comparing FIGS. 2 and 4, reforms the fibrous streams into a stream which is wider and shallower than the diffuse streams emerging from the aspirator. The wide and shallow fibrous stream flows then through the chamber 16 and preferably to a constricting region 18, which acts as a Venturi. While not absolutely mandatory, this constriction 18 serves to iron out or minimize local disruptive pressure difference or vortices, thus evening out the flow of fibers. From the Venturi section 18 the fibrous stream passes past the adjustable baffle or "spoiler" 20, which when in the position shown in FIG. 2 disrupts the smooth fluid flow of fibers, creating turbulence in the form of innumerable vortices and inequalities of air pressure in the centrifugal chamber 22, as shown in magnified detail in FIG. 5. In this manner, the centrifugal chamber 22 will be seen to be more or less uniformly filled with a randomly-oriented and dispersed stream of mixed fibers. Such streams of fibers yield webs which are substantially equal in M.D. and C.D. strength. As explained in U.S. Pat. No. 3,812,553, the degree of reorientation can be controlled by the action of the spoiler 20, and can be more readily understood by reference to FIG. 3. The spoiler, as it is known in aerodynamic parlance, is a device which disrupts or disturbs the smooth flow of an air stream. As seen in partially broken-away FIG. 3, which is an enlargement of the dotted-line section A of FIG. 2, one convenient form of spoiler 20 consists of a right-angle bend of sheet metal, extending across the width of the curved centrifugal chamber 22, and hingedly connected as at 21 to the centrifugal chamber 22 so that it can be adjusted to extend downwardly into the fibrous stream. Other forms of adjustable baffle or spoiler will readily occur to those skilled in the art. If the spoiler is adjusted so that the vertical section or wing 23 of FIG. 3 is swung to a horizontal position parallel to the upper surface of the centrifugal chamber 22, there will be minimal interference with the smooth flow of the fibrous stream, and the long fibers in the stream will be predominantly oriented in the cross direction. Intermediate positioning of the wing 23 between horizontal and vertical will result in intermediate ratios of M.D. to C.D. strength in the resulting webs. Whatever the degree of fiber orientation established in the centrifugal chamber 22, the curving stream of fibers passes downwardly and is collected on the porous screen 24, driven by rolls 36 and 38 as shown in FIG. 2. In order to prevent leakage in the transfer of the fibrous stream to the belt 24, a sealing roll 28 rotates on the screen blocking the egress of fiber-laden air from the front edge of the end of the centrifugal chamber 22, and a curved plastic strip 26 sealed to the lower rear edge of the centrifugal chamber 22 rides in contact with the moving screen, as shown more clearly in FIG. 5. The size of the apparatus will naturally vary with the width of web to be produced, the volume of fiber to be processed, and with other factors. A typical set of dimensions might involve an entry chamber 12 in the form of a 10 inch cube. The guiding chamber 14 may taper down to a 4.5 l inch depth, while widening out to 40 inches for the purpose of producing a 40 inch-wide web. The chamber 16 may be 40 inches wide and 4.5 inches deep, with a cross section of 180 square inches. The outlet slot of the Venturi section 18 may taper down to a depth of about 1.2 inches, ejecting a fibrous stream into the 2 inch deep opening of the centrifugal chamber 22. The guiding surfaces of this centrifugal chamber 22 are curved in a 15 inch radius through a 90° turn, terminating in an outlet section 6 inches wide, thus giving a 240 square inch screen deposition area. The above dimensional parameters are illustrative only, and not restrictive. Engineering details for modifications of the apparatus may be made, bearing in mind that the centrifugal force developed is proportional to the square of the velocity of the air stream, and inversely proportional to the radius of curvature. As seen in FIG. 2, the resulting fibrous web 34, carried on the porous conveyor 24, is subjected to a heating process while it remains in a substantially uncompressed condition. Various types of heating devices may be used, the instant illustration being one in which a stream of hot air from a heater 30 is drawn down through the web by means of a vacuum box 32, from which the exhaust hot air may be recycled (not shown). Depending on the web weight, the concentration of thermoplastic fiber, and on the processing speed desired, the air temperature in the hot air source may vary from 400° F to 1,000° F. Also as noted in FIG. 2, it is desirable that the heating operation, which liquefies the thermoplastic fibers to fluid beads, be carried out on the web while the web is still supported on the porous screen on which it has been formed, and before any substantial drafting stress has been applied to the web. In this manner, the bonded products resemble the nonwoven fabric shown in FIG. 6, where for the sake of clarity only a few fibers are shown, in magnified detail, comprising a substantially random array of non-thermally sensitive fibers 40, hingedly interconnected to each other by fused beads of thermoplastic material 42. Occasionally there will be found beads of thermoplastic material 44 which encircle a solitary fiber, but the majority of the short thermoplastic and thermoretractile fibers retract and melt down in the heating process in such a fashion that they bond together two or more non-thermally sensitive fibers. In the heating operation which effects the bonding, thermal retraction occurs before fusion. As mentioned above, in order to avoid shrinkage of the web as a whole, it is desirable that the thermally sensitive fibers be between 0.05 and 0.40 inches long, a range of 0.2 to 0.3 inches being especially preferred. The use of such short fibers advantageously insures that there is a widespread distribution of potential binding points because of the larger number of short fibers in a given fiber weight; that substantially no shrinkage of the web as a whole will occur, even at zero pressure; and that a more efficient use of the thermoplastic binder material will be achieved. Preferably, the thermosensitive fibers employed are only 0.2 to 0.3 inches in length when non-thermosensitive fibers of 1 to 2 inches in length are to be bonded. When non-thermosensitive fibers of 3 to 9 inches are to be bonded, the thermosensitive fibers may range up to 0.4 inches in length. With shorter non-thermosensitive fibers, the length of thermosensitive fibers may be as low as 0.05 inches. Since fibers of 0.05 to 0.4 inches cannot be carded or garnetted, the mixed fiber web of the present invention is formed in an air-lay system, such as is described above. Another advantage in the use of short thermoplastic fibers is that the size and weight of such fibers, when melted to a bead, is much less than when textile-length thermoplastic fibers are used. Reduction of fiber to bonding beads is more complete with short fibers, with the formation of a large number of small bonding points, rather than a smaller number of larger beads. It has been found that with the use of short (0.4 inch or less) thermoplastic fibers, there is a greater tendency for the molten beads to concentrate at the crossover points of the larger non-thermoplastic fibers, with the consequence that the basic binder material is much more efficiently utilized. As thermally sensitive fibers, there may be employed a wide variety of "binder fibers," as they are termed in the nonwoven industry: polyolefin fibers, undrawn polyester fibers, low-melting polyamide fibers, plasticized cellulose acetate fibers, copolymerized polyvinyl chloride-polyvinyl acetate fibers, and the like. Polyolefin fibers and polyvinyl chloride-polyvinyl acetate fibers are especially preferred. The major portion of the fibers comprises non-thermally sensitive fibers or mixtures thereof, any stable textile fiber being suitable provided that there is a suitable discrepancy -- for example, +100° F -- between the melting point of the thermally sensitive fibers and the temperature at which the non-thermally sensitive fibers are affected. Fluid-borne streams of such fibers may utilize staple fibers which vary from 1 or 2 inches in length to 6 or 8 inches, or even longer. The formation of such fluid-borne streams is set forth in detail in my copending applications Ser. Nos. 159,229; 248,106; and U.S. Pat. No. 3,727,270. Of course, various other expedients for forming a fluid-borne stream of intermingled long and short fibers may readily suggest themselves to those skilled in the art. The invention will be illustrated by the following examples: EXAMPLE 1 Using the apparatus depicted in FIG. 2, a fluid-borne stream of 1.5 inch 1.5 denier viscose fibers was diffused from one aspirator and a fluid-borne stream of 0.25 inch 3 denier polyvinyl chloride-polyvinyl acetate fibers was diffused from the other aspirator, forming a mixed diffusion of air-borne fibers which was randomized in the centrifugal chamber 22 with the spoiler as shown in FIG. 3. The web, supported on the porous screen 24, was subjected to a hot air treatment, without pressure, by the hot air blower 30 and vacuum box 32, the air temperature being about 450° F. The final product weighed 10 grams per square yard and consisted of 80% rayon fibers, 20% vinyl copolymer in the form of small, essentially sperical beads, as in FIG. 6, said beads being located principally at the crossover points of the rayon fibers. The fabric had a tensile strength of 77 grams per inch-wide strip in the machine direction and 118 grams in the cross direction: tear strengths 68 grams machine direction, 50 grams cross direction. EXAMPLE 2 Using the same apparatus as in Example 1, a fluid-borne stream of 1.5 inch 1.5 denier viscose fibers was diffused from one aspirator, and a stream of intermingled 0.25 inch 3 denier polyvinyl chloride-polyvinyl acetate fibers and paper fluff fibers of between 1,000 and 3,000 microns in length was diffused from the other aspirator. The mixed diffusion of the three types of fibers was again randomized in the centrifugal chamber 22 with the spoiler as shown in FIG. 3. Hot air bonding was carried out as in Example 1 without pressure. The bonded product, again showing the characteristic bead-like bonding of FIG. 6, weighed 25 grams per square yard and was composed of 25% viscose fibers, 37.5% paper fluff fibers, and 37.5% fused vinyl copolymer. The tensile strengths were 222 grams per inch-wide strip machine direction, 185 grams cross direction. Tear strengths were 172 grams machine direction, 149 grams cross direction. EXAMPLE 3 Again using the apparatus of Example 1, a fluid-borne stream of 0.25 inch 1.5 denier viscose fibers, 50% by weight, blended with 50% by weight of 0.25 inch 3 denier polyvinyl chloride-polyvinyl acetate fibers was diffused through one aspirator, and a fluid-borne stream of 6 inch 6 denier nylon fibers was diffused through the other aspirator. The mixed diffusion of the three types of fibers was again randomized in the centrifugal chamber 22 with the spoiler as shown in FIG. 3. Hot air bonding was carried out as in Example 1 without pressure. This product also resembled the fabric of FIG. 6. It weighed 35 grams per square yard, and was composed of 30% viscose fibers, 40% nylon fibers, and 30% fused vinyl copolymer. The tensile strength in the machine direction was 740 grams per inch-wide strip, 1200 grams in the cross direction. Tear strengths were 730 grams machine direction, 1085 grams cross direction. The bonded products of the three examples showed that a substantial number of the non-thermosensitive fibers were hingedly interconnected at their crossover points, so that all three products could be processed through subsequent stages of saturating, print bonding, laminating to tissue or other substrates, drying, slitting, and winding without destroying the essentially isotropic distribution of the fibers.	Air-laid fibrous webs are formed from randomly-oriented mixed fibers containing a minor proportion of short, flock-length, thermoplastic and thermoretractile fibers. The air-laid web is then heated, without pressure, to cause melting of the thermoplastic fibers to the point of substantially complete loss of fiber identity. The relative orientation of the web thus formed is stabilized so that the fibers therein maintain their general positional relationships through subsequent stresses incurred during the operations of printing, saturating, drying, winding into roll form and the like.	3
BACKGROUND Large antennas are mounted on light-weight non-rigid structures can pose a number of significant challenges, including antenna shape distortion and transmit and receive channel propagation parameters. Non-rigid antennas can be distorted by numerous mechanical and thermal loads which may vary with time, possibly at high rate. Small distortions can significantly degrade the antenna performance. For example, a linear distortion of 3-cm across an X-band aperture displaces the beam by a full beamwidth; random distortions of less that 1-cm will destroy the beam quality. The electrical properties (phase and transit time) of the channels connecting the various elements of the antenna may change with time. Small uncompensated changes in phase and transit time can destroy the beam focus. U.S. Pat. No. 6,954,173 describes techniques for measurement of deformation of electronically scanned antenna array structures. SUMMARY OF THE DISCLOSURE Methods for determining parameters for an array are described. An exemplary embodiment of a method determines a set of parameters for an antenna array including multiple array elements, the array being fed by a feed array including a plurality of feed elements. The embodiment of the method includes measuring a plurality of bistatic ranges Rijk through different signal path combinations, each signal path combination from a feed element “i,” to an array element “j,” and to a feed element “k”. The measuring includes radiating energy from feed element “i”, and reflecting some of the radiated energy from array element “j” back to feed element k of the feed array. The measured bistatic ranges are processed to solve for the set of parameters. Another embodiment of a method is for measurement of multiple array elements of an array, and includes radiating energy from one or more array elements, reflecting some of the radiated energy from a set of reflector elements back to the array elements each reflector element having a variable phase shifter associated therewith, cycling each reflector element phase shifter through a range of phase shifter settings at a unique rate, processing the received signals to extract a phase of the reflected energy as received at each element; and using the extracted phase for each element to determine a relative location of each array element. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an exemplary embodiment of an array antenna including an array of feed elements which are grouped into subarrays, each subarray with its own exciter/receiver. FIG. 2 is a schematic view illustrating an exemplary determination of a bistatic range R ijk by measuring the difference in the phase of the signal arriving at neighboring feed elements. FIG. 3 is a schematic diagram illustrating an exemplary array antenna and an exemplary technique for measuring a large number of pairs of elements simultaneously, without a switching network. FIG. 4A is a schematic diagram of an exemplary array antenna and a measurement technique involving switching the lens phase shifters at an element-unique rate. FIG. 4B shows an example spectrum in which the lens phase shifter rates are separated by a rate which exceeds the highest shifting rate of any of the feed elements. FIG. 5 schematically illustrates an exemplary embodiment of a reflector which is fed by an array feed. FIG. 6 schematically depicts an exemplary embodiment of an electronically scanned array and an arrangement of a plurality of retro-reflector devices. DETAILED DESCRIPTION In the following detailed description and in the several figures of the drawing, like elements are identified with like reference numerals. The figures are not to scale, and relative feature sizes may be exaggerated for illustrative purposes. Exemplary embodiments of a technique for calibrating antennas to compensate for physical distortion of the antenna shape as well as for variations in the properties of the electronic components are described. An exemplary embodiment of the calibration process may be executed at high rate (to accommodate rapidly varying antenna parameters) and with little interruption of the nominal operation of the antenna. In an exemplary embodiment, array phase shifters may be used to introduce an element-unique code which can be decoded in the receiver to determine the locations and channel propagation parameters of the antenna components. Degradation of beam quality due to antenna distortion and varying channel propagation parameters may be mitigated by applying a phase and/or time correction to the array or (in the case of array-fed reflectors) to the array feed. Proper selection of the correcting phase/time may involve only knowledge of the distortion and the channel propagation parameters. If accurate and timely knowledge of the distortion is available, the beam can be restored simply by making an appropriate electronic correction to the array elements. Consider the array antenna 50 depicted in FIG. 1 , including an array feed 60 of N i elements 62 - 1 , 62 - 2 . . . 62 -N i grouped into subarrays 60 A, 60 B, each subarray with its own exciter/receiver 64 A, and 64 B. Each element 62 - 1 , . . . 62 -N i has a respective phase shifter 66 - 1 , . . . 66 -N i associated therewith. For the purpose of this initial discussion, assume further that the array feed 60 illuminates a space-fed lens 80 having N j elements 82 - 1 , 82 - 2 . . . 82 -N j , each with one of phase shifters 84 - 1 , 84 - 2 . . . 84 -N j employed to steer the beam, and a radiating element 90 - 1 , 90 - 2 , . . . 90 -N j . In addition, without loss of generality, assume that the phase shifters of each lens element may be switched between the respective radiating element and a reflective load or terminator 86 - 1 , 86 - 2 . . . 86 -N j . by switches 88 - 1 , 88 - 2 . . . 88 -N j . In an exemplary embodiment, to generate a coherent beam in a desired direction, accurate knowledge may be obtained of the following: Seven feed parameters for each feed element “i”: element position (x i f , y i f , z i f ), transmit channel parameters (phase Θ i t and time delay t i t ), and receive channel parameters (phase Θ i r , and time delay t i r ); Five lens parameters for each lens element “j”: element position (x j l , y j l , z j l ), transmit channel parameters (phase Θ j l and time delay t j l ) With the above parameters, the array phase shifters and time-delay units (if available) can be adjusted to compensate for the distortion. In an exemplary embodiment, to determine the desired feed and lens parameters, the bistatic range R ijk is measured from feed element “i,” to lens element “j,” and finally to feed element “k”. The bistatic range is measured for a sufficient number of combinations of feed/element paths to solve for the unknown parameters. An exemplary process for deriving the parameters is the following. Define a vector “V” of these unknown parameters for a feed of N i elements and lens of N j elements: V=[F 1 , . . . , F i , . . . , F Ni , L i , . . . , L j , . . . , L Nj ] where F i =position and electrical parameters of the i th feed element=[x i f , y i f , z i f , Θ i t , t i t , Θ i r , t i r ] L j =position and electrical parameters of the j th lens element=[x j l , y j l , z j l , Θ j l , t j l ] Define also a measurement vector M of the bistatic range measurements M=[R 111 , . . . , R ijk . . . . ], and a matrix “G” defining the linearized geometric equations relating the measurements to the unknown parameters, M=GV These linearized equations may then be employed to determine the desired feed and lens parameters which yield the best RMS fit to the bistatic range measurements V rms =(G T W −1 G)H T W −1 M where W is the covariance of the measurement noise. Following the above procedures, the desired feed and lens parameters (vector “V”) can be derived from a suitable set of bistatic measurements. Once the parameters are known, they may be applied to determine the phase and time correction to be applied to each fed and lens element to focus the beam in a desired direction. In an exemplary embodiment, the desired bistatic range R ijk may be determined by measuring the difference in the phase of the signal arriving at neighboring feed elements. An exemplary technique for accomplishing this is shown in FIG. 2 . An arbitrary feed element “i” radiates a coherent signal that impinges on lens element “j”. A portion of the energy incident on lens element j will enter the lens phase shifter and (when the terminator load is switched to be reflective) will scatter energy toward the feed. Some of this backscattered signal will impinge on feed elements “k” and reference element “N i ”. The phase difference of signals received at elements k and N i is measured. The phase difference Δφ between the signal arriving at feed element k (bistatic path R ijk ) and N i (bistatic path R ijNi ) may be used to determine (Mod λ) the differential path length ΔP between the two paths as follows: Δ P =λ(Δφ/2 π+ N ) where the integer N (0, 1, 2, 3, . . . ) accounts for the ambiguity in translating the measured phase difference into a range difference. In an exemplary embodiment, the translation of the position and electrical parameters into a bistatic range employs conversion of the electrical parameters (Θ, t) to range R=c(t+Θ/2πf), where c=speed of light and f=frequency of the signal. This translation is included in the G matrix. Note that the bistatic measurements can be taken at multiple frequencies (to increase the number of measurements). In addition, measurements at two frequencies may be employed to resolve ambiguity between time and phase. The process of resolving the range ambiguity is commonly known as “phase unwrapping.” Although the unwrapping process for some situations can be complex (or perhaps not even possible), it is easily accomplished in an exemplary application of interest here since the feed elements are closely spaced. Specifically, since adjacent elements are typically less than half-a-wavelength apart, the phase difference will be less than one wavelength. Thus, in this case, there is no ambiguity between adjacent elements. Although there is a potential for ambiguity between widely spaced elements, this ambiguity may be resolved by “walking along” a path of the elements which lie between the subject elements. Unwrapping in this fashion is easily accomplished and is routinely done for many applications, including terrain mapping with interferometric synthetic aperture radar data. The phase measure process described above may typically be encumbered by two factors as follows: 1) Phase detector insertion. In order to measure the phase difference between neighboring feed elements, a phase detector may be connected to the output ports of each pair of elements of interest. If this were done in the conventional manner, an extensive network would be needed to connect all desired pairs of elements. Not only would such a network introduce complexity into the system, but in addition it might alter the phase and time delays associated with the various channels. Specifically, the path lengths of the network would likely differ from the path that the signal travels in propagating from the elements to the associated exciter or receiver. 2) Sequential measurement process. If the phase detector were sequentially cycled through each combination of pairs of feed elements, the process would likely take a long time and thus interfere with the normal operation of the antenna. A technique of measuring the phase of many (or all) elements simultaneously is desired. FIG. 3 illustrates an exemplary technique for measuring a large number of pairs of elements simultaneously, without requiring a switching network. The technique employs the element phase shifters to inject an element-unique code which enables the processor to extract the desired phase for all pairs of elements simultaneously. The technique is as follows: A single element (i in FIG. 3 ) of the feed emits a signal of specified frequency. This signal impinges on each lens element, enters the lens element phase shifter, is reflected from the termination, returns through the phase shifter, and back toward the feed array where it impinges on each of the feed receive elements. The beam steering controller 100 directs the phase shifter associated with each receive feed element to change phase at an element-unique rate ω i . The phase switching of all elements is performed in unison at a rate f s at times t=N/f s , where N=0, 1, 2, 3 . . . . At each switching time, the phase shifter associated with the ith element is set to φ i =ω i *N/f s . In the case of discrete phase shifters, the discrete value nearest the desired value is used. The outputs from each array element are combined and fed to the receiver ( 64 B in this example) via the conventional receive network. The composite signal from the receiver is processed with an FFT 200 which generates a spectrum 202 with a series of peaks, each peak corresponding to one of the element-unique frequencies ω i which were directed by the beam steering computer. The phase of the signal received at each element is extracted from the FFT. At each frequency ω i , the phase of the received signal is computed as φ i =tan −1 (Imag FFT(ω i )/Real FFT(ω i )) The measured phases φ i of the feed elements are then unwrapped at 210 to determine the desired bistatic ranges, from which the element locations and channel propagation parameters are determined. The discussion above tacitly assumes that the lens consists of a single element. Since the lenses of interest may have many elements, the returns from the multiple elements can conflict with the desired return from any single lens element. This can be avoided by switching the lens phase shifters at an element-unique rate (in addition to shifting the feed element phase shifters as discussed above.) FIGS. 4A-4B illustrate the concept. The beam steering controller directs the phase shifter associated with the “j th ” lens element to change phase at an element-unique rate ω j . As before, the beam steering controller also directs the phase shifter associated with the “i th ” feed element to change phase at an element-unique rate ω i . The set of feed shifter rates ω i and lens shifter rates ω j can be chosen to avoid overlaps. FIG. 4B shows an example spectrum in which the lens phase shifter rates are separated by a rate which exceeds the highest shifting rate of any of the feed elements. As shown in FIG. 4B , all desired tones are separated in the receiver spectrum. Thus the desired bistatic ranges R ijk can be isolated and determined. The forgoing discussion focused on determining the bistatic range between a single transmit feed element and pairs of lens and feed receive elements. The concept can readily be extended to include additional transmit feed elements as well. This could be accomplished by using the beam steering controller to also direct the feed phase shifters to switch at a unique rate during transmit. By choosing appropriate shifting rates, overlaps in the receive spectrum can be avoided such that all combinations of lens, transmit feed, and receive feed elements can be measured. The previously described exemplary embodiments employ passive elements which may be switched to a reflective terminator so as to reflect a phase-shifted signal. The concept can be extended to employ active devices which also amplify the signal. Such amplification may be of value to applications in which a strong return signal is desired. The technique can be applied to array-fed reflectors. FIG. 5 schematically illustrates an exemplary embodiment of a reflector 200 which is fed by an array feed 60 . In reflector applications, the reflector surface 210 can be populated by retro-reflector devices 220 which have a phase-shifter 222 and a switchable termination including a switch 224 selectively coupling the phase shifter to an absorptive load 226 or a reflective termination 228 . The switchable termination provides two modes as follows: Reflective mode, with the switch 224 connecting the reflective termination to the phase shifter 222 , in which the incident energy from the feed 60 is passed through the phase shifter 222 and then directed back toward the feed 60 . By changing the phase shifter at a unique rate, the bistatic path can be detected and uniquely identified in the receiver. In this manner the location of the phase center of the device can be determined using the processes described above. This phase center will be directly related to the reflector surface on which the device is mounted. Passive mode, with the switch 224 connecting the absorptive load to the phase shifter, in which the incident energy for the feed 60 is absorbed for the most part. This mode is used during nominal operation of the antenna to assure that the calibration signals do not interfere with the nominal functions. The technique can be applied to conventional electronically scanned arrays (ESAs) as well. FIG. 6 schematically depicts an exemplary embodiment of an ESA 300 and an arrangement of a plurality of retro-reflector devices 320 , each connected to a phase shifter 322 , in turn selectively connected by a switch 324 to an absorptive load or a reflective termination 328 . By placing the retro-reflector devices 320 within the field-of-view of the ESA, the ESA can use the devices to determine the positions of its array elements and their associated channel propagation parameters, using the techniques described above with respect to FIGS. 1-4B . The locations of these reflectors does not need to be known (the locations are derived in the process). The use of bistatic range measurements to determine the locations of the desired array elements has been described above. It should be noted that measurements of one-way range differences between an element and a reference element such as a coherent source or sources could as well be sufficient to locate the desired elements. The technique is capable of self-surveying the coherent sources and array elements when a sufficient number of coherent sources are within the antenna's field-of-view. Specifically, the redundancy in coherent sources enables their location to be determined along with the locations of the desired array elements. The discussions above have addressed the problem of determining the relative locations of the array elements, lens elements, and reflector surface relative to each other. Knowledge of these relative locations is sufficient to form a coherent beam, although it is not sufficient to determine the direction of the beam. In order to determine the direction of the beam, the relative locations are translated into a coordinate system common to the target. This can be accomplished by selecting some appropriate elements to serve as reference elements whose locations are know in a coordinate system common to the target. In the case of a three-dimensional scanning antenna, knowledge of the locations of three suitable elements is adequate to establish this relationship. The techniques described above are equally applicable to transmit and receive antennas. Exemplary techniques for calibrating antennas to compensate for physical distortion of the antenna shape as well as for variations in the properties of the antenna's electronic components have been described. The calibration process can be executed at high rate (to accommodate rapidly varying antenna parameters) and with little interruption to the normal operation of the antenna. Exemplary embodiments of the techniques described herein eliminate the dependence on precisely located coherent sources. This is accomplished by making a sufficient number of bistatic (or one-way) range measurements between various elements of the antenna such that the elements can be “self-located.” Exemplary features of the techniques may include one or more of the following: 1) Use of the antenna's existing components (phase shifter, phase shifter controller, transmitter, and receiver) to implement the calibration process. 2) Use of a unique switching frequency for each array element which enables the system to simultaneously measure the desired parameters of all components. 3) Ability to measure all components sufficiently fast to be useful for antennas which experience rapidly changing parameters. 4) Does not require coherent sources at accurately surveyed locations. 5) May be applied to principal types of antennas, including conventional planar ESAs, array-fed lens antennas, array-fed reflector antennas, and conventional reflector antennas. Although the foregoing has been a description and illustration of specific embodiments of the subject matter, various modifications and changes thereto can be made by persons skilled in the art without departing from the scope and spirit of the subject matter.	Methods and apparatus for determining parameters for an array are described. An exemplary embodiment of a method determines a set of parameters for an antenna array including multiple array elements, the array being fed by a feed array including a plurality of feed elements. The embodiment of the method includes measuring a plurality of bistatic ranges Rijk through different signal path combinations, each signal path combination from a feed element “i,” to an array element “j,” and to a feed element “k”. The measuring includes radiating energy from feed element “i”, and reflecting some of the radiated energy from array element “j” back to feed element k of the feed array. The measured bistatic ranges are processed to solve for the set of parameters. Another embodiment of a method is for measurement of multiple array elements of an array, and includes radiating energy from one or more array elements, reflecting some of the radiated energy from a set of reflector elements back to the array elements each reflector element having a variable phase shifter associated therewith, cycling each reflector element phase shifter through a range of phase shifter settings at a unique rate, processing the received signals to extract a phase of the reflected energy as received at each element; and using the extracted phase for each element to determine a relative location of each array element.	7
REFERENCE TO RELATED APPLICATION [0001] This application is a continuation-in-part of U.S. application Ser. No. 08/354,944, filed Dec. 13, 1994. This reference is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to compositions and methods for treating mammalian disease conditions that are debilitating, fatal, hereditary, degenerative and/or undesirable. More specifically, the present invention relates to the transplantation of normal, or genetically transduced, or cytocline-converted myogenic cells into malfunctioning, and/or degenerative tissues or organs. [0004] 2. Description of the Prior Art [0005] Myoblast Properties [0006] In mammals, myoblasts are the only cell type which divide extensively, migrate, fuse naturally to form syncytia, lose their major histocompatibility Class I (MHC 1) antigens soon after fusion, and develop to occupy 50% of the body weight in humans. These combined properties render myoblasts ideal for gene transfer and somatic cell therapy (SCT). Myoblast therapy is a combined SCT and gene therapy. [0007] Myoblast Therapy [0008] Although the role of myoblasts/satellite cells in myogenesis and muscle regeneration dated back to the early 1960s (Konigsberg, I. R., Science, 140:1273 (1963), Mauro, A. J., Biophys. Biochem. Cytol., 9:493-495 (1961)), their use in animal therapy was not reported until 1978 (Law, P. K., Exp. Neurol., 60:231-243 1978)). [0009] The first myoblast transfer therapy (MTT) on a Duchenne muscular dystrophy (DMD) boy on Feb. 15, 1990 marked the first clinical trial on human gene transfer. Its success was reported (Law, P. K. et al., Lancet, 336:114-115 (1990); Kolata, G. The New York Times, Sunday, (Jun. 3, 1990)). Unlike bone marrow transplant which strictly replaces genetically abnormal cells with normal ones, MTT actually inserts, through natural cell fusion, all the normal genes within the nuclei of the donor myoblasts into the dystrophic myofibers to repair them. In addition, donor myoblasts also fuse among themselves, forming genetically normal myofibers to replenish degenerated ones. Thus, full complements of normal genes are integrated, through a natural developmental process of regeneration, into the abnormal cells and into the abnormal organ. [0010] The US Patent Office issued to this inventor a patent (U.S. Pat. No. 5,130,141) entitled “Composition for and methods of treating muscle degeneration and weakness” on Jul. 14, 1992. [0011] In October, 1993, the Food and Drug Administration (FDA) officially began regulating somatic cell therapy (SCT) with a definition of “autologous, allogenic, or xenogeneic cells that have been propagated, expanded, selected, pharmacologically treated, or otherwise altered in biological characteristics ex vivo to be administered to humans and applicable to the prevention, treatment, cure, diagnosis, or mitigation of disease or injuries.” (Federal Register, 58:53248-53251 (1993)). [0012] MTT falls under the umbrella of SCT and myoblasts and its physical, genetic or chemical derivatives become potential biologics in the treatment of mammalian diseases. [0013] As of May 25, 1994 the FDA has granted permission for Cell Therapy Research Foundation (CTRF) to charge $63,806 per subject. CTRF is an non-profit 501 (c) (3) research foundation founded by the inventor in 1991. Authorization by the FDA for CTRF to recover costs from subjects of these clinical trials is extremely important to establish the scientific credibility MTT and CTRF deserve, quoting the Jun. 17, 1994 edition of the Memphis Health Care News, “Permission to bill for an Investigational product is granted rarely,” says FDA spokesman Monica Revelle, “Applicants must endure numerous procedures, and must have what looks like a viable product at the end of the rainbow. It's used mainly to support testing of promising technology by small companies.” This statement was made in regard to research at CTRF. [0014] At this time CTRF holds the first and only FDA-approved human clinical trial under an Investigational New Drug (IND) application on MTT. It is extremely important to realize that CTRF has been working closely with the FDA to establish criteria and policies in the approval process of this IND for genetic cell therapy. The use of viral vector mediated gene therapy on human neuromuscular diseases has not met FDA approval. [0015] Cell Therapy with Myoblasts [0016] The cell is the basic unit of all lives. It is that infinitely small entity which life is made of. With the immense wisdom and knowledge of the human race, we have not been able to produce a living cell from nonliving ingredients such as DNA, ions, and biochemicals. [0017] Cell Culture is the only method known to man for the replication of cells in vitro. With proper techniques and precautions, normal or transformed cells can be cultured in sufficient quantity to repair, and to replenish degenerates and wounds. [0018] Cell transplantation bridges the gap between in vitro and in vivo systems, and allows propagation of “new life” in degenerative tissues or organs of the living yet genetically defective or injured body. [0019] Cell fusion transfers all the normal genes within the nucleus like delivering a repair kit to the abnormal cell. It is important to recognize that, for proper installation and future operation, the software packaged in the chromosomes needs other cell organelles as hardware to operate. [0020] Correction of a gene defect occurs spontaneously at the cellular level after cell fusion. The natural integration, regulation and expression of the full complement of over 80,000 normal genes impart the normal phenotypes onto the heterokaryon. Protein(s) or factor(s) that were not produced by the host genome because of the genetic defect are now produced by the donor genome that is normal. Various cofactors derived from expression of the other genes corroborate to restore the normal phenotype. [0021] Gene Therapy with Myoblasts [0022] The use of myoblasts as gene transfer vehicles has been researched by this inventor extensively. In mammals, myoblasts are the only cell type which divide extensively, migrate, fuse naturally to form syncytia, lose MHC-1 antigens soon after fusion, and develop to occupy 50% of the body weight in humans. These combined properties render myoblasts ideal for gene transfer. [0023] Natural transduction of normal nuclei ensures orderly replacement of dystrophin and related proteins at the cellular level in DMD. This ideal gene transfer procedure is unique to muscle. After all, only myoblasts can fuse and only muscle fibers are multinucleated in the human body. By harnessing these intrinsic properties, MTT transfers all normal genes to effect genetic repair. Since donor myoblasts also fuse among themselves to form normal fibers in MTT, the muscles benefit from the addition of genetically normal cells as well. [0024] Myoblast Therapy is the Medicine of the Future [0025] Health is the well-being of all body cells. In hereditary or degenerative diseases, sick cells need repairing and dead cells need replacing for health maintenance. [0026] Cell culture is the only way to generate new, live cells that are capable of surviving, developing and functioning in the body after transplantation, replacing degenerated cells that are lost. [0027] Myoblasts are the only cells in the body capable of natural cell fusion. The latter allows the transfer of all of the normal genes into genetically defective cells to effect phenotypic repair through complementation. MTT on DMD is the first human gene therapy demonstrated to be safe and effective. The use of MTT to transfer any other genes and their promoters/enhancers to treat other forms of diseases is underway. Myoblasts are efficient, safe and universal gene transfer vehicles, being endogenous to the body. Since a foreign gene always exerts its effect on a cell, cell therapy will always be the common pathway to health. After all, cels are what life is made of. [0028] DMD: A Sample Disease [0029] DMD is a hereditary, degenerative, debilitating, fatal, and undesirable mammalian disease. It is characterized by progressive muscle degeneration and loss of strength. These symptoms begin at 3 years of age or younger and continue throughout the course of the disease. Debilitating and fatal, DMD affects 1 in 3300 live male births, and is the second most common lethal hereditary disease in humans. DMD individuals are typically wheelchair-bound by age 12, and 75% die before age 20. Pneumonia usually is the immediate cause of death, with underlying respiratory muscle degeneration and failure of DMD individuals to inhale sufficient oxygen and to expel lung infections. Cardiomyopathic symptoms develop by mid-adolescence in about 10% of the DMD population. By age 18, all DMD individuals develop cardiomyopathy, but cardiac failure is seldom the primary cause of death. [0030] Before 1950, over 80 chemicals were evaluated and 33 were reported as potentially beneficial (Milhorat, A. T., Medical Annals of the District of Columbia, 23:15 (1954)). None are currently being used (Wood, D. S., In: Kakulas, B. A. and Mastaglia, F. L., eds.: Pathogenesis and therapy of Duchenne and Becker muscular dystrophy. New York: Raven Press; 85-99 (1990)). Unconfirmed therapeutic benefits in DMD have been reported with vitamins, amino acids (Van Meter, J. R., Calif. Med., 79:297 (1953)), ATP (Nakahara, M., Arzneim. Forsch., 15:591 (1965)), coenzyme Q (Folkers, K. et al., Excerpta Med. Int. Congr. Ser., 334:158 (1974)), adenylosuccinic acid (Bonsett, C. A., Indiana Medicine, 79:236 (1986)) and growth hormone inhibitor (Coakley, J. H. et al., Lancet, 1 (8578): 184 (1988)). Several hundred drugs have been screened (Wood, supra), with some studies showing consistent benefits from steroids (Entrikin, R. K. et al., Muscle Nerve, 7:130-136 (1984)). [0031] The beneficial effects of prednisone on DMD was first reported almost 20 years ago (Drachman, D. B. et al., Lancet, 2:1409-1412 (1974)). The researchers reported that prednisone could delay the degenerative process and in some cases even transiently strengthen DMD muscles. The evidence substantiating prednisone is not without debate (see Munsat, T. L. and Walton, J. N., Lancet, 1:276-277 (1985); Rowland, L. P., Lancet, 1:277 (1975); and Siegel, I. M. et al., I.M.J., 145:32-33 (1974)). Although the mechanism(s) through which prednisone mediates its effect is undefined. Prednisone causes numerous side-effects, and prolonged use induces adverse reactions that by far out-weigh the questionable benefits reported. [0032] Gene manipulation and transfer are other approaches that are being used to treat hereditary and degenerative diseases. However, it will be quite some time before this type of treatment finds clinical application for DMD (Law, P. K., In: Kakulas, B. A. et al., eds.: Pathogenesis and therapy of Duchenne and Becker muscular dystrophy. New York: Raven Press, 190 (1990); and Watson, J. D. et al., Recombinant DNA. New York: W. H. Freeman and Co.; 576 (1992)). Success claimed over intramuscular DNA injections (Acsadi, G. et al., Nature, 352: 815-818 (1991); and Rolff, J. A. et al., Science 247:1465-1468 (1990)) and arterial delivery of immature muscle cells, also known as myoblasts, to skeletal muscle (Neumeyer, A. M. et al., Neurology, 42:2258-2262 (1992)) is very limited and questionable. Attempt of using transfected autologous myoblasts has resulted in low efficiency and mutation in transfection (Barr, E. and Leiden, J. M., Science, 254: 1507-1509 (1991); Dhawan, J. et al., Science, 254: 1509-1512 (1991); and Smith, B. F. et al., Mol. Cell. Biol., 10: 3268-3271 (1990)). Such approach will yield insufficient myogenic cells to provide for a whole body myoblast transfer therapy (MTT) to treat DMD patients (Law, supra). Clinical trials are currently underway for cystic fibrosis (CF) based on transgenic mice studies (Hyde, S. C. et al., Nature, 362: 250-255-(1993)). Clinical trials with gene therapy have also been attempted on severe combined immunodeficiency. (SCID). Unlike CF and SCID whose genetic defects are mediated through enzymic deficiencies, the genetic defect of DMD manifested as the absence of a structural protein called dystrophin in the cell membrane rather than a regulatory protein. [0033] Although dystrophin serves as a good genetic/biochemical marker (Hoffman, E. P. et al., Cell, 51: 919-928 (1987)) in the evaluation of muscle improvements, dystrophin replacement constitutes only part of the treatment process. This has already been demonstrated, among others, by the present inventor using MTT in mdx mice (Chen, M. et al., Cell Transplantation, 1:17-22 (1992); Karpati, G. et al., Am. J. Pathol., 135: 27-32 (1989); and Patridge, T. A., et al., Nature, 337:176-179 (1989)) and in humans (Gussoni, E., et al., Nature, 356: 435-438 (1992); Huard, J. et al., Clin. Sci., 81:287-288 (1991); Huard, J. et al., Muscle Nerve, 15:550-560 (1992); Law, P. K. et al., Lancet, 336:114-115 (1990); Law, P. K. et al., Acta Paediatr. Jpn., 33:206-215 (1991); Law, P. K. et al., Adv. Clin. Neurosci., 2:463-470 (1992); Law, P. K. et al., In: Angelini, C. et al., eds. Muscular dystrophy research. New York: Elsevier Science Publishers, 109-116 (1991); and Law, P. K. et al., Acta Cardiomiologica, 3:281-301 (1991)). Because DMD pathology is one of muscle degeneration and weakness, structural and especially functional improvements are of primary concern. These two parameters have been extensively studied using the dy 2J dy 2J dystrophic mouse as an animal model of hereditary muscle degeneration (Law, P. K., Exp. Neurol., 60:231-243 (1978); Law, P. K., Muscle Nerve, 5:619-627 (1982); Law, P. K. et al., Transplant Proc., 20:1114-1119 (1988); Law, P. K. et al., In: Griggs, R. C.; Karpati, G., eds. Myoblast Transfer Therapy. New: Plenum Press; 75-87 (1990); Law, P. K. et al., Muscle Nerve, 11:525-533 (1988); Law, P. K. et al., In: Kakulas, B. A.; Mastaglia, F. L., eds. Pathogenesis and therapy of Duchenne and Becker muscular dystrophy. New York: Raven. Press; 101-118 (1990); and Law, P. K. and Yap, J. L., Muscle Nerve, 2:356-363 (1979)). These studies lead to the first MTT clinical trial or single muscle treatment (SMT) (Gussoni, E. et al., Nature, 356:435-438 (1992); Huard, J. et al., Clin. Sci., 81:287-288 (1991); Huard, J. et al., Muscle Nerve, 15:550-560 (1992); Law, P. K. et al., Lancet, 336:114-115 (1990); Law, P. K. et al., Acta Paediatr. Jpn., 33:206-215 (1991); Law, P. K. et al., Adv. Clin. Neurosci., 2:463-470 (1992); Law, P. K. et al., In: Angelini, C. et al., eds. Muscular dystrophy research. New York: Elsevier Science Publishers: 109-116 (1991); and Law, P. K. et al., Acta Cardiomiologica 3:281-301 (1991)). [0034] The feasibility, safety, and efficacy of MTT were assessed by this inventor in experimental lower body treatments involving 32 DMD boys aged 6-14 years of age, half of whom were non-ambulatory (Law, P. K. et al., Cell Transplantation, 2; 485-505 (1993)). Through 48 injections, 5 billion (55.6×10 6 /mL) normal myoblasts were transferred into 22 major muscles in both lower limbs in each of the subjects. Result at 9 months after MTT indicated, interalia, that (1) MTT is a safe treatment; (2) MTT improves muscle function in DMD; and (3) more than 5 billion myoblasts are necessary to strengthen both lower limbs of a DMD boy between 6 and 14 years of age. [0035] Other Disease Conditions [0036] Potentially every genetic disease can be benefited by MTT. Through natural cell fusion, donor myoblasts insert full complement of normal genes into genetically abnormal cells to effect repair. Promoters and enhancers of the defective gene can be supplied or activated or repressed to achieve gene transcription and translation with the release of hormone(s) or enzyme(s) from transplanted myogenic cells. Likewise, structural protein(s) can be produced to prevent or to alleviate disease conditions. [0037] Alternatively transduced myoblasts can be used. The procedure consists of a) obtaining a muscle biopsy from the patient, b) transfecting a “seed” amount of satellite cells with the normal gene, c) confirming the myogenicity of the transfected cells, d) proliferating the transfected myoblasts to an amount enough to produce beneficial effect and e) administering the myoblasts into the patient. [0038] Retroviral vectors have been used to transfer genes into rat and dog myoblasts in primary cultures under conditions that permit the transfected myoblasts to differentiate into myotubes expressing the transferred genes (Smith, B. F. et al., Mol. Cell Biol., 10:3268-3271 (1990)). Furthermore, mice injected with murine myoblasts that are transfected with human growth hormone (hGH) show significant levels of hGH in both muscle and serum that are stable for 3 months (Dhawan, J. et al., Science, 254:1509-1512 (1991); Barr E. and J. M. Leiden, Science, 254:1507-1509 (1991)). [0039] The transduced myoblast transfer was inspired by a similar approach on adenosine deaminase (ADA) deficiency. In the latter situation, T cells from the patient were transfected with functional ADA genes and returned to the patient after expansion in the number of the transfected cells through cell culture (Culver, K. W. et al., Transpl. Proc., 23:170-171 (1991)). [0040] Similar approach has already been tested in animals using genetically transduced myoblasts to treat hemophilia B (Yao, S. N. et al., Gene Therapy, 1:99-107 (1994)), cardiomyopathy (Marelli, D., Cell Transplantation, 1:383-390 (1992); Koh, G. Y. et al., J. Clin. Inves., 92:1548-1554 (1993)), anemia (Hamamori, Y. et al., Human Gene Therapy, 5:1349-1356 (1994)). Undoubtedly, there will be many hereditary diseases to which myoblast therapy will apply. [0041] Although differentiated, myoblasts are nonetheless embryonic cells that are capable of de-differentiated or even converted. Thus, myoblasts have recently been shown to be converted into osteoblasts with bone morphogenetic protein-2 (Katagiri, T. et al., J. Cell Biol., 127:1755-1766 (1994)). This study demonstrates that cytocline-converted myoblasts can be administered to patients with bone/cartilage degenerative diseases. Alternatively, it has been demonstrated that mouse dermal fibroblasts can be converted to a myogenic lineage (Gibson, A. J. et al, J. Cell Sci., 108:207-214 (1995)). [0042] The implicated usage of myoblast transfer therapy to treat cancer and type II diabetes mellitus is described below. [0043] Why Myoblast Therapy [0044] In hereditary or degenerative diseases, gene defects cause cells to degenerate and die with time. An effective treatment must not only repair degenerating cells, but replenish dead cells as well. This can best be achieved by the transplantation of genetically normal cells, or somatic cell therapy. The advent of molecular genetics favors single gene manipulation which is currently being explored to treat genetic diseases. Like pharmaceuticals, single gene manipulation cannot replenish lost cells. Further, there is very limited evidence that these approaches can repair degenerating cells. [0045] In U.S. Pat. No. 5,130,141, this inventor disclosed for the first time compositions and methods for treating muscle degeneration and weakness. A composition comprised of genetically normal myoblasts from a donor was injected into one or more of the muscles of a host having a hereditary neuromuscular disorder. Muscle structure and function were greatly improved with the injection, thereby preventing or reducing muscle weakness which is a primary cause of crippling and respiratory failure in hereditary muscular dystrophies. This transplantation of genetically normal muscle cells into the diseased muscles of patients with hereditary muscular dystrophy is known as MTT. [0046] MTT differs significantly from the conventional single gene transfer format in several respects. In this latter gene therapy, single copies of the down-sized dystrophin gene are transduced as viral conjugates into the mature dystrophic myofibers in which many proteins, both structural and regulatory, are lost previously. Multiple gene insertion is necessary to replace these lost proteins (FIG. 1). More gene insertion is needed to produce the cofactors to regulate and to express these lost proteins in order to repair the degenerating cell. SUMMARY OF THE INVENTION [0047] The demonstration of preliminary feasibility, safety, and efficacy (Law et. al., Cell Transplantation, 2:485 (1993)) of myoblast transfer therapy MTT prompted this inventor to initiate a whole body trial (WBT) injecting 12.5 billion myoblasts into each of 64 Duchenne muscular dystrophy (DMD) boys and a boy with infantile facioscapulohumeral dystrophy (IFSH). The randomized double-blind clinical trial protocol, approved by the FDA (IND Phase II) and the Essex IRB involves two MTT procedures separated by 3 to 9 months. Each procedure delivers 200 injections or 12.5 billion myoblasts, to either 28 muscles in the upper body (UBT) or to 36 muscles in the lower body (LBT). Injected muscles include those in the neck, shoulder, back, chest, abdomen, arms, hips, and legs. Subjects take oral cyclosporine for 3 months after each MTT. One IFSH and 10 DMD boys have received WBT and 20 more DMD boys have received UBT or LBT in the past 17 months with no adverse reaction. These preliminary results indicate that the WBT is feasible and safe. While blinding will continue until the end of the study as to which side of the biceps brachii or quadriceps received myoblasts or placebo, five subjects have demonstrated immunocytochemical evidence of dystrophin in one of these muscle biopsies 3 to 9 months after MTT. The contralateral muscle biopsies show no dystrophin. The pulmonary function (FVC) either shows no deterioration, or has improved by 15 to 25% in over 80% of the subjects 3 to 6 month after MTT. About 50% of the subjects report behavioral improvement in running, balancing, climbing stairs and playing ball. One 14 yr-old DMD subject has stayed active without the need of a wheelchair after MTT (Law, P. K. et al., Amer Soc Neural Transpl Abst., p. 27 (1995); Law, P. K. et al., J. Cellular Biochem.Supp, 21A:367, (1995)). [0048] This demonstration of feasibility and safety in administering 30 billion myoblasts into a human subject provides the pivotal evidence that myoblasts can be used as a biologic to treat human diseases. The demonstration of the dosage effectiveness further confirms the idea that myoblast therapy can be used to treat a whole variety of mammalian diseases be it a hereditary, degenerative debilitating, fatal, or undesirable disease condition. [0049] The present invention provides compositions and methods for repairing degenerating cells and replenishing lost cells in patients with hereditary or degenerative diseases, in particular those characterized by muscle malfunction, degeneration and weakness. In practicing the present invention, any myogenic cell may be used, regardless of whether it is of skeletal, smooth, or cardiac in origin. Transferred cell types include myoblasts, myotubes and/or young muscle fibers. The myogenic cells may be primary-cultured or cloned from muscle biopsies of normal donors. They may also be cytocline converted or genetically transduced myogenic cells. Typically, the parents, siblings, or friends of the dystrophic patient are the donors. In addition, it is contemplated that the establishment of superior cell lines of myoblasts, whether from humans or animals, will provide a ready access of healthy donor cells for patients who do not otherwise have a suitable donor (FIG. 2 to 5 , also Law, P. K., Myoblast Transfer, Landes, Austin, (1994)). It is further contemplated that the cell transplantation procedure will augment size, shape, appearance or function, and/or alleviate the disease conditions. [0050] The present invention provides a method for controlling, initiating, or facilitating cell fusion once the myoblasts are injected into one or more of the muscles of a patient with the degenerative disease. By artificially increasing the concentration of the large chondroitin-6-sulfate proteoglycan (LC6SP) over the patient's endogenous level, fusion of the transferred donor myoblasts among themselves or with other cell types can be enhanced and controlled. (Law, P. K., Myoblast Transfer Landes, Austin (1994)). It is yet another object of the invention to improve the fusion rats between the host and donor cells. To this end, various injection methods were tested and compared including injecting diagonally through the myofibers, perpendicular to the myofiber surface, parallel to the myofibers, and at a single site into the muscle. The goal is to achieve maximum cell fusion with the least number of injections (FIGS. 6 to 8 , also Law, P. K., Myoblast Transfer, Landes Austin, (1994)). [0051] In a further embodiment, the technologies of in vitro fertilization and blastomere recombination can be used on known Duchenne carriers to increase their chances of having normal children (FIG. 9 to 13 ; also Law, P. K., Myoblast Transfer, Landes, Austin, (1994)). [0052] It is yet another object of the present invention to provide an automated cell processor, a highly efficient means for producing mass quantities (over 100 billion in one run) of viable, sterile, genetically normal as well as functional myogenic cells whether genetically transduced or cytocline-converted. The cell processor has an intake system which will hold biopsies of various human tissues. The cell processor's computer will be programmed to process tissue(s), and will control time, space, proportions of culture constituents and apparatus functions. Cell conditions can be monitored at any time during the process. The output system provides a supply of cells suitable for transfer in cell therapy or for shipment (FIGS. 14 to 15 ). [0053] It is yet another embodiment in which myoblasts, and/or their physical, genetic, chemical derivatives, are used to treat cancer. FIGS. 16 to 18 illustrate melanoma cancer cell death upon exposure to myoblasts in fusion medium. According to Cancer Prevention and Control edited by Greenwald, P., Kramer, B. S., and Weed, D. L. (Marcel Dekker, Inc. New York, 1995), skeletal muscles appear to be devoid of cancer, though malignant tumor and metastases are found in every other organ. The very few cases of sarcoma reported are rare exceptions. [0054] The recent immunocytochemical demonstration of dystrophin in DMD muscles 9 months after MTT indicated long term correction of genetic defect(s) can result from myoblast therapy (FIG. 19). This principle can apply to treat malfunctional insulin resistant muscles in Type II diabetes mellitus. As a universal gene transfer vehicle, donor myoblasts insert the whole normal genome and this can repair any malfunction of skeletal muscle cells, rendering them insulin sensitive (FIG. 20). [0055] Additional features and advantages are described in and will be apparent from the detailed description of the presently preferred embodiments and from the drawings. Further, all references described herein are incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS [0056] [0056]FIG. 1 is a diagram of some of the known protein defects in DMD muscle cells that differ from normal muscle cells. These include membrane structural proteins that are decreased or absent in DMD such as dystrophin (DIN), dystrophin-related-protein (DRP) and dystrophin-associated-glycoproteins (DAG), enzymes elevated in serum levels of DMD patients such as creatinine phosphokinase (CPK), aldolase (ALD) and aspartate transaminase (AST), and mitochondrial (Mito) protein differences. Although these protein defects are caused primarily or secondarily by the dystrophin gene defect, their correction will require multiple gene (G1 to G7) transfer. [0057] [0057]FIG. 2 illustrates MHC-negative myoblasts and MHC-positive myoblasts. (A) represents human myoblasts assayed with anti-MHC class I antibodies and viewed under fluorescent microscopy. The arrow indicates the MHC-negative myoblast. (B) is of the same slide viewed under a regular light microscope. The arrow indicates the MHC-negative myoblast. Bar=20 u [0058] [0058]FIG. 3 illustrates an analysis of myoblasts by cytofluorometry. Control: myoblasts reacted without anti-MHC class I antibodies. Samples: myoblasts reacted with anti-MHC class I antibodies. [0059] [0059]FIG. 4 is a scatter diagram of the separation of the myoblasts that were negative for MHC-I antigen expression by cytofluorometry. [0060] [0060]FIG. 5 illustrates fluorescent intensities of two groups of myoblasts after separation by cytofluorometry. (A) represents MHC-positive myoblasts. (B) represents MHC-negative or weakly expressed myoblasts. (A) and (B) are of the same magnification and the pictures were similarly processed. Bar=30 um. [0061] [0061]FIG. 6 illustrates the angle of injection that determines myoblast distribution. (A) Oblique myoblast injection delivers donor myoblasts to the greatest number and area of recipient muscle fibers with the least leakage, resulting in the formation of the most mosaic fibers. (B) Transverse injection delivers donor myoblasts to a large number of fibers, but covers a smaller area and is more likely to result in leakage from the injection. (C) Longitudinal injection results in donor myoblasts fusing with each other, with fewer mosaic fibers being formed. (D) Focal injection results in only a small area of a few recipient muscle fibers being injected with donor myoblasts. [0062] [0062]FIG. 7 illustrates donor myoblast nuclei labeled with fluoro-gold (FG), and are present in host muscle at seven days after MTT. (A) Mosaic myofiber with donor and recipient nuclei (black arrow) and donor myotube with donor myonuclei (white arrow). (B) Mosaic myofibers with donor (white arrows) and recipient (black arrows) nuclei. [0063] [0063]FIG. 8 illustrates distributions of donor myoblasts labeled with FG in host muscle. Even distribution of donor myoblasts can be achieved with oblique myoblast injection (A,B), or donor nuclei may appear in patches (C,D, white arrows) which gradually show more abnormal nuclei and debris. (C) represents a transverse injection and (D) a longitudinal injection. [0064] [0064]FIG. 9 illustrates the production of allophenic twins with the mechanism of allophene formation. [0065] [0065]FIG. 10 illustrates three littermates: 1 normal, 1 allophene, 1 dystrophic (top to bottom). [0066] [0066]FIG. 11 illustrates physiological recordings of maximal isometric twitch and tetanus tensions at 80 Hz elicited from the soleus muscles of the normal, allophenic, and dystrophic littermates. The allophene recordings resemble the normal, rather than the dystrophic recordings. [0067] [0067]FIG. 12 illustrates soleus cross-sections from allophenic mice demonstrating core fibers (arrows) characteristic of muscle from DMD carriers. Whereas most myofibers remain normal in appearance, some degenerative characteristics such as fiber splitting and central nucleation are apparent. [0068] [0068]FIG. 13 further illustrates soleus cross-sections from allophenic mice demonstrating core fibers (arrows) characteristic of muscle from DMD carriers. Although most myofibers remain normal in appearance, some degenerative characteristics are visible such as fiber splitting and central nucleation. [0069] [0069]FIG. 14 illustrates the general layout of an automated cell processor. [0070] [0070]FIG. 15 illustrates the detailed design of culture and harvest automated actions. [0071] [0071]FIG. 16 is a comparison of cancer cell growth media with myoblast growth media on cultured melanoma (CRL6322) cells. (A, C, E, G) low magnification; (B, D, F, H) high magnification. (A, B) Melanoma cells cultured in cancer cell growth media for 9 days appear healthy, as evidenced by their numbers, elongated shapes, and branching processes. (C, D) Similar amount of melanoma cells seeded and cultured in myoblast growth media for 9 days are more numerous and differentiated. (E, F) After 14 days in cancer cell growth media, the melanoma cells, while numerous, have become spherical in shape and detached from the surface, indicating that the cells are dead (E). At higher magnification only a few healthy cells remain (F). (G, H) After 14 days in myoblast growth media, the melanoma cells still appear numerous and healthy. [0072] [0072]FIG. 17 illustrates myoblasts and melanoma cells (2:1 concentration ratio) co-cultured in myoblast growth media. (A, C) low magnification; (B, D) high magnification. (A, B) After 9 days in culture myoblasts and melanoma cells are numerous and remain differentiated. (C, D) After 14 days in culture myoblasts dominate the culture, with melanoma cells still surviving. [0073] [0073]FIG. 18 illustrates myoblasts and melanoma cells co-cultured in myoblast growth medium for 4 days and then in myoblast fusion medium. (A, C, E, G) low magnification; (B, D, F, H) high magnification. (A, B) Myoblasts and melanoma cells (1:1 concentration ratio) after 5 days in myoblast fusion medium. Many melanoma cells have become spherical and detached from the surface and are not surviving in this medium. Myoblasts remain healthy and are beginning to fuse. (C, D) Myoblasts and melanoma cells (1:1 concentration ratio) after 10 days in myoblast fusion medium show numerous dying cells. Only a few can survive in this medium for this long, and they are detached and dying (D). (E, F) Myoblasts and melanoma cells (1:1 concentration ratio) after 19 days in myoblast fusion media. The surviving myobalasts retain their spindle shape and align with each other. Melanoma cells have become spherical and detached. (G, H) Myoblasts and melanoma cells (3:1 concentration ratio) after 19 days in myoblast fusion medium. Myoblasts have begun to fuse, forming myotubes. [0074] [0074]FIG. 19 is an immunocytochemical demonstration of dystrophin human muscle. Sarcolemm localization of dystrophin is shown in normal control muscle (A) but not in DMD muscle (B). (C, D) DMD biceps brachii muscles from a subject who received MTT in one biceps and placebo injections in the contralateral muscle 9 mo before biopsies. Since blinding continues until the end of the study, the designation of the MTT muscle cannot be revealed. However, only one muscle shows sarcolemmal localization of dystrophin. (B), (C), and (D) were intentionally over-exposed to show immuno-reactive background elements not associated with the sarcolemma. [0075] [0075]FIG. 20 illustrates (a) normal skeletal muscle metabolizing glucose with insulin. (b) In Type II diabetes mellitus, the major sequela of insulin resistance is decreased muscle uptake of glucose. It is possible that the glucose transporter in muscle is abnormal. It is known that insulin-mediated stimulation of tyrosine kinase and autophosporylation are impaired. These latter defects can be corrected by MTT by normal gene expression (from Metabolism 6:6, 1993). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0076] The compositions and methods described herein will be illustrated for the treatment of individuals having hereditary neuromuscular diseases. However, it is contemplated that other hosts and other disease states may be treated with the inventive compositions and methods. [0077] A. Controlled Cell Fusion [0078] Myoblasts have the unique ability to fuse with other cells. With the use of normal myoblasts, a full complement of normal genes can be introduced into any genetically abnormal cells through cell fusion. For example, the genetically abnormal cell could be a liver cell, heart muscle cell, or even a brain cell. The idea is to introduce a full complement of normal genes into abnormal cells and, therefore, treat the genetic disease at the gene level and not at the hormonal or biochemical level. [0079] For treating genetic diseases that involve structural protein abnormalities rather than regulatory protein abnormalities, it would be useful to control, initiate or facilitate cell fusion once myoblasts were injected into the body. It is known that myoblasts fuse readily at low serum concentrations in culture. The process is more complex in the in vivo situation. As the myoblasts are injected intramuscularly into the extracellular matrix (ECM), injection trauma causes the release of basic fibroblast growth factor (bFGF) and large chondroitin-6-sulfate proteoglycan (LC6SP) (Young, H. E., et al., J. Morph., 201:85-103 (1989)). These latter growth factors stimulate myoblasts proliferation. Unfortunately, they also stimulate the proliferation of fibroblasts that are already present in increased amounts in the dystrophic muscle. It is, therefore, necessary to inject as pure as possible fractions of myoblasts in MTT without contaminating fibroblasts. [0080] Controlled cell fusion can be achieved by artificially increasing the local concentration of LC6SP over the endogenous level at the transfer site. In muscles, this is achieved by including approximately 5 μM of LC6SP in the transfer medium. In addition, insulin facilitates the developmental process in vitro, and may result in the formation of myotubes soon after myoblast injections. The use of LC6SP (ranging from approximately 5 μM to about 5 mM) in the transfer medium will likely lead to greater MTT success. [0081] B. Myoblasts: The Universal Gene Transfer Vehicles Whereas MTT results in the formation of genetic mosaicism with gene transfer occurring in vivo, the production of heterokaryons in vitro has immense medical application. This can be achieved by controlled cell fusion with myoblasts. [0082] This research relates to the in culturo transfer of the normal nuclei with all of their normal genes from donor myoblasts into the genetically normal and/or abnormal cells, e.g. the cardiomyocytes. This development is especially important considering that cardiomyopathic symptoms develop in mid-adolescence in about 10% of the DMD population. By age 18, all DMD individuals develop cardiomyopathy. Undoubtedly, the ability to replenish degenerated and degenerating cardiomyocytes will have an immense impact on heart diseases even in the normal population where there is a great shortage of hearts for transplantation. [0083] Normal cardiomyocytes have a very limited ability to proliferate in vivo or in vitro. The heart muscles damaged in heart attacks or in hereditary cardiomyopathy cannot repair themselves through regeneration. By integrating the skeletal muscle cell characteristic, mitosis, heterkaryotic cardiomyocytes will be able to proliferate in vitro. [0084] Controlled cell fusion between normal myoblasts and normal cardiomyocytes may result in heterokaryons exhibiting the characteristics of both parental myogenic cell types. Clones can be selected based on their abilities to undergo mitosis in vitro to develop desmosomes, gap junctions, and to contract strongly in synchrony after cell transplantation. [0085] These genetically superior cells can then be delivered through catheter pathways of the type described by Jackman W M, et al. (In: Zipes D P, and Jalife J, eds. Cardiac electrophysiology. From Cell to Bedside. Philadelphia: W B Saunders Company, 491-502, (1990)) after mapping of the injured sites. With the ability to grow large quantity of these cardiomyocytes, the correction of structural, electrical and contractile abnormalities in cardiomyopathy can be tested first in dystrophic, cardiomyopathic hamsters and then in humans. [0086] The genetic transfer of the mitotic property of myoblasts onto cardiomyocytes with in vitro controlled cell fusion enables the resulting heterokaryotic cardiomyocytes to multiply, yielding enough numbers of cells for the cell transplant to be effective. [0087] Recently, it was reported that fetal mouse cardiomyocytes grafted into the myocardium of syngeneic hosts formed nascent intercalated disks between host and donor cells (Soonpaa M H, et al., Science, 264:98-(1994)). The use of fetal cells for cell transplant has and will continue to raise ethical questions. The fact still remains that fetal cells will not produce enough cardiomyocytes to mend a myocardial infarct. The bioengineering of mitotic cardiomyocytes using myoblasts provides a solution to the problem in view of reported studies that recombinant genes introduced into cardiomyocytes are expressed for at least 6 months, and appear to be regulated normally by humoral signals. [0088] Whereas myoblast transfer into the dystrophic myocardium followed by in vivo controlled cell fusion may provide a structural impediment at the infarct, it remains to be shown that the myoblasts will integrate well with the cardiomyocytes, considering that the pumping action of the heart will disaggregate the developing cells from the host myocardium. [0089] C. Cosmetic Usage [0090] In a broader sense, the cell therapy concept can significantly contribute to the field of plastic surgery. With cell therapy, implantation of silicone could be avoided. The use of myoblasts and/or fat cells could be used in a much more natural way to replace silicone injections for facial, breast and hip augmentation. Modified adipose tissue involving mixing and/or hybridization of myoblasts and fat cells can be used to control size, shape and consistency of body parts. Since muscle cells do not break down as easily as fat cells, good results may be long-lasting. Today, body builders are in search of increasing muscle mass and function at the right places. The use of myoblast transfer to boost muscle mass is a natural solution. [0091] D. Superior Cell Lines [0092] The establishment of superior cell lines of myoblasts is a high-risk challenge, but its benefits are numerous. These cell lines should be highly myogenic, nontumorigenic, nonantigenic, and will develop very strong muscles. [0093] A unique property of myoblasts is their loss of major histocompatibility complex class I (MHC-I) surface antigens soon after they fuse. This has important implications in the usage of an immunosuppressant after myoblast transfer therapy. (See Huard J, et al., Muscle Nerve, 17:224-34 (1994); Roy R, et al., Transpl Proc, 25:995-7 (1993); and Huard J, et al. Transpl Proc, 24:3049-51 (1992)). The immunosuppression period depends on how soon the myoblasts lose their MHC-I antigens after MTT. Even more ideal is the establishment of a myoblast cell line in which MHC-I antigens are absent, thereby allowing MTT without immunosuppression. [0094] In our study, human myoblasts were cultured from normal muscle biopsies in accordance with the methods disclosed in Law, P. K., et al., Cell Transplantation, 1:235 (1992) and Law, P. K., et al., Cell Transplantation, 2:485 (1993). The MHC-I antigens expressed on the myoblasts were demonstrated with fluorescent immunoassay. Cell cycle synchronization of myoblasts was carried out by adding colchicin in the growth medium and incubating for 48 hours. The myoblast preparations used in the experiment were 98% pure as assessed by immunostaining with the monoclonal antibody (MAb) anti-Leu-19. [0095] Myoblasts were incubated with anti-MHC-I MAb (mouse 1:25 dilution, Silenus Lab, Australia) at room temperature. After washing, the myoblasts were incubated with FITC conjugated anti-mouse-IgG (Sigma) for 45 minutes and examined under fluorescence microscope with wide band ultraviolet (UV) excitation filter. Cytofluorometry was performed with a Be on-Dickinson cell sorter operated at 488 mM. Myoblast control was carried out by omitting the first antibodies in the immunoassay as the background of autofluorescence. [0096] 91.7% of the myoblasts reacted with MHC-I MAb. The reactions ranged from strong to weak. The remaining 8.3% of the myoblasts were negative for MHC-I antigen expression. FIG. 2 illustrates both MHC-negative myoblasts and MHC-positive myoblasts. The MHC-negative myoblasts were successfully separated by cytofluorometry, which is illustrated in FIGS. 3, 4. Both groups of myoblasts were then cultured for three weeks without significant difference in proliferation. [0097] The lack of MHC-I antigens on these myoblasts may enhance survival of these myoblasts in recipients after MTT. FIG. 5 illustrates the fluorescent intensities of both MHC-positive myoblasts and MHC-negative or weakly expressed myoblasts after separation by cytofluorometry. [0098] The immunosuppressant, cyclosporine, has many side effects and by suppressing the immune system, allows infection to prevail. Myoblasts without MHC-I antigen expression may contribute to a new cell line more capable of surviving in the host than the regular myoblasts. This superior cell line will eliminate the need to use the immunosuppressant, and will provide a ready access for patients who do not have a donor. [0099] These superior cell lines have to be derived from clones of primary myoblast cultures because they are selected for their unique properties. Unfortunately, it has been shown that all clones of myoblasts eventually produce tumors if allowed to proliferate excessively. Thus, these cell lines should not be allowed to proliferate over 30 generations. [0100] E. Myoblast Injection Methods [0101] Aside from donor cell survival in an immunologically hostile host, cell fusion is the key to strengthening dystrophic muscles with MTT. To improve the fusion rate between host and donor cells, various injection methods aimed at wide dissemination of donor myoblasts were tested and compared. These included injecting diagonally through the myofibers, perpendicular to the myofiber surface, parallel to the myofibers, and at a single site into the muscle. FIG. 6 illustrates myoblast distribution as a function of the angle of the injection. The goal was to achieve maximum cell fusion with the least number of injections. [0102] Fluoro-gold (FG, 0.01%) labeled human or mouse (C57BL/6J-gpi-lc/c) myoblasts (0.05 ml of a 10 5 cells/ml solution) were injected into the gastrocnemius muscles of twenty normal 3-month old normal mice (C57BL/6J-gpi-lb/b). Host mice were immunosuppressed with a daily subcutaneous injection of cyclosporine at 50 mg/kg body weight. Groups of mice were sacrificed on day 7, 14, 24, 34, and 44 after cell injection. Transverse. sections of injected muscles were examined with fluorescence microscopy. The cell fusion rates were estimated by calculating the percentage of host muscle fibers bearing donor nuclei out of the total number of muscle fibers in the area of donor cell covered. The glucose phosphate isomerases (GPI) of the injected muscles were also examined with agarose gel electrophoresis (200 V anode to cathode, 3 hours, pH 8.6). The first appearance of mosaic myofibers in the tissue sections was within seven days after cell injection. This is illustrated in FIG. 7. The highest fusion rate achieved was 72.2%. The electrophoreograms of GPI showed host donor and mosaic GPI in muscle specimens at least up to 44 days after MTT. Myoblasts injected obliquely through the myofibers were widely and evenly distributed with ejection of the myoblasts as the needle is withdrawn. This is shown in FIG. 8. Myoblasts injected perpendicular to the myofibers were partially distributed, while myoblasts that were injected longitudinally through the core of the muscles and parallel to the myofibers were poorly distributed. Similarly, injection at one spot gave poor distribution and fusion. Considering that a small volume of a concentrated solution causes less muscle damage than a larger volume of a relatively less concentrated solution, and in view of the trauma caused by injection decreases the regenerative capability of dystrophic muscles, the technique of myoblast delivery is essential for MTT success. [0103] Although oblique injection has been used in our clinical trials, there is room for improvement since human muscles are larger and the myofiber orientation of different muscle groups have to be well-studied by the orthopedic surgeons who administer myoblast injections. Judging from previous mouse studies, 20% normal myonuclei were able to maintain normal phenotype in dystrophic myofibers. [0104] F. Exercise and Physical Therapy [0105] Strenuous exercise causes damage to dystrophic myofibers. Lack of dystrophin causes the vulnerable sarcolemma to tear upon contraction. Other cell types are somewhat spared from degeneration because they do not contract. Thus, body building is counter-productive in DMD patients to compensate for loss of muscle mass and strength. [0106] The use of exercise, however, in relation to MTT has not been studied. In dystrophic animals, it is well known that exercise hastens the degeneration of myofibers and thus aggravates the dystrophic condition, that is with dystrophic muscle fibers alone. The situation is different from MTT in which an attempt is made to produce a mosaic muscle containing normal, mosaic, and dystrophic fibers. The essence of MTT is to reconstruct the genetics and improve the phenotypes of dystrophic muscles. Thus, intensive exercise may induce the release of host satellite cells that will fuse with normal myoblasts to produce mosaic fibers. Undoubtedly, such dystrophic degeneration will induce normal muscle generation. Implanted myoblasts not only fuse to the newly sealed regions of damaged myofibers, but also survive as satellite cells. Mild exercise done shortly after MTT can be designed to facilitate myoblast mixing, alignment, and fusion, and to provide physical therapy to the newly formed fibers. Moderate exercise after innervation of newly formed fibers is likely to enhance the development of normal and mosaic fibers. Disuse plays a major role in the continued deterioration of dystrophic muscles, and physical therapy is prescribed for dystrophic patients. Disuse or lack of cross-bridge interaction results in a decrease of calcium binding. As a result, the excessive intracellular calcium promotes muscle damage in dystrophic muscles. [0107] G. Myotube Transfer [0108] In the later stages of DMD, there remains fewer myofibers to be repaired with MTT. Formation of new fibers to replenish degenerated cells is further complicated by the presence of excessive connective and fat tissues. While it takes approximately 1 to 3 weeks for donor myonuclei to be incorporated into dystrophic fibers for repair, it takes over 4 months for donor myoblasts to develop into mature normal fibers de novo to replenish lost cells. Meanwhile, the impediment to developing myotubes to be vascularized, innervated, and connected to tendons all threaten their survival. Enough nutrients have to be present for the developing fibers to lay down the contractile filaments myosin and actin. Neither electrical nor contractile activity is normal for the development of the fibers. This is the time when myotube transfer may be of help. [0109] Transplants of newborn normal muscles or myotubes into dy 2J dy 2J dystrophic mouse muscles have been shown by this inventor to produce normal muscle function and structure. (See Law, P. K. and Yap, J. L., Muscle Nerve, 2:356-63 (1979)). Myotubes are easily obtained in culturo through natural myoblast fusion by exposing confluent cultures to the fusion medium. In fact, small muscles have been produced with spontaneously contracting fibers in culture. The young fibers exhibit sarcomeres and immunostain positively for myosin. [0110] Myotube transfer can be administered through injection with larger gauge needles. Better still, they can be surgically implanted into the beds of fat and connective tissues dissected and removed by surgeons. Since muscles can develop great forces and scar tissues are inert, the developing muscles will force the scar tissues aside throughout their existence. [0111] Myotube transfer provides bioengineered young fibers in vitro. These fibers have lost their MHC-I surface antigens and are thus nonantigenic. Myotube transfer will not need to be administered with cyclosporin. For patients previously infected with cytomegalovirus (CMV), or other viruses, myotube transfer will be the choice. [0112] In addition, for autosomal dominant diseases such as facioscapulohumeral dystrophy (FSH), myotonia congenita, myotonia dystrophica and certain forms of congenital muscular dystrophy and limb-girdle dystrophy, formation of mosaic fibers may not be useful since nuclear complementation may not be effective. The use of entirely normal myotubes through myotube transfer will undoubtedly open new avenues for treatment. [0113] H. Allophenic Mice [0114] Allophenic mice or mouse chimaeras are mice mosaics with two or more genotypes. They are produced by blastomere recombination (see Hogan B., et al. Manipulating the Mouse Embryo. A Laboratory Manual, Cold Spring Harbor Laboratory, (1986)) or by the artificial aggregation of embryos from two different strains of mice. In addition to being important specimens to study the clonal origins of somites and their muscle derivatives, allophenic mice have been shown by this inventor and others to demonstrate dystrophy suppression in natural development when genetically normal and dystrophic myogenesis coexist. [0115] By aggregating half embryos of normal (129 strain) and dystrophic (C57BL/6J dy 2J dy 2J strain) mice as shown in the diagram of FIG. 9, sets of allophenic twins were produced consisting of chimaeric mice and their normal and dystrophic littermates (FIG. 10). Although the dystrophic gene was present in the muscle fibers according to genotype marker analyses, these allophenic mice showed normal behavior, life span, and essentially normal muscle function shown in FIG. 11 and structure in FIGS. 12 and 13. [0116] Muscle fibers of these allophenic mice highly resemble those of the Duchenne female carriers. Whereas the dystrophic soleus contains 70% or more degenerating fibers, only 3 to 5% of the allophenic soleus fibers are abnormal. Many of these abnormal fibers showed “cores” as seen in the Duchenne carriers. Through natural cell fusion, normal myoblasts fuse with dystrophic ones to form mosaic myotubes that develop into phenotypically normal fibers. [0117] I. Normal Child for a Duchenne Carrier [0118] Conceivably the technology of in vitro fertilization and blastomere recombination used in the allophenic mouse studies can be applied to human. Known carriers may thus have better chances of bearing normal children. [0119] Accordingly, ova from a carrier and from a normal female can be obtained and fertilized in vitro with sperm recovered from the carrier's husband. The fertilized egg of the carrier has a 50/50 chance of being normal or dystrophic. Regardless of its genotype, its mixing with the normal fertilized egg will ensure the development of a normal phenotype. After culturing the embryo into the blastocyst stage, it can be implanted into the uterus of the carrier. The latter can be induced to be pseudo-pregnant with human gonadotrophin, thus allowing easy implantaion. [0120] The use of in vitro fertilization protects the mother. Abnormal developing embryos after blastomere recombination can be discarded. Furthermore, no blastomere needs to be removed for genetic analysis. [0121] Since the fertilized egg of the carrier has 50% chance of being normal, a PCR analysis for dystrophin messenger RNA can be conducted on blastomeres removed from the embryo at the blastocyst stage. Unfortunately, this risks damaging the embryo by removing part of it at an early developmental stage. [0122] J. Automated Cell Processors [0123] With the great demand for normal myoblasts, myotubes and young muscles, the labor intensiveness and high cost of cell culturing, harvesting and packaging, and the fallibility of human imprecision, an automated cell processor is needed. Such a processor would be capable. of producing mass quantities, over 100 billion per run, of viable, sterile, genetically well-defined and functionally demonstrated biologics, for example, myogenic cells. [0124] The automated cell processor will be one of the most important offspring of modern day computer science, mechanical engineering and cytogenetics (FIG. 14). The intakes will be for the biopsies of various human tissues. The computer will be programmed to process tissue(s), with precision control in time, space, and proportions of culture ingredients and apparatus maneuvers. Cell conditions can be monitored at any time during the process, and flexibility is built-in to allow changes. Different protocols can be programmed into the software for culturing, controlled cell fusion, harvesting and packaging. The outputs will supply cells, which will be ready for shipment or for injection using cell therapy. The automated cell processor will be self-contained in a sterile enclosure large enough to house the hardware in which cells are cultured and manipulated (FIG. 15). [0125] This inventor has developed a transfer medium that can sustain the survival and myogenicity of packaged myoblasts for up to 3 days at room temperature. Survival up to 7 days can be achieved when the myoblasts are refrigerated. This will allow the cell packages to be delivered to remote points of utilization around the world. [0126] The automated cell processor will simply replace current bulky inefficient culture equipment and elaborate manpower. Its contribution to human healthcare will undoubtedly be significant, and the manufacturing costs are expected to be relatively low. [0127] K. Cell Banks [0128] The automated cell processors will constitute only a part of cell banks. Ideally, donor muscle biopsies can be obtained from young adults aged 8 to 22 to feed the inputs of the automated cell processor. This will depend on the availability of healthy volunteer donors. Each donor has to undergo a battery of tests that are time-consuming and expensive. Based on the test results and the donor's physical condition, one can determine if the donor cells are genetically defective or infected with viruses and/or bacteria. These are the advantages of biopsies of mature tissues from adults. The major disadvantage, however, is that mature cells often do not divide, and even if they do, there is a limited number of generations that can propagate before becoming tumorigenic or nonmitotic. [0129] Human fetal tissues can potentially provide unlimited supplies of dividing cells. However, aside from ethical issues, it is difficult to determine the genetic normality of these cells, notwithstanding the existence of polymerase chain reaction (PCR) which is used to screen many human genetic diseases. [0130] As for the muscular dystrophies, the use of muscle primordia on fetal calves derived from in vitro fertilization of genetically well-defined background may be an alternative. Sperms and ova can be recovered from inbred strains of cattles that are known for their muscle strength and mass. In vitro fertilization will be followed by embryo culture and implantation into the uteruses of pseudo-pregnant cows. The fetuses are removed by Sicilian sections at specific developmental stages of the embryos. The muscle primordia that are rich in myoblasts can then be dissected out to feed into the automated cell processors. [0131] Transplantation of cattle cells into humans constitutes xenografting. Due to the significant differences between the human and the cattle immune systems, these xenografts will likely survive, develop and function in the recipients without the need for immunosuppressants. However, the method will be tested with and without immunosuppressants. [0132] L. Myoblast Derivatives vs. Cancer [0133] Evolution is one continual experiment through ages with numerous statistics. The near absence of cancer metastases in skeletal muscles suggests that the physical, electrical, mechanical or chemical presence of myogenic cells and derivatives prevents or annihilates cancer. [0134] In our study we showed that the physical and biochemical conditions of myoblast at the cell fusion stage caused the death of melanoma cancer cells (FIG. 16 to 18 ). This does not preclude the potential effect of similar or different conditions, including electrical and mechanical, of other myogenic cells at different developmental stages. [0135] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention all without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the appended claims.	Compositions and methods of treating mammalian diseases using myoblasts, and/or their physical, genetic, chemical derivatives. Myogenic cells that are normal, or genetically or phenotypically altered are cultured and transplanted into malfunctioning and/or degenerative tissues or organs to alleviate conditions that are hereditary, degenerative, debilitating, undesirable, and/or fatal. Treatment of these conditions is not limited to the usage of mechanical, electrical or physical properties of these myogenic cells, but includes the usage of biochemicals secreted/released by the latter. The present invention discloses the use of normal myoblasts to deliver the complete normal genome to effect genetic repair, or to augment the size, or the function of tissues or organs. Certain conditions may be better served with genetically altered myogenic cells derived from gene transduction, whereas others may be better served with cytoclimes converter cells. Endogenous biochemical(s) are used to control cell fusion of myoblasts among themselves or with other cell types. An automated cell processor within a cell bank which enables the manufacture, at a single run, of unprecedented large quantities (greater than 100 billion) of normal or genotypically or phenotypically altered myogenic cells is also disclosed.	2
FIELD OF THE INVENTION [0001] The present invention relates generally to the field of circulatory valve repair. More particularly, the present invention relates to the field of the repair of heart valves and specifically for the repair of mitral heart valves, for patients suffering from mitral regurgitation. BACKGROUND OF THE INVENTION [0002] There are four valves in the heart that serve to direct the flow of blood through the two sides of the heart in a forward direction. On the left side, the mitral and aortic valves direct oxygenated blood coming from the lungs, through the left side of the heart, into the aorta for distribution to the body. On the right side, the tricuspid valve, located between the right atrium and the right ventricle, and the pulmonary valve, located between the right ventricle and the pulmonary artery, direct de-oxygenated blood coming from the body, through the right side of the heart, into the pulmonary artery for distribution to the lungs. The anatomy of the heart and the structure and terminology of heart valves are described and illustrated in detail in numerous reference works on anatomy and cardiac surgery, including standard texts such as Surgery of the Chest (Sabiston and Spencer, eds., Saunders Publ., Philadelphia) and Cardiac Surgery by Kirklin and Barrett-Boyes, Pathology and Abnormalities of Heart Valves, incorporated herein by reference. [0003] All four heart valves are passive structures in that they do not themselves expend any energy and do not perform any active contractile function. They consist of moveable “leaflets” that are designed simply to open and close in response to differential pressures on either side of the valve. The mitral valve has two leaflets and the triscupid valve has three. The aortic and pulmonary valves are referred to as “semilunar valves” because of the unique appearance of their leaflets, which are most aptly termed “cusps” and are shaped somewhat like a half-moon. The components of the mitral valve assembly include the mitral valve annulus; the anterior leaflet; the posterior leaflet; two papillary muscles which are attached at their bases to the interior surface of the left ventricular wall; and multiple chordae tendineae, which couple the mitral valve leaflets to the papillary muscles. [0004] The problems that can develop with valves can be classified into two categories: (1) stenosis, in which a valve does not open properly, or (2) insufficiency, or regurgitation, in which a valve does not close properly. [0005] Mitral regurgitation (“MR”) is caused by dysfunction of the mitral subvalvular apparatus or direct injury to the valve leaflets. Multiple etiologies can lead to mitral regurgitation, with myxomatous degeneration of the valve and ischemic heart disease accounting for close to 60% of cases. Repair of the diseased valve requires major surgery on cardiopulmonary bypass to allow access to the valve. Consequently, some patients in the early or late stages of the disease are not considered appropriate candidates due to the high risk associated with the operation. Multiple studies have demonstrated that prosthetic replacement of the mitral valve can lead to significant postoperative left ventricular dysfunction and often requires lifelong treatment with anticoagulants. Mitral valve repair, using a posterior annuloplasty ring, has demonstrated improved results with better ventricular recovery. Nevertheless, recent studies performed by the inventors (Umana et al., Surg Forum 1997) have revealed that posterior ring annuloplasty causes changes in ventricular geometry that lead to paradoxical movement of the normal papillary muscles, further deteriorating ventricular performance. In contrast, the “bow-tie” repair in which the anterior and posterior leaflets of the mitral valve are fixed in opposition appears to enhance annular contractility while preserving ventricular architecture. This has resulted in improved postoperative ventricular function almost uniformly. [0006] The present invention addresses the needs of all patients with mitral regurgitation without mitral stenosis, including those who heretofore may have been excluded due to having only moderate MR or being too sick to be candidates for major surgery. [0007] The present invention finds utility not only for the repair of mitral valves but for all valves of the circulatory system, including aortic valves, tricuspid valves, and venous valves. [0008] Techniques for improving the efficacy of corporeal valves are known. For example, Laufer et al., U.S. Pat. No. 5,609,598 describes a valving system for treatment of chronic venous insufficiency. The system has inherent limitations in terms of its effectiveness for the procedure described and its applicability, if any, to other valves, especially cardiac valves. SUMMARY OF THE INVENTION [0009] The present invention is directed to a method and apparatus for use in heart valve repair involving the use of an inserted device or grasper for grabbing and clasping together the anterior and posterior leaflets of the valve, by insertion into the left ventricle through the right chest via a thorascope, through the jugular vein, or through the femoral artery. The grasper will grab both leaflets, preferably after the heart has been stopped or slowed pharmacologically. The correctness of the initial grasp is assessed by, for example, intraoperative echocardiography, to ensure, for example, in the case of the mitral valve, that the mitral regurgitation is resolved. If not, the grasper will be able to “adjust” the leaflets to allow better coaptation or, if needed, re-grab the leaflets in a different location. [0010] Either inherent to the grasper, as an integrally attached component or as a separate device, a fastening device is introduced and a fastener is deployed to securely hold the leaflets in place after the grasper has been released. The remaining portion of the device, or optionally any separate device, is then removed. [0011] Accessory devices needed for the procedure include instruments for thoracoscopic or percutaneous approaches. While the preferred method and apparatus described hereinbelow is discussed with reference to its use in connection with mitral valve repair, it is contemplated that the same or substantially similar apparatus and methodology would also be useful in repairing other valves found in the human circulatory systems, particularly other heart valves, such as, for example, venous valves, aortic valves and tricuspid valves, amongst others. OBJECTS OF THE INVENTION [0012] It is an object of the invention to provide a method for the repair of heart valves to increase their efficiency. [0013] It is a further object of the invention to provide for a method for the repair of mitral valves to reduce mitral regurgitation. [0014] It is also an object of the invention to provide for a method for the repair of the mitral valves which eliminates the need for cardiopulmonary bypass surgery. [0015] It is a further object of the invention to provide for an apparatus for percutaneous insertion into the heart to effect the repair of a heart valve. [0016] It is a yet further object of the invention to provide for the repair of a mitral valve by percutaneous insertion of a grasping and fastening device into the heart to repair a mitral valve and reduce or eliminate mitral regurgitation. [0017] These and other objects of the invention will become apparent to one skilled in the art from the more detailed description given below. BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIGS. 1 to 4 are each a schematic representation of a portion of the human heart showing the mitral valve, the left ventricle and an apparatus of the invention in operation; [0019] [0019]FIG. 5 is a schematic representation of an embodiment of the distal portion of an apparatus of the invention useful for grasping a mitral valve; [0020] [0020]FIG. 6 is a schematic representation of an embodiment of a distal portion of an apparatus of the invention showing a configuration of a fastener holder and a fastener clip in the open position; [0021] [0021]FIG. 7 is a schematic representation of an embodiment of FIG. 6 showing the release and closure of the fastener clip; [0022] [0022]FIG. 8 is a detailed, partly cross-sectional schematic representation of the distal end of a preferred embodiment of a grasper device according to the invention in the open position; [0023] [0023]FIG. 9 is a detailed, partly cross-sectional schematic representation of the preferred embodiment of a grasper device according to the invention shown in FIG. 8 in a closed position depicting the translocated adjustable grasper and fastener anvil within the jaws; [0024] [0024]FIG. 10 is a cross-sectional representation across line 10 - 10 of the adjustable grasper shown in FIG. 9; [0025] [0025]FIG. 11 is a detailed schematic representation of a preferred embodiment of the grasper device of the apparatus of the invention in the closed position with the integral closure means shown; [0026] [0026]FIG. 12 is a detailed schematic representation of the preferred embodiment depicted in FIG. 9 showing the closure means piercing the leaflets of the valve; [0027] [0027]FIG. 13 is a detailed, partly cross-sectional schematic representation of yet another preferred embodiment of the distal end of a grasper device according to the invention showing the use of a coil closure means; [0028] [0028]FIGS. 14, 15, and 16 are partly cross-sectional schematic representations of another embodiment of the invention, wherein a self-closing closure is used; [0029] [0029]FIG. 17 is a schematic representation of the self-sealing closure; [0030] [0030]FIGS. 18 and 19 are schematic representations of an embodiment of the invention with a three-piece closure; [0031] [0031]FIG. 20 is a schematic representation of an embodiment of the invention with a three-piece closure; [0032] [0032]FIGS. 21 and 22 are oblique, schematic representations of a valve leaflet closure useful according to the invention; [0033] [0033]FIG. 23 is a partial cross-sectional view of the closure shown in FIGS. 21 and 22; [0034] [0034]FIG. 24 is an oblique, schematic representation of another valve leaflet closure useful according to the invention; [0035] [0035]FIG. 25 is a partial cross-sectional view of the closure in FIG. 24 in position; [0036] FIGS. 26 to 28 are each an oblique, schematic representation of a spiral coil valve leaflet closure useful according to the invention; [0037] [0037]FIG. 29 is an oblique schematic representation of a U-shaped valve leaflet closure useful according to the invention; and [0038] [0038]FIG. 30 is a partly cross-sectional view of the closure shown in FIG. 29. DETAILED DESCRIPTION OF THE INVENTION [0039] The invention can perhaps be better appreciated by making reference to the drawings. In FIG. 1 a portion of the human heart is depicted showing a mitral valve 10 , a left ventricle 12 and the distal end 14 of a grasper apparatus of 20 the invention 16 , which has been inserted through an incision 18 in left ventricle 12 . Incision 18 is loosely sutured with sutures 20 to loosely hold distal end 18 and to prevent bleeding. [0040] Mitral valve 10 comprises anterior leaflet or cusp 22 and posterior leaflet or cusp 24 , as well as two commissural cusps (not shown). The primary intent of the invention herein is to secure the distal sections 26 and 28 of cusps 22 and 24 , respectively, together or substantially adjacent. [0041] As can be seen in FIG. 2, the jaws 30 of distal end 14 are separated and positioned exterior to cusps 22 and 24 . Then, as shown in FIG. 3, jaws 30 are clamped together to cause cusp distal sections 26 and 28 to come together. Once a closure is embedded, such as the loop closure 32 in FIG. 4, jaws 30 are opened slightly so that distal section 14 can be withdrawn. [0042] The distal ends of the grasper means can vary greatly. It is contemplated that a variety of grasper means may be employed having differing grasper configurations and elements. For example, it is contemplated that the grasper means could be of the type wherein one side of the grasper is stationary and the other side movable. Alternatively, the grasper means might be of the type wherein both sides are movable in concert. Another alternative arrangement comprises a grasper means having multiple grasper elements to enable one to grasp and hold the leaflets of the valve in multiple locations. It is also contemplated that the grasper elements themselves might comprise one or more suction elements to secure and hold the valve leaflets in place. Preferably the grasper will have the capacity to adjust the leaflets of, for example, a mitral valve to obtain optimal coaptation. [0043] In addition it is contemplated that the grasper may comprise additional technology to facilitate the operation of the grasper. For example, the grasper may have echo doppler probe or a similar visualization technology that would allow even better localization of the leaflets and confirmation of ideal coaptation. [0044] [0044]FIG. 5 depicts the grasper end 36 of a percutaneous apparatus 38 with jaws 40 in the open position. Jaws 40 of grasper end 36 are movably engaged about joint 42 such that the jaws may be easily and freely opened or closed by the operator of the percutaneous apparatus. [0045] Depicted in FIG. 6 is an embodiment of the invention showing one possible configuration of a fastener holder 44 with a fastener clip 46 in place held in the open position for placement over the grasped leaflets of a mitral valve. The fastener holder 44 and fastener clip 46 may be integral with a grasper end as shown in FIG. 5 or separate from it, in which case it will be necessary to also provide a secondary percutaneous means for use in delivering and manipulating the fastener holder 44 and releasing and fixing the fastener clip 46 in the proper position about the leaves of a mitral valve, once they have been properly grasped by jaws 40 of grasper end 36 . [0046] [0046]FIG. 7 is a more detailed schematic representation of the fastener holder 44 with its jaws 48 in their open position and fastener clip 46 in place in the open position (dotted line). Also shown is fastener clip 46 in its released, closed position. Fastener clip 46 , which may have a closed diameter of from about 3 to 7 mm, preferably about 5 mm, will be comprised of a suitable material such as stainless steel, nitinol, or titanium. [0047] [0047]FIG. 8 depicts a detailed, partly cross-sectional schematic representation of a preferred embodiment of the grasper device of the present invention, comprising grasper end 50 , movable jaws 52 which are movably engaged about joint 54 , in the open position, in proximity to valve leaflets 56 . Each jaw 52 has a protruding grasping surface 58 . However, the grasping surface 58 of one jaw 52 is operatively and slidably connected to a control member 60 to enable one to properly align valve leaflets 56 , prior to fastening. [0048] In FIG. 9 the grasper device of the apparatus of the invention shown in FIG. 8 is in a closed position. Moveable jaws 52 have protruding grasper surfaces 58 , which engage valve leaflets 56 . Leaflets 56 are translocated to a more optimum position for fastening by the action of control member 60 on one of protruding grasping surfaces 58 , as shown in FIG. 11. Also, stapler action rod 68 is now operatively connected to stapler control member 70 . [0049] [0049]FIG. 10 is a schematic representation of a cross section of the adjustable grasper depicted in FIG. 9. The jaws comprise grasper surfaces 58 , an upper anvil 62 with recess 71 , and a lower anvil 64 within which is located a staple type fastener 66 to effect the fastening of valve leaflets. [0050] As shown in FIGS. 9, 11, and 12 , lower anvil 64 has at least one slanted surface member 72 . When stapler action rod 68 is forced distally against slanted surface member 72 , stapler fastener 66 is forced through leaflets 56 into upper anvil 62 to close stapler fastener 66 . [0051] In another embodiment of the invention shown in FIG. 13, a grasper 80 comprises jaws 82 , 84 . Jaw 82 is movably connected to rod 86 at pivot point 87 , and jaw 84 is movably connected at pivot point 88 to rod 90 . Rod 92 is movably connected to jaw 84 at pivot 94 . Operation of rods 90 and 92 causes jaws 82 and 84 to open and close on valve leaflets 96 . Axial to grasper 80 is a sheath 98 containing a drive mechanism 100 for rotating coil fastener 102 . Coil fastener 102 advances in a spiral mode piercing leaflets 96 in multiple locations as coil 102 is advanced into its final position. [0052] Rods 86 , 90 , and 92 are each operatively connected to one or more control mechanisms (not shown). Also, distal section jaws 82 , 84 may be slidable within grasper sheath 81 . [0053] Another device 110 of the invention is shown in FIGS. 14 to 16 , where jaws 112 are operatively connected to a handle mechanism (not shown). Device 110 comprises a movable sheath 114 that contains a straightened closure fastener 116 that is capable of resuming or forming a circular shape to coapt valve leaflets (not shown). Device 110 has a slidably extruding grasping surface 118 that is operatively connected to the handle mechanism. [0054] Once jaws 112 are closed, the distal tip of sheath 114 is advanced distally to be adjacent grasping surface 118 and its cooperating grasping surface 122 . A pusher 124 coerces fastener 116 to advance out of the distal end 126 of sheath 114 to form a circular shape. Fastener 116 in this shape will coapt valve leaflets 120 , as can be seen in FIG. 17. [0055] The device 130 of the invention shown in FIGS. 18 and 19 is intended to form a three-piece closure device. Jaws 132 each removably hold a closure member 134 having a grasping surface 136 . Located axially with device 130 is a closure crimper 138 that is removably fastened at the distal end 140 of a device rod 142 . When jaws 132 grasp valve leaflets 144 , closure crimper 138 is advanced distally by device rod 142 to fit over the proximal ends of closure members 134 . The closure formed is shown in FIG. 20. [0056] While a typical grasper means configuration would normally require the use of at least one control wire to actuate the grasper element(s), it is contemplated that multiple separate control wires could also be effectively employed and manipulated from the proximal end of the system to allow for the precise control of the individual grasper elements. [0057] With regard to the fastening means employed, as noted above it is contemplated that the fastening means may be constituted as a single apparatus operating in concert with the grasper means. Alternatively, the fastening means may be constituted as an entirely separate device which is totally independent of the grasper means. More preferably the fastening means will be a separate device which will function using a monorail type system, wherein the fastening means will operate independently of the grasper means, but will ride via a loop over the same guidewire/catheter which houses and guides the grasper means. [0058] While the preferred fastener depicted is in the form of a clip or staple, it is also contemplated that the fasteners employed to secure the leaflets of the valve may be of a variety of different configurations, each of which would function with greater or lesser effectiveness depending upon the operative conditions which prevail. In addition to clips or staples it is also contemplated that the following types of fasteners may also be effectively employed: coils, sutures, dual button fasteners, cufflink-like fasteners, and the like. [0059] Suitable suture fasteners would include those which might require an appropriate mechanism to automatically suture tissue. Coil fasteners would generally be provided with sharpened ends to allow one to screw these fasteners into place by threading the sharpened end through the tissue of the valve leaflet. [0060] With reference to FIGS. 21 to 23 which depict a sequential representation of the closure of valve leaflets using one preferred closure means, shown in FIG. 22 is a clip type closure 150 being inserted through valve leaflets 152 . FIG. 22 shows the clip type closure 150 in the fastened position. FIG. 23 is a cross-sectional view of the clip type closure 150 depicted in FIG. 23. Each closure 150 as shown in FIG. 21 would have a thickness of from about 0.5 to 1.8 mm, preferably about 1 mm, a width of from about 0.3 to 0.7 cm, preferably about 0.5 cm, and a length of from about 0.6 to 1.4 cm, preferably about 1 cm. [0061] [0061]FIGS. 24 and 25 are each a schematic representation of the insertion of another preferred closure means of the invention. A staple-type closure 156 is inserted through valve leaflets 158 , and then closed, as shown in FIG. 26. Closure 156 would preferably have an overall length (including sides) of from about 1 to 4 cm, preferably about 3 cm, an effective diameter of from about 0.1 to 0.5 mm, preferably about 0.3 mm, and an opening of from about 0.5 to 1.3 cm, preferably about 1 cm. [0062] FIGS. 26 to 28 are each a schematic representation of the insertion of yet another preferred closure. A spiral coil closure 160 can be inserted across valve leaflets 162 in longitudinal, latitudinal, or transverse fashion, by use of, for example, the device shown in FIG. 13. Coils 160 will preferably have pointed ends and will have external dimensions comprising a length of from about 3 to 7 cm, preferably about 5 cm, and a diameter of from about 1 to 3 mm, preferably about 2 mm. [0063] The overall diameter and/or the differential turns of coil 160 may be uniform or they may vary. For example, the diameter at each end of coil 160 could be the same as, greater than, or less than the diameter of the middle portion of the coil. Similarly, the ratio of the turns of the coil to the length, i.e., the pitch, could be consistent or the pitch could be greater or less at each end of the coil. The diameter of the coil wire will preferably be consistent. [0064] Each coil 160 would have a length of from about 3 to 7 cm, preferably about 5 cm, with a diameter of from about 1 to 3 mm, preferably about 2 mm, and a coil wire diameter of from about 0.2 to 0.4 mm. The winding of coil 160 should be from about 5 to 10 turns/cm in an unstressed condition. [0065] In FIGS. 29 and 30 a U-shaped barbed clip-type closure 164 is applied to leaflet 166 . [0066] The device and fasteners used according to the invention must be comprised of biocompatible, nonimmunogenic materials. The grasper is preferably comprised of rigid materials such as titanium, nitinol, stainless steel, or rigid polymeric material such as polyethylene or polyurethane. The clips, staples, coils, etc., are preferably comprised of titanium, nitinol, or stainless steel. In some instances fasteners comprised of molded polymeric material may also be useful. [0067] There are four different approaches which one might take to effect a repair of the mitral heart valve according to the invention: [0068] Such a procedure might be undertaken while the patient is on by-pass with an open-chest, either transapically or transatrially. A median sternotomy is performed and the patient is placed on cardiopulmonary bypass by cannulating the ascending aorta and the right atrium. A purse-string suture is then placed on the apex of the left ventricle and a stab incision performed to insert the instrument which will grasp and attach the mitral valve leaflets. Once adequate repair of the valve is attained, the instrument is removed and the air evacuated from the left ventricle through the apical incision. The ventricle is then repaired using conventional wound closure techniques. [0069] Alternatively, the grasper can be introduced through a similar stab incision performed over the roof of the left atrium. The grasper will cross the valve and then be manipulated to revert to grasp the leaflets from the atrial side and place the suturing device, just as postulated from the transventricular approach. Once adequacy of repair is confirmed, the device is extracted and the atriotomy closed using conventional wound closure techniques. [0070] This procedure can alternatively be performed with the patient off bypass, through either a left or right thoracotomy or a sternotomy incision. The technique would be similar to that outlined for repair of mitral regurgitation on cardiopulmonary bypass. After opening the chest, the patient is placed on medication (beta-blocker) to slow the heart rate to approximately 40 beats per minute. This allows adequate echocardiographic visualization of the leaflets in order to grasp and attach them. [0071] Third, such a procedure can be undertaken thorascopically. The patient is intubated selectively in order to collapse the left lung, and percutaneous ports are inserted in to the left chest allowing visualization of the apex of the heart or left atrium. Through a separate port, the device is introduced into the thoracic cavity and subsequently into the left ventricle through the apex. Previously, a purse-string or triangular suture had been placed around the tip of the ventricle to control bleeding around the ventricular entry site. Subsequent steps of the repair are identical to those described for patients with an open chest, off bypass. [0072] Should the operation require the patient to be placed on bypass, this can be attained percutaneously from the groin by cannulating the femoral artery and vein. This technique could prove particularly useful in the early stages of development of the technique, since the surgeon would be able to operate on a decompressed heart and slow or cease the heart rate as needed, without hemodynamic compromise. [0073] Lastly, a percutaneous approach to repair of the mitral valve would be possible with this invention by inserting the device either through the femoral artery or jugular vein. When using the former, the left ventricle is reached by placing the device across the aortic valve. The leaflets will be grasped by turning the tip of the instrument approximately 160° from the entry angle. As previously stated, the grasper's tips are adjusted to obtain optimal apposition and the suturing device delivered. If a transvenous approach is employed, the left atrium is entered through the interatrial septum and the leaflets are handled as described for the transatrial technique. [0074] To determine the relative efficacy of the method of the invention in effecting the repair of heart valves such as mitral valves a number of procedures were performed on both animal and human test subjects as follows: [0075] Animal Testing [0076] Six adult sheep underwent ligation of OM2 and OM3 through a left thoracotomy to induce chronic ischemic MR. After 8 weeks, animals were placed on cardiopulmonary bypass. Using a posterior approach to the left atrium, a bow-tie repair was performed. A posterior suture annuloplasty (DeVega) served as control. Snares were placed on both repairs to allow alternate tightening during measurements. Ten 2-mm piezo-electric crystals were sutured around the MV annulus and at the bases and tips of the papillary muscles. Six crystals were secured to the apex ( 1 ), septum ( 1 ), and epicardial short axis of the left ventricle ( 4 ) for 3-dimensional sonomicrometry array localization (3D-SAL) imaging. 3D-SAL measurements were performed after weaning from cardiopulmonary bypass at baseline and with each type of repair. Echocardiography was used to measure MR, MV area, and fractional shortening. TABLE 1 MR, mitral valve area, and fractional shortening MR FS MVA (cm 2 ) Baseline 3.3 0.46 5.4 DeVega 1.4 0.53 31.9 Bow-tie 1.2 0.57 3.3 [0077] As shown from the results presented in Table 1, MR decreased significantly with both repairs compared with baseline. Post-operative improvements in fractional shortening was greater in the bow-tie group but did not reach statistical significance. MVA, measured by planimetry, decreased more with the bow-tie repair; nevertheless, the resultant areas were still substantial without evidence of a transvalvular gradient. Mitral valve annular contractility (% area change=(maximum area−minimum area)/maximum area) by 3D-SAL increased from 19.7%±4.0% at baseline to 21.5%±3.2% after bow-tie repair (P=0.026). Suture annuloplasty decreased annular contractility to 15.7%±3.6% (P=0.0011 vs. baseline, and P=0.0001 vs. bow-tie). [0078] The results obtained suggest that current techniques of mitral valve repair in ischemic MR may further impair left ventricular performance by limiting systolic function of the annulus and base of the heart. The bow-tie repair technique which is the subject of the present invention controls MR and directly addresses subvalvular dysfunction resulting in improved annular and left ventricular function. [0079] Human Testing [0080] The charts of eleven patients (five males and six females) undergoing mitral valve repair in conjunction with a central leaflet suture (“bow-tie” repair) were reviewed. Patients were operated on between August1996 and April 1997. Mean age was 68 years (range, 44 to 78). Etiology of mitral regurgitation (MR) was ischemic in nine patients and degenerative in two. Mitral regurgitation was attributed to ischemia if any of the following criteria proposed by Radford et al. was met: (1) rupture of a papillary muscle chord or head (n=3); (2) infarction of the papillary muscle in the absence of leaflet pathology (n=3); (3) clear history of new onset or worsening of mitral regurgitation after documented myocardial infarction (n=3). [0081] The diagnosis of MR was established by echocardiography in 10/10 patients, and semiquantitatively graded as severe (4+), moderate/severe (3+), mild/moderate (2+), mild (1+), and trace. Left sided cardiac catheterization confirmed the presence of MR in nine patients and the presence of critical coronary artery disease (CAD) invariably involving the circumflex and posterior descending artery territories in all patients with ischemic MR. Preoperative diagnoses and hemodynamics obtained during catheterization are shown in Table 2. All patients were in NYHA class III or IV at the time of surgery. TABLE 2 Preoperative diagnosis and hemodynamics. Patient Diagnosis Age CO PCWP v-wave 1 Unstable angina 59 4.2 30 80 2 CAD/torn post. chord 78 2.4 6 10 3 CAD 74 n/a 14 15 4 CAD/MIx3 64 n/a n/a n/a 5 Unstable angina/MIx2 44 4.0 26 41 6 Ischemic VSD 77 4.0 28 21 7 AI/MR 77 4.5 29 39 8 CAD/APM rupture 67 4.3 27 65 9 CAD/V-tach arrest 71 4.1 20 28 10 Degenerative MR 70 3.5 20 21 11 AMI/PPM rupture 67 4.1 33 60 [0082] AI-aortic insufficiency; AMI-acute myocardial infarction; APM-anterior papillary muscle; CAD-coronary artery disease; post-posterior; PPM-posterior papillary muscle; VSD-ventricular septal defect; v-tach-ventricular tachycardia [0083] With the patient under anesthesia, the valve is visualized on transesophageal echocardiogram (TEE) and the likely mode of failure determined, with special emphasis on the presence of leaflet prolapse and site and direction of the regurgitant jet. After the heart was stopped, a bulb syringe with cold saline is used to distend the left ventricle and confirm the mode of valve failure. A conventional repair using an annuloplasty right is generally performed and the valve is reinspected with saline injection. If the leaflet edges do not oppose each other in a concentric circle parallel to the annuloplasty ring, and continued regurgitation is observed, then a “bow-tie ” repair is iniatiated. If the repair is performed from the tranventricular or transaortic exposure, a single figure of eight 4-0 prolene suture is placed without screening leaflet eight 4-0 prolene suture is placed without screening leaflet coaptation. Using a 4-0 prolene suture, the anterior leaflet is attached to the corresponding posterior leaflet at the site of malapposition. The figure of 8 suture is placed through each leaflet just as the edge turns down to attach to the primary chordae. This is usually the most cephalad site where the 2 leaflets would touch during systole and creates the largest area of coaptation possible. [0084] At time the suture is very close to a commissure and the result is a narrowing of single valve orifice. More commonly, the suture is closer to the center of the valve and a double orifice valve is created which resembles a “bow-tie”. After visually confirming that the repair is satisfactory with cold saline injection, the atrium is closed, the patient weaned from CPB, and an intraoperative TEE used to confirm the adequacy of the repair. Standard as well as exercise transthoracic echocardiograms were performed prior to discharge to establish the competency of the “bow-tie” repair as well as the absence of a significant gradient across the valve. [0085] Six patients were operated on electively for worsening MR leading to intractable congestive heart failure or unstable angina. Four patients underwent emergent operation due to acute worsening of MR secondary to ischemic anterior papillary muscle rupture (n=2), acute MI with cardiogenic shock requiring intraaortic counterpulsation balloon, severe MR and malignant arrhythmias (N=1 ), and acute worsening of chronic degenerative MR (n=1 ). One patient had moderate (3+0) MR in association with critical aortic insufficiency. Mean degree of preoperative MR by echo was 3.5±0.7, with mean ejection fraction (EF) of 42%±17%. Nine patients underwent preoperative cardiac catheterization. Mean pulmonary capillary wedge pressure was 23 mmHg±8 mmHg, with mean atrial v-wave of 39 mmHg±25 mmHg; mean CO as measured by thermodilution technique was 3.9 1/min (range 2.4 to 4.5 1/min) (Table 2). Concomitant procedures performed at the time of MR included coronary artery bypass grafting (CABG) in eight patients. Of the two patients with a degenerative etiology of valvular disease, one required aortic valve replacement, whereas the second underwent posterior leaflet quadrangular resection and annuloplasty. Two patients, not included in this series, with end-stage congestive heart failure (CHF) secondary to ventricular dilation had “bow-tie” repairs during partial left ventriculectomy. Nine patients had a posterior ring annuloplasty as primary procedure for treatment of MR (Table 3). One patient required repair of ischemic ventricular septal defect (VSD) through a ventriculotomy, which made insertion of an annuloplasty ring impractical. This patient's mitral valve was successfully repaired with a “bow-tie” alone. A second patient presented with acute MR secondary to rupture of the anterior head of the ppm. Repair of the papillary muscle was performed using pericardial pledgets. Due to the lack of annular dilatation and persistence of MR a “bow-tie” suture was placed without an annuloplasty ring. Control of MR assessed intraoperatively by direct cold saline injection and TEE was satisfactory in all patients. TABLE 3 Operative indications and concomitant procedures Patient Operative indication Other procedures 1 MR. unstable angina CABG, C-E#28 2 Torn post chord, MR Post quad resection, C-E #32 3 CAD, MR CABG, C-E#32 4 CAD, MR CABG, C-E#30 5 Unstable angina, MR CABG, C-E#28 6 Ischemic VSD, MR CABG 7 Critical AI, MR AVR, C-E#30 8 CAD, ALM rupture, MR CABG, C-E#26 9 CAD, MR CABG, C-E#28 10 MR, CHF C-E#30 11 PPM rupture, MR CABG, primary PPM repair [0086] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. [0087] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. DRAWING COMPONENTS No. Component 10 mitral valve 12 left ventricle 14 distal end of grasper 16 grasper 18 incision 20 suture 22 anterior leaflet or cusp 24 posterior leaflet or cusp 26 anterior cusp distal section 28 posterior cusp distal section 30 jaw 32 closure loop 36 grasper end 38 percutaneous apparatus 40 jaw 42 joint 44 fastener holder 46 fastener clip 48 jaw 50 grasper end 52 jaw 54 joint 56 valve leaflet 58 protruding grasping surface 60 control number 62 upper anvil 64 lower anvil 66 staple type fastener 68 staple action rod 71 recess 72 anvil slanted surface 80 grasper 81 grasper sheath 82 jaw 84 jaw 86 rod 87 pivot point 88 pivot point 90 rod 92 rod 94 pivot 96 valve leaflet 98 sheath 100 drive mechanism 102 coil fastener 110 grasper device 112 jaw 114 sheath 116 fastener 118 grasping surface 120 leaflet 122 cooperating grasping surface 124 pusher 130 grasper device 132 jaw 134 closure member 136 grasping surface 138 closure crimper 140 rod distal end 142 device rod 144 valve leaflet 150 clip-type closure 152 valve leaflet 156 staple-type closure 158 valve leaflet 160 spiral closure 162 valve leaflet 164 barbed-clip closure 166 valve leaflet	An apparatus for the repair of a cardiovascular valve has leaflets comprising a grasper capable of grabbing and co-apting the leaflets of the valve. In a preferred embodiment the grasper has jaws that grasp and immobilize the leaflets, and then a fastener is inserted to co-apt the leaflets. The apparatus is particularly useful for repairing mitral valves to cure mitral regurgitation.	0
[0001] This application claims priority from provisional application Ser. No. 60/738,093, filed on Nov. 18, 2005, which is incorporated herein in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to compositions of plastics and additive packages that have high fire resistance characteristics. In particular, the invention relates to compositions of plastics and additive packages that contain nanoclays, which substantially maintain the processing characteristics of plastics and are highly flame retardant. BACKGROUND OF INVENTION [0003] Most plastic materials are highly flammable and this limits their use in many products, especially building materials. Federal, state and municipal fire codes require building materials to pass different tests before they can be used for construction new buildings or the renovation of existing structures. This has significantly reduced the use of plastic products in the construction industry. Numerous attempts have been made to reduce the flammability of plastic products by adding different additives that have fire retardant or fire resistance characteristics. However, none of these attempts has produced a fire resistant plastic composition that can be easily processed and used as a substitute for non-fire resistant plastic formulations. [0004] Flame retardants are materials that inhibit or resist the spread of fire. Brominated flame retardants (BFRs) is the designated name for a group of brominated organic substances that have an inhibitory effect on the ignition of combustible organic materials. BFRs are commonly used in electronic products as a means of reducing the flammability of the product and they are also use in clothes and furniture. The electronics industry accounts for the greatest consumption of BFRs. In computers, BFRs are used in four main applications: in printed circuit boards, in components such as connectors, in plastic covers, and in cables. BFRs are also used in a multitude of products, including plastic covers of television sets, carpets, paints, upholstery, and domestic appliances. BFRs have such a widespread number of applications because they are incredibly effective at fire prevention. In addition to reducing the likelihood that an article will ignite, brominated flame retardants hinder the spread of the fire. [0005] Polybrominated diphenyl ether (PBDE) is a flame-retardant sub-family of the brominated flame-retardant group. Among the group of polybrominated diphenyl ethers used as flame-retardants, the fully brominated diphenyl ether, decabromodiphenyl ether (decaBDE), is the most commonly used. PBDEs have been used in a wide array of household products, including fabrics, furniture, and electronics. There are three main types, referred to as penta, octa and deca for the number of bromine atoms in the molecule. However, PBDEs, like other BFR's, are not aways completely compatible with plastic materials, such as polyolefins, and this has limited their use. Accordingly, ther is a need for a composition that includes PBDEs and different polyolefins, particularly, polypropylene. [0006] Like most other plastic materials polypropylene and materials formed from polypropylene are flammable. Most materials containing polypropylene will also degrade over time when exposed to ultra violet (UV) light. Therefore, there is a need for polypropylene compositions that can be used to form materials which have a high flame retardance or fire resistance and are not subject to degradation when exposed to UV light. The present invention addresses both of these problems by forming compositions containing fire retardant PBDEs that are compatible with polyolefins. SUMMARY OF THE INVENTION [0007] The present invention is a flame retardant composition that includes: a polyolefin; a brominated polystyrene or decabromodiphenyl ether; a nanoclay; and carbon nanotubules in the nanometer particle range. The nanoclay is preferably a quantenary amine treated nanoclay, wherein the quantenary amine causes exfoliation of the nanoclay. The most preferred nanoclays are smectite, bentonite, hectorite, beidellite, stevensite and saponite. [0008] The polyolefin is preferably a polyethylene or a polypropylene, more preferably high density polypropylene, high density polyethylene, low density polyethylene, a polyethylene-polypropylene copolymer, a cured polybutadiene liquid, medium density polyethylene, linear low density polyethylene, ethylene propylene elastomer, medium density polypropylene, or low density polypropylene. The preferred metal oxide is antimony oxide. [0009] In preferred embodiments, the flame retardant composition includes from about 30% to about 50% by weight polyolefin; from about 30% to about 40% by weight decabromodiphenyl ether; from about 10% to about 30% by weight exfoliated clay; and from about 5% to about 15% by weight carbon nanotubules or metal oxide fillers. In another embodiment flame retardant composition includes from about 30% to about 60% by weight polyolefin; from about 10% to about 25% by weight brominated polystyrene; from about 10% to about 30% by weight exfoliated clay; and from about 5% to about 15% by weight carbon nanotubules or metal oxide fillers. These flame retardant compositions comply with the requirements of ASTME-84 for flame retardance. [0010] The present invention is also a method for producing a flame retardant material. The method includes: heating a polyolefin resin to a first temperature, wherein the polyolefin melts; mixing a quantenary amine treated nanoclay with the melted polyolefin resin to form a first molten mixture; mixing an antimony oxide and a decabromodiphenyl ether or a brominated polystyrene with the first molten mixture to form a second molten mixture; and heating the second molten mixture to a second temperature to form a fire resistant material. In a preferred method, the fire resistant material is formed into an article by one of the well know methods for forming plastic articles, such as extruding or molding. [0011] The first temperature is greater than or equal to the melting temperature of the polyolefin to ensure that the polyolefin is melted before it is mixed with the nanoclay. This allows the nanoclay to be evenly distributed in the polyolefin. The second temperature is greater than or equal to the melting temperature of the decabromodiphenyl ether or a brominated polystyrene. The second temperature is typically greater than the first temperature since decabromodiphenyl ether or a brominated polystyrene have higher melting temperatures than most polyolefins. [0012] The present invention is also a method for producing a flame retardant material which includes combining brominated polystyrene, polypropylene, a compatibilizer and an exfoliated clay, carbon nanotubules, or metal oxide fillers in the nanometer particle range. DETAILED DESCRIPTION OF THE INVENTION [0013] The present invention is directed to additive packages which are added to plastics to form compositions that meet UV and flame retardant (FR) standards. These additive packages can be used with a variety of different plastic resins to render the compositions substantially inflammable. At high loading levels (i.e., compositions that contain up to 70% by weight of the additive packages), the material is still easily processed using standard plastic processing equipment. When formed into sheets or articles, the compositions do not drip during flame testing and are substantially UV inert. The plastic resins also maintain good mechanical properties after loading with high weight percentages of the additive package. The polyolefin/additive package compositions of the present invention are inflammable and have many uses in architectural and consumer related materials. [0014] This invention is for additive packages which are added to plastic resins to provide protection against UV exposure and to improve fire retardant characteristics. When the additive packages are added to plastics resins, the plastic composition formed becomes substantially unflammable and does not break down when exposed to UV light. Materials formed from these compositions easily pass one of the most stringent flame tests for architectural materials, ASTM E-84 or the Steiner Tunnel Test, which typically is not used to test plastic materials. In addition, the fire retardant compositions of the present invention comply with fire codes for non-plastic materials and are not degraded by exposure to UV light like most plastic materials. [0015] The ASTM E-84 tunnel test is designed to test the flame spread characteristics and smoke generation of flat surface building materials used for exposed surfaces, such as ceilings and walls, in a controlled burn chamber. The ASTM E-84 tunnel test compares surface burning characteristics of tested materials to those of asbestos cement board and untreated red oak lumber. A rating of 0 is assigned to asbestos cement board and a rating of 100 is assigned to untreated red oak flooring. Flame spread ratings of various species of untreated lumber range from 60 to 230. During this test, smoke emissions are also measured and ratings are assigned on the same scale. When tested, the compositions of the present invention had very low flammability ratings, almost as low as asbestos cement board. [0016] The materials made from the composites of the invention do not readily degrade and any chemicals in the composites that could possibly be toxic are kept in a safe, inert form (i.e., encapsulated). The flame retardants used are commercial flame retardants (metal salts or halogenated compounds), which are readily available. Moreover, the flame retardants used are non-leachable and thus, environmentally friendly. The materials made from the compositions of the present invention are especially useful for construction and provide an inexpensive and safe replacement for lumber that is now used in homes and commercial buildings. [0017] The present invention is distinguished from the prior art by the high percentages of additive package in the plastic compositions. The amount of additive package in the prior art was limited by the compatibility of the plastic resins with the additive package. The present invention uses a nanoclay to compatibilize the additive package and the plastic resins. This allows the compositions to contain higher amounts of additive package and provide correspondingly higher flame retardance to the compositions that are formed. Moreover, these compositions with high additive package loading rates also have unexpectedly good processability. The exfoliated clay, carbon nanotubules, or metal oxide fillers in the nanometer particle range make the compositions easier to process and reduce the process temperature requirements by 10-20% for ASTM E-84 flame retardant applications. This allows the compositions to be processed using conventional extrusion and molding methods into a wide variety of different articles and products. In the prior art, compositions with high additive package loading rates could not be processed and were, therefore, all but unusable. [0018] The present invention includes the use of a nanoclay in compositions that include polyolefins, such as polypropylene, and additive packages to increase the fire retardant properties of materials made from the compositions. These maintain many of the properties and processing characteristics of the polyolefins and can be used to replace aluminum and steel in many applications which require UV inhibiting and/or flame retardant materials. Even though the fire retardant compositions lack the flexibility of the unfilled pololefins, compositions formed using lower molecular weight polyolefins have been found to be well adapted for uses as compounding agents and as primary raw materials. Without the nanoclay compatibilizer, these compositions with the high percentage of additive package would not retain sufficient polyolefin characteristics to have any significant industrial uses. [0019] The high loading of flame retardant fillers as well as nanoclay to polyolefins is achieved by adding the components of the compositions in a specific sequence. The polyolefin is first heated to a temperature above its melt temperature and mixed with the nanoclay until the nanoclay is evenly distributed in the polyolefin. The fire retardant material, preferably brominated polystyrene or decabromodiphenyl ether, is then mixed into the polyolefin/nanoclay mixture and heated to a temperature above the melt temperatures of the polyolefin and the fire retardant material. The antimony oxide is then added and the composition is thoroughly mixed. Besides acting as a compatibilizer, the nanoclay adds barrier properties to the composition; slowing loss of mass and forming a ceramic composite layer when subjected to char forming conditions, i.e. flame. [0020] In one embodiment, the present invention relates to flame retardant polypropylene compositions. Polypropylene as well as compositions and articles formed from polypropylene are highly flammable. The flame retardant characteristics of the additive package of the present invention are transferable, i.e., when these additive packages are combined with the polypropylene resins, they form compositions that are flame retardant. The polypropylene compositions can be used in a variety of structural, mechanical and load bearing applications, where the polypropylene must have high flame resistance characteristics. Moreover, the polypropylene-containing materials and articles can undergo high UV exposure and not degrade over time in mechanical functionality. [0021] In preferred embodiments, compositions with increased flame retardance properties are formed by combining brominated polystyrene (both high and low molecular weight), polypropylene, a compatibilizer (preferably antimony oxide (Sb 2 O 3 ) and maleic anhydride) and either an exfoliated clay, carbon nanotubules, or metal oxide fillers in the nanometer particle range. The exfoliated clays are described in U.S. Pat. No. 6,339,121 to Rafailovich, et al., which is incorporated herein in its entirety. These compositions can be used to form flame retardant materials which meet the requirements of ASTME-84 for flame retardance. In another embodiment, polybrominated diphenyl oxides can be combined with nylon to form materials that can be used in flame retardant applications where ASTEM E 4 flame retardance is required. [0022] The compositions of the present invention are formed by combining one or more plastic resins and an additive package, preferably using a melt-mixing process. The plastic resins can be any thermoplastic resin, preferably a polyolefin, a polystyrene, a polyamide, a polyvinyl, a polycarbonate or a polysulfone and most preferably polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC or vinyl), polypropylene (PP), polyvinylidene chloride (PVDC, Saran™), ethylene-vinyl alcohol (EVOH) or ethylene-vinyl acetate (EVA). The polyolefin can also include different processing additives and modifiers that would ordinarily be added to a plastic resin, such as colorants and lubricating agents. [0023] The fire retardant material can be a brominated phenyl ether. Brominated phenyl ether are those compounds having at least one bromine atom bonded to the phenyl ether group. Examples include 2,3-dibromopropylpentabromophenyl ether, bis (tribromophenoxy) ethane, pentabromophenylpropyl ether, hexabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether and polydibromophenylene oxide. [0024] The invention is for a filler package added in a specific sequence which allows for very high loading of flame retardant fillers as well as nano-clay. The nanoclay adds barrier properties; slowing loss of mass, while also forming a ceramic composite layer when subjected to char forming conditions; i.e. flame. The flame used for the testing conformed to UL-94 conditions with the exception that the flame exposure time was exceeded. For the experiments, the plastic was continuously left in the flame. After quick char formation the first 1 or two mills (25-50 microns) of the plastic surface was converted into a ceramic composite material which shields the inner core of the plastic composite found under this ceramic char layer. After the thin dark layer, no change in coloration, or bubbles from off-gassing and melting of the polymer were visible. Even though the material lacks the flexibility of the unfilled polymer, the use of lower molecular weight polyolefins both as compounding agents and as primary raw materials. [0025] A substantially inflammable polyolefin composition that includes from about 30 to about 50% by weight, preferably from about 35% to about 45% by weight of a polyolefin and from about 50% to about 70% by weight, preferably from about 55% to about 65% by weight of an additive package. The additive package includes a nanoclay, a polybrominated diphenyl ether and antimony oxide. The flame retardant composition includes from about 20% to about 60% by weight polyolefin, preferably from about 30% to about 50%; from about 20% to about 50% by weight decabromodiphenyl ether, preferably from about 30% to about 40% by weight; from about 5% to about 30% by weight exfoliated clay, preferably from about 10% to about 25% by weight; and from about 5% to about 15% by weight carbon nanotubules or metal oxide fillers, preferably from about 8% to about 12% by weight. In another embodiment flame retardant composition includes from about 30% to about 60% by weight polyolefin, preferably from about 30% to about 60% by weight; from about 10% to about 35% by weight brominated polystyrene, preferably from about 10% to about 25% by weight; from about 5% to about 30% by weight exfoliated clay, preferably from about 10% to about 25% by weight; and from about 5% to about 15% by weight carbon nanotubules or metal oxide fillers, preferably from about 8% to about 12% by weight. The preferred metal oxide filler is antimony oxide in an amount of from about 8 to about 12% by weight, preferably about 10% by weight. [0026] The amount of additives which are combined with the plastic resins to form the compositions of the present invention vary over a wide range depending on the additive used and the resin or resins combined with the additive. For example, in a preferred embodiment, the ranges of additives for polypropylene nanocomposite transferable flame retardant package material containing: up to 50% by weight a total aggregate additive antomony oxide 5-30% by weight maleic anhydride grafted polystyrene 1-20% by weight exfoliated clay, carbon nonotubules, or metal oxide fillers in the nonometer particle size 3-20% by weight. [0031] A preferred embodiment of the present invention is a non flammable polypropylene composition that does not bum under ASTM E-84 tunnel test conditions. Polypropylene is normally flammable. However, the compositions of the present invention which contain polypropylene do not bum and maintain acceptable processability even with high percentages of the additive package. The combination of polypropylene with flame retardants and nanoclays provides compositions that form clay thermo-shields under bum conditions. After being subjected to prolonged bum conditions, the plastic compositions remain substantially intact and unchanged at 1.5-3 mils below the surface without discoloration. [0032] The flame used for the testing was in conformance with UL-94 conditions with the exception that the flame exposure time was exceeded, i.e., for the experiment, the plastic was continuously left in the flame. After quick char formation, the first 1 or two mills (25-50 microns) of the plastic surface was converted into a ceramic composite material which shielded the inner core of the plastic composite under this ceramic char layer. After the thin dark layer, no change in coloration, or bubbles from off-gassing and melting of the polymer were visible. [0033] Thus, while there have been described the preferred embodiments of the present invention, those skilled in the art will realize that other embodiments can be made without departing from the spirit of the invention, and it is intended to include all such further modifications and changes as come within the true scope of the claims set forth herein.	A fire retardant composition that includes: a polyolefin and an additive package that includes a brominated polystyrene or decabromodiphenyl ether; a nanoclay; and metal oxide fillers in the nanometer particle range. The compositions can have high weight percentages of the additive package because of the compatibilizing effect of the nanoclay. The nanoclay is preferably a quantenary amine treated nanoclay, wherein the quantenary amine causes exfoliation of the nanoclay. The polyolefin is a polyethylene or a polypropylene and the preferred metal oxide is antimony oxide.	2
RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application No. 61/846,703, filed on Jul. 16, 2013. [0002] The entire teachings of the above application is incorporated herein by reference. BACKGROUND OF THE INVENTION [0003] First reported in 2005, bio-printers (adapted inkjet printers) were developed to try and meet the challenge of printing 3D organs, but they have had very limited success (3-17). They fabricate structures via a dropwise printing of cells with an extracellular matrix (ECM) material, which serves as the “bio-glue”. The bio-glue gels within minutes, but the cells require tens of hours to attach to the ECM. Recently, bio-printers have become commercially available (EnvisioTec, Organovo, Inc). However, success is limited to simple structures such as a single tube or an array of spheroids (17). The structures survive by passive diffusion and none even begin to approach the complexity, nor cell density of an organ. Bio-printers are also limited by slow throughput inherent in the small size/simplicity of their building materials as well as the vast number of building units that must be deposited. Bio-printers deposit (one at a time) a drop of either a spheroid (˜1,000 cells) or liquid ECM. Our single honeycomb building part has 6×10 6 cells, equivalent to 6, 000 spheroids. Bio-printers are not creating thick structures with sufficient density of cells to require perfusion. They are creating structures of modest thickness, high ECM content and low cell density that do not require perfusion. [0004] Current pick-and-place instruments from the electronics industry are not suitable, nor could they be easily modified since our building must always occur within an aqueous environment of cell culture medium. We also investigated microbiology instruments for picking bacterial colonies and these were deemed not suitable because they locate a colony and punch out a small plug of agarose and dispense this plug (with colony) to a 96 well plate. These instruments (e.g., Hudson Robotics) are designed for very high throughput, do not have the precision we need, would certainly damage our tissues and cannot grip, let alone perfuse a growing organ. Hence, there is no off the shelf pick and place device available which we can modify for our intended research projects. [0005] Therefore, a new device and method are that overcome or minimize the above-referenced problems. SUMMARY OF THE INVENTION [0006] The invention generally is directed to a device and method for assembling aggregations of adherent cells. [0007] In one embodiment, the invention is a device for assembling aggregations of adherent cells that includes an assembly vessel. A gripper is movable within the assembly vessel. The gripper includes a gripper housing defining a gripper chamber and at least two openings, a gripper membrane over one of the openings, a conduit extending from another of the openings of the gripper, and a support at the gripper housing that controls the position of the gripper within the housing. A perfusate source is in fluid communication with the conduit extending from the gripper housing. A build support is fixed within the assembly vessel that includes a build housing defining a build chamber and at least two openings, a support membrane over one of the openings, and a conduit extending from another of the openings of the build support to the perfusate source. [0008] In another embodiment of the invention, a method of assembling aggregations of adherent cells includes the step of securing a first aggregation of cells to a gripping membrane by directing a perfusate through the gripping membrane. The gripping membrane is moved to a build membrane opposing the gripping membrane, and the first aggregation of cells is transferred from the gripping membrane to the build membrane by directing perfusate across the first aggregation of cells in a direction toward the build membrane and then through to build membrane. A second aggregation of cells is secured to the gripping membrane by directing perfusate through the gripping membrane. The gripping membrane is moved to the first aggregation of cells at the build membrane, and the second aggregation of cells is transferred from the gripping membrane to the first aggregation of cells by directing perfusate across the second aggregation of cells and the first aggregation of cells and then through the build membrane, whereby the first and second aggregations of cells are stacked on the build membrane, thereby assembling the aggregation of cells. [0009] The device and method described herein are in the field of tissue engineering, namely the in vitro engineering of thick tissues of high cell density. “Thick tissue,” as that term is defined herein, means tissues that are greater in thickness than 200 microns. [0010] “High cell density,” as that term is defined herein, means at least about 10 8 cells/ml. An example of tissue having “high cell density” is the human liver. The number of cells in the human liver is estimated to be ˜240 billion (Bianconi et al. An Estimation of the Number of Cells in the Human Body. Annals of Human Biology, 40, 463-471, 2013). The volume of the liver, which needs to be estimated for purposes of partial hepatectomy, is ˜2 liters (Heinemann et al., Standard Liver Volume in the Caucasian Population. Liver Transplantation and Surgery 5: 366-368, 1999). Thus, cell density in a real liver is 10 8 cells/ml. [0011] The device of the invention does not rely on bio-inks that might be toxic and need to be washed out of a construct. Also the device of the invention can employ large living parts that have very high cell density. The living parts are formed by cells aggregating with each other (cell-driven self-assembly). [0012] The invention, however, is not limited to thick tissue and high cell density; it can be employed to pick, place and perfuse materials that are not “thick” or of “high cell density.” [0013] It assembles relatively large 3D tissues/organs layer-by-layer using a controllable low level suction head to pick up living microtissue building parts and place them onto other microtissue building parts in precise locations, while maintaining perfusion as these parts fuse and the living structure is built. This is a versatile building platform that can grip multi-cellular building parts of any size, shape and cell type. Large living building parts in the shape of a honeycomb and, when stacked, the aligned lumens of these honeycomb parts will form channels that enable perfusion of the organ under construction. Success at breaking this “sound barrier” and the ability to build organs in vitro has a far-reaching impact in the field of tissue engineering as well as many other areas of research that use animals. Many of these programs have an unmet need to create new more complex 3D in vitro models (test beds) that more accurately mimic the complexity of in vivo. In addition to reducing the use of animals in research, these models are less expensive and more amenable to investigation. The device and method of the invention can be employed to construct complex 3D test beds of tissues of specified shape and size to study these cellular and molecular events; and to understand the transport of drugs and small molecules. [0014] Investigating and modeling the 3D transport of drugs into tissues, the effects of drugs known to inhibit efflux pumps such as Pgp (P-glycoprotein is an efflux drug transporter), that move small molecules and drugs out of cells, quantitative 3D model and algorithm will facilitate discovering new, more effective inhibitors of drug efflux transporters, 2D cell culture does not adequately mimic drug transport in vivo, which is, more often than not, through multiple layers of different cells. The device also constructs complex 3D test beds of different cell types, layering of cells and composite microtissues of different cell types (normal & pathologic) into desired shapes. [0015] The device assembles/engineers large 3D tissues/organs layer-by-layer using a controllable, low-level fluid suction head to pick up living building parts and place them onto other building parts in precise locations while maintaining perfusion as this living structure is built. This is a versatile building platform that can grip multi-cellular building parts (of any size and shape), image the part it has gripped and then precisely place this part onto a stack of living building parts to effect the layer-by-layer engineering of a solid organ. Each living part has carefully designed lumen structures and is composed of tens of millions of cells formed in specific geometries designed to be stacked and used to build a large 3D tissue/organ complete with a branched tubular (vascular) network for perfusion. Each living part can be designed to have lumens of different sizes and when these building parts are stacked, their lumens can align to form a branching tubular network that can be perfused. An example of a suitable prior art building part is a large honeycomb structure ( FIG. 1 ), as described in Tejavibulya, N., et al., Directed Self-Assembly of Large Scaffold-Free Multi-Cellular Honeycomb Structures, Biofabrication 3, 1-9, 2011. The honeycomb-shaped building part can be made by seeding mono-dispersed cells into specially designed non-adhesive agarose micro-molds. Within twenty-four hours, the cells in this scaffold-free environment aggregated and self-assembled a multi-cellular structure in the shape of the honeycomb. The contiguous multi-cellular honeycomb formed around agarose posts which directed the formation of lumens in the honeycomb. This tissue sheet is 2 cm end-to-end in the x, y dimensions and less than 200 μm in the z dimension. Thus, each cell in the honeycomb receives adequate oxygen and nutrients because it is no more than 100 μm away from the top surface, bottom surface or the surface of a nearby lumen. Using CAD and rapid prototyping, micro-molded hydrogels of virtually any size and shape can be designed and these micro-molds direct self-assembly of living cells into the final shape of the building part. This process works for over fifty different cell types including primary human cells from a variety of tissues and organs. And further, these living building parts will readily fuse with one another to form even larger prior art living structures, as described, for example, in Livotti and Morgan Tissue engineering Livotti, C. M., and Morgan, J. R. Self-Assembly and Tissue Fusion of Toroid-Shaped Minimal Building Units. Tissue Eng. 16: 2051-2061, 2010 (PMCID: PMC2949232). [0016] Shown in FIG. 2 , are two prior art toroid-shaped parts of liver cells that have fused within two days published in Livotti and Morgan. Fusion does not occur between building parts made using conventional tissue engineering approaches where cells are seeded onto a scaffold. Because the parts are made entirely of cells with no added scaffold, they fuse with each other via the same cell-to-cell contacts that drove the self-assembly of the original part from millions of individual cells. Thus, we have a process that can potentially make an indefinite number of building parts of any design in two days, and these parts can be fused within four days to form a larger structure. BRIEF DESCRIPTION OF THE DRAWINGS [0017] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. [0018] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention. [0019] FIG. 1 is a photograph of one embodiment of a prior art aggregation of cells configured as a honeycomb, and suitable as a viable building unit by the device and method of the invention. The honeycomb included about 6×10 6 cells formed in a micro-mold and stained for viability after 24 hrs. Viable cells are green. Dead cells are red. Shown is the merged red and green fluorescent stitched image. Bar 1800 μm. (1). [0020] FIG. 2 are photographs of Toroids (about 20,000 cells each) suitable for use in the present invention and undergoing fusion in all dimensions. Two prior art self-assembled toroids placed adjacent on flat nonadhesive agarose fused in the x-y (horizontal) plane. Images at days 0, 2, 4 ( FIGS. 2A-2C ). Bars 200 μm. [0021] FIG. 3 is a schematic representation of one embodiment of a device of the invention, wherein an aggregation of cells is supported by a staging support. [0022] FIG. 4 is the embodiment of the device of FIG. 3 , wherein a gripper of the invention has been lowered to the aggregation of cells supported by the staging support. [0023] FIG. 5 is the embodiment of the device of FIG. 4 , wherein the gripper has been raised from the staging support while gripping the agglomeration of cells. [0024] FIG. 6 is the embodiment of the device of FIG. 5 , wherein the gripper has been rotated about a vertical axis to thereby bring the aggregation of cells into proximity of a build support of the invention. [0025] FIG. 7 is the embodiment of the devices of FIG. 6 , wherein the gripper has been brought into essentially vertical alignment with the build support by movement of the assembly vessel in a horizontal (x,y) plane. [0026] FIG. 8 is the embodiment of the device of FIG. 7 , wherein the gripper has been lowered to the build support to thereby place the aggregation of cells on the build membrane. [0027] FIG. 9 is the embodiment of the device of FIG. 8 , wherein the gripper has been raised after release of the aggregation of cells on the build support membrane. [0028] FIG. 10 is the embodiment of the device of FIG. 9 , wherein the vessel has been moved in a horizontal plane to prepare the gripper for rotation about the vertical axis prior to gripping a second agglomeration of cells. [0029] FIG. 11 is the embodiment of the device of FIG. 10 , wherein the gripper has been rotated about the vertical axis to thereby align the gripper with the staging support for gripping the second agglomeration of cells. [0030] FIG. 12 is the embodiment of the device of FIG. 11 , wherein a second agglomeration of cells has been placed on the staging support. [0031] FIG. 13 is the embodiment of the device of FIG. 12 , wherein the gripper has been lowered to the second agglomeration of cells at the staging support. [0032] FIG. 14 is the embodiment of the device of FIG. 13 , wherein the gripper has been raised while gripping and lifting the second agglomeration of cells off of the staging support. [0033] FIG. 15 is the embodiment of device of FIG. 14 , wherein the gripper has been rotated about a vertical axis to bring the second aggregation of cells within the proximity of the build support and the first aggregation of cells. [0034] FIG. 16 is the embodiment of the device of FIG. 15 , wherein the assembly vessel has been moved in a horizontal plane to align the gripper and second aggregation of cells within the build support and first aggregation of cells. [0035] FIG. 17 is the embodiment of the device of FIG. 16 , wherein the gripper and the second aggregation of cells have been lowered vertically to bring the second aggregation of cells into contact with the first aggregation of cells. [0036] FIG. 18 is the embodiment of the device of FIG. 17 , wherein the gripper has been vertically raised to leave the second aggregation of cells on the first aggregation of cells, thereby forming an assembly of aggregations of cells of the invention. [0037] FIG. 19 is a perspective view of an assembly of aggregations of adherent cells of one embodiment of the invention. Stacking and alignment of honeycomb-shaped parts creates channels for perfusion. [0038] FIG. 20 is a perspective view of one embodiment of an assembly aggregation of cells of the invention that includes rod-shaped building parts that define channels for perfusion. [0039] FIGS. 21A-21D are photographs of different views of an embodiment of a gripper suitable for use in the device of the invention. The gripper includes a round membrane (dia 12 mm, 3 μm pores). The different views show membrane gripping surface ( FIG. 21A ) and side view of capped polystyrene cylinder with connector for pump tubing ( FIG. 21D ). [0040] FIG. 22 is a photograph of another embodiment of the device of the invention. Shown is the bio-gripper head held in place by a manual x, y, z micromanipulator positioned over the objectives of an inverted microscope. The bio-gripper head (or gripper) is immersed in the cell culture medium of the build area (lid removed) and is attached to a peristaltic pump that creates controllable fluid suction to grip and dispense microtissues (aggregations of adherent cells). A microtissue to be gripped is positioned under the bio-gripper by moving the build area using the x, y (horizontal) microscope stage. The bio-gripper is then lowered along its z (vertical) axis to contact the microtissue and fluid suction grips the microtissue to the membrane. The bio-gripper with attached microtissue is retracted and the microscope stage moved to the target. The bio-gripper is lowered and fluid flow reversed to dispense the microtissue on its target. [0041] FIG. 23 is a series of photographs of live/dead staining of control ( FIGS. 23A-23C ) and gripped ( FIGS. 23D-23F ) H35 spheroids. Scale bar 100 microns. [0042] FIGS. 24A-24D are photographs of live/dead staining of ungripped control ( FIGS. 24A , 24 B) and gripped ( FIGS. 24C , 24 D) KGN toroids, 25,000 cells/toroid. Scale bar 200 microns. [0043] FIGS. 25A-25D are photographs of live/dead staining of ungripped control ( FIGS. 25A , 25 B) and gripped ( FIGS. 25C , 25 D) KGN toroids, 30,000 cells/toroid. Scale bar 200 microns. [0044] FIGS. 26A-26D are photographs of live/dead staining of gripped KGN toroids after fusion; FIGS. 26A , 26 B 30 , 000 cells/toroid, FIGS. 26C , 26 D 40 , 000 cells/toroid. Scale bar 500 microns. [0045] FIG. 27 is a photographic (Brightfleld) image of four KGN toroids stacked on a 330-micron outer diameter capillary tube. Scale bar 300 microns. [0046] FIGS. 28A-28E are photographic grayscale brightfield side view images of a toroid stack around a 170-micron outer diameter capillary tube, demonstrating fusion of individual toroids into a single tissue over time (FIG. 28 A=0 hrs, FIG. 28 B=12 hrs, FIG. 28 C=24hrs, FIG. 28 D=48 hrs, FIG. 28 E=72 hrs). Scale bar 500 microns. This is new data not in original filing. Attached is the figure from our manuscript we are submitting, below is the figure legend. [0047] FIGS. 29A-D are a series of photographs illustrating formation of an aggregation of cells employed as a building part in another example of the invention. [0048] FIGS. 30A-E are a series of photographs representing assembly of building-part honeycomb microtissues (comprised of 250,000 MCF-7 cells) that were picked, placed, and stacked onto a build head by the method of the invention. Close-up overhead photos of a building sequence show a stack of two, three, and four honeycombs ( FIGS. 30A , B and C, respectively). A close-up side view photo of a stack of three honeycombs on the build head is shown at the bottom left ( FIG. 30D ). An angled top view photo of stack of three honeycombs on a build head is shown on bottom right ( FIG. 30E ). The approximate time to stack four honeycombs was 15 minutes. DETAILED DESCRIPTION OF THE INVENTION [0049] The invention generally is directed to a device and method for assembly aggregation of adherent cells. The invention is also directed to three-dimensional assemblies adherent cells. [0050] FIG. 1 (Prior art) is one embodiment of aggregations of adherent cells according to the method of the invention, employing a device of the invention. Specifically, shown in FIG. 1 is an orbital honeycomb of about six times ten to the sixth cells formed in a micro-mold and stained for viability after 24 hours. The viable cells are shown in green. Dead cells are shown in red. The image shown is the emerged red and green fluorescent stitched image. [0051] In another embodiment, shown in FIG. 2 (Prior art), the aggregation of inherent cells is in the form of a toroid, as shown in FIG. 2 , of about 20,000 cells each, which undergo fusion in all directions. FIG. 2 is an image of two self-assembled toroids placed adjacent on flat non-adhesive agarose fused in a plane. The images are shown at days 0,2,4 ( FIGS. 2A through 2C ). [0052] Aggregations of cells, such as are shown in FIGS. 1 and 2 , that are suitable for use in by the device and in the method of the invention, can be formed by a method known in the art, such as is described, for example, in U.S. Pat. No. 8,361,781 B2, issued Jan. 29, 2013, by Morgan et al., the entire teachings of which are incorporated herein by reference. [0053] Examples of suitable cells for use by the device and the method of the invention include many different cell types including but not limited to primary cells including hepatocytes, cardiomyocytes, kidney cells, pancreatic cells, fibroblasts, myocytes, epithelial cells, corneal epithelial cells, stromal cells, stem cells, induced pluripotent stem cells, smooth muscle cells, muscle cells, chondrocytes, neural cells, ligament cells, tendon cells, ovarian cells, thyroid cells, parathyroid cells, and also many different kinds of cell lines including but not limited to MCF-7 cells, KGN cells, HEK cells, 3T3 fibroblasts, HepG2 cells, HepG2C3A cells, H35 cells. [0054] One embodiment of a device of the invention for assembling aggregations of adherent cells is shown in schematic form in FIG. 3 . As shown therein, FIG. 3 includes device 10 of the invention for assembling aggregations of adherent cells. Device 10 includes assembly vessel 12 defining inlet 14 and outlet 16 . A suitable material of construction of assembly vessel can include, for example, plexiglass. In one embodiment, assembly vessel 12 is formed of plexiglass. In a specific embodiment, assembly vessel 12 is transparent. Assembly vessel 12 is in fluid communication with perfusate source 18 at inlet 14 and outlet 16 through conduits 20 , 22 , respectively. Perfusate pump 24 at conduit 20 is employed to control the rate of recirculation of perfusate 26 through assembly vessel 12 and perfusate source 18 . Perfusate source 18 is a suitable source of perfusate to sustain the aggregations of cells within assembly vessel 12 , such as is known in the art. Examples of suitable perfusates recirculated through perfusate source include, for example, cell culture medium such as DMEM Dulbecco's Modified Eagles' media, all of which, are well known in the art. In another embodiment, not shown, pumps are employed to recirculate perfusate through components within assembly vessel without use of a separate perfusate source vessel. [0055] Gripper 28 within assembly vessel 12 includes gripper housing 30 defining gripper chamber 32 and at least two openings 34 , 36 . Suitable materials of construction of gripper housing include, for example, polystyrene and glass. Gripper membrane 38 is affixed over an opening 36 , as shown in FIG. 1 . Examples of suitable membranes for use as gripper membrane at gripper housing 30 include, Millicell cell culture inserts (EMD Millipore, Billerica, Mass.) (12 mm diameter, 10 mm height), which have a polycarbonate membrane with track-etched 3-micron (gripper) or 8-micron (build) pores. Also those versed in the art will know there are other porous membranes as well as porous structures besides membranes that can be used to grip tissues. In one embodiment, gripper membrane 38 has a pore size diameter of about 3 μm and a pore density of about 2×10 6 pores/cm 2 . In another embodiment, the pore size diameter is about 8 μm and a pore density of about 1×10 5 pores/cm 2 . Gripper housing 30 is supported by support 40 at gripper housing 30 . In the embodiment shown in FIG. 3 , support 40 also operates as a conduit extending from opening 34 of gripper housing 30 and provides fluid communication between chamber 32 defined by gripper housing 30 and perfusate source 18 through conduit 42 , and pump 44 . Optionally, three-way valve 46 , which is controlled by controller 48 at the intersection of conduits 40 , 42 and 50 , is included and provides an option for reversing the flow of perfusate through conduit 40 by terminating flow through conduit 42 and pump 44 , and opening fluid communication between perfusate source 18 and gripper 28 through conduit 50 and pump 52 . Alternatively, when the pump is a peristaltic pump, or positive displacement pump, manifold and three-way valve are not needed, and flow is reversed at conduit by simply reversing the operation of the pump. [0056] Conduit 40 is fixed to micromanipulator 54 which, in turn, is supported by post 56 mounted to rigid external support 58 . Micromanipulator 54 is controlled by controller 48 and, upon actuation by controller 48 , rotates about post 56 , thereby causing rotation of gripper 28 about major longitudinal axis 60 extending through post 56 . Micromanipulator 54 , also upon actuation of controller 48 , is movable along major longitudinal axis 60 of post 56 , thereby raising and lowering gripper 28 within assembly vessel 12 . Visualization device 62 , such as a microscope at conduit 40 is directed toward gripper 28 and, by virtue of transparency of the material of gripper housing 30 and gripper membrane 38 , images aggregations of cells within assembly vessel 28 and below gripper membrane 38 . Visualization device 62 is operated by controller 48 . Visualization device 62 will move with movement of conduit 40 supporting gripper 28 . Alternatively, or optionally, in another embodiment, not shown, at least one visualization device is located at at least one of a transparent bottom or side of assembly vessel 12 . [0057] Staging support 64 is fixed within assembly vessel 12 at bottom portion 66 of assembly vessel 28 . Staging support 64 includes staging housing 68 defining staging chamber 70 and at least two openings 72 , 74 . Staging membrane 76 extends over and seals opening 72 of staging housing 68 . Staging membrane 76 can be of the same or a different type of material or porosity than the gripper membrane. Conduit 78 extends from other opening 74 of staging housing 68 and through pump 80 to perfusate source 18 . The material of construction of staging housing 68 and staging membrane 76 can be the same as that of gripper 28 , although they need not be transparent. Optionally, rigid support or mold, not shown, is fixed to staging membrane 76 in order to assist in retaining an aggregation of cells at staging membrane 76 . [0058] Build support 82 is fixed within assembly vessel 12 , as is staging support 64 . Build support 82 includes build housing 84 defining build chamber 86 and at least two openings 88 , 90 . Build membrane 92 extends over and seals opening 88 of build housing 84 . Suitable membranes include those employed as the gripper membrane, such as a membrane having a pore size diameter of about 8 μm and a pore density of about 1×10 5 pores/cm 2 . The build membrane can be of the same or different type of material or porosty than the gripper membrane and the staging membrane. Conduit 94 extends from another opening 90 of build housing 84 and extends through pump 96 to perfusate source 18 . Optionally, rigid support or mold (not shown) is fixed at build membrane 92 to assist in support of an aggregation of cells at build membrane 92 . Preferably, staging membrane 76 and build membrane 92 are in a common plane. Preferably the common plane in which support membrane 76 and build membrane 92 lie is transverse to and, most preferably, normal to the major longitudinal axis 60 of post 56 extending from support 58 . [0059] Assembly vessel support 98 is fixed to assembly vessel 12 . Assembly vessel support 98 controls movement of assembly vessel 12 in a plane essentially normal to major longitudinal axis 60 of post 56 extending from support 58 . The position of assembly vessel 12 by virtue of assembly vessel support 98 is controlled by controller 48 . [0060] In one embodiment of the invention, device 10 of the invention represented in FIG. 3 is employed to conduct an embodiment of the method of the invention by moving aggregations of cells resting on one or more staging supports 64 within assembly vessel 12 to build support 82 to thereby obtain a stack of aggregations of adherent cells on build support 82 . In one embodiment, the method of the invention includes the following steps. [0061] Aggregation of cells 100 is deposited on staging membrane 76 . In one embodiment, assembly vessel 12 contains a plurality of staging supports 64 , each of which support at a respective staging membrane 76 at least one aggregation of cells. Aggregations of cells are either deposited at staging membranes or grown at staging membranes by a suitable method, such as is described in U.S. Pat. No. 8,361,781 B2, issued Jan. 29, 2013, by Morgan et al., the entire teachings of which are incorporated herein by reference in their entirety. The rate of perfusate flow across aggregation of cells 100 at staging membrane 76 by direction of perfusate 26 from assembly vessel 12 through staging membrane 76 and into staging support 64 is sufficient to sustain aggregation of cells 100 with nutrients and oxygen. Alternatively, aggregation of cells 100 is not supported by staging support 64 , but, rather, is grown in a separate vessel (not shown) and transferred to assembly vessel by a suitable means, wherein they lie essentially randomly at the bottom of assembly vessel 12 . In this latter embodiment, visualization device 62 and gripper 28 can be employed to locate and then selectively secure individual aggregations of cells to gripper membrane 38 for transfer to build support 82 . [0062] Returning to the method employed by the apparatus shown in FIG. 3 , visualization device 62 is employed to identify aggregation of cells 100 lying on staging membrane 76 within assembly vessel 12 by use of controller 48 . Once identified, support 40 , including visualization device 62 and gripper 28 , are lowered by actuation of micromanipulator 54 to cause movement of micromanipulator 54 along major longitudinal axis 60 of post 56 by controller 48 until gripper membrane 38 is adjacent to aggregation of cells 100 at staging membrane 76 , as shown in FIG. 4 . [0063] Perfusate 26 is directed from assembly vessel 12 through gripper membrane 38 and conduit 40 , 42 by actuation of pump 44 , whereby perfusate 26 is directed from gripper housing 30 through conduits 40 , 42 and pump 44 to perfusate source 18 causes a direction of flow of perfusate 26 through gripper membrane 38 at a rate and velocity that is greater than that of perfusate 26 directed through staging membrane 76 into staging housing 68 and pump 80 back to perfusate source 18 . As a consequence, aggregation of cells 100 will preferentially be directed toward gripper membrane 38 . The rate of flow of perfusate 26 is sufficient to sustain the aggregation of cells 100 at gripper membrane 38 . [0064] As shown in FIG. 5 , micromanipulator 54 is actuated by controller 48 to thereby cause micromanipulator 56 to move upward along major longitudinal axis 60 of post 56 , causing gripper 28 , in turn, to move away from staging membrane 76 while aggregation of cells 100 remains at gripper membrane 38 , thereby raising aggregation of cells 100 away from staging membrane 76 . [0065] As shown in FIG. 6 micromanipulator 54 is then rotated about major longitudinal axis 60 of post 56 by operation of controller 48 , thereby also causing gripper 28 and visualization device 62 to rotate about major longitudinal axis 60 of post 56 , whereby gripper 28 and aggregation of cells 100 at gripper membrane 38 are brought into relatively close proximity to build support 82 . [0066] As shown in FIG. 7 , assembly vessel support 98 is actuated by use of visualization device 62 and controller 48 to bring aggregation of cells 100 into alignment with build membrane 92 . Assembly vessel support 98 , as stated above, operates to move build membrane 92 in a plane that is transverse to and, preferably, normal to major longitudinal axis 60 of post 56 about which gripper 28 rotates by actuation of micromanipulator 56 . [0067] As shown in FIG. 8 , micromanipulator 54 is then actuated to move along the major longitudinal axis 60 of post 56 , thereby lowering visualization device 62 and gripper 28 until aggregation of cells 100 is adjacent build membrane 92 . Perfusate 26 is directed from assembly vessel 12 through build membrane 92 and through build support housing 84 and conduit 94 by pump 96 back to perfusate source 18 at a rate sufficient to cause aggregation of cells 100 to be retained at build membrane 92 . The rate of flow of perfusate from assembly vessel 12 across aggregation of cells 100 and build membrane 92 into build housing 84 is also sufficient to sustain the cells with sufficient nutrients and oxygen. [0068] Three-way valve 46 is then actuated to terminate flow of perfusate 26 from assembly vessel 12 through gripper membrane 38 and gripper housing 30 , thereby terminating the force of flow through gripper membrane 38 that causes adherence of aggregation of cells 100 to gripper membrane 38 . Optionally, three-way valve 46 is actuated to provide fluid communication between conduit 50 and pump 52 , thereby reversing the flow of perfusate 26 so that, rather than perfusate 26 being directed from gripper 28 through perfusate source 18 , perfusate 26 is directed from perfusate source 18 through pump 52 , three-way valve 46 and gripper 28 into assembly vessel 12 , providing a direction of flow that directs aggregation of cells 100 away from gripper membrane 38 . Alternatively, when a peristaltic, or positive displacement valve is employed, a three-way valve is not necessary, and flow through conduit can be stopped or reversed simply by stopping or reversing operation of the peristaltic or positive displacement pump. [0069] As can be seen in FIG. 9 , micromanipulator 54 is then actuated to move along longitudinal axis 60 of port 56 , thereby raising visualization device 62 and gripper away 28 from build support 82 , leaving aggregation of cells 100 at build membrane 92 . At this time, if not already done, three-way valve 46 , or other suitable means, depending on the type of pump employed, can be actuated to terminate flow of perfusate 26 from perfusate source 18 to gripper 28 , if the three-way valve 46 is set to cause perfusate to be so directed. [0070] As shown in FIG. 10 , assembly vessel support 98 is then actuated to move assembly vessel 12 and, consequently, staging support 64 and build support 82 , in a plane essentially transverse to the longitudinal axis 60 of post 56 . As shown in FIG. 11 , micromanipulator 54 is actuated to cause rotation of micromanipulator 54 about the major longitudinal axis 60 of post 56 , thereby aligning gripper membrane 38 with staging support 64 . [0071] As shown in FIG. 12 , the next, or second, aggregation of cells 102 , either by prior placement of second aggregation of cells 102 on staging support 69 previously employed, or by actuation of assembly vessel support 98 , is vertically aligned with assistance of visualization device 62 with gripper membrane 38 . [0072] As shown in FIG. 13 , gripper 28 and, thereby, gripper membrane 38 are lowered by actuation of micromanipulator 54 to cause gripper membrane 38 to contact second aggregation of cells 102 at staging membrane 76 . Three-way valve 46 , or other suitable valve, depending on the type of pump used, is then actuated to cause perfusate 26 to be directed from assembly vessel 12 through gripper membrane 38 and gripper housing 30 through conduits 40 , 42 and pump 46 to perfusate source 18 at a rate greater than the rate at which perfusate 26 is directed through staging membrane 76 , pump 80 and conduit 78 to perfusate source 18 , thereby causing second aggregation of cells 102 to preferentially adhere to gripper membrane 38 . Also, the rate at which perfusate 26 is directed across second aggregation of cells 102 and gripper membrane 38 is sufficient to sustain second aggregation of cells 102 . [0073] As shown in FIG. 14 , micromanipulator 54 is then actuated to raise gripper 28 , with second aggregation of cells 102 adhering to gripper membrane 38 , away from staging membrane 76 . Micromanipulator 54 is then actuated to rotate about the major longitudinal axis 60 of post 56 , to thereby bring gripper 28 and second aggregation of cells 102 within the proximity of first aggregation of cells 100 previously deposited at build membrane 92 , as shown in FIG. 15 . Assembly vessel support 98 is then actuated to cause alignment, with the assistance of visualization device 62 and controller 40 , of first aggregation of cells 100 at build membrane 92 with second aggregation of cells 102 at gripper membrane, as shown in FIG. 16 . [0074] Gripper 28 , with second aggregation of cells 102 , is then lowered until second aggregation of cells 102 is contacting first aggregation of cells 100 , as shown in FIG. 17 . [0075] Three-way valve 46 , or another type of valve, as appropriate, is then actuated again, as described previously, with respect to the first aggregation of cells 100 placed at build membrane 92 and, as shown in FIG. 18 . Alternatively, pump 44 is shut off. In either case, second aggregation of cells 102 is released from gripper membrane 38 , or drawn away from gripper membrane 38 by flow of perfusate 26 directed across second aggregation of cells 102 , first aggregation of cells 100 , and build membrane 92 into build support chamber 86 and back to perfusate source 18 . Gripper 28 is then raised, leaving second aggregation of cells 102 upon first aggregation of cells 100 , thereby assembling aggregations of cells 104 in a stack on build support 82 . [0076] The above process is then repeated to build a stack of aggregations of cells 104 at build support 82 until a suitable number of aggregations of cells have been assembled on build support 82 . The number of aggregations of cells assembled on build support 82 is indefinite. For example, one strategy is to define the minimum number that defines a stack which is two, such as for an artificial cornea. Another embodiment, for example, would be building a liver for humans. The human liver has about 240 billion cells. A large honeycomb part may have close to 10 million cells, so to build a liver would require picking and placing about 24,000 parts of this size. Larger parts would mean fewer stacks. A third embodiment would be to build a “mega” organ not for transplantation but rather for the in vitro synthesis and secretion of valuable products, such as recombinant proteins. These man-made mega organs would be like bio-manufacturing facilities and so could have even more stacks. [0077] Following assembly of a suitable number of layers of aggregations of cells, the assembly can be removed from assembly vessel 12 for suitable use. Alternatively, the assembly of aggregations of cells 104 can remain within vessel and perfused by perfusate that is conducted through assembly of aggregations of cells 104 , such as through openings defined by the aggregations of cells 104 assembled on build support 82 through build support housing 84 and back to perfusate source 18 , thereby allowing the assembly of aggregations of cells 104 to remain in place by virtue of the flow of perfusate 26 from assembly vessel 12 through build support 82 and providing sufficient nutrients to maintain the assembled aggregations of cells 104 for a period of time sufficient to cause the assembly of aggregations of cells 104 to fuse. The fused assembly of aggregations of cells 104 can then be removed from assembly vessel 12 for subsequent processing and use, such as surgical use as tissue. [0078] In one embodiment, the assembly of aggregations of cells 104 is conducted in a manner to cause openings defined by the aggregations of cells to substantially align. In another embodiment, the aggregations of cells are stacked in a manner that does not cause the openings defined by each aggregation of cells to be aligned. In a still further embodiment, different shapes of aggregations of cells are assembled to thereby cause formation of a stack of aggregations of cells that assumes a three-dimensional character, such as that of a frustum, pyramid, or other three-dimensional shape (not shown) that, upon fusion of the layers of aggregations of cells assembled, will form a unitary three-dimensional tissue suitable for use as, for example, replacement tissue of a body part. [0079] FIG. 19 shows a schematic of how vascular channels are formed when honeycomb parts are stacked. Alternatively, as shown in FIG. 20 , vascular channels can be created by cross stacking building parts in the shape of rods as described. Flow rates of Q=1 cm 3 /min are sufficient for griping the structures without any damage. Where permeability of membrane is k=nπd 4 /128=6×10 −10 cm 2 , for example, the pressure drop across the membrane is estimated to be ΔP=QμL/kA=102 Pa. Hence, negative pressures of about 100 Pa typically are enough to grip H35 spheroids. These pressure drops not enough to induce rupture of the microtissues. [0080] The device and method of the invention will now be demonstrated by the following experimental demonstration, which is not intended to be limiting in any way. EXEMPLIFICATION Example 1 Materials and Methods Micro-Molded Hydrogels and Microtissue Formation [0081] Agarose gels were cast from 3D Petri Dish® micro-molds (Microtissues, Inc., Providence, R.I.). Powder UltraPure™ Agarose (Invitrogen, Carlsbad, CA) was sterilized by autoclaving and dissolved via heating in sterile water to 2% (weight/volume). Molten agarose was pipetted into each micro-mold and air bubbles were removed by agitation with a sterile spatula. After setting, gels were separated from the micro-mold using a spatula, transferred to twelve-well tissue culture plates, and equilibrated for at least 4 hours with several changes of culture medium. Micro-molds with two different recess geometries were used to produce agarose gels to create spheroid or toroid microtissues. Round recesses for spheroids were 800 μm in diameter and contained 81 recesses per gel. Toroidal recesses were 1400 μm in diameter with a central agarose peg of 600 μm and contained 36 features per gel. [0082] Rat hepatoma (H35) and human ovarian granulosa (KGN) cells were expanded in Dulbecco's Modified Eagle Medium (DMEM) (Invitrogen) supplemented with 10% fetal bovine serum (FBS)(Thermo Fisher Scientific, Waltham, Mass.) and 1% penicillin/streptomycin (Sigma-Aldrich, St. Louis, Mo.). Cultures were maintained in a 37° C., 10% CO 2 atmosphere. Cells were trypsinized, counted, and re-suspended to the desired cell density for each experiment. 190 μL of cell suspension was pipetted into the rectangular seeding chamber above the recesses of each micro-molded agarose gel. Spheroid gels were each seeded at a concentration of 1,250 cells per spheroid feature. Toroid gels were each seeded at concentrations varying from 25,000 to 35,000 cells per toroid feature. Samples were then incubated for approximately twenty minutes to allow cells to settle into recesses before 2 mL of medium was slowly added to each well. Medium was exchanged every other day. Live-Dead and Cell Tracker Staining [0083] For Live-Dead staining, microtissues were incubated with a mixture of 2 mL phosphate-buffered saline (PBS) with 4 μM of ethidium homodimer-1 and 1 μM calcein AM (Invitrogen) for 75 minutes at 37° C. Microtissue viability was assessed via fluorescent imaging using a Zeiss Axio Observer Z1 equipped with an AxioCam MRm camera with AxioVision Software (Carl Zeiss Micro-Imaging, Thornwood, N.Y.) and an X-Cite 120 fluorescence illumination system (EXFO Photonic Solutions, Ontario, Canada). [0084] For Cell Tracker staining, cells were washed with serum-free medium and incubated for 45 minutes in either DMEM with 5 μM CellTracker™ Green (Invitrogen) or DMEM with 5 μM CellTracker™. Plates were washed with PBS and the labeled cells were trypsinized, counted and seeded into micro-molds to form labeled microtissues. Fabrication of Device Instrument [0085] The bio-gripper head of the device instrument, shown in FIGS. 21A-21D was fabricated using a Millicell cell culture insert (EMD Millipore, Billerica, Mass.) (12 mm diameter, 10 mm in height) with a polycarbonate membrane with track-etched 3-micron pores. The three small feet on the bottom of the cylindrical insert were removed. A 4-mm hole was drilled into the side of the insert and a polypropylene elbow joint fitting (2.4 mm ID)(Cole-Parmer Instrument Co., Chicago, Ill.) was connected using plastic cement (The Testor Corp., Rockford, Ill.). The top or open end of the insert was sealed with a standard 18 mm circular micro cover glass (VWR Scientific, Inc., West Chester, Pa.) using epoxy (ITW Devcon, Danvers, Mass.). The elbow joint was connected to a segment (14 cm) of stiff polystyrene tubing that was attached to a manual x, y, z micromanipulator (Narishige, Nikon, Japan) mounted on a Nikon Diaphot inverted microscope with manual x, y stage control and its condenser removed. The bio-gripper's micromanipulator was mounted directly above and in line with the objectives. The other end of the polystyrene tube was fitted with a male-male tubing joint that was connected to tubing run through a Multistaltic® peristaltic pump (Haake Buchler Instruments, Inc., Saddle Brook, N.J.) capable of reversible flow rates up to 2 mL/minute. The other end of the tubing was placed into the build chamber, a 150-mm Petri dish containing cell culture medium, thus creating a closed system for recirculation of culture medium during operation of the device. [0086] The device was operated as follows. Microtissues (spheroids or toroids) released from their micro-molds were deposited into the build chamber and brought into view using the microscope's x, y stage. The bio-gripper head, submerged in cell culture medium, was lowered down onto the microtissue. Proximity of microtissue and the membrane of the gripper head were evident when both were in focus. The peristaltic pump was run at 1 mL/min to grip tissues. After gripping, the bio-gripper head was raised, with both the microtissue of interest and the membrane moving out of focus. [0087] To place the microtissues, the microscope's x, y stage was adjusted so that the intended target was brought into position under the bio-gripper head with gripped microtissue. The head was lowered, and when it had reached the appropriate distance on the z-axis, flow across the membrane was reversed to facilitate release of the microtissue. Bio-gripper heads were exchanged with each experiment to mitigate the effect of membrane clogging from debris. Side-views of the microtissue being lowered onto its target were obtained using a dissecting microscope mounted perpendicular to the z-axis and was useful for more precise control of the distance between gripped microtissue and target. Instrument Fabrication [0088] To build a manually operated device instrument, the condenser of an inverted microscope was removed and mounted directly above the objectives an x, y, z micromanipulator holding a bio-gripper head ( FIG. 22 ). The bio-gripper head was fabricated from a cylindrical polystyrene cell culture insert with a membrane (3 μm diameter pores). The insert top was capped off with a glass coverslip and a side port added to attach tubing ( FIGS. 21A-21D ). The controllable fluid suction force of the bio-gripper head was created by the action of a peristaltic pump pulling culture medium through the membrane. The porous membrane (of area A=πD 2 /4=0.6 cm 2 , pore size d=3 μm, thickness L=22 μm and pore density n=3×10 6 pores/cm 2 ) was transparent when wet enabling visualization of the microtissue when gripped. Permeability of the membrane was approximately k=nπd 4 /128=6×10 −10 cm 2 , and the pressure drop across the membrane at low flow rates (Q=1 cm 3 /min) were estimated to be Δp=QμL/kA=102 Pa. The bio-gripper head was a modular piece that was easily exchanged and could be custom designed for microtissues of varying sizes and shapes Gripped Microtissues Were Viable [0089] To determine if gripping altered the viability of microtissues, H35 spheroids (1250 cells/spheroid) were gripped, moved and dispensed into dishes coated with agarose to prevent spheroid adhesion. Control ungripped spheroids were kept in parallel dishes and subjected to all the same treatments except gripping. Spheroids were then stained with Live/Dead ( FIG. 23A-23F ). From these images, there was no significant difference in the viability between gripped and non-gripped spheroids. [0090] To determine if larger more complex structures could be gripped, toroids of KGN cells (25,000, 30,000, and 35,000 cells/toroid) were made. The toroids were loaded into the build area, gripped and deposited into an agarose coated culture dish submerged in the build area. Control (non-gripped toroids) and gripped toroids were stained Live/Dead ( FIGS. 23A-23F , 24 A- 24 D). There was no breakage of the toroid structure and there were no differences in viability between gripped and control toroids at any of the seeding densities tested. [0091] Large Sheets of Toroids Were Formed and Gripped: [0092] To determine if the device could safely manipulate even larger more complex microtissues, sheets of fused toroids were formed. After 15 hours of self-assembly, toroids (˜30,000 to 40,000 cells/toroid) were released from their micro-molds into 60-mm dishes that had been coated with agarose. After the toroids settled, the dishes were tilted causing the toroids to collect on one side of the dish and contact each other. Twenty four later, the toroids had fused into a contiguous sheet of toroids. Gripping, moving and releasing these sheets did not fracture the sheet or alter its viability ( FIGS. 25A-25D ). The same flow rate (1 mL/min) was used to grip individual microtissues and the sheet of toroids. During the fusion process, the lumens of the toroids narrowed, less so for the toroids with 30,000 cells versus 40,000 cells. [0093] Toroids Were Stacked: [0094] To test the ability of the device to stack toroids, KGN toroids (35,000 cells/toroid) were gripped and then released over small diameter capillary tubes (330 or 170 μm outer diameter) embedded in and protruding upward from agarose. One at a time, toroids were gripped and transported so that their lumens were aligned in the x, y plane with the outer diameter of the capillary tubes. The z distance between the bio-gripper's membrane and the end of the capillary tube was approximated by observing the capillary tube catching the toroid as the tube was moved in the x, y plane relative to the toroid. Upon alignment, the toroid was released by reversal of flow through the membrane. Careful approximation of the membrane and the capillary tube in the z direction minimized occurrences of the toroid not successfully being released onto the capillary tube. By repeating this procedure, an initial stack of toroids was placed around the large diameter capillary tube ( FIG. 26 ). The procedure was repeated with the smaller diameter capillary tube (170 μm) and taller stacks were made containing up to 16 toroids. Manual stacking of each toroid required less than 5 minutes. Stacked toroids were incubated at 37° C. and side view images taken to determine if the stacked toroids fused ( FIG. 27 ). Over time, the toroids fused as shown by the closing of small gaps and the melding and flattening of the round edges of the toroids. The stack of toroids also contracted their lumens and appeared to attach to the capillary tube. The height of the stack of 16 toroids is greater than 3.5 mm. FIGS. 28A-28E show different toroid stacks formed by the method of the invention. Example 2 [0095] Honeycombs were gripped and stacked to determine if a device of the invention (“Bio-P3”) could handle even larger and more complex building parts, we prepared multi-cellular honeycombs were prepared ( FIGS. 29A-D ). Shown in FIGS. 29A-D are photographs of a micro-mold ( FIG. 29A ) and a micro-molded agarose gel prepared from mold ( FIG. 29B ). After equilibration in cell culture medium, micro-molded agarose gel was seeded with 250,000 MCF-y cells that self-assembled a multi-cellular honeycomb structure in the gel within 24 hours ( FIG. 29C ). The cells were harvested 48 hours after seeding. Brightfield image of multi-cellular honeycomb with seven lumens after release from the gel is shown in FIG. 29D . Scale bar 500 microns. The method of preparation of multicellular honeycombs is more completely described in U.S. Pat. No. 8,361,781, the teachings of which are incorporated by reference in their entity. Honeycomb microtissues were introduced into the holding pen of the Bio-P3 instrument. They were subsequently gripped one at a time, moved into position and deposited onto the build head ( FIG. 30 ). A stack of four honeycombs was assembled, with fair alignment of lumens through the four tissues. FIGS. 30A-E are a series of photographs representing assembly of building-part honeycomb microtissues (comprised of 250,000 MCF-7 cells) that were picked, placed, and stacked onto a build head by the method of the invention. Close-up overhead photos of a building sequence show a stack of two, three, and four honeycombs ( FIGS. 30A , B and C, respectively). A close-up side view photo of a stack of three honeycombs on the build head is shown at the bottom left ( FIG. 30D ). An angled top view photo of stack of three honeycombs on a build head is shown on bottom right ( FIG. 30E ). The approximate time to stack four honeycombs was 15 minutes. This most directly demonstrates the potential of the Bio-P3 device, to assemble a large (>2 mm in smallest dimension), multi-lumen, high-density (˜1 million cells total) tissue construct. [0096] The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety. [0097] While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.	A device for assembling aggregations of adherent cells includes a gripper moveable within an assembly vessel that fixes aggregations of adherent cells at a membrane of the gripper and, by movement of the gripper, assembles aggregations of cells on a separate membrane within the vessel, thereby creating a three-dimensional assembly of aggregations of cells that fuse and can be employed in surgical procedures as a unitary tissue of adherent cells. The aggregations of cells, as assembled, can assume three-dimensional configurations distinct from any one of the component aggregations of cells assembled.	2
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of co-pending U.S. application Ser. No. 12/346,958 filed Dec. 31, 2008, the entire disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an image processing apparatus serving as a complex peripheral apparatus handling image data as cores to be processed, such as an MFP (Multifunctional Peripheral) having plural functions and, more particularly, to an image processing apparatus capable of processing information such as image data in use of an external memorizing device detachably attached thereto. 2. Description of the Related Art High speed and multi-functions are required for digital photocopiers these days, and digital hybrid machines come to be sold in market in which the machines have a scanner function, a facsimile function, and a printing function in addition to a photocopying function. A single high speed printer may be used via LAN connections in share with a relatively large number of people for word processing or image processing in, such as, e.g., factories or companies. Where a user employs the scanner function of such as a digital photocopier, the user can process the image data read out of an original document using each user's personal computer connected via the LAN connection. For off-line processing in a personal computer not connected with the LAN, an art has been known in which image data read with a scanner function are stored temporarily in an external memorizing device such as, e.g., a memory card to be processed and in which a user easily can work upon bringing the image date with such an external memorizing device into a laptop type computer not connecting with the LAN after writing the data in the external memorizing device thus detachably attached (see, e.g., Japanese Unexamined Patent Publication No. 2004-72762). The user, however, can always attach and detach the external memorizing device such as a memory card, and may detach the external memorizing device even during a period in a processing of writing information such as image data into the external memorizing device. In such a case, the data under writing may be damaged, resulting in failures of writing processing. Similar problems may occur in situations that the apparatus is turned off accidentally or by itself for some reasons. Files failed in writing frequently cannot be open on the application because those files are not yet completed as proper files, and such failed files become apparently useless for users. To delete such useless files, the user has to connect the external memorizing device including the failed files with an apparatus, such as, e.g., a personal computer having a function deleting files and manually has to execute deletion of writing failed files after searching such failed files, and therefore, the user's work would become burdensome. A user may not be aware of existence of writing failed files, and if the user does other jobs as remaining those writing failed files in the external memorizing device, the failed files may depress an empty capacity of the device, thereby possibly rendering the device unable to store necessary files. It is an object to provide an image processing apparatus capable of proceeding to subsequent jobs without being bothered with recovery work for users even where writing failed files are remained in such an external memorizing device. BRIEF SUMMARY OF THE INVENTION The foregoing objects are accomplished with an image processing apparatus comprising: an information retrieving unit for retrieving writing processing information out of an external memorizing device detachably attached thereto storing the writing processing information; and an information deleting unit for deleting information corresponding to the information retrieved from the information retrieving unit. According to an aspect of the invented image processing apparatus, the image processing apparatus is provided to include the information retrieving unit for retrieving writing processing information out of the external memorizing device, and the image processing apparatus turns out as to whether certain information is in a processing of writing by retrieving the writing processing information out of the external memorizing device. If it is turned out that the status is in a processing of writing, the corresponding information is automatically deleted. A user is not necessary to delete the writing failed file manually, so that the user's work load will be reduced. In a preferred embodiment of the invented image processing apparatus, the image processing apparatus is provided to include an information display unit for displaying information corresponding to the information retrieved from the information retrieving unit. The image processing apparatus may includes an information writing unit for writing information to the external memorizing device, wherein the information writing unit writes information indicating a status in processing of writing with respect to the writing processing information before writing of the information, and changes the status from in processing of writing to in not processing of writing after completion of writing of the information. Another image processing apparatus according to the invention, includes: an original document reading unit for reading an original document; an internal memorizing device installed within an apparatus housing; an information writing unit for writing data read at the original document reading unit to an external memorizing device detachably attached to the apparatus housing; an attaching detaching detection unit for detecting attachment and detachment of the external memorizing device; and an instructing unit for stopping, when the external memorizing device is detached from the apparatus housing, writing the data read to the external memorizing device at the information writing unit and making an instruction for writing a remainder of the data read into the internal memorizing device, wherein the information writing unit reads out the data written in the internal memorizing device and rewrites the data in the external memorizing device when the external memorizing device is detected as attached to the apparatus housing. According to the image processing apparatus, the external memorizing device is configured so that detachment thereof is detected by the attaching detaching detection unit, and where the attaching detaching detection unit detects that the external memorizing device is detached from the apparatus housing, writing the data read to the external memorizing device at the information writing unit is stopped according to an instruction from the instruction unit, and remainder of the data is read into the internal memorizing device. Thus, the internal memorizing device can store the read data instead of the external memorizing device, and where the external memorizing device is attached again to the apparatus housing, the entire data can be prevented from receiving damages by transferring the data stored in the internal memorizing apparatus to the external memorizing apparatus. According to the image processing apparatus of the invention, the apparatus can detect as to whether the prescribed responding information is in a status in processing of writing, and if the information is in the status in processing of writing, the responding information is automatically deleted. The user therefore does not need to delete the writing failed file manually, so that user's burden will be reduced. That is, even where any writing failed file is left in the external memorizing device, the user can use the external memorizing device as it is, thereby improving the efficiency of data reading work. According to the other image processing apparatus of the invention, the internal memorizing device, in lieu of the external memorizing apparatus, can store the read data and where the external memorizing device is attached again to the apparatus housing, the entire data can be prevented from receiving damages by transferring the data stored in the internal memorizing apparatus to the external memorizing apparatus. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS This invention may take physical form in certain parts and arrangements of parts, a preferred embodiment and method of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein; FIG. 1 is a block diagram showing a system structure of a multi-function peripheral according to a first embodiment of the invention; FIG. 2 is a diagram showing a USB memory and the multi-function peripheral according to a first embodiment of the invention; FIG. 3 is a flowchart of ScanToUSB memory processing done in the multi-function peripheral according to the first embodiment of the invention; FIG. 4 is a diagram showing a memory map of a USB memory used for the multi-function peripheral according to the first embodiment of the invention; FIG. 5 is a flowchart showing a deletion processing of a writing failed file in the multi-function peripheral according to the first embodiment of the invention; FIG. 6 is a screen illustration showing a display example of a display panel of the multi-function peripheral according to the first embodiment of the invention in a case where a writing failed file exists; FIG. 7 is a block diagram showing a system structure of a multi-function peripheral according to a second embodiment of the invention; FIG. 8 is a flowchart of ScanToUSB memory processing done in the multi-function peripheral according to the second embodiment of the invention; FIG. 9 is a diagram showing a storing example of image data in the multi-function peripheral according to the second embodiment of the invention; and FIG. 10 is a flowchart showing a process in the multi-function peripheral according to the second embodiment of the invention in a case where data in a USB memory are damaged and where the data are to be restored. DETAILED DESCRIPTION OF THE INVENTION First Embodiment FIG. 1 is a block diagram showing a structure of a multi-function peripheral serving as an image processing apparatus according to the first embodiment of the invention. The multi-function peripheral 100 includes a scanner unit 101 for reading original documents, an image processing unit 102 for processing image data transmitted from the scanner unit 101 or other units, a data transmission control unit 103 for controlling execution of writing, an attaching detaching detection unit 104 for detecting as to where a USB (Universal Serial Bus) memory 107 is attached to a peripheral body serving as an apparatus housing, and an accessing unit 105 having a function as a USB interface. The multi-function peripheral 100 further includes a processing identification information producing unit 201 connecting to the data transmission control unit 103 , a processing identification information retrieving unit 202 functioning as information retrieving means for retrieving writing processing information, and a control panel 203 having a display unit 204 functioning as information displaying means displaying information corresponding to the retrieved writing processing information. It is to be noted that the multi-function peripheral 100 of this embodiment include in addition to the scanner function, a facsimile transmission and reception unit 131 for performing facsimile function, and an electrophotographic printing unit 132 for printing, and as shown in FIG. 2 , the USB memory 107 serving as an external memorizing device can be detachably attached to the multi-function peripheral 100 of this embodiment. More specifically, the scanner unit 101 for reading original documents is an apparatus for reading original documents set on the multi-function peripheral's feeder such as an ADF (Automatic Document Feeder) for paper or set on a glass surface for scanning original documents, and is an apparatus for outputting an electrical signal at an image sensor in reflecting original documents' images upon radiating light out of an exposure lamp or the like to produce prescribed image data. The image processing unit 102 is a signal processing unit for converting the image data read out at the scanner unit 101 into printing data printable or data in a format storable in the USB memory 107 . The image processing unit 102 is a processing unit converting an analog signal from the scanner unit 101 into a digital signal and processing data in a prescribed way of expansion or compression, such as, e.g., edge emphasis, trimming, and page assignment with respect to the digital image signal. The data transmission control unit 103 is a controller for controlling execution of writing, stop of writing, and setting as to where to write, with respect to the image data processed in the image processing unit 102 . The data transmission control unit 103 is connected to the processing identification information producing unit 201 , and makes a processing on the processing identification information in relation to the corresponding image data. The processing identification information producing unit 201 has a function producing processing identification information when writing the image data to the USB memory 107 , and in this embodiment, the processing identification information is composed of file name 110 , storing destination information 111 , and writing processing flag 112 , as shown as an example in FIG. 4 . The file name 110 is a name where the corresponding image data are presented in a file format, and is given automatically by, e.g., CPU or made by typing input done by the user. The storing destination information 111 is the destination for storing the image data, and in this embodiment, information indicating the USB memory 107 is given to the storing destination information 111 where the USB memory 107 is attached and where the system executes the ScanToUSB memory processing as described below. The writing processing flag 112 is a flag indicating as to whether writing of the corresponding file is completed at the storing destination or not; if the data of one bit indicate “1”, it shows “writing is processing”; if the data of one bit indicate “0”, it shows “writing is not processing.” The attaching detaching unit 104 has a function detecting whether the USB memory 107 is attached to the multi-function peripheral 100 or not as well as whether the USB memory 107 is detached or not. The USB memory 107 is used as it is being inserted into a terminal without turning off the power of the multi-function peripheral 100 , or namely from a so-called “hot plug” function, and when the USB memory 107 is attached to the multi-function peripheral 100 , information corresponding to the USB memory 107 to be stored in the storing destination information in the processing identification information producing unit 201 , or namely information that the storing destination is the USB memory 107 , can be selected. The accessing unit 105 is an interface unit outputting, to the USB memory 107 , image data converted at the image processing unit 102 and retrieving the processing identification information from the USB memory 107 , and in this embodiment a USB interface is used. It is to be noted that if a memory card is used in lieu of such a USB memory, a card slot corresponding the memory card becomes the interface unit. The processing identification information retrieving unit 202 retrieves processing identification information corresponding to the image data out of a processing identification information storing unit 108 . As shown in FIG. 4 , the processing identification information corresponding to the image data is made of a combination of the file name 110 , the storing destination information 111 , and the writing processing flag 112 , and the processing identification information retrieving unit 202 checks as to whether the bit of the writing processing flag 112 is “0” or “1”, the processing identification information 202 recognizes existence of one or more writing failed files. The timing that the processing identification information retrieving unit 202 checks the status of the writing processing flag 112 is immediately after the USB memory 107 is attached to the multi-function peripheral 100 . If the writing processing flag is “1” indicating processing of writing at that time, the processing is started as the writing failed file exists. If the writing processing flag is “0” at the same timing, the processing is proceeded as having no problem. The control panel 203 is made of a display unit 204 formed of a simple display device such as, e.g., LCD (liquid crystal display), and a control unit 205 having ten keys and other buttons. The display unit 204 and the control unit 205 are formed on a surface of the housing body of the multi-function peripheral 100 . The display unit 204 functions as information displaying means for displaying information corresponding to the writing processing information. The display unit 204 and the control unit 205 can be formed of a liquid crystal touch panel, and can be used commonly with panels for controlling printing, facsimile, and photocopying functions. The control unit 205 may have an independent key entry unit. With this embodiment, the display unit 204 displays a message when the processing identification information retrieving unit 202 proceeds for processing as the writing failed file exists. FIG. 6 is a displaying example where such a writing failed file exists. A message of “writing failed file exists” is displayed at a top portion on a screen 114 of the display panel, and a word or phrase of “Delete?” is displayed to show that the system of the multi-function peripheral 100 is in a state that the system can accept an instruction of deletion. The file name “fileName01.jpg” is shown on the screen 114 of the display panel, and “folder2/meeting material/” is also displayed as a stored location, so that the user can be informed of existence of the writing failed file of the displayed file name at the displayed location. The screen 114 of the display panel displays the composing date, e.g., “2007/xx/xx 15:30”, which is a display for indicating the timing of starting production of the corresponding writing failed file recorded. A deletion button 115 indicating “delete” and a non-deletion button 116 indicating “not delete” are made to appear at a lower side of the screen 114 of the display panel, and one of the buttons can be selected. When the writing failed file is to be deleted, the deletion button 115 is selected to delete the file having the file name of “fileName01.jpg” in the USB memory 107 and its location of “folder2/meeting material/”. What is connected to the multi-function peripheral 100 thus formed is the USB memory 107 serving as an external memorizing device storing the writing processing information, and in this embodiment, the USB memory 107 includes the processing identification information storing unit 108 and an image data storing unit 109 . As shown in FIG. 2 , the USB memory 107 is detachably attached to the multi-function peripheral 100 . More specifically, a B-terminal of the USB, not shown, is formed as to face to a surface of the apparatus housing of the multi-function peripheral 100 , and when an A-terminal of the USB memory 107 is connected to the B-terminal, the USB memory 107 is connected to the multi-function peripheral 100 without turning off the power of the peripheral in a way as so-called “hot plug,” and the USB memory 107 can be disconnected without turning off the power. It is to be noted that the USB memory 107 is exemplified as the external memorizing device in this embodiment but such an external memorizing device should be interpreted with broader meaning. For example, various electronic apparatuses such as, e.g., a memory apparatus mounting an HDD (hard disc drive) to be attached externally and connectable via a USB connection, an apparatus having a memory function normally used specially for music or watching media, and a digital camera, can be used for the external memorizing device. As other external memorizing device for other embodiments of the invention, it is not limited to a memory having USB connection capability, and the memory device can be a memorizing media in a card type or chip type, such as, e.g., a memory card. With applications according to this invention, connection between the external memorizing device and the multi-function peripheral can be wired or wireless, and includes connections via network or networks using LAN connection or WAN (Wide Area Network) connection. FIG. 4 shows a memory map of the USB memory 107 ; in a memory region 113 , the processing identification information storing unit 108 and the image data storing unit 109 do storing each files. The processing identification information storing unit 108 stores data of the file name 110 , the storing destination information 111 , and the writing processing flag 112 . The USB memory 107 can be physically attached by the users at any time to the multi-function peripheral 100 , and can be detached. When the system does not allow detachment of the memory during, e.g., processing of writing, the user may inadvertently detach the USB memory in fact. A writing failed file may be left in the USB memory in case of sudden power-off due to thunder or the like. With conventional multi-function peripherals, a broken file that cannot be deleted at the peripheral is remained in case that the user inadvertently detaches the USB memory or that writing is stopped at the USB memory due to sudden power-off or the like, and therefore, it is necessary to re-insert the USB memory 107 to, e.g., a personal computer to delete the broken file. With the multi-function peripheral 100 according to the embodiment, the USB memory is not required to insert to any apparatus such as, e.g., personal computer because this apparatus works as following procedures. Referring now to FIG. 3 , a flow for executing work called as ScanToUSB memory processing in the multi-function peripheral 100 according to the embodiment is described. First, a user manipulates to start the ScanToUSB memory processing. When the ScanToUSB memory processing begins, the processing identification information is produced with the processing identification information producing unit 201 at step S 100 . This processing identification information is for providing identification information in the system for scanning operation, which is conducted subsequently. The processing identification information is made of the combination of the file name 110 , the storing destination information 111 , and the writing processing flag 112 as shown in FIG. 4 . The processing identification information can includes, in addition to above, information such as, e.g., time of production and renewal with respect to files, and in this regard, the processing identification information is the same as normal image data files. The processing identification information produced at the processing identification information producing unit 201 is transmitted to the data transmission control unit 103 and is temporally stored at the unit 103 . The writing processing flag 112 among data of the processing identification information is produced as to be “1” indicating “processing of writing” because writing operation is to start with respect to the USB memory 107 . Subsequently, original documents set on the scanner unit 101 are read (step S 101 ). In this step, a signal corresponding to the set original documents generated with an image sensor equipped at the scanner unit 101 is sent to the image producing unit 102 . Image processing is then executed at step S 102 to convert the signal about the read image into data in a storable format that the user wants. At that time, data, as image file formats, can be converted into some file formats widely used for personal computers such as, e.g., bitmap, JPEG, GIF, PDF. Data are also not limited to those and can be converted to original formats. Users may give information such as, e.g., file size, color information, enlargement or reduction in size, page, grayscale, but with this multi-function peripheral, the USB memory 107 may include those data of the image processing information, and those can be read to be used for processing. At step S 103 , the data are transmitted. This data transmission is for transmitting image data toward the USB memory 107 in accompany with the processing identification information that have been produced at the processing identification information producing unit 201 . Normally, a specific transmission size is predetermined where image data are transmitted to a memory device, and therefore, image data are sent by each in the predetermined size, so that the transmissions are repeated by each in the predetermined size as a loop up to the completion of transmission of the entire image data. At that time, the processing identification information produced at the processing identification information producing unit 201 can be sent as a firstly sent data likewise a header in a signal format. A memory functioning as a buffer can be temporarily used for the transmission destination. At step S 104 , it is confirmed that the USB memory 107 is recognized using a signal from the attaching detaching detection unit 104 . Where the recognition of the USB memory 107 is confirmed (yes), or in other words, where the USB memory 107 is physically as well as electrically connected to the multi-function peripheral 100 , writing is made to the recognized USB memory 107 (step S 105 ). The processing identification information that have been produced at the processing identification information producing unit 201 is transmitted to the processing identification information storing unit 108 at an initial stage of writing to the USB memory 107 , and the USB memory 107 stores “1” indicating processing of writing as a stored value of the writing processing flag 112 among data of the processing identification information. The writing processing of the image data done in the USB memory 107 is executed according to the loop step S 107 because this writing processing becomes repetitive processing work. Where the loop step S 107 finishes, the transmission of the entire image data to the image data storing unit 109 is completed, thereby ending the writing processing. Subsequently, the stored value of the writing processing flag 112 among the data of the processing identification information in the USB memory 107 is switched from “1” to “0”. As described above, where the stored value of the writing processing flag 112 is “0”, the data indicate a status of not processing of writing, and this switching operation shows that the writing is completed properly. Such renewal of the processing identification information in the USB memory 107 can be made by data transmission sent again from the processing identification information producing unit 201 or by inclusion of a signal for automatic renewal at the end of the image data to be sent. Although the flow at steps S 105 , S 107 , and S 108 shows a streamline in a case where writing to USB memory 107 ends in an ordinary manner. If a user pulls out the USB memory 107 , this causes canceling during execution of processing as shown at step S 106 . In such a case, the attaching detaching detection unit 104 recognizes that the USB memory 107 is pulled out, and the system stops this ScanToUSB memory processing. A writing failed file is left on a side of the USB memory 107 at that time, but in the multi-function peripheral 100 according to the embodiment, the existence of the writing failed file is recognized at a time when the USB memory 107 is attached again to the apparatus housing, and is displayed. Upon choosing the button for deletion, the writing failed file can be deleted. Referring to FIG. 5 , a deletion processing of a writing failed file in the embodiment is described. The deletion processing of the writing failed file is normally a processing executed immediately after the USB memory 107 is connected to the multi-function peripheral 100 . If any writing failed file is left in the USB memory 107 , the memory region is used in a wasting manner for that portion, and in some cases, an adequate memory region cannot be obtained. Upon executing the deletion processing of the writing failed file, the region used uselessly can be extinguished. As shown in FIG. 5 , a judgment is first made as to whether the USB memory 107 is connected to the multi-function peripheral 100 , and step S 200 shows a procedure in which the USB memory 107 is recognized as connected to the multi-function peripheral 100 . Where the USB memory 107 is not connected, the USB memory 107 is not recognized, and the respective steps in the flow shown in FIG. 5 do not occur. The processing identification information retrieving unit 202 serving as information retrieving means for retrieving writing processing information, operates to retrieve the stored value in the writing processing flag 112 of the processing identification information storing unit 108 in the USB memory 107 , and it is judged as to whether the stored value of the writing processing flag is “1” or not (step S 201 ). The stored value of the writing processing flag 112 in the processing identification information storing unit 108 is either “1” indicating processing of writing or “0” indicating not processing of writing. If the writing processing flag 112 is “1” indicating processing of writing (yes), the processing goes on as a writing failed file exists. If the writing processing flag 112 is “0” indicating not processing of writing (no), the processing is made to end. Where the writing processing flag 112 is “1” indicating processing of writing (yes), the screen is made to show a message indicating this (step S 202 ). That is, displaying operation is made as shown in FIG. 6 as described above, and a prescribed display is made at the display unit 204 of the control panel 203 according to the signal from the processing identification information retrieving unit 202 . More specifically, the screen 114 of the display panel displays a message “writing failed file exists” at an upper portion as shown in FIG. 6 , and displays a message “Do you delete it?”, so that the system of the multi-function peripheral 100 is shown as in a state receivable of an instruction of deletion. The screen 114 of the display panel also shows “fileName01.jpg” as the file name and “folder2/meeting material/” as the shoring location, and the system shows that a writing failed file having the displayed file name at the displayed location exists. The screen 114 of the display panel yet further shows the producing date of “2007/xx/xx 15:30”, which displays the timing of the recorded production start of the writing failed file. The deletion button 115 indicating “delete” and the non-deletion button 116 indicating “not delete” are made to appear at the lower side of the screen 114 of the displaying panel, and the user can choose either buttons. It is to be noted that the displayed example shown in FIG. 6 is not more than one example, and can be other display types. For example, the screen can be of a display type having light emitting diodes indicating existence of the writing failed file by the diodes' turning on, or the system can be structured to inform of the existence of the writing failed file to user's address by email or the like. Step S 203 is a step at which either one of the deletion button 115 indicating “delete” and the non-deletion button 116 indicating “not delete” is entered, and if the user selects the button of “not delete” (no), the writing failed file is not deleted, the program step goes to step S 205 . If the user chooses the deletion button 115 indicating “delete”, the program step goes to step S 204 . The writing failed file corresponding to the file name “filename01.jpg” in the example shown in FIG. 6 , which is displayed on the screen 114 of the display panel, is then deleted. The program step goes to step S 205 after this deletion of the writing failed file. The writing processing flag 112 of the processing identification information is renewed from the value “1” indicating processing of writing to the value “0” indicating not processing of writing. With this status change of the flag, no writing failed file exists to be deleted for the user in the USB memory 107 . According to the flow shown in FIG. 5 , with the multi-function peripheral 100 , the deletion processing of the writing failed file is executed immediately after the USB memory 107 is connected to the multi-function peripheral 100 . It is therefore unnecessary for the user to manipulate deletion by inserting the USB memory to a personal computer to delete the writing failed file, so that the useless file can be deleted surely in a short time. For example, where plural multi-function peripherals 110 are installed in the same area, it is not necessary to render the multi-function peripheral 100 creating a result of failed writing identical to the multi-function peripheral 100 performing deletion of the writing failed file for recovery work, and any other multi-function peripherals can perform such deletion. It is to be noted that although the processing identification information is written into the USB memory after the original document is read in the ScanToUSB memory processing as described above, the original document can be read after processing identification information including writing processing flag data having the value “1” meaning processing of writing is first written in the USB memory. Second Embodiment FIG. 7 is a block diagram showing a structure of the multi-function peripheral 200 serving as an image processing apparatus according to the second embodiment of the invention. The same reference numbers are assigned to respective members of the multi-function peripheral 200 in this embodiment, which are substantially the same to the respective member of the multi-function peripheral 100 in the first embodiment. The multi-function peripheral 200 includes a scanner unit 101 for reading original documents, an image processing unit 102 for processing image data transmitted from the scanner unit 101 or other units, a data transmission control unit 103 for controlling execution of writing, an attaching detaching detection unit 104 for detecting as to where a USB (Universal Serial Bus) memory 107 is attached to a peripheral body serving as an apparatus housing, an accessing unit 105 having a function as a USB interface, and an internal HDD 106 (Hard Disc Drive) serving as an internal memorizing device connected to the data transmission control unit 103 . It is to be noted that the multi-function peripheral 200 of this embodiment includes in addition to the scanner function, a facsimile transmission and reception unit 131 for performing facsimile function, and an electrophotographic printing unit 132 for printing, and in substantially the same manner as the multi-function peripheral 100 in the first embodiment as shown in FIG. 2 , the USB memory 107 serving as an external memorizing device can be detachably attached to the multi-function peripheral 200 of this embodiment. More specifically, the scanner unit 101 for reading original documents is an apparatus for reading original documents set on the multi-function peripheral's feeder such as an ADF (Automatic Document Feeder) for paper or set on a glass surface for scanning original documents, and is an apparatus for outputting an electrical signal at an image sensor in reflecting original documents' images upon radiating light out of an exposure lamp or the like to produce prescribed image data. The image processing unit 102 is a signal processing unit for converting the image data read out at the scanner unit 101 into printing data printable or data in a format storable in the USB memory 107 . The image processing unit 102 is a processing unit converting an analog signal from the scanner unit 101 into a digital signal and processing data in a prescribed way of expansion or compression, such as, e.g., edge emphasis, trimming, and page assignment with respect to the digital image signal. The data transmission control unit 103 functions as a controller for controlling execution of writing, stop of writing, and setting as to where to write, with respect to the image data processed in the image processing unit 102 . The data transmission control unit 103 is connected to the internal HDD 106 (Hard Disc Drive) serving as an internal memorizing device, and has a structure capable of transmitting data to the HDD 106 . The attaching detaching unit 104 has a function detecting whether the USB memory 107 is attached to the multi-function peripheral 100 or not as well as whether the USB memory 107 is detached or not. The USB memory 107 is used as it is being inserted into a terminal without turning off the power of the multi-function peripheral 200 , or namely from a so-called “hot plug” function, and when the USB memory 107 is attached to the multi-function peripheral 200 , the attachment is detected to make the USB memory as one of selectable destination of the data. The accessing unit 105 is an interface unit outputting, to the USB memory 107 , image data converted at the image processing unit 102 and retrieving the necessary information from the USB memory 107 , and in this embodiment a USB interface is used. It is to be noted that if a memory card is used in lieu of such a USB memory, a card slot corresponding the memory card becomes the interface unit. The data transmission control unit 103 is further connected to the processing identification information producing unit 201 , and makes a processing on the processing identification information in relation to the corresponding image data. The processing identification information producing unit 201 has a function producing processing identification information when writing the image data to the USB memory 107 , and in this embodiment, the processing identification information is composed of file name, storing destination information, and writing processing flag. The file name is a name where the corresponding image data are presented in a file format, and is given automatically by, e.g., CPU or made by typing input done by the user. The storing destination information is the destination for storing the image data, and in this embodiment, information indicating the USB memory 107 is given to the storing destination information 111 where the USB memory 107 is attached and where the system executes the ScanToUSB memory processing as described below. The writing processing flag is a flag indicating as to whether writing of the corresponding file is completed at the storing destination or not; if the data of one bit indicate “1”, it shows “writing is processing”; if the data of one bit indicate “0”, it shows “writing is not processing.” With this embodiment, the image data are stored upon assignments of page numbers corresponding to the respective pages. The assignments of the corresponding page numbers are made in a manner to sequentially assign each page number to prescribed data with the data transmission control unit 103 . The multi-function peripheral 200 of this embodiment can manage against damaged data in the pages as described below by this method for storing image data. What is connected to the multi-function peripheral 200 thus formed is the USB memory 107 serving as an external memorizing device storing the writing processing information, and in this embodiment, the USB memory 107 includes the processing identification information storing unit 108 and an image data storing unit 109 in substantially the same manner as in the first embodiment. The USB memory 107 is detachably attached to the multi-function peripheral 200 . More specifically, a B-terminal of the USB, not shown, is formed as to face to a surface of the apparatus housing of the multi-function peripheral 100 , and when an A-terminal of the USB memory 107 is connected to the B-terminal, the USB memory 107 is connected to the multi-function peripheral 100 without turning off the power of the peripheral in a way as so-called “hot plug,” and the USB memory 107 can be disconnected without turning off the power. Although the USB memory 107 is exemplified as the external memorizing device in this embodiment, other memory cards or electronic apparatuses can be used, and connection between the external memorizing device and the multi-function peripheral can be wired or wireless and includes connections via network or networks using LAN connection or WAN (Wide Area Network) connection, as in substantially the same manner as those in the first embodiment. The USB memory 107 , in substantially the same manner as in the first embodiment, can be physically attached by the users at any time to the multi-function peripheral 200 , and can be detached. When the system does not allow detachment of the memory during, e.g., processing of writing, the user may inadvertently detach the USB memory in fact. A writing failed file may be left in the USB memory in case of sudden power-off due to thunder or the like. With conventional multi-function peripherals, a broken file that cannot be deleted at the peripheral is remained in case that the user inadvertently detaches the USB memory or that writing is stopped at the USB memory due to sudden power-off or the like, and therefore, it is necessary to re-insert the USB memory 107 to, e.g., a personal computer to delete the broken file. With the multi-function peripheral 200 according to the embodiment, the USB memory is not required to insert to any apparatus such as, e.g., personal computer because this apparatus works as following procedures. Moreover, with the multi-function peripheral 200 , in a case where a file is damaged in a midway of a page, the data are stored from the incident page by the substituted HDD 106 serving as the internal memorizing device, and at a time that the USB memory 107 is under recovery, the system performs an effective recovery from the data damaged at the midway of the page by transmitting the data out of the HDD 106 . Referring now to FIG. 8 , a flow for executing work called as ScanToUSB memory processing in the multi-function peripheral 200 according to the embodiment is described. First, a user manipulates to start the ScanToUSB memory processing. When the ScanToUSB memory processing begins, the original documents set to the scanner unit 101 are read at step S 300 . In this step, a signal corresponding to the set original documents generated with an image sensor equipped at the scanner unit 101 is sent to the image producing unit 102 . The processing identification information made of the combination of the file name, the storing destination information, and the writing processing flag is produced with the processing identification information producing unit 201 at that step. The writing processing flag among data of the processing identification information is particularly produced as to be “1” indicating “processing of writing” because writing operation is to start with respect to the USB memory 107 . Image processing is then executed at step S 301 to convert the signal about the read image into data in a storable format that the user wants. At that time, data, as image file formats, can be converted into some file formats widely used for personal computers, and data are also not limited to those and can be converted to original formats. Users may give information such as, e.g., file size, color information, enlargement or reduction in size, page, grayscale, but with this multi-function peripheral, the USB memory 107 may include those data of the image processing information, and those can be read to be used for processing. At step S 302 , the data are transmitted. This data transmission is for transmitting image data toward the USB memory 107 in accompany with the processing identification information that have been produced at the processing identification information producing unit 201 . Normally, a specific transmission size is predetermined where image data are transmitted to a memory device, and therefore, image data are sent by each in the predetermined size, so that the transmissions are repeated by each in the predetermined size as a loop up to the completion of transmission of the entire image data. At that time, the processing identification information produced at the processing identification information producing unit 201 can be sent as a firstly sent data likewise a header in a signal format. In this embodiment, the page number corresponding to the pages of the image data are added as additional information at the transmission of the image data, and are added to, e.g., the header portion of each page. Where the page numbers are already added on the data format at the transmission of the image data, it is unnecessary to add further any page number, and the information on the page number in the data format can be used as it is. At step S 303 , it is confirmed that the USB memory 107 is recognized using a signal from the attaching detaching detection unit 104 . Where the recognition of the USB memory 107 is confirmed (yes), or in other words, where the USB memory 107 is physically as well as electrically connected to the multi-function peripheral 200 , writing is made to the recognized USB memory 107 (step S 304 ). The processing identification information that have been produced at the processing identification information producing unit 201 is transmitted to the processing identification information storing unit 108 at an initial stage of writing to the USB memory 107 , and the USB memory 107 stores “1” indicating processing of writing as a stored value of the writing processing flag. Hereinafter, the same operation is executed in a loop processing (S 306 ), and writing into the USB memory 107 is made to go on as always confirming the USB memory 107 . Even if the existence of the USB memory 107 is confirmed at first during the ScanToUSB memory processing, the USB memory 107 may be pulled out in a midway, and in such a case, the system makes processing as the condition at step S 303 becomes “No” at that time. It is confirmed as to whether the USB memory 107 is recognized using the signal from the attaching detaching detection unit 104 . If communications with the USB memory 107 are cut off due to a reason such that the USB memory 107 is physically pulled out of the multi-function peripheral 200 , recognition on the USB memory 107 cannot be confirmed (No). In such as case, the program step goes to step S 305 , and the data are written into the HDD 106 serving as the internal memory device. Hereinafter, the same operation is executed with the loop processing (S 306 ), and thereby, the data are further written into the HDD 106 . Writing the image data into the HDD 106 corresponds to information on the page numbers as descried above, and this writing operation is described with reference to FIG. 9 . FIG. 9 is a diagram showing a storing example of the image data. If the scanner unit 101 reads an original document to obtain data of first to fifth pages as the image data, the image data are sequentially transmitted in accordance with page number information where the data are written into the USB memory 107 . As writing into the USB memory goes on, if the user pulls the USB memory 107 out of the multi-function peripheral 200 at a time that the image data corresponding to, e.g., the fourth page are transmitted, the image data corresponding timely to the fourth page become damaged data. At that time, the data from the first to third pages are left in the USB memory 107 as data successfully written. When the user pulls the USB memory 107 out of the multi-function peripheral 200 , the program step goes to the processing of S 305 in the previous processing, and the HDD 106 , as the internal memory device, begins storing the data in lieu of the external memory device. The HDD 106 begins storing from the fourth page image data corresponding to the damaged data, and particularly stores the fourth page and the fifth page in a way to record again from the starting portion of the fourth page image data. If the user thus pulls the USB memory 107 inadvertently out of the multi-function peripheral 200 in a midway of the data transmission, the HDD 106 stores the data from the data corresponding to the page. FIG. 10 is a flow in a case where the data recovery is made after the user pulls the USB memory 107 out of the multi-function peripheral 200 in a midway of the data transmission. Referring to the flow shown in FIG. 10 , the example ( FIG. 9 ) in which the fourth page is damaged is described. As shown in FIG. 10 , a judgment is first made as to whether the USB memory 107 is connected to the multi-function peripheral 200 , and step S 400 shows a procedure in which the USB memory 107 is recognized as connected to the multi-function peripheral 200 . Where the USB memory 107 is not connected, the USB memory 107 is not recognized, and the respective steps in the flow shown in FIG. 10 do not occur. The processing identification information retrieving unit serving as information retrieving means, not shown, operates to retrieve the stored value in the writing processing flag of the processing identification information storing unit 108 in the USB memory 107 , and it is judged as to whether the stored value of the writing processing flag is “1” or not (step S 401 ). The stored value of the writing processing flag in the processing identification information storing unit 108 is either “1” indicating processing of writing or “0” indicating not processing of writing. If the writing processing flag is “1” indicating processing of writing (yes), the processing goes on as a writing failed file exists. If the writing processing flag 112 is “0” indicating not processing of writing (no), the processing is made to end. If the writing processing flag is “1” indicating processing of writing (yes), re-writing is executed at step S 402 . In this re-writing processing, though data are transmitted from the HDD 106 to the USB memory 107 , data are transmitted in a way to overwrite the damage fourth page image data, and the first to fifth page of the original image data come to be stored at the end of the data transmission. At the end of the data transmission, the storing value of the writing processing flag of the processing identification information storing unit 108 is renewed to “0”, and it shows a status that no writing failed file exists. Subsequently, the fourth page and the fifth page used for overwriting in the USB memory 107 are deleted among the data stored in the HDD 106 serving as the internal memorizing device. The recognition processing on the USB memory is completed by deletion of the data shored in the HDD 106 . As described above, with the multi-function peripheral 200 according to this embodiment, the HDD 106 operable in a substituted fashion stores data dropped out of the USB memory even where some writing failed file is produced in the USB memory due to the USB memory's inadvertently pulling out, the writing failed file can be deleted by overwriting from the damaged page when the USB memory 107 is inserted again. Therefore, it is unnecessary for users to manipulate the deletion operation upon inserting the USB memory to their personal computer to delete the writing failed file, so that useless files can be deleted surely in a short time. It is to be noted that although in this embodiment it is describe that the image data can be overwritten by a page basis, the apparatus can adapt a system doing re-writing by other image unit basis. The multi-function peripheral 200 according to the second embodiment can be formed with a prescribed display unit, and damaged pages among the image data can be shown. In the embodiments described above, the apparatuses having the scanner function, facsimile function, photocopier function, and printer function are described, but any apparatus can be used for the embodiments as far as the apparatus having a scanner function, and it is not necessary for the multi-function peripheral to have respective functions other than the scanner function. Display of the writing failure at the display unit is not necessarily in texts and can be in forms of icons or illustrations. With the multi-function peripherals according to the embodiments, the peripherals may have plural USB terminals; the internal memorizing device can be a part of an HDD used for photocopier other than the HDD described above; the internal memorizing device itself can be such as, e.g., a memory card, an extended memory, and a memorizing medium in a disc shape; the internal memorizing device can be formed of a server connected through LAN or WAN or formed inside other personal computer. The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The description was selected to best explain the principles of the invention and their practical application to enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention should not be limited by the specification, but be defined by the claims set forth below.	An image processing apparatus has an internal memory section installed within an apparatus housing, a communication section for performing data communications with an external memory medium detachably attached to the apparatus housing, and a data writing section for writing data to the external memory medium. When the data writing section detects that the external memory medium is detached from the apparatus housing during writing the data to the external memory medium, the data writing section writes target data that is in a process of writing to the external memory medium to the internal memory section. When the data writing section detects that the external memory medium is attached again to the apparatus housing, the data writing section reads out the target data from the internal memory section, and writes the target data to the external memory medium.	6
CROSS REFERENCE TO RELATED APPLICATIONS [0001] This U.S. patent application claims the benefit of PCT patent application No. PCT/EP2015/065448, filed Jul. 7, 2015, which claims the benefit of German patent applications No. 10 2014 213 153.7, filed Jul. 7, 2014, and 10 2014 219 334.6 filed Sep. 24, 2014 all of which are hereby incorporated by reference. TECHNICAL FIELD [0002] The invention relates to a guiding system for a brake piston of a motor vehicle disk brake. BACKGROUND [0003] In the known motor vehicle brakes, there is a systematic separation of functions in that forces are mechanically braced and the brake piston guided linearly in the housing by direct bearing contact on the basis of a defined finish-machined cylindrical fit of the paired component diameters, that it to say between the cylindrical brake piston wall and the cylindrical brake piston bore wall. An elastic sealing ring is accommodated in the housing on the plunger principle and seated centrally with radially inward resilience on the brake piston wall, in order to fulfil a hydraulic sealing function, and a so-called roll-back function following brake actuation. In the case of fixed-caliper brakes only a brake piston is pushed back by the roll-back function. In the case of floating-caliper brakes this return relates both to the brake piston and also to the housing. [0004] Page 98 of the 3 rd edition (2006) of the Brake Manual-ISBN-10 3-8348-0064-3 schematically describes the basic working principle of a conventional floating-caliper brake and page 95 the mode of operation of a conventional sealing ring for use in motor vehicle disk brakes. Following release of an actuated brake, the brake piston is in the unpressurized state due to elastic recovery of the sealing ring, the wall thereof gripping adhesively on the brake piston wall, automatically drawn back (roll-back behavior). The recovering sealing ring consequently impresses said return effect on the brake piston and the housing. [0005] DE 16 00 008 A1 discloses a method of influencing said automatic return behavior by reducing the coefficient of friction between the brake piston bore and the brake piston wall. To do this it is proposed to make the brake piston wall from carbon or graphite so that it is self-lubricating. This calls for exacting special processes, it is susceptible to wear and unfortunately the brake piston, in terms of its thermal and mechanical characteristics, does not function satisfactorily in all applications. [0006] DE 38 00 679 A1 sets forth a sealing device, wherein one surface is roughened in order to reduce a stick-slip effect. Investigations have shown that by using a surface formed with such a microstructure (as opposed to an entirely smooth surface) it is possible to maintain a fine fluid wetting between the brake piston and the sealing ring, so that stick-slip is avoided. Since the sealing ring, due to fluid wetting and a low coefficient of friction, finds little adhesion or resistance for transmitting force to the brake piston, the roll-back behavior is also less pronounced. This may have a detrimental effect in the case of floating-caliper brakes. [0007] DE 103 53 827 A1 provides for a sealing ring having at least one orbitally and annularly grooved sliding surface for bearing against a brake piston wall. Here the grooving runs transversely at right angles to a brake piston axis. [0008] In order to improve the efficiency, DE 197 49 612 C2 discloses a fixed-caliper brake having a brake piston-cylinder unit and a wobble joint for the brake piston. For forming the wobble joint the brake piston accommodates an elastic seal. The brake piston is accommodated centrally in a piston bore and is flexibly and displaceably supported by the seal. Under pressure in operation of the brake, this allows a brake piston axis to be oriented at right angles to a rear side of a brake pad. Here the orientation inevitably varies as a function of an elastic housing deformation under an increasing brake pressure. The brake piston is clamped symmetrically in the radial direction by the seal (symmetrical clamping). [0009] A more recent analysis designed to model the noise-vibration-harshness (NVH) in disk brakes largely focuses on preventing reduced comfort due to high-frequency noise. One finding of this research is that with current disk brake specifications and requirements subsequent detailed enhancements are generally no longer sufficient to achieve a lasting improvement. An object of the present invention, therefore, is to afford an overall improvement, that is to say a basic systematic improvement of the NVH and roll-back characteristics of the oscillating system in all operating states, that is also in an unpressurized state, without bringing hitherto beneficial effects into question. [0010] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. SUMMARY [0011] The brake piston guide is considered as a sub-system of a motor vehicle brake system relevant to the modal acoustics that in a particular form can be “pitched and tuned”. Through a particular combination of the boundary conditions between the brake piston bore and the brake piston wall the guide means is clamped, reversibly elastically “tuned”, in such a way that the guide means is supported on the brake caliper housing, and permanently acts upon the brake piston with a defined action of lateral force, affording the brake piston wall a measured controlled, modal-acoustic coupling to the bore wall, as required. The guide means therefore produces a modally acoustic “eccentric” tuning inside the piston accommodation between the brake piston wall and the bore. The guide means/sealing ring accordingly for the first time has a dual function, in such a way that it performs and exercises not only the known sealing function but also at the same time a lateral force modulation function (in relation to the brake piston). A purely radially symmetrical seal clamping of a brake piston is refrained from by impressing a defined lateral force, asymmetrically modulated at the circumference, on the brake piston, which gives the piston a defined preferred orientation in a lateral direction and/or a defined setting angle. Accordingly, hysteresis errors in the brake piston return behavior, brake piston sticking, unwanted torsion of the brake piston, residual braking moments, discernible instability in brake pedal actuation and unwanted oscillation noises are prevented by the new type of accommodation due to the particular clamping and modal acoustic decoupling of the brake piston. The system is also standardized and simplified, because its guide function is performed substantially by standardized identical parts. [0012] In one particular development it is possible to decouple a brake piston, as required, in all operating states through specific, asymmetrical elastic clamping. The piston is therefore given a specific orientation, axial offset and/or a defined setting angle α, wherein the brake piston axis may be arranged axially offset and/or inclined in relation to the piston bore even in the unpressurized state. Particularly with a specifically decentralized, that is to say asymmetrically and elastically laterally braced piston accommodation in the housing, it is possible by relatively simple means to impress varying preferred orientations on a piston in a lateral direction and/or if necessary to arrange the brake piston axis at an oblique angle in the housing. This in turn has the positive consequence that unwanted reductions in comfort can be prevented by means of acoustic tuning. All of this is done very cost-effectively in the case of piston bores conventionally machined at right angles in the housing, and moreover in the actuated as well as the unactuated operating state. Since quite differently acting and primarily mechanically manifest alternative solutions for the lateral force modulation have been identified the characteristics for each of these may be designated singly or associated with one another in any combination, without departing from the scope of the invention. [0013] Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0014] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: [0015] FIG. 1 schematically illustrates a floating-caliper brake; [0016] FIG. 2 shows an enlarged view of a portion of a brake piston bore including accommodation for a guide means in a housing; [0017] FIGS. 3 to 5 show different views of a first embodiment of a guide means; [0018] FIGS. 6 and 7 show different views of a second embodiment of a guide means; [0019] FIG. 8 shows a detail of the guide means according to FIGS. 6 and 7 in an installed situation in a housing;, [0020] FIGS. 9 and 10 show different views of a third embodiment of a guide means; [0021] FIG. 11 illustrates details of the guide means according to FIGS. 9 and 10 in an installed situation in a brake piston bore of a housing; [0022] FIG. 12 shows a qualitative comparison of the action of forces F of the piston clamping in relation to the piston displacement s, using the different configurations, that is according to a) conventional, rigid piston guide system, b) additionally decoupled, centrally pre-stressing guide element, c) eccentrically pre-stressing, eccentric guide element, and d) axially offset groove between guide element and/or seal; [0023] FIG. 13 shows an embodiment of the invention having an axially offset groove and a special groove profile; and [0024] FIG. 14 shows a dual piston application of the embodiment according to FIG. 13. DETAILED DESCRIPTION [0025] Each hydraulic actuator such as, in particular, a motor vehicle disk brake 1 comprises at least one guiding system 2 for at least one translationally displaceable brake piston 3, which is accommodated in a housing 4, such as, in particular, in a brake caliper or cylinder. Here the guiding system 2 may relate equally both to the guiding systems of the brake pistons of input actuators (that is hydraulic brake master cylinders, for example) or to the guiding systems for brake pistons of output actuators (such as motor vehicle hydraulic disk brakes, for example). [0026] Brake master cylinders generally comprise two brake pistons (primary and secondary piston), hydraulically connected independently of one another and accommodated so that they are translationally displaceable in a bore, which pistons as a displaceable wall define pressure chambers, which are connected to pressure chambers of associated motor vehicle disk brakes, which are in turn defined by brake pistons. In a motor vehicle disk brake 1 of the floating-caliper type at least one brake piston 3 defines a pressure chamber 5, which is actuated by a hydraulic upstream input actuator. Motor vehicle disk brakes 1 of the fixed-caliper type, however, comprise at least one brake piston 3 on each side of a brake disk 6. [0027] When actuated by a master cylinder, incompressible brake fluid in each volumetrically closed hydraulic system (master cylinder, pipelines, brake hose lines, motor vehicle disk brake 1, brake piston 3) is subjected to hydraulic pressure in accordance with the law of volume constancy, in such a way that at least one friction lining 7, 8 is directly or indirectly pressed against a rotor (brake disk 6) by the brake piston 3 after overcoming a so-called free travel. A surface unit pressure (cf. brake pressure), which correlates with a specific brake application force, serves as a measure of this braking action. For releasing the motor vehicle disk brake 1 the master cylinder is released, unactuated. The sealing ring 9 is accommodated in a recess/groove 10. The elasticity and elastic roll-back effect of the sealing ring 9 is exploited for returning the brake piston 3. Consequently, the desired clearance after braking is produced substantially by a reversible return deformation of the sealing ring 9. [0028] A brake piston 3 is basically of cup-shaped construction and comprises a brake piston head 11 and a cylindrical brake piston wall 12. According to the type of disk brake, either the brake piston head 11 or an exposed edge of the brake piston wall 12 may act directly on the friction lining 7, 8. [0029] The guiding system 2 for a brake piston 3 of a motor vehicle disk brake 1, or other actuators, comprises a brake piston bore 13 arranged concentrically with and cylindrically around the brake piston 3 for the axially displaceable accommodation of the brake piston 3 in the housing 4 (in particular a brake caliper housing), and a sealing ring 9 which is supported in the brake caliper housing and is elastically clamped between the cylindrical brake piston wall 12 and the recess 10 of the brake piston bore 13, and which serves the functions described above. [0030] A guide means 15 is provided in a reversibly elastically clamped manner in a gap 14 between the brake piston bore 13 and the brake piston wall 12, which guide means is supported on the brake caliper housing and permanently clamps the brake piston 3 with a defined action of forces in a radial direction in such a way that the brake piston wall 12 is coupled, with a specific orientation, to the brake piston bore wall. This accordingly results in an oriented accommodation of the brake piston 3 in the housing 4. A guide means 15 clamping with a defined elastic pliability affords an improved introduction of lateral forces into the housing 4. [0031] The guide means 15 is to be integrally formed with the sealing ring 9 and arranged in a common recess of the brake piston bore 13, so as to reduce the assembly and machining outlay. If the machining and assembly outlay are of lesser concern, and a facility for separate replacement is desired, the guide means 15 and the sealing ring 9 may be formed and accommodated side-by-side as separate components. For this purpose, the guide means 15 and the sealing ring 9 are located at an axial interval from one another, each in separate recesses 10, 16 of the brake piston bore 13. The recesses 10, 16 may comprise fixing means such as, in particular, parallel bearing faces 17, 18 for the sealing ring 9 and the guide means 15. In principle, there is scope for providing the guide means 15 with a uniform clamping force over the circumference of the brake piston. In service this automatically results in the provision of a brake piston axis A substantially at right angles to the friction surfaces of the brake disk 6. [0032] In an alternative configuration, wherein a sealed gap 14 runs between the brake piston bore 13 and the brake piston wall 12, and the brake piston axis A is not set at right angles to the friction surface of the brake disk 6 but at a defined oblique angle. This is achieved in one embodiment in that a radial action of force of a clamping of the brake piston wall 12 is not provided uniformly over the brake piston circumference, and the lateral forces do not cancel one another out. What is more, as a result a defined lateral force with a corresponding resultant preferred orientation is impressed on the brake piston 3, wherein the setting angle obtained corresponds to the direction of the resultant lateral force. The action of the forces, in this way non-uniformly distributed over the brake piston circumference, for producing a setting angle can be obtained through corresponding adaptation of the elasticity of a material of the guide means 15. [0033] Accordingly, according to FIGS. 3-5 a cross section of the guide means 15 is specifically designed to be pliably elastic in a preferred displacement area, for example through raised ribs 19 protruding convexly outwards, lobes or similar projections and at least one correspondingly associated integral cavity 20. The cavity 20 affords the necessary elastic freedom of movement. Moreover, a radial lateral force is impressed on the brake piston 3, where necessary lending it a predefined, desired setting angle α. The individual ribs 19 or lobes preferably extend more lengthwise than widthwise and running uniformly in an axial direction, that is to say oriented parallel to the brake piston axis A. The height of the ribs 19 in this context defines the radial clamping of the brake piston 3 in accordance with the outside diameter of the brake piston wall 12 and the inside diameter of the brake piston bore 13. [0034] In a simple variant according to FIGS. 6-8 a separate guide means 15 may be formed as a simple corrugated ring from a solid material (for example spring steel) of uniform wall thickness, the cross section of which is meander-shaped and has alternating convex and concave portions. A correspondingly adapted coaxial-cylindrical brake piston wall and a coaxial-cylindrical brake piston bore 13 are assigned to this. Alternatively or in addition to this another variant suggests itself, in which the guide means is formed as a bow spring having at least one sprung arm. [0035] As a further alternative or addition, it is feasible to provide the respective groove seats for the sealing ring and/or guide means axially offset in the housing—that is to say with an axial offset Δ in relation to the piston bore. As a further alternative or addition, it is feasible to form the sealing ring and/or the guide means eccentrically. As a further alternative or addition, it is possible to provide the sealing ring 9 and/or the guide means 15 formed from a material of different elasticity. It is possible for the elastic guide means 15 to comprise at least one component formed at least partially from a metal material, such as, in particular, spring steel. It is in particular possible to provide different, alternating moduli of elasticity in relation to the azimuth angle (Az). This is possible, for example, by virtue of the aforementioned material composite structure and/or another elastomer multi-material construction. [0036] Alternatively or in addition, the orbital elastic pressure modulation at the circumference, in particular directed radially at the brake piston 3, may be obtained in that a recess 10, 16 for accommodating the sealing ring 9 and/or guide means 15 is provided with a profiled base surface 40 by providing at least one or more irregularities on the circumference of the base surface 40. The irregularity may be formed as a sectoral flattening, protuberance, recess or other deformation of the base surface 40, allowing a correspondingly modified accommodation and action of the sealing ring 9 and/or guide means 15 to achieve correspondingly modified, modulated spring effects, which orbitally at the circumference produce the desired pressure modulation, basically directed radially at the piston 3. Accordingly, the irregularity/irregularities is/are preferably provided radially oriented in the base surface 40 and may preferably be designed as variations in radius, so that the base surface runs as a closed, non-circular, elliptical, ovoidal or other freeform curve around the brake piston 3. Said pressure modulation therefore makes it possible to achieve the spot and/or linear contact at the * point between brake piston wall 12 and brake piston bore wall represented in principle and by way of example in FIG. 12 A-D—where necessary maintaining the setting angle α described (angle between the brake piston axis A and the bore axis in the housing 4). [0037] The annular guide means 15 according to the invention is furthermore preferably formed entirely or at least partially from a plastic material, such as in particular PTFE or a PTFE constituent. The guide means is more preferably of annular design, wherein at least one ventilation duct 21—as it were, as a bypass—is provided for the purpose of pressure equalization and for the return flow of fluid (brake fluid) into the pressure chamber 5. Each ventilation duct 21 may be designed as an aperture 22 provided radially or obliquely on the annular guide means 15. It is possible for the guide means 15 to have additional ducts (particularly ducts opening radially inwards and radially outwards) for improved elastic deformation and for pressure equalization in its wall. It is possible to form the guide means 15 as a composite body composed of multiple plastic materials in layers and/or having rigid substrate parts, in order to utilize different material characteristics for optimizing the component characteristics. [0038] In a particular variant of a guide means according to FIGS. 9-11 it is formed as a sprung clip 23 having multiple arms 24, 25, 26, 27 including free ends radiating from a center Z, and wherein the arms 24-27 are accommodated for locating purposes in fixing depressions 32-35 of the brake caliper housing, and wherein the free ends 28-31 of the clip 23 each comprise one or more arms 36, 37 for resting on the circumference of the brake piston 3. Here the arms 36, 37 are preferably seated at regular intervals on the circumference intermittently elastically sprung radially inwards on the wall of the brake piston 3, thereby clamping the brake piston 3. [0039] FIG. 13 illustrates an embodiment having a sealing ring 9, wherein corresponding features are identified by corresponding reference numerals. Figure here describes, by way of example, a dual piston application, wherein K n in each case symbolizes the respective piston. All embodiments provide for a solution through a combination of multiple features. In each pairing the reference numeral 14 denotes a radially measured, maximum play between the brake piston wall 12 and the brake piston bore 13 in the housing 4. Moreover, the groove 10 is located axially offset in the housing 4 by the express offset Δ in the radial direction R to the bore axis B. Furthermore, the groove 10 has multiple peripheral irregularities (flattenings) U 1 -U n on its fundamentally annular base surface 40, staggered by an angle α of approximately ≈60° at the circumference. In conjunction with the clamped sealing ring 9 and the brake piston wall 12, the irregularities U generate an associated, radially directed force F 1 -F N . The addition of forces culminates in a resultant force component F R directed radially in the 9 o'clock position, which is also partially illustrated in FIG. 12. For additional boosting of this modal-acoustic tuning inside the brake piston guide, it is advisable to add further features to the combination, or to interchange these in order to lend the brake piston 3 a radially directed preferred orientation in the direction of the bore wall in specific modal tuning. Consequently, in accordance with the resultant force component FR on one side, the brake piston wall 12 has an especially effective modal-acoustic coupling to the bore wall of the housing 4. It goes without saying here that the unilaterally boosted coupling between the brake piston wall 12 and the brake piston bore 13 produces an enhanced relief or decoupling on the opposite side. [0040] With regard to the versions shown according to FIGS. 13 and 14, a correspondingly uniform angular orientation of the irregularity U1, U2 at P1 and P2 is presented for each piston 3, so that a uniformly directed resultant force also ensues. Resorting to positional data on the model of a notional, analog clock face, U1 here in each case coincides with location P1 roughly in a 2 o'clock position, and U2 is situated at location P2, in each case roughly in a 4 o'clock position, always in relation to the center of the respective brake piston 3. This angular orientation may be modified in fine tuning of the modal-acoustic behavior of a vehicle. Thus, it is feasible, advisable and possible for certain modified applications, for example, to specifically modify the positioning P in direction P3, P4 in order to modify the direction of the resultant force FR. Thus in the case of dual-piston applications, for example, a piston 3 arranged on the left, for example, may be acted upon from the direction of position P3 corresponding to the 8 o'clock position and from the direction P4 corresponding to the 10 o'clock position. This has the advantageous effect that the resultant forces F RK1 and F RK2 cancel one another out. These possible variations and locations are naturally further enhanced for 3-piston arrangements, without however bringing the core idea of the invention into question. [0041] The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the scope of the following claims.	A guiding system for a brake piston of a motor-vehicle disk brake comprises a brake piston, a cylindrical brake-piston bore for accommodating the brake piston in a housing in such a way that the brake piston can be axially displaced, and a ring seal supported in the housing in an axially immovable manner, which ring seal is elastically clamped between a cylindrical brake-piston wall and a recess in the brake-piston bore. In order to improve the NVH behavior in the avoidance of disturbing noises of motor-vehicle disk brakes, a reversibly elastically preloaded guiding means is clamped between the brake-piston bore and the brake-piston wall, which guiding means is supported on the housing and couples the brake piston to the brake-piston bore in such a way that the brake piston is oriented in a specific manner.	5
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of U.S. application Ser. No. 14/920,080, filed Oct. 22, 2015, which is a continuation application of and claims priority to International Application No. PCT/EP2014/058432, filed Apr. 25, 2014, which claims priority to SE 1350517-7, filed Apr. 26, 2013, each of which is incorporated by reference in its entirety herein. The present invention relates to crystal modifications of N-{(2R)-2-[({[3,3-dibutyl-7-(methyl-thio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenylethanolyl}glycine (elobixibat), more specifically crystal modifications I, IV, MeOH-1, EtOH-1, 1-PrOH-1 and 2-PrOH-1. The invention also relates to a process for the preparation of these crystal modifications and to a pharmaceutical composition comprising crystal modification IV. BACKGROUND WO 02/50051 discloses the compound 1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N′-(carboxymethyl)carbamoyl]methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine (elobixibat; IUPAC name: N-{(2R)-2-[({[3,3-dibutyl-7-(methylthio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenyl-ethanolyl}glycine). This compound is an ileal bile acid transporter (IBAT) inhibitor, which can be used in the treatment or prevention of diseases such as dyslipidemia, constipation, diabetes and liver diseases. According to the experimental section of WO 02/50051, the last synthetic step in the preparation of elobixibat consists of the hydrolysis of a tert-butoxyl ester under acidic conditions. The crude compound was obtained by evaporation of the reaction mixture under reduced pressure and purification of the residue by preparative HPLC using acetonitrile/ammonium acetate buffer (50:50) as eluent (Example 43). After freeze drying the product, no crystalline material was identified. It would be desirable to discover a form of elobixibat that is sufficiently robust to be suitable for formulation as a pharmaceutical. During crystallization studies that form the basis for this invention, it was observed using X-ray powder diffraction (XRPD) techniques that elobixibat crystallized from many solvents or mixtures of solvents by incorporating solvent molecules in its structure, thereby forming specific solvates or mixed solvates. Thus, different crystal modifications of elobixibat were obtained in many solvents or combinations of solvents. Different crystal modifications were even obtained when the same solvent was used. Further, using thermal gravimetric analysis (TGA), it was concluded that different samples of the same crystal modification may contain different amounts of solvents. Additional crystal modifications of elobixibat were obtained when the incorporated organic solvent molecules were evaporated from the crystallized solvates. Thus, the experimental work supporting the present application found that many crystal modifications of elobixibat were unstable, and/or were observed to transform into other crystal modifications. It was therefore difficult to obtain consistent results by repeating similar experiments. Different solvated crystal modifications may be revealed by using a very fast X-ray detector and withdrawing a wet sample from a slurry of the solid material to be analyzed onto a sample holder, keeping the sample at the experiment temperature and then analysing the sample quickly and repeatedly as it dries. This technique can show an initially formed solvate or mixed solvate, the desolvated modification or a mixture of the two. If more than one partially or completely desolvated crystal modification exists, there are even more possible variations of XRPD-data. It was thus a further challenge just to obtain XRPD-data for a pure crystal modification. Various crystal modifications may have disadvantages including a variable degree of crystallinity and difficulties in handling and formulating. Thus, there is a need for stable crystal modifications of elobixibat having improved properties with respect to stability, bulk handling and solubility. It is therefore an object of the present invention to provide a stable and highly crystalline crystal modification of elobixibat. SUMMARY OF THE INVENTION The invention provides various crystal modifications of elobixibat. In one aspect, the crystal modification is a monohydrate of elobixibat. A monohydrate includes 0.9-1.1 moles of water associated with a crystal per mole of elobixibat. The amount of water calculated herein excludes water adsorbed to the surface of the crystal. In certain embodiments, the monohydrate is stable for at least one year, such as at least 17 months. In another aspect, which may be related to the first aspect, the invention provides a crystalline monohydrate of elobixibat, where the crystalline form is prepared by forming an elobixibat monoalcoholate, substantially converting the monoalcoholate to an ansolvate and exposing the ansolvate to water vapor. The monoalcoholate can be a methanolate, an ethanolate, a 1-propanolate, a 2-propanolate or a mixture of these alcohols. In certain embodiments, the monohydrate cannot be formed without forming a monoalcoholate as an intermediate. The invention also includes other crystal modifications including crystal modification I and crystal modification IV, along with intermediates used to prepare these crystal modifications. The invention further provides methods of treating a condition described herein and use of the crystal modifications described herein in treating a condition described herein and in the manufacture of a medicament for the treatment of a condition described herein. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the X-ray powder diffractogram of crystal modification IV. FIG. 2 shows the X-ray powder diffractogram of crystal modification EtOH-1. FIG. 3 shows a comparison between the X-ray powder diffractograms for crystal modifications EtOH-1 (solid line, bottom) and IV (dotted line, top). FIG. 4 shows the X-ray powder diffractogram of crystal modification I. FIG. 5 shows the X-ray powder diffractogram of crystal modification IV before (bottom) and after TGA analysis (top). FIG. 6 shows the X-ray powder diffractogram of crystal modification IV obtained (from the bottom) from methanol, ethanol, 1-propanol and 2-propanol. FIG. 7 shows the X-ray powder diffractogram of crystal modifications (from the bottom) MeOH-1, EtOH-1, 1-PrOH-1 and 2-PrOH-1 obtained from methanol, ethanol, 1-propanol and 2-propanol. FIG. 8 shows the X-ray powder diffractogram of crystal modification MeOH-1. FIG. 9 shows the X-ray powder diffractogram of crystal modification 1-PrOH-1. FIG. 10 shows the X-ray powder diffractogram of crystal modification 2-PrOH-1. FIG. 11 shows the DVS mass change plot for crystal modification IV. The two curves show the % RH change (right y-axis) and the sample response in weight % (left y-axis). The pre-drying step is shown on the far left of the diagram. FIGS. 12A and 12B show a plot of water uptake as a function of % RH for crystal modification IV. The sample used in FIG. 12A was obtained from material produced on lab scale, and the sample used in FIG. 12B was obtained from GMP material produced on pilot plant scale. FIG. 13 shows the DVS mass change plot for crystal modification I. The two curves show the % RH change (right y-axis) and the sample response in weight % (left y-axis). The pre-drying step is shown on the far left of the diagram. FIG. 14 shows a plot of water uptake as a function of % RH for crystal modification I. FIG. 15 shows a micrograph of crystal modification IV, taken between slightly uncrossed polarizers and using a 10 times objective. FIG. 16 shows a micrograph of crystal modification I, taken between slightly uncrossed polarizers and using a 10 times objective. FIG. 17 shows the high-resolution X-ray powder diffractograms of crystal modification I and crystal modification IV. FIG. 18 shows the high-resolution X-ray powder diffractograms of crystal modification I, tablets comprising crystal modification I and placebo tablets. FIG. 19 shows the high-resolution X-ray powder diffractograms of crystal modification I, tablets comprising crystal modification I after 8-week storage under 40° C., 75% relative humidity and placebo tablets. FIG. 20 shows the high-resolution X-ray powder diffractograms of crystal modification IV, tablets comprising crystal modification IV and placebo tablets. FIG. 21 shows the high-resolution X-ray powder diffractograms of crystal modification IV, tablets comprising crystal modification IV after 8-week storage under 40° C., 75% relative humidity and placebo tablets. DETAILED DESCRIPTION OF THE INVENTION In a first aspect, the invention relates to crystal modification IV of elobixibat. It has surprisingly been found that this very stable crystal modification of elobixibat can be obtained, starting from what was initially thought to be the most stable dried form, crystal modification I. Crystal modification I was used as the drug substance in Phase I and II clinical trials. When this crystal modification I is slurried in ethanol or a mixture of ethanol and water at a temperature between about 0 and 70° C., such as between about 0 and 25° C., another crystal modification is gradually obtained, namely the ethanol solvate EtOH-1. This solvate has been confirmed to be a monoethanolate. Upon drying this solvate, such as under reduced pressure and elevated temperature, EtOH-1 loses its solvate molecules and turns into a partly crystalline ansolvate. When the ansolvate is subsequently exposed to moisture from the air, it readily absorbs one equivalent of water. During these two phase transformations, the crystal structure is more or less preserved. The resulting monohydrate, hereinafter referred to as crystal modification IV, was found to be stable for at least up to 17 months of storage, such as under ambient, open conditions. This crystal modification furthermore has better thermodynamic stability and a higher, more consistent degree of crystallinity than crystal modification I and other, less crystalline forms of elobixibat. It was thereafter discovered that elobixibat behaves similarly in other alcohols, such as methanol, 1-propanol and 2-propanol, or a 50:50 volume mixture of alcohol and water at room temperature. Under these conditions, the solvates MeOH-1, 1-PrOH-1 and 2-PrOH-1, which are substantially isostructural with EtOH-1, may be obtained from a slurry. The alcohol solvates thus formed behave similarly to EtOH-1, in that they form an intermediate as they begin to lose their solvate molecules and then, when the alcohol has been substantially evaporated off, absorb water and transform to modification IV. FIG. 6 shows X-ray powder diffraction data for modification IV, obtained from different alcohols. The isolation of this stable crystal modification IV was not straightforward. Although crystal modification IV is a monohydrate, it cannot be obtained directly from crude elobixibat or crystal modification I, because when these are stirred in a mixture of water and alcohol, the alcohol solvate (MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1) is formed instead. The alcohol solvate is believed to be the thermodynamically more stable crystal modification under these conditions. Interestingly, the alcohol solvate does not spontaneously transform into crystal modification IV either—not even when exposed to 100% relative humidity—if the alcohol molecules are not first removed, for example by drying, from the crystal structure of the solvate. In one embodiment, the invention relates to crystal modification IV having an X-ray powder diffraction (XRPD) pattern, obtained with CuKα1-radiation, with at least specific peaks at ° 2θ positions 6.3±0.2 and/or 19.4±0.2. In another embodiment, the invention relates to crystal modification IV having an XRPD pattern, obtained with CuKα1-radiation, with specific peaks at ° 2θ positions 6.3±0.2 and 19.4±0.2 and one or more of the characteristic peaks: 10.2±0.2, 10.5±0.2, 9.4±0.2, 9.5±0.2, 12.5±0.2, 14.6±0.2, 15.6±0.2, and 23.3±0.2. In another embodiment, the invention relates to crystal modification IV having an XRPD pattern, obtained with CuKα1-radiation, with specific peaks at ° 2θ positions 6.3±0.2, 19.4±0.2, 10.2±0.2, 10.5±0.2, 9.4±0.2, and 9.5±0.2. In another embodiment, the invention relates to crystal modification IV having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions 6.3±0.2, 19.4±0.2, 10.2±0.2, 10.5±0.2, 9.4±0.2, 9.5±0.2, 12.5±0.2, 14.6±0.2, 15.6±0.2, 23.3±0.2, and one or more of 8.3±0.2, 11.3±0.2, 13.4±0.2, 13.9±0.2, 16.3±0.2, 16.6±0.2, 18.2±0.2, 18.8±0.2, 19.1±0.2, 19.3±0.2, 19.7±0.2, 19.8±0.2, 20.5±0.2, 21.0±0.2, 21.3±0.2, 21.4±0.2, 22.6±0.2, 22.9 0.2, 23.1±0.2, 23.9±0.2, 24.5±0.2, 24.7±0.2, 25.0±0.2, 25.2±0.2, 25.4±0.2, 25.7±0.2, 26.7±0.2, 26.9±0.2, 28.3±0.2, and 28.9±0.2. According to one embodiment the invention relates to crystal modification IV having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.3±0.2, 8.3±0.2, 9.4±0.2, 9.5±0.2, 10.2±0.2, 10.5±0.2, 11.3±0.2, 12.5±0.2, 13.4±0.2, 13.9±0.2, 14.6±0.2, 15.6±0.2, 16.3±0.2, 16.6±0.2, 18.2±0.2, 18.8±0.2, 19.1±0.2, 19.3±0.2, 19.4±0.2, 19.7±0.2, 19.8±0.2, 20.5±0.2, 21.0±0.2, 21.3±0.2, 21.4±0.2, 22.6±0.2, 22.9±0.2, 23.1±0.2, 23.3±0.2, 23.9±0.2, 24.5±0.2, 24.7±0.2, 25.0±0.2, 25.2±0.2, 25.4±0.2, 25.7±0.2, 26.7±0.2, 26.9±0.2, 28.3±0.2, and 28.9±0.2. In yet another embodiment, the invention relates to crystal modification IV having an XRPD pattern, obtained with CuKα1-radiation, substantially as shown in FIG. 1 . In a second aspect, the invention relates to crystal modification EtOH-1 of elobixibat. In one embodiment, the invention relates to crystal modification EtOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions 6.1±0.2 and 18.9±0.2 or having characteristic peaks at ° 2θ positions 6.1±0.2 and 18.9±0.2 and one or more of the characteristic peaks: 10.1±0.2, 14.5±0.2, 18.4±0.2, 19.1±0.2, 20.7±0.2, 10.4±0.2, 13.1±0.2, and 11.1±0.2. In another embodiment, the invention relates to crystal modification EtOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.1±0.2, 18.9±0.2, 10.1±0.2, 14.5±0.2, 18.4±0.2, 19.1±0.2, 20.7±0.2, 10.4±0.2, 13.1±0.2, 11.1±0.2 and one or more of 8.0±0.2, 9.3±0.2, 12.2±0.2, 13.7±0.2, 15.1±0.2, 15.3±0.2, 15.9±0.2, 17.2±0.2, 17.8±0.2, 20.3±0.2, 21.2±0.2, 22.0±0.2, 22.2±0.2, 22.5±0.2, 23.6±0.2, 24.0±0.2, 24.5±0.2, 24.7±0.2, 25.2±0.2, and 26.3±0.2. In another embodiment, the invention relates to crystal modification EtOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.1±0.2, 8.0±0.2, 9.3±0.2, 10.1±0.2, 10.4±0.2, 11.1±0.2, 12.2±0.2, 13.1±0.2, 13.7±0.2, 14.5±0.2, 15.1±0.2, 15.3±0.2, 15.9±0.2, 17.2±0.2, 17.8±0.2, 18.4±0.2, 18.9±0.2, 19.1±0.2, 20.3±0.2, 20.7±0.2, 21.2±0.2, 22.0±0.2, 22.2±0.2, 22.5±0.2, 23.6±0.2, 24.0±0.2, 24.5±0.2, 24.7±0.2, 25.2±0.2, and 26.3±0.2. In yet another embodiment, the invention relates to crystal modification EtOH-1 having an XRPD pattern, obtained with CuKα1-radiation, substantially as shown in FIG. 2 . In a third aspect, the invention relates to crystal modification MeOH-1 of elobixibat. In one embodiment, the invention relates to crystal modification MeOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions 6.2±0.2 and 18.9±0.2 or having characteristic peaks at ° 2θ positions 6.2±0.2 and 18.9±0.2 and one or more of the characteristic peaks: 10.1±0.2, 14.6±0.2, 18.6±0.2, 19.1±0.2, 22.2±0.2, 24.7±0.2, 12.3±0.2, 13.3±0.2, and 16.1±0.2. In another embodiment, the invention relates to crystal modification MeOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.2±0.2, 18.9±0.2, 10.1±0.2, 14.6±0.2, 18.6±0.2, 19.1±0.2, 22.2±0.2, 24.7±0.2, 12.3±0.2, 13.3±0.2, 16.1±0.2 and one or more of 8.1±0.2, 9.3±0.2, 10.5±0.2, 10.9±0.2, 13.0±0.2, 14.4±0.2, 15.8±0.2, 17.6±0.2, 20.3±0.2, 20.7±0.2, 21.0±0.2, 22.7±0.2, 24.0±0.2, 24.3±0.2 and 26.1±0.2. In another embodiment, the invention relates to crystal modification MeOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.2±0.2, 8.1±0.2, 9.3±0.2, 10.1±0.2, 10.5±0.2, 10.9±0.2, 12.3±0.2, 13.0±0.2, 13.3±0.2, 14.4±0.2, 14.6±0.2, 15.8±0.2, 16.1±0.2, 17.6±0.2, 18.6±0.2, 18.9±0.2, 19.1±0.2, 20.3±0.2, 20.7±0.2, 21.0±0.2, 22.2±0.2, 22.7±0.2, 24.0±0.2, 24.3±0.2, 24.7±0.2, and 26.1±0.2. In yet another embodiment, the invention relates to crystal modification MeOH-1 having an XRPD pattern, obtained with CuKα1-radiation, substantially as shown in FIG. 8 . In a fourth aspect, the invention relates to crystal modification 1-PrOH-1 of elobixibat. In one embodiment, the invention relates to crystal modification 1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 or having characteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 and one or more of the characteristic peaks: 10.0±0.2, 14.4±0.2, 18.3±0.2, 18.8±0.2, 20.5±0.2, 10.3±0.2, 13.0±0.2, and 11.0±0.2. In another embodiment, the invention relates to crystal modification 1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.1±0.2, 19.0±0.2, 10.0±0.2, 14.4±0.2, 18.3±0.2, 18.8±0.2, 20.5±0.2, 10.3±0.2, 13.0±0.2, 11.0±0.2 and one or more of 7.9±0.2, 9.2±0.2, 12.1±0.2, 13.6±0.2, 15.0±0.2, 15.3±0.2, 15.8±0.2, 17.1±0.2, 17.6±0.2, 20.2±0.2, 21.1±0.2, 21.9±0.2, 22.1±0.2, 22.4±0.2, 23.5±0.2, 23.8±0.2, 24.3±0.2, 24.5±0.2, 25.4±0.2, and 26.2±0.2. In another embodiment, the invention relates to crystal modification 1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.1±0.2, 7.9±0.2, 9.2±0.2, 10.0±0.2, 10.3±0.2, 11.0±0.2, 12.1±0.2, 13.0±0.2, 13.6±0.2, 14.4±0.2, 15.0±0.2, 15.3±0.2, 15.8±0.2, 17.1±0.2, 17.6±0.2, 18.3±0.2, 18.5±0.2, 18.8±0.2, 19.0±0.2, 19.4±0.2, 20.2±0.2, 20.5±0.2, 21.1±0.2, 21.9±0.2, 22.1±0.2, 22.4±0.2, 23.1±0.2, 23.5±0.2, 23.8±0.2, 24.3±0.2, 24.5±0.2, 25.4±0.2, 26.0±0.2 and 26.2±0.2. In yet another embodiment, the invention relates to crystal modification 1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, substantially as shown in FIG. 9 . In a fifth aspect, the invention relates to crystal modification 2-PrOH-1 of elobixibat. In one embodiment, the invention relates to crystal modification 2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 or having characteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 and one or more of the characteristic peaks: 10.0±0.2, 14.4±0.2, 18.3±0.2, 18.8±0.2, 20.5±0.2, 10.3±0.2, 12.9±0.2, and 11.0±0.2. In another embodiment, the invention relates to crystal modification 2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.1±0.2, 19.0±0.2, 10.0±0.2, 14.4±0.2, 18.3±0.2, 18.8±0.2, 20.5±0.2, 10.3±0.2, 12.9±0.2, 11.0±0.2 and one or more of 9.1±0.2, 12.1±0.2, 13.6±0.2, 14.9±0.2, 15.2±0.2, 15.7±0.2, 17.1±0.2, 17.6±0.2, 18.5±0.2, 19.4±0.2, 20.2±0.2, 21.1±0.2, 21.7±0.2, 22.1±0.2, 22.3±0.2, 23.1±0.2, 23.4±0.2, 23.7±0.2, 24.1±0.2, 24.4±0.2, 24.6±0.2, 25.1±0.2, 25.4±0.2, 25.9±0.2, 26.2±0.2, 27.4±0.2 and 29.2±0.2. In another embodiment, the invention relates to crystal modification 2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 6.1±0.2, 9.1±0.2, 10.0±0.2, 10.3±0.2, 11.0±0.2, 12.1±0.2, 12.9±0.2, 13.6±0.2, 14.4±0.2, 14.9±0.2, 15.2±0.2, 15.7±0.2, 17.1±0.2, 17.6±0.2, 18.2±0.2, 18.5±0.2, 18.9±0.2, 19.0±0.2, 19.4±0.2, 20.2±0.2, 20.5±0.2, 21.1±0.2, 21.7±0.2, 22.1±0.2, 22.3±0.2, 23.1±0.2, 23.4±0.2, 23.7±0.2, 24.1±0.2, 24.4±0.2, 24.6±0.2, 25.0±0.2, 25.4±0.2, 25.9±0.2, 26.2±0.2, 27.4±0.2 and 29.2±0.2. In yet another embodiment, the invention relates to crystal modification 2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, substantially as shown in FIG. 10 . In a sixth aspect, the invention relates to crystal modification I of elobixibat. In one embodiment, the invention relates to crystal modification I having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions 5.2±0.2 and/or 10.0±0.2. In another embodiment, the invention relates to crystal modification I having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 5.2±0.2 and 10.0±0.2 and one or more of the characteristic peaks: 4.9±0.2, 6.0±0.2, 7.6±0.2, 10.5±0.2, 11.3±0.2, 18.8±0.2, 20.4±0.2, and 22.9±0.2. In another embodiment, the invention relates to crystal modification I having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 5.2±0.2, 10.0±0.2, 4.9±0.2, 6.0±0.2, 7.6±0.2, 10.5±0.2 and 11.3±0.2. In another embodiment, the invention relates to crystal modification I having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 5.2±0.2, 10.0±0.2, 4.9±0.2, 6.0±0.2, 7.6±0.2, 10.5±0.2, 11.3±0.2, 18.8±0.2, 20.4±0.2, 22.9±0.2, and one or more of 3.1±0.2, 4.4±0.2, 7.4±0.2, 7.8±0.2, 8.2±0.2, 12.4±0.2, 13.3±0.2, 13.5±0.2, 14.6±0.2, 14.9±0.2, 16.0±0.2, 16.6±0.2, 16.9±0.2, 17.2±0.2, 17.7±0.2, 18.0±0.2, 18.3±0.2, 19.2±0.2, 19.4±0.2, 20.1±0.2, 20.7±0.2, 20.9±0.2, 21.1±0.2, 21.4±0.2, 21.8±0.2, 22.0±0.2, 22.3±0.2, 23.4±0.2, 24.0±0.2, 24.5±0.2, 24.8±0.2, 26.4±0.2, '27.1±0.2 and 27.8±0.2. In another embodiment, the invention relates to crystal modification I having an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 3,1±0.2, 4.4±0.2, 4.9±0.2, 5.2±0.2, 6.0±0.2, 7.4±0.2, 7.6±0.2, 7.8±0.2, 8.2±0.2, 10.0±0.2, 10.5±0.2, 11.3±0.2, 12.4±0.2, 13.3±0.2, 13.5±0.2, 14.6±0.2, 14.9±0.2, 16.0±0.2, 16.6±0.2, 16.9±0.2, 17.2±0.2, 17.7±0.2, 18.0±0.2, 18.3±0.2, 18.8±0.2, 19.2±0.2, 19.4±0.2, 20.1±0.2, 20.4±0.2, 20.7±0.2, 20.9±0.2, 21.1±0.2, 21.4±0.2, 21.8±0.2, 22.0±0.2, 22.3±0.2, 22.9±0.2, 23.4±0.2, 24.0±0.2, 24.5±0.2, 24.8±0.2, 26.4±0.2. '27.1±0.2 and 27.8±0.2. In yet another embodiment, the invention relates to crystal modification I having an XRPD pattern, obtained with CuKα1-radiation, substantially as shown in FIG. 4 . An advantage with crystal modification IV is that it is more thermodynamically stable at normal conditions (21° C., 10-30% relative humidity) than crystal modification I and other crystal modifications of elobixibat obtained from methanol, ethanol, 1-propanol or 2-propanol, or from mixtures of any of these alcohols and water. This allows for a stable and secure manufacturing process of the drug substance and drug formulation. Certain forms of elobixibat, such as crystal modification I of elobixibat, contain a non-stoichiometric amount of water. In such forms, the amount of water may vary (e.g., dependent on the relative humidity of the air, or between different batches). In contrast, crystal modification IV is a stoichiometric monohydrate, i.e. it contains about one mole of water per mole of substance (typically from 0.9-1.1 moles of water per mole of substance, not including water adsorbed to the surface of a crystal). This gives crystal modification IV a more stable weight at varying relative humidity. Crystal modification IV is a highly crystalline monohydrate, which can be produced by a controlled transformation process via the ethanol solvate EtOH-1 or via the isostructural alcohol solvates MeOH-1, 1-PrOH-1 and 2-PrOH-1. The crystal structure of EtOH-1 remains similar when the ethanol is evaporated and replaced by water. Further, the relatively stable degree of crystallinity of crystal modification IV results in a reproducible solubility of the compound. This is of special importance for compounds that are to be used in pharmaceutical preparations, where each tablet or capsule containing the active pharmaceutical ingredient should have the same pharmacological properties. Thus, crystal modification IV is more favourable for preparing pharmaceutical formulations of elobixibat than other crystal modifications of elobixibat discovered to date. Yet another advantage with crystal modification IV is that the crystal habit is more three dimensional compared to the crystal modification I, which is more two dimensional (needle shaped). This gives crystal modification IV advantageous properties with regard to bulk handling and formulation. For instance, there is reduced or even no need to sieve the material, for example to break such crystals, and it can more easily be mixed with excipients during formulation. In another aspect, the invention relates to a process for the preparation of crystal modification IV. This process involves the preparation and isolation of crystal modification EtOH-1, or one of the isostructural alcohol solvates MeOH-1, 1-PrOH-1 and 2-PrOH-1, from either crude or pure elobixibat. In one embodiment, the process comprises the steps of: a) preparing a saturated solution of elobixibat in alcohol or a mixture of alcohol and water in a vessel; b) adding an excess of elobixibat to the saturated solution of step a) so as to obtain a slurry; c) maintaining stirring of the slurry, optionally at about 5 to 25° C., preferably 20 to 25° C. for a period of several hours up to several days or even a week or more; d) recovering the solid obtained in step c), followed by drying the solid in vacuum until removal of substantially all alcohol; and e) exposing the dry solid obtained in step d) to moisture from the air. The crude or pure starting material in step a) is amorphous elobixibat or another crystal modification of elobixibat. In certain embodiments, elobixibat is essentially free from solvents other than water. In a preferred embodiment, the starting material is crystal modification I, which is a relatively stable crystal modification of elobixibat. Crystal modification I can be obtained from crude, amorphous elobixibat, as described in the experimental section. Its X-ray powder diffractogram is showed in FIG. 4 . In certain embodiments, the saturated solution of elobixibat used in step a) is free from any solvents except methanol, ethanol, 1-propanol, 2-propanol and water, such as less than 0.5% w/w solvents except methanol, ethanol, 1-propanol, 2-propanol and water. If a mixture of methanol and water, ethanol and water, 1-propanol and water or 2-propanol and water is used, the amount of methanol, ethanol, 1-propanol or 2-propanol should be at least 5% w/w in certain embodiments. Most preferably, the solvent is at least 90% or even 100% w/w methanol, ethanol, 1-propanol or 2-propanol. The solid obtained in step c) is crystal modification MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1. It is believed that in methanol, ethanol, 1-propanol or 2-propanol, or in a mixture of methanol, ethanol, 1-propanol or 2-propanol and water, crystal modification MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1 is the most thermodynamically stable form. Thus, when the suspension of step b) is stirred at about 5 to 25° C., such as 20-25° C. (preferably for methanol), for a longer period of time, at such temperature, MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1 will crystallize. Crystal modification MeOH-1 is a methanol solvate, crystal modification EtOH-1 is an ethanol solvate, crystal modification 1-PrOH-1 is a 1-propanol solvate and crystal modification 2-PrOH-1 is a 2-propanol solvate. When these solvates are dried under reduced pressure and elevated temperature, they lose their alcohol molecules and turn into an ansolvate. In order to obtain a full transformation from the alcohol solvate form to the monohydrate form, MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1 must be dried, so as to substantially remove the alcohol embedded in the crystals. Preferably, the solid is dried under vacuum at elevated temperatures, such as about 50° C., or such as about 65° C. When the ansolvate crystals are exposed to moisture from the air, water molecules are absorbed and a monohydrate is formed, crystal modification IV. Absorption of water takes place at relative humidity as low as 10%. For reproducible results and high degree of crystallinity, it is preferred that the anhydrate crystals are exposed to air at a relative humidity of 20-60% at 25° C. By means of thermal gravimetric analysis, differential scanning calorimetry, Karl Fischer titration and Dynamic Vapor Sorption analysis, it has been shown that crystal modification IV is a monohydrate. Alternatively, crystal modification IV can be prepared by adding seed crystals to a saturated solution of elobixibat in methanol, ethanol, 1-propanol or 2-propanol or a mixture of methanol, ethanol, 1-propanol or 2-propanol and water. Thus, in another embodiment, the process comprises the steps of: a) preparing an supersaturated solution of elobixibat in alcohol or a mixture of alcohol and water, in a vessel; b) adding seed crystals to the supersaturated solution of step a); c) maintaining stirring until a solid is obtained; d) recovering the solid obtained in step c), followed by drying the solid in vacuum until removal of the alcohol; and e) exposing the dry solid obtained in step d) to moisture from the air. The crude or pure starting material in step a) is amorphous elobixibat or another crystal modification of elobixibat which in certain embodiments is free from solvents other than alcohol and water. In certain embodiments, the supersaturated solution of elobixibat used in step a) is free from any solvents except alcohol and water, such as less than 0.5% solvents except alcohol and water. If a mixture of alcohol and water is used, the amount of alcohol should be at least 5% w/w in certain embodiments. Preferably, the solvent is methanol, ethanol, 1-propanol or 2-propanol. The supersaturated solution can be prepared by dissolving starting material in warm methanol, ethanol, 1-propanol or 2-propanol or a warm mixture of methanol, ethanol, 1-propanol or 2-propanol and water, and then cooling the resulting solution. The warm solvent preferably has an initial temperature of about 40 to 45° C., and the solution is then cooled to a temperature such as about 25° C. The seed crystals should be of crystal modification IV. The addition of seed crystals will accelerate the formation and crystallization of MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1. The stirring time in step c) can therefore be considerably shorter, such as 15 hours, or such as 10 hours. The stirring can be maintained at a lower temperature, such as 5 to 10° C., or such as 0 to 5° C. Interestingly, even though crystal modification IV is a monohydrate, it cannot be obtained directly from crystal modification I when stirred in a mixture of water and methanol, ethanol, 1-propanol or 2-propanol. In such a mixture, crystal modification I transforms into the alcohol solvate MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1, respectively, all of which are believed to be a thermodynamically more stable crystal modification than crystal modification I under these conditions. Surprisingly, when the formed MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1 subsequently is exposed to 100% relative humidity, it still does not transform into the monohydrate. This shows that the alcohol molecules must be substantially removed from the crystal structure before water molecules can enter and change the structure to crystal modification IV. When crystal modification IV is stirred in methanol, ethanol, 1-propanol or 2-propanol, or in a mixture of methanol, ethanol, 1-propanol or 2-propanol and water, it transforms again into MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1. It is speculated that this transformation occurs within only a few minutes. This is likely a result of the high degree of similarity between the XRPD patterns for crystal modifications MeOH-1, EtOH-1, 1-PrOH-1, 2-PrOH-1 and IV (see FIG. 3 and FIG. 7 ). Since the patterns are so similar, it is believed, albeit without reliance on such theory, that the transformation may occur without dissolution and subsequent re-crystallization, but rather by a rearrangement in the solid state. Elobixibat is an ileal bile acid transporter (IBAT) inhibitor. The ileal bile acid transporter (IBAT) is the main mechanism for re-absorption of bile acids from the GI tract. Partial or full blockade of that IBAT mechanism will result in lower concentration of bile acids in the small bowel wall, portal vein, liver parenchyma, intrahepatic biliary tree, and extrahepatic biliary tree, including the gall bladder. Diseases which may benefit from partial or full blockade of the IBAT mechanism may be those having, as a primary pathophysiological defect, symptoms of excessive concentration of bile acids in serum and in the above organs. Thus, in another aspect, the invention also relates to crystal modification IV of elobixibat for use in therapy. Crystal modification IV is useful in the prophylaxis or treatment of hypercholesterolemia, dyslipidemia, metabolic syndrome, obesity, disorders of fatty acid metabolism, glucose utilization disorders, disorders in which insulin resistance is involved, type 1 and type 2 diabetes mellitus, liver diseases, diarrhoea during therapy comprising an IBAT inhibitor compound, constipation including chronic constipation, e.g. functional constipation, including chronic constipation and constipation predominant irritable bowel syndrome (IBS-C). Treatment and prophylaxis of constipation is described in WO 2004/089350. Further potential diseases to be treated with the crystal modification IV are selected from the group consisting of liver parenchyma, inherited metabolic disorders of the liver, Byler syndrome, primary defects of bile acid (BA) synthesis such as cerebrotendinous xanthomatosis, secondary defects such as Zellweger's syndrome, neonatal hepatitis, cystic fibrosis (manifestations in the liver), ALGS (Alagilles syndrome), progressive familial intrahepatic cholestasis (PFIC), autoimmune hepatitis, primary biliary cirrhosis (PBC), liver fibrosis, non-alcoholic fatty liver disease, NAFLD/NASH, portal hypertension, general cholestasis such as in jaundice due to drugs or during pregnancy, intra- and extrahepatic cholestasis such as hereditary forms of cholestasis such as PFIC1, primary sclerosing cholangitis (PSC), gall stones and choledocholithiasis, malignancy causing obstruction of the biliary tree, symptoms (scratching, pruritus) due to cholestasis/jaundice, pancreatitis, chronic autoimmune liver disease leading to progressive cholestasis, pruritus of cholestatic liver disease and disease states associated with hyperlipidaemic conditions. Other diseases to be treated with the crystal modification IV are selected from the group consisting of hepatic disorders and conditions related thereto, fatty liver, hepatic steatosis, non-alcoholic steatohepatitis (NASH), alcoholic hepatitis, acute fatty liver, fatty liver of pregnancy, drug-induced hepatitis, iron overload disorders, hepatic fibrosis, hepatic cirrhosis, hepatoma, viral hepatitis and problems in relation to tumours and neoplasmas of the liver, of the biliary tract and of the pancreas. Thus, in one embodiment, the invention relates to crystal modification IV of elobixibat for use in the treatment and/or prophylaxis of a disease or disorder as listed above. In another embodiment, the invention relates to the use of crystal modification IV of elobixibat in the manufacture of a medicament for the treatment and/or prophylaxis of a disease or disorder as listed above. In yet another embodiment, the invention relates to a method of treatment and/or prophylaxis of a disease or disorder as listed above in a warm-blooded animal, comprising administering an affective amount of crystal modification IV of elobixibat to a warm-blooded animal in need of such treatment and/or prophylaxis. Another aspect of the invention relates to a pharmaceutical composition comprising an effective amount of crystal modification IV, in association with a pharmaceutically acceptable diluent or carrier. Yet another aspect of the invention relates to the use of crystal modification IV in the preparation of a pharmaceutical composition, comprising admixing crystal modification IV with a pharmaceutically acceptable diluent or carrier. The pharmaceutical composition may further comprise at least one other active substance, such as an active substance selected from an IBAT inhibitor; an enteroendocrine peptide or enhancer thereof; a dipeptidyl peptidase-IV inhibitor; a biguanidine; an incretin mimetic; a thiazolidinone; a PPAR agonist; a HMG Co-A reductase inhibitor; a bile acid binder; a TGR5 receptor modulator; a member of the prostone class of compounds; a guanylate cyclase C agonist; a 5-HT4 serotonin agonist; or a pharmaceutically acceptable salt of any one these active substances. Examples of such combinations are also described in WO2012/064268. Crystal modification IV will normally be administered to a warm-blooded animal at a unit dose within the range of 5 to 5000 mg per square meter body area, i.e. approximately 0.1 to 100 mg/kg or 0.01 to 50 mg/kg, and this normally provides a therapeutically-effective dose. A unit dose form, such as a tablet or capsule, will usually contain about 1 to 250 mg of active ingredient, such as about 1 to 100 mg, or about 5 to 50 mg, e.g. about 1 to 20 mg. The daily dose can be administered as a single dose or divided into one, two, three or more unit doses. An orally administered daily dose of an IBAT inhibitor is preferably within 0.1 to 1000 mg, more preferably 1 to 100 mg, such as 5 to 15 mg. The dosage required for the therapeutic or prophylactic treatment will depend on the route of administration, the severity of the disease, the age and weight of the patient and other factors normally considered by the attending physician when determining the individual regimen and dosage levels appropriate for a particular patient. Definitions The term “crystal modification” refers to a crystalline solid phase of an organic compound. A crystal modification can be either a solvate or an ansolvate. The term “solvate” refers to a crystalline solid phase of an organic compound, which has solvent molecules incorporated into its crystal structure. A “hydrate” is a solvate wherein the solvent is water, whereas a “mixed solvate” is a solvate containing molecules from more than one solvent. The term “slurry” refers to a saturated solution to which an overshoot of solid is added, thereby forming a mixture of solid and saturated solution, a “slurry”. As used herein, the terms “treatment,” “treat,” and “treating” refer to reversing, alleviating, delaying the onset of, or inhibiting the progress of a disease or disorder, or one or more symptoms thereof, as described herein. In some embodiments, treatment may be administered after one or more symptoms have developed. In other embodiments, treatment may be administered in the absence of symptoms. For example, treatment may be administered to a susceptible individual prior to the onset of symptoms (e.g., in light of a history of symptoms and/or in light of genetic or other susceptibility factors). Treatment may also be continued after symptoms have resolved, for example to prevent or delay their recurrence. When reference is made herein to a crystalline compound, preferably the crystallinity as estimated by X-ray powder diffraction data is greater than about 70%, such as greater than about 80%, particularly greater than about 90%, more particularly greater than about 95%. In embodiments of the invention, the degree of crystallinity as estimated by X-ray powder diffraction data is greater than about 98%, preferably greater than about 99%, wherein the % crystallinity refers to the percentage by weight of the total sample mass which is crystalline. Preferably a crystal modification according to the invention is substantially free from other crystal modifications of the compound. Preferably, the described crystal modifications of elobixibat includes less than, for example, 20%, 15%, 10%, 5%, 3%, or particularly, less than 1% by weight of other crystal modifications of elobixibat. Thus, preferably, the purity of the described crystal modifications of elobixibat is >80%, >85%, >90%, >95%, >97%, or particularly >99%. The invention will now be described by the following examples which do not limit the invention in any respect. All cited documents and references are incorporated by reference. Abbreviations cr. mod. crystal modification EtOH ethanol h hour(s) HDPE high density polyethylene LDPE low density polyethylene MeOH methanol min. minute(s) 1-PrOH 1-propanol 2-PrOH 2-propanol EXPERIMENTAL METHODS X-Ray Powder Diffraction (XRPD) Analysis Dry samples were lightly ground in an agate mortar, if needed, and were then smeared out on a sample holder. Slurry samples were added to the sample holder as wet and were analyzed both wet and dry. XRPD data were collected on a cut Silicon Zero Background Holder (ZBH) or on a Porous Alumina Filter Sample Holder, using a PANalytical X'Pert Pro diffractometer, equipped with an X'celerator or a PIXcel detector. The sample was spun during analysis and Cu-radiation was used. The following experimental settings were used: Tube tension and current: 40 kV, 50 mA Wavelength alpha1 (CuKα1): 1.5406 Å Wavelength alpha2 (CuKα2): 1.5444 Å Wavelength alpha1 and alpha2 mean (CuKα): 1.5418 Å Start angle [2 theta]: 1-4° End angle [2 theta]: 30-40° Analysis time: 50 s (“1 min scan”), 125 s (“2 min scan”), 192 s (“3 min scan”), 397 s (“6 min scan”), 780 s (“13 min scan”), 1020 s (“17 min scan”), 4560 s (“1 h scan”) Unless indicated otherwise, when calculating the peak positions from the XRPD-data, the data was first stripped from the contribution from CuKα2 and was then corrected against an internal standard (Al 2 O 3 ). It is known in the art that an X-ray powder diffraction pattern may be obtained having one or more measurement errors depending on measurement conditions (such as equipment, sample preparation or machine used). In particular, it is generally known that intensities in an XRPD pattern may fluctuate depending on measurement conditions and sample preparation. For example, persons skilled in the art of XRPD will realise that the relative intensities of peaks may vary according to the orientation of the sample under the test and on the type and setting of the instrument used. The skilled person will also realise that the position of reflections can be affected by the precise height at which the sample sits in the diffractometer and the zero calibration of the diffractometer. The surface planarity of the sample may also have a small effect. Hence a person skilled in the art will appreciate that the diffraction pattern presented herein is not to be construed as absolute and any crystalline form that provides a powder diffraction pattern substantially identical to those disclosed herein fall within the scope of the present disclosure (for further information, see R. Jenkins and R. L. Snyder, “Introduction to X-ray powder diffractomety”. John Wiley & Sons, 1996), Thermogravimetric Analysis (TGA) Approximately 1-5 mg of sample was added to a tared Platinum cup which was then placed in the weighting position of a Perkin-Elmer Pyris 1 TGA analyzer. The furnace was raised and the starting weight of the sample was recorded. The heating program was then started. The sample was heated at a rate of 10° C./min, starting at 25° C. and ending at 90-300° C., depending on where a constant temperature could be attained. The sample was purged with dry nitrogen gas during analysis. Dynamic Vapor Sorption (DVS) Approximately 15-20 mg of the sample was weighed into a quartz receptacle, which was then released of static electricity by exposing it to a radioactive source. The quartz receptacle was then positioned in a Surface Measurements System Ltd DVS Advantage instrument. The sample was dried with dry nitrogen gas until a dm/dt below 0.002% per minute was reached. The instrument was running in dm/dt-mode using a dm/dt window of 5 minutes, a minimum stage time of 10 minutes and a maximum stage time of 360 minutes. The sample was then subjected to two consecutive sorption-desorption cycles, using d/m/dt-mode parameters above, and each cycle running from 0-95-0% relative humidity (% RH). One cycle consisted of 20 steps, those between 0-90% RH were taken in 10% RH each. Differential Scanning Calorimetry (DSC) Approximately 2 mg of a sample was weighed into an aluminium DSC pan sealed non-hermetically with an aluminium lid (sealed pan). The sample was then loaded into a Perkin-Elmer Diamond DSC cooled and held at 30° C. Once a sufficiently stable heat-flow response was obtained, the sample was heated to 150° C. at a scan rate of 5° C./min and the resulting heat flow response monitored. A nitrogen purge was used to prevent thermally induced oxidation of the sample during heating and also to reduce the thermal lag through the sample to increase the instrument sensitivity. Prior to analysis, the instrument was temperature and heat-flow calibrated using an indium reference standard. For cryo-DSC experiments, the Perkin-Elmer Diamond DSC was cooled and held at 5° C., and the sample was then analysed from 5 to 200° C. at a scan rate of 10° C./minute. The starting material 1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N-(t-butoxycarbonyl methyl)carbamoyl]methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine can be prepared as described in WO002/50051. EXAMPLES Example 1 Preparation of Crystal Modification I Toluene (11.78 L) was charged to a 20 L round-bottom flask with stirring and 1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N′-(t-butoxycarbonylmethyl)carbamoyl]-methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine (2.94 kg) was added. Formic acid (4.42 L) was added to the reaction mass at 25-30° C. The temperature was raised to 115-120° C. and stirred for 6 hours. The reaction was monitored by HPLC to assure that not more than 1% of the starting material remained in the reaction mass. The reaction mass was cooled to 40-43° C. Purified water (11.78 L) was added while stirring. The reaction mass was further cooled to 25-30° C. and stirred for 15 min. The layers were separated and the organic layer was filtered through a celite bed (0.5 kg in 3 L of toluene) and the filtrate was collected. The celite bed was washed with toluene (5.9 L), the filtrates were combined and concentrated at 38-40° C. under vacuum. The reaction mass was then cooled to 25-30° C. to obtain a solid. Ethanol (3.7 L) was charged to a clean round-bottom flask with stirring, and the solid obtained in the previous step was added. The reaction mass was heated to 40-43° C. and stirred at this temperature for 30 min. The reaction mass was then cooled to 25-30° C. over a period of 30 min., and then further cooled to 3-5° C. over a period of 2 h, followed by stirring at this temperature for 14 h. Ethanol (3.7 L) was charged to the reaction mass with stirring, while maintaining the temperature at 0-5° C., and the reaction mass was then stirred at this temperature for 1 h. The material was then filtered and washed with ethanol (1.47 L), and vacuum dried for 30 min. The material was dried in a vacuum tray dryer at 37-40° C. for 24 h under nitrogen atmosphere. The material was put in clean double LDPE bags under nitrogen atmosphere and stored in a clean HDPE drum. Yield 1.56 kg. Crystal modification I has an XRPD pattern, obtained with CuKα1-radiation, with characteristic peaks at ° 2θ positions: 3.1±0.2, 4.4±0.2, 4.9±0.2, 5.2±0.2, 6.0±0.2, 7.4±0.2, 7.6±0.2, 7.8±0.2, 8.2±0.2, 10.0±0.2, 10.5±0.2, 11.3±0.2, 12.4±0.2, 13.3±0.2, 13.5±0.2, 14.6±0.2, 14.9±0.2, 16.0±0.2, 16.6±0.2, 16.9±0.2, 17.2±0.2, 17.7±0.2, 18.0±0.2, 18.3±0.2, 18.8±0.2, 19.2±0.2, 19.4±0.2, 20.1±0.2, 20.4±0.2, 20.7±0.2, 20.9±0.2, 21.1±0.2, 21.4±0.2, 21.8±0.2, 22.0±0.2, 22.3±0.2, 22.9±0.2, 23.4±0.2, 24.0±0.2, 24.5±0.2, 24.8±0.2, 26.4±0.2, '27.1±0.2 and 27.8±0.2. The X-ray powder diffractogram is shown in FIG. 4 . Example 2 Preparation of Crystal Modification IV Via EtOH-1 Elobixibat crystal modification I (60 mg) was added to ethanol (1.0 mL) and to a mixture of ethanol and water (0.25+0.75 mL) at 21° C., so as to produce slurries. A stirring bar was then added to each vessel and the vessels were closed. The vessels were left well stirred at 21° C. for one week. The solid residue in each of the experiment vessels was sampled with a Pasteur pipette to a cut Silicon Zero Background Holder, and the samples were analyzed with two consecutive 1-minute XRPD-scans, from 1 to 40° in 2θ. After this one or more slightly longer (3 minutes and 12 seconds) XRPD analysis were performed until two consecutive and identical XRPD-diffractograms had been obtained. When the samples had been analyzed in this way, they were left in the open lab atmosphere for 1 day. Under these conditions (approximately 21° C. and 30% relative humidity) and with the small sample size, ethanol molecules evaporated from the crystal and were replaced by water thereby producing crystal modification IV. Example 3 Preparation of Crystal Modification IV Via MeOH-1 Approximately 80 mg of elobixibat crystal modification IV was added to a Chromacol vessel and then 1.0 mL of methanol and a stirring flea was added. The vessel was closed with a crimped cap, stirred for a day at 21° C. and was then sampled to a cut Silicon Zero Background Holder (ZBH) and analysed with XRPD repeatedly as the sample dried. When visually dry it was analysed with TGA and was then allowed to absorb moisture from the ambient lab atmosphere before it was re-analysed with XRPD. The XRPD-data on the wet sample is shown in FIG. 8 and after TGA-analysis in FIG. 6 . Example 4 Preparation of Crystal Modification IV Via 1-PrOH-1 99.6 mg of elobixibat crystal modification IV was added to a Chromacol vessel and then 1.0 mL of 1-propanol and a stirring flea was added. The vessel was closed with a crimped cap, stirred for a day at 21° C. and was then sampled to a cut Silicon Zero Background Holder (ZBH) and analysed with XRPD repeatedly as the sample dried. When visually dry it was analysed with TGA and was then allowed to absorb moisture from the ambient lab atmosphere before it was re-analysed with XRPD. The XRPD-data on the wet sample is shown in FIG. 9 and after TGA-analysis is given in FIG. 6 . Example 5 Preparation of Crystal Modification IV Via 2-PrOH-1 103.5 mg of elobixibat crystal modification IV was added to a Chromacol vessel and then 1.0 mL of 2-propanol and a stirring flea was added. The vessel was closed with a crimped cap, stirred for a day at 21° C. and was then sampled to a cut Silicon Zero Background Holder (ZBH) and analysed with XRPD repeatedly as the sample dried. When visually dry it was analysed with TGA and was then allowed to absorb moisture from the ambient lab atmosphere before it was re-analysed with XRPD. The XRPD-data on the wet sample is shown in FIG. 10 and after TGA-analysis is given in FIG. 6 . Example 6 Preparation of Crystal Modification IV Toluene (145.9 L) and 1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-t-phenyl-t-[N′-(t-butoxycarbonylmethyl)carbamoyl]methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine (7.295 kg) were charged to a 250-L GLR with stirring under nitrogen atmosphere, and the reaction mass was cooled to 3±2° C. Trifluoroacetic acid (21.89 L) was added slowly to the above reaction mass at 3±2° C. over a period of 2-3 h. The temperature of the reaction mass was raised to 25±5° C. and stirring was continued at this temperature for 21 h. The progress of the reaction was monitored by HPLC. The reaction mass was cooled to 3±2° C. and purified water (29.18 L) was added at 3±2° C. with stirring over a period of 30-40 min. The reaction mass was then warmed to 25±5° C. and stirred at this temperature for 15 min. The mass was allowed to settle for 15 min. and the layers were separated. The organic layer was washed with water (3×29.18 L) and then with a saturated brine solution (14.59 L). After each washing, the mass was allowed to settle for 15 min before the layer separation. The organic layer was filtered through a stainless steel Nutsche filter over a celite bed (3.0 kg of celite in 17.0 L of toluene) and the filtrate was collected. The celite bed was washed with toluene (14.59 L). The filtrates were combined and concentrated at a temperature below 40° C. under vacuum (500-600 mmHg) to about 7 to 14 L. The above mass was cooled to 25±5° C. and n-heptane (72.95 L) was added over a period of 10-15 min. The mixture was stirred at 25±5° C. for 2 h and then filtered. The filtered solids were washed with n-heptane (14.59 L) and suction dried for about 30 min. The above crude compound was dried in a vacuum tray dryer at 38±2° C. (500-600 mm Hg) for 10-12 h. Crude wt: 6.65 kg. Purity by HPLC: 98.5%. Absolute ethanol (29.18 L) was charged into a 250 L stainless steel reactor and heated to 43±2° C. The crude product from the previous step (6.65 kg) was added to the pre-heated ethanol and stirred at 43±3° C. for 15 min. The resulting solution was then cooled to 25±5° C. and stirred at this temperature for 1 h. During this time, the solution turned turbid. The mass was seeded with crystal modification IV (2.0 g). The mass was then cooled to 3±2° C. over a period of 2 h, and stirred at this temperature for 10 h. The precipitated solids were filtered and the solids were washed with chilled ethanol (1×3.65 L). The material was suction dried for 30 min. The material was then dried in a vacuum tray drier at 25±5° C. (500-600 mmHg) for 24 h and then at 63±2° C. (˜600 mmHg) for ˜50 h. The dried product was stored in a HDPE container. Yield 5.31 kg. The crystals absorbed water from the air. A water content of 2.70% was measured. The crystals were analyzed by XRPD and the results are shown in FIG. 1 . Example 7 Thermal Gravimetric Analysis of Crystal Modification IV A sample of crystal modification IV was analyzed with XRPD and the water content was checked with TGA. The weight loss for crystal modification IV was initially slow, but accelerated at about 50° C. and was finalized at about 80° C. A weight loss of 2.7% w/w was observed. The experiment could be repeated several times using the same sample, with rather similar results. Although water had been evaporated from the sample during the TGA analysis, the X-ray powder diffractograms taken before and after TGA analysis were similar (see FIG. 5 ). This indicates that the absorption of water takes place very rapidly. Furthermore, the experiment shows that the crystal modification is very stable, as the crystal shape is maintained upon evaporation and re-absorption of water. Example 8 Thermal Gravimetric Analysis of Crystal Modification I A sample of crystal modification I was analyzed with XRPD and the water content was checked with TGA. The weight loss occurred immediately at the onset of the analysis and was finalized at 50-60° C., indicating that the water in this compound is more loosely bound than in crystal modification IV. A weight loss of 0.99% w/w was observed. Example 9 DSC analysis of Crystal Modification IV Crystal modification IV exhibited an endothermic event in the temperature range 45 to 90° C. (onset 56° C.) with a peak at 78° C., with an enthalpy of 66.4 J/g. This event is due to the evaporation of water and corresponds to a water amount of about 2.9% w/w. A melting peak was observed in the temperature range 95 to 125° C. (onset 103° C.) with a peak at 110° C. Example 10 Cryo-DSC analysis of crystal modification I Crystal modification I exhibited an endothermic event in the temperature range 15 to 85° C. (onset 23° C.) with a peak at 56° C., with an enthalpy of 23.2 J/g. This event is due to the evaporation of water and corresponds to a water amount of about 1.03% w/w. A melting peak was observed in the temperature range 110 to 145° C. (onset 122° C.) with a peak at 131° C. Example 11 Dynamic Vapor Sorption Analysis of Crystal Modification IV A sample of crystal modification IV was weighed into the quartz scale pan of a Scientific Instruments Dynamic Vapor Sorption instrument. The sample was released of static electricity by moving a radioactive isotope over it and was then put into the instrument. The sample was dried by flushing dry nitrogen gas until the weight was constant and then two consecutive sorption-desorption cycles were run. Crystal modification IV absorbs approximately 2.45% water between 0 and 10% RH, and an additional 0.36 to 0.37% water between 10 and 60% RH. The resulting graph is shown in FIG. 11 . In FIG. 12 , a graph of the water uptake as a function of % RH is shown. The sample used in FIG. 12A was obtained from material produced on lab scale, whereas the sample used in FIG. 12B was obtained from GMP material produced on pilot plant scale. Example 12 Dynamic Vapor Sorption Analysis of Crystal Modification I A sample of crystal modification I was weighed into the quarts scale pan of a Scientific Instruments Dynamic Vapor Sorption instrument. The sample was released of static electricity by moving a radioactive isotope over it and was then put into the instrument. The sample was dried by flushing dry nitrogen gas until the weight was constant and then two consecutive sorption-desorption cycles were run. Crystal modification I absorbs approximately 0.66% water between 0 and 10% RH, and an additional 0.65 to 0.69% water between 10 and 60% RH. The resulting graph is shown in FIG. 13 . In FIG. 14 a graph of the water uptake as a function of % RH is shown. Example 13 Stability Test of Crystal Modification IV A batch of crystal modification IV was stored in a closed glass vial and kept at 20° C. and between 20 and 60% RH for 17 months. XRPD data indicated that the crystalline form was unchanged after 17 months. Example 14 Micrograph of Crystal Modification IV With a small spatula a small amount of crystal modification IV was put on an objective slide. A drop of Miglyol was added and the solid and liquid were thoroughly mixed with a needle, thus generating a slurry. A cover slip was put on top of the slurry and gently pushed down. The objective slide was then put on the rotating table of a Nikon Optiphot-2 polarized light microscope. The view of the slurry was well focused and the light was then adjusted to Köhler illumination. Then the second polarizer (the analyzer) was inserted perpendicular to the first one (the polarizer) so that the two polarizers were perfectly crossed. The analyzer was then slightly rotated so as to make the two polarizers slightly uncrossed. The specimen was carefully focused and then photographed through a 10 times objective giving FIG. 15 . Example 15 Micrograph of Crystal Modification I Following the procedure outlined in Example 14 but using crystal modification I instead, the micrograph shown in FIG. 16 was obtained. Example 16 Thermal Gravimetric Analysis of Crystal Modification EtOH-1 The solvent content of a sample of EtOH-1 was analyzed with TGA. A weight loss of approximately 6% w/w was observed, indicating that this crystal modification contains one mole of ethanol. Example 17 High-resolution X-Ray Powder Diffractogram of Elobixibat and Tablets Comprising Crystal Modification I or IV Measurement Method: X-ray powder diffraction in a high brilliance radiation facility ‘SPring-8 26B1’ Detector: R-AXIS V imaging plate detector (Manufacturer: RIGAKU) Radiation wavelength: 1.0000 Å Beam size: 100 μm×100 μm Distance between the sample and the detector: 420 mm Sample for measurement: enclosed in a glass capillary Vibrating angle: 80.0° Exposure time: 80 seconds Measurement range: 3-15° (2θ) Measurement temperature: 20° C. X-ray powder diffraction measurements by SPring-8 26B1 of crystal modification I (obtained in Example 1) and crystal modification IV were performed. The results are shown in FIG. 17 . Ingredients were mixed in the quantities shown in Table 1. The mixed powers were formed into tables with tabletting machinery (Manesty Betapress) under the condition (Weight: 3.15-3.25 g; Height: 3.85 mm) to obtain tablets comprising crystal modification I, tablets comprising crystal modification IV and placebo tablets, respectively. TABLE 1 Amount/unit (mg) Tablets Ingredients Tablets (cr. mod. I) (cr. mod. IV) Placebo Elobixibat (cr. mod. I) 15 — — Elobixibat (cr. mod. IV) — 15 — Microcrystalline cellulose 170.42 170.42 179.42 Mannitol 113.62 113.62 119.62 Hypromellose 5 cP 8.00 8.00 8.00 Croscarmellose sodium 8.00 8.00 8.00 Silica colloidal anhydrous 1.76 1.76 1.76 Magnesium stearate 3.20 3.20 3.20 Opadry II 16.0 16.0 16.0 Tablets comprising crystal modification I were ground to perform X-ray powder diffraction measurement with SPring-8 26B1. In order to identify the diffraction peaks additives other than crystal modification I, X-ray powder diffraction measurement of the placebo tablets was performed with SPring-8 26B1 in the same manner. The characteristic diffraction peaks of tablets comprising crystal modification I were found ( FIG. 18 ). The tablets were stored under the conditions of 40° C., 75% relative humidity for 8 weeks. Then, X-ray powder diffraction measurement of the stored tablets was performed with SPring-8 26B1 ( FIG. 19 ). No changes were observed in the peaks of the X-ray powder diffractogram, and the characteristic diffraction peaks of the tablets (crystal modification I) were found. X-ray powder diffraction measurement of crystal modification IV was performed with SPring-8 26B1 in a same manner as above. The characteristic diffraction peaks tablets comprising crystal modification IV were found ( FIG. 20 ). The tablets were stored under the conditions of 40° C., 75% relative humidity for 8 weeks, but no changes were observed in the peaks of the X-ray powder diffractogram; the characteristic diffraction peaks of tablets (crystal modification IV) were found ( FIG. 21 ). The above results demonstrate that crystal modification IV can exist stably in tablets.	The present invention relates to crystal modifications of N-{(2R)-2-[({[3,3-dibutyl-7-(methyl-thio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenylethanolyl}glycine (elobixibat), more specifically crystal modifications I, IV, MeOH-1, EtOH-1, 1-PrOH-1 and 2-PrOH-1. The invention also relates to a process for the preparation of these crystal modifications and to a pharmaceutical composition comprising crystal modification IV.	2
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority, pursuant to 35 U.S.C. § 119(e), to both U.S. Provisional Application No. 60/603,171 filed Aug. 20, 2004 and U.S. Provisional Application No. 60/565,316 filed Apr. 26, 2004. Both of these applications are incorporated by reference in their entirety. BACKGROUND OF INVENTION [0002] When drilling or completing wells in earth formations, various fluids typically are used in the well for a variety of reasons. For purposes of description of the background of the invention and of the invention itself, such fluids will be referred to as “well fluids.” Common uses for well fluids include: lubrication and cooling of drill bit cutting surfaces while drilling generally or drilling-in (i.e., drilling in a targeted petroleum bearing formation), transportation of “cuttings” (pieces of formation dislodged by the cutting action of the teeth on a drill bit) to the surface, controlling formation fluid pressure to prevent blowouts, maintaining well stability, suspending solids in the well, minimizing fluid loss into and stabilizing the formation through which the well is being drilled, fracturing the formation in the vicinity of the well, displacing the fluid within the well with another fluid, cleaning the well, testing the well, implacing a packer fluid, abandoning the well or preparing the well for abandonment, and otherwise treating the well or the formation. [0003] As stated above, one use of well fluids is the removal of rock particles (“cuttings”) from the formation being drilled. A problem arises in disposing these cuttings, particularly when the drilling fluid is oil-based or hydrocarbon-based. That is, the oil from the drilling fluid (as well as any oil from the formation) becomes associated with or adsorbed to the surfaces of the cuttings. The cuttings are then an environmentally hazardous material, making disposal a problem. [0004] A variety of methods have been proposed to remove adsorbed hydrocarbons from the cuttings. U.S. Pat. No. 5,968,370 discloses one such method which includes applying a treatment fluid to the contaminated cuttings. The treatment fluid includes water, a silicate, a nonionic surfactant, an anionic surfactant, a phosphate builder and a caustic compound. The treatment fluid is then contacted with, and preferably mixed thoroughly with, the contaminated cuttings for a time sufficient to remove the hydrocarbons from at least some of the solid particles. The treatment fluid causes the hydrocarbons to be desorbed and otherwise disassociated from the solid particles. [0005] Furthermore, the hydrocarbons then form a separate homogenous layer from the treatment fluid and any aqueous component. The hydrocarbons are then separated from the treatment fluid and from the solid particles in a separation step, e.g., by skimming. The hydrocarbons are then recovered, and the treatment fluid is recycled by applying the treatment fluid to additional contaminated sludge. The solvent must be processed separately. [0006] Some prior art systems use low-temperature thermal desorption as a means for removing hydrocarbons from extracted soils. Generally speaking, low-temperature thermal desorption (LTTD) is an ex-situ remedial technology that uses heat to physically separate hydrocarbons from excavated soils. Thermal desorbers are designed to heat soils to temperatures sufficient to cause hydrocarbons to volatilize and desorb (physically separate) from the soil. Typically, in prior art systems, some pre- and post-processing of the excavated soil is required when using LTTD. In particular, excavated soils are first screened to remove large cuttings (e.g., cuttings that are greater than 2 inches in diameter). These cuttings may be sized (i.e., crushed or shredded) and then introduced back into a feed material. After leaving the desorber, soils are cooled, re-moistened, and stabilized (as necessary) to prepare them for disposal/reuse. [0007] U.S. Pat. No. 5,127,343 (the '343 patent) discloses one prior art apparatus for the low-temperature thermal desorption of hydrocarbons. FIG. 1 from the '343 patent reveals that the apparatus consists of three main parts: a soil treating vessel, a bank of heaters, and a vacuum and gas discharge system. The soil treating vessel is a rectangularly shaped receptacle. The bottom wall of the soil treating vessel has a plurality of vacuum chambers, and each vacuum chamber has an elongated vacuum tube positioned inside. The vacuum tube is surrounded by pea gravel, which traps dirt particles and prevents them from entering a vacuum pump attached to the vacuum tube. [0008] The bank of heaters has a plurality of downwardly directed infrared heaters, which are closely spaced to thoroughly heat the entire surface of soil when the heaters are on. The apparatus functions by heating the soil both radiantly and convectionly, and a vacuum is then pulled through tubes at a point furthest away from the heaters. This vacuum both draws the convection heat (formed by the excitation of the molecules from the infrared radiation) throughout the soil and reduces the vapor pressure within the treatment chamber. Lowering the vapor pressure decreases the boiling point of the hydrocarbons, causing the hydrocarbons to volatize at much lower temperatures than normal. The vacuum then removes the vapors and exhausts them through an exhaust stack, which may include a condenser or a catalytic converter. [0009] In light of the needs to maximize heat transfer to a contaminated substrate using temperatures below combustion temperatures, U.S. Pat. No. 6,399,851 discloses a thermal phase separation unit that heats a contaminated substrate to a temperature effective to volatize contaminants in the contaminated substrate but below combustion temperatures. As shown in FIGS. 3 and 5 of U.S. Pat. No. 6,399,851, the thermal phase separation unit includes a suspended air-tight extraction, or processing, chamber having two troughs arranged in a “kidney-shaped” configuration and equipped with rotating augers that move the substrate through the extraction chamber as the substrate is indirectly heated by a means for heating the extraction chamber. [0010] In addition to the applications described above, those of ordinary skill in the art will appreciate that recovery of adsorbed hydrocarbons is an important application for a number of industries. For example, a hammermill process is often used to recover hydrocarbons from a solid. One recurring problem, however, is that the recovered hydrocarbons, whether they are received by either of the methods described above or whether by another method, can become degraded, either through the recovery process itself, or by the further use of the recovered hydrocarbons. [0011] This degradation may result in pungent odors, decreased performance, discoloration, and/or other factors which will be appreciated by those having ordinary skill in the art. What is needed, therefore, are methods and apparatuses for improving the properties of recovered hydrocarbons. SUMMARY OF INVENTION [0012] In one aspect, the present invention relates to a method of treating a hydrocarbon fluid that includes contacting the hydrocarbon fluid with an effective amount of ozone. [0013] In another aspect, the present invention relates to a method for separating contaminants from a contaminated material that includes the steps of supplying the contaminated material to a processing chamber, moving the contaminated material through the processing chamber, heating the contaminated material by externally heating the processing chamber so as to volatilize the contaminants in the contaminated material, removing vapor resulting from the heating, wherein the vapor comprises the volatilized contaminants, collecting, condensing, and recovering the volatilized contaminants, and contacting the volatilized contaminants with an effective amount of ozone. [0014] In yet another aspect, the present invention relates to a system for separating contaminants from a material that includes a processing chamber, a heat source connected to the processing chamber adapted to vaporize hydrocarbons and other contaminants disposed on the material, a condenser operatively connected to an outlet of the process chamber and adapted to condense the vaporized hydrocarbons and other contaminants, and an ozone source operatively connected to the condenser. [0015] Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS [0016] FIG. 1 a is a GC/MS trace of an untreated sample of hydrocarbon fluid; [0017] FIG. 1 b is a GC/MS trace of a sample of hydrocarbon fluid treated in accordance with one embodiment of the present invention; [0018] FIG. 2 a is an extracted ion scan of an untreated sample of hydrocarbon fluid; and [0019] FIG. 2 b is an extracted ion scan of a sample of hydrocarbon fluid treated in accordance with one embodiment of the present invention. [0020] FIG. 3 shows an apparatus for ozone treatment in accordance with one embodiment of the invention. DETAILED DESCRIPTION [0021] In one or more aspects, the present invention relates to methods and apparatuses for treating hydrocarbons. In particular, aspects of the present invention relate to methods and apparatuses for treating hydrocarbons that have been recovered from solid materials. [0022] As noted above, a number of prior art methodologies for recovering adsorbed hydrocarbons from “cuttings” (i.e., rock removed from an earth formation) are currently used by hydrocarbon producers. While the present invention is not limited to this industry, the embodiments described below discuss the process in that context, for ease of explanation. In general, embodiments of the present invention may be applied to any “cracked” hydrocarbon fluid. A “cracked” hydrocarbon fluid is one where at least some of the “higher” alkanes present in a fluid have been converted into “smaller” alkanes and alkenes. [0023] A typical prior art process for hydrocarbon recovery, as described above, involves indirectly heating a material having absorbed hydrocarbons causing the hydrocarbons to volatilize. The volatized hydrocarbon vapors are then extracted, cooled and condensed. As a result of the heating process, even at low temperatures, a portion of the recovered hydrocarbon fluid may be degraded. As used herein, the term degraded simply means that at least one property of the hydrocarbon fluid is worse than a “pure” sample. For example, a degraded fluid may be discolored, may have a pungent odor, or may have increased viscosity. “Recovered” hydrocarbons, as used herein, relate to hydrocarbons which have been volatized off of a solid substrate and condensed through any known method. [0024] In a first embodiment, the present invention involves contacting a cracked hydrocarbon fluid with a stream of ozone. Ozone is known as an oxidizing agent, and previous studies have shown that ozone does not react with saturated compounds such as alkanes and saturated fatty acids. It is also known that ozone will react with unsaturated compounds such as alkenes, unsaturated fatty acids, unsaturated esters and unsaturated surfactants. The present inventors have discovered that by passing ozone through cracked hydrocarbons, improved hydrocarbon fluids may result. In particular, the present inventors have discovered that a reduction in odor and an improved coloration may occur. Reducing odor is of significant concern because of the increased regulation of pollution in hydrocarbon production. [0025] Embodiments of the present invention involve contacting a hydrocarbon fluid with an effective amount of ozone. An “effective amount,” as used herein refers to an amount sufficient to improve a desired property (such as odor or color) in a hydrocarbon fluid. One of ordinary skill in the art would appreciate that the effective amount is a function of the concentration of the contaminants and the volume of the hydrocarbons to be treated. [0026] Without being bound to any particular mechanism, the present inventors believe that the present invention operates through a chemical reaction known as ozonolysis. The reaction mechanism for a typical ozonolysis reaction involving an alkene is shown below: [0027] Thus, in the reaction, an ozone molecule (O 3 ) reacts with a carbon-carbon double bond to form an intermediate product known as ozonide. Hydrolysis of the ozonide results in the formation of carbonyl products (e.g., aldehydes and ketones). It is important to note that ozonide is an unstable, explosive compound and, therefore, care should be taken to avoid the accumulation of large deposits of ozonide. [0028] The efficacy of ozone as an agent to improve at least one property of a hydrocarbon fluid was investigated. In this embodiment, recovered hydrocarbons were used. One suitable source for the recovered hydrocarbons is described in U.S. patent application Ser. No. 10/412,720, which is assigned to the assignee of the present invention. That application is incorporated by reference in its entirety. [0029] Another suitable source of recovered hydrocarbons is described in U.S. Pat. No. 6,658,757, which is assigned to the assignee of the present invention. That patent is incorporated by reference in its entirety. These two methods of obtaining recovered hydrocarbons are merely examples, and the scope of the present invention is not intended to be limited by the source of the hydrocarbon fluid to be treated. [0030] In one embodiment, a 500 ml sample of recovered hydrocarbon was placed in a cylinder. Ozone was bubbled through the cylinder at a rate of 8 g per day. Commercial ozone generators are available from a variety of vendors. For this particular embodiment, a Prozone PZ2-1 ozone generator sold by Prozone International Inc. (Hunstville, Ala.) was used. The top of the cylinder remained open to the air, in order to avoid a build up of ozonide. However, a vacuum blower could also be used to continuously purge the ozonide. In this embodiment, it was discovered that by contacting the ozone with the recovered hydrocarbons for 48 hours, substantial improvement in the color and the odor of the recovered hydrocarbons was seen. As a baseline, a similarly sized sample of recovered hydrocarbon had air bubbled through it for the same period of time. [0031] After 48 hours, the two samples were analyzed by GC/MS. FIGS. 1 a and 1 b show the results. FIG. 1 a is a GC/MS scan of the recovered hydrocarbon that had air bubbled through it, while FIG. 1 b is a GC/MS scan of the recovered hydrocarbon that was treated with ozone. Inspection of the scans reveals that the traces are very similar. This was expected as these samples comprise mostly saturated hydrocarbons which do not react with ozone. [0032] FIGS. 2 a and 2 b which are extracted ion scans (i.e., second MS analysis) of the two samples, however, show that ozonolysis has an effect on the recovered hydrocarbons. In FIG. 2 a (the untreated sample), large amounts of xylene (panel 1 ) and benzene derivatives (panel 2 ) are present. In FIG. 2 b (the treated sample), however, these peaks are not present, indicating that the ozone has selectively attacked the carbon-carbon double bonds present in these molecules. In contrast, panels 3 of FIG. 2 a and FIG. 2 b show that the saturated hydrocarbon C 11 H 24 , remains unchanged after ozonolysis. The reduction of the amount of unsaturated hydrocarbons leads to improved performance, odor, and color in the recovered hydrocarbon fluid. [0033] To further understand the chemistry behind the reaction, the untreated fluid (i.e., recovered hydrocarbon contacted only with air) and the treated fluid were tested and analyzed on a GC/MS for paraffins, iso-paraffins, aromatics, napthenics, olefins, aldehydes, ketones, and acids (the latter three collectively called “other compounds”). The results are summarized in the table below: TABLE 1 GC/MS data for treated vs. untreated fluid Compound Untreated Fluid Treated Fluid Paraffin 20.69% 21.71% Iso-paraffin 27.56% 32.14% Aromatics 13.27% 10.67% Naphthenics 23.48% 16.57% Olefins 2.97% 3.69% Other compounds 11.94% 15.22% [0034] The above table illustrates that the unsaturated aromatics and naphthenics are attacked by ozone, reducing their concentration in the treated fluid. These samples also contain low amounts of olefins. While the analysis does not show a reduction in olefin concentration, this is most likely due to the error inherent in the analysis. [0035] In order to increase the reactivity of the ozone, a number of changes can be incorporated into the process. For example, the reaction vessel may be slightly pressurized in order to increase the solubility of the ozone in the hydrocarbon fluid. 7-8 psi is a preferred range, but those of ordinary skill will recognize that depending on the application, higher pressures may be used. Further, because the ozonolysis reaction is believed to be driven by the surface area of the ozone bubbles, ultrasonic systems may be used to decrease the size of individual ozone bubbles, leading to increased contact, which, in turn, increases the rate of the ozonolysis reaction. In addition, those having ordinary skill in the art will appreciate that another way to get improved contact is by using long, narrow columns of fluid, and passing the ozone through such a column. [0036] The removal of organochlorine substances or microorganisms may also be accomplished by a cavitation phenomenon using ultrasound and injections of ozone, peroxides, and/or catalysts, such as within JP-900401407 (Ina Shokuhin Kogyo), JP-920035473 (Kubota Corp.), JP-920035472 (Kubota Corp.) and JP-920035896 (Kubota Corp.). Further the use of ultrasound with or without ozone is reported for the treatment of sewage sludge. Thus, it is contemplated that the combination of ozone and ultrasound (either low frequency or high frequency) may provide additional benefits to the treatment process described herein. For example, a tank with a sparger for ozone and a source for ultrasound may provide enhanced processing of the recovered oil. Alternatively, a continuous flow process (either concurrent flow or counter flow) in which ultrasound is introduced is contemplated as being within the scope of the present invention. [0037] Depending on the particular amount of hydrocarbon liquid to be treated, a selected amount of ozone per day may be used. Further, the methods and apparatuses of the present invention may be used as a batch process, whereby barrels of hydrocarbon fluids are transported to a different location for ozone treatment, or they may be used in a continuous recovery process, whereby the ozone is added during the recovery process. Those having ordinary skill will recognize that continuous recovery may be used in either the process described in U.S. patent application Ser. No. 10/412,720 or U.S. Pat. No. 6,658,757. [0038] FIG. 3 illustrates an apparatus in accordance with an embodiment of the present invention. FIG. 3 shows an embodiment of an apparatus 90 for improving the properties of recovered hydrocarbons from wellbore cuttings 100 . In the embodiment shown in FIG. 3 , cuttings 100 contaminated with, for example, oil-based drilling fluid and/or hydrocarbons from the wellbore (not shown) are transported to the surface by a flow of drilling fluid returning from the drilled wellbore (not shown). The contaminated cuttings 100 are deposited on a process pan 102 . In some embodiments, the cuttings 100 may be transported to the process pan 102 through pipes (not shown) along with the returned drilling fluid. In other embodiments, the cuttings 100 may be, for example, processed with conveying screws or belts (not shown) before being deposited in the process pan 102 . The process pan 102 is then moved into a process chamber 103 via, for example, a fork lift (not shown separately in FIG. 3 ). For example, in some embodiments of the invention, the process pan 102 may be rolled in and out of the process chamber 103 on a series of rollers. [0039] In other embodiments, the process pan 102 may be moved vertically in and out of the process chamber 103 with, for example, hydraulic cylinders. Accordingly, the mechanism by which the process pan 102 is moved relative to the process chamber 103 is not intended to be limiting. Moreover, some embodiments of the apparatus 90 may comprise a plurality of process chambers 103 and/or a plurality of process pans 102 . Other embodiments, such as the embodiment shown in FIG. 3 , comprise a single process pan 102 /process chamber 103 system. Furthermore, the number of process pans 102 and process chambers 103 need not be the same. [0040] The process chamber 103 includes, in some embodiments, a hydraulically activated hood (not shown) that is adapted to open and close over the process chamber 103 while permitting the removal or insertion of the process pan 102 . After the process pan 102 has been inserted into the process chamber 103 , the hydraulically activated hood (not shown) may be closed so as to “seal” the process chamber 103 and form an enclosed processing environment. The hood (not shown) may then be opened so that the process pan 102 may be removed. [0041] After the process pan 102 has been positioned in the process chamber 103 , heated air, which has been heated by a heating unit 112 (which may be, for example, a propane burner, electric heater, or similar heating device), is forced through the contaminated cuttings 100 so as to vaporize hydrocarbons and other volatile substances associated or adsorbed thereto. The heated air enters the process chamber 103 through, for example, an inlet duct 120 , pipe, or similar structure known in the art. The heated air, which may be heated to, for example, approximately 400° F., is forced through the process pan 102 by, for example, a blower (not shown). [0042] However, a blower may not be necessary in some embodiments if the pressure in the air circulation system is maintained at a selected level sufficient to provide forced circulation of the heated air through the contaminated cuttings 100 . As the heated air is forced through the process pan 102 , the air volatilizes the hydrocarbon and other volatile components that are associated with the cuttings 100 . The hydrocarbon rich air then exits the bottom of the process chamber 103 through, for example, an outlet duct 122 and passes through a heat recovery unit 108 . The heat recovery unit 108 recaptures some of the heat from the hydrocarbon rich air and, for example, uses the recaptured heat to heat additional hydrocarbon free air that may then be recirculated through the process chamber 103 through the inlet duct 120 . Some hydrocarbons, water, and other contaminants from the contaminated cuttings 100 may be directly liquefied as a result of the forced-air process. These liquefied hydrocarbons, water, and/or other contaminants flow out of the process chamber 103 and through a process chamber outlet line 106 . [0043] After passing through the heat recovery unit 108 , the hydrocarbon rich air is drawn through a series of filters 124 that are adapted to remove particulate matter from the air. The hydrocarbon rich air is then passed through an inlet 126 of a first condenser 110 . Note that the inlet 126 of the first condenser 110 is typically operated under a vacuum to control the flow of hydrocarbon rich air. The vacuum at the inlet 126 may be produced, for example, by a vacuum pump (not shown separately in FIG. 3 ). [0044] The first condenser 110 further comprises cooling coils (not shown separately in FIG. 3 ) adapted to condense the volatilized hydrocarbons (and, for example, an water vapor and/or other contaminants) in the hydrocarbon rich air into a liquid form. The liquefied hydrocarbons and contaminants are then removed through, for example, a condenser outlet 128 that conveys the liquefied hydrocarbons and contaminants to an oil/water separator 116 . The apparatus 90 may also comprise, for example, pumps (not shown) that may assist the flow of liquefied hydrocarbons and contaminants from the condenser outlet 128 to the oil/water separator 116 . [0045] After passing through the first condenser 110 , the cooled air then flows through a second series of filters and cooling coils 130 and into a second condenser 111 that operates at or near atmospheric pressure. The second condenser 111 boosts the pressure of the ambient airflow, and any additional condensate is removed from the process stream through an outlet 132 that transports the additional condensate to the oil/water separator 116 . [0046] An ozone generator 142 is connected to the oil/water separator 116 . The ozone generator 142 is arranged to provide a selected amount of ozone (usually selected in grams per day) into the oil/water separator 116 . In a preferred embodiment, the oil/water separator 116 comprises long, narrow columns, so that the contact area of the ozone is increased. Further, in some embodiments, an ultrasonic system (not separately shown) is coupled to the oil/water separator 116 to increase the ozone contact area. Further, in certain other embodiments, the oil/water separator 116 may be placed under pressure to increase the amount of ozone that can dissolve in the system. The oil/water separator 116 may further comprise a vent 144 to allow built up gases to evacuate the system, or may be attached to a vacuum blower, for example. Those having ordinary skill in the art will recognize that although the above embodiment describes a multi-condenser system, some embodiments contemplate the use of only a single condenser. Those having ordinary skill will appreciate that the ozone generator is operatively coupled to a recovered hydrocarbon fluid, and that the operative coupling may take place in a variety of ways. [0047] In an alternative embodiment, contaminated material (i.e., solids containing adsorbed hydrocarbons) may first be screened to remove stones, rocks, and other debris, and then deposited into a feed hopper. The contaminated material may be fed directly into a feed hopper, or fed from a feed hopper into a lump breaker by a horizontal conveyor belt. From the lump breaker, the contaminated material is discharged onto an inclined conveyor belt for delivery to a feed hopper that directs the contaminated material to rotary paddle airlock valves. [0048] Upon passing through the airlock valves, the contaminated substrate drops into an extraction chamber (also referred to as “processing chamber”) and is moved through the extraction chamber by an auger screw. As the contaminated material moves though the extraction chamber, the contaminated material is indirectly heated by a combustion system that supplies heat to the extraction chamber from burners located externally and underneath the extraction chamber. The contaminated substrate remains physically separated from the combustion system by the extraction chamber's steel shell. [0049] An enclosure referred to as “firebox” houses the extraction chamber and burners of the combustion system. As eluded to above, the firebox derives its heat by the combustion of commercially available fuels. The heat can be varied so that the temperature of the contaminated substrate is elevated to the point that the contaminants in the contaminated material are volatilized. [0050] The treated substrate is then passed through a rotary airlock valve at the end of the extraction chamber and become available for rewetting and reintroduction to the environment. The volatilized contaminants are removed from the extraction chamber and directed to a vapor handling system. [0051] The volatilized water and contaminants generated in the extraction chamber are subject to a vapor/gas condensation and clean-up system for the purpose of collection and recovery of the contaminants in liquid form. An ozone generator may then be operatively connected to the contaminants, which comprise hydrocarbon fluids, in order to treat the fluid. The vapor/gas condensation and clean-up system preferably includes a plurality of steps. First, the hot volatilized vapors/gases from the extraction chamber are cooled through direct contact water sprays in a quench header and the water required by the quenching process is provided by spray nozzles spaced at regular intervals along the quench header. [0052] Second, the vapor/gas stream is then directed through one or more knock-out pots to remove residual particulate matter and large water droplets. Third, the vapor stream is subjected to a water impinger to further remove finer particulate matter and smaller water droplets. Fourth, the relatively dry vapor/gas stream of non-condensable gases is subject to one or more mist eliminators for aerosol removal. Fifth, the vapor/gas stream may be passed through a high efficiency air filtration system to remove any submicron mists or particles still remaining in the vapor/gas stream. [0053] Glass media may be used in the filter system to filter material down as a microlite, and, as such, the filters remove liquid mist down to a 0.05 micron level. Finally, the vapor/gas stream may be subjected to a final polishing in a series of carbon absorption beds and subsequently vented to the atmosphere or returned to the burners of the combustion system. The ozone generator may be attached at a number of positions in the above embodiments, but should preferably be attached in a fashion to avoid placing significant heat on the ozonide formed during the ozonolysis reaction, to reduce the chance of an explosion. [0054] In addition, those having ordinary skill in the art will recognize that the rate (i.e., the amount of ozone per day) may be varied, depending on a particular application in order to optimize treatment of recovered hydrocarbon fluids. Further, the reaction time (i.e., the length of time that the hydrocarbon fluids are subjected to ozone) may vary depending on the particular application. Still further, the extent of reaction (i.e., the amount of double bonds broken) may vary, depending on the amount of degradation that has occurred, and the desired end properties of the hydrocarbon fluid. Advantageously, embodiments of the present invention provide an improvement in at least one property of a “cracked” hydrocarbon fluid. [0055] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.	A method of treating a hydrocarbon fluid that includes contacting the hydrocarbon fluid with an effective amount of ozone. A method for separating contaminants from a contaminated material includes supplying the contaminated material to a processing chamber, moving the contaminated material through the processing chamber, heating the contaminated material by externally heating the processing chamber so as to volatilize the contaminants in the contaminated material, removing vapor resulting from the heating, wherein the vapor comprises the volatilized contaminants, collecting, condensing, and recovering the volatilized contaminants, and contacting the volatilized contaminants with an effective amount of ozone.	2
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to a new, simple, and easy process for preparing cephalosporin antibiotics including ceftazidime, cefixime, and the like. More particularly, the present invention relates to a process for the preparation of cephalosporin antibiotics of the following formula (I), in which a 7-amino cephalosporanic acid derivative of the following formula (III) is acylated by reaction with a new crystalline aminothiazole derivative of the following formula (II) in a solvent: wherein R 1 and R 2 are the same or different and independently represent H, an alkyl group of 1 to 4 carbon atoms, or a cycloalkyl group of 3 to 5 carbon atoms, etc., R 4 represents acetoxymethyl, pyridiniummethyl, or vinyl, COOM is COO − when R 4 is pyridiniummethyl and COOH otherwise, and X represents chlorine or bromine. Moreover, the acid in the acid addition salt as shown in the formula (II) represents an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, or perchloric acid, etc., or an organic acid, such as formic acid, acetic acid, trifluoroacetic acid, propionic acid, methanesulfonic acid, or benzenesulfonic acid, etc. 2. Description of the Prior Art Processes for the preparation of cephalosporin antibiotics of the above formula (I), including ceftazidime and cefixime, were disclosed in several literatures and patents, for example, U.S. Pat. No. 4,258,041; Austrian Patent Publication Nos. 86-2427 and 86-2428 ; J. of Antibiotics , Vol.38, pp. 1738, 1985; and Korean Patent Publication Nos. 84-1827, 84-1987, 84-1988, 84-1989, 84-1990, 87-1807, and 93-7810. In the above prior processes, an amino group of a 3-cephem compound represented by the following formula (I-1) is acylated by reaction with a 2-aminothiazol carboxylic acid of the following formula (I-2) or a salt or reactive derivative thereof to produce the cephalosporin derivative of the formula where R 1 , R 2 , and R 4 have the same meanings as described above, R 3 is a carboxy protecting group, R a is hydrogen or an amino protecting group, R b is hydrogen or a carboxy protecting group, such as diphenylmethyl or p-nitrobenzene. U.S. Pat. No. 4,258,041, and Korean Patent Publication No. 84-1827, etc. describe processes employing acid chloride of the organic acid (I-2) in the acylation reaction with the 7-amino cephalosporin derivative of the formula (I-1). According to these processes, the organic acid (I-2) is conventionally protected on an amino group of its thiazole ring, and then converted to its acid chloride with thionyl chloride, phosphorus oxychloride, or phosphorus pentachloride, etc. Thereafter, the resulting acid chloride of the organic acid (I-2) is reacted with the 7-amino cephalosporanic acid derivative, followed by removing the protecting group on the amino group of the thiazole ring. However, these processes have disadvantages in that they are carried out under strict reaction conditions, and further require a step of protecting the amino group of the thiazole ring and a step of removing the protecting group on the amino group. In addition, another drawback with these processes is that the aminothiazole compound activated with unstable acid chloride is acylated as such without being subjected to an isolation step, such that by-products are significantly produced during the acylation reaction owing to the unstable acid chloride. Austrian Patent Publication Nos. 86-2427 and 86-2428, and WO No. 98-31685, etc. disclose processes in which a reactive ester of the organic acid (I-2) is prepared and acylated. In this acylation, the reactive ester of the organic acid (I-2) may be reacted with the 7-aminocephalosporin derivative without the protecting group on the amino group of its thiazole ring. However, it is necessary for these processes to remove a protecting group on a carboxy group of the aminothiazole compound (I-2) after the acylation reaction, in order to give the final desired compound. In addition, there are also known other processes employing a reactive amide or a mixed acid anhydride, but they have drawbacks similar to those in the above processes. Therefore, in the case of carrying out the acylation reaction using the reactive derivative (e.g., the acid chloride) as described above, the amino and carboxyl groups of the compound of the formula (I-2) must be protected with R a other hand, in the case of using the reactive ester, the preparation of the reactive ester must be carried out in a state where the amino group is not protected, but the carboxyl group is protected with R 3 . As a result, all the processes according to the prior art have a drawback in that the deprotection must be carried out after the acylation reaction. SUMMARY OF THE INVENTION We have discovered that, when an aminothiazole compound represented by the following formula II was acylated by reaction with a 7-amino cephalosporanic acid derivative represented by the following formula (III) in a solvent as indicated in the following reaction scheme, a desired compound could be directly obtained in a high yield in a simple and easy way without a need of the deprotection after the acylation reaction, whereby we have perfected the present invention based on this discovery: wherein R 1 , R 2 , R 4 , and the acid addition salt have the same meaning as defined above. It is therefore an object of the present invention to provide a process for preparing cephalosporin antibiotics including ceftazidime and cefixime, etc., using a new aminothiazole compound represented by the formula (II). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing and other objects, features and advantages of the invention will be apparent to those skilled in the art to which the present invention relates from reading the following specification. The aminothiazole compound of the formula (II) used as the starting material in the practice of the present invention is a new material and a reactive derivative in the form of a crystalline acid chloride. Thus, this is more stable and can be stored over a lengthy period of time at a low temperature and room temperature, as compared with the conventional acid chloride. Moreover, the process of the present invention produces little or no by-products in the acylation reaction of the 7-aminocephalosporin derivative with the compound of the formula (II), and is also relatively short in reaction time. Additionally, the process of the present invention employing this compound of the formula (II) does not require the removal of the protecting group after the acylation, and allows the desired compound to be directly obtained after the acylation. As a result, the process of the present invention makes the acylation reaction more economical and also simple and easy. The new aminothiazole derivative of the formula (II) is described in detail in Korean Patent Application No.2000-11127 (Filing date: Mar. 6 2000; Name of Applicant: HANMI FINE CHEMICALS, CO., LTD; and Title: New thiazole compounds and a process thereof), the disclosure of which is incorporated herein by reference. Moreover, among the derivatives of the formula (III), a 3-vinyl-7-aminocephalosporanic acid and a 3-pyridiniummethyl-7-aminocephalosporanic acid mentioned herein are known compounds and described in detail in several literatures, for example, U.S. Pat. No. 4,423,213, Korean Patent No. 127,113, and British Patent No. 2,052,490, the disclosure of which is incorporated herein by reference. In the acylation reaction according to the present invention, the compound of the formula (II) is used in the amount of 1.0 to 2.0 equivalents, and preferably 1.2 to 1.4 equivalents, relative to the compound of the formula (III). The solvent which can be used in the practice of the present invention includes, for example, dichloromethane, dichloroethane, chloroform, acetonitrile, tetrahydrofuran, N,N-dimethylacetamide, N,N-dimethylformamide, methanol, ethanol, or a combination thereof. However, a solution adjuvant, such as N,O-bistrimethylsilylacetamide, trimethylchlorosilane, or trimethyliodosilane, etc., may also be used in combination with the solvent in the present invention depending on the kind of the 7-cephalosporin derivative. The solvent is used in the amount of 5 ml to 30 ml, and preferably 10 ml to 15 ml, relative to 1 g of the compound of the formula (II). The acylation reaction according to the present invention is preferably carried out at a temperature of −10° C. to 30° C. The acylation reaction of the present invention is generally carried out without the use of a base, although an organic or inorganic base may also be used depending on the 7-aminocephalosporin derivative. If used, the base is used in the amount of 1.0 to 3.0 equivalents. Examples of the organic base which can be used in the present invention include tri-(n-butyl)amine, diisopropylethylamine, pyridine, dicyclohexylamine, and the like. Moreover, the acylation reaction may also be carried out in a mixed solution of a basic aqueous solution and the organic solvent, with the basic aqueous solution being preferably an aqueous solution of sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, or sodium hydroxide, etc. In this acylation reaction, water and the organic solvent are preferably used in the volume of 10 times to 20 times relative to the compound of the formula (II), with the volume ratio of water to the organic solvent being 1/4 to 1/10. As described above, the process for the preparation of the cephalosporin derivative is characterized in that the compound of the formula (III) is reacted with the new thiazole compound of the formula (II), as the reactive organic acid derivative, to give the cephalosporin derivative of the formula (I). Such a process does not require the deprotection step and is reduced in production step, as compared with the processes according to the prior art. Furthermore, as the reactive acid derivative used in the process of the present invention is the acid chloride of the stable crystalline form, the acylation reaction with the compound of the formula (II) can be completed clean in a quantitative view with little or no production of by-products. In addition, the compound of the formula (II) can be stored in the form of acid chloride and is thus easy to use. As a result, the present invention provides the more inexpensive and new acylation process for the preparation of the cephalosporin derivatives having the compound of the formula (II) at a 7-position. The following examples are for illustration purposes only and in no way limit the scope of this invention. EXAMPLE 1 Preparation of 7-{2-(2-aminothiazol-4-yl)-2-(Z)-(2-carboxyprop-2-oxyimino)acetamido}-3-(1-pyridiniummethyl) -ceph-3-em-4-carboxylate dihydrochloride(ceftazidime dihydrochloride) To 100 ml of acetonitrile which was cooled down to 0 to 5° C., 10 g of 7-amino-3-(1-pyridiniummethyl)-ceph-3-em-carboxylate dihydrochloride was added, and 5 ml of N,O-bistrimethylsilylacetamide was then slowly added dropwise over 30 minutes. After adding 9.4 g of (Z)-(2-carboxyprop-2-oxyimino)-2-aminothiazole-4-yl)-acetylchloride monohydrochloride, the resulting solution was stirred for 30 minutes, and 20 ml of 35% concentrated hydrochloric acid was then added to the stirred solution, followed by adding 50 ml of diethylether. Next, the solution was stirred for 10 minutes, and an aqueous layer was then separated and collected. After 100 ml of acetone was added to the aqueous layer and the mixture was stirred at room temperature for 5 to 6 hours, the deposited crystal was filtered. The filtered crystal was washed with 50 ml of isopropyl alcohol, and then with 20 ml of acetone, and dried, thereby giving 12.4 g (84% yield) of the title compound as a white solid. 1 NHR :(d, DMSO-d 6 ):9.6(d, 1H, —CONH—), 9.0(d, 2H, pyridinium proton), 8.6(t, 2H, pyridinium proton), 8.2(t, 2H, pyridinium proton), 6.8(s, 1H, aminothiazole proton), 5.9(dd, 1H, C 7 —H), 5.6(ABq, 2H, —CH 2 —), 5.2(d, 1H, C 6 —H), 3.5(ABq, 2H, C 2 —H), 1.4(s, 6H, —C(CH 3 ) 2 ) EXAMPLE 2 Preparation of 7-{2-(2-aminothiazole-4-yl)-2-(Z)-(2-carboxyprop-2-oxyimino)acetamido}-3-(1-pyridiniummeth yl)-ceph-3-em-4-carboxylate pentahydrate(ceftazidime penta hydrate) To 100 ml of dichloromethane, 10 g of 7-amino-3-(1-pyridiniummethyl)-ceph-3-em-4-carboxylate hydroiodide was added, and 4 ml of triethylamine was then added dropwise at a temperature of 0 to 10° C. to ensure the dissolution of the hydroiodide. To which, (Z)-(2-carboxyprop-2-oxyimino)-2-(2-aminothiazole-4-yl)-acetylchloride monohydrochloride was added three or four times for 30 minutes in such a fashion that the totally added amount thereof corresponds to 9.4 g. The resulting mixture was then stirred at a temperature of 0 to 10° C. for 30 minutes. The stirred solution was added with 50 ml of water to be separated into two layers. Next, an aqueous layer was collected, to which 2 g of activated carbon was added. The solution was stirred for 30 minutes, and the stirred solution was filtered by a siliceous earth to remove the activated carbon. The resulting solution was adjusted to pH 3.8 with a 2N-hydrochloric acid solution, and left to stand at 5° C. for 12 hours. The resulting crystal was filtered, and washed with ice-water and acetone, in sequence, and then dried, thereby giving 11.8 g (80% yield) of the title compound as a white solid. 1 NHR :(d, DMSO-d 6 ): 9.5(d, 1H, —CONH—), 9.4(d, 2H, pyridinium proton), 8.6(t, 2H, pyridinium proton), 8.2(t, 2H, pyridinium proton), 7.3(s, 2H, —NH 2 ), 6.7(s, 1H, amino-thiazole proton), 5.7(dd, 1H, C 7 —H), 5.5(ABq, 2H, —CH 2 —), 5.1(d, 1H, C 6 —H), 3.3(ABq, 2H, C 2 —H), 1.4(s, 6H, —C(CH 3 ) 2 ) EXAMPLE 3 Preparation of 7-[2-(2-aminothiazole-4-yl)-2-(Z)-(carboxymethoxyimino)acetamido]-3-vinyl-3-cephem-4-carboxylic acid trihydrate (cefixime) 10 g of 7-amino-3-vinyl-3-cephem-4-carboxylic acid was suspended in 100 ml of dichloromethane, and to which, 10 ml of N,O-bistrimethylsilylacetamide was added dropwise to ensure the dissolution of the carboxylic acid. At a temperature of 20 to 30° C., 14 g of (Z)-2-(2-carboxymethoxyimino)-2-(2-aminothiazole-4-yl)acetylchloride monohydrochloride was added in parts and the resulting solution was stirred. After this, 50 ml of a saturated aqueous solution of sodium hydrogen carbonate and 100 ml of isopropylether were sequentially added, and the resulting solution was stirred for 10 minutes and separated into two layers, the aqueous layer of which was collected. The aqueous solution was adjusted to pH 2.0-2.5 with 6 N-hydrochloric acid solution and left to cool at a temperature of 0 to 5° C. for one hour, followed by filtering the deposited crystal. The filtered crystal was washed with 150 ml of cold water and 200 ml of acetone, in sequence, and then dried, thereby giving 19.5 g (87% yield) of the title compound as a pale yellow solid. Melting Point(° C.): 200-230(decomposition) 1 NHR :(d, D 2 O-NaHCO 3 ); 3.7(s, 2H), 4.8-5.8(m, 5H), 6.9(dd, 1H, J=12 Hz, 18 Hz) As apparent from the above description and Examples, the present invention provides the process for the preparation of the cephalosporin derivative, wherein the compound of the formula (III) is reacted with the new thiazole compound of the formula (II), as the reactive organic acid derivative, to give the cephalosporine derivative of the formula (I). Such a process does not require the deprotection step and is reduced in production step, as compared with the processes according to the prior art. Furthermore, as the reactive organic acid derivative used in the process of the present invention is the acid chloride of the stable crystalline form, it allows the acylation reaction with the compound of the formula (III) to be completed clean in a quantitative view with little or no production of by-products. In addition, the compound of the formula (II) can be stored in the form of acid chloride and is thus easy to use. As a result, the present invention provides the more inexpensive and new acylation process for the preparation of the cephalosporine derivatives having the compound of the formula (II) at a 7-position. Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.	The present invention relates to a new, simple, and easy process for preparing cephalosporin antibiotics of the following formula (I), such as ceftazidime and cefixime. The process comprises acylating a 7-amino cephalosporanic acid derivative of the following formula (III) with a crystalline aminothiazole compound of the following formula (II): wherein R 1 and R 2 are the same or different and independently represent H, a C 1-4 alkyl or C 3-5 cycloalkyl group, R 4 represents acetoxymethyl, methylpyridine, or vinyl, X represents chlorine or bromine, and the acid in the acid addition salt represents an inorganic acid, such as hydrochloric acid, or an organic acid, such as formic acid or acetic acid.	2
CROSS REFERENCE TO RELATED PATENT APPLICATIONS [0001] Patent application Ser. No. ______ (Attorney's Docket No. RPS920020097US1) assigned to the Assignee of the present invention and incorporated herein by reference describes a Flow Control System that discards Best Effort packets retroactively after occupancy in a queue with Premium packets. FIELD [0002] The present invention relates to congestion management in computer networks in general and, in particular, to manage flow control in response to congestion. BACKGROUND [0003] A switch is a network node that directs datagrams on the basis of Medium Access Control (MAC) addresses, that is, Layer 2 in the OSI model well known to those skilled in the art [see “The Basics Book of OSI and Network Management” by Motorola Codex from Addison-Wesley Publishing Company, Inc., 1993]. A switch can also be thought of as a multiport bridge, a bridge being a device that connects two LAN segments together and forwards packets on the basis of Layer 2 data. A router is a network node that directs datagrams on the basis of finding the longest prefix in a routing table of prefixes that matches the Internet Protocol (IP) destination addresses of a datagram, all within Layer 3 in the OSI model. A Network Interface Card (NIC) is a device that interfaces a network such as the Internet with an edge resource such as a server, cluster of servers, or server farm. A NIC might classify traffic in both directions for the purpose of fulfilling Service Level Agreements (SLAs) regarding Quality of Service (QoS). A NIC may also switch or route traffic in response to classification results and current congestion conditions. [0004] Network processing in general entails examining packets and deciding what to do with them. This examination can be costly in terms of processing cycles, and traffic can arrive irregularly over time. Consequently, network nodes in general provide some amount of storage for packets awaiting processing. During episodes of congestion, some arriving packets might be purposefully discarded to avoid uncontrolled overrunning of the storage. This is flow control. [0005] A common prior art flow control is called Random Early Detection (RED). As queue length grows from 0 to full storage capacity, RED at first transmits all packets into the queue, then, if occupancy exceeds a threshold Lo>=0%, a decreasing fraction of packets into the queue, and finally, if occupancy exceeds a threshold Hi<=100%, completely discarding all arriving packets. For queue occupancy Q that is between Lo and Hi, the fraction T of packets transmitted can be a linear function of the following form: T ( Q )=1−(1 −T min)( Q−Lo )/( Hi−Lo ) [0006] Here Tmin is a minimum transmitted fraction reached as Q increases to Hi. Many variations on this theme are practiced in the prior art; for example, Q might actually be an exponentially weighted moving average of queue occupancy. [0007] The use of RED or its variants unfortunately can imply some undesirable consequences including: [0000] 1. Methods ignore rate of change (queue going up, down) [0000] 2. High thresholds can cause high latency [0000] 3. Low thresholds can cause burst-shaving (low utilization) [0000] 4. There is no direct relationship between thresholds and performance [0000] 5. Administrative input needed as offered loads change [0000] 6. Hand-tuning thresholds widely recognized as difficult [0000] 7. Little or no guidance in vendor documents. [0008] In view of the above, more efficient apparatus and methods are required to make flow control decisions in high-speed networks. SUMMARY OF THE INVENTION [0009] The present invention describes a system and method for making intelligent, high-speed flow control decisions. [0010] At discrete time intervals of length Dt, the value of a transmit probability T is refreshed. How it is refreshed is included in the present invention. As packets arrive at flow control during a time interval of duration Dt, the current value of T is compared to a random number. The flow control transmits the packet into the queue for subsequent processing if the value of T is greater than or equal to the value of the random number. Flow control discards the packet if the value of T is less than the random number. [0011] The period of flow control update is denoted Dt. In a preferred embodiment, if the total capacity of the storage queue is denoted Qmax and if the maximum rate of flow of packets sent to or from the storage buffer is denoted S, then the time interval Dt is defined by Dt=Qmax/(8S). As used in this document, the symbol * means multiplication. Therefore the maximum possible change in the occupancy of the queue in any time interval Dt is ⅛ of the queue storage capacity Qmax. [0012] Denote queue occupancy Q at time t−Dt and at time t are as Q(t−Dt) and Q(t) respectively. Denote the value of the transmit probability T at time t as T(t). As an algorithm the present invention consists using inputs Q(t−Dt), Q(t), and T(t) to calculate the next transmit probability T(t+Dt). [0013] The present invention includes calculation at time t the value T(t+Dt) of transmit probability to use during the time interval [t, t+Dt] by application of said algorithm. The inputs to the algorithm are the previous transmit probability T(t) used during the interval [t−Dt, t], the queue occupancy Q(t) at time t, and the queue occupancy Q(t−Dt) at time t−Dt. Details are given below. [0014] In essence a current transmit probability T(t) is a function of past queue occupancy Q(t), current queue occupancy and past transmit probability. [0015] A summary of constants appearing in the invention follows: S the maximum possible input or output rate to the storage queue Qmax the maximum capacity of the queue Dt the flow control time interval; in a preferred embodiment, Dt=Qmax/(8S) Q0 a low queue threshold; in a preferred embodiment, Q0=Qmax/8 Q1 a high queue threshold; in a preferred embodiment, Q1=3Qmax/8 K0 a moderate rate of transmit probability exponential decay; in a preferred embodiment, K0= 31/32 K1 a high rate of transmit probability exponential decay; in a preferred embodiment, K1=¾ Inc0 a rate of linear increase; in a preferred embodiment, Inc0= 1/128 Inc1 a rate of linear increase; in a preferred embodiment, Inc1= 1/128 [0025] A summary of variables appearing in the invention follows: T(t) the transmit probability enforced in the time interval [t, t+Dt]; the value T(t) must be stored for use in the calculation of T(t+Dt). Q(t) the queue occupancy (i.e. Length of queue measured in packets, bits, etc.) at time t; the value Q(t) is used in the calculation of T(t) and must also be stored for use in the calculation of T(t+Dt). [0028] The present invention includes the use of the following algorithm with steps to update transmit probability T(t). [0000] 1. Determining Q(t). [0029] 2. If Q(t) is less than a low threshold denoted Q0, then T(t+Dt)=minimum { 1 , T(t)+Inc0} where Inc0 is an increment constant greater than 0 and less than 1. In a preferred embodiment, the value of the low threshold is ⅛ of total queue capacity and the value of Inc0 is 1/128. [0030] 3. Else, if Q(t) is above a high threshold denoted Q1, then T(t+Dt)=K0T(t) where K0 is a constant greater than 0 and less than 1. In a preferred embodiment, the value of the high threshold is ⅜ of the maximum queue capacity, and the value of K0 is ¾. In an alternative embodiment, 0<Q0=Q1<Qmax. [0000] 4. Else, if Q(t) is greater than or equal to Q(t−Dt), then T(t+Dt)=K1T(t) where K1 is a constant greater than K0 and less than 1. In a preferred embodiment, the value of K1 is 31/32. [0000] 5. Else, T(t+Dt)=minimum { 1 , T(t)+Inc1} where Inc1 is an increment constant greater than 0 and less than 1. In a preferred embodiment, the value of Inc1 is the same as Inc0, namely, 1/128. [0031] Thus the present invention can differentiate between a first scenario in which queue value is moderate (between Q0 and Q1) and constant or increasing and a second scenario in which queue value is moderate and decreasing. [0032] The present invention includes use of control theory in place of intuitive methods. For the special case of constant input to the queue and constant service rate from the queue, this enables complete characterization of equilibrium states, meaning states at which the transmit probability has reached a value such that queue occupancy is constant. If the value of Q is constant, then Q(t−Dt)=Q(t). It can be shown that such constant input and service rates will lead to one of the following equilibrium states. [0000] 1. If the input rate is less than the service rate, then at the equilibrium state Q(t−Dt)=Q(t)=0. [0000] 2. If the input rate is greater than the service rate by a factor of up to about 4, then at the equilibrium state Q(t−Dt)=Q(t)=Q0, the lower queue threshold. In a preferred embodiment, Q0 is ⅛ of the storage capacity of the queue. [0033] 3. If the input rate is greater than about four times the service rate and the service rate is still positive, then at the equilibrium state Q(t−Dt)=Q(t)=Q1, the upper queue threshold. In a preferred embodiment, Q1 is ⅜ of the storage capacity of the queue. [0034] 4. If the service rate is zero and the input rate is positive, then the queue approaches an equilibrium state Q(t−Dt)=Q(t) that is less than the storage capacity of the queue. In a preferred embodiment with Q1=3Qmax/8 and K0=¾, the equilibrium state is at most about Q1+(Qmax/8)(1/(1−K0))=7Qmax/8, that is, ⅞ of the storage capacity of the queue. BRIEF DESCRIPTION OF THE DRAWINGS [0035] FIG. 1 shows a flow control in accordance with the teaching of the present invention that limits the occupancy of a queue by discarding, if necessary, some packets rather than transmitting them into the queue. [0036] FIG. 2 shows a flow chart for updating flow control transmit probability T(t) to obtain transmit probability T(t+Dt). [0037] FIG. 3 shows a flow chart for making a decision to transmit or discard a packet. [0038] FIG. 4 shows a two-dimensional graph that is useful in presentation of the present invention. The horizontal axis is the value of the present queue occupancy Q(t) of the system. The vertical axis is the value of the previous queue occupancy Q(t−Dt). The dashed line in FIG. 4 denotes the state that Q(t)=Q(t−Dt). In equilibrium the value of Q is constant, so the state of the system will be during equilibrium somewhere on the dashed line. [0039] FIG. 5 shows regions of two-dimensional space with axes again representing the present queue occupancy Q(t) and the previous queue occupancy Q(t−Dt). In different regions of this space, different rules for updating T are applied. The update functions are in accordance with the teaching of the present invention. Furthermore, along the equilibrium line with Q(t)=Q(t−Dt) three distinguished equilibria are shown. [0040] FIGS. 6A, 6B , and 6 C show performance of the invention over 500 time steps each equal to Dt. The graphs are actual outputs of a system modeled according to teachings of the present invention. DETAILED DESCRIPTION [0041] Referring to FIG. 1 , the invention specifies a flow control method provided in a network device sometimes called a node or communications system 100 coupled to communications network 110 which shall be public switch network, internet, private network, etc., or any combination of the named network. The network device 100 could be a router, switch, Network Interface Card (NIC) or more generally a machine capable of both switching and routing functions based upon classification results and current congestion conditions. The switching and routing functions may be carried out by a Network Processor chip, such as PowerNP NP4GS3 manufactured by IBM® Corporation, operatively mounted in the machine. The flow control mechanism to which the present invention relates is identified by numeral 111 whereas mechanisms providing the other functions (such as classification routing, etc.) Are collectively represented by the block labeled 112 . Because the mechanisms that perform the other functions are not part of the present invention further reference to them will not be made. [0042] Still referring to FIG. 1 traffic enters with an offered load 101 . Flow control 103 must decide for each packet whether to transmit the packet 105 into a queue 107 or to discard the packet 108 . Packets transmitted into the queue 107 are subsequently processed 109 . Queue monitoring mechanism (Queue MM) 114 monitors queue status and forwards information to the flow control 103 . Queue status, such as length of queue, can be measured in several ways. For example, sensors (not shown) can be positioned at selected locations on the queue to output signals when queue level reaches the position of the sensor. Another technique counts packets or frames as they enter the queue. These and other monitoring techniques are known in the prior art and will not be discussed further. [0043] Referring to FIG. 2 , a flowchart for updating the transmit probability from T(t) to T(t+Dt) is presented. The update of old time t to current time t is designated by the symbol :=, meaning the new value of t is derived from the previous value of t by a formula t+Dt. With period Dt, first the queue occupancy Q(t) at time t is measured 201 . The value of Q(t) is compared 203 to a threshold Q0. If Q(t) is less than or equal to Q0, then T is updated by a linear increase 205 . If Q(t) is greater than Q0, then Q(t) is compared 207 to a second threshold Q1. If Q(t) is greater than Q1, then T is updated by an exponential decrease 209 . If Q(t) is less than or equal to Q1, then Q(t−Dt) is recalled 211 . Then Q(t) is compared to Q(t−Dt) 213 . If Q(t) is greater than or equal to Q(t−Dt), then T is updated by an exponential decrease 215 . If Q(t) is less than Q(t−Dt), then T is updated by a linear increase 217 . In all cases, the value of Q(t) is then stored 219 . The value oft is iterated by Dt 221 . Then the update of T begins anew 201 . [0044] Referring to FIG. 3 , a flowchart for making a decision to transmit or discard a packet is presented. First a packet arrives 301 . The current value of the transmit probability T is fetched 303 . A fresh random number R is generated by a random number generator 305 . The value of R is fetched 307 . T and R are compared 309 . If T is greater than or equal to R, then the packet is transmitted into the queue 311 . If T is less than R, then the packet is discarded. In either case, the system recycles to 301 as a new packet arrives. [0045] Referring to FIG. 4 , a state space with two axes is presented. The axes are the current queue occupancy value Q(t) 401 and the previous queue occupancy value Q(t−Dt) 403 . At equilibrium with constant offered load and service rate, Q(t)=Q(t−Dt). The general equilibrium condition is the dashed line 405 . [0046] Referring to FIG. 5 , three special equilibrium states in the state space of FIG. 4 are detailed. Values selected for this figure are as in the preferred embodiment. Again the present queue occupancy Q(t) 501 , the previous queue occupancy Q(t−Dt) 503 , the general equilibrium condition 505 are shown. Within different regions of the graph, different formulas are used to update the transmit probability T. Note again the use of := to designate the update, that is, deriving the new value of T from the old. During no congestion, the equilibrium state is (0, 0) 507. During light congestion, the equilibrium state is (⅛, ⅛) 507 if maximum queue capacity Qmax is normalized to 1. During heavy congestion, the equilibrium state is (⅜, ⅜) 511 if maximum queue capacity Qmax is normalized to 1 . If service rate is reduced to zero, then the equilibrium state can be anywhere on the line 505 up to (⅞, ⅞). [0047] Referring to FIGS. 6A, 6B and 6 C, performance graphs are presented. In FIG. 6A the queue processor service rate S is specified in the experiment for 500 time steps each equal to Dt. At first the value of S is the full drain rate ⅛, following from the choice of Dt in the preferred embodiment. Queue occupancy in FIG. 6B is zero. The transmit probability in FIG. 6C is 1. Then S is suddenly reduced to zero at approximately the twentieth time step. Queue occupancy in FIG. 6B rises to about ⅞ in normalized units so that Qmax=1. The transmit probability in FIG. 6C falls to nearly zero. Then at about the seventieth time step, the service rate is suddenly increased to 0.05, that is, 0.05/0.125=0.4 times the constant offered rate of 0.125. This is shown in FIG. 6A . As shown in FIG. 6B , the queue to nearly 0, then increases to ⅛, then value of Q0 in the preferred embodiment. The value of T in FIG. 6C rises and eventually reaches an equilibrium of about 0.4, as it must due to the overload ratio. [0048] In summary, the traffic enters the system at a constant rate equal to Qmax/(8Dt). FIG. 6A depicts a variable processor send rate S (chosen to illustrate the response of the invention). For about 20 time steps the value of S is the same as the input rate, namely, ⅛=0.125 of the queue capacity. Therefore the system transmits all packets into the queue. The packets are processed as soon as they arrive and the queue stays empty. Then the rate S falls to 0 for about 50 additional time steps. Then the rate S becomes 0.050 for the remainder of the time steps. FIG. 6B depicts the resulting queue occupancy Q. At first it is zero, then it rises to a maximum value of about ⅞=0.875, then it falls to a long-term equilibrium value of about ⅛=0.125. FIG. 6C depicts the value of the transmit probability T. At first it is 1, then it falls to nearly 0 (indistinguishable on the graph from 0), then it rises to a long-term equilibrium value of about 0.40. [0049] In a preferred embodiment, if the total capacity of the storage queue is denoted Qmax and if the maximum rate of flow into or from the storage buffer is S, then a time interval Dt for updating the flow control is, in a preferred embodiment, defined by Dt=Qmax/(8S). Denote queue occupancy Q at time t−Dt and at time t as Q(t−Dt) and Q(t) respectively. Furthermore, the value of the transmit probability T at time t, that is, T(t) is used. As an algorithm the present invention includes using inputs Q(t−Dt), Q(t), and T(t) to calculate the next transmit probability T(t+Dt) by use of the following steps: [0050] 1. If Q(t) is less than a low threshold denoted Q0, then T(t+Dt)=minimum {1, T(t)+Inc0} where Inc0 is an increment constant greater than 0 and less than 1. In a preferred embodiment, the value of the low threshold is ⅛ of total queue capacity and the value of Inc0 is 1/128. [0051] 2. Else, if Q(t) is above a high threshold denoted Q1, then T(t+Dt)=K0T(t) where K0 is a constant greater than 0 and less than 1. In a preferred embodiment, the value of the high threshold is ⅜ of the maximum queue capacity, and the value of K0 is ¾. [0000] 3. Else, if Q(t)>=Q(t+Dt), then T(t+Dt)=K1*T(t) where K1 is a constant greater than K0 and less than 1. In a preferred embodiment, the value of K1 is 31/32. [0000] 4. Else, T(t+Dt)=minimum {1, T(t)+Inc1} where Inc1 is an increment constant greater than 0 and less than 1. In a preferred embodiment, the value of Inc1 is the same as Inc0, namely, 1/128 [0052] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teaching and advanced use of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims.	The decision within a packet processing device to transmit a newly arriving packet into a queue to await processing or to discard the same packet is made by a flow control method and system. The flow control is updated with a constant period determined by storage and flow rate limits. The update includes comparing current queue occupancy to thresholds and also comparing present queue occupancy to previous queue occupancy. The outcome of the update is a new transmit probability value. The value is stored for the subsequent period of flow control and packets arriving during that period are subject to a transmit or discard decision that uses that value.	7
FIELD OF THE INVENTION [0001] This invention relates generally to the field of livestock feed and more particularly to methods for extending the shelf life of livestock feed. BACKGROUND OF THE INVENTION [0002] Distillers' grain (“DG”) is a co-product produced when cereal grains are used in the production of fuel or beverage ethanol. An example of a process that produces distillers' grain as a co-product is disclosed in U.S. Pat. No. 5,439,701 filed Apr. 15, 2001, which is hereby incorporated by reference in its entirety. [0003] The amount of DG being produced is increasing both because the number of fuel ethanol production facilities is increasing, and also because production has increased in existing facilities. Distillers' grain is comprised primarily of protein, fat (oil), fiber, minerals and water, which make it a good feed source for dairy and beef cattle, swine and poultry. [0004] There are many factors that contribute to the quality of the DG including initial grain quality and the processing conditions. The DG typically leaves the ethanol production process in a sterile condition because of the high temperatures associated with ethanol production. Thus, mold and yeast contaminate the DG post-production, which may occurred in transportation, passing through contaminated feed-handling equipment, such as augers, elevators, drag lines, bagging equipment and trucks. In storage, feed can become contaminated by storage bins or by contact with dust, insects, rodent, birds and other animals. [0005] Furthermore, DG can be high in moisture content. This moisture combined with DG's composition, namely protein, fat and fiber, provide a favorable environment for mold and yeast growth. Thus, mold and yeast growth typically reduce the untreated DG's shelf life to approximately three days. This creates logistical problems for the ethanol facilities producing the DG and the livestock facilities that feed it. Without extending DG's shelf life, the ethanol facilities producing it are limited to how long they can store the product and to how far they can ship it. Livestock facilities are also limited to how long they can store the DG before mold and yeast growth prevent its use. [0006] In some cases, the DG is dried to reduce its moisture content. Drying the DG may inhibit the growth of mold and yeast depending on how much moisture is removed, but drying the DG can be expensive and not always desired. Furthermore, moisture may be reintroduced to the DG during shipping or storage, which would promote the growth of mold and yeast. [0007] Because DG is contaminated after production, heating, irradiation and other sterilization techniques may not be as effective at increasing the shelf life of DG as the addition of chemical preservatives, which continue to work through the life of the product. Thus, chemical preservatives, which remain with the DG, work better to extend the shelf life of the feed. There are numerous materials that are known to function as chemical preservatives in livestock feed, including, for example: ascorbic acid, ascorbyl palmitate, benzoic acid, butylated hydroxylanisole, butylated hydroxytoluene, calcium ascorbate, calcium propionate, calcium sorbate, citric acid, dilauryl thiodipropionate, distearyl thiodipropionate, erythrobic acid, ethoxyquin, formic acid, methylparaben, potassium bisulfate, potassium metabisulfate, potassium sorbate, propionic acid, proply gallate, propylparaben, guaiac gum, sodium ascorbate, sodium benzoate, sodium bisulfate, sodium metabisulfate, sodium nitrite, sodium propionate, sodium sorbate, sodium sulfite, sorbic acid, stannous chloride, sulfur dioxide, tertiary butyl hydroquinone, thiodipropionic acid and tocopherols. SUMMARY OF THE INVENTION [0008] The present disclosure relates to a feed containing hydrogen peroxide that inhibits mold and yeast growth. This disclosure also relates to a method for applying hydrogen peroxide to the feed. [0009] In one embodiment, distillers' grain is combined with hydrogen peroxide to inhibit mold and yeast growth and to extend the shelf life of the feed. Feed as used herein means any feed, major or minor ingredient or any component thereof. Another embodiment of the present disclosure relates to a method for applying hydrogen peroxide onto a feed to extend the shelf life of the feed. In this embodiment, the feed stream enters a mix housing, which defines a mix chamber and is moved through the mix chamber by an actuating device contained therein. Adjacent to the mix housing is a spray housing, which defines a spray chamber. The feed stream passes through a volume created by a portion of the mix chamber that is in fluid communication with the spray chamber. At least one nozzle is coupled to the spray housing and connected to an aqueous solution of hydrogen peroxide and, in some cases, to an air line. The nozzle creates a fog of the aqueous solution of hydrogen peroxide in the spray chamber and in a volume of the mix chamber adjacent to the spray chamber. The fog of hydrogen peroxide is deposited on the feed stream. As the feed stream continues through the mix chamber, the actuating device mixes the hydrogen peroxide and the feed stream. BRIEF DESCRIPTION OF THE DRAWING [0010] The drawing is a diagram of a system for applying the hydrogen peroxide according to the principles of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0011] The inventors have found a novel way to extend the shelf life of feed products, such as those containing DG, by using hydrogen peroxide to prevent the growth of mold and yeast. Typically, visual detection of mold and yeast does not occur for 36 hours in feed containing ingredients, such as, DG. This may vary, however, depending the feeds content and environment. Tests show that adding hydrogen peroxide to DG inhibits the growth of mold and yeast. For example, in a control sample, with a mass of approximately 72 grams of DG, mold and yeast were visually detected after about 3 days. When the DG was mixed with an aqueous solution of hydrogen peroxide such that the mixture contained 2.0% by weight hydrogen peroxide mold and yeast were not visually present for 174 hours or about 7 days. When the DG was mixed with an aqueous solution of hydrogen peroxide such that the mixture contained 4.1% by weight hydrogen peroxide mold and yeast were not visually present for 310 hours or about 13 days. When the DG was mixed with an aqueous solution of hydrogen peroxide such that the mixture contained 6.1% by weight hydrogen peroxide mold and yeast were not visually present for 406 hours or about 17 days. When the DG was mixed with an aqueous solution of hydrogen peroxide such that the mixture contained 6.4% by weight hydrogen peroxide mold and yeast were not visually detected after 30 days, at which point the experiment was terminated. These weight percentages of hydrogen peroxide are by way of example only. The amount of hydrogen peroxide could be any amount sufficient to inhibit the growth of mold and yeast on a feed product. [0012] The test did show some variability in the performance of the hydrogen peroxide in reducing mold and yeast growth, such variability is likely due to varying conditions of the DG used. For example, some of the samples may have had more or less contamination from outside sources prior to the experiment, which would cause variability in the performance of the hydrogen peroxide. [0013] There are many ways in which the hydrogen peroxide can be added to the feed to obtain the desired weight percent of hydrogen peroxide to total mass of the feed. The drawing shows a system 26 that illustrates just one example system used in connection with the present disclosure to combine the feed and the hydrogen peroxide. In that example system, the feed 25 is passed through a mix housing 4 and under a spray chamber 2 such that an aqueous solution of hydrogen peroxide 16 is sprayed onto the passing feed stream 25 , or the hydrogen peroxide solution 16 is mixed with air and the mixture of air and hydrogen peroxide 16 is sprayed onto the passing feed stream. [0014] In this example embodiment, the mix housing 4 defines a mix chamber 5 and a mix chamber opening 6 . The mix housing 4 is used to transport material from one point in a feed processing plant to another point in the feed processing plant. Inside the mix chamber 5 is an actuating device 7 . While inside the mix housing 4 , feed stream 25 is progressed through the mix chamber 5 and mixed by the actuating device 7 . The actuating device 7 can be anything capable of moving and mixing the feed stream 25 through the mix chamber 5 . [0015] The mix housing 4 has a length 30 , a width 23 and height 22 . The length 30 can be any operable length required to move the feed stream 25 from one point in the process to another, and to allow sufficient time to apply the hydrogen peroxide solution 16 . The length 30 has a first end 27 , a mid section 28 , and a second end 29 . The feed stream 25 enters the mix housing 4 at the first end 27 and exits the mix housing 4 at the second end 29 . [0016] The spray housing 1 is located adjacent to the mix housing 4 . The spray housing 1 defines a spray chamber 2 and a spray chamber opening 3 . The spray housing 1 is placed adjacent to the mix housing 4 such that the spray chamber opening 3 and the mix chamber opening 6 provides fluid communication between the spray chamber 2 and the mix chamber 5 . [0017] The spray housing 1 is located adjacent to the mix housing 4 such that the aqueous solution of hydrogen peroxide 16 is deposited onto the feed stream 25 to allow the feed stream 25 sufficient time to mix in the mix chamber 5 . A spray nozzle 8 is coupled to the spray housing 1 and is fed by an air line 12 and a hydrogen peroxide line 17 . Spray nozzle 8 sprays a mixture of air and hydrogen peroxide solution 16 through the spray chamber 2 and into the mix chamber 5 and gets deposited on the feed stream 25 . Alternatively, spray nozzle 8 could spray the aqueous solution of hydrogen peroxide with out air. The aqueous solution of hydrogen peroxide 16 could also contain other feed additives, for example, propylene glycol or yucca extract. [0018] The drawing illustrates just one of the many methods for adding the hydrogen peroxide to the feed. Other example methods of depositing the hydrogen peroxide 16 on the feed 25 are disclosed in U.S. patent application Ser. No. 10/440,432, filed May 16, 2003, which is hereby incorporated by reference in its entirety. It should be noted, however, that these are just examples of how the hydrogen peroxide could be applied to the feed to produce the desired results. There are many ways in which the hydrogen peroxide could be added to the feed to obtain the results of the present disclosure. For example, it could be batch mixed with an aqueous solution of hydrogen peroxide, or the feed could be treated multiple times depending on the feed and circumstances necessary to extend the shelf life. [0019] There are also many different formulations of feed and hydrogen peroxide that can be used depending on the conditions in which the feed will be exposed. For example, larger weight percentages of hydrogen peroxide may be used where the feed is to be shipped greater distances and thus will be stored for a longer period of time prior to consumption by the livestock. In other circumstances, the weight percent of hydrogen peroxide may be lower where less time will elapse between production and consumption by the livestock. Thus, the weight percent of hydrogen peroxide could range from a very small amount, such as 0.05% for example, to a high percent, such as 75% or higher. [0020] In one example embodiment, the amount of hydrogen peroxide to feed could be approximately 0.05 to 50.0 weight percent hydrogen peroxide to total weight of mixture. In another embodiment, the amount of hydrogen peroxide to feed could be approximately 1.50 to 20.0 weight percent hydrogen peroxide to total weight of mixture. In another example embodiment, the amount of hydrogen peroxide to feed could be approximately 2.50 to 6.0 weight percent hydrogen peroxide to total weight of mixture. [0021] It is to be understood that even though numerous characteristics and advantages of various embodiments of the present disclosure have been set forth in the forgoing description, together with the details of this composition, this disclosure is illustrative only and changes may be made in detail especially in matters of formula and methods within the principles of the present disclosure, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.	A feed composition comprising hydrogen peroxide that resists mold and yeast growth is disclosed along with methods for applying the hydrogen peroxide to the feed composition. In one embodiment the major ingredient of the feed composition is a distillers' grain, which is combined with hydrogen peroxide to prevent mold and yeast growth and extend the life of the feed product.	0
BACKGROUND TO THE INVENTION The invention relates to systems of the type comprising a triggering element such as a thyristor which is triggered by a relaxation oscillator or the like. It relates more particularly to electrical igniters for domestic household appliances or the like. It is known, particularly in this special application to igniters (taken solely as an example), that systems of the type in question comprise for the generation of ignition sparks a voltage raising pulse transformer wherein the sudden discharge of an energy store capacitor from a thyristor or the like, itself controlled by a relaxation oscillator causes the emission of a high pulsating voltage at the ignition electro terminals close to the igniters in question resulting in sparks being formed. The operation of such igniters is controlled by a switch operated either manually by a push button or indirectly by a mechanism linked with the operation of gas taps or the like. This switch must be kept closed throughout the pulse formation period until ignition occurs. It represents a constraint for the operator because he cannot use his hand during the period of operation. BRIEF SUMMARY OF INVENTION The invention proposes that by adding appropriate means the operation can be instantaneous, i.e. in the form of a single pulse, whereby thyristor triggering stops automatically after a predetermined time. To achieve this object with the relaxation oscillator is combined a timing mechanism which is able to progressively reduce the amplitude of the triggering pulses which it supplies to the thyristor until a value is reached which is insufficient to bring about triggering. Thus, starting with an instantaneous initial excitation, the thyristor is triggered during a certain time which is a function of the characteristics of the timing mechanism and without intervention on the part of the operator being necessary. This timing mechanism substantially comprises the assembly of a series resistance in the oscillator circuit and in parallel with a capacitor and a series diode, so that this assembly is combined with the relaxation oscillator and more particularly with the capacitor thereof. Its effect is such that the capacitor of the timing mechanism progressively charges with each relaxation pulse, hence there is a decrease in the amplitude of the said pulses until they are below the threshold intensity for releasing the thyristor. In such an assembly where the relaxation oscillator for example comprises in per se known manner the assembly of a capacitor and a neon tube or other identical ignitable device having a switching threshold, it should be noted that the said assembly remains energized, i.e. it continues, even when the pulses have dropped below the above indicated threshold intensity, to supply pulses which are however inadequate for triggering the thyristor. Thus the appliance is always ready to operate again (through reconnecting it by instantaneous discharge of the timing mechanism capacitor) so that there is no danger of ignition delays as is the case with known appliances. Other than these arrangements, the invention is directed towards other arrangements which can be preferably used at the same time and which will be explained in greater detail herinafter. It particularly aims at a certain applicationmode (where applied to igniters or burners on domestic appliances or the like) as well as to certain embodiments of the said arrangements. It aims more particularly and as new industrial products to assemblies of the type in question wherein these arrangements are used as well as to the special components used in producing them and the installations, more particularly domestic appliances in which they are incorporated. BRIEF DESCRIPTION OF THE DRAWINGS Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which by way of illustration show preferred embodiments of the present invention and the principles thereof and what are now considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the scope of the appended claims. In the drawings show: FIG. 1 an electrical circuit diagram for an igniter according to the invention. FIG. 2 comprises four diagrams, a, b, c, d showing the reciprocal pulses of the various circuits of the appliance. FIGS. 3 and 4, in schematic perspective representation, a gas tap provided with switching means combined with an igniter of the present type in two operating positions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the invention and more particularly according to its preferred application modes and embodiments wherein it is proposed for example, among other possible applications, to produce an electrical igniter for gas appliances with a thyristor triggered by a relaxation circuit one proceeds in the following or in a similar manner. In FIG. 1 is shown the essential components and elements of an igniter of the known type which are as follows: a supply circuit M comprising the rectifier devices of the input voltage (220V or 110V), thus capacitor C 1 , resistance R 1 , R 2 and diodes D 1 , D 2 . an energy distribution circuit N from a thyristor Q 1 which controls a voltage raising transformer T 1 and an energy store capacitor C 2 with a parallel diode D 3 . and a control circuit P comprising a relaxation oscillator with a neon tube L 1 combined with an integrating circuit supplied by a capacitor C 3 and a resistance R 3 so that to the triggering electrode of thyristor Q 1 are supplied triggering pulses combined with resistances R 4 , R 5 (and another resistance such as R 6 which will be described hereinafter) which meter the amplitude. The intensity of these current pulses is made relatively high so that in all circumstances it is above the triggering current Igt of the thyristor but still being sufficiently low so as not to impair the characteristics of neon tube L 1 . Without the timing mechanism, to be discussed hereinafter, the pulses would always have an intensity greater than Igt so that at the top of the appliance it would always be necessary to provide a switch which would have to be closed throughout ignition and opened again after ignition had taken place. According to the invention, to the oscillator is added a timing mechanism TP whose function is to progressively reduce the amplitude of the pulses supplied by the thyristor oscillator until they are below Igt. Therefore ignition is stopped automatically in such a way that it is no longer necessary to operate a control switch after an initial connecting pulse has been given. Thus, this device essentially comprises a capacitor which charges during each pulse which thereby modifies the characteristics of the system without however changing the pulse recurrence (frequency which is about 2 Hz). Thus, the present device substantially comprises for example: a capacitor C 4 combined with the diode D 4 and a parallel resistance R 6 arranged in series on one of the terminals of capacitor C 3 of the relaxation oscillator, whereby the said resistance R 6 is also in series in the discharge circuit of the relaxation oscillator. a resistance R 7 combined with a switch K 1 at the terminals of capacitor C 4 in order to permit the discharge of the latter whenever desired. Capacitor C 4 has a capacitance which is greater than that of capacitor C 3 , e.g. 10 to 20 times greater. The system which is connected to supply device M, operates in the following manner. With diode D 4 appropriately orientated, the successive pulses from relaxation device P served to charge in successive levels capacitor C 4 which therefore assumes an increasing voltage. When the charging of C 4 is complete only a negligible current passes through diode D 4 . Thus, the discharge current of capacitor C 3 of relaxation circuit P is limited by the total resistance of the discharge circuit comprising in addition to resistance R 4 and the trigger cathode gap of thyristor Q 1 shunted on resistance R 5 , the above mentioned resistance R 6 . Thus, through an appropriate choice of the value of resistance R 6 it is possible to give any predetermined value to discharge current C 3 which will be reached asymptotically on completing the charging of capacitor C 4 . This value will be chosen so that the thyristor triggering current, Igt, is no longer reached. Thus, finally the thyristor only supplies to distribution circuit N a limited number of pulses. After such a cycle, a new cycle can be obtained at any time by means of a connecting pulse, i.e. momentarily closing switch K 1 so as to almost instantaneously discharge capacitor C 4 resulting in pulses whose intensity is greater than Igt and which gradually decrease as described hereinbefore. Thus, the operation of the appliance comprises momentarily operating switch K 1 . FIG. 2 shows the speed and appearance of these phenomena. In FIG. 2 can be seen: at a, schematically, the control pulses A corresponding to the closing of K 1 , i.e. the discharge of capacitor C 4 , at b, the stepped curve 3 of capacitor C 4 , at c, the curve C of the pulses supplied by P to the trigger of thyristor Q 1 , these pulses being of constant frequency but of variable intensity, and at d, the high voltage pulses D supplied by the transformer synchronously with pulses C, in the zones where they are greater than Igt. The frequency of the pulses will be determined according to the characteristics of the relaxation circuit and as indicated hereinbefore will be of the order of 2 Hz. For resistance R 6 a value which is considerably lower than the value of resistance R 3 of the integrating circuit of the relaxation oscillator is chosen so that the recurrence frequency f is not greatly influenced by the presence of timing circuit TP. In this way, the operating frequency of the igniter is stable during timing period t (FIG. 2). It should be noted that the relaxation oscillator continues to function permanently during the period T separating two ignition phases due to the presence of resistance R 6 which recloses the discharge circuit of capacitor C 3 . When applied to domestic igniters, this leads to the advantage of eliminating delays on igniting neon tubes. It is in fact known that when these components are placed in the inoperative state in the dark, as can happen inside a domestic appliance, due to recombination the free ions of their atmosphere can disappear, these normally being regenerated by photoelectric emissions of the electrodes and are necessary to obtain ignition. Thus, ignition delays which are sometimes of the order of minutes are avoided whereby the periodic lighting up of the neon tube due to the permanent operation of the relaxation oscillator maintains the constant presence of free ions. A timing adjustment or a compensation of the dispersions of the characteristics of the components can be obtained, if necessary, by modifying the value of resistance R 5 shunted in the trigger-cathode gap of thyristor Q 1 . Thus, the triggering pulses applied to the thyristor can be made to vary within very wide limits provided that they reliably trigger the thyristor in the timing phase. Therefore, they can be made much lower than the triggering current Igt as shown in FIG. 2 at C. This represents a safety factor protecting the thyristor from undesired erratic releases, more particularly in the case of momentary variations in the mains voltage. Switch K 1 which starts up the igniter by discharging capacitor C 4 can be operated, as stated hereinbefore, through controlling a tap, e.g. in the following manner with reference to FIGS. 3 and 4. FIG. 3 shows a gas control tap 1 which is closed in its inoperative position. The main rotation movement of spindle 2 of the said tap is limited by means of a pin 3 fixed to the said spindle and which moves in a slot 4 of bearing 5 integral with the tap. In the inoperative position shown in FIG. 3, pin 3 engages in a recess 6 of slot 4 under the action of a not shown inner restoring spring which blocks any possible rotation movement of the tap spindle. As known in such a tap the opening operation is performed, as shown in FIG. 4, by initially pressing on spindle 2 by means of control button 7 to bring about unlocking whereby pin 3 leaves its recess 6 and then actuates spindle 2 in the direction of arrow f. At the end of the opening movement, the operator releases the button in such a way that the assembly is returned by the restoring spring and the pin abuts against an edge 8 of notch 4, for example at 3 1 . A to and fro movement is used for controlling switch K 1 . To this end, for example, another pin 9 carried by spindle 2 acts on a blade 10 which in turn acts at 11 on contact 12 of switch K 1 . It can be seen that in the closed position of the tap (FIG. 3), contact 12 is closed whereas on operating the tap in the opening direction thereof the said contact instantaneously closes, as shown in FIG. 4, and then opens again when the operator releases control button 7. At 3 1 , pin 3 abuts against edge 8 where blade 10 returns to its initial position. Thus, ignition is started by operating gas tap button 7. It should be noted that the closing of the tap does not require any unlocking action because the return to the inoperative position is performed by simple reverse rotation without actuating switch K 1 . It is easily possible to conceive other arrangements giving the same effect, more particularly by means of a blade 10 of appropriate configuration operating the same switch K 1 from several taps. Thus, no matter what embodiment is adopted, assemblies and particularly igniters are obtained whose fundamental operation has been adequately described hereinbefore without it being necessary to give further details and having numerous advantages relative to the hitherto known assemblies of this type. The particular advantages are that it is possible to operate the appliance by a single control pulse, the neon tube or the like is always ready to operate and the assembly system is extremely simple. While there has been described and illustrated the preferred embodiments of the invention, it is to be understood that these are capable of variation and modification and it is therefore not desired to be limited to the precise details set forth but to include such modifications and alterations as fall within the scope of the appended claims.	The invention relates to systems comprising a triggering element such as a thyristor triggered from a relaxation oscillator and relates more particularly to an electrical igniter. In this system means are provided for ensuring the automatic decrease of the intensity of the triggering pulses supplied by the oscillator so that triggering automatically stops after a predetermined time. These means comprise a timing mechanism formed by a resistance inserted in series in the discharge circuit of the oscillator with a capacitor and diode in parallel on the said resistance, the diode being oriented so as to charge the capacitor under the action of pulses supplied by the oscillator. The invention can be applied to an igniter for gas burners.	5
BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is generally related to the area of optical communications. In particular, the invention is related to a method and apparatus for regulating optical channel signals with specified wavelengths. 2. The Background of Related Art The future communication networks demand ever increasing bandwidths and flexibility to different communication protocols. DWDM (Dense Wavelength Division Multiplexing) is one of the key technologies for such optical fiber communication networks. DWDM employs multiple wavelengths or channels in a single fiber to transmit in parallel different communication protocols and bit rates. Transmitting several channels in a single optical fiber at different wavelengths can multi-fold expand the transmission capacity of the existing optical transmission systems, and facilitating many functions in optical networking. In general, each of the channel signals comes from a different source and may have transmitted over different mediums, resulting in a different power level. Without equalizing the power levels of the channel signals that are to be combined or multiplexed, some channels in a multiplexed signal may be distorted as a result of various stages of processing the multiplexed signal. On the other hand, many optical devices or systems would not function optimally when incoming signals are beyond a predetermined signal level range. In fact, the power of the incoming signals shall not be too low, neither too high. To ensure that all optical devices or systems receive proper levels of optical signals, attenuation devices are frequently used to adjust the optical signals before they reach an optical device. Many existing optical attenuation devices lack accuracy and have high feedback noise. For example, screws are often used to intrude in an optical path to disrupt or cause to reflect some of the energy in a light beam not to reach a destination so that the light beam may be attenuated. However, in practical application, it is noticed that such attenuation is hard to be controlled. Because every time, a screw is rotated either upwards or downwards, the attenuation is not monotonically changed. This is particularly related to the surface changes of the screw. Unless the tip of a screw is made perfect, the circumambiency of the tip of the screw often has some variances, which resulting in non-monotonic changes in attenuation when the screw is caused to move up and down. Although a perfect screw may be made, the eventual cost of the attenuator may not be practical. Therefore there is a need for cost-effective attenuators with monotonic attenuation. SUMMARY OF THE INVENTION This section is for the purpose of summarizing some aspects of the present invention and to briefly introduce some preferred embodiments. Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the present invention. The present invention is related to designs of optical devices and methods for attenuating a light signal. According to one aspect of the present invention, an attenuator includes a screw and a light blocker, wherein the light blocker has only translational movements when the screw is screwed in or out. To facilitate the light signal in and out, a first collimator to receive a light beam, and a second collimator to output the light beam, wherein the light beam is attenuated by the light blocker when the light is transmitted from the first collimator to the second collimator. According to another aspect of the present invention, the light blocker has a tip that is so shaped that a portion of the light beam, when hit by the tip, will reflect to a direction other than either one of the collimators. There are numerous benefits, features, and advantages in the present invention. One of them is the monotonic change in attenuation when adjusting the attenuation. Another one of the benefits, features, and advantages in the present invention is that attenuators made in accordance with the present invention possess the characteristics of simple structure, good performance, high reliability and low cost. Other objects, features, and advantages of the present invention will become apparent upon examining the following detailed description of an embodiment thereof, taken in conjunction with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: FIG. 1 shows an optical device, also referred to as attenuator, for attenuating channel signals, according to one embodiment of the invention; FIG. 2 shows a diagram of an attenuating means used in FIG. 1 , according to one embodiment of the present invention; and FIG. 3 shows is an illustration of how the attenuating means attenuates light signals between two collimators. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will become obvious to those skilled in the art that the present invention may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the present invention. Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention. Embodiments of the present invention are discussed herein with reference to FIGS. 1-3 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. FIG. 1 shows an optical device, also referred to as attenuator 100 , for attenuating channel signals according to one embodiment of the invention. The optical device 100 is utilized to attenuate the signal strengths of channel signals received at one end and output attenuated channel signals at another end. In particular, FIG. 1 shows the attenuator 100 is an integrated device. The attenuator 100 is housed in a solid housing 102 . The material of the block is preferably solid, such as stainless steel, aluminum, copper or other metal or material that has reasonably good thermal characteristics and mechanical strengths to support the components used to achieve the attenuation. In addition, it is preferable that the material can withstand the fiber straight pulling, side pulling, vibration, and mechanical shocks, and has good bounding characteristics to epoxies. As shown in FIG. 1 , the components in the housing 102 include a means 104 for attenuating signals, and two collimators 106 and 108 , both are respectively positioned on both ends of the housing 102 . In addition, external hardware is provided to couple two respective fibers with the two collimators 106 and 108 . As a result, a light beam coming from a fiber is projected onto the collimator 106 , attenuated by the attenuating means 104 , if necessary, and is then collected by the collimator 108 for output through another fiber. According to one embodiment, the collimators 106 and 108 are respectively fixed to the housing 102 by thermal epoxy, in situ, after a proper alignment of the collimators 106 and 108 to achieve a minimum loss. FIG. 2 shows a diagram of the attenuating means 104 according to one embodiment of the present invention. As illustrated, the attenuating means 104 includes an attenuation setting screw 202 , a light blocker 204 and a spring 206 , all encapsulated in a screw mating tube 208 and a spring stop washer 210 . Instead of having a screw directly attenuate a light beam, the light blocker 204 is used to attenuate a light beam. The light blocker 204 is pushed downwards by the screw 202 when the screw 202 is screwed in and upwards by the spring 206 when the screw 202 is screwed out. One of the advantages, benefits and features of the embodiment shown in FIG. 2 is that the light blocker 204 is always moved along a line or translationally. The purely translational moving of the light blocker 204 is achieved by turning in the attenuation setting screw 202 . While the locked position of the light blocker is attained by the spring 206 that is placed between the light blocker 204 and a spring stop that is attached to the screw mating tube. The spring stop can be made as part of the mating tube, or can be made separately and attached to the mating tube 208 afterward, as shown in FIG. 2 . FIG. 3 shows is an illustration of how the attenuating means 104 attenuates light signals between two collimators 106 and 108 . The light blocker 204 has a tip 302 that is preferably so shaped that a portion of the light signals, when hit the tip 302 , will reflect to a direction other than the collimator 106 . With the introduction of the tip in the optical path, the attenuation to the signal is realized. In con junction with FIG. 2 , it can be appreciated that the motion of the tip 302 is translational. Even if there is some dirt on the tip 302 , because there is no rational motion thereof, the dirt just contributes to the attenuation. The amount of the attenuation is steadily controllable. Given the description herein, those skilled in the art can appreciate that the optical attenuators made in accordance with the present invention can also resist to drastic environmental temperature variations and high humidity working condition. The present invention has been described in sufficient details with a certain degree of particularity. It is understood to those skilled in the art that the present disclosure of embodiments has been made by way of examples only and that numerous changes in the arrangement and combination of parts may be resorted without departing from the spirit and scope of the invention as claimed. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description of embodiments.	Designs of optical devices for attenuating a light signal are disclosed. According to embodiment, an attenuator includes a screw and a light blocker, wherein the light blocker has only translational movements when the screw is screwed in or out. To facilitate the light signal in and out, a first collimator to receive a light beam, and a second collimator to output the light beam, wherein the light beam is attenuated by the light blocker when the light is transmitted from the first collimator to the second collimator.	6
FIELD OF THE INVENTION This invention relates to medical devices and more particularly to infusion pumps. BACKGROUND OF THE INVENTION Infusion systems are used to administer one or more infusates to patients. Typically, infusion systems incorporate a pumping mechanism assembly which delivers infusates on a flow path at controlled rates and times. In many systems, the flow path past the pumping mechanism assembly is provided as a removable or disposable member, such as a cassette or flexible tubing, which engages the pumping mechanism assembly. An engagement mechanism is used to move the flow path and the pumping mechanism assembly into engagement with each other for infusions and out of engagement for removing the disposable member. For example, U.S. Pat. No. 4,828,545, discloses an infusion system in which the flow path is provided in a removable cassette which is mounted to the system housing. A flexible membrane in the cassette defines the flow path and pump and valve chambers. The pumping mechanism assembly, including pump and valve pistons, is moved into an engaged position in which the pump and valve pistons can engage the flexible membrane to control entry of infusates into the pump and valve chambers. The engagement of the pumping mechanism assembly also locks the cassette in place and prevents the free flow of infusates on the flow path. To remove the cassette, the pumping mechanism assembly is retracted from the cassette. A linkage is provided in the system housing to slide the pumping mechanism assembly into engagement with and retraction from the cassette. A handle on the system housing is provided to control movement of the linkage. The handle is rotatable about an axis parallel to the direction of sliding of the pumping mechanism assembly. The handle is also movable along the axis for release from a locked position, in which the pumping mechanism assembly is engaged with the cassette, to an unlocked position, in which the handle may be rotated to retract the pumping mechanism assembly. SUMMARY OF THE INVENTION The retraction mechanism for an infusion pump of the present invention provides a linkage which converts rotary motion of a handle about an axis to linear motion along a line parallel to the rotation axis. The mechanism is connected to a pumping mechanism assembly support to cause the pumping mechanism assembly support to retract from or engage with a flow path such as through a cassette. The mechanism is strong, simple, and compact, while also being intuitive to operate. The retraction mechanism includes a toggle linkage which aids in locking the mechanism in the retracted position and in biassing the mechanism to the engaged position when the handle is moved out of the locked position. The toggle linkage is coupled to a pull rod assembly which includes a linearly movable pull rod fixed to the pumping mechanism assembly support. The pull rod is supported by a bearing surface, which provides a reduced friction, linear motion. The pull rod assembly also includes a support arm which is also fixed to the pumping mechanism assembly support. The support arm provides additional stability to the motion of the pumping mechanism assembly support. The toggle linkage is coupled at an opposite end to a retraction assembly comprising a retraction shaft having the handle thereon. The shaft is biassed toward the engaged position and retained in the engaged position by a engaged position stop. Maintaining the engaged position aids in preventing unintended free flow of fluid along the flow path by, for example, accidental retraction of the pumping mechanism assembly. To retract the mechanism, the retraction shaft is first pulled out past the engaged position stop, and then the shaft is rotated until it locks into the retracted position. This two-step operation also aids in preventing accidental retraction of the mechanism. The rotation of the shaft is further limited in both directions by two additional stops, thereby limiting the translation to only the permitted and necessary positions. The retraction mechanism requires only a minimum of fasteners to attach to the chassis and allows for some adjustment when being assembled to accommodate variations in parts, such as dimensional tolerances. DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: FIG. 1 is an isometric view of the retraction mechanism of the present invention in the retracted position; FIG. 2 is a further isometric view of the retraction mechanism of FIG. 1; FIG. 3 is an isometric view of the retraction mechanism of FIG. 1 in the engaged position; FIG. 4 is a further isometric view of the retraction mechanism of FIG. 3; FIG. 5 is a further isometric view of the retraction mechanism of FIG. 1; FIG. 6 is a view of an infusion system housing incorporating the retraction mechanism of the present invention; FIG. 7 is an exploded isometric view of part of the retraction mechanism of the present invention; FIG. 8 is an isometric view of the toggle linkage of the present invention; FIGS. 9A and 9B are isometric views of the pull rod brace of the present invention; FIG. 10 is an isometric view of a toggle link of the present invention; FIGS. 11A and 11B are isometric views of the retraction link of the present invention; and FIG. 12 is an isometric view of the retraction brace of the present invention. DETAILED DESCRIPTION OF THE INVENTION The retraction mechanism 10 of the present invention is shown generally in FIGS. 1-5 in conjunction with an infusion system 12 incorporating a removable cassette (not shown). A flow path and pumping and valve chambers are provided in the cassette. The infusion system includes a chassis 14 to which is mounted a pumping mechanism assembly support 16. The pumping mechanism assembly support houses the various elements of the pumping mechanism assembly (not shown), such as the pump and valve pistons. A holster 18, into which the cassette is slid for engagement with the pumping mechanism assembly, is also mounted on the chassis 14. The retraction mechanism includes a linearly movable pull rod assembly 20, which is fixed to the pumping mechanism assembly support 16, and a retraction assembly 22, which includes a handle 24 extending outside of the infusion system housing 26 (see FIG. 6). The handle 24 is coupled to a shaft 28 which is movable linearly along an axis parallel to the direction of the pull rod assembly motion (indicated by arrow 30) and rotatable about the axis. A toggle linkage 32 interconnects the retraction assembly 22 and the pull rod assembly 20 and converts the rotary motion of the retraction assembly to the linear motion of the pull rod assembly. The pull rod assembly 20 of the retraction mechanism includes a pull rod 34 which is fastened at a first end to a wall 36 of the pumping mechanism assembly support 16, such as by a screw (not shown). The pull rod assembly also includes a support arm 38 having a main arm 40. The support arm also has a short end piece 42 and a long end piece 44 which extend at an angle from the main arm 40. A slot 46 (see FIGS. 7 and 8) is provided through the main arm 40 and the long end piece 44, discussed further below. The short end piece 42 of the support arm 38 is fastened to the wall 36 of the pumping mechanism assembly support 16, such as by a screw 48 (see FIG. 3). The long end piece 44 of the support arm 38 is fastened to a second end of the pull rod 34, such as by a screw 50. In this manner, the pull rod 34 and the support arm 38 are able to move in tandem in a direction parallel to the axis of the pull rod, indicated by the arrow 30. The pumping mechanism assembly support 16 is also able to move with the pull rod and the support arm in the direction of arrow 30 parallel to the pull rod axis. The support arm 38 provides additional support for the pumping mechanism assembly support 16 and stabilizes the motion thereof. The pull rod 34 and support arm 38 may be fastened to each other and to the pumping mechanism assembly support 16 in any other suitable manner known in the art. A pull rod brace 52 is mounted to the chassis 14 to support the pull rod 34. The pull rod brace has upper and lower members 54,56 in the form of two legs joined at a corner 58 (see FIGS. 9A and 9B). A wall 60 is formed between the upper and lower members along one leg thereof. The space 62 between the other legs of the upper and lower members is left open, for a purpose to be described further below. An opening 64 defined by a cylindrical collar 66 extending from the wall 60 is formed to accommodate the pull rod 34. The interior surface of the collar 66 is lined by a bearing 68, which may be made from any suitable bearing material, to ease movement of the pull rod 34 therethrough and provide additional support for the pull rod. The pull rod brace 52 is fastened to the chassis 14 by, for example, inserting screws 70,72,74 through openings 76,78,80 at the ends and the corner 58 of the brace. The openings 76,78,80 may be formed as alternating half cylinders, as shown in FIGS. 7, 9A, and 9B, to allow the brace to be more readily molded as a single piece. A compression spring 82 is provided around the pull rod 34 between the end of the cylindrical collar 66 and the wall 36 of the pump mechanism support 16. The spring 82 biases the pump mechanism support 16 away from the pull rod brace 52, which aids in maintaining the retraction mechanism in the engaged position, described further below. Any other suitable biassing mechanism may be provided. The toggle linkage 32 comprising a pair of toggle links 84,86 and a connecting link 88 is rotatably attached to the pull rod brace 52 at the end thereof and to the long end piece 44 of the support arm 38. Preferably, each toggle link is formed identically, as shown in FIG. 10, to reduce the tooling. Referring to FIG. 10, each toggle link has a single arm 90, with a hole 92 formed at the end, and a pair of arms 94,96 forming a fork, also with holes 98,100 formed in alignment at the ends thereof. The connecting link 88 also includes a forked end 102 comprising a pair of arms having aligned holes therethrough. The connecting link 88 is inserted through the slot 46 in the main arm 40 of the support arm 38. A widened portion 104 of the slot 46 is provided to slip the forked end 102 through during assembly. The single arm 90 of a first 84 of the two toggle links is inserted between the pair of arms of the forked end 102 of the connecting link 88 with the holes aligned. The nested single arm and forked end are further inserted between the pair of arms of the forked end of the second 86 of the two toggle links, also with the holes aligned. A toggle pin 106 is inserted through the aligned holes and held in place by a clip 108 on both ends. The two toggle links 84,86 and the connecting link 88 are, in this manner, rotatably joined about an axis A defined by the aligned holes and the toggle pin 106. The holes in the pair of arms of the first toggle link 84 are aligned with the opening 80 at the end of the pull rod brace 52, and the first toggle link 84 is fastened to the pull rod brace, as by the screw 74 noted above, for rotation about an axis B defined by the aligned holes and the screw 74. The single arm of the second toggle link 86 is inserted in the slot 46 of the long end piece 44 of the support arm 38. A hole in the long end piece 44 is aligned with the hole in the single arm. A toggle pin 108 is inserted through the holes and fastened with clips. The second toggle link 86 is thereby fastened to the support arm 38 for rotation about an axis C defined by the aligned holes and the toggle pin 108. In the retracted position, the two toggle links 84,86 are aligned along a straight line defined by alignment of the axes A, B, and C on a line in a plane perpendicular to the axes, as shown in FIGS. 1, 2, 5, 7, and 8. The straight line alignment also aids in maintaining the retraction mechanism 10 in the retracted position. Referring to FIGS. 3 and 4, to engage the pumping mechanism assembly with a cassette, the connecting link 88 is pushed toward the pull rod 34 (described further below). This causes the toggle links 84,86 to rotate about the axis A. The axis A moves toward the pull rod 34. The first toggle link 84 rotates about the axis B, and the second toggle link 86 rotates about the axis C. Also, the axis C moves toward the holster 18, drawing the support arm 38 in a direction toward the holster 18 as well, indicated by the arrow 30. The support arm 38, being connected to the pull rod 34, causes the pull rod to move in a parallel direction toward the holster 18. In this manner, the pumping mechanism assembly support 16, connected to the pull rod 34, is caused to move in the direction of the arrow 30 toward the holster 18 in which the cassette may be mounted. The pumping mechanism assembly on the pumping mechanism assembly support 16 thereby engages the cassette in the holster 18. The connecting link 88 is attached to the retraction assembly 22. The retraction assembly includes a retraction link 110 which is mounted for rotation on the retraction shaft 28 in a retraction brace 112. The retraction brace 112 is fastened to the chassis 14 in any suitable manner, such as by screws 114,116. Referring to FIGS. 11A and 11B, the retraction link 110 has a cylindrical member 118 having an opening 120 therethrough sized to accommodate the retraction shaft 28. The retraction shaft may be fixed within the cylindrical member in any suitable manner, such as by providing a screw 122 through a threaded hole 124 in the cylindrical member 118 and retraction shaft 28. Accordingly, upon rotation of the retraction shaft 28, the retraction link 110 also rotates. The cylindrical member 118 of the retraction link 110 also has an upper stop 126 and a lower stop 128, discussed more particularly below, formed by a half cylinder cut-away portion, as shown more particularly in FIGS. 11A and 11B. The retraction link 110 also has an extension 130 to which the connecting link 88 is rotatably attached in any suitable manner. For example, the connecting link may include a second forked end 132 having holes therein which align with a hole 134 in the extension. A pin or other fastener (not shown) inserted through the aligned holes thereby attaches the connecting link 88 to the retraction link 110. When the retraction link 110 is rotated about an axis defined by the retraction shaft 28, the connecting link 88 also rotates, causing the connecting link 88 to translate in a direction orthogonal to the retraction shaft axis. The retraction shaft 28 and retraction link 110 are mounted within the retraction brace 112. The retraction brace has a pair of opposed walls 136,138, as shown in FIG. 12. Aligned openings 140,142 to accommodate the retraction shaft are formed in the opposed walls. A compression spring 144 around the retraction shaft 28 is provided between an outer surface of one 136 of the opposed walls and a clip 146 fastened to the retraction shaft 28. The spring 144 biases the shaft 28 in the direction of arrow 30 toward the holster 18, thereby tending to retain the retraction mechanism 10 in the engaged position (shown in FIGS. 3 and 4). A switch 148 is located at the end of the retraction shaft 28, in contact therewith when the retraction shaft is in the engaged position. When the retraction shaft 28 is pulled against the biassing force to retract the mechanism, discussed further below, contact with the switch 148 is broken, causing a signal that the pumping mechanism assembly is retracted to be communicated to, for example, a system controller (not shown). Other suitable biassing mechanisms and switch assemblies may be used. The retraction link 110 fits in the space between the opposed walls 136,138 of the retraction brace 112. As shown more particularly in FIG. 12, one 136 of the opposed walls includes three shoulders formed therein to provide stops: an engaged position stop 150, a retracted position stop 152, and an overrotation stop 154. The engaged position stop 150 is oriented to abut the upper stop 126 of the retraction link 110 in the engaged position. The engaged position stop 150 is offset from the retracted position stop 152 along a line parallel to the axis of the retraction shaft 28. Accordingly, the retraction shaft 28 must be pulled against the force of the biassing spring 144 to move the stops 126,150 out of abutment. Once the upper stop 126 and the engaged stop 150 are no longer abutting, the retraction shaft 28 can be rotated. The retracted position stop 152 lies in a plane parallel to the axis of the retraction shaft 28. Upon rotation of the shaft, counterclockwise in FIGS. 1, 4, and 5, the upper stop 126 of the retraction link 110 abuts against the stop 152. The stop 152 is oriented at an angle chosen to prevent rotation of the retraction shaft 28 beyond the position at which the pump mechanism engages the cassette. An interior face 156 of the wall 136 of the brace 112, adjacent to and oriented orthogonally to the retracted position stop 152, abuts against the outer half-cylinder end surface 158 (FIG. 11B) to aid in retaining the shaft 28 against the biassing force of the spring 144 to lock the shaft in the rotated position. To return to the engaged position, the shaft 28 is rotated in the opposite direction, clockwise in FIGS. 1, 4, and 5, until the upper stop 126 passes the interior face 156 of the brace 112. Once past the interior face 156, the biassing force provided by the spring 144 pulls the retraction shaft 28 back into the engaged position with the upper stop 126 abutting the engaged position stop 150. In this manner, the retraction mechanism 10 tends to remain in the engaged position, thereby minimizing the likelihood of free flow of fluid on the flow path. The overrotation stop 154 also lies in a plane parallel to the axis of the retraction shaft 28. Upon rotation of the shaft 28 back to the engaged position, the lower stop 128 of the retraction link 110 abuts against the overrotation stop 154. The overrotation stop 154 is oriented at an angle to prevent the rotation of the retraction shaft 28 beyond the position at which it is necessary to engage the pumping mechanism assembly with the cassette. Accordingly, the overrotation stop 154 further ensures that the retraction shaft 28 returns to the engaged position. It will be appreciated that other suitable locking mechanisms to retain the retraction assembly in the engaged position or the retracted position or to prevent overrotation may be provided. The retraction mechanism 10 is relatively compact and takes up a minimal amount of space inside the infusion system housing 26. The mechanism can be held in place by a top strap 160 (FIG. 5) fastened with the three screws 70,72,74 through the pull rod brace 52 and the two screws 114,116 through the retraction brace 112. If desired, one of the screws can be an adjustable screw, incorporating some play to accommodate any adjustments needed, for example, because of variations in parts between molding lots. The handle 24 is attached in any suitable manner to the retraction shaft 28. The handle extends outside of the housing 26 of the infusion system, opposite the side in which the cassette is mounted, to be accessible to a user. Suitable markings indicating the engaged, or cassette locked, position and the retracted, or cassette unlocked, position may be provided on the housing 26 to direct the user in the correct rotation of the handle. The handle 24 may be formed in any suitable shape, such as a narrow wedge, and oriented to point generally upwardly in the engaged position. To retract the pumping mechanism assembly and disengage the cassette, a user pulls out on the handle, away from the cassette, and rotates the handle in a counterclockwise direction, or "downward," as indicated on FIGS. 1, 4, and 5. This orientation and motion is more intuitive for the user. Also, the first pulling step ensures that the handle will not be accidentally rotated into the retracted position, to prevent unintended free flow of fluids through the cassette. The retraction mechanism has been described in relation to a pumping system incorporating a flow path and pumping and valve chambers on a cassette. However, the mechanism is applicable to other types of infusion systems in which the described rotary to linear motion can be employed to engage and retract a mechanism. For example, the mechanism can be used to engage and retract the pumping mechanism of a peristaltic pump. Similarly, the mechanism is not limited to systems which employ cassettes or other removable or disposable devices. The invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.	A retraction mechanism is disclosed for retracting and engaging the pumping mechanism assembly of an infusion pump with an infusate flow path. The retraction mechanism provides a linkage which converts rotary motion of a handle about an axis to linear motion along a line parallel to the axis. The linkage is connected to the pumping mechanism assembly to cause the pumping mechanism assembly to retract from or engage with the flow path via a disposable cassette. The retraction mechanism is biassed toward the engaged position to prevent free flow of infusates on the flow path. The retraction mechanism is operable in two steps: first, the handle is pulled out against the biassing force; second, the handle is rotated until it locks into the retracted position. The mechanism includes a toggle linkage which aids in locking the mechanism in the retracted position and in biassing the mechanism to the engaged position when the handle is moved out of the locked retraction position.	0
CROSS-REFERENCES TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 61/566,673, filed Dec. 4, 2011. Each application is incorporated herein by reference in entirety. FIELD OF THE INVENTION The present invention is generally directed toward an asphalt composition containing ground tire rubber, hereinafter referred to as “GTR”. In a second aspect, the present invention is directed to methods for producing a modified asphalt containing ground tire rubber. BACKGROUND OF THE INVENTION Asphalt blended with ground tire rubber (also known as crumb rubber, or recycled tire rubber) has been used extensively and has been previously described. The addition of the rubber to asphalt allows for improved performance of roads or other paved surfaces due to resistance to rutting, cracking and deformation. Furthermore, the addition of ground tire rubber can reduce road noise. Not only does the rubber improve the performance of the asphalt, it allows old tires to be recycled into a useful substance instead of piling up in tire dumps. However, the previously known methods of blending GTR with asphalt suffered from a problem with the settling of rubber particles out of the blend. As a result, the GTR was not sufficiently distributed within the asphalt composition, thus requiring continuous agitation. The currently disclosed invention, however, provides for a method of suspending GTR in an asphalt composition such that settling of the GTR is reduced or eliminated for a period of at least 48 hours following agitation. SUMMARY OF THE INVENTION An improved method for suspending GTR in asphalt is disclosed. The method allows GTR to be used without the GTR particles settling out of the asphalt blend. The GTR will remain suspended in the asphalt and will not settle for at least 48 hours in the absence of mechanical agitation. In a second aspect, an asphalt composition containing ground rubber is disclosed. In a third aspect of the invention, a pavement structure containing GTR is disclosed. DETAILED DESCRIPTION The following detailed description is presented to enable any person skilled in the art to make and use the invention. For purposes of explanation, specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein. The methods disclosed herein allow one to produce an asphalt composition that contains a stabilized GTR content. The process comprises the following steps. First, the GTR is blended with an asphalt bitumen at a high temperature, preferably in a blender that includes an agitator and heating coils. Although any size of GTR particles may be used, in a preferred embodiment, 40 mesh GTR is used. It should be appreciated that finer ground tire rubber particle sizes may also be used. Using the methods disclosed herein, concentrations of GTR can be increased such that even at 20% GTR by weight, the GTR does not settle out. It is possible that even larger quantities of GTR may be added, but resulting composition becomes very viscous and difficult to handle. Any grade of asphalt that would be used for a paving application could be used in the composition. The asphalt is added to the blend unit such that the heating coils are covered with asphalt. The temperature of the asphalt should be sufficiently high to allow it to be blended with the GTR, or approximately 300 to 400 degrees Fahrenheit, but preferably in the range of 350 to 380 degrees Fahrenheit. Next, a GTR stabilizer is added in amounts from 0.1% to 10% by weight of the GTR and asphalt blend. In a preferred embodiment, between 1% and 3% by weight of the GTR and asphalt blend is used. The stabilizer may be any chemical composition that allows the GTR particles to remain suspended in the blend. Although the GTR stabilizer may stabilize the GTR using any means, one such mechanism of operation is by creating a shear thinning (thixotropic) media that would prevent or slow down the settling of GTR in the absence of shear, due to its high viscosity. Alternatively, the GTR stabilizer could help anchor the GTR particles in the asphalt media similar to how a micelle is anchored in the water phase of an emulsion. Although any commercially available GTR stabilizer may be used, in a preferred embodiment, the GTR stabilizer is KOMAXX brand stabilizer available from Starbinder, defined as a composition comprising a blend of oil, approximately 5-15% diethylenetriamine (DETA), and sodium hydroxide, wherein a 1% solution in water has a pH of 11. The GTR stabilizer is added and allowed to react under agitation. In one embodiment, this reaction may require 2 to 4 hours, but, of course, factors such as quantity of components, temperature, viscosity, and agitation speed will affect the reaction time. The efficiency of the reaction may also be improved by the addition of chemical promoters or catalysts. Once the GTR has been stabilized, the asphalt composition containing the GTR may be used to create a pavement using traditional paving techniques. Working Embodiments. EXAMPLE 1 GTR and paving grade asphalt are blended at high temperature (300 to 400° F., preferably 350 to 380° F.). To the resulting blend, GTR stabilizer is added and allowed to react under agitation, typically 3 to 4 hours. At the end of this period the GTR material is stabilized. The amount of stabilizer added varies from 1.5% to 2.5% by weight of the GTR and Asphalt blend. In some cases, depending on the chemical composition of the base asphalt used, there is a pre-treatment step before the stabilizer is added. This step consists of a chemical promoter with the purpose of increasing the speed and efficiency of the stabilization reaction. PG 67-22 asphalt was added to the blend unit such that the coils are covered with asphalt. In this embodiment, 81,880 pounds of asphalt were used. Next, the blend unit agitator is turned on and heated to 355 degrees +/−5 degrees Fahrenheit. Once asphalt is at 355.degree. F. +/−5 degrees, 8,280 pounds of GTR (Liberty 40 Mesh) is added to the asphalt. The mixture is then blended at 355.degree. F. +/−5 degrees for 3 hours. After 3 hours of mixing, 1,840 pounds of Komaxx, comprising a blend of oil, approximately 5-15% diethylenetriamine (DETA), and sodium hydroxide, wherein a 1% solution in water has a pH of 11 , is added (2.0% by weight). After the Komaxx has been added, the mixture is blended at 355.degree. F. +/−5degrees for 3hours. Finally, the samples are pulled. An analysis of the mixtures shows that all of the GTR remains stable in the mixture and does not settle out when analyzed according to ASTM 7173, herein incorporated by reference. This is verified by obtaining 4.degree. F. or less of difference between the ring and ball softening point of the top and bottom samples of the test tube as conducted according to ASTM 7173. The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. It will be apparent to one of ordinary skill in the art that methods, devices, device elements, materials, procedures and techniques other than those specifically described herein can be applied to the practice of the invention as broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of methods, devices, device elements, materials, procedures and techniques described herein are intended to be encompassed by this invention. Whenever a range is disclosed, all subranges and individual values are intended to be encompassed. This invention is not to be limited by the embodiments disclosed, including any shown in the drawings or exemplified in the specification, which are given by way of example and not of limitation. While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. All references throughout this application, for example patent documents including issued or granted patents or equivalents, patent application publications, and non-patent literature documents or other source material, are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in the present application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference).	We disclose a method of making an asphalt composition containing large quantities of ground tire rubber. Over 20% GTR by weight can be used in the asphalt composition without the GTR settling out. The method comprises a series of heating and blending and using a GTR stabilizer.	2
CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application No. 61/900,950 filed Nov. 6, 2013, the disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates generally to transmissions, and more particularly to shift controls for manually shifted transmissions. BACKGROUND OF THE INVENTION [0003] Transmissions, such as those widely used in vehicles, are well know in the art. Transmissions, also known as gearboxes, typically include a case or housing containing an input shaft, an output shaft, and a plurality of meshing gears. The meshing gears contained within the transmission case are of varying size to provide a plurality of gear ratios. By appropriately shifting among these various gear ratios, acceleration and deceleration of the vehicle can be accomplished in a smooth and efficient manner. [0004] Manually shifted vehicle transmissions, that is, those in which gear engagement is shifted in response to some physical exertion by an operator, are well known and are often preferred various types of vehicles, such as heavy duty trucks and racing or competition vehicles. Many transmission structures are known for manually shifting among the various gear ratios. In a conventional manual transmission, the driver moves an upper portion of a pivotable shift lever to effect shifting of the gears. In response thereto, a lower portion of the shift lever engages and moves one or more shift rails provided within the transmission. Shift rails are typically supported within the transmission case for sliding movement from a central or neutral position forward to one gear set engaging position or rearward to another gear set engaging position. Shift forks attached to a shift rail engage collars connected to various clutches to connect and disconnect the gear sets with various shafts. The initial selection and subsequent movement of a shift rail causes certain sets of gears to be connected between the input shaft and the output shaft to provide a desired output gear ratio. [0005] Typically, manually shifted transmission gear ratio positions are arranged in pairs of shift rail movement paths, with movement of the shift rail forward or backward out of a neutral position effective to engage one set of gears. For example, in a typical six speed transmission, the first and second gear ratios are located in a first path, the third and fourth gear ratios are located in a second path, and the fifth and sixth gear ratios are located in a third path. A reverse gear may be located on a separate path or on a path along with another forward ratio. For example, in a five forward speed transmission, the reverse gear may be located on the same path as that used to engage the first or fifth gear sets. [0006] Human error may be introduced during manual shifting of the shift lever. A common problem is shifting a transmission to an unintended gear, such as shifting into a reverse gear when a forward gear is intended. This could lead to disastrous results. Several types of reverse gear lockout safety systems have been developed to alleviate such problems. [0007] Another problem is downshifting into an unintended gear. Downshifting is common in racing or competition vehicles to maximize vehicle performance. For example, downshifting from fourth gear to third gear would be common to slow the vehicle for a turn and put the vehicle in a better gear for acceleration when the vehicle comes out of the turn. However, it is possible that the driver may mistakenly downshift the transmission by moving the shift lever into an undesired path of movement. This is not uncommon in racing or competition vehicles because of the intensity of the racing event. Such inadvertent downshifting may result in undesirable consequences. For example, downshifting from fourth gear to first gear (instead of third gear) would cause the vehicle engine to unacceptably increase engine speed, possibly causing damage to the engine and to the vehicle's main friction clutch. SUMMARY OF THE INVENTION [0008] The present invention is a manually operable transmission, such as a transmission for racing or competition vehicles. The transmission includes standard components such as a housing, input and output shafts, and one or more shift rails that selectively clutch various gear sets having various gear ratios for driving engagement of the input and output shafts. A manually operable shift lever is pivotally mounted to drivingly engage a shift rail assembly to selectively effect engagement of the various gear sets. [0009] The transmission includes a blocking mechanism selectively movable between a blocked position wherein the shift lever is prevented from drivingly connecting a first forward gear set between the input shaft and the output shaft, and an unblocked position in which the shift lever is free to cause the first forward gear set to drivingly connect the input shaft and the output shaft. An electronic controller is provided for moving the blocking mechanism into the unblocked position. A manually operable release switch is provided to generate a signal to the electronic controller to move the blocking mechanism into the unblocked position when an intentional engagement of the first gear set is desired. Preferably, the release switch is a momentary release switch that operates a solenoid to allow the blocking mechanism to move into the unblocked position only for so long as the switch is activated. [0010] The transmission may also include a reverse gear inhibiting mechanism selectively movable between an inhibiting position inhibiting the shift lever from engaging a reverse gear set and an uninhibited position wherein the inhibiting mechanism allows the shift lever to engage the reverse gear set. A second solenoid may be provided to control, within limits, the reverse gear inhibiting mechanism. The same signal generated by the manually operable release switch may be used to simultaneously move the reverse gear inhibiting mechanism to an uninhibited position. [0011] Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIGS. 1A and 1B together are a cross-sectional view of a transmission in accordance with the present invention. [0013] FIG. 2 is a cross-sectional view of a portion of the transmission of FIGS. 1A and 1B taken along line 2 - 2 . [0014] FIG. 3 is a perspective view of the gate control of FIG. 2 . [0015] FIG. 4 is plan view of the guide plate of FIG. 2 . [0016] FIG. 5 is a partial cross-sectional view of the transmission of FIGS. 1A and 1B taken along line 5 - 5 . [0017] FIG. 6 is a view of the reverse shift rail of the transmission of FIGS. 1A and 1B . [0018] FIG. 7 is a partial cross-sectional view of the transmission of FIGS. 1A and 1B taken along line 7 - 7 . [0019] FIG. 8 is a schematic view of controls for the transmission of FIGS. 1A and 1B . DESCRIPTION OF PREFERRED EMBODIMENTS [0020] Referring to FIG. 1A and 1B , a transmission 10 is, in large measure, a conventional manually shifted vehicular transmission adapted to provide several forward gear ratios between an input shaft 12 at the forward end of the transmission and an output shaft 14 , as is well known in the art. The transmission 10 has a single countershaft 16 , six forward gear ratios and one reverse gear ratio, although the present invention may be applied to multi-countershaft transmissions, range boxes and nearly any number of gear ratios. Transmission housing 18 encases the various components of the transmission 10 . [0021] As is well known in the art, various gears may be selectively clutched to the output shaft 14 to drive the output shaft at various speed ratios relative to the input shaft speed. For example, first gear set 22 , 22 ′ and second gear set 24 , 24 ′ may be selectively clutched to output shaft 14 by clutch 26 . Third gear set 32 , 32 ′ and fourth gear set 34 , 34 ′ may be selectively clutched to output shaft 14 by clutch 36 . Fifth gear set 42 , 42 ′ and sixth gear set 44 , 44 ′ may be selectively clutched to output shaft 14 by clutch 46 . Reverse gear set 52 , 52 ′, 52 ″ (idler gear 52 ″ shown out of position for illustrative purposes) may be selectively clutched to output shaft 14 by clutch 56 . The various clutches are drivingly connected to the shift rail assembly 70 by shift forks, as is well known in the art. [0022] Transmission 10 may be manually shifted among the various gear ratios through manual shift lever 60 mounted on shift lever housing 62 . The shift lever 60 may pivot forward 60 a and backward 60 b (as viewed in FIGS. 1A and 1B ) as well as transversely about a pivot pin 64 . The lower end of the shift lever 60 is formed with a finger 66 that drivingly engages a shift rail assembly 70 . The shift rail assembly 70 includes a rear shift rail 72 having an aperture 74 for receiving the shift lever finger 66 . The shift rail assembly 70 also includes a forward shift rail 76 drivingly connected to the rear shift rail 72 by pins 78 which extend through a gate member 80 . Shift rail 72 includes a reverse paddle 75 , the purpose of which will be explained later. [0023] As is well known in the art, transverse movement of the shift lever 60 about the pivot pin 64 causes rotation of the shift rail assembly 70 about rotational axis 71 to select pairs of gear sets that can be engaged. Forward and backward pivoting of the shift lever 60 moves the shift rail assembly 70 axially along axis 71 to cause engagement of one of the pairs of selected gear sets with the output shaft 14 . A spring and detent system 82 provides operator feel for the forward, neutral and rearward positions of the shift rail assembly 70 . [0024] Selection of pairs of gear sets to engage the output shaft 14 is made through the gate 80 . Referring to FIGS. 2 , 3 and 4 , the gate 80 includes a selector finger 82 that travels within a guide plate 90 . The gate 80 may be cast, machined or formed from powdered metal. Guide plate 90 is secured to the transmission housing 18 by bolts (not shown). A cover plate 84 is bolted to the housing 18 for assembly purposes and to provide access to the gate 80 . When the shift lever 60 is in a neutral position in which no gear set is engaged with the output shaft, selector finger 82 is in the neutral track 92 of the guide plate 90 . In this position, transverse movement of the shift lever 60 causes the selector finger 82 to pivot between various guide plate tracks 91 , 93 , 95 , 97 . [0025] The guide plate tracks limit rotation of the shift rail assembly 70 when the shift lever 60 is in a forward or backward position corresponding to engagement of a gear set. The guide plate tracks correspond to rotational positions of the shift rail assembly 70 . Guide plate track 97 corresponds to forward gear set pairs for first and second gears (i.e. gear ratios); guide plate track 95 corresponds to forward gear set pairs for third and fourth gears; guide plate track 93 corresponds to forward gear set pairs for fifth and sixth gears; guide plate track 91 corresponds to the reverse gear set. [0026] Referring to FIGS. 1 and 5 , a selector finger 100 is rigidly attached to the forward shift rail 76 . Rotation of the shift rail 76 causes the finger 100 to select a forward gear set pair lever 102 , 104 or 106 or reverse gear lever 108 for driving engagement with the shift lever assembly 70 . When a forward gear pair lever 102 , 104 , or 106 is selected, the shift rail assembly 70 will be drivingly engaged with the clutch collars and shift forks of the respective forward gear sets. Forward and backward pivotal movement of the shift lever 60 will force backward and forward movement of the shift rail assembly 70 causing clutching of one of the forward gears sets of the selected pair with the output shaft 14 . [0027] Referring also to FIG. 6 , a separate shift rail assembly 110 is provided to engage the fifth and sixth gear sets and the reverse gear set. When selector finger 100 is engaged with the lever 106 , axial movement of the shift lever 60 causes axial movement of the shift rail 105 and shift fork 116 , and engagement of the fifth or sixth gear sets with output shaft 14 . When selector finger 100 engages the reverse lever 108 , axial movement of the shift lever 60 causes axial movement of the shift rail 110 and shift fork 118 , and engagement of the reverse gear set with output shaft 14 . Forward Gate Control [0028] Referring again to FIGS. 2 and 3 , gate 80 is rigidly connected to shift rail assembly rails 72 and 76 by pins 78 for rotational and axial movement in response to shift lever 60 movements. Rotational movement of the gate 80 aligns the shift finger 82 for axial travel in one of the gear guide tracks 91 , 93 , 95 , or 97 . Gate 80 includes an integral cam track 86 . A centering mechanism in the form of a ball and spring detent mechanism 88 is threaded into the housing 18 , with the ball 89 engaging the cam track 86 under a spring load. The cam track 86 has a neutral position 87 that provides feel to the shift lever 60 at the neutral track 92 of the guide plate 90 . [0029] A track block extension 130 is integrally formed on the gate 80 opposite the cam track 86 . A twelve volt gate control solenoid 120 is threaded into housing 18 opposite the detent mechanism 88 . The solenoid includes a pin 122 that is retractable when power is applied to the solenoid, as is well known in the art. A spring 124 forces the pin 122 to its fully extended position as shown in FIG. 2 when power is not applied to the solenoid. [0030] The track block 130 includes a blocking surface 132 for selective engagement with the solenoid pin 122 . The solenoid pin 122 and blocking surface 132 are oriented such that the selector finger 80 cannot be rotated to the first and second gear set track 97 unless the pin 122 is retracted, that is, unless power is applied to the solenoid. The blocking extension 130 has an undercut surface 136 adjacent to blocking surface 132 . The pin 122 cannot engage the undercut surface 136 when fully extended, thereby permitting free movement of the selector finger among track guide tracks 91 , 93 , and 95 . The solenoid 120 is designed such that the pin 122 has sufficient strength to carry the side load which will be applied by the selector 80 through the blocking surface 132 . A twelve volt solenoid can be used, but other sizes and voltages may be used. [0031] In operation of the transmission, the operator must apply power to the solenoid 120 in order to access the first pair of gear sets. The first pair of gear sets includes the first gear set 22 , 22 ′ and the second gear set 24 , 24 ′, which provide the lowest output shaft speed ratios. This pair of gear sets is typically engaged for the initial launch of a vehicle. If the first forward gear set 22 , 22 ′ is engaged, a shift to the second forward gear set 24 , 24 ′ will be possible without powering the solenoid because the solenoid pin 122 will be restricted from extending by slide surface 134 on the track block extension. [0032] When the transmission is shifted from the second forward gear set 24 , 24 ′ to the third forward gear set 32 , 32 ′ or fourth forward gear set 34 , 34 ′, the selector finger 82 will move to gate track 95 with minimal resistance from the solenoid pin 122 as it slides along the slide surface 134 . However, when the selector finger 82 reaches the gear set track 95 , the blocking surface 132 will have already passed the pin 122 , allowing the pin to extend fully under the force of solenoid spring 124 . [0033] After the selector finger 82 is moved from the guide track 97 , the gate 80 will prevent the transmission operator from returning the selector finger 82 to guide track 97 because the gate 80 will be blocked by the pin 122 engaging the blocking surface 132 . Of course, activating the solenoid will retract the pin 122 , thereby allowing the selector finger 82 access to the track 97 ultimately access to the associated forward gear sets. Reverse Inhibiting Mechanism [0034] As previously explained, reverse gear set 52 can be clutched to the output shaft 18 through the output clutch 56 . To position the shift lever 60 so that the gate control 80 is in the reverse guide track 91 ( FIG. 2 ), selector finger 100 must engage the reverse lever 108 . A reverse inhibiting mechanism 140 prevents inadvertent access to the reverse gear guide track 97 . [0035] Referring to FIG. 7 , mechanism 140 includes a plunger 142 seated in a cylindrical opening 19 in the housing 18 . The plunger has a forward surface 141 and an integral annular flange 150 which is sized to allow a close fit in the opening 19 . When the plunger 142 is in an extended position, the forward surface 141 will engage the reverse paddle 75 and block the reverse paddle 75 from rotating to an extreme position, thereby blocking the selector finger 80 from entering guide track 91 . Plunger 142 is biased into the blocking position shown in FIG. 7 by biasing spring 144 . [0036] A collar 146 surrounds the plunger 142 . A spring 150 is positioned to react against the collar 146 and the plunger flange 150 . The spring 150 biases the collar 148 axially away from the plunger flange 150 . When the plunger 140 is in an uninhibited position, the spring 144 will bias the plunger to block the reverse paddle from a position for engaging the reverse gear set. In this configuration, the shift lever 60 easily will be able to overcome the force of spring 144 to move the plunger from the blocking position to allow access the reverse shift rail 110 . [0037] A reverse inhibitor solenoid 160 is threaded into the housing 18 . Reverse inhibitor solenoid 160 has an extendible pin 162 . Reverse inhibitor solenoid 160 is a twelve volt solenoid identical to the gate control solenoid 120 ; however, the two solenoids do not have to be identical. The pin 162 is retractable when power is applied to the solenoid 160 . A solenoid spring 164 forces the pin 162 to its fully extended position as shown in FIG. 7 when no power is applied to the solenoid. When the reverse paddle 75 is not engaged with the plunger 142 , solenoid pin 162 is extended by the solenoid spring into the path of collar 146 . If the collar 146 is moved away from the reverse paddle 75 , the collar flange surface 147 will engage the pin 162 , thereby blocking the plunger from retracting unless the force of spring 148 is overcome. [0038] The intent of this design is that the spring force 148 will be sufficient to prevent an unintentional shift engaging the reverse gear set, but not an absolute restriction. For safety reasons, it is preferred that the transmission operator be capable of engaging the reverse gear set manually if this is truly intended by the operator, but such intention must be demonstrated by overcoming the force of spring 148 . The reverse inhibitor mechanism merely inhibits engagement of the reverse gear set, but does not absolutely prevent engagement. Controls [0039] The gate control solenoid 120 and reverse lockout solenoid 160 may be controlled simultaneously. For example, a switch may be used by a vehicle operator to momentary engage both solenoids simultaneously, thereby allowing engagement of the first pair of gear sets as well as the reverse gear set. The solenoids 102 and 160 are identical, but solenoids of different voltages or types may be used provided the controller 170 is adapted accordingly. Solenoids are commonly known and used and are readily available, such as Fema Corp. solenoid 51160. [0040] Referring to FIG. 8 , a thumb button switch 50 on a shift lever knob 61 may be used to send a signal to an electronic controller 170 to provide a simultaneous momentary signal to each of the solenoids 120 and 160 through appropriate wiring 162 , 164 connected to and powered by a vehicle electrical system. Of course, alternatively, separate switches also may be use to power the separate solenoids. [0041] This invention relates is particularly applicable to transmissions for completion or racing vehicles. The gate 80 limits the ability of a vehicle driver to downshift into the lower gear ratios without activating solenoid 120 which controls the blocking mechanism 80 . As such, the shift gate control between the first and second gear ratios is referred to a competition gate. The momentary release switch moves the solenoid pin 122 to its retracted position for a relatively short period of time, thereby allowing a driver to manually override the downshift limiting structure in a quick and easy manner for a relatively short period of time. [0042] The descriptions of specific embodiments of the invention herein are intended to be illustrative and not restrictive. The invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope as defined by the appended claims.	A manually shiftable transmission includes a blocking mechanism to prevent unintended engagement of a first forward gear set. An electronic controller is provided for moving the blocking mechanism into an unblocking position. A manually operable release switch is provided to generate a signal to an electronic controller to move the blocking mechanism into the unblocking position when an intentional engagement of the first gear set is desired. The transmission may also include a mechanism to inhibit engagement of a reverse gear set. The electronic controller and manually operable release switch may be used to move the reverse gear inhibiting mechanism to an uninhibited position.	5
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to certain fiberforming, melt-spinnable wholly aromatic copolyesters prepared from (a) 4-hydroxybenzoic acid, a hydroquinone, terephthalic acid and 4-hydroxy- or 4-carboxy-3'(4"-hydroxybenzoyl)benzophenone or from (b) a hydroquinone, terephthalic acid and 4-hydroxy- or 4-carboxy-3'(4"-hydroxybenzoyl)benzophenone. These copolyesters are useful for preparation of filaments having high break elongation and high modulus. They are also useful for extrusion molding or injection molding and for preparation of tough films. 2. Description of the Prior Art Aromatic copolyesters capable of forming optically anisotropic melts are well known in the art. These polymers have yielded heat-treated fibers with combinations of high modulus and low break elongation. These properties are especially useful in tire cords or drive belts. On the other hand there are uses such as in nonwovens or in fiber/plastic composites which would benefit from a combination of high modulus and high break elongation. The preparation of anisotropic fiber-forming, melt-spinnable polyesters yielding fibers with modulus above 140 dN/tex and with elongation above 9% is a worthwhile objective. Anisotropic melt polymers containing units derived from diketodiols are disclosed in U.S. Pat. Nos. 4,226,970 and 4,269,965 but the desired combination of high modulus and high break elongation is not disclosed in these references. It is believed that differences in structure are responsible. SUMMARY OF THE INVENTION The present invention is directed to melt-spinnable copolyesters of fiber-forming molecular weight that exhibit optical anisotropy in the melt and consist essentially of (a) Units I, II, III and IV or (b) Units I, II and III, said units having the structural formulas: ##STR2## where X is selected from the group consisting of hydrogen, halo- (preferably chloro-) or lower alkyl (preferably methyl), or aryl (preferably phenyl); Y is selected from the group consisting of oxygen and carbonyl; and wherein said copolyesters consisting essentially of Units I, II, III and IV contain from about 10 to 15 mole % of Unit I, from about 10 to 20 mole % of Unit II, from about 10 to 15 mole % of Unit III and from about 50 to 70 mole % of Unit IV; and wherein said copolyesters consisting essentially of Units I, II and III contain from about 40 to 45 mole % of Unit I, from about 40 to 50 mole % of Unit II and from about 10 to 15 mole % of Unit III. In each case the number of dioxy units in the copolyester is substantially equal to the number of dicarbonyl units. One group of preferred copolyesters of the invention consists essentially of Units I, II, III and IV where in Unit I, X is hydrogen or chloro-. Other preferred copolyesters of the invention consist essentially of Units I, II and III where in Unit I, X is chloro- or phenyl-. Melt-spun and heat-strengthened filaments of such polyesters as well as films and molded or extruded articles from such polyesters are included in the invention. DETAILED DESCRIPTION OF THE INVENTION Unit I in the copolyesters of the invention is 1,4-dioxyphenylene, lower alkyl-, halo-, or aryl-1,4-dioxyphenylene. Methyl and phenyl groups exemplify the preferred lower alkyl and aryl groups, respectively. Unit II is the terephthaloyl radical. Unit III is the oxy-1,4-phenylene-carbonyl-1,3-phenylene-carbonyl-1,4-phenylene-oxy radical or the oxy-1,4-phenylene-carbonyl-1,3 phenylene-carbonyl-1,4-phenylene-carbonyl radical. Unit IV is p-oxybenzoyl. The number of dioxy units present in the copolyester is substantially equal to the number of dicarbonyl units. Mole % is calculated on the basis of total moles of units present, i.e. [I+II+III+IV]. Suitable precursors for Unit I include hydroquinone or the corresponding substituted hydroquinones. This precursor is generally employed in the form of the diacetate. Terephthalic acid is a suitable precursor for Unit II while 4-hydroxybenzoic acid in the form of the monoacetate is useful for providing Unit IV. The diacetate of 4-hydroxy-3'(4"-hydroxybenzoyl)benzophenone or the monoacetate of 4-carboxy-3'(4"-hydroxybenzoyl)benzophenone can provide Unit III. J. Am. Chem. Soc. 60 pp 2283-2285 (October, 1938) discloses preparation of 4-hydroxy-3'(4"-hydroxybenzoyl)benzophenone. The monoacetate of 4-carboxy-3'(4"-hydroxybenzoyl)benzophenone is prepared as follows: 97.0 g (0.40 mole) of 3(4'-hydroxybenzoyl)benzoic acid was condensed with 37.0 g (0.40 mole) of toluene in a mixture of 200 g of HF and 95.0 g (1.40 moles) of BF 3 in a 1 liter Hastalloy® C shaker tube with agitation for 18 hours at 30° C. The reaction mixture was poured onto ice, the product collected, washed with water, suspended in water and neutralized with aqueous ammonia to a pH of 7-8, collected again, dried, and recrystallized twice from ethanol/water (1/1 by volume) by dissolving in ethanol, filtering, then diluting with water to provide 3(4"-hydroxybenzoyl)4'-methylbenzophenone. Melting point is 175.5°-176° C. Calculated for C 21 H 16 O 3 : C, 79.7%; H, 5.10%. Found: C, 79.6%, H, 5.10%. 3(4"-Hydroxybenzoyl)4'-methylbenzophenone (79.0 g, 0.25 mole) was oxidized with 53 g (0.53 mole) chromic anhydride (CrO 3 ) in a mixture of acetic acid (500 ml), concentrated H 2 SO 4 (1.5 g) and acetic anhydride (178 g, 1.75 moles) in a flask equipped with stirrer, thermometer, condenser and portal for addition of ingredients. All ingredients except CrO 3 were added, and the mixture stirred overnight, then at 60° C. again overnight, to ensure actylation of the phenolic group. The CrO 3 was added in increments of about 10 g such that with intermittent cooling a temperature of 50° C. was maintained. After subsequent addition of 200 ml more acetic acid and overnight stirring at ambient temperature, the reaction mixture was diluted to a total volume of 2 liters with ice and water, stirred, the product collected, washed with water and dried. Crystallization twice from acetic acid yielded 71% of 4-carboxy-3'(4"-acetoxybenzoyl)benzophenone, m.p., 241°-242° C. Calculated for C 23 H 16 O 6 : C, 71.1; H, 4.15. Found: C, 71.3; H, 4.31. The precursor reactants are generally combined in proportions corresponding to the molar proportions of the units desired in the copolyester products except that it is preferred to use a molar excess, indicated in the examples as (%) of the more volatile diacetate of hydroquinone, or substituted hydroquinone. Conventional polymerization techniques may be employed such as described in the aforementioned U.S. Pat. No. 4,118,372 and more particularly in the examples described below. In general, a mixture of monomers is heated with stirring, under nitrogen in a 250 ml 3-necked flask or polymerization tube in a Wood's metal bath or other suitable heating medium from approximately 250° C. to 330°-380° C. Polymerization is continued for up to a total of 0.5 to one hour or longer if necessary until a polymer of fiber-forming molecular weight is obtained. Usually a vacuum is applied to obtain a final product with high molecular weight. The copolyesters of the invention exhibit optical anisotropy in the melt as described in U.S. Pat. No. 4,118,372. FILAMENT PREPARATION The copolyesters of the invention are spun into filaments by conventional melt-spinning techniques without substantial degradation. In the examples below, filaments were prepared by melt-spinning into a quenching atmosphere of air or nitrogen and collected at a windup speed specified in the example. Melt pumping speed is adjusted to give the approximate linear density (D) shown in the tables at the stated windup rate. As used herein, the term "as-spun fiber" refers to a fiber which has not been drawn or heat treated after extrusion and normal windup. HEAT TREATMENT AND UTILITY Following collection, samples of undrawn (as-spun) monofilament were heat-treated in essentially relaxed condition in an oven as taught in Luise U.S. Pat. No. 4,183,895. Heating was in a purged nitrogen atmosphere with temperature increased in stages. Typically, temperature was raised from room temperature to 200° C. in 2 hours, then to 304° C. in another 7 hours, and finally maintained at 304° C. for an additional 7 to 16 hours. The final temperature, which is usually the maximum temperature, is critical for achieving maximum break elongation and high modulus. The flow temperature of the filaments is a function of thermal history and molecular weight. Crystallization and molecular weight growth during heat treatment can increase the flow temperature of the filaments, making possible heat treatment temperatures in excess of the original polymer flow temperature. The maximum temperature for optimum development of high break elongation and high modulus should be close to or above the initial flow temperature, preferably above the initial flow temperature. Higher molecular weights favorably affect the development of high break elongation. Higher spin stretch factors also favor the development of high break elongation (determined from orifice diameter and tex as-spun). The heat treated fibers of this invention are useful for a variety of applications such as in ropes or in nonwoven sheets, but it is believed they are most useful in reinforcement of plastic composites where the composite is expected to absorb a high amount of energy under stress before failure. TEST METHODS Inherent viscosity (n inh ), a measure of molecular weight, was computed from n inh =(ln n rel )/C where n rel is the relative viscosity and C is solution concentration in grams of polymer per deciliter of solvent. Relative viscosity is the ratio of polymer solution flow time to solvent flow time in a capillary viscometer at 30° C. The solvent employed was a mixture of 7.5% trifluoroacetic acid/17.5% methylene chloride/12.5% dichlorotetrafluoroacetone hydrate/12.5% perchloroethylene/50% p-chlorophenol (all percentages by volume). The concentration was 0.5 g polymer per deciliter of solvent. The polymers were characterized by polymer flow temperature, meaning the lowest temperature at which polymer was observed to be molten, showing flow properties and allowing fibers to be drawn from the melt. The filament flow temperatures were determined as in U.S. Pat. No. 4,183,895, Col. 11. Monofilament tensile properties were measured in accordance with A.S.T.M. 2101 Part 33 (1980) using a recording stress-strain analyzer at 70° F. (21.1° C.) and 65% relative humidity. Gauge length was 1.0 in (2.54 cm), and rate of elongation was 10%/min. Results are reported as D/T/E/M or T/E/M where D is linear density in tex units, T is breeak tenacity in dN/tex, E is elongation-at-break expressed as the percentage by which initial length increased, and M is initial tensile modulus in dN/text. Since linear density is normally substantially unchanged by heat-treatment, it is reported only for the as-spun filament. Average tensile properties for five filament samples are reported. EXAMPLES The same general procedure was used in all the examples. It should be understood that the results reported below are believed to be representative of what can be obtained and do not constitute all the runs performed involving the indicated reactants. Unfamiliarity with the reaction requirements of the system, use of impure reactants or inappropriate heat treatment conditions may cause other results such as lower elongation or modulus to be obtained. In the examples, the diacetate of the dihydric phenols and the monoacetate of the hydroxyacid was used. The terephthalic acid was used as such rather than as esters or other derivatives. In the examples below, the following code is employed to identify the polymerization reactants or functional equivalents as well as the repeat units provided by such reactants. HQ--hydroquinone CHQ--chlorohydroquinone PHQ--phenylhydroquinone TPA--terephthalic acid HBA--4-hydroxybenzoic acid DKDH--4-hydroxy-3'(4"-hydroxybenzoyl)benzophenone DKHA--4-carboxy-3'(4"-hydroxybenzoyl)benzophenone The monomer ingredients were added in substantially the same molar ratios as desired in the final polymer except that an excess (usually 4 to 7%) of acetylated dihydric phenol was generally used. The resultant polymer is identified, for example, as CHQ/TPA/DKDH/HBA (10/20/10/60) meaning it contained 10 mole % of chloro-1,4-dioxyphenylene units (from the diacetate of chlorohydroquinone), 20 mole % of terephthaloyl units (from terephthalic acid), etc. (excesses of diacetates are not included in these percentages). The 3-necked flask or polymer tube was fitted with: (1) a glass stirrer extending through a pressure-tight resin bushing, (2) a nitrogen inlet, and (3) a short column leading to a water- or air-cooled condenser with a flask for collecting acetic acid by-product. An attachment for application of vacuum was provided at the end of the condenser. An electrically heated Wood's metal bath or a boiling liquid vapor bath mounted for vertical adjustment was used for heating. The reaction mixture was heated to increasing temperatures with stirring at atmospheric pressure under nitrogen purge until essentially all the acetic acid had evolved. Then, vacuum was applied and pressure was reduced gradually from atmospheric to less than 1 mm of mercury (133.3 Pa). Heating under vacuum at less than 1 mm mercury pressure was then continued until viscosity had increased to a level believed satisfactory for melt-spinning. The cooled and solidified polymer was comminuted, and a portion was molded into a cylindrical plug for melt spinning. EXAMPLE 1 Filaments from Copolyesters having the Composition CHQ/TPA/DKDH/HBA (10/20/10/60) A polyester was prepared by heating the following ingredients in a 3-necked flask as described previously: ______________________________________81.0 g 4-acetoxybenzoic acid (.450 mole)18.0 g chlorohydroquinone diacetate (.0787-mole) (7% excess)30.75 g 4-hydroxy-3'(4"-hydroxybenzoyl) benzophenone diacetate (.0764 mole)24.9 g terephthalic acid (.150 mole)______________________________________ In the above mixture it is assumed that all of the excess acetate should be provided through the chlorohydroquinone because of its greater volatility and tendency to distill. The flask was heated from 200° to 330° C. in 32 min. Vacuum was then applied and the flask heated to 345° C. in 15 minutes. The resulting polymer softened at 270° C. and fibers could be pulled from a melt at 300° C. The inherent viscosity was 1.46. Polymer flow temperature as measured in the thermo optical test of Schaefgen U.S. Pat. No. 4,118,372 was 278° C. The polymer was spun through a five-hole spinneret with orifices 0.23 mm in diameter and 1.60 mm in length with cell temperature 304° C., spinneret temp 305° C. and wind-up speed 914 meters/min. [1000 ypm]. Properties of the as-spun filaments are shown in Table I along with properties of yarns heat-treated in a nitrogen atmosphere at various maximum temperatures. Yarns heated at a maximum 304° C. had high break elongation (14.4%) and high modulus (183 dN/tex). TABLE I______________________________________PROPERTIES OF FILAMENTS FROMCHQ/TPA/TKDH/HBA (10/20/10/60) Tex Initial per Tenacity Elongation ModulusTreatment Filament dN/tex at Break % dN/tex______________________________________As-spun 0.47 2.4 1.2 275Max. temp. 298° C. 0.47 3.3 8.7 208Max. temp. 304° C. 0.45 3.4 14.4 184Max. temp. 325° C. 0.42 3.4 4.1 183______________________________________ The polymer of this example may be melt extruded as film or molded with heat and pressure into various shaped articles. EXAMPLE 2 Repeating the Polymer of Example 1 with Higher Inherent Viscosity The polymerization of Example 1 was repeated using the same ingredients. The flask was heated from 200° to 330° C. in 30 minutes. Vacuum was then applied and heating was continued to 345° C. in 53 minutes. The inherent viscosity was 2.07, which is higher than in Example I. The polymer was melt spun through a five-hole spinneret having orifices 0.36 mm in diameter and 0.23 mm in length with cell temperature 367° C. and spinneret temperature 371° C. and a wind-up speed 183 m/min. Properties of the as-spun filaments are shown in Table 2. Properties after various maximum heat treatment temperatures are shown. Elongations above 9% at break were obtained for all heat treatments with maximum temperature in the range 290°-310° C. Initial moduli for these filaments were 144 to 212 dN/tex. TABLE 2______________________________________PROPERTIES OF FILAMENTS FROMCHQ/TPA/TKDH/HBA (10/20/10/60) SPUNFROM POLYMER WITH INHERENT VISCOSITY 2.07 Tex Initial per Tenacity Elongation ModulusTreatment Filament dN/tex at Break % dN/tex______________________________________As-spun 1.3 3.1 1.6 244Max. heat-treatment290° C. 1.2 4.2 11.3 144298° C. 1.3 4.0 27.6 212310° C. 1.3 3.6 14.8 192315° C. 1.2 3.6 7.6 203______________________________________ EXAMPLE 3 Filaments from Copolyester having the Composition HQ/TPA/DKDH/HBA (10/20/10/60) A polyester was prepared by heating the following ingredients in a polymer tube as described earlier: ______________________________________21.6 g 4-acetoxybenzoic acid (.120 mole)8.2 g 4-hydroxy-3'(4"-hydroxybenzoyl) benzophenone diacetate (.0204 mole) (7.1% excess)4.07 g hydroquinone diacetate (.0210 mole)6.64 g terephthalic acid (.0400 mole)______________________________________ The tube was heated from 284° C. to 346° C. in 44 minutes. Vacuum was applied for another 40 minutes at 346°-360° C. Fibers could be pulled from the melt at 354° C. Inherent viscosity was 1.43. The polymer was optically anisotropic in the melt. A filament was melt spun from a one-hole spinneret with a hole diameter of 0.23 mm with a cell temperature of 358° C. at a wind-up speed of 549 m/min. As-spun properties and properties after heat-treatment are shown in Table 3. This polymer having hydroquinone in place of the chlorohydroquinone of Examples 1 and 2 still provided heat-treated fibers with high break elongation and modulus. TABLE 3______________________________________PROPERTIES OF FILAMENTS FROMHQ/TPA/DKDH/HBA (10/20/10/60) Tex Initial per Tenacity Elongation ModulusTreatment Filament dN/tex at Break % dN/tex______________________________________As-spun 0.71 1.2 0.8 46Heat treated: 0.99 3.7 15.0 177 25-200° C., 2 hr.200-306° C., 7 hr. 304° C., 7 hr.Heat treated: 0.79 3.8 11.6 198 25-235° C., 2 hr.235-270° C., 2 hr.235-270° C., 2 hr.270-305° C., 2 hr.305-320° C., 16 hr.______________________________________ EXAMPLE 4 Filaments from Copolyester having the Composition PHQ/TPA/DKDH (40/50/10) The following ingredients were charged to a polymer tube: ______________________________________22.5 g phenylhydroquinone diacetate (.0832 mole) (4.5% excess)8.2 g 4-hydroxy-3'(4"-hydroxybenzoyl) benzophenone diacetate (.0204 mole)16.6 g terephthalic acid (.100 mole)______________________________________ The tube was heated from 210° to 350° C. in 28 minutes. Vacuum was then applied and temperature continued at 350° C. for 7 min. Fibers could be pulled from the melt at 330° C. The inherent viscosity was 1.20. A melt spun mono-filament was prepared from a spinneret having an orifice diameter of 0.23 mm with spinneret temperature at 260° C. and wind-up speed at 549 m/min. Properties of the resulting filament varied depending upon maximum heat-treatment temperatures. Highest break elongation (11.4%) was obtained with the maximum heat-treatment temperature at 277° C. as shown in Table 4. Heat treatment temperatures above and below 277° C. gave fibers with lower values. TABLE 4______________________________________PROPERTIES OF FILAMENTS FROMPHQ/TPA/DKDH (40/50/10) Tex Initial per Tenacity Elongation ModulusTreatment Filament dN/tex at Break % dN/tex______________________________________As-spun 0.51 2.9 3.3 166Max. heattreatment temp:292° C. 0.50 4.0 8.6 144286° C. 0.50 4.2 9.9 159277° C. 0.50 4.0 11.4 160267° C. 0.41 3.3 6.9 148260° C. 0.47 3.7 6.0 163258° C. 0.55 3.0 3.4 152______________________________________ EXAMPLE 5 Filaments from a Polyester having the Composition CHQ/TPA/DKHA/HBA (14/14/12/60) The following ingredients were heated in a polymer tube under a stream of dry nitrogen with stirring: ______________________________________5.65 g 4-carboxy-3'(4"-hydroxybenzoyl)- benzophenone acetate (.0145 mole)4.03 g chlorohydroquinone diacetate (.0176 mole) (4.8% excess)2.79 g terephthalic acid (.0168 mole)12.90 g 4-hydroxybenzoic acid acetate (.0716 mole)______________________________________ The tube was heated from 200° to 350° C. in 60 minutes; then vacuum was applied and heating was continued at 350° C. for 5 minutes. The polymer had an inherent viscosity of 1.91. Polymer flow temperature was 319° C. It was optically anisotropic in the melt. A molded plug was heated to 308° C. and melt spun through a spinneret orifice 0.23 mm in diameter at a temperature of 320° C. with a wind-up speed of 549 m/min. Properties of the fibers as-spun and after heat treatment are given in Table 5. TABLE 5______________________________________PROPERTIES OF FILAMENTS FROMCHQ/TPA/DKHA/HBA (14/14/12/60) Tex Initial per Tenacity Elongation ModulusTreatment Filament dN/tex at Break % dN/tex______________________________________As-spun 0.59 2.5 1.3 267Heat treated: 0.55 4.0 9.8 241200-275° C., 7 hrs. 275° C., 16 hrs.______________________________________ EXAMPLE 6 Filaments from Polyester having the Composition CHQ/TPA/DKHA (43/43/14) The following ingredients were heated in a polymer tube: ______________________________________5.49 g 4-carboxy-3'(4"-hydroxybenzoyl) benzophenone acetate (.0141 mole)10.32 g chlorohydroquinone diacetate (.0451 mole) (5% excess)7.14 g terephthalic acid (.0430 mole)______________________________________ The tube was heated from 210° to 340° C. in 65 min.; then vacuum was applied and heating was continued for 10 minutes at 340° C. The resulting fiber had an inherent viscosity of 1.32. The material was melt-spun at 325° C. with a wind-up speed of 549 m/min. using a single orifice 0.23 mm in diameter and 1.60 mm long. The preferred heat-treatment method was to increase the temperature progressively from 200° to 268° C. in 7 hours and then to heat at 268° C. for 16 hours in a purged nitrogen atmosphere. The fibers exhibited the following properties: ______________________________________ As-spun Heat-treated______________________________________Tex per filament 0.20 0.22Tenacity, dN/tex 2.0 3.4Elongation at break, % 1.5 13.7Initial Modulus, dN/tex 189 151______________________________________	Copolyesters useful for fibers having high elongation and modulus contain minor amounts of ##STR1## units where Y is oxygen or carbonyl.	3
This application is a continuation of application Ser. No. 08/545,708, filed Nov. 7, 1995, now abandoned, which is a 371 of PCT/SE94/00414 filed May 6, 1994. FIELD OF THE INVENTION The invention relates to a belt of the type used with an absorbent garment and, in particular, to a waist belt of flexible material comprising attachment means securely attached to the belt and located proximate one of the ends of said belt for securing said one end to an outer surface of said belt situated between the longitudinal edges thereof, said attachment means being of the hook element strip releasable type, and wherein said attachment means itself extends with its greatest dimension in the width direction of the belt. BACKGROUND OF THE INVENTION The type of belt in question can be integrated with an absorbent garment worn to assist in the collection of bodily discharges, particularly for persons suffering from incontinence, or the belt can be a separate belt to which an absorbent garment portion is attached by some means of releasable attachment such as hook and loop (also called touch and close) type fastening means, for instance such as sold under the trademark "VELCRO". The belt of the separate type can be either a disposable belt, for limited use with a small number of absorbent chassis garments and thus requiring no particular cleaning, or a more permanent type which may be washed many times before its effectiveness or appearance warrants a change to a new belt. Absorbent garments of the above mentioned type are well known in the art. WO-A-91/08725 discloses an example of both these types in conjunction with an absorbent garment. One of the problems recognized with such belts is achieving maximum comfort for the user by correct fitting, since incorrect fitting will result in sore, cut and/or painful areas for the user. One area where it has been found desirable to increase comfort is the area of the belt attachment to itself. When one examines WO-A-91/08725 for example, it is clear that the attachment of the hook element strip and the loop element strip together for fastening the belt can easily result in one of the edges of the hook strip projecting beyond the zone to which it is intended to be attached and, as a result, contacting the body. This contact with the body is particularly uncomfortable. Where the problem of incontinence is involved, it will be appreciated that persons suffering from this problem are often old and have physical handicaps of various types. As a consequence, they often require the assistance of personnel for fitting the belts or garments with integrated belts. If they, or the assistant personnel do not fasten the belt with great care, the hook element strips can easily be left in a position which makes them contact the body. This factor is particularly important for the case where the users are unable to assist themselves or otherwise unable to communicate the poor fitment to the assistant personnel. It is also known from GB-A-2 232 337 to use longitudinal strips for belt fastening, whereby the strip is placed lengthways along the length of the belt portion. In this way, the risk of the hook element strip contacting the body above or below the longitudinal edges of the belt portion is reduced. The extent of the strip in the longitudinal direction of the belt portion is consequently considerable in order to be able to achieve adequate shear strength of the releasable fastener. This brings with it however the disadvantage that the strips may not properly overlap and will thus contact the wearer's body although at a different location. Such is of particular importance where the belt is slightly too small for example. Arrangement of the elongate strip of hook elements along the width of the belt is known per se from FR-A-2 586 558, where a small margin between the edges of the strip and the outer edges of the belt is left. However, the size of such margin was not of importance to the inventors thereof and was thus nowhere considered. SUMMARY The aforementioned problems relating to fitting and comfort when wearing absorbent garments of the aforementioned type are solved by the features of the belt according to the present invention. The present invention provides a waist belt for an absorbent garment, including a flexible material having first and second ends and longitudinal edges, a distance between the ends defining a length of the belt for securing the belt around a waist of a user of the absorbent garment. Attachment means securely attached to the belt and located proximate one of the ends of the belt are provided for securing one end thereof directly to an attachment zone defined by an outer surface of the belt situated between the longitudinal edges thereof, a distance between the longitudinal edges defining a width of the belt and a width of the attachment zone. The outer surface of the belt is formed of a loop material at least in the attachment zone of the outer surface of the belt at which the one end is to be attached. The attachment means is a hook element strip of a releasable type, which extends with its greatest dimension in a width direction of the belt, the greatest dimension of the attachment means is in the range of 25% to 75% of the width of the attachment zone taken at a location of the outer surface of the belt at which one end is to be attached to thereby reduce the risk of the attachment means contacting the user of the absorbent garment when the belt is secured around the waist of the user. It should be noted that, while the term "absorbent garment" has been used in conjunction with incontinence, and particularly adult incontinence, the invention is not limited to this particular use or any particular size or particular type of absorbent garment implied thereby and it is clear for the skilled man that such belts could be used with baby's or children's diapers for example, merely by adapting the dimensions and materials appropriately. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be explained in more detail with reference to certain non-limiting embodiments and with reference to the accompanying drawings, in which FIG. 1 depicts one embodiment of a separate belt in accordance with the invention whereby, for purposes of clarity, the belt is shown looped in the opposite manner to that obtained upon wearing; FIG. 2 depicts a further embodiment of a separate belt according to the invention wherein the belt is of the reversible type, capable of being used either way round; FIG. 3 shows an absorbent garment in the form of a chassis, adapted for fitting to the belt of the invention; FIG. 4 shows a belt according to the invention laid out flat; FIG. 5 shows a plan view of a reversible belt similar to that in FIG. 2; FIG. 6 shows three possible embodiments, in FIGS. 6(A), 6(B) and 6(C) of elongate hook element strips of the belt of the present invention, and FIG. 7 shows an embodiment of an absorbent garment having an integrated belt in accordance with the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows a belt generally denoted 1 which is made of flexible material such that it can be wrapped around a user's waist. The belt in FIG. 1 is shown, for reasons of clarity, wrapped around an imaginary center point in a manner opposite to that normally used when fitted to a user. Thus the inside of the belt 8 is here shown as if it were on the outside. The belt is substantially rectangular in shape comprising two laterally spaced longitudinal edges 3 and 4 separated by a distance z (see FIG. 4). At one end, the belt is foreseen with an end portion 13 here shown as having a reduced width, on which end portion is securely affixed a flexible strip 6 having hook elements. This strip is of the type forming one half of the joining portions of a hook and loop type fastening means. The loop part of the joint in the embodiment shown is thus formed by the belt material itself. The outside surface 5 of the belt 1 (depicted in FIG. 1 as the inside) serves as an area of releasable attachment, partly for the strip 6 located at one end of the belt and also for similar strips 6' and 6" of a chassis 2 having absorbent material 14 therein (see FIG. 3). On the outside surface 5 of the belt 1 there may also be a portion 7, formed by attaching a strip of suitable material to the outside surface 5 of the belt, to which the hook element strips 6' and 6" cannot attach. The manner of fitting a chassis 2 to the separate belt 1 will now be briefly described. Firstly the belt is passed around the wearer's waist and the hook element strip 6 is pressed lightly onto the releasable attachment surface formed by the outside surface 5 to fasten it in place. The chassis portion is then attached to the outside of the belt behind the wearer's back by attaching the two strips 6' (or alternatively strips 6") to the belt surface 5. The free end of the garment is then passed between the wearer's legs and secured by means of the strips 6" to the front of the belt. The manner of fitting the garment shown in FIG. 7 having an integrated belt is the same as above, except that no attachment of any strips 6" is required. In pressing the hook element strip 6 lightly into place, without the belt of the invention, it is easy not to take adequate care in preventing that the hook element strips project beyond the edges of the belt and thus touch the wearer. However, by using the belt of the invention this problem is obviated. Thus the strip 6 in FIG. 1 has a longitudinal extent "a" across the width of the belt which is between 25% and 75% of the width "z" thereof, preferably less than 60% and more preferably less than 50%. A further embodiment of the invention is shown in FIG. 2 and FIG. 5 which each show a reversible belt. Corresponding zones 5 and 12 are provided for releasable attachment on either side with or without a zone 7 on either or both sides. At one end of the belt there is attached an extra piece 20 of flexible material, which has attached thereto two strips 21 and 22 of hook elements, similar to the element 6 of FIG. 1. Depending on which way round the belt is worn, either one or the other hook element strip 21 or 22 can be used for fastening the belt. Thus each of the two strips has a length of between 25% and 75% of the belt width "z". Clearly advantageous with the use of such belts of the single sided type or the type which are integrated into an absorbent garment (see e.g. FIG. 7) is where at least some of the inner surface material of the belt is moisture-absorbent. When the belt is integrated into an absorbent garment, it exhibits two ends 16, 17 extending outwardly from the sides of the absorbent garment, one of which includes the hook element strip 6. A woven material is normally used for both sides of a separate re-usable belt, or the outside of a disposable belt (integrated or not) due to its releasable attachability characteristics for hook element strips and also due to its washability. However non-woven, cheaper materials for the outside of the belt can be used with a hook element strip attachable to non-woven materials. In particular, when using non-woven materials for the releasable attachment surface of the belt it is possible to achieve particularly favorable peel strength and shear strength combinations, which give a peel strength of 0.1-2.0 Ncm -1 , preferably down to as low as 0.2-0.8 Ncm -1 , and a shear strength greater than 1 Ncm -2 , preferably greater than 15 Ncm -2 and normally greater than 20 Ncm -2 . In this way, the strip of material can be made very thin and also with its largest dimension closer to 50% or even less of the belt width. As can be seen from FIG. 6, showing three possible strip embodiments 9, 10, and 11, the extent "a" between the outer edges of the strip(s) leaves a distance or margin "b" from each edge 3, 4 of the belt. The larger the distance "b", the less the risk that the strip portions 9, 10, or 11, will touch the wearer when the belt is fitted slightly incorrectly. As can be seen, the strips are generally elongate, or in the case of a series of strips 10 as in FIG. 6(B), the series of strips is elongate. By elongate is meant that the dimension "a" is larger than dimension "c". Preferably a ratio of a:c greater than 2:1 is used and even more preferably a ratio of over 3:1. Thus, to achieve the aforementioned advantages, the strips with their larger dimension "a" are laid across the belt width (z), as depicted, to give the strips a dimension such that the larger dimension "a" has a length of between 25% and 75% of the width (z) of the main area (5) of the belt, which width (z) for adult incontinence applications lies between 70 to 160 mm. By width of the belt, is hereby meant the width of the belt at the zone where the strip 9, 10, 11 will attach. Thus in the embodiment of FIG. 6(C), although the strip 11 extends entirely across the reduced portion of the belt, the strip length "a" still lies within the stated range of values. Whilst the embodiment of FIG. 6(B) shows three strips sections 10, it is clear that two or more than three could be used. However, it is the distance "a" between the outer edges of the outermost strips that is the dimension which must fall within the range 25% to 75%, preferably being less than 60%, or more preferably less than 50%. As will be noted, the strips or series of strips are placed substantially in the middle of the belt width, such that the two margins "b" are substantially equal for any given belt. The area denoted by "d" in FIG. 6(A) is a finger-grip portion of the end of the belt for unfastening the belt by simple lifting and consequent peeling of the hook element strip from where it is attached to the belt. By use of a thin strip, as described above and which has low peel strength, it is possible to reduce distance "d" to an absolute minimum, thus saving belt material and reducing cost. Whilst particular embodiments of the invention have been described above, it is to be understood that these do not limit the scope of the invention which is defined by the claims appended hereto.	The invention relates to a belt (1) of flexible material for use with absorbent garments, wherein the belt comprises attachment means (6, 9, 10, 11, 21, 22) securely attached at one end. The attachment means is in the form of a flexible strip of hook elements such as used for releasable hook and loop type connectors and is used for securing that one end to an outer surface of the belt. In order to provide greater comfort for the wearer the attachment means itself is located approximately centrally and extends with its greatest dimension (a) in the width direction of the belt where dimension (a) is between 25% to 75% of the belt width (z).	0
BACKGROUND OF THE INVENTION [0001] The invention relates to an electric storage water heater with double cathodic protection. [0002] Two types of cathodic protection are known for protecting an electric storage water heater against corrosion: either cathodic protection using a sacrificial anode such as a magnesium anode, or cathodic protection using an impressed current permanent anode. [0003] The magnesium anode needs to be replaced periodically when it reaches the end of consumption, whilst the impressed current anode needs to be constantly fed by an electrical power source in order to provide cathodic protection. DESCRIPTION OF THE PRIOR ART [0004] Document WO 2007/010335 describes an electric storage water heater with adjustable cathodic protection. This electric storage water heater is protected against corrosion under normal operating and power supply conditions by an impressed current permanent electrode, whilst the water heater is protected in the absence of power by a sacrificial anode. The sacrificial anode is electrically connected to the tank of the water heater by a switch that is intended to break the electrical connection when the power supply feeds said impressed current permanent electrode. This device is generally satisfactory, but specifically requires the sacrificial anode to be disconnected when there is a power supply, to prevent the excessive consumption thereof. SUMMARY OF THE INVENTION [0005] A first objective of the invention is to improve the known prior art, by proposing a novel electric storage water heater with double cathodic protection, that does not require the sacrificial anode to be disconnected when there is a power supply, while preventing excessive consumption. [0006] A second objective of the invention is to provide the cathodic protection of an electric storage water heater, even using an off-peak-hours power supply system that involves a lack of power for long durations of around 16 hours. [0007] One subject of the invention is a storage water heater with double cathodic protection, comprising a sacrificial anode and an impressed current anode, wherein the sacrificial anode surrounds the impressed current anode and has a conformation suitable for avoiding any contact of the impressed current anode with the water of the tank of the electric water heater, before consumption of the sacrificial anode. [0008] As claimed in other alternative features of the invention: the impressed current anode is in electrical contact with the sacrificial anode; the sacrificial anode comprises a recess for mounting the impressed current anode; the sacrificial anode is mounted on a support or a retaining sheath by means of an elastomeric sleeve; the impressed current anode is mounted on a support or a retaining sheath by means of an elastomeric sleeve; the elastomeric sleeve of the sacrificial anode surrounds the elastomeric sleeve of the impressed current anode; the dimensions of the sacrificial anode are significantly greater than the dimensions of the impressed current anode; the sacrificial anode and impressed current anode have substantially cylindrical conformations; the diameter of the sacrificial anode is substantially greater than the diameter of the impressed current anode; and the impressed current anode is made of titanium and the sacrificial anode is made of magnesium. BRIEF DESCRIPTION OF THE DRAWINGS [0018] The invention will be better understood by virtue of the description which will follow, given by way of non-limiting example with reference to the appended drawings in which: [0019] FIG. 1 schematically represents an electric storage water heater as claimed in the invention. [0020] FIG. 2 schematically represents a partial enlarged view illustrating the device for cathodic protection of the electric storage water heater from FIG. 1 . [0021] FIG. 3 schematically represents a partial view analogous to FIG. 2 illustrating the operation of the invention. [0022] FIG. 4 schematically represents a partial view analogous to FIGS. 2 and 3 illustrating the operation of the invention after consumption of the sacrificial anode. [0023] With reference to FIGS. 1 to 4 , identical or functionally equivalent elements are identified by identical reference numbers. DESCRIPTION OF THE PREFERRED EMBODIMENT [0024] In FIG. 1 , an electric storage water heater denoted in its entirety by ( 1 ) comprises a tank ( 2 ), a retaining sheath ( 3 ), a voltage generator ( 4 ), a sacrificial anode ( 5 ) and an impressed current anode ( 6 ). [0025] The electric circuit of cathodic polarization comprises the sacrificial anode ( 5 ) in electrical contact with the impressed current anode ( 6 ) made, for example, of titanium. [0026] The mounting of the magnesium sacrificial anode ( 5 ) and of the titanium impressed current anode ( 6 ) on the retaining sheath ( 3 ) is carried out by one of the insulating retaining means ( 7 ) and ( 8 ) which are described in detail with reference to FIG. 2 . [0027] An insulated conductor ( 9 ) for supplying power and an insulated conductor ( 10 ) for connecting to the tank ( 2 ) of the water heater ( 1 ) are provided in order to connect the protection current generator ( 4 ) to the electric storage water heater ( 1 ). [0028] In FIG. 2 , the magnesium sacrificial anode ( 5 ) comprises a recess for mounting the titanium impressed current anode ( 6 ), so as to almost entirely embed the titanium anode ( 6 ) within the magnesium anode ( 5 ). [0029] The titanium anode ( 6 ) is mounted on the retaining support ( 3 ) with the aid of an insulating and flexible sleeve, for example made of an elastomer, over the outer circumference of the retaining sheath ( 3 ). [0030] The space inside the elastomeric sleeve ( 8 ) is connected to the atmosphere of the inside of the insulating support ( 3 ), without any contact with the water that fills the tank of the water heater. [0031] The magnesium sacrificial anode ( 5 ) is mounted on the insulating support or retaining sheath ( 3 ) by means of an elastomeric insulating sleeve ( 7 ) positioned over the periphery of the insulating support ( 3 ). [0032] In the case of a new sacrificial anode ( 5 ), the space between the elastomeric sleeves ( 7 ) and ( 8 ) is isolated from the water of the tank of the water heater due to the fact that the radially outer sleeve ( 7 ) completely surrounds the upper end of the retaining sheath ( 3 ) bearing the elastomeric sleeve ( 8 ). [0033] The externally insulated electrical conductor ( 9 ) is connected to the titanium impressed current anode ( 6 ) so that the titanium impressed current anode ( 6 ) may be constantly powered during the electric power supply periods of the electric storage water heater. [0034] In FIG. 3 , at the start of operation, the titanium impressed current anode ( 6 ) is not in contact with the water of the water heater, and the current which passes through this titanium impressed current anode can only be discharged through the magnesium sacrificial anode ( 5 ). Due to the fact that the diameter and the general dimensions of the magnesium sacrificial anode ( 5 ) are much greater than the diameter and the dimensions of the titanium impressed current anode ( 6 ), the current densities passing through the magnesium anode are much lower than those passing through the titanium anode. [0035] However, the provision of the cathodic polarization current makes it possible to slightly increase the protective electrochemical current which is naturally established between the magnesium sacrificial anode ( 5 ) and the tank ( 2 ) of the electric storage water heater, thus reinforcing the effect thereof. [0036] Thus, by virtue of the invention, the electric storage water heater is constantly protected, even in the case of an electric power supply that is interrupted over time, using only off-peak-hours power. [0037] The operation of the electric water heater as claimed in the invention is thus practically identical to the operation of an electric water heater of the prior art protected solely by a magnesium sacrificial anode. [0038] In FIG. 4 , the magnesium sacrificial anode has been practically consumed. The space between the sleeves ( 7 ) and ( 8 ) is then at least partially filled by the water which is inside the tank of the water heater, and the titanium impressed current anode ( 6 ) is at least partially in contact with the water of the water heater. [0039] In this case, the operation of the electric water heater as claimed in the invention is identical to the operation of an electric storage water heater of the prior art equipped with a titanium impressed current anode. [0040] The invention described in reference to one particular embodiment is in no way limited thereto, and on the contrary covers any modification of form and any embodiment variant within the scope and spirit of the invention.	An electric storage water heater with double cathodic protection includes a sacrificial anode ( 5 ) and an impressed current anode ( 6 ) combined so as to provide cathodic protection, even in the absence of a power supply. The sacrificial anode ( 5 ) surrounds the impressed current anode ( 6 ) so as to prevent any contact of the impressed current anode ( 6 ) with the water of the water tank before consumption of the sacrificial anode ( 6 ).	5
BACKGROUND OF THE INVENTION [0001] The invention generally resides in the field of quick release roller sleeves. Roller sleeves, which are mountable and demountable from rollers and other hub-like cylindrical structures, are used in several forms of printing, metal flattening, and other manufacturing processes. [0002] The manner in which roller sleeves are currently being mounted and demounted on the roll cores has caused problems in terms of increasing time of production due to the time required in changing the sleeve and core together which can take up to an hour or more during which time the machine onto which the roller sleeve is being mounted is shut down. Moreover, once a sleeve and core have been changed there may be issues with alignment which can lead to several wasted batches of product while the user makes alignment corrections which adds more downtime to production. Accordingly there exists a need for a quick release roller sleeve mounting hub, which cuts down significantly on the time spent on changing a roller sleeve during production and also does not require the need to remove or change the roller core eliminating the need for realigning the replacement core. [0003] The present invention overcomes these deficiencies by utilizing a quick release roller sleeve mounting hub having a fiberglass covering. The mounting hub remains in place on the machine and, instead of the entire apparatus being removed and replaced, an outer rim flange portion can slide into and out of position for ease of dismounting a worn roller sleeve and mounting a new roller sleeve around the hub that remains in its machine mounted position at all times. The present invention allows for the existing core or hub to be continued in service while only changing the outer roller sleeve portion, resulting in the overall sleeve and core to maintain its alignment and original configuration. [0004] Therefore, an object of the present invention is to provide a quick release roller sleeve which can be mounted and dismounted in a much shorter period of time. Another object of the present invention is to provide a quick release roller sleeve which can be mounted and dismounted without removing the roller core. [0005] A further object of the present invention is to provide a quick release roller sleeve made from fiberglass or other composite type long-lived material. Yet another object of the present invention is to provide a quick release roller sleeve with variable face lengths and diameters. Still another object of the present invention is to provide a quick release roller sleeve which is fastened to the core by a limited number of securing means to aid in the ease of mounting and dismounting of the roller sleeve. [0006] Another object of the present invention is to provide a quick release roller sleeve mounting hub that allows the outer sleeve portions to slide into and out of position for ease of mounting and dismounting once the roller sleeve is worn and needs to be replaced. Still another object of the present invention is to provide a quick release roller sleeve mounting hub that allows for use of the existing core or hub while only changing the outer roller sleeve portion, allowing the core to maintain its original configuration and alignment on the machinery. [0007] Other objects will appear hereinafter. SUMMARY OF THE INVENTION [0008] The present apparatus may be described as a quick release roller sleeve and mounting hub for mounting to a high speed machine for printing, metal flattening or other similar functions. The quick release roller sleeve is configured to mount over and around the mounting hub or core of the assembly. Each roller sleeve is constructed of fiberglass or other composite type material with an elastomeric covering. The roller sleeve fits around the mounting hub and is sandwiched between an inward facing flange and an outward facing flange, both of which completely circumscribe the hub. Each of the flanges has a circumferential notch that mounts against the sleeve base capturing and containing the sleeve between the flanges with the sleeve supported by the hub or core. The flange notches allow for the sleeves to be appropriately positioned within the flanges and around the hub or core so that the roller sleeve, when worn and needing to be replaced, is able to slide into and out of place for ease of mounting and dismounting. The present invention allows for the existing core to remain in its aligned position on the machinery while changing only the roller sleeve portion, which allows for the entire assembly to maintain its original configuration. [0009] The inner and outer facing flange plates are structurally identical. The inner facing flange plate is permanently secured to the metal hub or core with a plurality of threaded machine bolts in this way an existing core can be used and it can even be returned to its original configuration if desired. The outer facing flange plate is used to mount and dismount the roller sleeve by removing the flange from the hub or core, sliding the roller sleeve outward and away from the inner facing flange and off of the hub or core, mounting a new roller sleeve onto the hub or core, and replacing the outer flange to secure the sleeve in position. The outer facing flange plate provides a pinching effect on the roller sleeve between its inner surface and the inner surface of the inner facing flange plate. To maintain the roller sleeve in position and resist against slippage the paired flange plates exert an inward force against the roller sleeve that is captured in opposing flanges and bevels around the periphery of each of the flange plates. The inner facing flange, mounting hub and sleeve are assembled prior to mounting on the machinery and remain assembled until such time as the core or hub is being switched out as well. [0010] It is sometimes advisable to maintain rotational speed and avoid slippage that the hub or the roller sleeve are engaged with each other, or with the high speed machinery by a key and cooperating keyway. The embodiments described below are each substantially similar in structure and may be utilized for differently dimensioned workpieces, some wider than others. [0011] These together with other objects of the present invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0012] For the purpose of illustrating the invention, there is shown in the drawings forms which are presently preferred; it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. [0013] FIG. 1 is a sectional side view of the quick release roller sleeve and mounting hub of the present invention. [0014] FIG. 1A is an enlarged view of the outer flange edge region on the machine side of the hub as it captures the roller sleeve mounted around the hub. [0015] FIG. 1B is an enlarged view of the outer flange edge region on the exposed side of the hub as it captures the roller sleeve mounted around the hub. [0016] FIG. 2 is a front view of the quick release roller sleeve and mounting hub assembly of the present invention. [0017] FIG. 3 is an exploded side view of the quick release roller sleeve and mounting hub assembly of the present invention. [0018] FIG. 4 is a sectional side view of a second embodiment of the quick release roller sleeve and mounting hub of the present invention. [0019] FIG. 5 is a front view of the second embodiment of the quick release roller sleeve and mounting hub of the present invention. [0020] FIG. 6 is an exploded side view of the second embodiment of the quick release roller sleeve and mounting hub of the present invention. [0021] FIG. 7 is a partial sectional side view of a third embodiment of the quick release roller sleeve and mounting hub of the present invention. [0022] FIG. 8 is an exploded side view of the third embodiment of the quick release roller sleeve and mounting hub of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] The following detailed description is of the best presently contemplated mode of carrying out the invention. The description is not intended in a limiting sense, and is made solely for the purpose of illustrating the general principles of the invention. The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings. [0024] Referring now to the drawings in detail, where like numerals refer to like parts or elements, there is shown in FIG. 1 , the quick release roller sleeve and mounting hub assembly 10 of the present invention. The quick release assembly is comprised of a pair of opposing outer and inner flange plates 12 a , 12 b , a mounting hub 14 having an outer support rim 16 , and a roller sleeve 18 . The inner flange plate 12 b is secured to the support rim 16 across the inward face of the hub 14 by a set of mounting screws 13 b . Likewise, the outer flange plate 12 a is secured to the support rim 16 across the outward face of the hub 14 by a set of mounting screws 13 a . Alternatively, the inner flange plate 12 b may be manufactured as part of the hub 14 as it is not required to be removed to dismount and mount a roller sleeve 18 . [0025] Referring to FIG. 1A , the inner flange plate 12 b captures the base 20 of roller sleeve 18 within cooperating circumferential notch 19 slightly inward of the outer edge of the flange plate 12 b . The outer roller material 22 of sleeve 18 extends outward from the base 20 in accordance with the general dimensions set forth below. The base 20 of roller sleeve 18 is constructed of fiberglass or other composite resin-type material. The resin material may be any suitable thermoset such as an epoxy or polyester. The thickness of the base 20 of the roller sleeve 18 is in the range of 1/16 to ¼ inches to provide stability to the outer roller material 22 . As can be seen from FIG. 1B , the identical arrangement is provided for the outer flange plate 12 a in capturing the base plate 20 of the roller sleeve 18 . The base 20 of the roller sleeve 18 is captured in the circumferential notch 19 of the outer flange plate 12 a locking the roller sleeve 18 in position between the flange plates 12 a , 12 b with both mounted to the hub 14 . [0026] The support rim 16 of the mounting hub 14 is slightly smaller than the roller sleeve 18 in depth and diameter which allows the roller sleeve 18 to slide onto the mounting hub 14 . Each of the flange plates 12 a , 12 b extends the flat surface of the support rim 16 and pinches the base 20 of the roller sleeve 18 between them to secure the roller sleeve 18 to the mounting hub 14 as described above. The flange plates 12 a , 12 b seal the edges of the roller sleeve 18 between them and grip the base 16 to prevent the roller sleeve 18 from slipping while in use. The roller sleeve 18 can be any elastomer or synthetic rubber, preferably a urethane composition having a shore A hardness of 40 to 60 and a wall thickness of 0.25 to 1.00 inches. The face width of the roller sleeve preferably ranges from 4 to 10 inches and the diameter can range between 12 to 25 inches. Other dimensional measurements may be consistent with special uses of the roller sleeve 18 that can be manufactured to meet the requirements of the machinery dimensional specifications. [0027] The enlarged view in FIG. 1A of the junction between the inner flange plate 12 b and the roller sleeve 18 more clearly shows the cooperating circumferential notch 19 in the flange 12 b as it captures the edge of the base 20 of the roller sleeve 18 . The circumferential notch 19 and shoulder 21 allows the outer flange plate 12 b to slide into and out of place against the mounting hub 14 for ease of mounting and dismounting when the roller sleeve 18 is worn and needs to be replaced. The circumferential notch 19 on the flange plate 12 b is approximately 0.012 inches and accepts the more rigid base 20 of the roller sleeve 18 forming a snug fit between them. There is another undercut or bevel 23 along the outer periphery of each flange plate 12 a , 12 b to accommodate the outer roller material 22 of roller sleeve 18 therebetween. See, FIG. 1B . The removal of the outer flange plate 12 a from the mounting hub 14 , by removing only the mounting screws 13 a and sliding the roller sleeve 18 off of and away from the mounting hub 14 , allows for the existing mounting hub 14 to remain in position while changing only the roller sleeve 18 and without disengaging the inner flange plate 12 b . Thus, the end user can replace a worn roller sleeve 18 by removing only the outer flange plate 12 a . Then it becomes a requirement for maintaining machine up time for only the roller sleeve 18 to be inventoried by the end user for a rapid exchange of a new part for a worn one. [0028] FIG. 2 shows an outer front face view of the quick release roller sleeve mounting hub assembly 10 of the present invention. In this first embodiment, the quick release assembly 10 has a large diameter mounting hub 14 including a set of six apertures 15 through which a series of fastening means extend for attaching the mounting hub 14 to the machinery. The apertures 15 are spaced about the inner circumferential opening of the mounting hub 14 at points approximating 60° separations between each of them. Shown in the inner flange plate 12 b are a set of four mounting apertures 13 d for mounting the flange plate to the mounting hub 14 . As can be seen from FIG. 3 , the outer flange plate 12 a also has a set of four mounting apertures 13 c for mounting the flange plate 12 a to the mounting hub 14 . The mounting apertures 13 c , 13 d are spaced about the periphery of the outer flange plates 12 a , 12 b at points approximating 90° separations between each of them. [0029] Referring now to FIG. 3 , there is shown an exploded view of the present invention, the quick release sleeve and mounting hub assembly 10 . Starting from the left, the inner facing flange plate 12 b has a shoulder 21 that mates to the outer diameter 17 of the support rim 16 of the mounting hub 14 and an outwardly extending bevel 23 at the peripheral circumference of the plate 12 b with the notch 19 located in between them. The inner flange plate 12 b is mounted to the support rim 16 with fasteners 13 b that extend through apertures 13 d into threaded receiving holes 13 f in the support rim 16 . [0030] The support rim 16 provides a base for the attachment of the paired inner and outer flange plates 12 a , 12 b . The outer circumference of the support rim 16 provides the support for the roller sleeve 18 with the two parts being dimensioned such that the inner diameter face 25 of the roller sleeve 18 slips over and contacts the outer diameter 17 face of the support rim 16 . The roller sleeve 22 is seated on the support rim 16 and pinched between the paired outer flange plates 12 a , 12 b . Also formed by the mating alignment of the flange plates 12 a and 12 b and the roller sleeve 18 is a seal that acts to prevent liquids used with the roller assembly from entering into the space between the roller sleeve 18 and the hub 14 that could retard the ease in dismounting the roller sleeve 18 when worn. [0031] The outward facing flange plate 12 a mounts to the support rim 16 in the same way as the inner flange plate 12 b with fasteners 13 a that extend through apertures 13 c into threaded receiving holes 13 e in the support rim 16 . At the center of the support rim 16 is the mounting hub 14 that surrounds the central aperture utilized to mount the support rim 16 to the roller hub (not shown). Each of the apertures 15 are used to affix the mounting hub 14 to the roller hub when originally positioning the assembly 10 . In this way, the mounting hub 14 remains affixed to the roller hub and only the roller sleeve 18 , when worn, need be replaced by removing only the outer flange plate 12 a , replacing the roller sleeve 18 and then replacing the outer flange plate 12 a , all without dismounting the entire assembly 10 or disturbing the mounting hub alignment on the roller hub and allowing for only minimal down time of the machinery. During the exchange of the roller sleeve 18 , the inner facing flange plate 12 b remains attached to the mounting hub 14 . [0032] Shown in FIG. 4 is a second embodiment of the quick release roller sleeve and mounting hub assembly 110 of the present invention having a differently sized central aperture for mounting to a roller hub. The quick release assembly is comprised of a pair of opposing inner and outer flange plates 112 a , 112 b , a mounting hub 114 having an outward facing support rim 116 , and a roller sleeve 118 . The inner flange plate 112 a is secured to the support rim 116 across an inner space 130 dimensioned exactly to the length of quadrilaterally positioned spacer blocks 132 a - 132 d mounted to the inner flange plate 112 a . The spacer blocks 132 b and 132 d overlie one another in the view presented with spacer block 132 b shown in phantom lines. The quadrilaterally positioned spacer blocks 132 a - 132 d extend across the inner space 130 and provide a connecting point for the support rim 116 as well as a positioning and mounting point for the roller sleeve 118 that extends around the outer circumference of the outer flange plate 112 a but inside of the outer flange 123 a . The inward face of the support rim 116 lies against the set of spacer blocks 132 a - 132 d . A set of mounting screws 113 a extend through the outer flange plate 112 a through the support rim 116 and into the set of spacer blocks 132 a - 132 d as shown in FIGS. 4 and 6 . [0033] As can be seen from FIGS. 4 and 6 , the outer flange plate 112 b captures the base 120 of roller sleeve 118 within a cooperating circumferential notch 119 b slightly inward of the outer edge of the flange plate 112 b . The outer roller material 122 of sleeve 118 extends outward from the base 120 in accordance with the general dimensions set forth below. The base 120 of roller sleeve 118 is constructed of fiberglass or other composite resin-type material. This resin material may be any suitable thermoset such as an epoxy or polyester. The thickness of the base 120 of the roller sleeve 118 is in the range of 1/16 to ¼ inches to provide stability to the outer roller material 122 . The cooperating circumferential notch 119 b and undercut or bevel 123 b extending outward from the flange plate 112 b captures the roller sleeve 118 between these named elements on the outer flange plate 112 b and the same arrangement of elements 119 a , 123 a on the inner flange plate 112 a . This structural arrangement is identical to that described in connected with FIGS. 1A and 1B . [0034] The outer diameter of the support rim 116 is slightly smaller than the diameter of the roller sleeve 118 which allows the roller sleeve 118 to slide over the support rim 116 and onto the inner flange plate 112 b . The flange plates 112 a , 112 b when positioned opposing one another capture the edges of the roller sleeve 118 between them and grip the base 120 to prevent the roller sleeve 118 from slipping while in use. As above, the roller sleeve 118 can be any elastomer or synthetic rubber, preferably a urethane composition having a shore A hardness of 40 to 60 and a wall thickness of 0.25 to 1.00 inches. The face width of the roller sleeve preferably ranges from 4 to 10 inches and the diameter can range between 12 to 25 inches. Other dimensional measurements may be consistent with special uses of the roller sleeve 118 that can be manufactured to meet the requirements of the machinery dimensional specifications. [0035] The support rim 116 is dimensioned to fit within the outer flange plate 112 b when completing the remounting of the sleeve 118 . The support rim 116 is press fit over a mounting hub 114 that extends between the inner faces of the support rim 116 and the inner flange plate 112 a across the space 130 . Likewise, the inner flange plate is press fit over the hub 114 by fitting the central opening 115 a around the hub 114 . A pair of inner and outer collars 134 a , 134 b captures the inner flange plate 112 b and the support rim 116 respectively between them and against the mounting hub 114 . Both the outer flange plate 112 a and the support rim 116 have central openings 115 b , 117 , respectively, that accommodate the mounting hub 114 and allow the collars 134 a , 134 b to retain the inner flange plate 112 a and support rim 116 against and securely affixed to the mounting hub 114 . A first set of fastening means or screws 136 b are used to mount the support rim 116 to the mounting hub 114 . A second set of fastening means or screws 136 a are used to mount inner flange plate 112 a to the mounting hub 114 securing the collar 134 a to the mounting hub 114 . The screws 136 a , 136 b are spaced apart approximately 120° around the circumference of the collars 134 a , 134 b and extend through countersunk apertures 133 a , 133 b in the collars 134 a , 134 b into threaded receiving holes 135 a , 135 b in opposite sides of the mounting hub 114 . [0036] As is shown in FIGS. 4 and 6 , the mounting hub 114 fits into and against a matching inward flange in each of the inner flange plate 112 a and the support rim 116 with each of the collars 134 a , 134 b fitting into outward facing recesses 137 a , 137 b in the mounting hub 114 such that attachment the of these parts one to the other creates a rigid assembly for supporting the roller sleeve 118 . Also formed by the mating alignment of the flange plates 112 a and 112 b and the roller sleeve 118 is a seal that acts to prevent liquids used with the roller assembly from entering into the space between the roller sleeve 118 and the hub 114 that could retard the ease in dismounting the roller sleeve 118 when worn. [0037] FIG. 5 shows the front view of the second embodiment of the present invention 110 that exhibits a much smaller diameter central aperture for mounting the assembly to a machine or high speed roller apparatus than the larger diameter for mounting shown in FIG. 2 . The outer flange plate 112 b having a very large diameter opening such that the flange plate 112 b fits snugly over the support rim 116 and is mounted to the assembly containing the support rim 116 and the mounting hub 114 by four fastening means 113 b that are secured into threaded apertures 139 b located in each of the spacers 132 a - d . On the opposite side the outer flange plate 112 a is also secured in position using four fastening means 113 a that are secured into threaded apertures 139 a in each of the four spacers 132 a - d . The mounting hub 114 located at the center of the support rim 116 has a key notch 140 shown extending upwards from the round opening for engaging a keyed shaft of the machine or high speed roller apparatus. [0038] The exploded view in FIG. 6 of the second embodiment of the present invention 110 shows the differently configured mounting hub 114 being attached between the center portion of the support rim 116 and the inner flange plate 112 b . The removal of the outer flange plate 112 a exposes the roller sleeve 118 such that the roller sleeve 118 can be removed and replaced without having to remove the entire assembly 110 from the machine or high speed roller apparatus. In this way the assembly remains in its aligned position on the machine or high speed roller apparatus without the need for extended downtime to realign the roller sleeve 118 or the entire assembly 110 . [0039] A third embodiment of the quick release roller sleeve and mounting hub assembly 210 of the present invention is presented in FIGS. 7 , 8 . The quick release assembly is comprised of a pair of opposing inner and outer flange plates 212 a , 212 b , a mounting hub 214 having an outer support surface 216 , and a roller sleeve 218 . In this embodiment the exploded view of FIG. 8 depicts the outward facing side of the quick release assembly to the left instead of the right as was done in the prior two embodiments to demonstrate that the invention will work regardless of the mounting position. The inner flange plate 212 a is secured to the support surface 216 across the inward face of the hub 214 by a set of mounting screws 213 a . Likewise, the outer flange plate 212 b is secured to the support rim 216 across the outward face of the hub 214 by a set of mounting screws 213 b . The outer flange plate 212 b captures the base 220 of roller sleeve 218 within cooperating notch 219 slightly inward of the outer edge of the flange plate 212 b . Likewise, inner flange plate 212 a captures the base 220 of roller sleeve 218 within cooperating notch 219 slightly inward of the outer edge of the flange plate 212 a . The outer roller material 222 of sleeve 218 extends outward from the base 220 in accordance with the general dimensions set forth below. The base 220 of roller sleeve 218 is constructed of fiberglass or other composite resin-type material. The resin material may be any suitable thermoset such as an epoxy or polyester. The thickness of the base 220 of the roller sleeve 218 is in the range of 1/16 to ¼ inches to provide stability to the outer roller material 222 . [0040] The support surface 216 of the mounting hub 214 is slightly smaller than the roller sleeve 218 in depth and diameter which allows the roller sleeve 218 to slide onto the mounting hub 214 . Each flange plate 212 a , 212 b extends the flat surface of the support surface 216 and pinches the base 220 of the roller sleeve 218 between them (an within the respective notches 219 ) to secure the roller sleeve 218 to the mounting hub 214 . The flange plates 212 a , 212 b seal the edges of the roller sleeve 218 between them and grip the base 216 to prevent the roller sleeve 218 from slipping while in use. The roller sleeve 218 can be any elastomer or synthetic rubber, preferably a urethane composition having a shore A hardness of 40 to 60 and a wall thickness of 0.25 to 1.00 inches. The face width of the roller sleeve preferably ranges from 4 to 10 inches and the diameter can range between 12 to 25 inches. Other dimensional measurements may be consistent with special uses of the roller sleeve 218 that can be manufactured to meet the requirements of the machinery dimensional specifications. [0041] The exploded view in FIG. 8 shows one clearly the junction between the outer flange plate 212 b and the roller sleeve 218 and more clearly shows the cooperating notch 219 in the flanges 212 a , 212 b as they capture the edges of the base 220 of the roller sleeve 218 . The notch 219 and central aperture 225 allows the outer flange plate 212 b to slide into and out of place against the mounting hub 214 for ease of mounting and dismounting when the roller sleeve 218 is worn and needs to be replaced. The notch 219 on the flange plate 212 b is approximately 0.012 inches and accepts the more rigid base 220 of the roller sleeve 218 forming a snug fit between them. There is another undercut or bevel 223 along the outer periphery of each flange plate 212 a , 212 b to accommodate the outer roller material 222 of roller sleeve 218 therebetween. As described above, formed by the mating alignment of the flange plates 212 a and 212 b and the roller sleeve 218 is a seal that acts to prevent liquids used with the roller assembly from entering into the space between the roller sleeve 218 and the hub 214 that could retard the ease in dismounting the roller sleeve 218 when worn. [0042] The removal of the outer flange plate 212 b from the mounting hub 214 , by removing only the mounting screws 213 b and sliding the roller sleeve 218 off of and away from the mounting hub 214 , allows for the existing mounting hub 214 to remain in position while only changing the roller sleeve 218 . Thus, the end user can replace a worn roller sleeve 218 by removing only the outer flange plate 212 b . Then it becomes a requirement for maintaining machine up time for only the roller sleeve 218 to be inventoried by the end user for a rapid exchange of a new part for a worn one. [0043] In FIG. 8 the exploded side view of the second embodiment of the present invention 210 shows a roller hub that has been modified for secure mounting of the quick release roller sleeve assembly to a machine or high speed roller apparatus. The outer flange plate 212 b has an appropriately dimensioned aperture 225 such that the flange plate 112 b fits over the mounting hub 214 that provides the support surface 216 and is mounted to the assembly containing the inner flange plate 212 a , the support surface 116 , and the mounting hub 214 by a set of fastening means 213 b . The roller sleeve 218 has an inwardly extending key 240 shown extending part way along the length of the sleeve 218 from its proximal outer end for engaging a keyway 242 located along the support surface 216 on the mounting hub 214 . The engaging of the key 240 in the keyway 242 prevents the roller sleeve 218 from slipping and changing rotational speed as the hub 214 turns within the high speed machine. The removal of the outer flange plate 212 b exposes the roller sleeve 218 such that the roller sleeve 218 can be removed replaced without having to remove the entire assembly 210 from the machine or high speed roller apparatus. In this way the assembly remains in its aligned position on the machine or high speed roller apparatus without the need for extended downtime to realign the roller sleeve 218 or the entire assembly 210 . [0044] The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, the described embodiments are to be considered in all respects as being illustrative and not restrictive, with the scope of the invention being indicated by the appended claims, rather than the foregoing detailed description, as indicating the scope of the invention as well as all modifications which may fall within a range of equivalency which are also intended to be embraced therein.	A quick release roller sleeve and mounting hub assembly is described for use with high speed roller machines. The assembly includes an outer flange plate that can be detached from the assembly in order for the roller sleeve to be dismounted and a new roller sleeve mounted as the existing roller sleeve becomes worn and needs to be replaced. The quick release permits the mounting hub and other parts of the assembly to remain in their aligned configuration and positions while only exchanging the roller sleeve portion of the assembly.	8
FIELD OF THE INVENTION The present invention relates to the field of abrasive tool inserts and, more particularly, to such inserts having at least one angled contour at the diamond/substrate interface to provide improved durability and reduced susceptibility to spalling, cracking and wear of the diamond layer. BACKGROUND OF THE INVENTION Abrasive compacts are used extensively in cutting, milling, grinding, drilling and other abrasive operations. The abrasive compacts typically consist of polycrystalline diamond or cubic boron nitride particles bonded into a coherent hard conglomerate. The abrasive particle content of abrasive compacts is high and there is an extensive amount of direct particle-to-particle bonding. Abrasive compacts are made under elevated temperature and pressure conditions at which the abrasive particle, be it diamond or cubic boron nitride, is crystallographically stable. Abrasive compacts tend to be brittle and, in use, they are frequently supported by being bonded to a cemented carbide substrate. Such supported abrasive compacts are known in the art as composite abrasive compacts. The composite abrasive compact may be used as such in the working surface of an abrasive tool. Alternatively, particularly in drilling and mining operations, it has been found advantageous to bond the composite abrasive compact to an elongated cemented carbide pin to produce what is known as a stud cutter. The stud cutter is then mounted in the working surface of a drill bit or a mining pick. Fabrication of the composite is typically achieved by placing a cemented carbide substrate into the container of a press. A mixture of diamond grains or diamond grains and catalyst binder is placed atop the substrate and compressed under high pressure, high temperature (HPHT) conditions. In so doing, metal binder migrates from the substrate and "sweeps" through the diamond grains to promote a sintering of the diamond grains. As a result, the diamond grains become bonded to each other to form a diamond layer, and that diamond layer is bonded to the substrate along a conventionally planar interface. Metal binder remains disposed in the diamond layer within pores defined between the diamond grains. A composite formed in the above-described manner may be subject to a number of shortcomings. For example, the coefficients of thermal expansion and elastic constants of cemented carbide and diamond are close but not exactly the same. Thus, during heating or cooling of the polycrystalline diamond compact (PDC), thermally induced stresses occur at the interface between the diamond layer and the cemented carbide substrate, the magnitude of these stresses being dependent on the disparity in thermal expansion coefficients and elastic constants. Another potential shortcoming which should be considered relates to the creation of internal stresses within the diamond layer which can result in a fracturing of that layer. Such stresses also result from the presence of the cemented carbide substrate and are distributed according to the size, geometry and physical properties of the cemented carbide substrate and the polycrystalline diamond layer. European Patent Application No. 0133 386 suggests a PDC in which the polycrystalline diamond body is completely free of metal binders and is to be mounted directly on a metal support. However, the mounting of a diamond body directly on metal presents significant problems relating to the inability of the metal to provide sufficient support for the diamond body. The European Patent Application further suggests the use of spaced ribs on the bottom surface of the diamond layer which are to be embedded in the metal support. According to the European Patent Application, the irregularities can be formed in the diamond body after the diamond body has been formed, e.g., by laser or electronic discharge treatment, or during the formation of the diamond body in a press, e.g., by the use of a mold having irregularities. As regards the latter, it is further suggested that a suitable mold could be formed of cemented carbide; in such case, however, metal binder would migrate from the mold and into the diamond body, contrary to the stated goal of providing a metal free diamond layer. The reference proposes to mitigate this problem by immersing the thus-formed diamond/carbide composite in an acid bath which would dissolve the carbide mold and leach all metal binder from the diamond body. There would thus result a diamond body containing no metal binder and which would be mounted directly on a metal support. Notwithstanding any advantages which may result from such a structure, significant disadvantages still remain, as explained below. In sum, the European Patent Application proposes to eliminate the problems associated with the presence of a cemented carbide substrate and the presence of metal binder in the diamond layer by completely eliminating the cemented carbide substrate and the metal binder. However, even though the absence of metal binder renders the diamond layer more thermally stable, it also renders the diamond layer less impact resistant. That is, the the diamond layer less impact resistant. That is, the diamond layer is more likely to be chipped by hard impacts, a characteristic which presents serious problems during the drilling of hard substances such as rock. It will also be appreciated that the direct mounting of a diamond body on a metal support will not, in itself, alleviate the previously noted problem involving the creation of stresses at the interface between the diamond and metal, which problem results from the very large disparity in the coefficients of thermal expansion between diamond and metal. For example, the thermal expansion coefficient of diamond is about 45×10 -7 cm/cm/°C. as compared to a coefficient of 150-200×10 -7 cm/cm/°C. for steel. Thus, very substantial thermally induced stresses will occur at the interface. In addition, once the portions of the diamond which do not carry the ribs begin to wear sufficiently to expose the metal therebehind, that metal will wear rapidly, due to its relative ductility and lower abrasion/erosion resistance, and undermine the integrity of the bond between the diamond and the metal support. Recently, various PDC structures have been proposed in which the diamond/carbide interface contains a number of ridges, grooves or other indentations aimed at reducing the susceptibility of the diamond/carbide interface to mechanical and thermal stresses. In U.S. Pat. No. 4,784,023, a PDC includes an interface having a number of alternating grooves and ridges, the top and bottom of which are substantially parallel with the compact surface and the sides of which are substantially perpendicular the compact surface. U.S. Pat. No. 4,972,637 provides a PDC having an interface containing discrete, spaced recesses extending into the cemented carbide layer, the recesses containing abrasive material (e.g., diamond) and being arranged in a series of rows, each recess being staggered relative to its nearest neighbor in an adjacent row. It is asserted in the '637 patent that as wear reaches the diamond/carbide interface, the recesses, filled with diamond, wear less rapidly than the cemented carbide and act, in effect, as cutting ridges or projections. When the PDC is mounted on a stud cutter, as shown in FIG. 5 of the '637 patent, the wear plane 38 exposes carbide regions 42 which wear much more rapidly than the diamond material in the recesses 18. As a consequence, depressions develop in these regions between the diamond filled recesses. The '637 patent asserts that these depressed regions, which expose additional edges of diamond material, enhance the cutting action of the PDC. U.S. Pat. No. 5,007,207 presents an alternative PDC structure having a number of recesses in the carbide layer, each filled with diamond, which make up a spiral or concentric circular pattern, looking down at the disc shaped compact. Thus, the '207 structure differs from the '637 structure in that, rather than employing a large number of discrete recesses, the '207 structure uses one or a few elongated recesses which make up a spiral or concentric circular pattern. FIG. 5 in the '207 patent shows the wear plane which develops when the PDC is mounted and used on a stud cutter. As with the '637 patent, the wear process creates depressions in the carbide material between the diamond filled recesses. Like the '207 patent, the '637 patent also asserts that these depressions which develop during the wear process enhance cutting action. Whereas the aforementioned patents assert a desirable cutting action in the rock, it is also highly desirable to minimize the diamond layer's susceptibility to fracture and spalling which in part arises from the internal residual stresses. Accordingly, it would be highly desirable to provide a polycrystalline diamond compact having increased resistance to diamond spalling fractures. SUMMARY OF THE INVENTION One object of the present invention is a polycrystalline compact having increased useful life. Another object of the present invention is a polycrystalline diamond compact having a diamond layer formed such that there is reduced spalling and cracking of the diamond layer as the compact wears. A further object of the invention is a PDC in which the carbide layer provides increased mechanical support, for the diamond layer as the compact wears. for the diamond layer as the compact wears. Still another object of the invention is a PDC in which the diamond-carbide interface is so designed to reduce residual tensile stresses in the location where spalling or delamination usually occurs. These, as well as other objects and advantages, are provided by an improved polycrystalline diamond compact having angled contours in the carbide layer, said layer being covered with diamond or other abrasive material shaped such that it provides outwardly sloping profiles at the periphery edge of the compact. Advantageously, the outwardly sloping profiles are disposed in such ways as to provide stress reduction benefit across the most useful portion of the compact during its wear-resistant lifetime. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be appreciated by those skilled in the art after reading the Detailed Description below, which is intended to be read in combination with the following set of figures, in which: FIG. 1 depicts a cross-sectional view of a PDC having a single outwardly sloping angled contour in the vicinity of the cutting edge; FIG. 2 depicts a cross-sectional view of a PDC having an outwardly sloping pattern at its periphery and an inwardly sloping pattern at its center; FIG. 3 depicts top and cross-sectional views of a PDC having a single sloping plane edge at the interface in accordance with the invention; and FIG. 4 depicts top and cross-sectional views of a PDC having a concentric sloping contour extending from the cutting edge to the center of the compact. FIG. 5 depicts top and cross-sectional views of a PDC having a sloping concentric contour which intersects the top surface of the compact. DETAILED DESCRIPTION OF THE INVENTION Reference is now made to FIG. 1 which shows an exemplary cross-sectional profile of a PDC in accordance with the invention. PDC 10 includes a substrate 11, preferably comprised of cemented carbide, and an abrasive layer 12, preferably comprised of polycrystalline diamond. Abrasive layer 12 is integrally bonded to substrate 11 and, in the typical manufacturing process, will be formed thereon by HPHT processing. For reference, FIGS. 1 and 2 depict the cutting edge 25 and anticipated wear plane 16. In application, edge 25 and plane 16 will, of course, depend on the manner in which PDC 10 is mounted on a stud cutter or other support means. As illustratively depicted in FIG. 2, PDC 10a, the cross sectional profile of the boundary between substrate 11 and abrasive layer 12 comprises a plurality of sloped surfaces, including outwardly sloping surfaces 14, and inwardly sloping surfaces 15. In each of the embodiments, surface 14 slopes outwardly and downwardly toward cutting edge 25 and is angled between about 10 to about 50 degrees and more preferably between about 25 and 45 degrees with the top surface of abrasive layer 12. In use, as PDC 10 wears, wear plane 16 (which represents the surface providing cutting action) slowly progresses toward the center of the compact. Until wear plane 16 reaches the first sloping surface 14, wear plane 16 intersects only the abrasive layer 12, which provides excellent cutting and wear characteristics. Compared to abrasive layer 12, substrate layer 11 wears relatively quickly. Therefore, once wear plane 16 descends beyond the first sloping surface 14, the substrate material 11 intersecting wear plane 16 erodes away more quickly and a diamond lip forms according to accepted understanding to those knowledgeable of typical PDC wear characteristics. During drilling, PDC 10 experiences very high stresses in the abrasive, or diamond, layer 12, particularly near the interface with substrate 11. Such stresses, some of which have been previously discussed, lead to fracturing and spalling in the diamond layer. These application stresses occur randomly and intermittently during drilling. They vary in magnitude and direction according to the localized contact dynamics with the rock face and rock particles in the hole. During events characterized by high tensile stress, cracks can form in the diamond layer. These cracks, being subjected to repeated high stress events, can propagate to form fracturing and spalling of the diamond layer. One region particularly susceptible to such occurrence is at or very near the diamond-carbide interface in the diamond layer. This region, in PDC's not of the present invention, suffers from pre-existing high residual tensile stresses which have previously been discussed. Advantageously, the cross-sectional profile depicted in FIG. 1 reduces the residual tensile stresses in the diamond or abrasive layer 12 in precisely the region where spalling or delamination occur most frequently, even as the wearplane progresses well into the compact. There are many ways in which the angled cross-sectional profile depicted in FIG. 1 can be implemented in an industry compatible disc shaped abrasive compact. FIG. 2 depicts one such embodiment. FIGS. 3, 4 and 5 present top and cross-sectional views of three other such exemplary embodiments. FIG. 3 shows a PDC 10b wherein the top ridge 15 of the contour is linear, forming a chord of the circular compact. In this case the sloping contour is a plane extending from cutting edge 25 to top ridge 15. FIG. 4 depicts a PDC 10c having a single concentric sloping contour which forms the entire abrasive/substrate interface. FIG. 5 depicts a PDC 10d having a sloping concentric contour according to the invention wherein the sloping interface intersects the top surface, resulting in a top zone which is made of substrate 11 which is outside the useful portion of the compact. Other embodiments, such as one based on a spirally shaped pattern of slopes, are also possible. While the invention has been described with reference to the presently preferred embodiments thereof, it is understood that the scope of the invention shall be limited only in accordance with the following claims.	An abrasive tool insert comprises a cemented substrate and a polycrystalline diamond layer formed thereon by high pressure, high temperature processing. The interface between the substrate and the diamond layer comprises at least one angled profile wherein said profile slopes downwardly and outwardly toward the periphery of the insert.	1
INTRODUCTION This invention relates to games and more specifically to a bowling-like game played on an inclined board and on which an array of bowling pins is spotted, and a spinning top is used to topple the pins. Games of this type are shown in U.S. Pat. No. 3,178,184 dated Apr. 13, 1965 and German Patents Nos. 335,586 and 349,897 dated Apr. 7, 1921 and Mar. 10, 1922, respectively. In particular, this invention embodies improvements in both the top and the pin arrangement to increase the number of games which may be played and to increase the precision with which the top may be spun. In the pin and top bowling-like games shown in the prior United States and German patents, supra, a rectangular playing surface is provided with four legs, all of different height so that the board surface is gently inclined toward one corner. An array of pin spots is applied to the surface in the vicinity of the end of the board which includes the lowest corner. In the prior art, the board either bears a nine pin or ten pin array. The top is spun at the far end of the board, and the object of the game is to knock over either all or a selected number of pins with the spinning top as it proceeds lengthwise along the board. In the prior art, the games are scored as in conventional bowling. In accordance with the present invention, superimposed nine pin and ten pin arrays of spots are provided on the board surface, and the top is made with a special tip configuration. The superimposed arrays of spots suggest a variety of different ways in which the game may be played, and the special top tip configuration enables the player to cause the top to move along the board surface in one of several different configurations so as to increase the skill which may be employed in the play of the game. Thus, in accordance with the present invention a pin and top bowlinglike game is provided having greater versatility and affording the exercise of greater skill than the pin and top games of the prior art. BRIEF FIGURE DESCRIPTION FIG. 1 is a perspective view of the game board of the present invention, looking down upon the top surface. FIG. 2 is a perspective view of the game board looking upwardly from below the bottom. FIG. 3 is a fragmentary cross-sectional view taken along the section line 3--3 of FIG. 1. FIG. 4 is a plan view of the pin spot arrangement on the playing surface of the board. FIG. 5 is a side elevation view of the spinning top of the present invention. FIG. 6 is an enlarged fragmentary view of the tip of the top. FIG. 7 is a plan view of the top. And FIG. 8 is a side elevation view of one of the pins of the present invention. DETAILED DESCRIPTION The playing board 10 shown in FIG. 1-4 has a playing surface 12 surrounded by side rails 14 and 16 and end rails 18 and 20. In the preferred form of this invention the playing surface is approximately 15 inches wide and 25 inches long. The side and end rails are rabbeted along the bottom inner corner as shown in FIG. 3 to receive bottom panel 22 and glass sheet 24. Cushion-like strips 26 and 27 made of foam, felt, or some similar material are placed above and below the periphery of the glass 24 to protect its edges between the rails and the bottom panel, and the assembly is held together by a number of screws 28, as is evident in FIGS. 2 and 3. The smooth playing surface 12 of the board defined by the upper surface of the glass is an important characteristic of the invention. That smooth surface enables the top to spin smoothly on the surface in one of several paths as is described in greater detail below. Four legs 30, 32, 34 and 36 are located at the four corners of the board, cemented or otherwise secured to the lower surface of panel 22. As is evident in FIG. 2, leg 20 is the tallest, leg 32 is the next tallest, leg 34 is somewhat smaller than leg 32, and leg 36 is the shortest of all. In the embodiment shown, the shortest of the four legs 36 is made up only of the rubber foot 38 and does not include the blocktype of leg which is part of the leg structure at the other corners. Leg 30 is approximately 1/2 inch longer than leg 32, leg 32 is approximately 7/16 inch longer than leg 34, and leg 34 is approximately 5/8 inch longer than leg 36. This arrangement causes the surface 12 to slope gently toward the corner 40 as viewed in FIG. 1. In the preferred embodiment, the slope of the playing surface is approximately 3°-5° from the horizontal measured between side rails 14 and 16, and approximately 1°-2° between end rails 18 and 20. The bottom panel 22 as seen through the surface of glass sheet 24 bears starting area 50, foul line 52 and pin spot region 54 on its upper surface. The starting area which may be defined by a contrasting color or texture in the upper surface of panel 22 and covered by glass 24 has margin 56 spaced approximately 13/4 inches from rail 18, and the area is approximately 43/4 inches wide. The foul line 52 is approximately 2 inches from the edge 58 of the starting area. In playing the game, the spin of the top is initiated in the starting area 50, and the player may recall the top and spin it over again before it crosses the foul line 52 if for any reason the spin is not to his satisfaction. The pin spot region 54 as shown in FIG. 4 consists of 19 spots closer to side rail 14 and leg 32 than rail 16 and and corner 40. Contrasting colors of these spots identify two distinct geometrical patterns superimposed on each other. One array of spots is a ten spot arrangement in the configuration of an equilateral triangle in which each spot is equidistant from its neighboring spots, thus conforming to the standard ten pin setting pattern and allowing to play in minature a naturalistic bowling game to the exacting scoring rules of the alley games. Eight spots 60a to 60h are shown in FIG. 4 as clear single circles and the two spots 62a and 62b consist of two concentric circles with clear outer rings to identify their color coding. (Typically clear or unlined areas of the spots may denote a royal blue color.) The remaining nine pin array of spots, all bearing numeral 64, superimposes a square configuration on the triangular ten spot arrangement in such a manner that corner spot 64a of the square configuration in FIG. 4 locates in the center of the side of the triangle which is formed by spots 62a, 60g, 60h and 62b. The diagonal lines of the square formed by spots 64i, 64e and 64a, and by spots 64d, 64e and 64f respectively, are identical in length with the sides of the triangle. Each of the spots 64a through 64i consists of two concentric circles, and the cross hatched areas of all nine outer rings indicate their identical color coding. (For example, cross hatched outer ring areas may denote the color red.) The square arrangement of the nine spots 64a through 64i conforms to the regulation pin setting pattern of nine pin bowling, and the miniaturized game may be played to the exacting rules and score count of the alley game. Combining the spots 64a through 64i of the nine spot configuration of the square pattern with spots 62a and 62b of the triangular pattern, creates an eleven spot pentagonal array of spots, all of which bear inner dots with outer rings of contrasting colors. In this pattern, spots 62a and 62b form equispaced four spot lines with spots 64g, 64e and 64c and with spots 64h, 64e and 64b respectively. The eight spots 60a through 60h which are shown clear in FIG. 4 and may be solid royal blue in this example, show a distinct eight spot pattern for another pin game, and the spots 60b through 60h form a distinct equispaced hexagonal seven spot pattern for still another pin game. The top shown in FIGS. 5-7 is composed of a body 70, spinning shaft 72 and tip 74. The periphery of the body 70 as shown in FIG. 7 is generally octagonal-shaped, and the periphery serves as the striking edge of the body intended to knock down the pins standing on the spots. The scalloped configuration of each side of the body increases the agressive character of the top, i.e., upon striking a pin a greater toppling force is applied than would be if the sides were straight. The configuration of the tip 74 is critical to enable the top to travel the various patterns described below. In the preferred form tip 74 has a flat or even upwardly dished area 76 at its center that extends to about a quarter of the tip diameter. The central area 76 is defined by a marginal edge 76' which engages the surface 12 of the board as the top spins. The central area 76 blends into a lens-shaped area 78 which in turn, via a minimum blend radius 79 merges into the conical part 80 of tip 74. In the preferred form, the flat or dished area has a diameter D' of 0.040 inch, the radius R is 0.280 inch and the tip diameter D" is 0.160 inch. If radius R and/or diameter D" are too large, the top will be unstable. This particular configuration enables the player to control the spinning top so that it follows any one of three basic types of projectories across the board surface from the starting area toward the pin region 54. Depending upon the force of the spin and the angle of the top with respect to the board, the top may be made to follow either a straight line course which tends to climb toward the higher side rail 14 of the board as suggested by line 90, a scallopedlike course which tends to remain parallel with the side rails 14 and 16 as suggested by the line 92, or a looped course which tends to fall off toward the lower side rail 16 as the top travels from the starting area 50. The looped path is suggested by line 94. If the top tip 74 did not have either the flat or upwardly dished center 76 but rather came to a point or otherwise had a surface engaging area of minimum diameter, (substantially point contact with the playing surface) the top would not readily travel along the board, but would tend to stall in one location or drift in the direction of the fall line of the board. It would not be possible accurately to control the travel of the top. The curved region 78 of the tip is essential to enable the top to travel either the scalloped or looped paths suggested by lines 92 and 94. Thus, the special tip configuration and the sloping board surface cooperate to make the game one involving very considerable skill. It is not merely a game of chance. In FIG. 8, one of the pins is shown. All of the pins may conform in shape to the one illustrated or alternatively some pins may be different than the others in shape and/or color. The pin shown includes a head 100 and a cylindrical barrel 102 connected by a narrow neck 104. The diameter of the barrel 102 is slightly reduced at its bottom by a chamfer 106 to a diameter substantially equal to the diameter of the spots in area 54. To avoid pins sliding off position on minor impact with tumbling pins or the top, the bottom surface 108 is coated with a high friction material 110 such as rubber or plastic. The center of gravity of the pin is such that it is stable in position on a spot unless struck by another pin or by the top with substantial impact. The several pin patterns coupled with the different color combinations of the spots lend themselves to a variety of different games that can be played on the board. Quite obviously, by using the ten pin array conventional rules of scoring of the American Bowling Congress can be followed. Similarly, by using the nine pin array the game can be played in accordance with the rules of the Federation Internationale Des Quilleurs. And seven and eight pin games may be played by using the clear single circle spots 60a-60h, with or without spot 60a. In addition, the eleven pin array can be utilized for a variety of additional games. For example, different pins may be given different point values and consideration can be given to the particular pins which remain standing and/or the sequence in which they fall as well as to the number which have been toppled. In addition, the colors of the central dots or circles exposed by toppled pins can be taken into consideration in scoring the game. For example, in the spot array shown in FIG. 4, the color of the center dot is the same in the five spots 64a, 64d, 64f, 62a and 64i (typically yellow). The color of the center dot of spots 64b, 64e and 62b is another color (typically orange). And the remaining three spots 64c, 64g and 64h have three different colored center dots (typically light blue, green and white). Thus, five different colors are available and each can be accorded a different scoring point factor. From the foregoing description it will be appreciated that the game of this invention has a great deal of versatility in that it allows a variety of games to be played. The pins and spots together may contribute to the scoring. And the particular configuration of the top tip and surface slope enable players to impart different types of motion to the top in travelling from the starting area to the pins. Because departures from the embodiment shown will occur to those skilled in the art upon reading the foregoing specification, it is not intended that the breadth of this invention be limited to the specific embodiment illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.	A bowling-like game played with pins and a spinning top on an inclined board surface. An array of spots is marked adjacent one end of the board and a starting area is marked at the other end of the board. The spots are coded to indicate a variety of different pin arrangement and provide for a variety of different scoring techniques. Thus, the spots as well as the pin fall may contribute to the scoring. The tip of the top is specially shaped to enable a player to direct the top in any one of several courses.	0
This application is a division of Ser. No. 09/328,953, filed Jun. 9, 1999 now U.S. Pat. No. 6,379,136 B1. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a new sub-denier spunbonded nonwoven web product produced by a unique spunbond apparatus and its unique operating process for the continuous production of thermoplastic synthetic resin filaments at unusually high filament speeds. More particularly the invention relates to the production of such nonwoven webs by this spunbond apparatus utilizing extremely high fiber speeds, generally of the order of 80 m/sec and more typically exceeding 100 m/sec. resulting in fibers on the order of 1.0 denier and less. In another important aspect, the invention relates to a nonwoven fabric possessing a more uniformly random web structure with sub-denier fibers created by the inventive apparatus and method. This web structure results in a narrower ratio of machine direction to cross direction tensile properties in addition to significantly improved cover and greater opacity. 2. Prior Art It is well known to produce nonwoven webs from thermoplastic materials by extruding the thermoplastic material through a spinneret and drawing the extruded material into filaments by eduction to form a random web on a collecting surface. U.S. Pat. No. 3,802,817 to Matsuki et al describes a full width eductor device and method which requires high pressures, however it is limited to lower speeds for practical operation. U.S. Pat. No. 4,064,605 to Akiyama et al similarly describes apparatus employing high speed air jet drafting with the same inherent limitations. U.S. Pat. No. 5,292,239 to Zeldin et al discloses a device that significantly reduces turbulence in the fluid flow in order to uniformly and consistently apply the drawing force to the filaments, which results in a uniform and predictable draw of the filaments. This system limits the magnitude of attenuation because of insufficient draw forces due to the extremely shallow jet angle. U.S. Pat. No. 5,814,349 to Geus et al discloses a device which combines quench fluid flow with below the belt suction. However, this arrangement requires a decoupling device in order to prevent skein forming deceleration which negates the original advantages of the U.S. Pat. No. 5,032,329 to Reifenhauser. Polypropylene is the only thermoplastic resin that is commonly utilized in conventional air drawn spunbond processes. It is important to note that due to the limitations of existing spunbond spinning systems it is virtually impossible to process resin entities in equipment designed for polypropylene where flow and spinning characteristics deviate significantly from polypropylene. As a first step, the resin is melted and extruded through a spinneret to form a vertically oriented cascade of downwardly advancing molten fibers. The filaments are fluid cooled to quench and uniformly cool the filament curtains for optimum drawing and development of the desired high crystallinity which provides the goal of high fiber strength. A fiber drawing system having a fluid draw jet-slot, into which a controlled volume of high velocity fluid is introduced, draws additional fluid into the upper open end of the drawing slot and creates a rapidly moving downstream of fluid within the slot. This fluid stream creates a contiguous drawing force on the filaments, causing them to be attenuated. After the filaments are attenuated they exit the bottom of the slot where they are deposited on a moving conveyor belt to form a continuous web of the filaments. The filaments of the web are then joined to each other through conventional calendering and point bonding techniques. Forming filaments in the well known conventional spunbond systems results typically in filaments of 2.5 denier to 12 denier and higher. Using conventional methods, the molten filaments leaving the spinneret typically are immediately cooled at their surfaces to ambient temperature and then subjected to the typical drawing system. This conventional method and apparatus produce adequate non-woven fabrics however their properties, especially tensile strength, high machine direction to cross direction strength ratio, non-chemically enhanced hydrophobicity, drape, softness and opacity are poor. When conventional spunbond systems attempt to make sub-denier fiber the resin output per hole drops precipitously reducing spunbond fabric production to less than half of the production when forming spunbond of typical denier range. The instant invention through the use of a unique new apparatus and process, provides a greatly improved spunbond fabric consisting of a narrow range of low denier filaments which improves all of the aforementioned properties. The low-denier filaments with their smaller diameter produces more surface area and more length per unit weight, reduces light transmission and improves light dispersion (greater opacity) and softness (lower unit fiber deflection forces). Using the instant invention spunbonded fabrics can be made from a wide range of resins, in addition to polypropylene, such as polyethylene, polyester, polyamides, polycarbonate, polyphenylene sulfide, liquid crystal polymers, fluropolymers, polysulfone and their copolymers as well as other extrudable synthetic resins. Providing narrow ranges of filament sizes from 0.1 denier to 1.0 denier with a wide range of polymers is extremely desirable because of their improved performance properties as indicated above. A further process benefit of the instant invention is that resin throughput per hole per minute is not reduced below existing commercial rates. Examples of end uses for the instant invention are filtration materials, diaper covers and medical and personal hygiene products requiring liquid and particulate barriers that are breathable and provide good vapor transport with significant air permeability. Because of the low denier the spunbond fabrics produced by the instant invention have physical and performance properties comparable to SMS (Spunbond-Meltblown-Spunbond), SMMS (Spunbond-Meltblown-Meltblown-Spunbond) and SM (Spunbond-Meltblown) fabrics. This is an important result since it suggests that a single die head or beam can produce a material which now requires from two to four die beams. Prior conventional spunbond art is almost completely concerned with the use of polypropylene. An important limitation of prior art is the inadequacy of conventional spunbond systems to extrude and highly draw common resins such as polyester, polyethylene or more unusual resins such as polyamides, polycarbonate, polysulfone and polytetrafluoroethylene. The instant invention teaches apparatus and processes that are designed with intrinsic accommodations to extrude and draw fibers with an extreme range of extrusion temperatures, wide variations in glass transition temperatures, wide ranges of melt viscosities and other variable resin properties important to filament extrusion, forming, quenching and drawing, thereby widening the application of the spunbond arts. OBJECTS OF THE INVENTION It is the principal object of the present invention to provide an improved system for the production of spunbonded nonwoven webs of thermoplastic synthetic resin filament which allows: 1. significant increase in filament velocity and attenuation over a wide range of filament diameters. 2. significant decrease in fiber denier or diameter at lower operating costs without sacrificing mass through-put. 3. capability of spunbonding a wide variety of resins using one apparatus having a wide degree of adjustment in the extrusion, forming, quenching, drawing and laydown operations. 4. stronger fibers through improved crystallization kinetics based on improved attenuation and quench control. 5. higher nonwoven fabric opacity and cover. 6. increased fiber and nonwoven fabric uniformity (narrower filament diameter range). 7. significant increase in collector speeds with resultant higher mass throughput. 8. production of webs with filament deniers of less than 1.0. 9. production of light weight webs at collector speeds in excess of 600 meters per minute. 10. production of nonwoven material at mass rates of greater than 400 to 600 kg/hr/meter of die width. 11. Filament spinning speed of greater than or equal to 7000 meters/minute. More specifically, it is an object of the invention to improve a spun-bond apparatus so that the throughput of the synthetic resin filament is increased and the production rate enhanced without encountering drawbacks typically found in spunbond apparatus such as excessive energy consumption and poor web uniformity. Other important objects of the invention are to provide: 1. an improved method of operating a spunbond apparatus to eliminate drawbacks thereof by increasing the degree of attenuation while decreasing the filament denier at relatively low energy cost with a minimum of process complexity. 2. an improved method of feeding precise amounts of resin to each orifice in the spinnerets using multiple feeding mechanisms. 3. an improved filament extrusion die with the capability of containing a greater number of extrusion orifices per meter of die width and length. an improved apparatus for the purposes described which allows the operating conditions within the apparatus to be varied in a sufficiently wide range of relationships to accommodate a large variety of resin materials and for the production of a wide range of products without the limitations characterizing earlier and present spunbond production systems. 4. improved quenching performance and uniformity by precise control of fluid temperature and velocity in a plurality of descending zones of the quench fluid system. 5. an improved apparatus including a fluid inlet infuser, a draw jet-slot, a draw jet-nozzle, a venturis, and a outlet fluid diffuser which are independently adjustable to provide optimum process control over a broad range of resins. 6. an improved apparatus and process which increases the drag force on fibers by inducing a controlled sinusoidal fiber track which permits the fiber velocity to be increased by increasing the area of fiber exposed to the drafting fluid drag forces thus significantly reducing the filament denier and decreasing energy requirements. 7. an improved apparatus and process which provides controls induction of fluid into the draw jet slot extension below the venturi to induce mini-vortices at the walls and provide a turbulent boundary layer. 8. improved uniformity of filament laydown by controlled turbulent separation of the fiber cascade at the entrance to the lower adjustable fluid volume control diffuser. 9. an improved method of making nonwoven webs of synthetic resin filaments whereby drawbacks of earlier and present conventional spunbond systems, especially limitations on draw force, fiber velocity, fiber formation and web collector speed are eliminated. All of the aforementioned process and product improvements are an integral result of the system which is presented below. SUMMARY OF THE INVENTION An apparatus for the production of sub-denier spunbonded nonwoven fabrics has, according to the invention, a resin extrusion device, a unique multi-head metering system for micro-metering resin to micro-distributors in the spinnerets, a spinneret die head with dual front and back perforated spinning sections, separated by a buffer section or quench fluid extraction zone having a lower density of perforations and in some embodiments no perforations, wherein the buffer section allows full and uniform penetration of quench fluid, for extruding a multiplicity of continuous thermoplastic strands that then descend through a two sided, multilevel quench system and thence through a fluid volume control infuser system, which meters quench fluid into or, if required by the process conditions, out of the filament drawing system. The quench fluid is supplied from a blower through one or more heat exchangers into a controlled three level manifold which permits flow rate and temperatures to be controlled independently into each segment of the quench cabinet. The dual spinning sections with the unique buffer zone or quench fluid extraction zone located between the two outside spinning sections is a very important part of the instant invention because it permits the use of more spinneret orifices per meter of width than can be accomplished in conventional systems. This is accomplished by using a high density of orifices in the two outside spinning sections and a central fluid buffer zone or quench fluid extraction zone located between the two outside spinning sections. Experimentation with the design of the buffer zone indicated that it could also be used for the production of additional filaments without creating a disturbance in the filaments at the point of the two streams' impingement. We further found when the filament density, or orifice density, was about eighty percent or less of the filament density of the dual spinning sections that impingement of the opposing fluid streams in the buffer zone was not an issue. Consequently the central buffer zone may contain a reduced density of perforations, or in some embodiments, a zero density of perforations. This overcomes the necessity to significantly reduce resin flow per hole per minute which is the main drawback in producing low or sub-denier fibers at commercially acceptable rates. The end result of the flow reduction is that low denier fiber production is always reduced far below commercial expectations. Furthermore, inadequate control of the quench process results in ineffective drawing with resultant non-uniform and weak fibers. The bilateral nature of the split array orifice spinnerets with an independently controlled bilateral quench system also permits the use of two different but compatible resins, one on each side, or a differentially quenched bicomponent filament. The filament cascade is automatically guided into the filament drawing system by the fluid volume control infuser system which depends from the lower surface of the quench assembly and is extensibly attached to the draw jet assembly. The purpose of the fluid volume control infuser system is to conserve energy by using a portion of the quench fluid as part of the drawing fluid and simultaneously minimizing turbulence at the entrance to the draw slot thus providing a uniform cascade of filaments to the drawing step. This arrangement provides a self feeding action for the descending cascade of filaments and is extremely important from an operational standpoint. The fluid volume control infuser system consists of two perforated plates oppositely situated and variable, as to angle, open area and vertical length, each containing a multiplicity of uniquely shaped and oriented perforations to permit two-way fluid flow. Further, the open area of the multiplicity of fluid holes is controllable as to area by use of a slide gate or similar fluid volume control means. The holes or amount of open area controls the amount and pressure of fluid in the infuser and controls turbulence but allows the fluid to be automatically bled off or entrained. When quench fluid, descending from buffer zone, is drawn into the fluid volume control system infuser by its downward velocity and the suction developed at the inlet of the draw jet slot opening by the draw jet flow an over-pressure condition may occur which may cause turbulence at the slot inlet. The combination of the fluid scoop shape and the open area of the infuser plates permits the automatic shedding of excess fluid and the balancing of pressures as the fluid and filament velocities increase into the slot. The variable area permits the specific adjustment for different resin species where the quench fluid may be very high or low in volume and velocity. The major axis length of the perforated holes ranges from 10 millimeters to 100 millimeters. Each row may have different sized holes. The fluid scoop portion of the hole is elevated above the outer surface of the infuser plate. The infuser plates have a sliding means in their lower portion which permits the distance between the lower edge of the quench system and the upper surface of the draw jet assembly to be adjusted to required process conditions for different resin species. The filament drawing system consists of a draw jet assembly that contains a variable width draw jet-slot and variable width draw jet-nozzle. The assembly consists of a right and a left hand vertical halves. The right and left hand vertical halves are moveable horizontally in relation to each other. The entire draw jet assembly is moveable vertically in order to optimize the distance between the draw jet-slot and the emerging filaments at the spinnerets. The space between the left and right vertical halves defines the variable width slot used to vary drawing velocity. The upper surface of both the right and left hand halves of the assembly contains an adjustable nozzle plate that is moveable horizontally in relation to the slot wall and serves to define the variable width draw jet-nozzle outlet passage and thus adjusts the draw jet fluid velocity. The angle formed by the centerline of the primary jet-nozzle and the centerline of the draw jet-slot ranges from 2 degrees to 45 degrees. The slot extends vertically to the draw jet extension and horizontally the width of the spinneret head. The draw jet-nozzles formed by the adjustable nozzle plate and the upper edge of the vertical halves provide motive fluid for the drawing process, extend the full horizontal width of the jet-slot. Experimentation showed that when the two horizontally opposed and adjustable draw jet-nozzles are offset vertically by a centerline distance of from 1 millimeter to 50 millimeters the draw force is still very high but, surprisingly, a vertical sinusoidal oscillation is created in the descending cascade of filaments. The filaments produced with this innovation were significantly finer than when the jet-nozzles were directly opposed and not offset. The oscillation produces a higher filament drag coefficient and thus increase the energy transfer coefficient between the filaments and the draw jet fluid stream thereby increasing the fiber attenuation. Further experimentation showed that this oscillation could also be produced by several alternative methods. When a second set of adjustable gap jet-nozzles are located in the slot wall on each side of the left and right hand assembly halves and below the primary draw jet-nozzles, and when these secondary jet-nozzles are directly opposed and not offset, and are provided with a system that emits pulses of fluid at a fixed angle across the slot alternately from each side these secondary jet-nozzles also create a small sinusoidal oscillation in the filament cascade which provides a larger drag area for the motive fluid to impact and to accelerate the individual filaments. The angle formed by the center line of the secondary jet-nozzles and the centerline of the draw jet-slot ranges from 2 degrees to 45 degrees. The increased drag coefficient also provides a more efficient transfer of energy to the filaments. The secondary jet-nozzle may also suck fluid out of the draw jet-slot in the same alternating pulsation mode. It was also discovered that off-set pulsating jets also produced the required oscillations. Experimentation has also shown that the filaments may also be oscillated by a constant or intermittent flow from only one side. It was eventually discovered that the secondary jet-nozzle system worked best when they were offset and the flow was constant from each side. It was discovered that in the primary jet plus secondary jet configuration the additional fluid flow together with improved drag factor from the oscillation effect added an unexpectedly high velocity increment to the filament curtain which resulted in remarkably low fiber diameters which were in the 0.5 denier to 1.2 denier range depending on the system configuration. Adjustable gap secondary draw jet-nozzles were also evaluated and determined to provide even better control of denier. Both the primary and secondary jets are preceded by a full die width pressure equalization and distribution system. Below and attached to the lower half of the draw jet assembly is a supplemental acceleration device or draw jet slot extension, which has a horizontally adjustable slot similar to the draw jet assembly slot but which is also vertically adjustable and contains two in-line or tandem venturis or other fluid acceleration devices to maintain fiber tension and draw force through the lower end of the draw system. Alternative fluid acceleration devices such as a NASA profile convergent-divergent nozzle or other fluid acceleration means can also be used. The draw jet extension has an adjustable slot and venturi width to control draw velocity and maintain constant tension on the filament cascade. The draw jet extension's distance above the foraminous collector belt is also adjustable. Below each venturi is an additional set of adjustable inlet jets on both sides which may be used to suck in ambient fluid thereby creating a series of micro-vortices in the wall boundary layer. This creates a turbulence at the wall between the first venturi and the second venturi and after the second venturi prior to the exit into the fluid volume control diffuser system. The fluid volume control diffuser system consists of two perforated plates oppositely situated and variable, as to angle, open area and vertical length. The major axis length of the perforated holes ranges from 10 millimeters to 100 millimeters. Each row may have holes with different major and minor axis length. The fluid scoop portion of the hole is elevated above the surface of the diffuser plate. The plates depend from the bottom of the draw jet-slot extension assembly and which lower adjustable ends may be abutted to vacuum seal rollers or other sealing means, or open to the atmosphere. In the case where the plates are open to the ambient atmosphere the ends of the plates are adjusted to the correct distance above the foraminous belt. The distance of the two plate ends above the foraminous belt may be equal or unequal. Generally in the case where the ends of the plates are open to the ambient atmosphere the deposition of fibers is more uniform if the longer plate is on the up stream side in reference to the belt travel direction. These plates contain a multiplicity of fluid holes which are controllable as to total area by the use of a slide gate or other means. The holes or amount of open area controls the amount and pressure of fluid in the diffuser and controls turbulence but allows the ambient fluid to be automatically entrained. This has a beneficial effect on the uniformity of filament lay down by controlling the rate of deceleration of the filaments. The filaments begin to decelerate upon entry into the fluid control system and begin to describe a downward spiraling motion which assists in developing a uniformly isotropic web deposited on the foraminous conveyor belt used to receive and convey away the web. The fluid volume control system is adjustable as to the diffuser angle and open area. When the included angle between the two halves is wide the swirl approaches an elliptical appearance with the longer axis in the machine direction. Narrowing the included angle shifts the elliptical pattern to the cross direction. Proper angle and fluid flow adjustment of the fluid volume control diffuser is based on belt speed and required areal web weight so that the resultant swirl pattern on the moving belt is most nearly circular. A circular pattern provides the most isotropic product physical characteristics wherein the machine to cross direction ratios of physical properties such as tensile strength and elongation approach a ratio of 1:1. This is significantly better than typical spunbond fabrics which generally have ratios in the 2:1 or higher range especially at low areal weights and high belt speeds. The narrower ratio permits lighter weight fabrics to be safely used in applications such as disposable diapers where cross direction tensile strength is an important consideration from both the diaper manufacturing and end use requirements. In order to maintain complete and total control of the system fluid and also reduce the load on the under belt suction device it is necessary to prevent the incursion of ambient fluid into the space between the outlet of the diffuser system and the belt as well as between the belt and the plenum. This is accomplished by creating a sealing system where the lower end of each fluid volume control diffuser system plate assembly is affixed to a curved surface which is slidingly adjoined to a set of upper vacuum seal rolls. This effectively seals the control system against fluid being sucked in at the lower edges of the volume control system thus minimizing any possible turbulence which might interfere with filament lay down. The curved surface is designed such that surface is continually in sliding contact with the surface of the stationary vacuum seal rolls. regardless of the angle of the diffuser system. The curved surface or shoe is covered with a replaceable low pile fabric to aid in sealing. Alternatively the rolls may be covered with fabric. The two above the belt sealing rolls are paired with two below the belt sealing rolls in order to provide an essentially leak proof connection between the diffuser ends and the upper opening to the vacuum plenum. The lower sealing rolls are also slidingly sealed to the plenum. The lower or suction opening of the vacuum plenum is connected to a variable volume suction blower or other variable volume suction pressure device by a duct. To decrease the web thickness prior to the deposition of an additional web or the web bonding step it is compacted by a driven web compaction roll set directly after leaving the vacuum area. The variable speed foraminous collector screen or belt then delivers the web or multiple webs to a filament bonding station, such as thermal pattern bonding or other means of web bonding or interlocking. It is anticipated that this unique spunbond system will be used in combination with a meltblown system and a second unique spunbond system to provide a unique in-situ three web laminate. It is further anticipated that this unique spunbond system will be used in combination with a meltblown system to provide a unique in-situ two web laminate. It is further anticipated that using the instant invention, spunbond fabrics with average filament sizes below 0.7 denier will have, opacity, resistance to liquid penetration and other physical and performance properties comparable to SMS webs. Glossary of Terms In order to better understand the terminology used herein, particularly those terms which may be ambiguous with respect to some prior art or which have been indiscriminately used without explanation in the prior art, the following definitions are submitted. Aspirate: to draw by suction Aspirative means: a means by which an internal force such as a suction or differential pressure sucks or draws fibers or fluid through a passage or slot Buffer zone: see quench fluid extraction zone Capillary: refers to the resin extrusion orifice or any other drilled hole or perforation that serves as an orifice Crystallinity: the relative fraction of highly ordered molecular structure regions compared to the poorly ordered amorphous regions as determined by X-ray or other appropriate analytical means Die head: refers to complete structure containing the spinnerets, resin distributors and other associated filament extrusion equipment and which extends across the full width of the spunbond machine, also referred to as a die beam Diffuser: a diverging channel transition system for controlled reduction of the velocity of the fluid and filaments exiting the filament drawing system and entering the filament lay-down system Educt: to draw out Eductive means: a means by which an external force such as a suction fan creates a differential pressure that draws fibers or fluid out through a passage or slot Fluid volume control plate open area: the ratio of the actual area of the holes as precluded by the slide control plate to the total area of the fluid-scoop holes Induct: to bring in Inductive means: a means by which an external force such as a pressure fan creates a differential pressure that transports or brings fibers or fluid into or through a passage or slot Infuser: a converging channel transition system for controlled funneling of fluid and filaments into the filament drawing system Jet: a slot, nozzle, perforation or other orifice through which a fluid may be emitted or drawn in and which may have an opening that is round, rectangular, or any other shape without regard to length or diameter MD/CD ratio: ratio of a fabrics machine direction to cross direction properties typically used as a measure of isotropic formation Quench fluid extraction zone: That portion of the area between the quench cabinets where the bilateral quench fluid streams meet and descend into the fluid volume control infuser Resin: refers to any type of material that may be liquefied to form fibers or nonwoven webs including, without limitation, polymers, copolymers, thermoplastic resins, waxes, emulsions and the like BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which: FIG. 1 is a vertical cross section through one embodiment of the apparatus of the invention, FIG. 2 is vertical cross section through a second embodiment of the apparatus of the invention, FIG. 3 a is a plan view of a fluid scoop plate of the volume control system, FIG. 3 b is a side sectional view (X—X) of a fluid scoop plate of the volume control system, FIG. 4 a is a side view of a fluid scoop plate of the fluid volume control system showing the arrangement of the volume adjustment plate in the fully open position, FIG. 4 b is a side view of a fluid scoop plate of the volume control system showing the arrangement of the volume adjustment plate in the fully closed position, FIG. 4 c is a side view of a fluid scoop plate of the volume control system showing the arrangement of the volume adjustment plate in the partially open position, FIG. 5 is a detailed view of the supplemental draw jet slot extension and fluid acceleration devices, FIG. 6 is a detailed view of the supplemental draw jet slot extension, lower volume control plates, and lower volume control plates sealing system FIGS. 7A & 7B is a vertical cross section through the draw jet-slot assembly of the apparatus in detailed form. DETAILED DESCRIPTION The invention is described in connection with preferred embodiment, however it should be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the description as well as within the spirit and scope of the invention as defined by the appended claims. The apparatus shown in FIG. 1 generates a continuous spun-bond web from aerodynamically stretched filaments of a thermoplastic synthetic resin. Molten thermoplastic resin produced by an extrusion device (not shown) enters the inlets 1 to the pressurized fluid metering system 2 a , 2 c for distribution to the parallel micro-coat hanger distribution systems 3 a & 3 c . The pressurized fluid metering system is unique in that each pressurized fluid metering device has 2 or more individual outlets or in the instant case 6 outlets. Each individual pump outlet feeds an individual micro-coat hanger or three dimensional fluid distributor The micro-coat hanger distribution system systems 3 a & 3 c feeds the spinnerets 4 a , 4 c. A unique aspect of the micro-coat hanger melt extrusion distribution system is that each coat hanger is supplied resin from an individual feed supply and feeds only from 50 to 250 millimeters of die length. In the instant embodiment each coat hanger feeds 100 millimeters of die length. This insures precise control of the amount of resin reaching the filament extrusion orifices. Consequently the flow rate at each orifice is very consistent, and along with the other inventions that make up this process and its resulting web product, results in a very narrow range of filament diameters at a given set of conditions with a specific orifice diameter. The spinneret head with its dual spinning sections 4 a , 4 c , is separated by a buffer segment and quench fluid extraction zone. 5 . Two cascades of filaments 110 a , 110 c emerge from the discrete spinnerets 6 a, c and are contacted with quench fluid from the quench process fluid manifolds. The number of spinning orifices or capillaries per centimeter of cross directional die width is more than fifty percent greater than conventional spunbond dies. In the spinneret head 4 the space 33 between the two spinneret sections 4 a and 4 c provides a buffer zone 5 to prevent left and right side quench fluids from impinging on each other within the dense filament curtains descending from the two spinneret sections. It was previously discovered impingement of the opposing fluid streams in the buffer zone was not an issue if the filament density in the buffer zone was about eighty percent or less of the filament density in the dual spinning sections. The buffer zone can then, alternatively, be used to provide additional die holes in the spinneret. FIG. 2 shows the apparatus with a lower density spinning segment 4 b . The low density filament curtain 110 b is shown leaving discrete spinneret 6 b . Also shown is the additional pressurized fluid metering system 2 b , for distribution to the parallel micro-coat hanger distribution system 3 b . The capability to use more holes per meter of die width permits even higher overall throughput per meter and further reduces the loss of throughput when producing low and sub-denier fibers. The uniform quenching promotes an extremely narrow and uniform drawn filament diameter range. This is an important factor not present in the prior art. The buffer zone with and without the low density perforations also provides a non-turbulent turning region for the quench streams to combine and be entrained in the downward movement of the filament cascade. The quench fluid system which consists of two opposed assemblies of at least three individual manifolds zones 24 a, b & c , 25 a, b & c each of which operates at an individually controllable volume and temperature. The fluid volume and temperatures in each section may be controlled so that any temperature sequence, within the controlled range, may be attained thus, for instance, enabling a delayed quench or a warm annealing step to be followed by a cold quench. This is a necessary step in making high tenacity fibers from materials such as polyester or other materials with distinct glass transition temperatures (T g ). The opposed and separate nature of dual spinnerets and separately controlled bilateral quench also permits the use of two different but compatible resins, one on each side, or a differentially quenched bicomponent filament. The quench fluid is required for the solidification and crystallization process of each filament leaving the spinnerets 6 a , 6 b . In the instant invention each quench stream of the three quench fluid manifolds on each side delivers quench fluid at an individually controlled temperature ranging from 20° F. to 200° F. Each of the three quench fluid zones 24 a, b & c , 25 a, b & c is separately temperature controlled by temperature control means. The quench fluid is delivered to the unit by a pressurized fluid system which may have one or more blowers and one or more heat exchangers, each with its own pressure control allowing precise independent adjustment of the quench velocity within the range of 30 to 1000 meters per minute depending on the specific resin, mass throughput and other process requirements. After quenching, the filaments descend through an adjustable fluid volume regulation system or fluid volume control infuser system 17 which depends from the lower inner edges of the quench system to the draw jet-slot inlet 8 of the draw jet assembly 27 . The fluid volume control infuser system consists of two opposed specially perforated fluid regulation plates 19 as shown in FIGS. 3 & 4. The reversed fluid-scoop type perforations 14 permit excess quench fluid to automatically bleed off into the atmosphere based on the fluid pressure difference across the plate assembly. The major axis length of each perforation is from 2 millimeters to 150 millimeters. The open area of the adjustable specially perforated fluid regulation plates ranges from 5 percent open to 100 percent open. The preferred range is 20 percent to 80 percent. In the instant example open area was 60 percent. This is based on the total area of all the holes in the plate. Total open hole area can range from 10 percent to 70 percent of the perforated area of the plates. The holes are located in the upper portion of the plates. Up to 90 percent of the vertical height may be perforated. In the instant example the perforated portion was 80 percent. Each perforated plate's length is adjustable by a slide means 15 in the vertical direction in order to accommodate the relative changes in the distance between the lower surface of the quench system 16 and the upper surface 71 of the draw jet-slot assembly to which its lower edges are attached 18 . This angle can be between 20 and 120 degrees. The perforated plate 19 assemblies also contain a flat perforated slide valve plate 20 of FIG. 4, the perforations of which normally index with the reversed fluid-scoop type perforations of the fluid regulation panels which gives a full open system. Both lateral ends of the V-shaped channel created by the adjustable fluid regulation system are closed by an adjustable sealing means. The filament draw system FIG. 1 consists of a draw jet assembly 27 that contains a variable width draw jet-slot 9 and variable width draw jet-nozzles 29 a, b . FIG. 7 a and 7 b . The assembly consists of a right and a left hand vertical halves 25 a, b which are generally parallel. The right and left hand vertical halves are moveable horizontally in relation to each other by a screw adjuster system. The space between the left and right vertical halves defines the variable width draw jet-slot 9 used to vary drawing velocity. The variable jet-slot gap “S” FIG. 7 a , is adjustable between about 1.0 millimeter and 15 millimeters and is generally constant over the vertical length between the entrance and exit of the draw jet-slot. The draw jet assembly 27 extends vertically downward to the draw jet extension and horizontally the width of the spinneret head. The upper surfaces of both the right and left hand halves of the assembly 25 a, b contain moveable and precisely adjustable nozzle plates 26 a, b that are moveable horizontally in relation to the slot wall and serve to define the variable width draw jet-nozzles 29 a, b . FIG. 7 a shows the angle A formed by the center line of the primary jet-nozzle and the centerline of the draw jet-slot is 15 degrees. The draw jet assembly 27 is also moveable by a hydraulic, or screw jack system in order to adjust the distance between the spinnerets and the draw jet-slot entrance. The variable orifice jet-nozzles 29 a, b . formed by the adjustable nozzle plates and the upper edges of the vertical halves 25 a, b provide very high velocity motive fluid for the drawing process extend the full horizontal width of the draw jet-slot, which with the fluid pressure and temperature control of the variable pressure blower and heat exchanger provides precise regulation of the drawing fluid velocity and temperature. The angle A of the draw jet-nozzles, as shown in FIG. 7 a , with respect to the vertical has a broad range from about 5 degrees to about 60 degrees. The preferred range is 20 degrees ±8 degrees. In the instant example the angle is 15 degrees. The gap of the variable orifice jet-nozzles 29 can range from about 0.5 millimeters to about 6 millimeters. The tempered fluid is supplied to the draw jet-nozzle's inlets 7 a , 7 b of FIG. 7 a from the heat exchanger through a pressure equalizing distributor. The combination of precisely controlled quench fluid temperature and velocity permits each resin to be conditioned to the outer filament temperature required to optimize drawing in the slot and venturi sections. After drawing fluid velocity is established the two halves 25 a, b of the draw jet assembly 27 are adjusted to give the required jet-slot gap S of FIG. 7 a to optimize the motive fluid velocity in the slot. The distance of the surface of the draw jet assembly 27 from the lower surface of the spinnerets is adjustable from between about 400 millimeters and 1200 millimeters in order to maximize draw forces and filament attenuation which affect the reduction of filament denier and the increase in crystallinity. The vertical ends of the variable slot 9 are closed at their lateral or cross machine ends by an adjustable sealing means. As the filaments accelerate through the slot they pass between one or more opposed and offset secondary draw jet-nozzles 36 a, b of FIG. 7 a . The offset jets create perturbations across the slot 9 which induce a sinusoidal motion of the filaments which expose a greater surface area of the filament to the fluid stream. This creates a higher drag coefficient which transfers a higher amount of energy to the filaments creating a higher filament speed which improves the reduction of filament denier. The secondary jet-nozzles, which may also have an adjustable gap, are offset vertically 30 by a centerline distance of from 1 millimeter to 50 millimeters. In the instant example the offset was 20 millimeters. The angle “B” in FIG. 7 a formed by the centerline of the secondary jet-nozzle and the centerline of the draw jet-slot ranges from about 2 degrees to 45 degrees. The preferred angle of impingement ranges from 10 degrees to 20 degrees. In the instant case the angle was 15 degrees. A variable speed blower and heat exchanger supply the high pressure, temperature controlled fluid used to provide the motive force. Alternatively, one or more opposed secondary jet-nozzles 36 a , b. can be fed by high pressure fluid from a blower that has been sent to a variable speed rotating splitter (three way) valve (not shown) which alternates pressurized fluid between inlets 35 a, b . This provides alternate pulses between jets 36 a and b which also induces a sinusoidal motion of the filaments with a sharp increase in filament velocity. FIG. 7 a shows the angle B formed by the centerline of the secondary jet and the centerline of the draw jet-slot is 15 degrees in this embodiment. The broad range of the jet angle B formed by the centerline of the secondary jet and the centerline of the draw jet-slot, with respect to the horizontal axis, is from about +80 degrees to about 0 degrees. The secondary jet-nozzle gap 36 a, b range from about 0.5 millimeter to about 6 millimeters. An alternative method shown in FIG. 7 b for creating a sinusoidal motion of the filaments within the slot is to offset the variable primary jet-nozzles 29 a, b horizontal centerlines vertically 31 by between about 2.0 millimeters to about 20 millimeters as a broad range with 3.0 millimeters to 10 millimeters as the favored range. Filaments then enter the supplemental draw jet slot extension system 51 shown in FIG. 5 . The adjustable slot extension depends vertically downward from the lower surface of the draw jet assembly 27 , to which it is slidingly affixed to permit horizontal slot and venturi adjustment. The slot width of the draw extension is adjustable by means of a screw adjustment. The gap is adjustable between about 1.0 millimeter and about 15 millimeters and is generally constant over the vertical slot between the entrance and exit of the draw jet assembly. In the instant example the gap is 4 millimeters. This slot contains a first venturi 11 or other fluid acceleration means to further increase fluid velocity and prevent any loss of filament velocity in the system and maintain constant tension or increasing tension, on the filaments. The half angle of approach 57 to the venturi as shown in FIG. 5, ranges from about 1 degree to about 10 degrees whereas the half angle of recession 58 is from about 1 degree to about 12 degrees. In the preferred embodiment the angles are 3 degrees and 5 degrees respectively. The venturi gaps 52 _range from between about 1.0 millimeter and about 10 millimeters. The ratio of the venturi gap to the slot width in the draw jet extension ranges from about 0.95 to about 0.3. In the instant invention the venturi gap is 3 millimeters. After leaving the first venturi there is a set of adjustable inlet apertures 53 on both sides of the slot that are used to create a series of micro-vortices in the wall boundary layer. This creates a minor degree of turbulence in the boundary layer prior to the second venturi. Subsequent to the first set of adjustable inlet apertures 53 is a second venturi 12 or other fluid acceleration means to prevent any loss of filament velocity in the system thereby continuing to maintain tension on the filaments. The half angle of approach to the second venturi 12 ranges from about 1 degree to 10 degrees whereas the half angle of recession 41 is from 1 degree to 12 degrees in the preferred embodiment the angle are 3 degrees and 5 degrees respectively. This venturi is also variable in width. The second venturi gap 52 ranges from between about 1.0 millimeter and about 10 millimeters. The ratio of the venturi gap to the slot width in the draw jet extension ranges from about 0.3 to about. 0.95. Below the exit of the second venturi is an additional set of adjustable inlet apertures 54 on both sides of the slot that are used to create a series of micro-vortices in the wall boundary layer. This creates a minor turbulence in the boundary layer prior to the point at which the draw jet extension slot width increases due to the adjustable length means 56 and near the end of the draw jet extension immediately prior to the exit into the fluid control system. The slot extension's length is adjustable in the vertical plane by a sliding means 56 to accommodate the changes in elevation created by optimizing the distance of the draw jet assembly from the spinneret lower surface and optimizing the distance of the lower fluid control diffuser system from the surface of the collector. The width of the slot and venturi in the slot extension is also variable through horizontal adjustment means for further optimization of filament velocity. Depending from the lower slot extension is the adjustable fluid regulation system diffuser or volume control diffuser system which consists of an assembly of two opposed specially perforated fluid volume control plates FIG. 6 . Each perforated plate is adjustable by a slide means 15 in the vertical direction in order to accommodate the relative changes in the distance between the lower surface of the supplemental draw jet slot extension system 108 and the surface of the seal rolls 62 . The included angle of the perforated plates of the diffuser assembly is adjustable, by an adjustment screw from 10 degrees to 120 degrees, measured from the vertical axis, as required to optimize fiber lay down and maximize the formation of isotropic properties within the web. Adjacent and coterminous with the fluid-scoop type perforated plate 19 lies a flat perforated slide valve plate 20 , the perforations of which normally index with the fluid-scoop type perforations of the fluid regulation plates. Taken together they are referred to as the fluid volume control plate assembly. Lateral movement of slide valve plate 20 gradually occludes the air scoop perforations 107 and reduces the fluid flow in or out of the adjustable fluid volume control system diffuser as process operating conditions require. The purpose of the lower adjustable fluid volume control system is to permit ambient fluid to automatically bleed into the diffuser depending on the fluid pressure difference across the plate and simultaneously prevent turbulence at the exit of the draw slot while maximizing the randomness of filament distribution on the foraminous web collection system which will permit the formation of near isotropic physical properties within the web. The adjustment features of the diffuser also permit optimization of filament distribution and physical properties regardless of collector speed. The adjustable open area of the adjustable specially perforated fluid regulation plate assemblies ranges from 5 percent open to 100 percent open based on the total area of all the holes in the plate assembly. Total open hole area can range from 10 to 60 percent of the perforated area of the plates. The preferred range is 20 percent to 80 percent. In the instant example open area was 60 percent. The major axis length of each perforation is from 2 millimeters to 150 millimeters. The holes are located in the upper portion of the plates. The portion of the plate that is perforated ranges between 20 percent and 90 percent of the vertical height of the plate. In the instant example perforated portion was 80 percent. The lower end 61 of each fluid volume control diffuser system plate assembly 59 is affixed to a curved surface 60 which is slidingly adjoined to the upper vacuum seal rolls 62 and effectively seals the control system against fluid being sucked in at the lower edges of the volume control system thus minimizing any possible turbulence which might interfere with filament lay down. The curved surface 60 is designed such that surface is continually in sliding adjoinment contact with the surface of the vacuum seal rolls thus the rolls can remain fixed in horizontal position. The curved surface is covered with a replaceable low pile fabric to aid in sealing. A vacuum plenum 80 connected to variable suction pressure means is located beneath the surface of the variable speed foraminous collector screen 83 which runs between the upper 62 and lower 63 vacuum seal rolls. The two upper belt sealing rolls are oppositely and directly paired with two lower belt sealing rolls in order to provide an essentially leak proof connection between the diffuser ends and the vacuum plenum which is attached by duct to a controllable suction blower (not shown). The web is compacted by a driven web compaction roll set 84 & 85 after leaving the vacuum area. The variable speed foraminous collector screen or belt 83 then delivers the web to a filament bonding station, such as thermal pattern bonding or other means of web bonding or interlocking. PROCESS EXAMPLES The following experiments and the overall resultant data, as shown in Tables 1 through 6 below, demonstrate the intimate interrelationship between the apparatus, the process and the final spunbonded product. The compound and synergistic effects of the multiple draw jets, multiple venturis, fluid volume control infuser and diffuser on high speed attenuation and production of a unique spunbond material are shown in Table 1 in accordance with the process of the present invention. A one meter wide laboratory system with interchangeable central segments, one non-perforated and one with a 40% perforation density, was used for the following experiments. Using polypropylene with a 35 melt flow index the extrusion system and draw jet system was adjusted or modified to the various process conditions and settings shown in Tables 1, 2, 3, and 4. For those conditions not specifically shown therein the conditions and settings as shown in Table 5 were generally used. The process tests shown in Table 1 were run using both alternative die heads. No substantive differences were found between the 40% perforation-density central segment and the non-perforated central segment as far as process and product performance was concerned with the exception of the expected higher total throughput when using the 40% perforation-density central section. The first experiment, designed to evaluate component stage efficiency, was conducted by starting out with only the fluid volume control infuser assembly, the draw jet assembly, and the supplemental draw jet extension without venturis. Only the primary draw jet-nozzle or first draw jet-nozzle was used. In each subsequent experiment a different component of the invention was added and tested. Fiber velocities and filament diameters were checked for each experimental run. Each new component that was added was run at the same conditions shown in Table 5. The filament curtain extruding from the spinnerets was captured in the draw jet slot at an initial slot setting of 4 millimeters. This was gradually decreased to 2 millimeters to obtain minimum fiber diameter as determined by measuring fiber diameters using a microscope. Simultaneously with narrowing of the slot the draw jet assembly was elevated from its start-up position of about 1000 millimeters below the bottom of the spinneret to about 500 mm. The point was determined by spinning performance and minimum denier obtainable. These data were used as a baseline for further incremental testing of the remaining components. The next step was to turn on the secondary draw jet-nozzles. The secondary jet-nozzles were positioned 20 millimeters below the primary jet and one offset 3 millimeters. Fluid volume was increased until the denier was minimized. This step had the remarkable effect of increasing fiber velocity by 35 percent and reducing average denier by 32 percent. At this point a draw jet extension with one venturi was attached to the base of the draw jet assembly. After reaching process equilibrium fiber denier was optimized by making minor adjustments to the fluid flow of the primary and secondary jet-nozzles. The draw jet extension slot gap was set at 3.8 millimeters and the first venturi gap was set at 2 millimeters. Next, the single venturi draw jet extension was replaced with a dual in-line venturi draw jet extension. After reaching process equilibrium fiber denier was optimized by making minor adjustments to the fluid flow at the primary and secondary jet-nozzles. The draw jet extension slot gap was set at 3.8 millimeters and the primary and secondary venturi gaps were set at 2 millimeters. The data showed that there was a significant fiber velocity increase and corresponding significant filament denier decrease with the addition of each additional component. The total overall improvement compared to the base case fiber velocity was nearly 46 percent. The highest single component stage improvement was a 35 percent improvement between draw jets 1 and 2. This is believed to be primarily due to the greater horizontal cross-section filament surface area exposed to the drawing fluid due to the oscillation of the filament curtain and secondarily to the higher draw fluid velocity due to higher volume. The velocity increase between subsequent sections was smaller but the gross effect was an increase of almost 10 percent which resulted in a 4 percent decrease in denier. In further testing the sub-denier fabrics were examined for opacity and hydrophobicity. Both properties were found to be from 20 percent to 70 percent higher than the typical 14 gram per square meter spunbond fabrics because of the instant inventions greater uniformity cover and sub-denier fibers. Disposable diaper fabric was not used as the reference fabric in order to eliminate low hydrophobicity results caused by the addition of surfactants. The end product result using all of the draw line components was a very uniform 14 gram per square meter web having an average filament denier of 0.85, excellent fabric tenacity, greatly improved hydrophobicity and excellent opacity. Output of resin was in excess of 0.9 grams per hole per minute at an average denier of 0.85 and in excess of 1.2 grams per hole per minute at an average denier of 0.98. TABLE 1 Effect Of Drawing Section Apparatus Components On Fiber Velocity And Denier Run # 1 2 3 4 5 Components used Infuser Infuser Infuser Infuser Infuser Draw jet 1 Draw jet 1 Draw jet 1 Draw jet 1 Draw jet 1 Draw jet 2 Draw jet 2 Draw jet 2 Draw jet 2 Venturi 1 Venturi 1 Venturi 1 Venturi 2 Venturi 2 Diffuser Fiber velocity @ ext. exit (M/min.) 4900 6600 6800 6950 7150 Fluid to Fiber Velocity Ratio 3.2 2.5 2.4 2.4 2.3 Velocity increase from prior stage % 34.7 3.0 2.2 2.9 Total Fiber Velocity Increase 45.9 (Runs 1 to 5) % Filament Denier Average 1.36 0.90 0.88 0.87 0.85 Fabric Weight (g/M 2 14 14 14 14 14 Fabric Tenacity MD 51 48 49 48 48 Fabric Tenacity CD 45 43 42 41 42 Relative Opacity (% greater than) 24 42 43 44 51 (compared to 2.5 denier 14 gsm commercial SB) In a second test series data was gathered on the effect of diffuser open area and diffuser angle settings on the spunbond uniformity as measured by MD/CD strength ratios. Testing was done at three different collector belt speeds. The volume control diffuser system plate assembly angles were set between 10 degrees and 40 degrees with a collector belt speeds of 300 meters to 600 meters per minute. Diffuser open area was varied between 30 percent and 70 percent. Diffuser plate assembly vertical length was 500 millimeters. All other process conditions and settings were either maintained or slightly adjusted through the test sequences. The resultant data is shown in Tables 2, 3 & 4. The results showed that by changing the diffuser a surprisingly effective control was achieved over the deposition pattern of the filaments exiting the draw jet extension. By changing the angle of the diffuser's fluid volume control plates and their amount of open area the machine direction to cross direction ratio (MD/CD ratio) of fabric tensile strength can be altered to meet whatever ratio is required. In most cases a ratio of about one to one (1:1) is desirable. However in some case where higher cross direction strength is desirable, such as disposable diaper cover sheet, this can also be accomplished. A further experiment was done using a commercial polyester having an intrinsic viscosity of 0.64. The results, shown in Table 6, showed that fiber denier was greatly reduced. Fabric uniformity as measured by MD/CD tensile properties showed improvements similar to the polypropylene data. TABLE 2 Effect of Diffuser Angle Settings On MD/CD Ratio @ 300 M/min. Belt speed Run Number 1 2 3 4 Spinning speed (M/min) 6000 6000 6000 6000 Diffuser angle (degrees) 10 20 30 40 Diffuser Opening @ 88 176 268 364 Belt (mm) Belt Speed (M/min) 300 300 300 300 DOA* MD/CD MD/CD MD/CD MD/CD 30 0.18 0.44 1.36 2.47 50 0.27 0.70 2.11 3.12 70 0.53 0.95 2.51 3.62 Diffuser Open Area As % of Total Available Open Area Tensile Strength Ratio MD/CD TABLE 3 Effect of Diffuser Angle Settings On MD/CD Ratio @ 450 M/min. Belt speed Run Number 5 6 7 8 Spinning speed (M/min) 6000 6000 6000 6000 Diffuser angle (degrees) 10 20 30 40 Diffuser Opening @ 88 176 268 364 Belt (mm) Belt Speed (M/min) 450 450 450 450 DOA MD/CD MD/CD MD/CD MD/CD 30 0.23 0.97 1.95 3.08 50 0.52 1.45 2.60 3.44 70 1.03 1.88 3.27 4.23 Diffuser Open Area As % of Total Available Open Area Tensile Strength Ratio MD/CD TABLE 4 Effect of Diffuser Angle Settings On MD/CD Ratio @ 600 M/min. Belt speed Run Number 9 10 11 12 Spinning speed (M/min) 6000 6000 6000 6000 Diffuser angle (degrees) 10 20 30 40 Diffuser Opening @ 88 176 268 364 Belt (mm) Belt Speed (M/min) 600 600 600 600 DOA MD/CD MD/CD MD/CD MD/CD 30 0.41 1.33 2.37 3.35 50 1.09 2.18 3.14 4.12 70 1.67 2.65 3.76 4.83 Diffuser Open Area As % of Total Available Open Area *Tensile Strength Ratio MD/CD TABLE 5 General Process Settings Polymer Type PP PET Polymer Viscosity 35 MF 0.64 IV Polymer Melt Temp. ° C. 225 325 Polymer Throughput kg/hr/M 340 to 460 340 to 460 Orifices per meter of width Number 6200 6200 Metering Pump Streams Number 16 16 Quench Fluid Temp. #1 ° C. 7 8 Quench Fluid Temp. #2 ° C. 9 8 Quench Fluid Temp. #3 ° C. 12 8 Quench Fluid Volume #1 M3/min 15 34 Quench Fluid Volume #2 M3/min 7.5 17 Quench Fluid Volume #3 M3/min 7.5 17 Quench Fluid Volume Total M3/min 30 68 Upper Control Plates Angle Degrees. 30 42 Control Plates Hole Size mm 30 30 Control Plates % Open % 30 to 70 50 to 90 Primary Draw Fluid Volume M3/min 38 46 Primary Draw Fluid Pressure Bar 1 to 3 1 to 3 Draw Fluid Temp ° C. 15 to 30 15 to 30 Primary Jet-nozzle Gap mm 0.5 to 3 0.5 to 3 Primary Jet-nozzle Angle Degrees. 15 15 Secondary Jet-nozzle Gap mm 0.5 to 3 0.5 to 3 Secondary Jet-nozzle Angle Degrees. 15 15 Secondary Jet Fluid Volume M3/min 10 10 Draw Jet-slot Gap mm 2 to 8 2 to 8 Extension Slot Gap mm 2 to 8 2 to 8 Extension Venturi #1 Gap mm 1.5 to 4 1.5 to 4 Extension Venturi #2 Gap mm 1.5 to 4 1.5 to 4 Lower Control Plates Angle Degrees. 10 to 40 10 to 40 Control Plates Hole Size, diameter mm 30 30 Control Plates % Open % 10 to 80 10 to 80 TABLE 6 Effect Of Drawing Section On Polyester Run # 17 Components used Infuser Draw jet 1 Draw jet 2 Venturi 1 Venturi 2 Diffuser Fiber velocity @ ext. exit (M/min.) 7600 Fluid to Fiber Velocity Ratio 2.1 Filament Denier Average 0.85 Fabric Weight (g/mm 14 Fabric Tenacity MD 77 Fabric Tenacity CD 62 While preferred embodiments of the present invention have been described in the foregoing detailed description the invention is capable of numerous modifications, substitutions and deletions from the embodiments described above without departing from the scope of the following claims.	A unique isotropic sub-denier spunbond nonwoven product created by an apparatus and method comprising a unique multi-head resin metering system, a spinneret head with spinning sections, separated by a quench fluid extraction zone, a two sided, multilevel quench system, a fluid volume control infuser system which automatically guides the filaments into the filament drawing system while conserving energy by using a portion of the quench fluid as part of the drawing fluid and also minimizing turbulence at the entrance to the draw slot. The filament drawing system comprises a draw jet assembly with adjustable primary and secondary jet-nozzles and a variable width draw jet-slot. The entire draw jet assembly is moveable vertically for filament optimization. The offset, constant flow secondary jet-nozzle system provides an unexpectedly high velocity increment to the filaments by oscillating the filaments and increasing their drag resulting in remarkably low fiber denier on the order of 0.5 to 1.2. The apparatus also embodies a draw jet extension with an adjustable slot and contains two in-line or tandem which are also adjustable and maintain fiber tension and draw force through the lower end of the draw system. Drawn filaments are decelerated in an adjustable fluid volume control diffuser system which controls the amount and pressure of fluid in the diffuser and controls turbulence. The filaments enter into the fluid control system and begin to describe a downward spiraling motion results in remarkably uniform isotropic web where the machine to cross direction ratios of the bonded web physical properties such as tensile strength and elongation approach a ratio of 1:1.	3
BACKGROUND OF THE INVENTION The present invention relates to wall systems in general, and more particularly to a wall system which has pronounced sound absorbing, heat insulating and fire retarding properties. Still more particularly, the present invention relates to a wall system which may be used either as a permanent, a temporary or a slidable partitioning wall. Various wall systems are well known in the building industry and they have found widespread application. One of the main requirements for such systems is that they have good sound absorbing, heat insulating and fire retarding properties, whether such wall systems are used as permanent parts of the building structure, as dismountable partitions or as slidable partitioning walls. However, these requirements are not fully met even if the wall system is a solid masonry wall made of sound-absorbing and thermally insulating fireproof material; these requirements are even more difficult to meet in relatively thin partitioning wall systems. This results from the fact that the walls are at least partially permeable to sound and/or heat due to the immediate or mediate connection between the two opposite major surfaces of the wall facing the compartments being separated from one another by the wall or, in case of an outside wall, one of the surfaces facing the exterior of the building. Attempts have already been made to reduce the permeability of wall systems to pentration of sound and heat therethrough by providing a hollow insulating space inside the wall system which effectively separates one wall portion facing one of the compartments from another wall portion facing the other compartment or the exterior of the building. As a result of this arrangement, the heat and sound transmission through the wall system has been significantly reduced since the heat and sound conduction occurs predominantly through connecting portions or elements of the wall which bridge the hollow space and connect the two major wall portions to one another. Since these connecting portions or elements have a relatively small cross-sectional area, the heat and sound conduction therethrough is insignificant when compared to that of a solid wall but not negligible. In fact, the amount of heat and the intensity of sound penetrating through such hollow wall are still substantial. While the temperature drop between two neighboring compartments may be small so that the heat insulating properties of the wall system may not be of real significance in some wall systems, particularly in partitioning wall systems erected inside a building, the problem of sound penetration is to be avoided in such wall systems whether they are used as exterior or as partitioning walls, and particularly in the latter case. There are also already known wall constructions or systems in which two independently supported wall panels are provided which have neither immediate nor mediate contact with one another. However, these systems have up to now been utilized only for erecting permanent or at most dismountable partitioning or other walls, not for slidable partitioning walls. In addition thereto, all the parts of which the wall system of this type is to be assembled have to be transported separately to the building site. Consequently, the erection of such a wall system requires utilization of highly skilled labor force and involves considerable time expenditure. Consequently, it would be advantageous to mount a pair of wall panels on a shared supporting frame to form a wall element since then the erection of a partitioning wall would only involve arranging a plurality of such wall elements in mutual alignment and interconnecting the same; however, all of the heretofore known wall elements of this type have invariably involved formation of bridges between the two associated panels mounted on the same frame, with attendant deterioration of the sound and heat insulation properties of the wall due to the fact that the two panels are mounted on the same supporting columns or transverse beams which together form the frame. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to avoid the disadvantages of the prior art wall systems. More particularly, it is an object of the present invention to provide a composite wall element to be used in a wall system which has excellent sound absorbing, thermally insulating and fire retarding properties. It is a further object of the present invention to provide a wall element comprising two wall panels mounted on a shared frame. It is an additional object of the present invention to provide a wall element which may be moved as a unit and easily and reliably connected with another wall element to together form a wall system. It is a concomitant object of the present invention to provide a wall element comprising two wall panels mounted on a shared frame without immediate connection of the two panels to one another. It is yet another object of the present invention to provide a wall element which can be used either as a part of a stationary partition wall or in a sliding wall. In pursuance of these objects and others which will become apparent hereinafter, one feature of the present invention resides in providing a wall element having a frame made of metallic, synthetic plastic or similar material and having two upright supports on which two simple or composite wall panels are mounted in such a manner that each panel is supported at only one of the upright supports of the frame while it is spaced a certain distance from the other upright support on which the other panel is supported. Connecting elements are provided which connect the upright marginal portions of the two associated wall panels to one another and, when more than one of the wall elements are arranged next to one another in mutual alignment to form a wall system, to connect the marginal portions of the two adjacent wall elements to one another. In the latter case, the marginal portion of the panel of one of the wall elements which is spaced from the upright support abuts and is connected to the marginal portion of the adjacent panel of the other wall element which is supported on its associated upright support so that proper alignment of the wall panels and wall elements is assured. In a currently preferred embodiment of the invention, the panels of each of the wall elements are also mounted on the horizontal or transverse bars interconnecting the upright supports and forming with the latter the frame in such a manner that at least one gap is provided between the respective wall panel and the associated transverse bar, so that no heat or sound transmitting bridges are provided between the panels of the wall element and the frame thereof. According to the currently preferred embodiment of the invention, the connecting elements which connect the two panels of the wall element to one another and possibly also to the adjacent panels are made of sound-absorbing material so as to prevent transmission of sound from one of the panels of each wall element to the other one through the connecting elements. If the wall element has to have fire-retarding properties, the wall panels and the frame are made of fire-proof materials. The wall element or a plurality of interconnected wall elements according to the invention may either be used as a stationary, possibly dismountable partitioning wall or, alternatively, may be mounted for sliding on overhead or bottom rails in a conventional manner so as to provide a sliding door or a disappearing partitioning wall. The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of the wall element according to the invention with the front panel omitted; FIG. 2 is a side elevational view of the wall element according to the invention with the connecting elements omitted; FIG. 3 is a cross-sectional view of the wall system according to the invention comprising a plurality of interconnected wall elements of FIG. 1; FIG. 4 is a detail of the wall system illustrated in FIG. 3; and FIG. 5 is a cross-sectional view of the wall element according to the invention of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and firstly to FIGS. 1 and 2 thereof, it may be seen therein that a composite wall element according to the invention comprises a frame 1 which includes two upright supports 2 and 3 which are interconnected by transverse bars 4 and 5. The upright supports 2, 3 and the transverse bars 4, 5 may preferably be made of interconnected profiled metallic or synthetic plastic material sections of rectangular or similar configuration. Two wall panels 6 and 7 are mounted on the frame 1 in a manner which will now be described in detail with reference to FIGS. 3 to 5. As shown in FIG. 3, the wall panel 6 is composed of an outer plate 8 and an inner plate 10 which are made of conventional building materials such as wood, plywood, wood agglomerates, synthetic plastic materials or similar materials. If the wall system has to have fire retardation properties, then the material of at least the outer plate 8 is selected from a group of fireproof materials, such as plasterboard or asbestos. Similarly, the wall panel 7 is composed of an outer plate 9 and an inner plate 11. An intermediate layer 12 or 13 is provided between the outer plate 8 or 9 and the inner plate 10 or 11, respectively, the intermediate layer 12 or 13 being preferably made of synthetic plastic material and the plates 8 to 11 being attached thereto either by press-bonding or by any other conventional bonding or attachment method. The two wall panels 6 and 7 in the assembled condition of the wall element extend in mutual parallelism and spaced from one another in the direction normal to their major surfaces, thus defining with one another an enclosed space into which the frame 1 is accepted with clearance from each of the wall panels 6 and 7. A cushion member 14 is accommodated in the clearance between the panel 6 and the upright support 2, supporting the wall panel 6 on the upright support 2, while the panel 6 and the upright support 3 define with one another a clearance 15. In a similar manner, a cushion member 16 is accommodated in the clearance between the panel 7 and the upright support 3, supporting the wall panel 7 on the upright support 3, while the panel 7 and the upright support 2 define with one another a clearance 17. A connecting member 18 which is shown in greater detail in FIG. 4 is provided at each of the upright marginal portions of the wall panels 6 and 7 and comprises a preferably corrugated projection 19 which is accepted in and bonded to the intermediate layer 12 or 13. The connecting member 18 further includes a portion 22 which abuts the outer plate 8 or 9, respectively, and is provided with a recess 21 into which the inner plate 10 or 11, respectively, is accepted. A further projection 20 of the connecting member 18 extends into the enclosed space defined by the wall panels 6 and 7 and bounds a groove in which a retaining projection 23 is provided. A connecting element 24, which is preferably made of resilient sound-absorbing material, includes two hook-shaped projections 26 and 27 which respectively extend into the grooves defined by the projections 20 of the connecting members 18 associated with the panels 6 and 7, respectively so that the tips of the projections 26 and 27 engage the respective retaining projections 23. Alternatively, instead of providing two separate connecting elements 24 each being associated with one wall element, a shared connecting element may be provided having twice as many projections as the previously described connecting elements, each of the hook-shaped projections 26 or 27 engaging one of the retaining projections 23 of the four connecting members 18 associated with the two adjacent wall elements whereby the wall elements are interconnected. If the sound-proofing properties of the connecting elements 24 are to be further improved, the connecting elements 24 may be formed with hollows 25 reducing the cross-sectional area of the connecting elements 24. The connecting member 18 is further provided with a recess 28 adapted to receive an aligning member 29. When the two adjacent wall elements are brought together so that the marginal portions of the panels 6 or 7 of the two adjacent wall elements abut one another, then each aligning member 29 extends into the recess 28 of the connecting members 18 of the adjacent wall panels 6 or 7, respectively, thus aligning the panels 6 of the two adjacent wall elements with one another and similarly aligning the panels 7. Preferably, the aligning member 29 has such dimensions as to be accepted into at least one of the recesses 28 with pressure-fit so that, prior to assembling the two adjacent wall elements, the aligning member 29 is accepted into one of the recesses 28 and retained in it by friction. If the aligning member 29 is so configurated as to be received with pressure-fit into each of the cooperating recesses 28, this gives the wall system an increased stability and resistance to unintentional disengagement of the two adjacent wall elements. In order to prevent relative movement between the frame 1 and the wall panels 6 and 7, the cushion member 14 or 16 is accommodated between an abutment surface 32 of the respective connecting member 18 and an L-shaped section 30 which is rigidly connected to the inner plate 10 or 11 of the respective panels 6 or 7. The separate wall elements are assembled either in the production plant and transported to the building site in their assembled condition, or directly on the building site but preferably prior to erection of the wall system. The assembling operation includes inserting the cushion members 14 and 16 between the abutment surface 32 and the L-shaped section 30 provided on the respective panel 6 or 7 and introducing the upright supports 2 and 3, respectively, into the channels defined by the cushion members 14 and 16 or, alternatively, attaching the cushion members 14 and 16 to the uprights 2 and 3, respectively and inserting the cushioned upright supports 2 and 3 between the abutment surface 32 and the L-shaped section 30 provided on the respective panel 6 or 7. In this manner, the respective panel 6 is supported in cantilever fashion on the upright support 2 and the panel 7 is supported in cantilever fashion on the upright support 3. Subsequently thereto, the panels 6 and 7 are interconnected by the connecting elements 24 engaging the retaining projections 23 of the connecting members 18 so that the mutual distance of the panels 6 and 7 is set and so are the clearances 15 and 17 between the panel 6 and the upright support 3 and the panel 7 and the upright support 2. Then the aligning members 29 are inserted into the recesses 29 of the connecting members 18. When a wall system is to be erected from a plurality of such assembled wall elements, the first one of the wall elements is connected to the existing structure extending in the direction of the contemplated wall system, and each successive adjacent wall element is moved in its upright position toward the first wall element so that the aligning members 29 enter into the free recesses 28 of the connecting members 18. When the entire wall system is erected, then all the panels 6 of the various wall elements will be mutually aligned and also all the panels 7 of the various wall elements will be similarly aligned. It is evident that in the assembled condition no sound-transmitting or thermally conductive bridges are present between the wall plates 6 and 7 but for the sound-absorbing and thermally non-conductive connecting elements 24. Despite the fact that clearances 15 and 17 are provided between the respective upright supports 2 or 3 and the panels 6 or 7, the construction is extremely stable due to the fact that the two respective adjacent panels are interconnected by the aligning members 29 so that even the cantilevered upright marginal portion of the panels 6 or 7 is prevented from yielding, being mediately, via the aligning member 29, supported on the respective upright support 2 or 3 of the adjacent wall element. The above-discussed arrangement is quite satisfactory for permanent, immovable walls, even for those wall elements which are adjacent to the corners of the thus formed compartment where no adjacent wall element is available since the clearance 15 or 17 may be obtained by mounting the respective wall panel 6 or 7 to the existing structure. However, it is also possible for the corner wall elements, and imperative for end wall elements of a slidable wall, to provide a modified arrangement as illustrated in FIG. 3, in which an additional cushion member is provided between the otherwise cantilevered marginal portion of the wall panel 6 or 7 and the associated upright support 2 or 3. In other words, the clearance 15 or 17 is eliminated and replaced by the cushion member 14 or 16. It is evident that this expedient is necessary since otherwise there would be no support for the cantilevered marginal portion of the wall element, particularly such wall element which is used in a slidable wall. If so desired, sound-absorbing strips 33 may be accommodated in the recesses 28 which, when the slidable wall abuts the adjoining structure, provide sound and heat insulation between the two neighboring compartments. The strips 33 may be made of any sound-absorbing and thermally insulating material, felt being currently preferred. The two associated wall panels 6 and 7 of each wall element define with one another a relatively large enclosed space. This space may be, if so desired, filled either entirely or partially with insulating material 34 or 35, preferably with glass fibres or like materials. It is currently preferred that two separate insulating layers 34 and 35 are provided, each associated with one of the panels 6 and 7, so that a gap is provided between the respective layers 34 and 35. Coming now to the embodiment shown in FIG. 5, it may be seen therein that a different kind of insulating arrangement may also be provided in the regions of the upper and lower end faces of each wall element. In the currently preferred embodiment of the invention, the formation of heat and sound conducting bridges between the wall panels 6 and 7 is prevented even in these regions by providing gaps between the panels 6 and 7 and the transverse bars 4 and 5. The lower transverse bar 4 of the frame 1 is connected to the upright supports 2 and 3 or made in one piece therewith. An L-shaped section is connected to the transverse bar 4 and/or the upright supports 2 and 3 in a conventional manner, for instance by welding, and has an upright arm 38 and another arm 39 extending outwardly from the frame 1. A support rib 40 which may be either unitary with, or connected to, the arm 39 extends parallel to the arm 38. Another L-shaped section is also provided having an upright arm 41 accepted and retained between the outer plate 8 or 9 and the inner plate 10 or 11 and another arm 42 extending outwardly underneath the outer plate 8 or 9, respectively, and supporting the same. A U-shaped section 43 is attached to the inwardly directed side of the arm 41 so that the inner plate 10 or 11 is supported thereon and being provided with a downwardly directed groove having such dimensions that the support rib 40 surrounded by an insulating element 44, which may be made of foam rubber or similar material, is snugly received therein. When the rib 40 and the insulating element 44 are fittingly received in the groove of the section 43, the arms 39 and 42 of the two L-shaped sections are spaced from one another by a gap 46, and the arm 38 is spaced from the section 43 by a gap 45. As a result of the presence of the gaps 45 and 46 and of the insulating element 44, excellent sound and heat insulating properties are obtained. The upper transverse bar arrangement generally corresponds to the just described lower transverse bar arrangement with one exception, namely that the inner L-shaped section 47, 48 is mounted for movement in the vertical direction, instead of being rigidly connected to the frame 1. This particular arrangement includes a counter plate 49 connected to the arm 47 of the L-shaped section by connecting bolts 50 which are accepted in a vertical elongated cutout 51 of the transverse bar 4 so as to be movable between an upper position shown in the left half of the FIG. 5 and a lower position illustrated in the right half thereof. A support rib 52 corresponding to the previously described support rib 40 is provided with an insulating element 53, and a U-shaped section 54 is connected to the inwardly directed side of an arm 55, the section 54 and the arm 55 being similar to the previously described section 43 and arm 41. As a result of this arrangement, it is possible to arrange the panels 6 and 7 on the lower support rib 40 as previously described while the L-shaped section 47, 48 is in its upper position, and subsequently thereto also attach the panels 6 and 7 in the upper regions thereof by lowering the L-shaped section 47, 48 so that the support rib 52 with the insulating element 53 attached thereto is received in the groove of the section 44. The particular advantage of this arrangement is that the assembly of the wall section from the various components thereof, such as the frame 1 and the two wall panels 6 and 7, may be accomplished without any special tools. Consequently, it is possible to deliver the above-mentioned components to the construction site in their disassembled condition to be assembled in situ. Another advantage obtained by this arrangement is that any one of the panels 6 or 7 can be easily removed from the assembled wall element for repair purposes or in order to be exchanged for a different one. According to a modified embodiment of the invention, which is not illustrated, a shared U-shaped section may be provided instead of the two separate L-shaped lower sections of the two separate L-shaped upper sections. Of course, the lower U-shaped section would be rigidly connected to the frame 1, while the upper U-shaped section would be mounted on the frame 1 for movement in the vertical direction. In that case, of course, the panels 6 and 7 will have to be mounted simultaneously. The above-described wall element is particularly suitable for use as a sliding wall, either by itself or in combination with several other wall elements. Of course, in this event, suitable supporting sliding arrangement will have to be provided, which is well known in the building industry. Such arrangement may, for instance, include an overhead rail and a plurality of supporting rollers mounted on the wall element and adapted to travel on the overhead rail, or a bottom rail and a plurality of rollers provided underneath or laterally of the lower marginal portion of the respective wall element and adapted to roll on the bottom rail. Instead of providing separate rollers, they may be grouped in overhead or bottom carriages. Also, as an alternative, the lower rollers may be replaced by a layer of synthetic plastic material whose surface is relatively smooth and, consequently, whose coefficient of friction is relatively low, so that when the layer slides along the bottom rail, which may also be made of, or provided with a layer of, such low-friction material, the frictional resistance to the sliding movement of the wall element will be minimal. It wil be understood that each of the elements described above, or two or more together, may also find a useful application in other types of wall systems differing from the types described above. While the invention has been illustrated and described as embodied in a wall system, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.	A wall system comprises a plurality of supporting frames and a plurality of wall panels associated in pairs with each respective frame. The two panels of each pair are interconnected in the regions of their upright marginal portions so as to extend in mutual parallelism and to define a space in which the upright supports of the associated frame are accommodated with clearance from each of the panels. An insulating member is accommodated between one upright support and one of the panels, and another insulating member is accommodated between the other upright support and the other panel. The upright marginal portions of any two adjacent pairs of panels are interconnected in mutual alignment in such a manner that the insulating member associated with the upright support of one pair of panels is situated at the opposite side of the upright support from the side of the upright support of the other pair of panels at which the other insulating member is located so that mediate contact between the two panels of each pair is avoided without sacrificing the stability of the system. The upright supports of each frame are interconnected by transverse beams on which the pair of panels is supported with clearance. Additional rails and rollers may be provided when the wall system is to be used as a sliding partition.	4
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit of U.S. Provisional Application No. 61/182,060, filed on May 28, 2009, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present embodiments relate to compounds with physiological effects, such as the activation of hematopoietic growth factor receptors. The present embodiments also relate to use of the compounds to treat a variety of conditions, diseases and ailments such as hematopoietic conditions and disorders. 2. Description of the Related Art Hematopoietic growth factor (HGF) represents a family of biological molecules such as glycoproteins with important regulatory functions in the processes of proliferation, differentiation, and functional activation of hematopoietic progenitors and mature blood cells. HGF compounds can be potent regulators of blood cell proliferation and development in the bone marrow. They are able to augment hematopoiesis when bone marrow dysfunction exists. Recombinant DNA technology has made it possible to clone the genes responsible for many of these factors. One example of an HGF is Thrombopoietin (TPO), also referred to as c-Mpl ligand, mpl ligand, megapoietin, and megakaryocyte growth and development factor, is a glycoprotein that has been shown to be involved in production of platelets. See e.g., Wendling, F., et. al., Biotherapy 10(4):269-77 (1998); Kuter D. J. et al., The Oncologist, 1:98-106 (1996); Metcalf, Nature 369: 519-520 (1994), all of which are incorporated herein by reference in their entirety. TPO has been cloned and its amino acid sequence and the cDNA sequence encoding it have been described. See e.g., U.S. Pat. No. 5,766,581; Kuter, D. J. et al., Proc. Natl. Acad. Sci., 91:11104-11108 (1994); de Sauvage F. V., et al., Nature, 369: 533-538 (1994); Lok, S. et al., Nature 369:565-568 (1994); Wending, F. et al., Nature, 369: 571-574 (1994), all of which are incorporated herein by reference in their entirety. In certain instances, TPO activity results from binding of TPO to the TPO receptor (also called MPL). The TPO receptor has been cloned and its amino acid sequence has been described. See e.g., Vigon et al., Proc. Natl. Acad. Sci., 89:5640-5644 (1992), which is incorporated herein by reference in its entirety. In certain instances, TPO modulators may be useful in treating a variety of hematopoietic conditions, including, but not limited to, thrombocytopenia. See e.g., Baser et al. Blood 89:3118-3128 (1997); Fanucchi et al. New Engl. J. Med. 336:404-409 (1997), both of which are incorporated herein by reference in their entirety. For example, patients undergoing certain chemotherapies, including but not limited to chemotherapy and/or radiation therapy for the treatment of cancer, may have reduced platelet levels. In certain instances, treating such patients with a selective TPO modulator increases platelet levels. In certain instances, selective TPO modulators stimulate production of glial cells, which may result in repair of damaged nerve cells. Another example of an HGF is the glycoprotein hormone erythropoietin (EPO). EPO is an essential viability and growth factor for the erythrocytic progenitors. EPO is a member of the family of class I cytokines which fold into a compact globular structure consisting of 4 α-helical bundles. Its molecular mass is 30.4 kDa, although it migrates with an apparent size of 34-38 kDa on SDS-polyacrylamide gels. The peptide core of 165 amino acids suffices for receptor-binding and in vitro stimulation of erythropoiesis, while the carbohydrate portion (40% of the total molecule) is required for the in vivo survival of the hormone. The 4 carbohydrate chains of EPO have been analyzed in detail. The 3 complex-type N-linked oligosaccharides at asparagines 24, 38 and 83 appear involved in stabilizing EPO in circulation. EPO is mainly produced by hepatocytes during the fetal stage. After birth, almost all circulating EPO originates from peritubular fibroblast-like cells located in the cortex of the kidneys. Transcription factors of the GATA-family may be important in the control of the time-specific and tissue-specific expression of the EPO gene. In adults, minor amounts of EPO mRNA are expressed in liver parenchyma, spleen, lung, testis and brain. In brain, EPO exerts neurotrophic and neuroprotective effects, which are separate from the action of circulating EPO on erythropoietic tissues. See e.g., Jelkmann, W., Internal Medicine Vol. 43, No. 8 (August 2004). SUMMARY OF THE INVENTION In certain embodiments, the present embodiments provide a compound of Formula I: wherein: R 1 is selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 2 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D , SR C , NO 2 , CN, (CH 2 ) m R E , an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 3 is selected from the group consisting of hydrogen, halogen, OR A , NR A R B , and SR A ; or R 1 and R 3 are linked to form an optionally substituted heterocycle; R 4 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 8 alkyl, an optionally substituted C 1 -C 8 haloalkyl, an optionally substituted C 1 -C 8 heteroalkyl, and (CH 2 ) m R E ; R 5 is selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R A is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R B is selected from the group consisting of hydrogen, SO 2 R F , COR F , CONR C R D , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R C and R D are each independently selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; or one of R C and R D is an optionally substituted C 2 -C 6 alkyl and the other of R C and R D is null; or R C and R D are linked to form an optionally substituted C 3 -C 8 ring; R E is selected from the group consisting of an optionally substituted aryl and an optionally substituted heteroaryl; R F is selected from the group consisting of hydrogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, and an optionally substituted aryl or heteroaryl; A is selected from the group consisting of an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; E is a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms, and optionally fused with a nonaromatic heterocycle or carbocycle; L is selected from the group consisting of null, C(R A ) 2 , CO, CONR A , NR A CO, NR A CS, NR A C(S)NR B and an optionally substituted C 1 -C 6 heteroalkyl; X is N or CR 5 ; Y is selected from the group consisting of a 1-4 atom spacer comprising one or more groups selected from an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 heteroalkyl, an optionally substituted phenyl, and an optionally substituted heteroaryl; Z is selected from the group consisting of null, a 2-5 atom spacer selected from an optionally substituted C 6 -C 10 aryl and an optionally substituted C 1 -C 8 heteroaryl, and a 1-5 atom spacer of selected from an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 heteroalkyl, and an optionally substituted C 1 -C 6 haloalkyl; and m is 0, 1, or 2. Certain embodiments relate to compounds with the following structures: wherein: R 1 selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 2 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D , SR C , NO 2 , CN, (CH 2 ) m R E , an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; or R 2 and R 1 are linked to form an optionally substituted C 5 -C 8 ring; R 3 is selected from the group consisting of hydrogen, halogen, OR A , NR A R B , and SR A ; or R 1 and R 2 are linked to form an optionally substituted heterocycle; R 4 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 8 alkyl, an optionally substituted C 1 -C 8 haloalkyl, an optionally substituted C 1 -C 8 heteroalkyl, and (CH 2 ) m R E ; R 5 selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 6 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D , NO 2 , CN, CO 2 R A , CONR C R D , (CH 2 ) m R E , an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 7 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and an optionally substituted aryl or heteroaryl; R A is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R B is selected from hydrogen, SO 2 R F , COR F , CONR C R D , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R C and R D are each independently selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; or one of R C and R D is an optionally substituted C 2 -C 6 alkyl and the other of R C and R D is null; or R C and R D are linked to form an optionally substituted C 3 -C 8 ring; R E is selected from an optionally substituted aryl and an optionally substituted heteroaryl; R F is selected from the group consisting of hydrogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, and an optionally substituted aryl or heteroaryl; A is selected from the group consisting of an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; E is a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms, and optionally fused with a nonaromatic heterocycle or carbocycle; X is N or CR 5 ; Z is selected from the group consisting of null, a 2-5 atom spacer selected from an optionally substituted C 6 -C 10 aryl and an optionally substituted C 1 -C 8 heteroaryl, and a 1-5 atom spacer of selected from an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 heteroalkyl, and an optionally substituted C 1 -C 6 haloalkyl; and m is 0, 1, or 2; with the proviso that none of R 2 , R 3 , and R 4 of the formula II is —(CH 2 ) 0-6 —OH when it is at the ortho position; with the proviso that none of R 2 , R 3 , R 4 , and substituents of A or Z contain a carboxylic acid or carboxylic acid derivative or a carboxylic acid bioisostere. In certain embodiments, the compounds with the following structures are provided: wherein: R 30 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D ; SR C , NO 2 , CN, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 31 selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 32 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D ; SR C , NO 2 , CN, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 10 heteroalkyl; R 33 is selected from the group consisting of hydrogen, halogen, OR A , NR A R B , and SR A ; or R 31 and R 33 are linked to form an optionally substituted heterocycle; R 34 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 8 alkyl, an optionally substituted C 1 -C 8 haloalkyl, an optionally substituted C 1 -C 8 heteroalkyl, (CH 2 ) m R E , and CH 2 O(CH 2 ) m R E ; R A is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R B is selected from the group consisting of hydrogen, SO 2 R F , COR F , CONR C R D , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R C and R D are each independently selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; or one of R C and R D is an optionally substituted C 2 -C 6 alkyl and the other of R C and R D is null; or R C and R D are linked to form an optionally substituted C 3 -C 8 ring; R E is selected from an optionally substituted aryl and an optionally substituted heteroaryl; R F is selected from the group consisting of hydrogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, and an optionally substituted aryl or heteroaryl; A 3 is selected from the group consisting of an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, a nonaromatic heterocycle, OR C , NR A R B , and (CH 2 ) m R E ; E 3 is a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms, and optionally fused with a nonaromatic heterocycle or carbocycle; L 3 is selected from the group consisting of CR C R D , O, S, NR A , N═CR C , an optionally substituted C 1 -C 4 alkyl, an optionally substituted C 1 -C 4 haloalkyl, and an optionally substituted C 1 -C 4 heteroalkyl; or L 3 and R 31 are linked to form an optionally substituted C 3 -C 8 ring; Z 3 is selected from the group consisting of a C 6 -C 10 arylalkyl, a C 6 -C 10 arylheteroalkyl, a C 3 -C 10 arylalkylhetero, a C 3 -C 10 heteroarylheteroalkyl, and a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms and optionally fused with a nonaromatic heterocycle or carbocycle; and m is 0, 1, or 2. In certain embodiments, a compound of Formula I, II, III, or IV, is a hematopoietic growth factor mimetic. In certain embodiments, provided are methods for modulating activity of HGF receptors. Such methods comprise contacting a cell with one or more compounds of the present embodiments. Such methods include, but are not limited to, contacting HGF and/or HGF receptors with one or more compounds of the present embodiments. In certain embodiments, the embodiments provide a method for identifying a compound that is capable of modulating HGF activity comprising: a) contacting a cell capable of a HGF activity with a compound of the present embodiments; and b) monitoring an effect on the cell. In certain such embodiments, the cell expresses a HGF receptor. In certain embodiments, provided are methods of treating a patient comprising administering to the patient a compound of the present embodiments. In certain embodiments, such a patient suffers from thrombocytopenia. In certain embodiments, one or more compounds of the present embodiments are administered to a patient before, during or after chemotherapy, bone marrow transplantation, and/or radiation therapy. In certain embodiments, one or more compounds of the embodiments are administered to a patient suffering from a plastic anemia, bone marrow failure, and/or idiopathic thrombocytopenia. In certain embodiments, one or more compounds of the present embodiments are administered to a patient suffering from a disease of the nervous system. In certain embodiments, one or more compounds of the present embodiments are administered to a patient suffering from amyotrophic lateral sclerosis, multiple sclerosis, or multiple dystrophy. In certain embodiments, one or more compounds of the present embodiments are administered to a patient with a nerve injury, including, but not limited to, a spinal cord injury. In certain embodiments, provided are pharmaceutical compositions comprising: i) a physiologically acceptable carrier, diluent, or excipient, or a combination thereof; and ii) one or more compounds of the present embodiments. Certain embodiments provide a selective HGF modulator. Certain embodiments provide a selective HGF receptor agonist. Certain embodiments provide a selective HGF receptor antagonist. Certain embodiments provide a selective HGF partial agonist. Certain embodiments provide a selective HGF receptor binding compound. Certain embodiments provide a HGF mimic. DETAILED DESCRIPTION OF THE INVENTION It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the embodiments claimed. In this application, the use of the singular includes the plural unless specifically stated otherwise. In this application, the use of “or” means “and/or” unless stated otherwise. Furthermore, use of the term “including” as well as other forms, such as “includes,” and “included,” is not limiting. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in the application including, but not limited to, patents, patent applications, articles, books, manuals, and treatises are hereby expressly incorporated by reference in their entirety for any purpose. DEFINITIONS Unless specific definitions are provided, the nomenclatures utilized in connection with, and the laboratory procedures and techniques of, analytical chemistry, synthetic organic chemistry, and medicinal and pharmaceutical chemistry described herein are those known in the art. Standard chemical symbols are used interchangeably with the full names represented by such symbols. Thus, for example, the terms “hydrogen” and “H” are understood to have identical meaning. Standard techniques may be used for chemical syntheses, chemical analyses, pharmaceutical preparation, formulation, and delivery, and treatment of patients. Standard techniques may be used for recombinant DNA, oligonucleotide synthesis, and tissue culture and transformation (e.g., electroporation, lipofection). Reactions and purification techniques may be performed e.g., using kits according to manufacturer's specifications or as commonly accomplished in the art or as described herein. The foregoing techniques and procedures may be generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification. See e.g., Sambrook et al. Molecular Cloning: A Laboratory Manual (2d ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989)), which is incorporated herein by reference in its entirety for any purpose. As used herein, the following terms are defined with the following meanings, unless expressly stated otherwise. The term “selective binding compound” refers to a compound that selectively binds to any portion of one or more target. The term “selective HGF receptor binding compound” refers to a compound that selectively binds to any portion of a HGF receptor. The term “selectively binds” refers to the ability of a selective binding compound to bind to a target receptor with greater affinity than it binds to a non-target receptor. In certain embodiments, selective binding refers to binding to a target with an affinity that is at least 10, 50, 100, 250, 500, or 1000 times greater than the affinity for a non-target. The term “target receptor” refers to a receptor or a portion of a receptor capable of being bound by a selective binding compound. In certain embodiments, a target receptor is a HGF receptor. The term “modulator” refers to a compound that alters an activity. For example, a modulator may cause an increase or decrease in the magnitude of a certain activity compared to the magnitude of the activity in the absence of the modulator. In certain embodiments, a modulator is an inhibitor, which decreases the magnitude of one or more activities. In certain embodiments, an inhibitor completely prevents one or more biological activities. In certain embodiments, a modulator is an activator, which increases the magnitude of at least one activity. In certain embodiments the presence of a modulator results in a activity that does not occur in the absence of the modulator. The term “selective modulator” refers to a compound that selectively modulates a target activity. The term “selective HGF modulator” refers to a compound that selectively modulates at least one HGF activity. The term selective HGF modulator includes, but is not limited to “HGF mimic” which refers to a compound, the presence of which results in at least one HGF activity. HGF mimics are described in WO 03/103686A1 and WO 01/21180, both of which are incorporated herein by reference in their entirety. The term “selectively modulates” refers to the ability of a selective modulator to modulate a target activity to a greater extent than it modulates a non-target activity. The term “target activity” refers to a biological activity capable of being modulated by a selective modulator. Certain exemplary target activities include, but are not limited to, binding affinity, signal transduction, enzymatic activity, the proliferation and/or differentiation of progenitor cells, generation of platelets, and alleviation of symptoms of a disease or condition. The term “HGF activity” refers to a biological activity that results, either directly or indirectly from the presence of HGF. Exemplary HGF activities include, but are not limited to, proliferation and or differentiation of progenitor cells to produce platelets; hematopoiesis; growth and/or development of glial cells; repair of nerve cells; and alleviation of thrombocytopenia. The term “thrombocytopenia” refers to a condition wherein the concentration of platelets in the blood of a patient is below what is considered normal for a healthy patient. In certain embodiments, thrombocytopenia is a platelet count less than 450,000, 400,000, 350,000, 300,000, 250,000, 200,000, 150,000, 140,000, 130,000, 120,000, 110,000, 100,000, 75,000, or 50,000 platelets per microliter of blood. The term “receptor mediated activity” refers to any biological activity that results, either directly or indirectly, from binding of a ligand to a receptor. The term “agonist” refers to a compound, the presence of which results in a biological activity of a receptor that is the same as the biological activity resulting from the presence of a naturally occurring ligand for the receptor. The term “partial agonist” refers to a compound, the presence of which results in a biological activity of a receptor that is of the same type as that resulting from the presence of a naturally occurring ligand for the receptor, but of a lower magnitude. The term “antagonist” refers to a compound, the presence of which results in a decrease in the magnitude of a biological activity of a receptor. In certain embodiments, the presence of an antagonist results in complete inhibition of a biological activity of a receptor. The term “alkyl” refers to a branched or unbranched aliphatic hydrocarbon group. An alkyl may be a “saturated alkyl,” which means that it does not contain any alkene or alkyne groups. An alkyl group may be an “unsaturated alkyl,” which means that it comprises at least one alkene or alkyne group. An alkyl, whether saturated or unsaturated, may be branched or straight chain. Alkyls may be cyclic or non-cyclic. Cyclic alkyls may include multicyclic systems including fused alkyl rings. Alkyls may be substituted or unsubstituted. Alkyls include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, ethenyl, propenyl, butenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like, each of which may be optionally substituted. In certain embodiments, an alkyl comprises 1 to 20 carbon atoms (whenever it appears herein, a numerical range such as “1 to 20” refers to each integer in the given range; e.g., “1 to 20 carbon atoms” means that an alkyl group may comprise only 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms, although the term “alkyl” also includes instances where no numerical range of carbon atoms is designated). The term “lower alkyl” refers to an alkyl comprising 1 to 5 carbon atoms. The term “medium alkyl” refers to an alkyl comprising 5 to 10 carbon atoms. An alkyl may be designated as “C 1 -C 4 alkyl” or similar designations. By way of example only, “C 1 -C 4 alkyl” indicates an alkyl having one, two, three, or four carbon atoms, e.g., the alkyl is selected from methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, ethenyl, propenyl, butenyl, ethynyl, propynyl, and butynyl. The term “alkenyl” refers to an alkyl group comprising at least one carbon-carbon double bond. The term “alkynyl” refers to an alkyl group comprising at least one carbon-carbon triple bond. The term “haloalkyl” refers to an alkyl in which at least one hydrogen atom is replaced with a halogen atom. In certain of the embodiments in which two or more hydrogen atom are replaced with halogen atoms, the halogen atoms are all the same as one another. In certain of such embodiments, the halogen atoms are not all the same as one another. The term “heteroalkyl” refers to a branched or unbranched aliphatic hydrocarbon group comprising one or more oxygen, sulfur, nitrogen, or NH. Examples of heteroalkyls include, but are not limited to, CH 3 C(═O)CH 2 —, CH 3 C(═O)CH 2 CH 2 —, CH 3 CH 2 C(═O)CH 2 CH 2 —, CH 3 C(═O)CH 2 CH 2 CH 2 —, CH 3 NHC(═O)CH 2 —, CH 3 C(═O)NHCH 2 —, CH 3 OCH 2 CH 2 —, CH 3 NHCH 2 —, and the like. The term “straight-chain alkoxy” refers to a group comprising the formula: —(CH 2 ) p O— wherein p is any integer. Straight-chain alkoxy does not include substituted or branched alkoxy groups. The term “non-straight-chain-alkoxy-heteroalkyl” refers to any heteroalkyl that is not a straight-chain alkoxy heteroalkyl. Thus, for example, non-straight-chain-alkoxy heteroalkyls include, but are not limited to: 2,2-isopropyloxy; 1,2-propyloxy; 1,1-ethyloxy; methylamino; ethylamino; propylamino; methylpyrrolidino; and methylpiperidino. The term “olefin” refers to a C═C bond. The term “heterohaloalkyl” refers to a heteroalkyl in which at least one hydrogen atom is replaced with a halogen atom. The term “carbocycle” refers to a group comprising a covalently closed ring, wherein each of the atoms forming the ring is a carbon atom. Carbocylic rings may be formed by three, four, five, six, seven, eight, nine, or more than nine carbon atoms. Carbocycles may be optionally substituted. The term “heterocycle” refers to a group comprising a covalently closed ring wherein at least one atom forming the ring is a heteroatom. Heterocyclic rings may be formed by three, four, five, six, seven, eight, nine, or more than nine atoms. Any number of those atoms may be heteroatoms (i.e., a heterocyclic ring may comprise one, two, three, four, five, six, seven, eight, nine, or more than nine heteroatoms). In heterocyclic rings comprising two or more heteroatoms, those two or more heteroatoms may be the same or different from one another. Heterocycles may be optionally substituted. Binding to a heterocycle can be at a heteroatom or via a carbon atom. For example, binding for benzo-fused derivatives, may be via a carbon of the benzenoid ring. Examples of heterocycles include, but are not limited to the following: wherein D, E, F, and G independently represent a heteroatom. Each of D, E, F, and G may be the same or different from one another. The term “heteroatom” refers to an atom other than carbon or hydrogen. Heteroatoms are typically independently selected from oxygen, sulfur, nitrogen, and phosphorus, but are not limited to those atoms. In embodiments in which two or more heteroatoms are present, the two or more heteroatoms may all be the same as one another, or some or all of the two or more heteroatoms may each be different from the others. The term “aromatic” refers to a group comprising a covalently closed ring having a delocalized π-electron system. Aromatic rings may be formed by five, six, seven, eight, nine, or more than nine atoms. Aromatics may be optionally substituted. Examples of aromatic groups include, but are not limited to phenyl, naphthalenyl, phenanthrenyl, anthracenyl, tetralinyl, fluorenyl, indenyl, and indanyl. The term aromatic includes, for example, benzenoid groups, connected via one of the ring-forming carbon atoms, and optionally carrying one or more substituents selected from an aryl, a heteroaryl, a cycloalkyl, a non-aromatic heterocycle, a halo, a hydroxy, an amino, a cyano, a nitro, an alkylamido, an acyl, a C 1-6 alkoxy, a C 1-6 alkyl, a C 1-6 hydroxyalkyl, a C 1-6 aminoalkyl, a C 1-6 alkylamino, an alkylsulfenyl, an alkylsulfinyl, an alkylsulfonyl, an sulfamoyl, or a trifluoromethyl. In certain embodiments, an aromatic group is substituted at one or more of the para, meta, and/or ortho positions. Examples of aromatic groups comprising substitutions include, but are not limited to, phenyl, 3-halophenyl, 4-halophenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 3-aminophenyl, 4-aminophenyl, 3-methylphenyl, 4-methylphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 4-trifluoromethoxyphenyl, 3-cyanophenyl, 4-cyanophenyl, dimethylphenyl, naphthyl, hydroxynaphthyl, hydroxymethylphenyl, (trifluoromethyl)phenyl, alkoxyphenyl, 4-morpholin-4-ylphenyl, 4-pyrrolidin-1-ylphenyl, 4-pyrazolylphenyl, 4-triazolylphenyl, and 4-(2-oxopyrrolidin-1-yl)phenyl. The term “aryl” refers to an aromatic group wherein each of the atoms forming the ring is a carbon atom. Aryl rings may be formed by five, six, seven, eight, nine, or more than nine carbon atoms. Aryl groups may be optionally substituted. The term “heteroaryl” refers to an aromatic group wherein at least one atom forming the aromatic ring is a heteroatom. Heteroaryl rings may be formed by three, four, five, six, seven, eight, nine, or more than nine atoms. Heteroaryl groups may be optionally substituted. Examples of heteroaryl groups include, but are not limited to, aromatic C 3-8 heterocyclic groups comprising one oxygen or sulfur atom or up to four nitrogen atoms, or a combination of one oxygen or sulfur atom and up to two nitrogen atoms, and their substituted as well as benzo- and pyrido-fused derivatives, for example, connected via one of the ring-forming carbon atoms. In certain embodiments, heteroaryl groups are optionally substituted with one or more substituents, independently selected from halo, hydroxy, amino, cyano, nitro, alkylamido, acyl, C 1-6 -alkoxy, C 1-6 -alkyl, C 1-6 -hydroxyalkyl, C 1-6 -aminoalkyl, C 1-6 -alkylamino, alkylsulfenyl, alkylsulfinyl, alkylsulfonyl, sulfamoyl, or trifluoromethyl. Examples of heteroaryl groups include, but are not limited to, unsubstituted and mono- or di-substituted derivatives of furan, benzofuran, thiophene, benzothiophene, pyrrole, pyridine, indole, oxazole, benzoxazole, isoxazole, benzisoxazole, thiazole, benzothiazole, isothiazole, imidazole, benzimidazole, pyrazole, indazole, tetrazole, quinoline, isoquinoline, pyridazine, pyrimidine, purine and pyrazine, furazan, 1,2,3-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, triazole, benzotriazole, pteridine, phenoxazole, oxadiazole, benzopyrazole, quinolizine, cinnoline, phthalazine, quinazoline, and quinoxaline. In some embodiments, the substituents are halo, hydroxy, cyano, O—C 1-6 -alkyl, C 1-6 -alkyl, hydroxy-C 1-6 -alkyl, and amino-C 1-6 -alkyl. The term “non-aromatic ring” refers to a group comprising a covalently closed ring that does not have a delocalized π-electron system. The term “cycloalkyl” refers to a group comprising a non-aromatic ring wherein each of the atoms forming the ring is a carbon atom. Cycloalkyl rings may be formed by three, four, five, six, seven, eight, nine, or more than nine carbon atoms. Cycloalkyls may include multicyclic systems (e.g., fused ring systems). Cycloalkyls may be optionally substituted. In certain embodiments, a cycloalkyl comprises one or more unsaturated bonds. Examples of cycloalkyls include, but are not limited to, cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, cycloheptane, and cycloheptene. The term “non-aromatic heterocycle” refers to a group comprising a non-aromatic ring wherein one or more atoms forming the ring is a heteroatom and optionally includes one or more carbonyl or thiocarbonyl groups as part of the ring. Non-aromatic heterocyclic rings may be formed by three, four, five, six, seven, eight, nine, or more than nine atoms. Non-aromatic heterocycles may be optionally substituted. Examples of non-aromatic heterocycles include, but are not limited to, lactams, lactones, cyclic imides, cyclic thioimides, cyclic carbamates, tetrahydrothiopyran, 4H-pyran, tetrahydropyran, piperidine, 1,3-dioxin, 1,3-dioxane, 1,4-dioxin, 1,4-dioxane, piperazine, 1,3-oxathiane, 1,4-oxathiin, 1,4-oxathiane, tetrahydro-1,4-thiazine, 2H-1,2-oxazine, maleimide, succinimide, barbituric acid, thiobarbituric acid, dioxopiperazine, hydantoin, dihydrouracil, morpholine, trioxane, hexahydro-1,3,5-triazine, tetrahydrothiophene, tetrahydrofuran, pyrroline, pyrrolidine, pyrrolidone, pyrrolidione, pyrazoline, pyrazolidine, imidazoline, imidazolidine, 1,3-dioxole, 1,3-dioxolane, 1,3-dithiole, 1,3-dithiolane, isoxazoline, isoxazolidine, oxazoline, oxazolidine, oxazolidinone, thiazoline, thiazolidine, and 1,3-oxathiolane. The term “arylalkyl” refers to a group comprising an aryl group bound to an alkyl group. The term “carbocycloalkyl” refers to a group comprising a carbocyclic cycloalkyl ring. Carbocycloalkyl rings may be formed by three, four, five, six, seven, eight, nine, or more than nine carbon atoms. Carbocycloalkyl groups may be optionally substituted. The term “ring” refers to any covalently closed structure. Rings include, for example, carbocycles (e.g., aryls and cycloalkyls), heterocycles (e.g., heteroaryls and non-aromatic heterocycles), aromatics (e.g., aryls and heteroaryls), and non-aromatics (e.g., cycloalkyls and non-aromatic heterocycles). Rings may be optionally substituted. Rings may form part of a ring system. The term “ring system” refers to a either a single ring or two or more rings, wherein, if two or more rings are present, the two or more of the rings are fused. The term “fused” refers to structures in which two or more rings share one or more bonds. The term “carboxylic acid bioisostere” refers to a group that is biologically equivalent to a carboxylic acid. For example, carboxylic acid bioisosteres include, but are not limited to, tetrazole, NHSO 2 R 15 , OC(S)NR 10 R 11 , SC(O)NR 10 R 11 , thiazolidinedione, oxazolidinedione, and 1-oxa-2,4-diazolidine-3,5-dione. In certain embodiments, a carboxylic acid bioisostere comprises the following structure: wherein A, 13, and C are each independently selected from O, S, and N. The term “spacer” refers to an atom or group of atoms that separate two or more groups from one another by a desired number of atoms. For example, in certain embodiments, it may be desirable to separate two or more groups by one, two, three, four, five, six, or more than six atoms. In such embodiments, any atom or group of atoms may be used to separate those groups by the desired number of atoms. Spacers are optionally substituted. In certain embodiments, a spacer comprises saturated or unsaturated alkyls, heteroalkyls and/or haloalkyls. In certain embodiments, a spacer comprises atoms that are part of a ring. Solely for the purposes of illustration, and without limiting the above definition, some examples of spacers are provided. Examples of 1 atom spacers include, but are not limited to, the following: where A and B represent groups which are separated by the desired number of atoms. Examples of 2 atom spacers include, but are not limited to, the following: where A and B represent groups which are separated by the desired number of atoms. Examples of 3 atom spacers include, but are not limited to, the following: where A and B represent groups which are separated by the desired number of atoms. As is evident from the above examples, the atoms that create the desired separation may themselves be part of a group. That group may be, for example, an alkyl, heteroalkyl, haloalkyl, heterohaloalkyl, cycloalkyl, aryl, arylalkyl, heteroaryl, non-aromatic heterocycle, or substituted alkyl all of which are optionally substituted. Thus the term “1-5 atom spacer” refers to a spacer that separates two groups by 1, 2, 3, 4, or 5 atoms and does not indicate the total size of the group that constitutes the spacer. As used herein, the term “linked to form a ring” refers to instances where two atoms that are bound either to a single atom or to atoms that are themselves ultimately bound, are each bound to a linking group, such that the resulting structure forms a ring. That resulting ring comprises the two atoms that are linked to form a ring, the atom (or atoms) that previously linked those atoms, and the linker. For example, if A and B below are “linked to form a ring” the resulting ring includes A, B, C, and a linking group. Unless otherwise indicated, that linking group may be of any length and may be optionally substituted. Referring to the above example, resulting structures include, but are not limited to: and the like. In certain embodiments, the two substituents that together form a ring are not immediately bound to the same atom. For example, if A and B, below, are linked to form a ring: the resulting ring comprises A, B, the two atoms that already link A and B and a linking group. Examples of resulting structures include, but are not limited to: and the like. In certain embodiments, the atoms that together form a ring are separated by three or more atoms. For example, if A and B, below, are linked to form a ring: the resulting ring comprises A, B, the 3 atoms that already link A and B, and a linking group. Examples of resulting structures include, but are not limited to: and the like. As used herein, the term “together form a bond” refers to the instance in which two substituents to neighboring atoms are null the bond between the neighboring atoms becomes a double bond. For example, if A and B below “together form a bond” the resulting structure is: The term “null” refers to a group being absent from a structure. For example, in the structure where in certain instances X is N, if X is N, one of R′ or R″ is null, meaning that only three groups are bound to the N. The substituent “R” appearing by itself and without a number designation refers to a substituent selected from alkyl, cycloalkyl, aryl, heteroaryl (bonded through a ring carbon) and non-aromatic heterocycle (bonded through a ring carbon). The term “O-carboxy” refers to the group consisting of formula RC(═O)O—. The term “C-carboxy” refers to the group consisting of formula —C(═O)OR. The term “acetyl” refers to the group consisting of formula —C(═O)CH 3 . The term “trihalomethanesulfonyl” refers to the group consisting of formula X 3 CS(═O) 2 — where X is a halogen. The term “cyano” refers to the group consisting of formula —CN. The term “isocyanato” refers to the group consisting of formula —NCO. The term “thiocyanato” refers to the group consisting of formula —CNS. The term “isothiocyanato” refers to the group consisting of formula —NCS. The term “sulfonyl” refers to the group consisting of formula —S(═O)—R. The term “S-sulfonamido” refers to the group consisting of formula —S(═O) 2 NR. The term “N-sulfonamido” refers to the group consisting of formula RS(═O) 2 NH—. The term “trihalomethanesulfonamido” refers to the group consisting of formula X 3 CS(═O) 2 NR—. The term “O-carbamyl” refers to the group consisting of formula —OC(═O)—NR. The term “N-carbamyl” refers to the group consisting of formula ROC(═O)NH—. The term “O-thiocarbamyl” refers to the group consisting of formula —OC(═S)—NR. The term “N-thiocarbamyl” refers to the group consisting of formula ROC(═S)NH—. The term “C-amido” refers to the group consisting of formula —C(═O)—NR 2 . The term “N-amido” refers to the group consisting of formula RC(═O)NH—. The term “oxo” refers to the group consisting of formula ═O. The term “carbonyl” refers to the group consisting of formula —C(═O)R. The term “thiocarbonyl” refers to the group consisting of formula —C(═S)R. The term “dihydropyrazolylene” refers to a di-radical of an optionally substituted dihydropyrazole ring, wherein the dihydropyrazole ring has the structure: and wherein the two radicals may be at any positions on the ring. The term “pyrazolyl” refers to a radical of a pyrzole ring, wherein the pyrzole ring has the structure: and wherein the radical may be at any position on the ring. The term “ester” refers to a chemical moiety with formula —(R) n —COOR′, where R and R′ are independently selected from alkyl, cycloalkyl, aryl, heteroaryl (bonded through a ring carbon) and non-aromatic heterocycle (bonded through a ring carbon), where n is 0 or 1. The term “amide” refers to a chemical moiety with formula —(R) n —C(O)NHR′ or —(R) n —NHC(O)R′, where R and R′ are independently selected from alkyl, cycloalkyl, aryl, heteroaryl (bonded through a ring carbon) and heteroalicyclic (bonded through a ring carbon), where n is 0 or 1. In certain embodiments, an amide may be an amino acid or a peptide. The terms “amine,” “hydroxy,” and “carboxyl” include such groups that have been esterified or amidified. Procedures and specific groups used to achieve esterification and amidification are known to those of skill in the art and can readily be found in reference sources such as Greene and Wuts, Protective Groups in Organic Synthesis, 3 rd Ed., John Wiley & Sons, New York, N.Y., 1999, which is incorporated herein in its entirety. Unless otherwise indicated, the term “optionally substituted,” refers to a group in which none, one, or more than one of the hydrogen atoms has been replaced with one or more group(s) individually and independently selected from: alkyl, heteroalkyl, haloalkyl, heterohaloalkyl, cycloalkyl, aryl, arylalkyl, heteroaryl, non-aromatic heterocycle, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, thiocarbonyl, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, S-sulfonamido, N-sulfonamido, C-carboxy, O-carboxy, isocyanato, thiocyanato, isothiocyanato, nitro, silyl, trihalomethanesulfonyl, oxo, and amino, including mono- and di-substituted amino groups, and the protected derivatives of amino groups. Such protective derivatives (and protecting groups that may form such protective derivatives) are known to those of skill in the art and may be found in references such as Greene and Wuts, above. In embodiments in which two or more hydrogen atoms have been substituted, the substituent groups may together form a ring. Throughout the specification, groups and substituents thereof can be chosen by one skilled in the field to provide stable moieties and compounds. The term “carrier” refers to a compound that facilitates the incorporation of another compound into cells or tissues. For example, dimethyl sulfoxide (DMSO) is a commonly used carrier for improving incorporation of certain organic compounds into cells or tissues. The term “pharmaceutical agent” refers to a chemical compound or composition capable of inducing a desired therapeutic effect in a patient. In certain embodiments, a pharmaceutical agent comprises an active agent, which is the agent that induces the desired therapeutic effect. In certain embodiments, a pharmaceutical agent comprises a prodrug. In certain embodiments, a pharmaceutical agent comprises inactive ingredients such as carriers, excipients, and the like. The term “therapeutically effective amount” refers to an amount of a pharmaceutical agent sufficient to achieve a desired therapeutic effect. The term “prodrug” refers to an pharmaceutical agent that is converted from a less active form into a corresponding more active form in vivo. The term “pharmaceutically acceptable” refers to a formulation of a compound that does not significantly abrogate the biological activity, a pharmacological activity and/or other properties of the compound when the formulated compound is administered to a patient. In certain embodiments, a pharmaceutically acceptable formulation does not cause significant irritation to a patient. The term “co-administer” refers to administering more than one pharmaceutical agent to a patient. In certain embodiments, co-administered pharmaceutical agents are administered together in a single dosage unit. In certain embodiments, co-administered pharmaceutical agents are administered separately. In certain embodiments, co-administered pharmaceutical agents are administered at the same time. In certain embodiments, co-administered pharmaceutical agents are administered at different times. The term “patient” includes human and animal subjects. The term “substantially pure” means an object species (e.g., compound) is the predominant species present (i.e., on a molar basis it is more abundant than any other individual species in the composition). In certain embodiments, a substantially purified fraction is a composition wherein the object species comprises at least about 50 percent (on a molar basis) of all species present. In certain embodiments, a substantially pure composition will comprise more than about 80%, 85%, 90%, 95%, or 99% of all species present in the composition. In certain embodiments, the object species is purified to essential homogeneity (contaminant species cannot be detected in the composition by conventional detection methods) wherein the composition consists essentially of a single species. The term “tissue-selective” refers to the ability of a compound to modulate a biological activity in one tissue to a greater or lesser degree than it modulates a biological activity in another tissue. The biological activities in the different tissues may be the same or they may be different. The biological activities in the different tissues may be mediated by the same type of target receptor. For example, in certain embodiments, a tissue-selective compound may modulate receptor mediated biological activity in one tissue and fail to modulate, or modulate to a lesser degree, receptor mediated biological activity in another tissue type. The term “monitoring” refers to observing an effect or absence of any effect. In certain embodiments, one monitors cells after contacting those cells with a compound of the present embodiments. Examples of effects that may be monitored include, but are not limited to, changes in cell phenotype, cell proliferation, receptor activity, or the interaction between a receptor and a compound known to bind to the receptor. The term “cell phenotype” refers to physical or biological characteristics. Examples of characteristics that constitute phenotype included, but are not limited to, cell size, cell proliferation, cell differentiation, cell survival, apoptosis (cell death), or the utilization of a metabolic nutrient (e.g., glucose uptake). Certain changes or the absence of changes in cell phenotype are readily monitored using techniques known in the art. The term “cell proliferation” refers to the rate at which cells divide. In certain embodiments, cells are in situ in an organism. In certain embodiments, cells are grown in vitro in a vessel. The number of cells growing in a vessel can be quantified by a person skilled in the art (e.g., by counting cells in a defined area using a microscope or by using laboratory apparatus that measure the density of cells in an appropriate medium). One skilled in that art can calculate cell proliferation by determining the number of cells at two or more times. The term “contacting” refers to bringing two or more materials into close enough proximity that they may interact. In certain embodiments, contacting can be accomplished in a vessel such as a test tube, a Petri dish, or the like. In certain embodiments, contacting may be performed in the presence of additional materials. In certain embodiments, contacting may be performed in the presence of cells. In certain of such embodiments, one or more of the materials that are being contacted may be inside a cell. Cells may be alive or may dead. Cells may or may not be intact. Certain Compounds Certain compounds that modulate one or more HGF activity and/or bind to HGF receptors play a role in health. In certain embodiments, compounds are useful for treating any of a variety of diseases or conditions. A surprising discovery has been made that compounds with activity at the TPO receptor or other specific receptors also have broader HGF activity which can modulate HGF receptors affecting a wide range of diseases and disorders. Certain embodiments provide selective HGF modulators. Certain embodiments provide selective HGF receptor binding agents. Certain embodiments provide methods of making and methods of using selective HGF modulators and/or selective HGF receptor binding agents. In certain embodiments, selective HGF modulators are agonists, partial agonists, and/or antagonists for the HGF receptor. The compounds disclosed herein can be used alone or in combination with other agents, for example, to modulate hematopoiesis, erythropoiesis, granulopoiesis, thrombopoiesis, and myelopoiesis. The instant compounds can also be used alone or in combination with other agents in treatment or prevention of a disease or condition caused by abnormal function of hematopoiesis, erythropoiesis, granulopoiesis, thrombopoiesis, and myelopoiesis. Some non-limiting examples of diseases include anemia, neutropenia, thrombocytopenia, cardiovascular disorders, immune/autoimmune disorders, cancers, infectious disorders or diseases, and neurologic disorders. In certain embodiments, the present embodiments provide a compound of Formula I: wherein: R 1 is selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 2 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D , SR C , NO 2 , CN, (CH 2 ) m R E , an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 3 is selected from the group consisting of hydrogen, halogen, OR A , NR A R B , and SR A ; or R 1 and R 3 are linked to form an optionally substituted heterocycle; R 4 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 8 alkyl, an optionally substituted C 1 -C 8 haloalkyl, an optionally substituted C 1 -C 8 heteroalkyl, and (CH 2 ) m R E ; R 5 is selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R A is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R B is selected from the group consisting of hydrogen, SO 2 R F , COR F , CONR C R D , Co alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R C and R D are each independently selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; or one of R C and R D is an optionally substituted C 2 -C 6 alkyl and the other of R C and R D is null; or R C and R D are linked to form an optionally substituted C 3 -C 8 ring; R E is selected from the group consisting of an optionally substituted aryl and an optionally substituted heteroaryl; R F is selected from the group consisting of hydrogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, and an optionally substituted aryl or heteroaryl; A is selected from the group consisting of an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; E is a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms, and optionally fused with a nonaromatic heterocycle or carbocycle; L is selected from the group consisting of null, C(R A ) 2 , CO, CONR A , NR A CO, NR A CS, NR A C(S)NR B and an optionally substituted C 1 -C 6 heteroalkyl; X is N or CR 5 ; Y is selected from the group consisting of a 1-4 atom spacer comprising one or more groups selected from an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 heteroalkyl, an optionally substituted phenyl, and an optionally substituted heteroaryl; Z is selected from the group consisting of null, a 2-5 atom spacer selected from an optionally substituted C 6 -C 10 aryl and an optionally substituted C 1 -C 8 heteroaryl, and a 1-5 atom spacer of selected from an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 heteroalkyl, and an optionally substituted C 1 -C 6 haloalkyl; and m is 0, 1, or 2. Certain embodiments relate to compounds with the following structures: wherein: R 1 selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 2 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D , SR C , NO 2 , CN, (CH 2 ) m R E , an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; or R 2 and R 1 are linked to form an optionally substituted C 5 -C 8 ring; R 3 is selected from the group consisting of hydrogen, halogen, OR A , NR A R B , and SR A ; or R 1 and R 2 are linked to form an optionally substituted heterocycle; R 4 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 8 alkyl, an optionally substituted C 1 -C 8 haloalkyl, an optionally substituted C 1 -C 8 heteroalkyl, and (CH 2 ) m R E ; R 5 selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 6 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D , NO 2 , CN, CO 2 R A , CONR C R D , (CH 2 ) m R E , an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 7 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and an optionally substituted aryl or heteroaryl; R A is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R B is selected from hydrogen, SO 2 R F , COR F , CONR C R D , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R C and R D are each independently selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; or one of R C and R D is an optionally substituted C 2 -C 6 alkyl and the other of R C and R D is null; or R C and R D are linked to form an optionally substituted C 3 -C 8 ring; R E is selected from an optionally substituted aryl and an optionally substituted heteroaryl; R F is selected from the group consisting of hydrogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, and an optionally substituted aryl or heteroaryl; A is selected from the group consisting of an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; E is a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms, and optionally fused with a nonaromatic heterocycle or carbocycle; X is N or CR 5 ; Z is selected from the group consisting of null, a 2-5 atom spacer selected from an optionally substituted C 6 -C 10 aryl and an optionally substituted C 1 -C 8 heteroaryl, and a 1-5 atom spacer of selected from an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 heteroalkyl, and an optionally substituted C 1 -C 6 haloalkyl; and m is 0, 1, or 2; with the proviso that none of R 2 , R 3 , and R 4 of formula II is —(CH 2 ) 0-6 —OH when it is at the ortho position; with the proviso that none of A, Z, R 2 , R 3 , and R 4 contain a carboxylic acid or carboxylic acid derivative or a carboxylic acid bioisostere. In certain embodiments, the compounds with the following structures are provided: wherein: R 30 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D ; SR C , NO 2 , CN, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 31 selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 6 heteroalkyl; R 32 is selected from the group consisting of hydrogen, halogen, OR C , NR C R D ; SR C , NO 2 , CN, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, and an optionally substituted C 1 -C 10 heteroalkyl; R 33 is selected from the group consisting of hydrogen, halogen, OR A , NR A R B , and SR A ; or R 31 and R 33 are linked to form an optionally substituted heterocycle; R 34 is selected from the group consisting of hydrogen, halogen, an optionally substituted C 1 -C 8 alkyl, an optionally substituted C 1 -C 8 haloalkyl, an optionally substituted C 1 -C 8 heteroalkyl, (CH 2 ) m R E , and CH 2 O(CH 2 ) m R E ; R A is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R B is selected from the group consisting of hydrogen, SO 2 R F , COR F , CONR C R D , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 heteroalkyl, and C 1 -C 6 heterohaloalkyl; R C and R D are each independently selected from the group consisting of hydrogen, an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, and (CH 2 ) m R E ; or one of R C and R D is an optionally substituted C 2 -C 6 alkyl and the other of R C and R D is null; or R C and R D are linked to form an optionally substituted C 3 -C 8 ring; R E is selected from an optionally substituted aryl and an optionally substituted heteroaryl; R F is selected from the group consisting of hydrogen, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, and an optionally substituted aryl or heteroaryl; A 3 is selected from the group consisting of an optionally substituted C 1 -C 6 alkyl, an optionally substituted C 1 -C 6 haloalkyl, an optionally substituted C 1 -C 6 heteroalkyl, a nonaromatic heterocycle, OR C , NR A R B , and (CH 2 ) m R E ; E 3 is a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms, and optionally fused with a nonaromatic heterocycle or carbocycle; L 3 is selected from the group consisting of CR C R D , O, S, NR A , N═CR C , an optionally substituted C 1 -C 4 alkyl, an optionally substituted C 1 -C 4 haloalkyl, and an optionally substituted C 1 -C 4 heteroalkyl; or L 3 and R 31 are linked to form an optionally substituted C 3 -C 8 ring; Z 3 is selected from the group consisting of a C 6 -C 10 arylalkyl, a C 6 -C 10 arylheteroalkyl, a C 3 -C 10 heteroarylalkyl, a C 3 -C 10 heteroarylheteroalkyl, and a monocyclic or bicyclic aromatic ring optionally containing one or more heteroatoms and optionally fused with a nonaromatic heterocycle or carbocycle; and m is 0, 1, or 2 Certain compounds of the present embodiments may exist as stereoisomers including optical isomers. The present disclosure is intended to include all stereoisomers and both the racemic mixtures of such stereoisomers as well as the individual enantiomers that may be separated according to methods that are known in the art or that may be excluded by synthesis schemes known in the art designed to yield predominantly one enantiomer relative to another. Certain Synthesis Methods The process of Scheme I is a multi-step synthetic sequence that commences with a metal catalyzed cross-coupling or simple alkylation of a cyclic amide compound such as structure 1 and an aryl or alkyl bromide to provide an N-substituted intermediate of structure 2. This is then converted into the structure 3 via reaction with either dimethylformamide dimethylacetal (or equivalent) or triethylorthoformate. This is then reacted with an amine to give the structure 4. The process of Scheme II is a synthetic sequence that commences with the diazotization of an aromatic primary amine such as structure 5 under standard conditions followed by the treatment of the appropriate coupling partner such as 2 under a basic condition to give the final products of structure 6. Scheme III describes synthesis of the pyrazolone compounds of structure 10. Diazotization of an aromatic primary amine such as structure 5 under standard conditions followed by the treatment of a ketoester compound of structure 7 under a basic condition gives the intermediates of structure 8. Condensation of compounds of structure 8 and hydrazine derivative 9 affords the final compounds of structure 10. Scheme IV describes the synthesis of compounds of structure 14 from a carboxylic acid derivative of structure 11 via a hydrazide intermediate (12) condensation reaction with an aldehyde or a ketone derivative (13). One of skill in the art will recognize that analogous synthesis schemes may be used to synthesize similar compounds. One of skill will recognize that compounds of the present embodiments may be synthesized using other synthesis schemes. In certain embodiments, a salt corresponding to any of the compounds provided herein is provided. In certain embodiments, a salt corresponding to a selective HGF modulator is provided. In certain embodiments, a salt corresponding to a selective HGF receptor binding agent is provided. In certain embodiments, a salt is obtained by reacting a compound with an acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like. In certain embodiments, a salt is obtained by reacting a compound with a base to form a salt such as an ammonium salt, an alkali metal salt, such as a sodium or a potassium salt, an alkaline earth metal salt, such as a calcium or a magnesium salt, a salt of organic bases such as choline, dicyclohexylamine, N-methyl-D-glucamine, tris(hydroxymethyl)methylamine, 4-(2-hydroxyethyl)-morpholine, 1-(2-hydroxyethyl)-pyrrolidine, ethanolamine and salts with amino acids such as arginine, lysine, and the like. In certain embodiments, a salt is obtained by reacting a free acid form of a selective HGF modulator or selective HGF binding agent with multiple molar equivalents of a base, such as bis-sodium, bis-ethanolamine, and the like. In certain embodiments, a salt corresponding to a compound of the present embodiments is selected from acetate, ammonium, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, calcium edetate, camsylate, carbonate, chloride, cholinate, clavulanate, citrate, dihydrochloride, diphosphate, edetate, edisylate, estolate, esylate, fumarate, gluceptate, gluconate, glutamate, glycollylarsanilate, hexylresorcinate, hydrabanine, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate, lactobionate, laurate, magnesium, malate, maleate, mandelate, mucate, napsylate, nitrate, N-methylglucamine, oxalate, pamoate (embonate), palmitate, pantothenate, phosphate, polygalacturonate, potassium, salicylate, sodium, stearate, subaceatate, succinate, sulfate, tannate, tartrate, teoclate, tosylate, triethiodide, tromethamine, trimethylammonium, and valerate salts. In certain embodiments, one or more carbon atoms of a compound of the present embodiments are replaced with silicon. See e.g., WO 03/037905A1; Tacke and Zilch, Endeavour, New Series, 10, 191-197 (1986); Bains and Tacke, Curr. Opin. Drug Discov Devel. July: 6(4):526-43 (2003), all of which are incorporated herein by reference in their entirety. In certain embodiments, compounds comprising one or more silicon atoms possess certain desired properties, including, but not limited to, greater stability and/or longer half-life in a patient, when compared to the same compound in which none of the carbon atoms have been replaced with a silicon atom. Certain Assays In certain embodiments, assays may be used to determine the level of HGF modulating activity of the compounds of the present embodiments. Proliferation Assay In some embodiments, compounds are tested in an in vitro proliferation assay using the cell lines that express EPO, TPO, GCSF or other cytokine receptors that may be dependant upon these cytokines for their growth. Luciferase Assay In some embodiments, compounds are tested in a reporter assay using the cell lines that express EPO, TPO, GCSF or other cytokine receptors. These cells are transfected with the STAT responsive reporter (such as luciferase) and the activity of the compounds is determined by a reporter assay. Differentiation Assay In some embodiments, compounds are tested in purified human CD34+ progenitor cells. After addition of the compounds to the cells, the number of cells expressing markers of hematopoiesis, erythropoiesis, granulopoiesis, thrombopoiesis, or myelopoiesis is measured by flow cytometry or by analyzing expression of genes associated with these pathways. Certain Pharmaceutical Agents In certain embodiments, at least one selective HGF modulator, or pharmaceutically acceptable salt, ester, amide, and/or prodrug thereof, either alone or combined with one or more pharmaceutically acceptable carriers, forms a pharmaceutical agent. Techniques for formulation and administration of compounds of the present embodiments may be found for example, in “Remington's Pharmaceutical Sciences,” Mack Publishing Co., Easton, Pa., 18th edition, 1990, which is incorporated herein by reference in its entirety. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is prepared using known techniques, including, but not limited to mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or tabletting processes. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is a liquid (e.g., a suspension, elixir and/or solution). In certain of such embodiments, a liquid pharmaceutical agent comprising one or more compounds of the present embodiments is prepared using ingredients known in the art, including, but not limited to, water, glycols, oils, alcohols, flavoring agents, preservatives, and coloring agents. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is a solid (e.g., a powder, tablet, and/or capsule). In certain of such embodiments, a solid pharmaceutical agent comprising one or more compounds of the present embodiments is prepared using ingredients known in the art, including, but not limited to, starches, sugars, diluents, granulating agents, lubricants, binders, and disintegrating agents. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is formulated as a depot preparation. Certain such depot preparations are typically longer acting than non-depot preparations. In certain embodiments, such preparations are administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. In certain embodiments, depot preparations are prepared using suitable polymeric or hydrophobic materials (for example an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments comprises a delivery system. Examples of delivery systems include, but are not limited to, liposomes and emulsions. Certain delivery systems are useful for preparing certain pharmaceutical agents including those comprising hydrophobic compounds. In certain embodiments, certain organic solvents such as dimethylsulfoxide are used. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments comprises one or more tissue-specific delivery molecules designed to deliver the pharmaceutical agent to specific tissues or cell types. For example, in certain embodiments, pharmaceutical agents include liposomes coated with a tissue-specific antibody. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments comprises a co-solvent system. Certain of such co-solvent systems comprise, for example, benzyl alcohol, a nonpolar surfactant, a water-miscible organic polymer, and an aqueous phase. In certain embodiments, such co-solvent systems are used for hydrophobic compounds. A non-limiting example of such a co-solvent system is the VPD co-solvent system, which is a solution of absolute ethanol comprising 3% w/v benzyl alcohol, 8% w/v of the nonpolar surfactant Polysorbate 80™, and 65% w/v polyethylene glycol 300. The proportions of such co-solvent systems may be varied considerably without significantly altering their solubility and toxicity characteristics. Furthermore, the identity of co-solvent components may be varied: for example, other surfactants may be used instead of Polysorbate 80™; the fraction size of polyethylene glycol may be varied; other biocompatible polymers may replace polyethylene glycol, e.g., polyvinyl pyrrolidone; and other sugars or polysaccharides may substitute for dextrose. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments comprises a sustained-release system. A non-limiting example of such a sustained-release system is a semi-permeable matrix of solid hydrophobic polymers. In certain embodiments, sustained-release systems may, depending on their chemical nature, release compounds over a period of hours, days, weeks or months. Certain compounds used in pharmaceutical agent of the present embodiments may be provided as pharmaceutically acceptable salts with pharmaceutically compatible counterions. Pharmaceutically compatible salts may be formed with many acids, including but not limited to hydrochloric, sulfuric, acetic, lactic, tartaric, malic, succinic, etc. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments comprises an active ingredient in a therapeutically effective amount. In certain embodiments, the therapeutically effective amount is sufficient to prevent, alleviate or ameliorate symptoms of a disease or to prolong the survival of the subject being treated. Determination of a therapeutically effective amount is well within the capability of those skilled in the art. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is formulated as a prodrug. In certain embodiments, prodrugs are useful because they are easier to administer than the corresponding active form. For example, in certain instances, a prodrug may be more bioavailable (e.g., through oral administration) than is the corresponding active form. In certain instances, a prodrug may have improved solubility compared to the corresponding active form. In certain embodiments, a prodrug is an ester. In certain embodiments, such prodrugs are less water soluble than the corresponding active form. In certain instances, such prodrugs possess superior transmittal across cell membranes, where water solubility is detrimental to mobility. In certain embodiments, the ester in such prodrugs is metabolically hydrolyzed to carboxylic acid. In certain instances the carboxylic acid containing compound is the corresponding active form. In certain embodiments, a prodrug comprises a short peptide (polyaminoacid) bound to an acid group. In certain of such embodiments, the peptide is metabolized to form the corresponding active form. In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is useful for treating a conditions or disorder in a mammalian, and particularly in a human patient. Suitable administration routes include, but are not limited to, oral, rectal, transmucosal, intestinal, enteral, topical, suppository, through inhalation, intrathecal, intraventricular, intraperitoneal, intranasal, intraocular and parenteral (e.g., intravenous, intramuscular, intramedullary, and subcutaneous). In certain embodiments, pharmaceutical intrathecals are administered to achieve local rather than systemic exposures. For example, pharmaceutical agents may be injected directly in the area of desired effect (e.g., in the renal or cardiac area). In certain embodiments, a pharmaceutical agent comprising one or more compounds of the present embodiments is administered in the form of a dosage unit (e.g., tablet, capsule, bolus, etc.). In certain embodiments, such dosage units comprise a selective HGF modulator in a dose from about 1 μg/kg of body weight to about 50 mg/kg of body weight. In certain embodiments, such dosage units comprise a selective HGF modulator in a dose from about 2 μg/kg of body weight to about 25 mg/kg of body weight. In certain embodiments, such dosage units comprise a selective HGF modulator in a dose from about 10 μg/kg of body weight to about 5 mg/kg of body weight. In certain embodiments, pharmaceutical agents are administered as needed, once per day, twice per day, three times per day, or four or more times per day. It is recognized by those skilled in the art that the particular dose, frequency, and duration of administration depends on a number of factors, including, without limitation, the biological activity desired, the condition of the patient, and tolerance for the pharmaceutical agent. In certain embodiments, a pharmaceutical agent comprising a compound of the present embodiments is prepared for oral administration. In certain of such embodiments, a pharmaceutical agent is formulated by combining one or more compounds of the present embodiments with one or more pharmaceutically acceptable carriers. Certain of such carriers enable compounds of the present embodiments to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient. In certain embodiments, pharmaceutical agents for oral use are obtained by mixing one or more compounds of the present embodiments and one or more solid excipient. Suitable excipients include, but are not limited to, fillers, such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). In certain embodiments, such a mixture is optionally ground and auxiliaries are optionally added. In certain embodiments, pharmaceutical agents are formed to obtain tablets or dragee cores. In certain embodiments, disintegrating agents (e.g., cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof, such as sodium alginate) are added. In certain embodiments, dragee cores are provided with coatings. In certain of such embodiments, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures. Dyestuffs or pigments may be added to tablets or dragee coatings. In certain embodiments, pharmaceutical agents for oral administration are push-fit capsules made of gelatin. Certain of such push-fit capsules comprise one or more compounds of the present embodiments in admixture with one or more filler such as lactose, binders such as starches, and/or lubricants such as talc or magnesium stearate and, optionally, stabilizers. In certain embodiments, pharmaceutical agents for oral administration are soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol. In certain soft capsules, one or more compounds of the present embodiments are be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols. In addition, stabilizers may be added. In certain embodiments, pharmaceutical agents are prepared for buccal administration. Certain of such pharmaceutical agents are tablets or lozenges formulated in conventional manner. In certain embodiments, a pharmaceutical agent is prepared for administration by injection (e.g., intravenous, subcutaneous, intramuscular, etc.). In certain of such embodiments, a pharmaceutical agent comprises a carrier and is formulated in aqueous solution, such as water or physiologically compatible buffers such as Hanks's solution, Ringer's solution, or physiological saline buffer. In certain embodiments, other ingredients are included (e.g., ingredients that aid in solubility or serve as preservatives). In certain embodiments, injectable suspensions are prepared using appropriate liquid carriers, suspending agents and the like. Certain pharmaceutical agents for injection are presented in unit dosage form, e.g., in ampoules or in multi-dose containers. Certain pharmaceutical agents for injection are suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Certain solvents suitable for use in pharmaceutical agents for injection include, but are not limited to, lipophilic solvents and fatty oils, such as sesame oil, synthetic fatty acid esters, such as ethyl oleate or triglycerides, and liposomes. Aqueous injection suspensions may contain substances that increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. Optionally, such suspensions may also contain suitable stabilizers or agents that increase the solubility of the compounds to allow for the preparation of highly concentrated solutions. In certain embodiments, a pharmaceutical agent is prepared for transmucosal administration. In certain of such embodiments penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art. In certain embodiments, a pharmaceutical agent is prepared for administration by inhalation. Certain of such pharmaceutical agents for inhalation are prepared in the form of an aerosol spray in a pressurized pack or a nebulizer. Certain of such pharmaceutical agents comprise a propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In certain embodiments using a pressurized aerosol, the dosage unit may be determined with a valve that delivers a metered amount. In certain embodiments, capsules and cartridges for use in an inhaler or insufflator may be formulated. Certain of such formulations comprise a powder mixture of a compound of the present embodiments and a suitable powder base such as lactose or starch. In certain embodiments, a pharmaceutical agent is prepared for rectal administration, such as a suppositories or retention enema. Certain of such pharmaceutical agents comprise known ingredients, such as cocoa butter and/or other glycerides. In certain embodiments, a pharmaceutical agent is prepared for topical administration. Certain of such pharmaceutical agents comprise bland moisturizing bases, such as ointments or creams. Exemplary suitable ointment bases include, but are not limited to, petrolatum, petrolatum plus volatile silicones, lanolin and water in oil emulsions such as Eucerin™, available from Beiersdorf (Cincinnati, Ohio). Exemplary suitable cream bases include, but are not limited to, Nivea™ Cream, available from Beiersdorf (Cincinnati, Ohio), cold cream (USP), Purpose Cream™, available from Johnson & Johnson (New Brunswick, N.J.), hydrophilic ointment (USP) and Lubriderm™, available from Pfizer (Morris Plains, N.J.). In certain embodiments, the formulation, route of administration and dosage for a pharmaceutical agent of the present embodiments can be chosen in view of a particular patient's condition. (See e.g., Fingl et al. 1975, in “The Pharmacological Basis of Therapeutics”, Ch. 1 p. 1, which is incorporated herein by reference in its entirety). In certain embodiments, a pharmaceutical agent is administered as a single dose. In certain embodiments, a pharmaceutical agent is administered as a series of two or more doses administered over one or more days. In certain embodiments, a pharmaceutical agent of the present embodiments is administered to a patient between about 0.1% and 500%, 5% and 200%, 10% and 100%, 15% and 85%, 25% and 75%, or 40% and 60% of an established human dosage. Where no human dosage is established, a suitable human dosage may be inferred from ED 50 or ID 50 values, or other appropriate values derived from in vitro or in vivo studies. In certain embodiments, a daily dosage regimen for a patient comprises an oral dose of between 0.1 mg and 2000 mg, 5 mg and 1500 mg, 10 mg and 1000 mg, 20 mg and 500 mg, 30 mg and 200 mg, or 40 mg and 100 mg of a compound of the present embodiments. In certain embodiments, a daily dosage regimen is administered as a single daily dose. In certain embodiments, a daily dosage regimen is administered as two, three, four, or more than four doses. In certain embodiments, a pharmaceutical agent of the present embodiments is administered by continuous intravenous infusion. In certain of such embodiments, from 0.1 mg to 500 mg of a composition of the present embodiments is administered per day. In certain embodiments, a pharmaceutical agent of the present embodiments is administered for a period of continuous therapy. For example, a pharmaceutical agent of the present embodiments may be administered over a period of days, weeks, months, or years. Dosage amount, interval between doses, and duration of treatment may be adjusted to achieve a desired effect. In certain embodiments, dosage amount and interval between doses are adjusted to maintain a desired concentration on compound in a patient. For example, in certain embodiments, dosage amount and interval between doses are adjusted to provide plasma concentration of a compound of the present embodiments at an amount sufficient to achieve a desired effect. In certain of such embodiments the plasma concentration is maintained above the minimal effective concentration (MEC). In certain embodiments, pharmaceutical agents of the present embodiments are administered with a dosage regimen designed to maintain a concentration above the MEC for 10-90% of the time, between 30-90% of the time, or between 50-90% of the time. In certain embodiments in which a pharmaceutical agent is administered locally, the dosage regimen is adjusted to achieve a desired local concentration of a compound of the present embodiments. In certain embodiments, a pharmaceutical agent may be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active ingredient. The pack may for example comprise metal or plastic foil, such as a blister pack. The pack or dispenser device may be accompanied by instructions for administration. The pack or dispenser may also be accompanied with a notice associated with the container in form prescribed by a governmental agency regulating the manufacture, use, or sale of pharmaceuticals, which notice is reflective of approval by the agency of the form of the drug for human or veterinary administration. Such notice, for example, may be the labeling approved by the U.S. Food and Drug Administration for prescription drugs, or the approved product insert. Compositions comprising a compound of the present embodiments formulated in a compatible pharmaceutical carrier may also be prepared, placed in an appropriate container, and labeled for treatment of an indicated condition. In certain embodiments, a pharmaceutical agent is in powder form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use. Certain Combination Therapies In certain embodiments, one or more pharmaceutical agents of the present embodiments are co-administered with one or more other pharmaceutical agents. In certain embodiments, such one or more other pharmaceutical agents are designed to treat the same disease or condition as the one or more pharmaceutical agents of the present embodiments. In certain embodiments, such one or more other pharmaceutical agents are designed to treat a different disease or condition as the one or more pharmaceutical agents of the present embodiments. In certain embodiments, such one or more other pharmaceutical agents are designed to treat an undesired effect of one or more pharmaceutical agents of the present embodiments. In certain embodiments, one or more pharmaceutical agents of the present embodiments are co-administered with another pharmaceutical agent to treat an undesired effect of that other pharmaceutical agent. In certain embodiments, one or more pharmaceutical agents of the present embodiments and one or more other pharmaceutical agents are administered at the same time. In certain embodiments, one or more pharmaceutical agents of the present embodiments and one or more other pharmaceutical agents are administered at the different times. In certain embodiments, one or more pharmaceutical agents of the present embodiments and one or more other pharmaceutical agents are prepared together in a single formulation. In certain embodiments, one or more pharmaceutical agents of the present embodiments and one or more other pharmaceutical agents are prepared separately. Examples of pharmaceutical agents that may be co-administered with a pharmaceutical agent of the present embodiments include, but are not limited to, anti-cancer treatments, including, but not limited to, chemotherapy and radiation treatment; corticosteroids, including but not limited to prednisone; immunoglobulins, including, but not limited to intravenous immunoglobulin (IVIg); analgesics (e.g., acetaminophen); anti-inflammatory agents, including, but not limited to non-steroidal anti-inflammatory drugs (e.g., ibuprofen, COX-1 inhibitors, and COX-2, inhibitors); salicylates; antibiotics; antivirals; antifungal agents; antidiabetic agents (e.g., biguanides, glucosidase inhibitors, insulins, sulfonylureas, and thiazolidenediones); adrenergic modifiers; diuretics; hormones (e.g., anabolic steroids, androgen, estrogen, calcitonin, progestin, somatostan, and thyroid hormones); immunomodulators; muscle relaxants; antihistamines; osteoporosis agents (e.g., biphosphonates, calcitonin, and estrogens); prostaglandins, antineoplastic agents; psychotherapeutic agents; sedatives; poison oak or poison sumac products; antibodies; and vaccines. Certain Indications In certain embodiments, provided are methods of treating a patient comprising administering one or more compounds of the present embodiments. In certain embodiments, such patient suffers from thrombocytopenia. In certain such embodiments, thrombocytopenia results from chemotherapy and/or radiation treatment. In certain embodiments, thrombocytopenia results bone marrow failure resulting from bone marrow transplantation and/or aplastic anemia. In certain embodiments thrombocytopenia is idiopathic. In certain embodiments, one or more compounds of the present embodiments are administered to a patient to in conjunction with harvesting peripheral blood progenitor cells and/or in conjunction with platelet apheresis. Such administration may be done before, during, and/or after such harvesting. In certain embodiments, one or more compounds of the present embodiments are administered to a patient who suffers from a condition affecting the nervous system, including, but are not limited to, diseases affecting the nervous system and injuries to the nervous system. Such diseases, include, but not limited to, amyotrophic lateral sclerosis, multiple sclerosis, and multiple dystrophy. Injury to the nervous system include, but are not limited to spinal cord injury or peripheral nerve damage, including, but not limited to, injury resulting from trauma or from stroke. In certain embodiments, one or more compounds of the present embodiments are used to promote growth and/or development of glial cells. Such glial cells may repair nerve cells. In certain embodiments, compounds of the present embodiments are used to treat psychological disorders, including, but not limited to, cognitive disorders. EXAMPLES The following examples are set forth merely to assist in understanding the embodiments and should not be construed as limiting the embodiments described and claimed herein in any way. Variations of the invention, including the substitution of all equivalents now known or later developed, which would be within the purview of those skilled in the art, and changes in formulation or minor changes in experimental design, are to be considered to fall within the scope of the invention incorporated herein. Example 1 4-(4-Hydroxyphenyl)hydrazono-1-(4-phenylthiazolyl-2)-3-methyl-5-pyrazolone (Compound 101) Compound 101 above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-phenylthiazolyl-2)-5-pyrazolone. The molecular weight for C 19 H 15 N 5 O 2 S is 377.42; m/z 378.02 (MH + ). Example 2 4-(4-Hydroxyphenyl)hydrazono-1-(2-pyridyl)-3-methyl-5-pyrazolone (Compound 102) Compound 102 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 2-pyridylhydrazine. The molecular weight of C 15 H 13 N 5 O 2 is 295.30; m/z (MH + ): calculated 296.11 and observed 296.10. Example 3 4-(4-Hydroxyphenyl)hydrazono-1-(5-methyl-2-pyridyl)-3-methyl-5-pyrazolone (Compound 103) Compound 103 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 5-methyl-2-pyridylhydrazine. The molecular weight of C 16 H 15 N 5 O 2 : is 309.32; m/z (MH + ): calculated 310.13 and observed 310.09. Example 4 4-(4-Hydroxyphenyl)hydrazono-1-(4-(4-methylphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 104) Compound 104 above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-(4-methylphenyl)thiazolyl-2)-5-pyrazolone. The molecular weight of C 20 H 17 N 5 O 2 S: 391.45 is m/z (MH + ): calculated 392.11 and observed 392.04. Example 5 4-(4-Hydroxyphenyl)hydrazono-1-(4-(3-methoxyphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 105) Compound 105 above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-(3-methoxyphenyl)thiazolyl-2)-5-pyrazolone. The molecular weight of C 20 H 17 N 5 O 3 S is 407.45; m/z (MH + ): calculated 408.11 and observed 408.03. Example 6 4-(4-Hydroxyphenyl)hydrazono-1-(4-(3-methylphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 106) Compound 106 above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-(3-methylphenyl)thiazolyl-2)-5-pyrazolone. 1 H NMR (500 MHz, CD 3 OD) 7.84 (s, 1H), 7.76 (d, 1H), 7.50 (s, 1H), 7.46 (d, 2H), 7.29 (t, 1H), 7.15 (d, 1H), 6.89 (d, 2H), and 2.41 (s, 6H). Example 7 4-(4-Hydroxyphenyl)hydrazono-1-(4-(2-methylphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 107) Compound 107 above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-(2-methylphenyl)thiazolyl-2)-5-pyrazolone. The molecular weight of C 20 H 17 N 5 O 2 S is 391.45; m/z (MH + ): calculated 392.11 and observed 392.04. Example 8 4-(4-Hydroxyphenyl)hydrazono-1-(2-quinolino)-3-methyl-5-pyrazolone (Compound 108) Compound 108 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 2-quinolinohydrazine. 1 H NMR (500 MHz, CD 3 OD) 8.40 (d, 1H), 8.33 (d, 1H), 8.08 (d, 1H), 7.91 (d, 1H), 7.75 (t, 1H), 7.56 (t, 1H), 7.46 (d, 2H), 6.90 (d, 2H), and 2.43 (s, 3H). Example 9 4-(4-Hydroxyphenyl)hydrazono-1-(4-(2-methoxyphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 109) Compound 109 above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-(2-methoxyphenyl)thiazolyl-2)-5-pyrazolone. The 1 H NMR spectrum (500 MHz, CDCl 3 ) 8.38 (dd, 1H), 7.80 (s, 1H), 7.39 (d, 2H), 7.30 (t, 1H), 7.06 (t, 1H), 6.99 (d, 1H), 6.93 (d, 2H), 3.98 (s, 3H), and 2.47 (s, 3H). Example 10 4-(4-Hydroxyphenyl)hydrazono-1-(4-methylquinolino-2)-3-methyl-5-pyrazolone (Compound 110) Compound 110 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 2-(4-methylquinolino)hydrazine. The molecular weight of C 20 H 17 N 5 O 2 is 359.38; m/z (MH + ): calculated 360.14 and observed 360.07. Example 11 4-(4-Hydroxyphenyl)hydrazono-1-(4-(2-methoxyphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound III) Compound III above was prepared according to the procedure described in Scheme IV above from 4-hydroxyaniline and (4-(2-methoxyphenyl)thiazolyl-2)-5-pyrazolone. The molecular weight of C 17 H 13 N 5 O 2 S 2 is 383.45; m/z (MH + ): calculated 384.05 and observed 384.01. Example 12 4-(4-Hydroxy-3-methoxyphenyl)hydrazono-1-(4-(4-methylphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 112) Compound 112 above was prepared according to the procedure described in Scheme IV above from 4-hydroxy-3-methoxyaniline and (4-(4-methylphenyl)thiazolyl-2)-5-pyrazolone. The molecular weight of C 21 H 12 N 5 O 3 S is 421.47; m/z (MH + ): calculated 422.12 and observed 421.99. Example 13 4-(4-Hydroxy-3-methylphenyl)hydrazono-1-(4-(4-methylphenyl)thiazolyl-2)-3-methyl-5-pyrazolone (Compound 113) Compound 113 above was prepared according to the procedure described in Scheme IV above from 4-hydroxy-3-methylaniline and (4-(4-methylphenyl)thiazolyl-2)-5-pyrazolone. The molecular weight of C 21 H 12 N 5 O 2 S is 405.47; m/z (MH + ): calculated 406.13 and observed 406. Example 14 4-(3-Amino-4-hydroxyphenyl)hydrazono-1-phenyl-3-methyl-5-pyrazolone (Compound 114) Compound 114 above was prepared according to the procedure described in Scheme III above from 3-amino-4-hydroxyaniline and phenylhydrazine. The molecular weight of C 16 H 15 N 5 O 2 is 309.32; m/z (MH + ): calculated 310.13 and observed 310.05. Example 15 4-(4-Hydroxyphenyl)hydrazono-1-(3-methyl)phenyl-3-methyl-5-pyrazolone (Compound 115) Compound 115 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 3-methylphenylhydrazine. 1 H NMR (CDCl 3 , 300 MHz) 7.89 (d, 2H), 7.76-7.64 (m 2H), 7.36-7.29 (m, 1H), 7.05 (d, 1H), 6.91 (d, 2H), 5.49 (br s, 1H), 2.39 (s, 3H), 2.32 (s, 3H). Example 16 4-(4-Hydroxyphenyl)hydrazono-1-(3-ethyl)phenyl-3-methyl-5-pyrazolone (Compound 116) Compound 116 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 3-ethylphenylhydrazine. The molecular weight of C 18 H 18 N 4 O 2 is 322.36; m/z (MH + ): calculated 423.14 and observed 423.14. Example 17 4-(4-Hydroxyphenyl)hydrazono-1-(5-indanyl)-3-methyl-5-pyrazolone (Compound 117) Compound 117 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 5-indanylhydrazine. 1 H NMR (CDCl 3 , 300 MHz) 7.76 (br s, 1H), 7.67 (d, 1H), 7.35 (d, 1H), 6.93 (d, 2H), 5.07 (br s, 1H), 2.97-2.88 (m, 4H), 2.35 (s, 3H), 2.12-2.07 (m, 2H). Example 18 4-(4-Hydroxyphenyl)hydrazono-1-(4-methyl-2-pyridyl)-3-methyl-5-pyrazolone (Compound 118) Compound 118 above was prepared according to the procedure described in Scheme III above from 4-hydroxyaniline and 4-methyl-2-pyridylhydrazine. 1 H NMR (500 MHz, DMSO) 8.30 (d, 1H), 7.72 (s, 1H), 7.45 (d, 2H), 7.10 (d, 1H), 6.84 (d, 2H), 2.36 (s, 3H), 2.27 (s, 3H). Example 19 6-Fluoro-3-(4-hydroxyphenyl)hydrazono-1-(6-methyl-2-pyridyl)oxindole (Compound 119) Compound 119 above was prepared according to the procedure described in Scheme II from 4-hydroxyaniline and 5-fluoro-1-(6-methylpyridinyl)oxindole. 1 H NMR (DMSO, 500 MHz) 12.64 (s), 9.40 (s), 7.91 (t), 7.68 (d), 7.29 (d), and 2.57 (s). Example 20 6-Fluoro-3-(4-hydroxyphenyl)hydrazono-1-(3-methylphenyl)oxindole (Compound 120) Compound 120 above was prepared according to the procedure described in Scheme II from 4-hydroxyaniline and 5-fluoro-1-(3-methylphenyl)oxindole. 1 H NMR (CDCl 3 , 500 MHz) 12.81 (s), 5.05 (s), and 2.42 (s). Example 21 (1-Methyl-5-methoxyindole-2-)carboxyl(4-hydroxybenzylidene)hydrazide (Compound 121) Compound 121 above was prepared according to the procedure described in Scheme VI above from 4-hydroxybenzaldehyde and 1-methyl-5-methoxyindole-2-carboxylic acid. The molecular weight of C 18 H 17 N 3 O 3 is 323.35; m/z 324.13 (MH + ). Example 22 4-(2-Oxopyrrolidino-1-)benz(3-methoxybenzylidene)hydrazide (Compound 122) Compound 122 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 19 H 19 N 3 O 3 is 337.37; m/z 338.15 (MH + ). Example 23 4-(2-Oxopyrrolidino-1-)benz(2-hydroxybenzylidene)hydrazide (Compound 123) Compound 123 above was prepared according to the procedure described in Scheme VI above from 2-hydroxybenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 18 H 17 N 3 O 3 is 323.35; m/z 324.13 (MH + ). Example 24 3-Methylbenz(2-hydroxybenzylidene)hydrazide (Compound 124) Compound 124 above was prepared according to the procedure described in Scheme VI above from 2-hydroxybenzaldehyde and 3-methylbenzoic acid. The molecular weight of C 15 H 14 N 2 O 2 is 254.28; m/z 255.11 (MH + ). Example 25 4-Phenylbenz(2-naphthylidene)hydrazide (Compound 125) Compound 125 above was prepared according to the procedure described in Scheme VI above from 2-naphthaldehyde and 4-phenylbenzoic acid. The molecular weight of C 24 H 18 N 2 O is 350.41; m/z 351.15 (MH + ). Example 26 4-Hydroxybenz(2-naphthylidene)hydrazide (Compound 126) Compound 126 above was prepared according to the procedure described in Scheme VI above from 2-naphthaldehyde and 4-hydroxybenzoic acid. The molecular weight of C 18 H 14 N 2 O 2 is 290.32; m/z 291.11 (MH + ). Example 27 4-(2-Oxopyrrolidino-1-)benz(4-dimethylaminobenzylidene)hydrazide (Compound 127) Compound 127 above was prepared according to the procedure described in Scheme VI above from 4-dimethylaminobenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 20 H 22 N 4 O 2 is 350.41; m/z 351.18 (MH + ). Example 28 4-Methoxybenz(3-methoxybenzylidene)hydrazide (Compound 128) Compound 128 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-methoxybenzoic acid. The molecular weight of C 16 H 16 N 2 O 3 is 284.31; m/z 285.12 (MH + ). Example 29 4-(2-Oxopyrrolidino-1-)benz(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 129) Compound 129 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 19 H 19 N 3 O 4 is 353.37; m/z 354.14 (MH + ). Example 30 4-(2-Oxopyrrolidino-1-)benz(4-hydroxy-3-methoxybenzylidene)hydrazide (Compound 130) Compound 130 above was prepared according to the procedure described in Scheme VI above from 4-hydroxy-3-methoxybenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 19 H 19 N 3 O 4 is 353.37; m/z 354.14 (MH + ). Example 31 4-(2-Oxopyrrolidino-1-)benz(4-methoxybenzylidene)hydrazide (Compound 131) Compound 131 above was prepared according to the procedure described in Scheme VI above from 4-methoxybenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 19 H 19 N 3 O 3 is 337.37; m/z 33815 (MH + ). Example 32 4-(2-Oxopyrrolidino-1-)benz(3,4-dimethoxybenzylidene)hydrazide (Compound 132) Compound 132 above was prepared according to the procedure described in Scheme VI above from 3,4-dimethoxybenzaldehyde and 4-(2-oxopyrrolidino-1-)benzoic acid. The molecular weight of C 20 H 21 N 3 O 4 is 367.15; m/z 368.16 (MH + ). Example 33 4-(4-Chlorobenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 133) Compound 133 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-chlorobenzyloxy)benzoic acid. The molecular weight of C 22 H 19 ClN 2 O 3 is 394.11; m/z 396.11 (MH + ). Example 34 4-(4-Methylbenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 134) Compound 134 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-methylbenzyloxy)benzoic acid. The molecular weight of C 23 H 22 N 2 O 3 is 374.16; m/z 375.17 (MH + ). Example 35 4-(1-Pyrrolyl)benz(3-methoxybenzylidene)hydrazide (Compound 135) Compound 135 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(1-pyrrolyl)benzoic acid. The molecular weight of C 19 H 17 N 3 O 2 is 319.36; m/z 320.14 (MH + ). Example 36 4-(4-Methylbenzyloxy)benz(3,4,5-trimethoxybenzylidene)hydrazide (Compound 136) Compound 136 above was prepared according to the procedure described in Scheme VI above from 3,4,5-trimethoxybenzaldehyde and 4-(4-methylbenzyloxy)benzoic acid. The molecular weight of C 25 H 26 N 2 O 5 is 434.48; m/z 435.19 (MH + ). Example 37 4-(4-Chlorobenzyloxy)benz(3,4-dimethoxybenzylidene)hydrazide (Compound 137) Compound 137 above was prepared according to the procedure described in Scheme VI above from 3,4-dimethoxybenzaldehyde and 4-(4-chlorobenzyloxy)benzoic acid. The molecular weight of C 23 H 21 ClN 2 O 4 is 424.88; m/z 426.12 (MH + ). Example 38 4-(4-Methylbenzyloxy)benz(3,4-dimethoxybenzylidene)hydrazide (Compound 138) Compound 138 above was prepared according to the procedure described in Scheme VI above from 3,4-dimethoxybenzaldehyde and 4-(4-methylbenzyloxy)benzoic acid. The molecular weight of C 24 H 24 N 2 O 4 is 404.46; m/z 405.18 (MH + ). Example 39 4-Dimethylaminobenz(3-methoxybenzylidene)hydrazide (Compound 139) Compound 139 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-dimethylaminobenzoic acid. The molecular weight of C 17 H 19 N 3 O 2 is 297.35; m/z 298.15 (MH + ). Example 40 4-Phenylbenz(3-methoxybenzylidene)hydrazide (Compound 140) Compound 140 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-phenylbenzoic acid. The molecular weight of C 21 H 18 N 2 O 2 is 330.38; m/z 331.14 (MH + ). Example 41 4-(4-Chlorobenzyloxy)benz(4-hydroxy-3-methoxybenzylidene)hydrazide (Compound 141) Compound 141 above was prepared according to the procedure described in Scheme VI above from 4-hydroxy-3-methoxybenzaldehyde and 4-(4-chlorobenzyloxy)benzoic acid. The molecular weight of C 22 H 19 ClN 2 O 4 is 410.85; m/z 412.10 (MH + ). Example 42 4-(4-Bromobenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 142) Compound 142 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-bromobenzyloxy)benzoic acid. The molecular weight of C 22 H 19 BrN 2 O 3 is 439.30; m/z 438.06 (MH + ). Example 43 4-(4-Fluorobenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 143) Compound 143 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-fluorobenzyloxy)benzoic acid. The molecular weight of C 22 H 19 FN 2 O 3 is 378.40; m/z 379.14 (MH + ). Example 44 4-Phenylbenz(4-hydroxy-3-methoxybenzylidene)hydrazide (Compound 144) Compound 144 above was prepared according to the procedure described in Scheme VI above from 4-hydroxy-3-methoxybenzaldehyde and 4-phenylbenzoic acid. The molecular weight of C 21 H 18 N 2 O 3 is 346.38; m/z 347.14 (MH + ). Example 45 4-Diethylaminobenz(3-methoxybenzylidene)hydrazide (Compound 145) Compound 145 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-diethylaminobenzoic acid. The molecular weight of C 19 H 23 N 3 O 2 is 325.40; m/z 326.18 (MH + ). Example 46 3-(2-Naphthylpyrazolyl-5-)carboxyl(3-methoxybenzylidene)hydrazide (Compound 146) Compound 146 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 3-(2-Naphthylpyrazolyl-5-)carboxylic acid. The molecular weight of C 22 H 18 N 4 O 2 is 370.40; m/z 371.15 (MH + ). Example 47 3-(4-(2-Methylpropyl)phenylpyrazolyl-5-)carboxyl(3-methoxybenzylidene)hydrazide (Compound 147) Compound 147 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 3-(4-(2-methylpropyl)phenylpyrazolyl-5-)carboxylic acid. The molecular weight of C 22 H 24 N 4 O 2 is 376.45; m/z 377.19 (MH + ). Example 48 Octadecano(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 148) Compound 148 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and octadecanolic acid. The molecular weight of C 26 H 44 N 2 O 3 is 432.64; m/z? (MH + ). Example 49 4-Benzyloxybenz(3-methoxybenzylidene)hydrazide (Compound 149) Compound 149 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-benzyloxybenzoic acid. The molecular weight of C 22 H 20 N 2 O 3 is 360.41; m/z 361.15 (MH + ). Example 50 4-(4-Oxazolyl)benz(3-methoxybenzylidene)hydrazide (Compound 150) Compound 150 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-oxazolyl)benzoic acid. 1 H NMR (500 MHz, DMSO) 8.53 (s, 1H), 8.44 (s, 1H), 8.01 (d, 2H), 7.88 (m, 3H), 7.38 (m, 1H), 7.28 (m, 2H), 7.02 (m, 1H), 3.81 (s, 3H). Example 51 4-Phenylbenz(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 151) Compound 151 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and 4-phenylbenzoic acid. 1 H NMR (500 MHz, DMSO) 8.64 (s, 1H), 8.02 (d, 2H), 7.84 (d, 2H), 7.76 (d, 2H), 7.50 (m, 2H), 7.42 (m, 1H), 7.13 (d, 1H), 6.84-6.92 (m, 2H), 3.73 (s, 3H). Example 52 4-(4-Methoxybenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 152) Compound 152 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-methoxybenzyloxy)benzoic acid. The molecular weight of C 23 H 22 N 2 O 4 is 390.43; m/z (MH + ): calculated 391.16 and observed 391.10. Example 53 4-(3-Chlorobenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 153) Compound 153 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(3-chlorobenzyloxy)benzoic acid. 1 H NMR (500 MHz, CD3OD) 8.28 (s, 1H), 7.93 (m, 2H), 7.56 (br, 1H), 7.49 (m, 1H), 7.26-7.40 (m, 5H), 7.13 (m, 2H), 6.98 (m, 1H), 5.19 (s, 2H), 3.86 (s, 3H). Example 54 4-(4-Trifluoromethylbenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 154) Compound 154 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-Trifluoromethylbenzyloxy)benzoic acid. 1 H NMR (500 MHz, CD 3 COCD 3 ) 8.46 (br, 1H), 8.00 (d, 2H), 7.76 (m, 4H), 7.24-7.36 (m, 3H), 7.15 (d, 2H), 6.98 (m, 1H), 5.35 (s, 2H), 3.83 (s, 3H). Example 55 4-(3-Methoxybenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 155) Compound 155 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(3-methoxybenzyloxy)benzoic acid. 1 H NMR (500 MHz, CD 3 COCD 3 ) 8.54 (br, 1H), 8.04 (m, 2H), 7.22-7.34 (m, 4H), 7.09 (d, 2H), 7.04 (m, 2H), 6.88-6.94 (m, 2H), 5.14 (s, 2H), 3.79 (s, 3H), 3.76 (s, 3H). Example 56 4-(4-Vinylbenzyloxy)benz(3-methoxybenzylidene)hydrazide (Compound 156) Compound 156 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(4-vinylbenzyloxy)benzoic acid. The molecular weight of C 24 H 22 N 2 O 3 is 386.44; m/z (MO: calculated 387.17 and observed 387.00. Example 57 4-(2-Naphthylmethoxy)benz(3-methoxybenzylidene)hydrazide (Compound 157) Compound 157 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(2-naphthylmethoxy)benzoic acid. The molecular weight of C 26 H 22 N 2 O 3 is 410.46; m/z (MH + ): calculated 411.17 and observed 411.00. Example 58 4-((2-Phenylthiazolyl-4-)methoxy)benz(3-methoxybenzylidene)hydrazide (Compound 158) Compound 158 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-((2-phenylthiazolyl-4-)methoxy)benzoic acid. 1 H NMR (500 MHz, CD 3 COCD 3 ) 8.46 (br, 1H), 8.01 (d, 2H), 7.99 (m, 2H), 7.50 (m, 3H), 7.34 (t, 2H), 7.27 (m, 1H), 7.17 (d, 2H), 6.98 (m, 1H), 5.45 (s, 2H), 3.84 (s, 3H), 2.51 (s, 3H). Example 59 4-Phenylbenz(4-fluoro-3-methoxybenzylidene)hydrazide (Compound 159) Compound 159 above was prepared according to the procedure described in Scheme VI above from 4-fluoro-3-methoxybenzaldehyde and 4-phenylbenzoic acid. The molecular weight of C 21 H 17 F 2 O 2 is 348.37; m/z (MH + ): calculated 349.13 and observed 349.14. Example 60 4-Phenylbenz(3,5-dimethoxybenzylidene)hydrazide (Compound 160) Compound 160 above was prepared according to the procedure described in Scheme VI above from 3,5-dimethoxybenzaldehyde and 4-phenylbenzoic acid. The molecular weight of C 22 H 20 N 2 O 3 is 360.41; m/z (MH + ): calculated 361.15 and observed 361.15. Example 61 4-(2-Fluorophenyl)phenylbenz(3-methoxybenzylidene)hydrazide (Compound 161) Compound 161 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(2-fluorophenyl)benzoic acid, The molecular weight of C 21 H 17 F 2 O 2 is 348.37; m/z (MH + ): calculated 349.13 and observed 349.10. Example 62 4-Methylaminobenz(3-methoxybenzylidene)hydrazide (Compound 162) Compound 162 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-methylaminobenzoic acid. The molecular weight of C 16 H 17 N 3 O 2 is 283.33; m/z (MH + ): calculated 284.14 and observed 284.10. Example 63 4-Phenylbenz(5-indolidene)hydrazide (Compound 163) Compound 163 above was prepared according to the procedure described in Scheme VI above from 4-phenylbenzoic acid and 5-indolecarboxaldehyde. The molecular weight of C 22 H 17 N 3 O is 339.39; m/z 340.14 (MH + ). Example 64 4-Phenylbenz(3-vinylbenzylidene)hydrazide (Compound 164) Compound 164 above was prepared according to the procedure described in Scheme VI above from 3-vinylbenzaldehyde and 4-phenylbenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.94 (s), 8.49 (s), 8.02 (d), 5.90 (d), and 5.35 (d). Example 65 4-Phenylbenz(3-acetylbenzylidene)hydrazide (Compound 165) Compound 165 above was prepared according to the procedure described in Scheme VI above from 3-acetylbenzaldehyde and 4-phenylbenzoic acid. 1 H NMR (CDCl 3 , 500 MHz) 10.49 (s), 8.57 (s), 8.13 (s), and 2.54 (s). Example 66 4-Dimethylaminobenz(3-acetylbenzylidene)hydrazide (Compound 166) Compound 166 above was prepared according to the procedure described in Scheme VI above from 3-acetylbenzaldehyde and 4-dimethylaminobenzoic acid. NMR (DMSO, 500 MHz) 11.63 (s), 8.49 (s), 8.23 (s), 7.99 (d), 7.94 (d), 7.82 (d), 7.60 (t), and 6.75 (d). Example 67 4-Dimethylaminobenz(3-vinylbenzylidene)hydrazide (Compound 167) Compound 167 above was prepared according to the procedure described in Scheme VI above from 3-vinylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.58 (s), 8.42 (s), 7.82 (d), 7.25 (s), 7.60 (d), 7.53 (d), 7.42 (t), and 2.99 (s). Example 68 4-Dimethylaminobenz(3-methoxybenzylidene)hydrazide (Compound 168) Compound 168 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (500 MHz, CDCl 3 ) 7.29 (d, J 8.0, 1H), 7.24 (d, J 8.0, 1H), 7.08-7.05 (m, 3H), 7.01 (d, J 7.5, 1H), 6.88 (ddd, J 7.5, 6.5 and 1.5, 1H), 6.77 (dd, J 8.5 and 2.5, 1H), 6.33 (s, 1H), 3.81 (s, 3H), 2.98 (s, 6H). Example 69 4-Dimethylaminobenz(3-phenylacetylenebenzylidene)hydrazide (Compound 169) Compound 169 above was prepared according to the procedure described in Scheme VI above from 3-phenylacetylenebenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (500 MHz, DMSO) 11.64 (s, 1H), 8.42 (s, 1H), 7.88 (s, 1H), 7.82 (d, J 7.5, 2H), 7.73 (d, J 8.0, 1H), 7.61-7.57 (m, 3H), 7.51 (t, J 7.5, 1H), 7.45-7.43 (m, 3H), 6.76 (d, J 9.0, 2H), and 3.00 (s, 6H). Example 70 4-Dimethylaminobenz(3-(2E-phenylethenyl)benzylidene)hydrazide (Compound 170) Compound 170 above was prepared according to the procedure described in Scheme VI above from 3-(2E-phenylethenyl)benzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (500 MHz, DMSO) 11.58 (s, 1H), 8.45 (s, 1H), 7.83 (d, J 8.5, 2H), 7.68-7.64 (m, 2H), 7.60 (d, J 7.5, 2H), 7.46 (t, J 7.5, 1H), 7.39 (t, J 8.0, 2H), 7.33 (d, J 4.0, 2H), 7.29 (t, J 7.5, 1H) 6.76 (d, J 9.0, 2H), and 3.00 (s, 6H). Example 71 4-Dimethylaminobenz(3-hydroxymethylbenzylidene)hydrazide (Compound 171) Compound 171 above was prepared according to the procedure described in Scheme VI above from 3-hydroxymethylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (500 MHz, DMSO) 11.52 (s, 1H), 8.41 (s, 1H), 7.82 (d, J 9.0, 2H), 7.69 (s, 1H), 7.53 (d, J 8.0, 1H), 7.39 (t, J 7.5, 1H), 7.34 (d, J 7.5, 1H), 6.75 (d, J 9.0, 2H), 4.55 (d, J 5.5, 2H), and 2.99 (s, 6H). Example 72 5-Methoxyindole-2-carboxyl(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 172) Compound 172 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and 5-methoxyindole-2-carboxylic acid. The molecular weight of C 18 H 17 N 3 O 4 is 339.35; m/z (M + ): calculated 340.12 and observed 340.06. Example 73 5-Indolyloxoacet(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 173) Compound 173 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and 5-indolyloxoacetic acid. The molecular weight of C 18 H 17 N 3 O 4 is 339.35; m/z (MH + ): calculated 340.13 and observed 399.99. Example 74 5-Hydroxybenzofuran-2-carboxyl(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 174) Compound 174 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and 5-hydroxybenzofuran-2-carboxylic acid. The molecular weight of C 17 H 14 N 2 O 5 is 326.30; m/z (MH + ): calculated 327.09 and observed 326.98. Example 75 5-Hydroxyindole-2-carboxyl(2-hydroxy-5-methoxybenzylidene)hydrazide (Compound 175) Compound 175 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-5-methoxybenzaldehyde and 5-hydroxyindole-2-carboxylic acid. The molecular weight of C 17 H 15 N 3 O 4 is 325.32; m/z (MH + ): calculated 326.11 and observed 325.90. Example 76 5-Hydroxybenzofuran-2-carboxyl(3-methoxymethylbenzylidene)hydrazide (Compound 176) Compound 176 above was prepared according to the procedure described in Scheme VI above from 3-methoxymethylbenzaldehyde and 5-hydroxybenzofuran-2-carboxylic acid. The molecular weight of C 18 H 16 N 2 O 4 is 324.33; m/z (MH + ): calculated 325.11 and observed 324.96. Example 77 4-Dimethylaminobenz(3-dimethylaminobenzylidene)hydrazide (Compound 177) Compound 177 above was prepared according to the procedure described in Scheme VI above from 3-dimethylaminobenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.43 (s), 8.36 (s), 7.80 (d), 7.24 (t), 7.01 (s), 6.74 (d), 2.99 (s), and 2.96 (s). Example 78 4-Dimethylaminobenz(3-bromo-5-indolidene)hydrazide (Compound 178) Compound 178 above was prepared according to the procedure described in Scheme VI above from 4-dimethylaminobenzoic acid and 3-bromo-5-indolecarboxaldehyde. 1 H NMR (DMSO, 500 MHz) 11.68 (s), 11.43 (s), 8.50 (s), 7.82 (d), 7.68 (s), 7.48 (d), 6.75 (d), and 2.99 (s). Example 79 4-Dimethylaminobenz(2E-ethylaminocarboxyethenylbenzylidene)hydrazide (Compound 179) Compound 179 above was prepared according to the procedure described in Scheme VI above from 2E-ethylaminocarboxyethenylbenzaldehyde and 4-dimethylaminobenzoic acid. The molecular weight of C 21 H 24 N 4 O 2 is 364.44; m/z (MH + ): calculated 365.19 and observed 365.06. Example 80 4-Dimethylaminobenz(3-chloro-6-indolidene)hydrazide (Compound 180) Compound 180 above was prepared according to the procedure described in Scheme VI above from 4-dimethylaminobenzoic acid and 3-chloro-6-indolecarboxaldehyde. 1 H NMR (DMSO, 500 MHz) 11.58 (s), 11.43 (s), 8.48 (s), 7.81 (d), 7.74 (s), 7.62 (d), 7.46 (d), 6.74 (d), and 2.99 (s). Example 81 4-Dimethylaminobenz(2E-(2-methylphenyl)ethenylbenzylidene)hydrazide (Compound 181) Compound 181 above was prepared according to the procedure described in Scheme VI above from 2E-(2-methylphenyl)ethenylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.59 (s), 8.46 (s), 7.88 (s), 7.82 (d), 7.61 (d), 6.75 (d), 2.99 (s), and 2.41 (s). Example 82 4-Dimethylaminobenz(2E-(3-chlorophenyl)ethenylbenzylidene)hydrazide (Compound 182) Compound 182 above was prepared according to the procedure described in Scheme VI above from 2E-(3-chlorophenyl)ethenylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.59 (s), 8.44 (s), 7.89 (s), 7.82 (d), 6.76 (d), and 2.99 (s). Example 83 4-Dimethylaminobenz(2E-(4-hydroxybutyl)aminocarboxyethenylbenzylidene)hydrazide (Compound 183) Compound 183 above was prepared according to the procedure described in Scheme VI above from 2E-(4-hydroxybutyl)aminocarboxyethenylbenzaldehyde and 4-dimethylaminobenzoic acid. The molecular weight of C 23 H 28 N 4 O 3 is 408.49; m/z (MH + ): calculated 409.22 and observed 409.04. Example 84 4-Dimethylaminobenz(3-benzyloxymethylbenzylidene)hydrazide (Compound 184) Compound 184 above was prepared according to the procedure described in Scheme VI above from 3-benzyloxymethylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.57 (s), 8.41 (s), 7.81 (d), 6.74 (d), 4.59 (s), 4.58 (s), and 2.99 (s). Example 85 4-Dimethylaminobenz(2E-(2-chlorophenyl)ethenylbenzylidene)hydrazide (Compound 185) Compound 185 above was prepared according to the procedure described in Scheme VI above from 2E-(2-chlorophenyl)ethenylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.59 (s), 8.43 (s), 7.82 (d), 7.68 (d), 7.63 (d), 6.75 (d), and 2.99 (s). Example 86 4-Dimethylaminobenz(2E-(4-chlorophenyl)ethenylbenzylidene)hydrazide (Compound 186) Compound 186 above was prepared according to the procedure described in Scheme VI above from 2E-(4-chlorophenyl)ethenylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.59 (s), 8.44 (s), 7.89 (s), 7.67 (d), 7.60 (d), 6.76 (d), and 2.99 (s). Example 87 4-Dimethylaminobenz(3-methoxymethylbenzylidene)hydrazide (Compound 187) Compound 187 above was prepared according to the procedure described in Scheme VI above from 3-methoxymethylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (500 MHz, DMSO) 11.58 (s, 1H), 8.44 (s, 1H), 7.83 (d, J 9.5, 2H), 7.68 (s, 1H), 7.58 (d, J 7.5, 1H), 7.43 (t, J 7.5, 1H), 7.35 (d, J 7.5, 1H), 6.75 (d, J 7.5, 2H), 4.46 (s, 2H), 3.32 (s, 3H), and 2.99 (s, 6H). Example 88 4-Dimethylaminobenz(3-(2-methylbenzyloxy)methylbenzylidene)hydrazide (Compound 188) Compound 188 above was prepared according to the procedure described in Scheme VI above from 3-(2-methylbenzyloxy)methylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (CDCl 3 , 500 MHz) 7.68 (d), 4.59 (s), 4.58 (s), 3.02 (s), and 2.32 (s). Example 89 4-Dimethylaminobenz(3-(4-methylbenzyloxy)methylbenzylidene)hydrazide (Compound 189) Compound 189 above was prepared according to the procedure described in Scheme VI above from 3-(4-methylbenzyloxy)methylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (CDCl 3 , 500 MHz) 6.70 (d), 4.57 (s), 4.56 (s), 3.04 (s), and 2.34 (s). Example 90 4-Dimethylaminobenz(3-benzyloxyiminomethylbenzylidene)hydrazide (Compound 190) Compound 190 above was prepared according to the procedure described in Scheme VI above from 3-benzyloxyiminomethylbenzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.59 (s), 8.42 (s), 8.38 (s), 7.97 (s), 7.81 (d), 7.68 (d), 7.62 (d), 7.48 (t), 6.75 (d), and 5.20 (s). Example 91 4-(1-Imidazolyl)benz(2E-(2-chlorophenyl)ethenylbenzylidene)hydrazide (Compound 191) Compound 191 above was prepared according to the procedure described in Scheme VI above from 2E-(2-chlorophenyl)ethenylbenzaldehyde and 1-imidazolylbenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.97 (s), 8.52 (s), 8.41 (s), 8.07 (d), 7.97 (s), 7.92 (d), 7.72 (d), 7.68 (d), and 7.15 (s). Example 92 4-Dimethylaminobenz(3-allyloxyiminomethylbenzylidene)hydrazide (Compound 192) Compound 192 above was prepared according to the procedure described in Scheme VI above from 3-allyloxyiminomethylbenzaldehyde and 4-dimethylaminobenzoic acid. The molecular weight of C 20 H 22 N 4 O 2 is 350.41; m/z 351.18 (MH + ). Example 93 4-(1-Imidazolyl)benz(3-methoxybenzylidene)hydrazide (Compound 193) Compound 193 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 1-imidazolylbenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.91 (s), 8.42 (d), 8.07 (d), 7.38 (t), 7.13 (s), 7.01 (d), and 3.80 (s). Example 94 4-(1-Imidazolyl)benz(3-benzyloxyiminomethylbenzylidene)hydrazide (Compound 194) Compound 194 above was prepared according to the procedure described in Scheme VI above from 3-benzyloxyiminomethylbenzaldehyde and 4-(1-imidazolyl)benzoic acid. The molecular weight of C 25 H 21 N 5 O 2 is 423.47; m/z (MH + ): calculated 424.17 and observed 424 Example 95 4-Dimethylaminobenz(3-(2-hydroxyethoxy)benzylidene)hydrazide (Compound 195) Compound 195 above was prepared according to the procedure described in Scheme VI above from 3-(2-hydroxyethoxy)benzaldehyde and 4-dimethylaminobenzoic acid. 1 H NMR (DMSO, 500 MHz) 11.58 (s), 8.39 (s), 7.80 (d), 7.34 (t), 6.98 (d), 6.74 (d), 4.90 (t), 4.02 (t), 3.75-3.69 (m), and 2.99 (s). Example 96 2E-(4-Phenylphenyl)acryl(2-hydroxy-3-methoxybenzylidene)hydrazide (Compound 196) Compound 196 above was prepared according to the procedure described in Scheme VI above from 2-hydroxy-3-methoxybenzaldehyde and 2E-(4-phenylphenyl)acrylic acid. The molecular weight of C 23 H 20 N 2 O 3 is 372.42; m/z (MH + ): calculated 373.15 and observed 373.00. Example 97 2E-(4-Phenylphenyl)acryl(3-(2-hydroxyethoxy)benzylidene)hydrazide (Compound 197) Compound 197 above was prepared according to the procedure described in Scheme VI above from 3-(2-hydroxyethoxy)benzaldehyde and 2E-(4-phenylphenyl)acrylic acid. The molecular weight of C 24 H 22 N 2 O 3 is m/z (MH + ): calculated 387.17 and observed 387.00. Example 98 2E-(4-Phenylphenyl)acryl(4-(2-hydroxyethoxy)benzylidene)hydrazide (Compound 198) Compound 198 above was prepared according to the procedure described in Scheme VI above from 4-(2-hydroxyethoxy)benzaldehyde and 2E-(4-phenylphenyl)acrylic acid. The molecular weight of C 24 H 22 N 2 O 3 is m/z (MH + ): calculated 387.17 and observed 386.88. Example 99 4-(2-Hydroxyethylamino)benz(3-methoxybenzylidene)hydrazide (Compound 199) Compound 199 above was prepared according to the procedure described in Scheme VI above from 3-methoxybenzaldehyde and 4-(2-hydroxyethylamino)benzoic acid. 1 H NMR (500 MHz, CD 3 OD) 8.25 (s, 1H); 7.77 (d, 2H, J=8.8 Hz); 7.56 (s, 1H) 7.33-7.26 (m, 2H); 6.98-6.95 (m, 1H); 6.70-6.68 (m, 2H); 3.85 (s, 3H); 3.73 (t, 2H, J=5.9 Hz); 3.30 (t, 2H, J=5.9 Hz). Example 100 Cell Proliferation Assay The primary testing for the exemplified compounds was performed in UT7/EPO Cell line. UT7/EPO is human leukemia cell line, obtained from Dr. Norio Komatsu ( Blood , Vol 82 (2), pp 456-464, 1993). These cells express endogenous EPO receptor and are dependant upon EPO for growth and proliferation. Briefly, the cells were starved of EPO overnight and plated in 96 or 384 well plates. The compounds were added to the cells at 10 uM concentration. The plates were then incubated at 37° C. for 72 hours. The proliferative effect of the compounds was measured by a commercially available kit from Lonza (ViaLight Plus). The activities of the compounds are listed in the following table. Activity Activity Activity Compound (%) Compound (%) Compound (%) 108 2.4 121 12 123 5.1 124 3.4 125 15 126 3.4 127 6.8 128 5.6 129 23 130 20 131 15 132 8.7 133 14 134 14 135 12 136 4.8 137 12 138 18 139 7.8 140 14 141 17 142 6.0 143 14 144 15 146 4.2 148 7.1 149 9.7 150 4.5 151 6.3 152 6.9 153 5.3 154 6.7 155 11 156 7.9 157 9.9 158 16 159 8.9 160 6.1 161 12 163 23 164 11 165 14 167 11 168 11 170 4.7 171 16 172 9.8 173 12 174 19 175 4.3 176 19 177 9.1 179 4.3 180 3.2 181 4.2 182 11 184 21 185 16 186 9.6 187 17 188 5.5 189 9.1 190 20 191 6.2 192 5.3 193 7.3 194 5.2 195 7.3 196 15 198 4.6 199 3.0 Notes: 1) Activity represents efficacy of a compound tested at 10 uM concentration relative to EPO (100%) in the UT7/EPO proliferation assay.	The present embodiments relate to compounds with physiological effects, such as the activation of hematopoietic growth factor receptors. The present embodiments also relate to use of the compounds to treat a variety of conditions, diseases and ailments such as hematopoietic conditions and disorders.	2
RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 10/141,208, filed May 8, 2002, now abandoned, which claims, as does the present application priority to U.S. provisional application Ser. No. 60/303,292, filed Jul. 6, 2001, the disclosures of all of which are incorporated by reference in their entirety. BACKGROUND OF THE INVENTION The present invention relates to new positive allosteric AMPA receptor modulators, processes for preparing them, and their use as pharmaceutical compositions. Compounds which are structurally similar to the compounds according to the invention are disclosed in WO 99/67242 which describes carbapenem derivatives with an antibacterial activity, wherein naphtho[1,8-de]-2,3-dihydro-1,1-dioxide-1,2-thiazine is used as a synthesis component. SUMMARY OF THE INVENTION The compounds according to the invention are compounds of general formula (I) wherein: R 1 denotes a group selected from among hydrogen, a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, —SO 2 H, —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 6 -alkyl, —CO—C 1 –C 6 -alkyl, —O, phenyl-C 1 –C 4 -alkyl, —C 1 –C 4 -alkyl-NR 6 R 7 , and —C 1 –C 4 -alkyl-O—C 1 –C 4 -alkyl, and C 3 –C 6 -cycloalkyl, R 2 and R 3 , which may be identical or different, denote a group selected from among hydrogen, a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —NO 2 , —SO 2 H, —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 6 -alkyl, —CO—C 1 –C 6 -alkyl, —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, —C 1 –C 4 -alkyl-NR 6 R 7 , and —C 1 –C 1 – 4 -alkyl-O—C 1 –C 4 -alkyl, and C 3 –C 6 -cycloalkyl, or R 1 and R 2 together denote a C 4 –C 6 -alkylene bridge; R 6 and R 7 , which may be identical or different, denote hydrogen, C 1 –C 4 -alkyl, or —CO—C 1 –C 4 -alkyl; R 8 and R 9 , which may be identical or different, denote hydrogen or C 1 –C 4 -alkyl; R 4 , each of which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, phenyl-C 1 –C 4 -alkyl, halogen, —CN, —NO 2 , —SO 2 H, —SO 3 H, —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 1 –C 6 -alkyl, —SO 2 —NR 6 R 7 , —COOH, —CO—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —CO—NR 6 R 7 , —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, —NR 6 R 7 , and an aryl group optionally mono or polysubstituted by halogen atoms, —NO 2 , —SO 2 H, or C 1 –C 4 -alkyl; R 5 , each of which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, phenyl-C 1 –C 4 -alkyl, halogen, —CN, —NO 2 , —SO 2 H, —SO 3 H, —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 6 -alkyl, —SO 2 —NR 6 R 7 , —COOH, —CO—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —CO—NR 6 R 7 , —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, —NR 6 R 7 , and an aryl group optionally mono or polysubstituted by halogen atoms, —NO 2 , —SO 2 H, or C 1 –C 4 -alkyl; and n and m, which may be identical or different, represent 0, 1, 2, or 3, with the proviso that naphtho[1,8-de]-2,3-dihydro-1,1-dioxide-1,2-thiazine is excluded, optionally in the form of their various enantiomers and diastereomers, and the pharmacologically acceptable salts thereof. Preferred compounds are the compounds of general formula (I), wherein: R 1 denotes a group selected from among hydrogen, a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, —SO 2 H, —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 6 -alkyl, —CO—C 1 –C 6 -alkyl, —O, —C 1 –C 4 -alkyl-NR 7 R 8 , and —C 1 –C 4 -alkyl-O—C 1 –C 4 , or benzyl, R 2 and R 3 , which may be identical or different, denote a group selected from among hydrogen, a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —NO 2 , —SO 2 H, —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 6 -alkyl, —CO—C 1 –C 6 -alkyl, —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, —C 1 –C 4 -alkyl-NR 6 R 7 , and —C 1 –C 4 -alkyl-O—C 1 –C 4 -alkyl, or R 1 and R 2 together denote a C 4 –C 6 -alkylene bridge; R 6 and R 7 , which may be identical or different, denote hydrogen, C 1 –C 4 -alkyl, or —CO—C 1 –C 2 -alkyl; and R 4 , each of which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —CN, —NO 2 , —SO 2 H, —SO 3 H, —COOH, —CO—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —CO—NR 6 R 7 , —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, and —NR 6 R 7 ; R 5 , each of which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —CN, —NO 2 , —SO 2 H, —SO 3 H, —COOH, —CO—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —CO—NR 6 R 7 , —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, and —NR 6 R 7 ; and n and m, which may be identical or different, represent 0, 1, or 2, optionally in the form of the various enantiomers and diastereomers thereof, as well as the pharmacologically acceptable salts thereof. Particularly preferred are compounds of general formula (I), wherein: R 1 denotes hydrogen, C 1 –C 4 -alkyl, or benzyl, R 2 and R 3 , which may be identical or different, denote hydrogen or C 1 –C 4 -alkyl, or R 1 and R 2 together denote a butylene bridge; R 4 , each of which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —CN, —NO 2 , —COOH, —CO—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —CO—NR 6 R 7 , —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, and —NR 6 R 7 ; R 5 , each of which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —CN, —NO 2 , —COOH, —CO—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —CO—NR 6 R 7 , —OH, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, and —NR 6 R 7 ; and n and m, which may be identical or different, represent 0, 1, or 2, optionally in the form of the various enantiomers and diastereomers thereof, as well as the pharmacologically acceptable salts thereof. Also particularly preferred are compounds of general formula (I), wherein: R 1 , R 2 , and R 3 , which may be identical or different, denote hydrogen or C 1 –C 4 -alkyl; R 4 , which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —NO 2 , —O—CO—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —O—C 1 –C 6 -alkyl, and —NR 6 R 7 ; R 5 , which may be identical or different, denotes a group selected from among a C 1 –C 6 -alkyl group optionally substituted by one or more halogen atoms, halogen, —NO 2 , —O—CO—C 1 –C 4 -alkyl, —O—CO—O—C 1 –C 4 -alkyl, —O—C 1 –C 6 -alkyl, and —NR 6 R 7 ; and n and m, which may be identical or different, represent 0, 1, or 2, optionally in the form of the various enantiomers and diastereomers thereof, as well as the pharmacologically acceptable salts thereof. Of particular importance according to the invention are the compounds of general formula (I), wherein R 1 denotes methyl, ethyl, isopropyl, n-butyl, or benzyl, optionally in the form of the various enantiomers and diastereomers thereof, as well as the pharmacologically acceptable salts thereof. Particularly preferred are compounds of general formula (I) wherein R 1 denotes methyl, optionally in the form of the pharmacologically acceptable salts thereof. Also particularly preferred are compounds of general formula (I), wherein: R 1 denotes methyl; R 2 and R 3 denote hydrogen; R 4 and R 5 , which may be identical or different, denote halogen, preferably fluorine, chlorine, or bromine, most preferably fluorine or chlorine; and n and m, which may be identical or different, represent 0, 1, or 2, preferably 0 or 1, optionally in the form of the pharmacologically acceptable salts thereof. The alkyl groups used, unless otherwise stated, are branched and unbranched alkyl groups having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. Examples include: methyl, ethyl, propyl, butyl, pentyl, and hexyl. The groups methyl, ethyl, propyl, or butyl may optionally also be referred to by the abbreviations Me, Et, Pr, or Bu. Unless otherwise stated, the definitions propyl, butyl, pentyl, and hexyl also include all possible isomeric forms of the groups in question. Thus, for example, propyl includes n-propyl and isopropyl, butyl includes isobutyl, sec-butyl, and tert-butyl, etc. In the above mentioned alkyl groups, one or more hydrogen atoms may optionally be substituted by the halogen atoms fluorine, chlorine, bromine, or iodine. The substituents fluorine and chlorine are preferred. The substituent fluorine is particularly preferred. If desired, all the hydrogen atoms of the alkyl group may be replaced. The alkyl group mentioned in the group phenyl-C 1 –C 4 -alkyl may be in branched or unbranched form. Unless otherwise stated benzyl and phenylethyl are preferred phenyl-C 1 –C 4 -alkyl groups. Benzyl is particularly preferred. The alkyl groups mentioned in the groups —SO 2 —C 1 –C 6 -alkyl, —SO—C 1 –C 6 -alkyl, —CO—C 1–C 6 -alkyl, —CO—C 1 –C 4 -alkyl, —C 1 –C 4 -alkyl-NR 6 R 7 , —C 1 –C 4 -alkyl-O—C 1 –C 6 -alkyl, —O—C 1 –C 6 -alkyl, —S—C 1 –C 6 -alkyl, —O—CO—C 1 –C 4 -alkyl, —CO—O—C 1 –C 4 -alkyl, or —O—CO—O—C 1 –C 4 -alkyl may be in branched or unbranched form with 1 to 6 carbon atoms, preferably with 1 to 4 carbon atoms, particularly preferably with 1 to 3 carbon atoms, most preferably with 1 to 2 carbon atoms. The C 4 –C 6 -alkylene bridge may, unless otherwise stated, be branched and unbranched alkylene groups having 4 to 6 carbon atoms, for example, n-butylene, 1-methylpropylene, 2-methylpropylene, 1,1-dimethylethylene, 1,2-dimethylethylene, etc. n-Butylene bridges are particularly preferred. The aryl group is an aromatic ring system having 6 to 10 carbon atoms, preferably phenyl. In the above mentioned aryl groups, one or more hydrogen atoms may optionally be substituted by halogen atoms, —NO 2 , —SO 2 H, or —C 1 –C 4 -alkyl, preferably fluorine, chlorine, —NO 2 , ethyl, or methyl, most preferably fluorine or methyl. The term C 3 –C 6 -cycloalkyl denotes saturated cyclic hydrocarbon groups having 3 to 6 carbon atoms, for example, cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl. The term halogen, unless otherwise stated, refers to fluorine, chlorine, bromine, and iodine, preferably fluorine, chlorine, and bromine, most preferably fluorine and chlorine, most preferably fluorine. As already mentioned, the compounds of formula (I) or the various enantiomers and diastereomers thereof may be converted into the salts thereof, particularly, for pharmaceutical use, into the physiologically and pharmacologically acceptable salts thereof. These salts may on the one hand take the form of physiologically and pharmacologically acceptable acid addition salts of the compounds of formula (I) with inorganic or organic acids. On the other hand, the compound of formula (I) where R 1 is hydrogen may be converted by reaction with inorganic bases into physiologically and pharmacologically acceptable salts with alkali or alkaline earth metal cations as counter-ions. The acid addition salts may be prepared, for example, using hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, methanesulfonic acid, acetic acid, fumaric acid, succinic acid, lactic acid, citric acid, tartaric acid, or maleic acid. It is also possible to use mixtures of the above acids. For preparing the alkali and alkaline earth metal salts of the compound of formula (I) wherein R 1 denotes hydrogen, it is preferable to use the alkali and alkaline earth metal hydroxides and hydrides, the hydroxides and hydrides of the alkali metals, especially sodium and potassium, being preferred, while sodium and potassium hydroxide are particularly preferred. DETAILED DESCRIPTION OF THE INVENTION The compounds according to the invention may be prepared in a manner known per se. The following general methods of synthesis 1 and 2 shown in Diagrams 1 and 2 below are meant to illustrate the invention without restricting it to their content. Method 1 Starting from a compound of formula (II), a compound of formula (III) is prepared by sulfonation and subsequent chlorination. The compound of formula (IV) obtained after condensation with aminoacetic acid derivatives is cyclized by adding polyphosphoric acid to the target compound (I). The general preparation of the compounds according to the invention in accordance with Diagram 1 is described in detail hereinafter. Sulfonation of the Naphthalene Derivative (II) About 10 mmol of the naphthalene derivative (II) are taken up in 2 mL to 100 mL, preferably 3 mL to 80 mL, most preferably about 4 mL, of acetic anhydride and 10 mmol to 100 mmol, preferably 11 mmol to 80 mmol, particularly preferably 11 mmol or concentrated sulfuric acid is added at 0° C. to 50° C., preferably 5° C. to 20° C., particularly preferably about 18° C. After 2 hours to 16 hours, preferably about 5 hours, stirring at 20° C. to 100° C., preferably about 25° C., the mixture is poured onto a saturated NaCl solution. The crystals formed are isolated. Methylene chloride, diisopropylether, ethyl acetate, trichloromethane, toluene, benzene, or 1,4-dioxane may be used instead of acetic acid anhydride, while fuming sulfuric acid, sulfur trioxide, chlorine sulfates or combinations thereof may be used as an alternative to concentrated sulfuric acid. Synthesis of the Naphthalene-1-sulfonic Acid Chlorides (III) About 10 mmol of the naphthalene-1-sulfonic acids are combined successively with 10 mmol to 500 mmol, preferably about 90 mmol, of phosphorus oxytrichloride and 8 mmol to 50 mmol, preferably about 10 mmol, of phosphorus pentachloride and heated for 2 hours to 16 hours, preferably about 5 hours, at 20° C. to 100° C., preferably by refluxing. Then the reaction mixture is evaporated down and combined with water. After extraction with organic diluent, the combined organic extracts are dried and freed from solvent. The crude product obtained is used in the subsequent steps without being purified. Instead of the phosphorus oxytrichloride/phosphorus pentachloride mixture, thionyl chloride, phosphorus pentachloride, a phosphoric acid/chlorine mixture, or phosgene may be used. The reaction may alternatively be carried out in the diluents ethyl acetate, water, acetonitrile, N,N-dimethylacetamide, sulfolane, DMF, hexane, or dichloroethane. Synthesis of the Naphthalene-1-sulfonylaminoacetic Acids About 10 mmol of the chlorosulfonylnaphthalenes, 10 mmol to 100 mmol, preferably 11 mmol to 30 mmol, most preferably about 12 mmol, of aminoacetic acid and 10 mmol to 100 mmol, preferably 11 mmol to 30 mmol, most preferably about 12 mmol, of sodium hydroxide are dissolved in water and toluene. The reaction mixture is stirred for 2 hours to 16 hours at 0° C. to 110° C., preferably at about 65° C., then the phases are separated. The aqueous phase is acidified and extracted. The combined organic extracts are dried and evaporated down. Purification may be carried out by chromatography. Triethylamine, potassium carbonate, sodium hydrogen carbonate, or sodium hydride may be used instead of sodium hydroxide, while tetrahydrofuran, diethylether, dichloromethane, trichloromethane, dioxane, acetone, benzene, ethanol, methanol, ethyl acetate, or acetonitrile may be used instead of toluene. Cyclization of the Naphthalene-1-sulfonylaminoacetic Acids (IV) About 10 mmol of the naphthalene-1-sulfonylaminoacetic acids are combined with 10 g to 200 g, preferably about 40 g, of polyphosphoric acid and stirred for 2 hours to 16 hours, preferably about 5 hours, at 20° C. to 110° C., preferably 75° C. to 95° C., most preferably at about 80° C. Then the reaction mixture is poured onto water and extracted. The combined organic extracts are dried and evaporated down. The residue is purified. Method 2 The compounds of formula (III) obtained as intermediate compounds in Method 1 are reacted with primary amines to obtain the compounds of formula (V) and then cyclized by the addition of a compound of formula R 2 R 3 C═O in the presence of strong acid to obtain the target compounds (I). In order to prepare the compounds of formula (I) wherein R 1 and R 2 represent hydrogen, paraformaldehyde, trioxane, or formalin may be used and methanesulfonic acid, trifluoroacetic acid, sulfuric acid, phosphoric acid, or polyphosphoric acid may be used as strong acids. The general preparation of the compounds according to the invention in accordance with Diagram 2 is described in detail hereinafter. Synthesis of the Naphthalenesulfonamides (V) About 10 mmol of the chlorosulfonylnaphthalenes (III) are combined with an alcoholic solution of the primary amine (10 mmol to 1000 mmol in 5 mL to 200 mL, for example, 200 mmol in 50 mL ethanol) and then heated to 0° C. to 100° C. for 2 hours to 16 hours, preferably about 5 hours, preferably by refluxing. Then the reaction mixture is evaporated down and purified. Instead of the alcoholic solvent, it is also possible to use toluene, benzene, trichloromethane, dichloromethane, diethylether, tetrahydrofuran, water, acetonitrile, acetic anhydride, acetone, pyridine, dimethylsulfoxide, dimethylformamide, dioxane, or hexane. Cyclization of the Naphthalene-1-sulfonamides (V) to Form the Target Compounds (I) About 10 mmol of the naphthalene-1-sulfonamides are added to 0 mL to 100 mL, preferably 20 mL to 80 mL, most preferably about 40 mL of methanesulfonic acid and combined with a solution of 3 mmol to 50 mmol, preferably 4 mmol to 30 mmol, most preferably 5 mmol of trioxane in 0 mL to 100 mL, preferably about 12 mL, of trifluoroacetic acid. The reaction mixture is stirred for 2 hours to 16 hours, preferably 5 hours, at 20° C. to 100° C., preferably 30° C. to 80° C., most preferably about 35° C. and then poured onto ice water. After extraction and drying of the combined organic extracts, the solution is evaporated down. The crude product is purified. Instead of trioxane, it is possible to use paraformaldehyde or formalin, while instead of trifluoroacetic acid it is possible to use boron trifluoride-diethylether, acetic acid, polyphosphoric acid, phosphoric acid, or sulfuric acid. Acetic anhydride or dichloromethane may be used as possible diluents. The new compounds of general formula (I) may be synthesized analogously to the following Examples of synthesis. These Examples are, however, intended solely as examples of procedure to illustrate the invention further without restricting it to the subject matter thereof. EXAMPLE 1 Synthesis of 2-methyl-2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide 2.21 g of N-methyl-1-naphthalenesulfonic acid amide is dissolved in 25 mL of methanesulfonic acid at 35° C. and combined with a solution of 0.30 g of trioxane in 8 mL of trifluoroacetic acid. After 2 hours stirring at ambient temperature, the reaction mixture is poured onto 300 mL of ice water. The solid formed is separated off by filtration, washed with 100 mL of water, and dried overnight. After crystallization from methylcyclohexane, the product is isolated as a white solid. Yield: 2.20 g; m.p.: 136° C. EXAMPLE 2 Synthesis of 6-chloro-2-methyl-2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide 0.45 g of 5-chloro-naphthalene-1-sulfonic acid-N-methylamide is dissolved in 6.8 mL of methanesulfonic acid at 35° C. and combined with a solution of 0.07 g of trioxane in 2 mL of trifluoroacetic acid. After 2 hours stirring at 35° C., the reaction mixture is poured onto 100 mL of ice water and the aqueous phase is extracted with ethyl acetate. The organic extracts collected are dried with sodium sulfate, evaporated down in vacuo, and then purified by chromatography. Yield: 0.41 g; m.p.: 150° C. EXAMPLE 3 Synthesis of 2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide Naphthalene-1-sulfonic acid tert-butylamide 8 mL of tert-butylamine is placed in 50 mL of chloroform, cooled to 0° C., and 5.75 g of 1-naphthalenic acid chloride in 45 mL of chloroform are added dropwise. Then the mixture is stirred for 24 hours at ambient temperature. After concentration by evaporation in vacuo, the residue obtained is dissolved in dichloromethane and washed with 2 N hydrochloric acid. The organic extracts collected are dried with sodium sulfate and evaporated down in vacuo. Yield: 5.48 g. 2-tert-butyl-1,1-dioxo-1,2-dihydro-1λ 6 -naphtho[1,8-de][1,3]thiazin-3-one 4.36 g of naphthalene-1-sulfonic acid tert-butylamide is placed in 80 mL tetrahydrofuran, cooled to −10° C., and 29 mL of N-butyl lithium (1.6 molar solution in hexane) are cautiously added dropwise. The mixture is first stirred for 0.5 hour at −10° C., then for 3 hours at ambient temperature. Then it is cooled to −5° C. and within 0.25 hour, CO 2 obtained from dry ice is piped in. The reaction mixture is stirred for 2.5 hours at ambient temperature, then combined with water. The solution is poured onto 4 N hydrochloric acid and extracted with ethyl acetate. The organic extracts collected are dried with sodium sulfate and, after evaporation in vacuo, purified by chromatography. Yield: 0.42 g. 2-tert-butyl-2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide 0.17 g of 2-tert-butyl-1,1-dioxo-1,2-dihydro-1λ 6 -naphtho[1,8-de][1,3]thiazin-3-one is suspended in 2 mL tetrahydrofuran at ambient temperature and 1.17 mL of borane-tetrahydrofuran complex (1 molar solution) is added. Then the mixture is refluxed with stirring for 100 hours, with a total of a further 8.2 mL of 1M borane-tetrahydrofuran complex solution being added in several batches. The reaction mixture is combined with 2 mL of 2 N hydrochloric acid and with 2 mL of methanol, then refluxed for 12 hours with stirring. 2 mL of ammonia is added and any crystals formed are filtered off. The filtrate is extracted with ethyl acetate and the organic extracts collected are dried with sodium sulfate. After evaporation in vacuo, the residue obtained is purified by chromatography. Yield: 0.06 g. 2,3-Dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide 0.06 g of 2-tert-butyl-2,3-dihydro-naphtho[1,8-de][1,3]thiazin-1,1-dioxide is dissolved in 1 mL of dichloromethane and 0.02 mL of trifluoroacetic acid is added. Then the mixture is stirred for a total of 22 hours at reflux temperature and for 96 hours at ambient temperature, while during this period a total of 0.07 mL of trifluoroacetic acid is added. The reaction mixture is evaporated down in vacuo and purified by chromatography. Yield: 0.034 g; m.p.: 206° C.–207° C. EXAMPLE 4 Synthesis of [2-(1,1-dioxo-1H-3H-1λ 6 -naphtho[1,8-de]thiazine-2-yl)ethyl]dimethylamine 0.028 g of sodium hydride is suspended in 0.5 mL of dimethylformamide and 0.073 g of 2,3-dihydro-naphtho[1,8-de][1,3]thiazine-1,1-dioxide in 1 mL of dimethylformamide is added. Then 0.053 g of diethylaminoethyl chloride-hydrochloride are added batchwise. The reaction mixture is stirred for 18 hours at ambient temperature and then poured onto ice water. The mixture is extracted with dichloromethane and the organic extracts collected are dried with sodium sulfate. After evaporation in vacuo, the residue obtained is purified by chromatography. Yield: 0.035 g; m.p.: 97° C.–98° C. EXAMPLE 5 Synthesis of N-(2-methyl-1,1-dioxo-2,3-dihydro-1H-1λ 6 -naphtho[1,8-de][1,3]thiazin-6-yl)-acetamide 5-acetylaminonaphthalene-1-sulfonylchloride 1.40 g of 5-acetylaminonaphthalene-1-sulfonic acid and 2.23 g of phosphorus pentachloride are combined and stirred for 4 hours at 60° C. Then the solution is poured onto ice water and extracted with dichloromethane. The organic extracts collected are dried with sodium sulfate and evaporated down in vacuo. Yield: 1.10 g. N-(5-methylsulfamoylnaphthalene-1-yl)-acetamide 1.10 g of 5-acetylaminonaphthalene-1-sulfonyl chloride is dissolved in 8 mL of ethanol and 8 mL of methylamine solution in ethanol are added dropwise. Then the resulting mixture is stirred at reflux temperature for 3.5 hours and the solvent is distilled off in vacuo. The residue is purified by chromatography. Yield: 0.50 g. N-(2-methyl-1,1-dioxo-2,3-dihydro-1H-1λ 6 -naphtho[1,8-de][1,3]thiazin-6-yl)-acetamide 0.25 g of N-(5-methylsulfamoylnaphthalene-1-yl)-acetamide is dissolved in 3.4 mL of methanesulfonic acid at 35° C. and combined with a solution of 0.027 g of trioxane in 1 mL of trifluoroacetic acid. After 6 hours stirring at 35° C., the reaction mixture is poured onto ice water and the aqueous phase extracted with ethyl acetate. The organic extracts collected are dried with sodium sulfate, evaporated down in vacuo, and purified by chromatography. Yield: 0.136 g; m.p.: 189° C.–190° C. EXAMPLE 6 Synthesis of 2-(1,1-Dioxo-1H,3H-1λ 6 -naphtho[1,8-de][1,3]thiazin-2-yl)-acetamide 8-tert-butylsulfamoylnaphthalene-1-carboxylic acid 4.36 g of naphthalene-1-sulfonic acid tert-butylamide are placed in 80 mL tetrahydrofuran, cooled to −10° C., and 29 mL of N-butyl lithium (1.6 molar solution in hexane) are cautiously added dropwise. The mixture is stirred first for 0.5 hour at −10° C., then for 3 hours at ambient temperature. It is then cooled to −5° C. and CO 2 obtained from dry ice is piped in within 0.25 hour. The reaction mixture is stirred for 2.5 hours at ambient temperature and then combined with water. The solution is poured onto 4 N hydrochloric acid and extracted with ethyl acetate. The organic extracts collected are dried with sodium sulfate and, after evaporation in vacuo, purified by chromatography. Yield: 1.19 g. 1,1-Dioxo-1,1-dihydro-1λ 6 -naphtho[1,8-de][1,3]thiazin-3-one 0.25 g of polyphosphoric acid and 0.15 g of 8-tert-butylsulfamoylnaphthalene-1-carboxylic acid are combined. The mixture is stirred for 4 hours at 150° C. Then the reaction mixture is poured onto ice water and the aqueous phase is extracted with ethyl acetate. The organic extracts collected are dried with sodium sulfate and evaporated down in vacuo. Yield: 0.07 g. 2,3-Dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide 0.07 g of 1,1-dioxo-1,1-dihydro-1λ 6 -naphtho[1,8-de][1,3]thiazin-3-one is dissolved in 2 mL of tetrahydrofuran and then 1.2 mL of 1 molar borane-tetrahydrofuran complex solution is carefully added dropwise. The mixture is stirred for 18 hours at reflux temperature. The reaction mixture is combined with 1.5 mL of 2 N hydrochloric acid and 2 mL of methanol, then stirred for 2 hours at reflux temperature. 2 mL of ammonia is added and any crystals formed are filtered off. The filtrate is extracted with ethyl acetate, the organic extracts collected are dried with sodium sulfate and evaporated down in vacuo. Yield: 0.06 g. 2-(1,1-Dioxo-1H,3H-1λ 6 -naphtho[1,8-de][1,3]thiazin-2-yl)-acetamide 0.011 g of sodium hydride is suspended in 0.5 mL of dimethylformamide, and 0.06 g of 2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide in 1 mL of dimethylformamide is added. The mixture is stirred for 1 hour at ambient temperature and then 0.042 g of 2-bromoacetamide are added batchwise. Then the mixture is stirred for 18 hours at ambient temperature. The reaction mixture is poured onto ice water and extracted with dichloromethane. The organic extracts collected are dried with sodium sulfate and, after evaporation in vacuo, purified by chromatography. Yield: 0.043 g; m.p.: 195° C.–196° C. EXAMPLE 7 Synthesis of 7-hydroxy-2-methyl-2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide 0.6 g of 7-methoxy-2-methyl-2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide is dissolved in 23 mL dichloromethane and the solution is cooled to −78° C. 2.3 mL of boron tribromide (1 molar solution in dichloromethane) is added dropwise. Then the mixture is stirred for 24 hours at ambient temperature. After evaporation in vacuo, the residue is purified by chromatography. Yield: 0.36 g; m.p.: 245° C.–246° C. EXAMPLE 8 Synthesis of methyl 2-methyl-1,1-dioxo-2,3-dihydro-1H-1,6-naphtho[1,8-de][1,3]thiazin-7-yl ester carboxylate 0.11 g of 7-hydroxy-2-methyl-2,3-dihydronaphtho[1,8-de][1,3]thiazine-1,1-dioxide and 0.061 mL triethylamine are placed in 2 mL toluene and cooled to 0° C. 0.037 mL of methyl chloroformate are added dropwise. Then the mixture is stirred for 5 hours at ambient temperature. The suspension is then poured onto ice water and extracted with ethyl acetate. The organic extracts collected are dried with sodium sulfate and, after evaporation in vacuo, purified by chromatography. Yield: 0.065 g; m.p.: 161° C.–162° C. The following compounds of formula (IA) are obtained, inter alia, analogously to the procedure described hereinbefore: TABLE 1 (IA) Example R 1 R 2 R 3 R 4 R 5 R 6 m.p. (° C.) 9 CH 3 H H H H Br 226–227 10 CH 3 NO 2 H H H H 264–265 11 CH 3 H H OCH 3 H H 174–175 12 CH 3 H H F H H 129–130 13 CH 3 H H Br H H 163–164 14 CH 3 H H CH 3 H H 142–143 15 CH 3 H H I H H 192–193 16 CH 3 H I H H H 160–161 17 CH 3 H NO 2 H H H 169–170 18 CH 3 H OH H H H 160–161 19 CH 3 N(CH 3 ) 2 H H H H 20 CH 3 H H H H N(CH 3 ) 2 21 CH 3 i-Pr H H i-Pr H 22 CH 3 H OCOMe H H H 23 CH 3 H F H H H It has been found that the compounds of general formula (1) are characterized by their wide range of applications in the therapeutic field. Particular mention should be made of those applications in which the positive modulation of AMPA receptors plays a part. The effect of the compounds according to the invention as AMPA receptor modulators was measured electrophysiologically on cells which express functional AMPA receptors. Investigations were carried out to see whether the test substances have a positive allosteric influence on the agonist-induced current. The test was carried out at concentrations of between 0.3 μmol and 300 μmol. TABLE 2 Intensification of the Agonist-Induced Current Example Activity 1 + 2 + + Legend: + good; + + very good The new compounds can also be used to treat illnesses or conditions in which neuronal networks which require AMPA receptors in order to function are damaged or limited in their function. The compounds of general formula (I) can thus be used in dementias, in neurodegenerative or psychotic illnesses and in neurodegenerative disorders and cerebral ischemias of various origins, preferably in schizophrenia or learning and memory disorders. The following are also included: epilepsy, hypoglycemia, hypoxia, anoxia, cerebral trauma, brain edema, amyotrophic lateral sclerosis, Huntington's Disease, Alzheimer's disease, sexual dysfunction, disorders of sensory/motor function, memory formation, hyperkinetic behavioral changes (particularly in children), hypotension, cardiac infarct, cerebral pressure (increased intracranial pressure), ischemic and hemorrhagic stroke, global cerebral ischaemia on stoppage of the heart, acute and chronic neuropathic pain, diabetic polyneuropathy, tinnitus, perinatal asphyxia, psychosis, Parkinson's disease and depression, and related anxiety states. The new compounds may also be given in conjunction with other active substances, such as those used for the same indications or, for example, with neuroleptics, nootropics, psychostimulants, etc. They may be administered topically, orally, transdermally, nasally, parenterally, or by inhalation. Moreover, the compounds of general formula (I) or the salts thereof may also be combined with active substances of other kinds. The compounds of general formula (I) may be given on their own or in conjunction with other active substances according to the invention, and possibly also in conjunction with other pharmacologically active substances. Suitable preparations include, for example, tablets, capsules, suppositories, solutions (particularly solutions for injection (s.c., i.v., and i.m.) and infusion), elixirs, emulsions, or dispersible powders. The content of the pharmaceutically active compound(s) should be in the range from 0.1 wt. % to 90 wt. %, preferably 0.5 wt. % to 50 wt. % of the composition as a whole, i.e., in amounts which are sufficient to achieve the dosage range specified below. Suitable tablets may be obtained, for example, by mixing the active substance(s) with known excipients, for example, inert diluents such as calcium carbonate, calcium phosphate, or lactose, disintegrants such as corn starch or alginic acid, binders such as starch or gelatine, lubricants such as magnesium stearate or talc, and/or agents for delaying release, such as carboxymethyl cellulose, cellulose acetate phthalate, or polyvinyl acetate. The tablets may also comprise several layers. Coated tablets may be prepared accordingly by coating cores produced analogously to the tablets with substances normally used for tablet coatings, for example, collidone or shellac, gum arabic, talc, titanium dioxide, or sugar. To achieve delayed release or prevent incompatibilities the core may also consist of a number of layers. Similarly the tablet coating may consist of a number of layers to achieve delayed release, possibly using the excipients mentioned above for the tablets. Syrups or elixirs containing the active substances or combinations thereof according to the invention may additionally contain a sweetener such as saccharine, cyclamate, glycerol or sugar and a flavor enhancer, e.g., a flavoring such as vanillin or orange extract. They may also contain suspension adjuvants or thickeners such as sodium carboxymethyl cellulose, wetting agents such as, for example, condensation products of fatty alcohols with ethylene oxide, or preservatives such as p-hydroxybenzoates. Solutions for injection and infusion are prepared in the usual way, e.g., with the addition of isotonic agents, preservatives such as p-hydroxybenzoates, or stabilizers such as alkali metal salts of ethylenediamine tetraacetic acid, optionally using emulsifiers and/or dispersants, whilst if water is used as the diluent, for example, organic solvents may optionally be used as solvating agents or dissolving aids, and transferred into injection vials or ampoules or infusion bottles. Capsules containing one or more active substances or combinations of active substances may for example be prepared by mixing the active substances with inert carriers such as lactose or sorbitol and packing them into gelatine capsules. Suitable suppositories may be made for example by mixing with carriers provided for this purpose, such as neutral fats or polyethyleneglycol or the derivatives thereof. Excipients which may be used include, for example, water, pharmaceutically acceptable organic solvents such as paraffins (e.g., petroleum fractions), vegetable oils (e.g., groundnut or sesame oil), mono- or polyfunctional alcohols (e.g., ethanol or glycerol), carriers such as e.g., natural mineral powders (e.g., kaolins, clays, talc, chalk), synthetic mineral powders (e.g., highly dispersed silicic acid and silicates), sugars (e.g., cane sugar, lactose, and glucose) emulsifiers (e.g., lignin, spent sulfate liquors, methylcellulose, starch, and polyvinylpyrrolidone) and lubricants (e.g., magnesium stearate, talc, stearic acid, and sodium lauryl sulfate). The preparations are administered by the usual methods, preferably by oral or transdermal route, particularly orally. For oral administration, the tablets may of course contain, apart from the above mentioned carriers, additives such as sodium citrate, calcium carbonate, and dicalcium phosphate together with various additives such as starch, preferably potato starch, gelatine, and the like. Moreover, lubricants such as magnesium stearate, sodium lauryl sulfate, and talc may be used at the same time for the tabletting process. In the case of aqueous suspensions, the active substances may be combined with various flavor enhancers or colorings in addition to the excipients mentioned above. For parenteral use, solutions of the active substances with suitable liquid carriers may be used. The dosage for intravenous use is from 1 mg to 1000 mg per hour, preferably between 5 mg and 500 mg per hour. However, it may sometimes be necessary to depart from the amounts specified, depending on the body weight, the route of administration, the individual response to the drug, the nature of its formulation, and the time or interval over which the drug is administered. Thus, in some cases, it may be sufficient to use less than the minimum dose given above, whereas in other cases, the upper limit may have to be exceeded. When administering large amounts, it may be advisable to divide them up into a number of smaller doses spread over the day. The following examples of formulations illustrate the present invention without restricting its scope: Examples of Pharmaceutical Formulations Tablets per Tablet active substance 100 mg lactose 140 mg maize starch 240 mg polyvinylpyrrolidone 15 mg magnesium stearate 5 mg 500 mg The finely-ground active substance, lactose and some of the maize starch are mixed together. The mixture is screened, then moistened with a solution of polyvinylpyrrolidone in water, kneaded, wet-granulated and dried. The granules, the remaining maize starch and the magnesium stearate are screened and mixed together. The mixture is compressed to produce tablets of suitable shape and size. Tablets per Tablet active substance 80 mg lactose 55 mg maize starch 190 mg microcrystalline cellulose 35 mg polyvinylpyrrolidone 15 mg sodium-carboxymethyl starch 23 mg magnesium stearate 2 mg 400 mg The finely ground active substance, some of the corn starch, lactose, microcrystalline cellulose, and polyvinylpyrrolidone are mixed together, the mixture is screened and worked with the remaining corn starch and water to form a granulate which is dried and screened. The sodium carboxymethyl starch and the magnesium stearate are added and mixed in and the mixture is compressed to form tablets of a suitable size. Ampoule Solution active substance 50 mg sodium chloride 50 mg aqua for inj. 5 mL The active substance is dissolved in water at its own pH or optionally at pH 5.5 to 6.5 and sodium chloride is added to make it isotonic. The solution obtained is filtered free from pyrogens and the filtrate is transferred under aseptic conditions into ampoules which are then sterilized and sealed by fusion. The ampoules contain 5 mg, 25 mg, and 50 mg of active substance.	Compounds of formula (I) wherein R 1 , R 2 , R 3 , R 4 , R 5 , n, and m, are as defined herein, or an enantiomer or diastereomer thereof, or a pharmacologically acceptable salt thereof, processes for preparing these compounds, and their use in pharmaceutical compositions.	2
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focusing apparatus comprising a camera having a distance measuring function through a TTL optical system, and a lens with a lens driving circuit for driving the lens in accordance with lens drive amount data supplied from the camera. 2. Description of the Prior Art In a system of the type described above, the distance measurement data obtained during the lens drive operation does not accurately represent an actual distance. Therefore, the distance measuring operation must be prohibited during the lens drive operation. For this purpose, connecting terminals or contacts between the camera and the lens in this system must include a data line for transferring the lens drive amount data to the lens side, and another line for transferring to the camera a signal which represents that the lens is being driven and which is used to disable the distance measuring operation during the lens drive operation. When the lens drive amount data is transferred in the form of a digital signal a data line having a large number of bits is required. For this reason, serial data transfer is adopted. However, in this case, sync clocks for serial data transfer must be supplied from the camera to the lens in addition to the lens drive amount data. This means that a minimum of three lines must be included, resulting in an increase in the number of contacts between the lens and the camera. Various types of lenses can be used, including a lens having a distance measuring function, an AF lens or a normal lens in addition to the lens of the type described above. The camera must allow the mounting of any lens. The AF lens performs automatic focusing. When this lens is mounted on the camera, the camera need not perform an operation to calculate a lens drive amount. With a normal lens, even if a signal representing the lens drive amount is supplied from the camera, the lens cannot be driven. Then, the operation as described above need not be performed. SUMMARY OF THE INVENTION It is an object of the present invention to transfer to a camera a signal representing that a lens is being driven through a line for transmitting sync clocks, so that a single signal line can serve to transmit multiple signals, and the number of terminals between the camera and the lens can be reduced. In order to achieve the above object of the present invention, in an automatic focusing apparatus wherein a lens drive amount is calculated by a distance measuring operation, a signal representing the calculated lens drive amount is supplied to a lens so as to drive the lens, and a lens drive status-signal (signal representing that the lens is being driven) is supplied to the camera so as to prohibit the distance measuring operation during the lens drive operation, wherein there are provided at the camera side an operation circuit for operating or calculating a digital signal representing the lens drive amount based on a distance measuring circuit output, a data terminal for serially transmitting the digital signal from said operation circuit, and a clock terminal for transmitting clock pulses for performing serial transfer of the digital signal; and there is provided at the lens side a signal formation circuit which enables the lens drive status signal to be supplied to said clock terminal after it has detected that the digital signal supplied through said data terminal has been transmitted, and which disables the lens drive status signal upon detecting that the lens drive operation based on the digital signal has been completed. It is another object of the present invention to switch an operation/display mode of a camera in accordance with a type of lens mounted thereon and to set the camera in a mode most suitable for the type of lens mounted. It is still another object of the present invention to use a data terminal for transferring other data (data other than that representing the lens type) and for transmitting data representing the type of lens mounted, so that the total number of data terminals required is reduced. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic view for explaining the distance measuring principle which is adopted in an automatic focusing apparatus of the present invention, and FIGS. 1B and 1C are views for explaining the principle shown in FIG. 1A; FIG. 2 is a block diagram showing an automatic focusing apparatus according to an embodiment of the present invention; FIG. 3 is a circuit diagram showing the main part in the apparatus shown in FIG. 2; FIGS. 4(a) and 4(b) are flow charts for explaining the operation of the circuit shown in FIG. 3; FIG. 5 is a waveform chart for explaining the operation of the circuit shown in FIG. 3; and FIGS. 6A and 6B show circuit diagrams of connecting terminal portions in the case wherein a lens which has not been specifically designed for the camera shown in FIG. 3 is mounted thereon. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An automatic focusing apparatus according to the present invention will now be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing an example of a distance measuring system which is adopted in a camera using a transmission apparatus according to the present invention. Referring to FIG. 1, an image of an object 1 to be photographed is formed on a film surface 3 through a photographic lens 2. A secondary image is formed on two line sensors CR and CF comprising CCDs through a secondary optical system 4. The sensor CR is a reference sensor section which consists of four sensing portions A 0 to A 3 as shown in FIG. B. The sensor CF comprises a sensor section consisting of 18 sensing portions B 0 to B 10 and B -1 to B -7 . The image of the object if formed at a predetermined position on the sensor CF having this arrangement. In the case of the near-focus state, the image is formed at the side of the sensing portions B 2 to B 10 as indicated by 5 (FIGS. 1B and 1C). On the other hand, in the far-focus state, the image is formed at the side of the sensing portions B -1 to B -7 as indicated by 7 in FIGS. 1B and 1C. In the in-focus state, the image is formed on the sensing portions B 0 to B 3 as indicated by 6 in FIGS. 1B and 1C. When the image position on the sensor CF is detected, the focusing state (near- or far-focus state or lens driving direction) and the deviation (distance) from the in-focus position can be detected The distance detection system described above is known. However, the present invention is not limited to a distance detection operation per se and the distance detection operation can be performed by any suitable method available in the present invention. For this reason, an explanation of the distance detection system is confined to the above. FIG. 2 is a block diagram of an embodiment of a camera and a lens in which a transmission apparatus according to the present invention is adopted. The overall apparatus consists of a camera side I and a lens side II. A photosensor section CCDP at the camera side I has the sensors CR and CF described above and an average sensor AC for detecting the average amount of the light which is incident on the sensors CR and CF. The photosensor section CCDP is driven in a known manner by a clock driver CDR which generates two-phase clocks φ1 and φ2 and set clocks φR with reference to clocks from a clock generator CG1. A capacitor C1 is charged by an output from the sensor AC. A comparator CP1 compares the charge on the capacitor Cl with a reference voltage VCP and generates a comparison output (high level; to be referred to as H level hereinafter) when the output from the capacitor C1 exceeds the voltage VCP. A one-shot multivibrator ON1 produces transfer pulses φT in response to the comparison output from the comparator CP1. When the pulse φT is supplied to the photosensor CCDP, photocharges accumulated on the sensing portions of the sensors CR and CF are transferred to analog shift registers of the sensors and are accumulated. The photocharges stored on the analog shift registers are time-serially output in response to the pulses φ1 and φ2. An A/D converter AD receives and converts the time-serial output from the photosensor CCDP into 4-bit digital signals. A central processing unit CPU performs operation processing (to be described later) and sequence control of various other operations of the overall apparatus. A reset terminal RES of the CPU is connected to a switch SW1 which is turned on upon the first stroke of a shutter release button. A signal of H level is normally supplied to the reset terminal RES, so that the program counter of the CPU is set to zero and the start step (to be described later) is designated. When a signal of low level (to be referred to as L level hereinafter) is supplied to the reset terminal RES, the program to be described later is executed from the start block. The CPU also has a terminal NO. When a signal at the terminal NO is enabled (H level), the integration clear gates of the sensors are opened to clear the accumulated charges thereon, a transistor TR is turned on, and the capacitor C1 is reset. When the signal at the terminal NO is disabled (L level), the transistor TR is turned off to start charging the capacitor C1 and to start the accumulation operation of the photocharges by the sensors. Input terminals D0 to D3 are connected to output terminals of the A/D converter AD and receive therefrom digital signals corresponding to the accumulated charges on the sensors. Output ports PA0 to PA5 of the CPU produce operation (calculation) values obtained in a manner to be described later. Input ports PB0 to PB7 of the CPU receive various input data. A terminal PC is used to produce focusing state data such as a lens drive direction or the like. A signal transmission circuit CMC is connected to the input and output ports PA0 to PA5 and PB0 to PB7 of the CPU and a lens drive circuit LP at the lens side. The lens drive circuit LP at the lens side II drives a motor M in accordance with a distance signal and a direction signal. A distance ring of the lens is driven in synchronism with the motor M, and automatic focusing is performed in accordance with the distance signal. FIG. 3 is a circuit diagram showing an embodiment of the signal transmission circuit CMC and the lens drive circuit LP. In the signal transmission circuit CMC shown in FIG. 3, a binary counter CNT1 counts the leading edges or positive-going edges of the clock signal from a clock generator CG2. An output terminal Q3 of the binary counter CNT1 is connected to one input terminal of an OR gate G3 and to an enable terminal ENABLE of the binary counter CNT1. The other input terminal of the OR gate G3 is connected to the clock generator CG2. The OR gate G3 keeps generating clock pulses of the clock generator CG2 until a signal of H level is received, and thereafter generates signals of H level. The pulses from the OR gate G3 are supplied to the lens drive circuit LP through an open-collector buffer G4 and a connecting terminal connecting the lens and camera. Control terminals A and B of a data selector DS1 are connected to output terminals Q1 and Q2 of the binary counter CNT1. When both the control terminals A and B are at L level, the data selector DS1 produces a signal received at an input terminal D0 from an output terminal Y. When the control terminal A is at H level and the control terminal B is at L level, the data selector DS1 produces data received at an input terminal D1 from the output terminal Y. When the control terminal A is at L level and the control terminal B is at H level, the data selector DS1 produces data received at an input terminal D2 from the output terminal Y. When both the control terminals A and B are at H level, the data selector DS1 produces data received at an input terminal D3 from the output terminal Y. As described above, the counter CNT1 is a binary counter. Therefore, the data from the output ports PA0 to PA3 of the CPU are transmitted in synchronism with the clocks in the order of the ports PA0 to PA3. The output ports PA0 to PA2 produce signals representing the amount of lens drive required to attain the in-focus position. The output port PA3 produces a signal representing a drive direction. Input terminals of an AND gate G5 are connected to the output Q3 of the counter CNT1 and the buffer G4 through an inverter G6. An output from the AND gate G5 is connected to an input port PB7 of the CPU. The gate G5 supplies a lens drive status signal (to be referred to as a BUSY signal hereinafter) to the input port PB7. A shift register SH1 receives and shifts serial data (zoom ratio data and lens type data) received from a terminal DATAIN in synchronism with the positive-going edge of the pulse from the OR gate G3. Outputs Q0 to Q3 of the register SH1 are connected to the input ports PB0 to PB3 of the CPU for receiving the zoom ratio data. Input terminals of an AND gate G2 are connected to the output terminals Q0 to Q3 of the register SH1. The AND gate G2 detects if the lens mounted on the camera is a normal manual lens. Input terminals of a NOR gate G1 are also connected to the output terminals Q0 to Q3 of the register SH1. The NOR gate G1 detects if the lens mounted on the camera is a lens which includes a distance measuring circuit and if it has automatic focusing. A binary counter CNT2 of the lens drive circuit LP counts the positive-going edges of the clocks supplied through the buffer G4. Output terminals Q1 and Q2 of the counter CNT2 are connected to input terminals A and B of a data selector DS2. As in the case of the data selector DS1, the data selector DS2 produces signals supplied to the input terminals D0 to D3 from an output terminal Y in synchronism with its counting operation and in the order of the terminals D0 to D3. A zoom plate ZP comprises a conductor which is displaced in accordance with a change in a preset zoom ratio and which contacts with the input terminals D0 and D1 of the data selector DS2 at predetermined positions ZM1 to ZM3. The zoom ratio data is supplied in accordance with data from the zoom plate, and the lens drive amount is compensated in accordance with the zoom ratio data. An output terminal Q3 of the counter CNT2 is connected to an inverting open-collector gate G10. The output terminal of the gate G10 is connected to a clock input terminal CLK of the counter CNT2. A shift register SH2 is connected to the output terminal Y of the data selector DS1 through a data output line DATAOUT. A clock terminal CLK of the shift register SH2 is connected to the buffer G4 through a line CLOCK. The shift register SH2 shifts the input data in synchronism with the positive-going edges of the clocks supplied through the buffer G4. A terminal G of the shift register SH2 is a control terminal for prohibiting the shift operation upon reception of a signal of H level. A latch circuit LT1 comprising a D flip-flop latches a drive direction signal. A clock terminal CK of the latch circuit LT1 is connected to the output terminal Q3 of the counter CNT2. When a signal of H level is received from the terminal Q3 of the counter CNT2, the latch circuit LT1 latches an output signal from the output terminal Q3 of the shift register SH2. An operational amplifier OP1 amplifies an output from the latch circuit LT1. An amplified signal from the operational amplifier OP1 is supplied to a forward/reverse control circuit MD and drives the motor M in the forward or reverse direction in accordance with the direction signal latched in the latch circuit LT1. Input terminals D0 to D2 of a down counter DEC1 are connected to output terminals Q0 to Q2 of the shift register SH2. The down counter DEC1 loads an input signal in response to a positive-going edge of the clocks supplied to a terminal LOAD and counts down in accordance with input clocks supplied to a clock terminal CLK. When the count of the counter DEC1 becomes zero, a signal of H level is produced from a terminal DT≦0. The terminal DT≦0 is connected through an inverter G8 to one input terminal of an AND gate G9 having the other input terminal connected to the output terminal Q3 of the counter CNT2. When the output from the gate G9 is H level, a switch SWm is turned on. A slider BR is slid on a contact plate FP in synchronism with the motor M. A number of pulses corresponding to the drive amount of the motor are generated by the ON/OFF operation of the plate FP and the slider BR. Automatic focusing in the camera and lens system of the present invention will be described with reference to the flow chart shown in FIGS. 4(a) and 4(b) and the waveform chart shown in FIG. 5. Assume that power is supplied to the camera and the lens, and the shutter release button is depressed by one stroke. The CPU starts executing the program from START. Note that when the input signal at the terminal RES is at H level, the program counter is reset to zero and the program step is held at the START step. When the first stroke is performed as described above, a switch SW1 is turned on. Since the input at the terminal RES of the CPU goes to L level, holding of the program flow at the START step is released, and the flow advances to the next step PUC . In the step PUC , a negative pulse is supplied from the output port PA5 to the lens drive circuit LP through a terminal PUC at a contact of a mount, thereby initializing the lens drive circuit LP. Then, the counter CNT2 is initially set. Thereafter, the CPU advances to the next dummy communication data set step. In this step, the CPU produces L level signals from all the output ports PA0 to PA3. Data SIGN produced from the port PA3 represents the drive direction of the lens. DATA VAL0 to VAL2 from the ports PA0 to PA2 represent the drive amount. When these data are set, the flow advances to the communication routine call step. In this step, a communication routine (to be described later) is read out, and the data at the lens side is read without driving the lens in accordance with the dummy communication data. In the communication routine, the output port PA4 of the CPU produces a clear pulse CLR (FIG. 5) to reset the counter CNT1. Then, the input to the terminal ENABLE of the counter CNT1 goes to L level. Therefore, the counter CNT1 counts pulses from the clock pulse generator CG2 and changes the levels at the output terminals Q1 to Q3 as shown in FIG. 5. The output terminals Q1 and Q2 of the counter CNT1 are connected to the input terminals A and B of the data selector DS1. The data selector DS1 time-serially produces the data received from the output ports PA0 to PA3 of the CPU from the output terminal Y in accordance with a change (binary change) in the output terminals Q1 and Q2 of the counter CNT1. Clock pulses from the clock pulse generator CG2 are supplied to the shift register SH1 through the gate G3 and to the counter CN2 and the shift register SH2 through the open-collector buffer G4 and the mount contact. The data time-serially produced from the output ports PA0 to PA3 of the CPU are transferred to the shift register SH2 through the data selector DS1. When the counter CNT2 counts, the data selector DS2 time-serially produces the data received at the input terminals D0 to D3 from the output terminal Y. The data produced by the data selector DS2 is transferred to the shift register SH1 through the line DATAIN, thus completing transfer of the data applied to the input terminals of the data selector DS1 to the shift register SH1. During the data transfer as described above, when a signal of H level is produced from the output terminal Q3 of the counter CNT1, this signal is supplied to the terminal ENABLE of the counter CNT1. Therefore, the counter CNT1 stops the counting operation when the above-mentioned data transfer is completed (time J4 in FIG. 5). An output signal EOC from the output terminal Q3 of the counter CNT1 is supplied to the input port PB6 of the CPU, and the CPU fetches the input data received at the input terminals PB0 to PB5. When data transfer is completed in this manner, the output from the output terminal Q3 of the counter CNT2 is at H level as shown in FIG. 5. Therefore, the output from the inverting open-collector gate G10 is also set at L level. Then, one input signal to the AND gate G5 received through the inverter G6 goes to H level. Since the other input to the AND gate G5 is connected to the output terminal Q3 of the counter CNT1, the AND gate G5 produces a BUSY signal of H level representing that the motor is being driven. The BUSY signal is supplied to the input port PB7 of the CPU. When the output terminal Q3 of the counter CNT2 goes to H level, the latch circuit LT1 latches the data from the output terminal Q3 of the shift register SH2. Since the output Q3 from the counter CNT2 is also supplied to the terminal LOAD of the counter DEC1, the counter DEC1 is set in the load mode and sets the data received from the output terminals Q0 to Q2 of the shift register SH2. Since the data produced from the output ports PA0 to PA3 of the CPU in the dummy communication data set step is at L level, the data transferred to the shift register SH2 by the above-mentioned data transfer is all L level. Therefore, data of L level is also loaded in the counter DEC1. When the count is equal to or less than 0, the counter produces a signal of H level from the terminal DT≦0. Then, the output from the inverter G8 goes to L level, and the gate G9 also produces a signal of L level. The switch SWm is kept OFF, and the motor driver MD is kept deactivated. The one-shot multivibrator ON2 is triggered in response to the signal of H level from the terminal DT≦0 of the counter DEC1 and thereupon generates a negative pulse. The negative pulse from the one-shot multivibrator ON2 is supplied to a terminal CLR of the counter CNT2 and the counter CNT2 is then reset. When the counter CNT2 is reset, a signal of L level is produced from the output terminal Q3, the contact CLOCK is set at H level, and the signal of L level is supplied to the AND gate G5 through the inverter G6. The AND gate G5 produces a signal of L level to disable the BUSY signal. In this manner, in the communication routine after the dummy communication data set step, the data at the input ports PB0 to PB5 is fetched in the CPU. Thereafter, the flow advances to the return step, the communication routine ends, and the flow then advances to the next step of turn off indication of direction. In this step, a prohibition signal for prohibiting the operation of a display DISP is produced from a port PC of the CPU to disable the display DISP. Thereafter, the flow advances to the BUSY step. In this step, it is checked if the input to the input port PB7 of the CPU is at H level. As long as the input at the input port PB7 is at H level, the flow keeps returning to the BUSY step. When the input at the port PB7 goes to L level, the flow advances to the next step. At this time, the BUSY signal is at L level, and the flow immediately advances to the accumulation clear step. In this step, a signal of H level is received from the port NO of the CPU to open the integration clear gate of the photosensor CCDP, to clear the accumulation charges on the sensors CR and CF, to turn on the transistor TR and to clear the charge on the capacitor C1. Thereafter, the flow advances to the start charge accumulation step. In this step, the signal from the port NO of the CPU is set at L level so as to start accumulating charges on the sensors CR and CF and to turn off the transistor TR. Then, the respective sensors CR and CF accumulate image signals in accordance with the image state, and the capacitor C1 is charged by the output from the sensor AC which measures the average amount of light incident on the respective sensors. During this step of accumulating the image signals on the sensors, when the charge level on the capacitor C1 exceeds the reference level VCP, the comparator CP1 produces a signal of H level, in response to which the one-shot multivibrator ON1 is turned on. A pulse from the one-shot multivibrator ON1 is supplied to the port CO of the CPU. When the CPU senses this pulse, it advances to the next store data step. The pulse from the one-shot multivibrator ON1 is supplied to the photosensor CCDP as a transfer pulse. In response to this pulse, the photosensor CCDP transfers the photocharges on the sensors CR and CF to the analog shift registers of the sensors and time-serially produces the charges on the sensors CR and CF in response to the pulses φ1 and φ2. When the flow advances to the store data step in the manner as described above, the CPU sequentially stores the input data received at the data ports D0 to D3 in the internal memory. As has been described above, the photosensor sequentially produces the photocharges which are accumulated on the respective sensing portions A 0 to A 3 and B 10 to B -7 . These photocharges are supplied to the A/D converter AD. Therefore, in the store data step, the digital signals from the A/D converter AD which correspond to the photosignals from the sensing portions are time-serially supplied to the data ports D0 to D3 and are sequentially stored in the internal memory. After the data store step is completed in this manner, the flow advances to the direction detection operation step. In this step, the individual data (digital signals corresponding to the photocharges) of the sensing portions B -7 to A 3 of the photosensor CCDP which are stored in the internal memory are used to perform an automatic focusing direction detection operation. This operation is performed in accordance with the detection system described with reference to FIG. 1 and the following term is calculated. ##EQU1## where the digital signals of the charges of the sensing portions A 3 to B -7 are represented by A 3 to B -7 The sign (positive or negative) of the value of the term (1) given above indicates the direction (near- or far-focus) from the in-focus position. Thus, the direction to the in-focus position is calculated. Since this operation itself is not directly related to the present invention, it will not be described. Thereafter, the flow advances to step FEXT. In this step, the data supplied to the input port PB4 of the CPU in the communication routine described above is detected so as to determine if the lens mounted on the camera is an automatic focusing lens having a distance measuring function. In the automatic focusing camera used in the present invention, as shown in FIG. 6A, contacts corresponding to the contacts PUC, CLOCK and DATAOUT of the camera are open, and contacts corresponding to the contacts GND and DATAIN are closed. When the automatic focusing lens is mounted on the camera, the data transferred to the shift register SH1 in the communication routine is all at L level. Thus, a signal of H level is produced from the gate Gl and is supplied to the input port PB4. The signal of H level supplied to the port PB4 of the CPU in the communication routine is detected in the step FEXT. Assume that a lens having an automatic focusing function is mounted on the camera. Then, the signal of H level is detected, and the flow advances to the clear accumulation charge step. Thereafter, the flow sequence from the clear accumulation step to the step FEXT is repeated. Therefore, in the case of a lens having an automatic focusing function, distance measurement add automatic focusing are performed at the lens side, and automatic focusing and direction indication are not performed at the camera side. In the case of lenses other than one having an automatic focusing function, since a signal of H level is not detected in the step FEXT, the flow advances to the direction indication step from the step FEXT. In the direction indication step, the signal representing the direction toward the in-focus position which is calculated in the direction detection operation step is supplied to the display DISP, thus indicating the focusing direction to the operator. In this manner, when a lens mounted on the camera is not a lens having an automatic focusing function, the focusing direction is indicated by the display DISP, and the flow then advances to the step FMAN. In the step FMAN, it is detected if the lens mounted on the camera is a normal lens. More specifically, it is detected if the data supplied to the input port PB5 of the CPU in the communication routine is at H level. Since a normal lens does not have contacts which are connected to the respective contacts of the camera, as shown in FIG. 6B, all the contacts are open. Therefore, data supplied to the shift register SH1 in the communication routine is all at H level, and data of H level is supplied to the input port PB5 of the CPU from the gate G2 in the communication routine. Therefore, when data of H level is detected in the step FMAN, it is determined that a normal lens is mounted on the camera. In this case, the flow returns to the clear accumulation charge step. Thereafter, the flow sequence from the clear accumulation charge step to the step FMAN is repeated to continuously perform operation (calculation) and indication of the focusing direction. For this reason, the operator can manually focus the lens by moving the focusing ring in the direction indicated by the display DISP. When a lens mounted on the camera is a specific lens (as shown in FIG. 3) which can perform automatic focusing in response to a signal from the camera, the zoom plate ZP is connected to the terminals D0 and D1 of the data selector DS2, data of H level is not detected in the step FMAN, and the flow advances to the next predict operation step. In the predict operation step, the digital signals respectively corresponding to the photocharges on the sensing portions A 3 to B -7 and stored in the internal memory of the CPU in the data store step are used to calculate the following term: ##EQU2## so as to calculate the amount of shift required to attain the in-focus position. This amount corresponds to the value of i which provides a minimum value of the term given by (2). Thus, the shift amount is calculated. However, since the method of calculating the shift amount itself is known and is not directly related to the present invention, this method will not be described. Thereafter, the flow advances to the ZOOM compensation step. In the ZOOM compensation step, the shift amount which is calculated in the predict operation step is compensated in accordance with the zoom position of the lens, so that correct focusing can be continuously performed, irrespective of the zoom state. In a zoom lens of front-element focusing type, sensitivity is different in accordance with the zoom position. Therefore, even if the lens is driven by the same amount (distance), the shift amount of the image surface cannot be set to be the same. Since the shift amount calculated in the predict operation step is an image surface shift amount, the zoom position must also be taken into account when the lens drive amount is calculated in accordance with this image surface shift amount. For this reason, in the ZOOM compensation step, the shift amount calculated in the predict operation step is calculated, i.e., the image surface shift amount is compensated for in accordance with the data supplied to the input ports PB0 to PB3 of the CPU in the communication routine. In the communication routine, the data supplied to the input terminals D0 to D3 of the data selector DS2 is supplied to the input ports PB0 to PB3 of the CPU. The zoom plate ZP has terminals ZM1 to ZM3, one of which is connected to the input terminals D0 and D1 of the data selector DS2 in accordance with the zoom ratio of the lens. As a result, in the communication routine, one of zoom data (0, 1), (0, 0), and (1, 0) is supplied to the input terminals PB0 and PB1 of the CPU. In the ZOOM compensation step, if the zoom data is (0, 1) a divisor 1 is selected. When the zoom data is (0, 0), a divisor 1.5 is selected. When the zoom data is (1, 0), a divisor 2 is selected. Then, the shift amount calculated in the predict operation step is divided by the selected divisor so as to calculate the actual (compensated) lens drive amount from the image surface shift amount. Thereafter, the flow advances to the set predict communication data step. In the set predict communication data step, a signal representing the lens drive amount calculated in the ZOOM compensation step is produced from the output ports PA0 to PA2 of the CPU, and a signal representing the drive direction of the lens toward the in-focus position is produced from the output port PA3 of the CPU. The flow then advances to the communication routine call step so as to call the communication routine again. In the called communication routine, the data produced from the output ports PA0 to PA3 of the CPU are transferred to the latch circuit LT1 and the counter DEC1 through the shift register SH2, and at the same time, the zoom data of the zoom plate ZP is supplied to the input ports PB0 to PB3 of the CPU. When this data transfer is completed, a signal of H level is produced from the gate G5 a a BUSY signal. The data produced from the output ports PA0 to PA2 represent the lens drive amount. Therefore, when a signal representing the lens drive amount is supplied to the counter DEC1, a signal of L level is produced from its DT≦0 terminal. A signal of H level is supplied to one input terminal of the gate G9 through the inverter G8. The other input terminal of the gate G9 is connected to the output terminal Q3 of the counter CNT2. Since a signal of H level is produced from the output terminal Q3 of the counter CNT2 during data transfer as described above, a signal of H level is produced from the gate G9 upon completion of the data transfer so as to turn on the switch SWm and to deactivate the motor driver MD. Upon the data transfer, data from the output port PA3 of the CPU appears at the output terminal Q3 of the shift register SH2. Since this data represents the lens drive direction as described above, the signal representing the lens drive direction is latched in the latch circuit LT1 when the data transfer is completed. This lens drive direction signal is supplied to the motor driver MD through the amplifier OP1. Thus, the motor drives the lens in the direction indicated by the signal. Upon the drive operation of the lens, the slider BR is slid on the contact plate FP so that a number of pulses corresponding to the lens drive amount are supplied to the counter DEC1. The counter DEC1 counts down the pulses from the lens drive amount signal. When the count of the counter DEC1 becomes zero, the counter produces a signal of H level from the DT≦0 terminal. Then, a signal of L level is produced from the gate G9, the m otor driver MD is deactivated, and the one-shot multivibrator ON2 is triggered. The counter CNT2 is reset, and a signal of H level is produced from the contact CLOCK The gate G5 produces a signal of L level to disable the BUSY signal. The communication routine is executed in this manner, and transfer of the lens drive amount signal is performed in synchronism with the transfer clock pulses supplied to the lens through the contact CLOCK. The lens is driven in accordance with the transferred data. After the lens is moved to the in-focus position, the flow advances to the clear accumulation charge step. Thereafter, the flow sequence from the clear accumulation charge step to the communication routine step is repeated, thereby performing automatic focusing, in accordance with the movement of an object to be photographed. According to the present invention, a BUSY signal is supplied to the camera during lens drive so as to prohibit the distance measuring operation by the photosensor. The lens drive operated in accordance with charge data on the photosensor during lens drive is prohibited, and the CLOCK contact also serves as a contact for producing the BUSY signal. Therefore, the number of contacts between the camera and the lens can be reduced to a minimum. In the present invention, the mode of the camera is automatically set in accordance with a type of lens mounted thereon, so that the camera performs an operation optimal for each type of lens. In the embodiment described above, when it is determined that a lens mounted on a camera has an automatic focusing function in accordance with the lens type data read through the above-mentioned terminal, direction indication is not performed at the camera side. Therefore, even if the distance measuring operation time at the camera side is different from that at the lens side, that at the lens side has priority and direction indication and focusing control can be performed. When a normal lens is mounted on the camera, direction indication alone is performed, and therefore the predict operation and the like are not performed. Therefore, the time required for the distance measuring operation is shortened. Description of the type of lens mounted on the camera following the read operation of the lens type data is performed by hardware comprising an AND gate and a NOR gate. However, the read data can be supplied to the input ports PB0 to PB3 of the CPU, and the operation can be performed by a program (software). In the above embodiment, with reference to FIG. 4, when the lens mounted on the camera is determined to be a lens having an automatic focusing function, the flow returns to the clear accumulation charge step 7. However, the control sequence indicated by the dotted line may be adopted.	The invention relates to an automatic focusing apparatus, particularly, of a type wherein a lens drive amount is calculated by circuits in a camera in accordance with an output from a focusing detection circuit, the calculation result is transmitted to a lens mounted on the camera, and the lens is driven accordingly. While the lens unit is driven for a distance corresponding to the calculation result, operation of the focusing detection circuit of the camera is prohibited by sending a signal for prohibiting the operation of the focusing detection circuit thereto through a contact for transferring data from the camera to the lens unit in modes other than the lens drive mode. The number of contacts between the camera and the lens unit is reduced.	6
BACKGROUND OF THE INVENTION [0001] The present invention relates to a method for continuous treatment of a textile product web with steam for fixing a reactive dye on natural fibers. [0002] It also relates to a device for continuous treatment of textile product web of this type. [0003] For fixing of reactive dyes on natural fibers, such as cotton or cellulose it is known first to dry the moist product web on which the reactive dye is applied, and subsequently to leave the dye for reaction with the fibers of the product web. For this purpose aide, such as for example urea is needed and admixed to the reactive. dye. The aide holds the reactive dye during dying in solution and evaporates during fixing. This is true both for application of reactive dye on the product web by coloring and also by pressing. [0004] For fixing of the reactive dye applied by pressing, it is known to treat the dried product web with saturated steam. A corresponding device with a steam chamber is disclosed in the patent document EP 0607 762B. For reduction of the urea consumption, this device is provided with a pre-moisturizing chamber. [0005] A reduction of the urea quantity is possible, as described in the German patent document DE 43 03 129 C2, in that the printed and dried product is sprayed with water immediately before its entry in the rapid festoon ager. This fixing process in the rapid festoon ager requires an average steam time of 10-15 minutes. The product extends amounts in general to 80-490 m, whereby a product speed is from 5 to 50 m/min. In the rapid festoon ager the fixing of the reactive dye is performed conventionally with saturated steam at substantially atmospheric pressure, or in otherwords in saturated steam atmosphere. Rapid festoon ager with a product extent of at least 80 meter is not efficient usable for smaller quantities to be covered (smaller meter lengths). [0006] A further appropriate steamer is disclosed in the German patent document DE 23 10 195 C2. This steamer has a treatment chamber and a transporting device with at least partially horizontal product guidance by means of a conveyor. The treatment chamber is formed as a downwardly open hood. Thereby the entrained air can fall from the downwardly open steam space, so that always a pure steam atmosphere is available. A fixing of a drying product web in this steam atmosphere, in which also a purely saturated steam atmosphere is provided, is not possible without urea. The advantage of this steamer is that, due to the above mentioned steam type with saturated steam atmosphere of 10-15 mm in a continuous operation, only small product speeds can be reached. Higher product speeds are possible only with greater structural length of the steamer with correspondingly higher investments and operation costs. The steam also is not efficiently usable for smaller quantities to be colored. [0007] A further disadvantage of the above mentioned method is that the product web after application of reactive dye soluble in water is first dried and subsequently the reactive dye is fixed on the fibers. The both treatment stages of drying and fixing require two treatment devices. During pressing, conventionally for drying a pressing chamber and for fixing the above mentioned steam device are utilized. [0008] In a special pressing method which is disclosed in the German patent document DE 196 33 101 the product web is moisturized, wet pressed and in wet condition evaporated without intermediate drying. The steaming is performed in a saturated steam atmosphere during 1.0-20 min at 96-105° C. Also, in this method during use of a reactive dye for printing of cotton, urea in conventional quantity is utilized. [0009] A further special pressing method in which the product web is first moisturized, the wet product web is printed and subsequently an evaporation-thermosol fixation process is performed, it is disclosed in the patent document W096/28604. The evaporation-thermosol fixation process takes place with saturated steam at temperatures of 90, 150 and 170° C. It requires a pressure-tight fixing device which conventionally is suitable only for a discontinuous operation. SUMMARY OF THE INVENTION [0010] Accordingly, it is an object of present invention to provide a method of continuous treatment of a textile product web with steam for fixing of reactor dye on natural fibers which avoids the disadvantages of the prior art and which is suitable for smaller meter lengths efficiently. [0011] In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated in a method of treatment of a textile product web with steam for fixing of reactive dye on natural fibers, which includes the steps of applying a reactive dye on moist product web of natural fibers; bringing the moist product web with the reactive dye in contact with steam; using the steam in form of hot steam which is overheated water steam, with a temperature of 130-230° C.; transporting the product web during a steam treatment at least partially horizontally through at least one treatment chamber; and blowing the hot steam into the at least one treatment chamber onto the product web by nozzle boxes arranged above and below of the product web. [0012] It is also an object of present invention to provide a device for continuous treatment of a textile product web with steam for fixing of reactive dye on natural fibers in which the inventive method can be realized. [0013] In keeping with these objects another feature of present invention resides, briefly stated at least one treatment chamber, a transporting device having a horizontal conveyor guided through the at least one treatment chamber, a steam-tight housing which surrounds the at least one treatment chamber, the at least one treatment chamber being provided with at least one circulating device with at least one circulating fan and also with nozzle boxes arranged above and below the product web, the conveyor being formed as a sieve band. [0014] When the method is performed and the device is designed in accordance with the present invention, the steam treatment can be performed effectively and thereby fast. Also, for fixing printed product webs are suitable. [0015] In a method for continuous treatment of a textile product web with steam in which a moist product web of natural fibers with an applied reactive dye is brought in contact with steam, is subjected also to steam treatment, fixing treatment or dye fixing, with the steam, in accordance with the present invention in form of hot steam, or in other words overheated water steam at substantially atmospheric pressure. The hot steam is composed at least of 80 vol. %, preferably 95-100 vol. % (pure hot steam), of water steam. The hot steam has a temperature of 130-230° C. in particular of 160-230° C. In addition to the high product web temperature which with pure hot steam amounts to 100° C., the additional temperature difference between the hot steam and the product web of 30° , in particular 60° up to 130° C. makes possible an acceleration of the reaction of the reactive dye with the natural fibers. This leads, when compared with a fixing treatment in saturated atmosphere to reduced heating and fixing time, and correspondently reduced retention time in a steamed treatment device and allows therefore devices which can be used efficiently for shorter meter length. [0016] It is important for the inventive method that with the use of hot steam, the moist product web is dried during the steam treatment. It has been shown that a drying of the product during the fixing treatment leads to an acceleration reaction of the reactive dye with the natural fibers. This results in a further reduction of the fixing time. [0017] In the event treatment method for many reactive dyes it is also possible to get rid of the use of urea. This is true for dyes of textile product webs in which the product webs colored with reactive dyes have a moisture of for example 40-80%. This is true also for the printing of textile product webs, in which the product webs printed with reactive dye have a moisture of for example 10-40%. [0018] In a surprising manner this treatment methods with hot steam and with an enhanced drying leads to a good fixing results, namely to a high color yield and a good coloring quality which corresponds to the result of the prior art. [0019] In accordance with the present invention the product web during the steam treatment is transported at least partially horizontal through at least one treatment chamber. The horizontal product web guidance makes possible a fine transportation of the moist product web with the reactive dye applied on it. In contrast to this, in a roller conveyor steamer or in a rapid festoon ager due to the vertical product web guidance there is a danger of dye running. The use of a horizontal product web guidance, which with saturation steam atmosphere with the product extent requires a great structural volumes, is usable in connection with the efficient steam treatment with heat steam also for smaller meter length. [0020] In accordance with the present invention, the hot steam in the treatment chambers is blown onto the product web by nozzle box arranged above and below the product path. Preferably, the hot steam is guided in circulating process. In contrast to the adjusting saturated steam atmosphere disclosed in the German patent document DE 23 10 195 C2 without significant flow speed, the product web is blasted with hot steam. The blasting makes possible a higher exchange rate of the treatment steam on the outer surface of the product web and thereby a stronger energy supply per time than in a stationary steam atmosphere. By the blasting, the steam treatment is further efficient and the usability of the inventive method for small meter length is improved. [0021] The utilization of hot steam when compared with saturated steam, during the blasting through a circulating system has the advantage of a lower danger of condensation in the circulating system. With the use of the inventive method for printing of textile product webs, the moisture of the printed product web before the steam treatment is adjusted to 10-40%, in particular 15-25% and the product web is dried during the steam treatment to the residual moisture of 1-10% in particular 3-7%. In surprising manner, it has been determined that with the inventive method for a printed product web, optimal fixing results can be obtained with a residual moisture of the product web smaller than the equilibrium moisture. The equilibrium moisture amounts under normal conditions to substantially 10% moisture to the weight of the product web for cellulose and substantially 8% moisture for cotton. A regulation of the residual moisture of the product web in the treatment chambers is not necessary. [0022] The retention type of the product web in the treatment chamber can be 35-60 seconds, preferably 10-20 seconds. This time is sufficient for drying and for complete fixing of good dye yield. It makes possible to provide a device with small structural dimensions. [0023] By the transportation of the product web by means of a sieve band, on the one hand a transportation of the product web through the treatment chamber can be performed without contact with the printed surfaces, and on the other hand a steam supply from above and from below on the product web is possible. [0024] An arrangement for continuous treatment is also provided in accordance with the present invention. Since it has a steam-tight housing which surrounds all treatment chambers, the use of heat steam is possible. By means of the circulating devices with at least one circulating fan and nozzle boxes arranged above and below the product web, the steam treatment with hot steam is effective also with the fine, horizontal product web guidance. [0025] The arrangement in accordance with the present invention is especially suitable for fixing of small meter lengths. [0026] The transportation of the product web by a conveyor formed as a sieve band makes possible, with a contact-free transportation of the printed circuit of the product web, a steam supplied from above and below onto the product web. The device is therefore especially suitable for dye fixing of the printed product webs. [0027] A great opening degree of the sieve band makes possible a great contact surface of the product web for hot steam. This leads to a high exchange rate and thereby to an efficient steam treatment. The deviating rollers for the conveyor formed as the sieve band arranged above the steam-tight housing simplified the construction of the arrangement. However, slots must be provided for entry and exit of the conveyor. [0028] A return guidance of the conveyor under the housing requires 32 only an inlet slot and an outlet slot for the conveyor and makes possible an arrangement of a tensioning system and a drive for the conveyor outside of the steam-tight housing. This simplifies the construction of the arrangement. A guiding band can extend at an acute angle to a vertical through the inlet lock. It can be formed by the conveyor itself or a further band. It allows deviations of the product web by an angle of greater than 90°. Thereby the danger of negatively affecting the printing image by excessive deviations of the product web, such as in the case of a deviation around 90°, is reduced. The acute angle amounts to approximately 30-60°. [0029] A supply band which extends in the vicinity of the conveyor running through the treatment chambers simplifies the supply of the starting portion of a new product web to the conveyor. [0030] A supply band which extends through the inlet lock is especially suitable for devices with a conveyor running back through the treatment chamber. [0031] In accordance with a further feature of present invention, locks are arranged before and after the housing. The locks extend from the bottom to over the transporting plane of the product web and are subdivided into a lower, downwardly open prechamber and a main chamber arranged over it. Suction passages or suction boxes can be connected with the prechamber. When compared with the known inlet and outlet slots with the suction boxes disclosed in the German patent document DE-A 195 46 344, due to the separate locks with the prechamber and aspiration device, the penetration of air and thereby condensation of steam to water is reliably prevented. A lock which is known from the German patent document DE 198 58 339, in which before the inlet slot of the housing steam is blown onto the product web, is less suitable for fixing of dye because of the danger of dye running. [0032] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0033] [0033]FIG. 1 is a view showing a device for printing a textile product web with an inventive arrangement for dye fixing in accordance with a first embodiment of the present invention; [0034] [0034]FIG. 2 is a view showing this arrangement with a schematic cross-section; and [0035] [0035]FIG. 3 shows an inventive arrangement for dye fixing in accordance with a second embodiment of the present invention also with a schematic cross-section. DESCRIPTION OF PREFERRED EMBODIMENTS [0036] A device for printing of a textile product web 1 of natural fibers, for example of cotton or cellulose, with reactive dye has units which are arranged one after the other in a transporting direction and include a product storage 2 , a supply device 3 , a printing device 40 , a device for dye fixing 6 , a further supply device 7 , and a further product storage 8 . In this example the front product storage 2 is formed as a winder, the front supply device 3 is formed as a boom, the rear supply device 7 is formed as a taking off table and rear product storage 8 is formed as a container. The printing device 40 is formed as a rotary printing press. Alternatively also another printing press can be used such as for example a flat bed printing machine or an ink-jet printing machine. [0037] The device 6 for dye fixing has an inlet lock 9 , a steam-tight heat insulating housing 1 0 , and an outlet lock 11 . The housing 10 includes one or several, preferably one to four, modular treatment chambers 12 arranged in a row. The interior of the housing 10 is subdivided by the treatment chambers 12 into one or several successive fields. The housing 1 0 is not subdivided and embraces all treatment chambers, in this example a treatment chamber 12 . [0038] A circulating device is provided in each treatment chamber 12 . It is a device for guiding hot steam in a circulation, known as a circulating process with at least one circulating fan 14 , at least one heating device which is not shown in the drawings and a nozzle box 15 with nozzle openings directed toward the product web 1 . The nozzle boxes 16 are arranged above and below the product web 1 and extend transversely over the product level 1 . In a treatment chamber 12 , one or several upper and lower nozzle boxes 15 can be arranged one after the other. In this example the treatment chamber 12 is provided with four nozzle boxes 15 arranged above and four nozzle boxes arranged below and with two circulating fans 14 . Each of the circulating fans 14 is associated with two upper and two lower nozzle boxes 15 . The upper and lower nozzle boxes 15 can be arranged so that they are offset opposite to or relative to one another. The nozzle openings of the nozzle boxes 15 are preferably formed as slots. [0039] The transporting device has a rotating conveyor which is formed as a sieve band 41 . It is guided by two upper deviating rollers 42 , 43 with its upper run through the treatment chamber 12 and by two lower deviating rollers 44 , 45 with its lower run through the treatment chamber 12 and underneath the housing 10 . The upper front deviating roller 42 is located completely in the inlet lock 9 and the upper rear deviating roller 43 is located completely in the outer lock 11 . Their arrangement is such that, the product web 1 is guided in the treatment chamber 12 flat and horizontal, or in other words in a horizontal transporting plane. One of the lower deviating rollers 44 , 45 is connected with a not shown drive. [0040] The transporting device also has a not shown, conventional tensioning device, with which the sieve band 41 is tensioned, as well as not shown supporting devices in the treatment chamber 12 . The supporting devices can be formed by a longitudinal slide arranged at the sides on the nozzle boxes 15 or by supporting rollers arranged between the nozzle boxes 15 . [0041] The sieve band 41 has an open surface over at least 50% to maximum 90%. It is composed in this example of a metal link conveyor with an open surface over 80% and has on its sides chain links. Correspondingly, the deviating rollers 43 , 44 , 45 and 46 are provided on its sides with toothed gears. Alternatively, the sieve band 41 can be formed as perforated metal band or as a glass fabric band. The housing 10 has an inlet slot 27 in a front wall 26 and an outlet slot 29 in a rear wall 28 . The product web 1 can be introduced into the housing 10 and withdrawn from it through the inlet slot 27 and the outlet slot 29 correspondingly. [0042] The inlet lock 9 has a front plate 31 which extends parallel to the front wall 26 in the vicinity of a lower edge 30 to above the inlet slot 27 , a cover plate 32 and two not shown side plates. The plates 31 , 32 of the inlet slot 9 are connected steam-tightly with one another and with the front wall 26 . The inlet lock 9 is extended by the intermediate plates 33 , 34 which extend from the front plate 31 and from the front wall 26 into the interior of the inlet lock 9 . A gap 35 is maintained between them for the product web 1 and in some cases a conveyor, so that it is subdivided into an upper main chamber 36 and a lower pre-chamber 37 . The pre-chamber 37 is open downwardly. A suction device, in this case a suction passage 38 connected with a not shown fan, is connected to the pre-chamber 37 . In some cases, a as in the shown example, a suction box 39 is provided in the pre-chamber 37 to which the suction passage 38 is connected. The deviating roller 44 of the transporting device is located directly under the pre-chamber 37 and the deviating roller 42 is located before the inlet slot 27 . [0043] The outlet lock 11 is formed analogously as the inlet lock 9 . The deviating rollers 43 , 45 are arranged analogously to those of the inlet lock 9 . The transporting device also has a guiding roller 46 which is arranged behind the deviating roller 45 for deviation of the product web 1 and for separation from the sieve band 41 , and a supply band 47 for supplying the product web 1 to the device 6 . The supply band 47 which is guided over the rollers 48 , 49 runs in this example horizontally and extends to underneath of the pre-chamber 37 of the inlet lock 9 . [0044] For printing, the product web 1 is pulled from the product storage 2 over the supply device 3 formed as boom and through the printing device 40 formed as a rotary printing press to the device 6 for dye fixing. [0045] The product web 1 is transported over the supply band 47 of the transporting device to the under the pre-chamber 37 of the inlet lock 9 . Their the sieve band 41 takes over the transportation from below to the pre-chamber 37 , through the gap 35 into the main chamber 37 , around the deviating roller 42 , through the inlet slot 37 and through the treatment chamber 12 . For this purpose the product web 1 , for example automatically is clamped on the sieve band. The product web 1 leaves the device 6 through the outlet slot 29 and the outlet lock 11 . It is supplied over the supply device 7 which is formed as a taking off table to the product storage A which is formed as a container. The product web speed amounts for example from 40 m/min. [0046] In the printing device 40 the product web I is provided with printing paste. The moist product web 1 during its transportation flatly through the treatment chamber 12 of the device 6 is acted upon by hot steam from the nozzle boxes 15 arranged above and below the product web 1 and having nozzle openings oriented toward the product web. The nozzle pressure amounts to 200-1000 PA and a thermal transmission power is substantially 240 W/m 2 . [0047] The temperature of the hot steam amounts to 1300 in particular 160° to 230° C., and the retention time of the product web 1 in the treatment chamber 12 amounts to 5-60 seconds, preferably 10-20 seconds. The residual moisture of the product web 1 when it leaves the housing 10 amounts during printing to less than the equilibrium moisture under normal conditions, or in other words it is smaller than 10%. [0048] In the treatment chamber 12 and in the main chamber 36 the inlet and outlet locks 10 , 11 are maintained with a slight overpressure. The steam content, preferably between 95 and 100 vol. percent, is maintained by changing of the quantity of the aspirated hot steam, through the suction passages 38 of the pre-chambers 37 of the input and outlet locks 9 , 11 . A regulation of a predetermined residual moisture of the product web 1 is not needed. [0049] In an example of the printing process, a product web 1 of cotton with applied printing paste as reactive dye without urea with a product web weight 80 g/m 2 is transported with a product web speed of 40 m/man through the device 6 . The temperature of the pure hot steam amounts to 100° C. The nozzle pressure at the nozzle openings of the nozzle boxes 15 amounts to 700 PA. After a retention time of 5 seconds the overwhelming part of the dye is reacted with the fibers of the product web 1 and is fixed. After further 5 seconds, the product web 1 is completely dried and the residual part of the dye is fixed. The initial moisture is reduced by approximately 20% in the device 6 to a value smaller or substantially equal to 5%. The total retention time in the device 6 amounts to 10 seconds. In the embodiment shown in FIG. 3, the device 6 for dye fixing corresponds to the previously described device. Three treatment chambers 12 are arranged in the housing 10 . Each treatment chamber 12 is provided with a circulating fan 14 and an upper and a lower nozzle cast 15 . [0050] The transporting device also has a circulating conveyor formed as a sieve band 51 , which in contrast to the first example is guided over two deviating rollers 52 and 53 with its upper and with its lower run through the treatment chambers 12 . In other words the conveyor is supplied back through the treatment chambers 12 . Also the deviating roller 52 is located completely in the inlet lock 9 and the deviating roller 53 is located completely in the outlet lock 11 . Their arrangement is such that the product web 1 is guided in a horizontal transporting plane. The deviating roller 53 in the output lock 11 is connected with a not shown drive. In the outlet lock 11 a not shown tensioning device for the conveyor is located. [0051] The transporting device is also provided with transporting rollers 54 in the field abutments, or in other words in the regions in which the treatment chambers 12 abut against one another. [0052] The input lock 9 of this device 6 for dye fixing extends at an acute angle to a vertical. For this purpose the front plate 31 is arranged at this acute angle to the vertical and the not shown side plates are correspondingly shaped. The intermediate plate 34 extending from the front wall 26 is extended in correspondence with the deviation of the plate 31 and has at least front end such an edge 55 that it ends opposite to the intermediate plate 33 extending from the front plate 31 . Also, the nozzle box 39 extending from the front wall 26 is correspondingly elongated and edged. [0053] The transporting device has in this example a guiding roller 56 at the outlet of the outlet lock 11 and a supply band 57 . The supply band 57 is guided over two rollers 58 , 59 , extends parallel to the front plane 31 and extends through the front chamber 37 and the main chamber 36 of the inlet lock 9 . In other words the supply band 57 forms a guiding band which runs at an acute angle to the vertical through the inlet slot 9 . The gap 35 between the intermediate plates 33 , 34 and the distance between the suction boxes 39 is formed correspondingly wide. The upper roller 59 of the supply band 58 is arranged substantially before and substantially above the deviating roller 52 and the roller 56 before the pre-chamber of the input lock 9 . [0054] During printing, the moist product web 1 provided with the printing paste is transported over the supply band 57 through the inlet lock 9 , placed on the sieve band 51 from above and transported on the sieve band 51 through the treatment chambers 12 to the outlet lock 11 . From the outlet lock 11 , the product web 1 is withdrawn over the guiding roller 57 . [0055] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. [0056] While the invention has been illustrated and described as embodied in METHOD OF AND DEVICE FOR CONTINUOUS TREATMENT OF A TEXTILE PRODUCT WEB WITH STEAM FOR FIXING REACTIVE DYE ON NATURAL FIBERS, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. [0057] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.	A of continuous treatment of a textile product web with steam is performed by applying a reactive dye on moist product web of natural fibers; bringing the moist product web with the reactive dye in contact with steam; using the steam in form of hot steam which is overheated water steam, with a temperature of 130-230° C.; transporting the product web during a steam treatment at least partially horizontally through at least one treatment chamber; and blowing the hot steam into the at least one treatment chamber onto the product web by nozzle boxes arranged above and below of the product web. The device is also provided for performing the method.	3
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber crimping apparatus which is designed to give waves to the synthetic fibers formed straight by fiber drawing devices, and particularly the fiber bundles are delivered out into the stuffing box by means of two nip rollers which press against each other. 2. Description of the Prior Art The conventional fiber crimping apparatus equipped with two nip rollers is of two kinds; the one kind, as referred to in U.S. Pat. Nos. 3,096,558, 3,137,055 and 3,248,770, is an outer contact type in which fiber bundles are passed between two rollers the outer surfaces of which are pressed against each other and rotate at the same speed; the other kind, as referred to in U.K. Pat. No. 1,408,235, is an inner contact type in which a ring roller, the inner surface of which is formed on the contacting surface, is made to contact the internally contacting roller, which has an eccentric rotating shaft and the outer surface is formed on the contacting surface and a crescent shaped stuffing box is formed between the two rollers. The above-mentioned outer contact type conventional apparatus has a drawback that the nip zone, which is formed in the front and the rear of the roller contacting point, is too short. On the other hand, the internally contacting type has such the advantage that the nip zone can be larger. In the outer contact type conventional apparatus, the fibers tend to scatter along the rotating direction of each roller when they pass the place of contact of the rollers and enter the stuffing box. For preventing such scatter of fibers, it was necessary to fit a scraper to each roller and lead the fibers to the stuffing box exactly. But, the fibers are pressed out through a gap of the scraper at so high rate that very delicate processing and assembling adjustment were required for preventing such pressing out of the fibers. Further, because of such structure that the stuffing box situated at the rear of the rotating direction of the roller was surrounded by fixed side walls, there were such defects as the fibers fly out of the stuffing box through a gap between the side walls and the roller and/or friction heat is produced by a difference in velocity at the time when the bundles of fibers fed into the stuffing box at a high speed come in contact with the fixed side walls and thus the fibers are damaged. For that reason, it has been expected to improve the crimping apparatus in order to eliminate the abovementioned defects of the crimping apparatus of a roller system and to speed up crimping process. This sort of drawback also exists in the internal contact roller type apparatus. That is in this type apparatus in which a crescent shaped stuffing box is formed between the two rollers that contact internally and one side of the said box which is open, is closed with a cover plate; one side out of four sides is formed by a fixed wall surface, a small gap is formed between the said cover plate and the two rotating rollers, and the abovementioned facts caused such troubles as the fiber escapes out of the box through the said gap, the flowing fibers generate heat by contacting the cover plate, all of which affect the production of uniform crimp. For this reason, there has been a problem of eliminating the drawback of mechanical fiber feeding using two rollers, of speeding-up of the crimping process and of developing an apparatus which enables production of crimped yarn of more uniform crimping and highly reliable results. SUMMARY OF THE INVENTION This invention provides a fiber crimping apparatus characterized in that it consists of a ring roller of a comparatively large diameter rotating in one direction and another roller, which is installed to contact the said roller internally, and which, while holding the fiber bundle between itself and the said roller, rotates in the same direction at the same surface speed; a side ring, which rotates in the same direction at the same speed with the said two rollers, is installed on both sides of the contacting points of the said two rollers to let the inner surface of the side ring at both sides and the contact surface of the two rollers form a stuffing box having four surfaces which run continuously at the rear part of the direction of rotation of the said contact point. In the apparatus according to the invention, constructed as described above, a pair of outer and inner rollers, which hold the fibers to be crimped, rotate in the same direction at the same speed. The fiber bundle, which becomes flat while being pressed by two rollers, is fed into the stuffing box, being guided on both front and back sides by the double rotating surfaces of the inner and outer roller the direction of rotation of which is the same even after pressing with each other. And the fiber bundle, which becomes flat, between the two rollers, is lead into the inner surface of the side ring which rotates in the same direction at the same speed, and therefore there will be no heat generation as in the case of the fixed surface, there will be no flow of the fibers from the gap, and the fibers are guided in good order into the stuffing box. In this way, the four surfaces that form the stuffing box run in the flowing direction of the fibers, the difference of the speed is made small to prevent generation of heat by friction and to prevent the fibers from flowing out, which enables crimping to be carried out at a higher speed, thus eliminating the drawbacks of the conventional apparatus. BRIEF DESCRIPTION OF THE DRAWINGS The drawings show the examples of embodiment of the present invention: FIG. 1 is an oblique view to show the working example I of the present invention; FIG. 2 is an elevation with partial cut-off of FIG. 1; FIG. 3 is a plane view with partial cut-off of FIG. 2; FIG. 4 is an elevation with partial cut-off at the time when releasing the contact of the inscribed roller with the ring roller in order to hold the bundles of fibers between the two rollers in the working example I; FIG. 5 is an elevation with partial cut-off to show the state that the bundles of fibers are crimped due to the contact with the crimp resisting object in the working example I; FIG. 6 is an elevation to show the state that the amount of the crimped bundles of fibers increases and that the crimp resisting object moves backward and that the crimped bundles of fibers are discharged from the machine successively; FIG. 7 is an elevation with partial cut-off to show the working example II; FIG. 8 is a plane view with partial cut-off of FIG. 7; FIG. 9 is a magnified elevation to show the important points of FIG. 7; FIG. 10 is a plane view with partial cut-off of FIG. 9; FIG. 11 is a vertical sectional side view to show the state that one of the two side rings is formed by the hub of the ring roller and that the other side ring is fitted to the other side of the ring roller as one body; FIG. 12 is a vertical side view to show the state that the side rings are formed on both sides of the inscribed roller respectively as one body; and FIG. 13 is a vertical sectional side view to show the state that one side ring is formed on one side of the inscribed roller and that the hub of the ring roller acts as the other side ring. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Now, the apparatus made according to the invention is explained below with references to the preferred in FIGS. 1-13 of the attached drawings. In the working example I shown in FIGS. 1-6, (1) is a ring roller with a L-shape section which is formed as one body by the outer surface of a hub (1") fitted on a rotary shaft (2) laid on one side of a machine stand (F) in a cantilever state, and an open side of which is fitted with a side ring (1') formed separately, and which is rotated by a transmitting device (3); (4) is an intermediary rotary shaft laid on a supporting department (S) of a machine stand (F') in parallel with said rotary shaft (2); (5),(5) are swing arms, each of which is loosely put on said intermediary rotary shaft (4) in such way as they can swing freely with the rotary shaft (4) as a fulcrum; (6) is a swing bearing matter held firmly between the inner part of the top of the swing arms (5), (5); (5') is a swing frame of a channel shape with one side open (shape), both ends of which are loosely put on a rotary shaft (7) provided in such way as it passes through the swing arms (5),(5) and the swing bearing matter (6), and which can swing freely with said rotary shaft (7) as a fulcrum; the rotary shaft (7) is fitted on its one end with a gear (b) which engages with a gear (a) fixed to the outer end of the intermediary rotary shaft (4) and is fitted on its outer end with an inscribed roller (8) for contacting the ring roller (1) internally; (9) is a fluid pressure device, the upper end of which is connected to the swing bearing matter (6) and which pushes the inscribed roller (8) to the ring roller (1) or pull the former apart the latter by expanding or contracting; (10) is a crimp resisting object, the base of which is supported on one side of the top end of the swing frame (5'), and the top of which is placed adjacent to the place of contact of the ring roller (1) and the inscribed roller (8), and which can move freely and elastically; (11) is the second fluid pressure device, the upper end of which is connected to the top end of the swing frame (5'), and which supports the crimp resisting object (10) elastically; (12) is a stuffing box formed at the rear of the rotating direction of the place of contact of the ring roller (1) and the inscribed roller (8). The stuffing box (12) in the working example I is surrounded on its four sides by the inner surface of the ring roller (1), the outer surface of the inscribed roller (8), the side ring (1') fitted on one side of the ring roller (1), and the abovementioned hub (1") which acts as the other side ring. And at the rear of it, the said crimp resisting object (10) is situated; (13) is a fiber feeding department formed in the front of the rotating direction of the place of contact of the ring roller (1) and the inscribed roller (8); (m) is a bundle of fibers which is fed from the feeding department (13) and held between the ring roller (1) and the inscribed roller (8) and flattened due to the pressure of the two rollers and fed into the stuffing box; (17) is a guide for the bundles of fibers (m) provided outside the feeding department (13). The rotary shaft (7) of said inscribed roller (8) moves in accordance with a main shaft (16) laid at the lower part of the machine stand (F') through a driving shaft (14) having a gear (c) which engages with said gear (b) through intermediate gear (a) and another transmitting device (15) which drives said driving shaft (14), and it rotates in such way as the peripheral velocity of the outer surface of the inscribed roller (8) conforms to the peripheral velocity of the inner surface of the ring roller (1) which rotates through said transmitting device (3). In the working example I having a structure as stated above, the bundles of fibers (m) are held flat between the ring roller (1) and the inscribed roller (8) which rotate in the same direction at the same velocity and are fed into the stuffing box (12). When leaving the place of contact of the two rollers (1) and (8), the bundles of fibers (m) are given a movement in the same direction and the same velocity. By means of both the side ring (1') and the hub (1"), which also has the function of the other side ring, movement in the same direction and at almost the same speed is given. The bundles of fibers thus flattened come into contact with the crimp resisting object (10) and cause the same crimping action as seen in the case of conventional crimping apparatus of roller system. As the amount of the bundles of fibers crimped in a folded over state in the stuffing box increases, said crimp resisting object (10) resists the second fluid pressure device (11) and moves backward along the inner surface of the ring roller (1) elastically together with the top of the swing frame (5') which moves with the other rotary shaft (7) as a fulcrum. Thereby, a side of the stuffing box (12) is open wide and the crimped bundles of fibers (m) are discharged from the head successively sideward through a gap between the ring roller (1) and the inscribed roller (8) which are opened at the rear of the stuffing box (12). Said second fluid pressure device (11) repeats such actions as moving forward again the crimp resisting object (10) which has decreased resistance due to the said discharge of the bundles of fibers (m) and moving it back when the resistance increases in accordance with the feed of the bundles of fibers (m). Further, the other fluid pressure device (9) is operated when holding the bundles of fibers (m) between the rollers (1) and (8) in such way as it separates the inscribed roller (8) from the place of contact and holds the bundles of fibers (m) elastically. Now, the working example II is described below with referenced to FIGS. 7-10. The working example II is different from the working example I in such point as the side ring (1') is formed as one body on both sides of the inscribed roller (8) and in such point as two crimp resisting objects (10a), (10b) are provided on both sides of the rear of the stuffing box in such way as the distance between the insides of the resisting object (10a), (10b) facing each other is made a resisting space (18), having a wide entrance and a narrow exit to suit crimping of the bundles of fibers (m). In the working example II, both sides of the place of contact of the ring roller (1) and the inscribed roller (8) are closed by the side rings (1'),(1') which are respectively fitted on both sides of the inscribed roller (8) as one body and which rotate together with the inscribed roller (8), and the bundles of fibers (m) are led to the resisting space (18) formed between the two crimp resisting objects (10a) and (10b) provided at the rear of the stuffing box (12), and then the crimped bundles of fibers (m) are discharged successively sideward through a gap between the ring roller (1) and the inscribed roller (8) which are opened at the rear of the crimp resisting objects (10a), (10b). The ring roller (1) in the working example II is rotated, same as in the working example I, by fitting the hub (1") on the rotary shaft (2) laid on one side of the machine stand (F) in a cantilever state. Further, the inscribed roller (8) is fitted, same as in the working example I, on the rotary shaft (7) which passes through the swing arm (5) swung by the action of the fluid pressure device (9) with the intermediary rotary shaft (4) as a fulcrum and the swing bearing matter (6) provided at the top of said swing arm (5). The gear (b) situated at the outer end of said rotary shaft (7) engages with the gear (a) situated at the outer end of the intermediary rotary shaft (4). The rotary shaft (7) is connected with the main shaft (16) through a driving shaft (14) having a gear (c) which engages with the gear (a) and the transmitting device (15). The inscribed roller (8) is rotated at the same velocity at the place of contact with the ring roller (1) driven by said main shaft (16) through another transmitting device (3). Between said two crimp resisting objects, one resisting object (10a) is fitted its base on the outside of said swing arm (5) and comes close or parts from the ring roller (1) together with the inscribed roller (8) by the action of said fluid pressure device (9). The other crimp resisting object (10b) is fixed its base on the swing arm (5') provided at the top of a supporting lever (19) extended from the machine stand (F') in such way as it can swing freely and is supported in a fixed position at the rear of the stuffing box by another fluid pressure device (11), the top of which is connected to the swing arm (5') and which is supported in the middle of said fluid pressure device (9) and engages in contacting and parting from the bundles of fibers (m) before and after crimping process and adjusting the fixed position. Further, (13) is a fiber feeding department formed in the front of the rotating direction of the place of contact of the ring roller (1) and the inscribed roller (8); (17) is a guide for feeding the bundles of fibers (m) to be crimped to the feeding department (13). When carrying out the present invention, the shape or style of the crimp resisiting object (10) is not limited to what is described in the working example. It may vary depending upon the nature of the fiber to be crimped or the processing speed. When working the present invention, it is optional according to the property of the material to be processed or the speed of processing whether the crimp resisting object (10) is provided in a freely movable state or in a fixed state. It is also optional to place the crimp resisting object (10) along the outer surface of the inscribed roller (8) or along respectively the inner surface of the ring roller (1) and the outer surface of the inscribed roller (8). Its shape and other things too are optional. Further, it is optional in accordance with the essentials of the present invention to form one side ring (1') on one side of the inscribed roller (8) and to let the hub (1") of the ring roller (1) act as another side ring (1'). As stated above, according to the present invention in which the bundles of fibers to be crimped are held between the ring roller and the inscribed roller provided in order to contact said ring roller internally and the two rollers are rotated in the same direction to each other and the four sides of the stuffing box is formed by closing both sides of the place of contact of said two rollers by the side rings which rotate in the same direction at the same velocity, the surface and back of the bundles of fibers flattened by the pressure of the rollers are led to the rotating surface of the rollers running in the same direction when the bundles of fibers part from the place of contact and both sides of the bundles of fibers too are led to the inner surface of the side rings which rotate in the same direction at the same velocity, as the result of which the bundles of fibers are fed into the stuffing box in good order without breaking their flat belt shape and preventing the flying out of fibers from the surface of the flattened belt shape. In other words, according to the present invention, the four sides of the stuffing box go forward in the running direction of the fibers, so that no disorder of the fibers or no production of friction heat as seen in the case of conventional devices takes place. Accordingly, the present invention has such effects as the speed of crimp processing can be increased remarkably and it is very suitable for the speed-up of the machine operation.	Apparatus for crimping fibers comprises a ring roller of a comparatively large diameter which rotates in one direction and an inscribed roller which contacts the inner surface of said ring roller and which rotates in the same direction at the same velocity as the ring roller while holding bundles of fibers to be crimped between the two rollers and side rings which are situated on both sides of the place of contact of the two rollers and which rotate in the same direction at the same velocity as these rollers, and by forming the surrounding of a stuffing box by said rollers and rings.	3
BACKGROUND [0001] The disclosure relates generally to disk images, and more specifically to modifying disk images. SUMMARY [0002] According to one embodiment of the disclosure, a method includes identifying a first boot configuration type for a disk image. The disk image includes a master boot record and a disk partition. The disk partition comprises a volume boot record. The master boot record comprises first instructions for loading an operating system, and the volume boot record comprises second instructions for loading the operating system. The method further includes receiving an input indicative of a second boot configuration type. The method also includes modifying the disk image to use the second boot configuration type to load the operating system by modifying the first instructions and the second instructions. [0003] Other features and advantages of the present disclosure are apparent to persons of ordinary skill in the art in view of the following detailed description of the disclosure and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0004] For a more complete understanding of the configurations of the present disclosure, needs satisfied thereby, and the features and advantages thereof, reference now is made to the following description taken in connection with the accompanying drawings. [0005] FIG. 1 illustrates a block diagram of a system for modifying disk images in accordance with a non-limiting embodiment of the present disclosure. [0006] FIG. 2 illustrates a flowchart of a method for modifying disk images in accordance with a non-limiting embodiment of the present disclosure. [0007] FIG. 3 illustrates a block diagram of a system for modifying disk images in accordance with another non-limiting embodiment of the present disclosure. [0008] FIG. 4 illustrates a block diagram of disk blocks of a disk image implementing the Grand Unified Bootloader (“GRUB”) version 1 in accordance with a non-limiting embodiment of the present disclosure. [0009] FIG. 5 illustrates a block diagram of disk blocks of a disk image implementing GRUB version 2 in accordance with a non-limiting embodiment of the present disclosure. DETAILED DESCRIPTION [0010] As will be appreciated by one skilled in the art, aspects of the present disclosure may be illustrated and described herein in any of a number of patentable classes or context including any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Accordingly, aspects of the present disclosure may be implemented entirely hardware, entirely software (including firmware, resident software, micro-code, etc.) or combining software and hardware implementation that may all generally be referred to herein as a “circuit,” “module,” “component,” or “system.” Furthermore, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer readable media having computer readable program code embodied thereon. [0011] Any combination of one or more computer readable media may be utilized. The computer readable media may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an appropriate optical fiber with a repeater, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. [0012] A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable signal medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, radio frequency (“RF”), etc., or any suitable combination of the foregoing. [0013] Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language, such as JAVA®, SCALA®, SMALLTALK®, EIFFEL®, JADE®, EMERALD®, C++, C#, VB.NET, PYTHON® or the like, conventional procedural programming languages, such as the “C” programming language, VISUAL BASIC®, FORTRAN® 2003, Perl, COBOL 2002, PHP, ABAP®, dynamic programming languages such as PYTHON®, RUBY® and Groovy, or other programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider) or in a cloud computing environment or offered as a service such as a Software as a Service (SaaS). [0014] Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatuses (systems) and computer program products according to aspects of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable instruction execution apparatus, create a mechanism for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. [0015] These computer program instructions may also be stored in a computer readable medium that when executed can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions when stored in the computer readable medium produce an article of manufacture including instructions which when executed, cause a computer to implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable instruction execution apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatuses or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. [0016] Disk replication and data migration processes for replicating physical and virtual systems to portable disk images are important system management components. These processes are particularly important as organizations increase their use of virtualization. Organizations may migrate and/or replicate disks between physical machines and virtual machines. Organizations may also migrate and/or replicate disks from physical to virtual machines and from virtual to physical machines. Some replicated disk images are produced for use in specialized systems, configured to maximize performance and efficiency for a specific use. For example, a replicated disk image from a physical machine may be migrated for use in an embedded system. However, hardware specifications such as disk capacity or medium for the target system may be different than the master system. Additionally, system boot performance on the target system may be more critical than boot performance on the master system. For example, areas of the master disk between partitions that are left blank may be used for storing a boot volume for the target disk. As another example, a chained boot loader configuration from the master system may be less desirable than a higher performance boot configuration that may enable faster boot times on the target system. [0017] With reference to FIG. 1 a system 2 for modifying disk images is illustrated in accordance with a non-limiting embodiment of the present disclosure. System 2 includes computer 104 , network 14 , and master computer 150 . Computer 2 includes memory 108 , data storage 90 , processor 80 input/output (“I/O”) 70 and display 60 . In certain embodiments, master computer 150 generates a disk image of itself (e.g., a replica image) and sends it to computer 104 via network 14 . The replica image contains a snapshot of data storage 170 , including master boot record (“MBR”) 172 , boot loader 180 , disk partition 174 and operating system 176 . Computer 104 processor 80 loads modification process 112 into memory 108 from data storage 90 . Modification process 112 loads the replica image into memory and determines aspects of the replica image such as boot configuration, partition size and partition file system formatting. Modification process 112 presents the user with a graphical user interface (“GUI”) that contains, for example, the current boot configuration, partition size, and partition file system formatting. The user may select a desired boot configuration and/or desired partition file system formatting. Modification process 112 modifies the replica image according to the user selections by modifying the master boot record, volume boot record, and partition configuration of the replica image. The result of one or more of these operations is modified disk image 92 , which may remain in memory, be sent to another computer or device, or be stored on an internal disk drive. [0018] In certain embodiments, computer 104 may be a virtual appliance, virtual machine, server, virtual server or other device. Modification process 112 may use input/output 70 to display and/or receive input from a GUI. In certain embodiments, modification process 112 may receive input from a configuration file or hard coded instructions regarding which boot configuration is desired for use in the replica image. [0019] In certain embodiments, master computer 150 may include a process for generating disk images of itself and/or other systems connected to network 14 . In certain embodiments, a system connected to network 14 may generate replica disk images of master computer 150 , including replica images of virtual systems running on master computer 150 . [0020] In certain embodiments, modification process 112 may generate replica images of master computer 150 . For example, modification process 112 may create and/or have access to a workspace for modifying master computer 150 disk images. In certain embodiments, the workspace may be located on data storage 90 . In certain embodiments, the workspace may be an appliance connected to network 14 . Modification process 112 may boot an appliance and modify disk images using the appliance. [0021] In certain embodiments, data storage 170 may have varying configurations. For example, data storage 170 has one or more chain boot loaders linked together to load a variety of operating systems. As another example, data storage 170 may have any number of disk partitions containing any number of operating systems and file system formats. Master boot record may be configured to load boot loader 180 , or may load a boot loader directly from disk partition 174 or any other disk partition. [0022] In certain embodiments, a user may select a disk partition file system format, disk partition size, number of disk partitions, and any other disk partition configuration options in addition to the boot configuration options. For example, the user may wish to expand the size of disk partition 174 in modified disk image 92 to fit a larger hard drive on a target machine on which modified disk image 92 will be loaded on to and/or used on or with. [0023] In certain embodiments, the GUI may present the user with several boot configurations. For example, the GUI may permit the user to select between Grand Unified Bootloader (“GRUB”) version 1 and GRUB version 2 boot configurations. The GUI may indicate that the current replica image boot format is GRUB version 1, but the user would prefer to modify the replica image to use GRUB version 2 to take advantage of the increased boot performance capabilities. Modification process 112 may locate and modify the master boot record of the replica disk image in order to directly load a volume boot record in the disk partition. The volume boot record contains a boot loader. The boot loader may load an operating system kernel from the disk partition into memory and execute it. [0024] In certain embodiments, Linux Physical to Virtual (“P2V”), Virtual to Physical (“V2P”), and Physical to Physical (“P2P”) software may migrate an operating system to a raw disk image. Such software may additionally configure the operating system disk images such that that are bootable on various host environments. For example, on a Linux system the kernel images are usually stored in a specific partition called the boot volume. When migrating an operating system to an embedded system, a user may prefer to switch the file system of the target boot volume from ext4 to reiserFS. The user may consider efficiency of smaller files and performance requirements for the embedded system when determining what file system format to migrate to. [0025] In certain embodiments, teachings of the present disclosure may enable users to modify the boot configuration of operating systems migrated and/or replicated using P2V, V2P, and/or P2P software, thus allowing the user to optimize efficiency and performance for the migrated system, while maintaining the boot configuration of a master, host, test, and/or development environment. [0026] In certain embodiments, disk image may refer to any single file or storage device that contains the data and structure of any data storage medium, such as a disk or tape. [0027] References to disk, hard disk, disk image, disk drive, or the like in the present disclosure may refer to one or more of a hard drive, tape drive, floppy disk, optical disk, solid state drive, USB drive, virtual storage drive, virtual disk drive, or any other storage medium or virtual structure representing a storage medium. References to appliance, virtual appliance or virtual machine may refer to any virtual representation of a computing system. Further, use of any of these terms or related terms in example embodiments of the present disclosure should not limit the scope of the disclosure to those example systems. For example, an embodiment discussing a migration process implemented on a virtual appliance may be implemented on a physical machine, or any combination of physical and virtual machines. [0028] FIG. 2 illustrates a system 200 for modifying disk images in accordance with a non-limiting embodiment of the present disclosure. With reference to FIG. 2 , system 200 determines a first boot configuration of a disk image. In certain embodiments, computer 104 creates the disk image. Computer 104 may receive and/or retrieve the disk image from another device on network 14 . [0029] The boot configuration may be determined by examining boot sectors and partitions of the disk as discussed below. For example, the blocks of a disk image are inspected for segments, sectors, operating systems, and partitions. If instructions or code in the master boot record is configured to load data from the disk padding in between the master boot record and the first disk partition, modification process 112 from FIG. 1 may determine that the disk image has a GRUB version 1 boot configuration. Modification process 112 may verify this by following the memory address trail to the disk padding between the partition and the master boot record to determine whether GRUB stage 1.5 boot loader is present. Modification process 112 may additionally verify that the GRUB stage 1.5 boot loader is configured to load a GRUB stage 2 boot loader from a boot sector at the beginning of a disk partition. In certain embodiments, errors in the boot loader may be identified and displayed to the user. [0030] In certain embodiments, modification process displays a mapping of the boot configuration parameters and disk partition parameters to the user. In other embodiments, the user merely selects the preferred boot configuration from a list of boot configurations presented via a web page or display. [0031] At step 220 , modification process 112 from FIG. 1 receives input from a user that specifies a target boot configuration. The target boot configuration corresponds to the configuration the user desires to apply to a target disk image. In certain embodiments, the input may be received from an XML file or some other program that sends parameters from a configuration file, database, or hard coded instruction to modification process 112 describing which boot configuration the disk image should use. In certain embodiments, a user enters the target boot configuration in addition to other boot configuration parameters and partitioning parameters into a web page. [0032] At step 230 , the disk image is modified to use the boot configuration received during step 220 . For example, modification process 112 may modify master boot record code to load a GRUB stage 2 boot loader from a volume boot record located in the beginning of a disk partition. In this example, the volume boot record may also need to be modified to load the operating system since partition configuration changes may affect the physical location of operating system kernel files. As another example, modification process 112 may modify master boot record code to load a GRUB stage 1.5 boot loader from a separate partition. In other examples, an existing GRUB stage 1.5 boot loader may be modified to load a different GRUB stage 2 boot loader from a different partition. In this example, the master boot record may not require modifications. [0033] In certain embodiments, other aspects of the disk image may be modified. For example, the size and location of various partitions may be modified using modification process 112 . This may be accomplished by copying disk blocks from one physical memory address on the disk image to another. Modification process 112 must modify boot loaders and other components if such a change is made to the physical location of the operating system kernel, since these memory blocks are required for operating system startup. [0034] FIG. 3 illustrates a block diagram of a system for modifying disk images, in accordance with a non-limiting embodiment of the present disclosure. With reference to FIG. 3 , a system contains a master system 320 , master disk 310 , appliance 330 , and replica disk 340 . Disk block diagram 350 shows the disk blocks that may be modified during the modification process. In certain embodiments, master system 320 gathers a protected volume's information (e.g., partition, boot configuration, boot style, etc.) and sends them to appliance 330 . A program or process may run in memory on master system 320 in order to send the volume information to appliance 330 . Appliance 330 creates replica disk 340 and partitions and formats them as specified by master system 320 . For example, master system 320 may determine the layout and disk mapping configuration for the replica disks. [0035] Master system 320 synchronizes the MBR and boot loaders of replica disk 340 . For example, if any formatting or configuration modifications are made to replica disk 340 , master system 320 synchronizes and coordinates those modifications with the MBR and/or GRUB stage 1.5, GRUB stage 2, etc. Master system 320 may additionally determine which sector of replica disk to write or store any boot loader or operating system file. [0036] Master system 320 synchronizes and replicates files in the boot volume and any operating system or storage volume on to Appliance 330 . Appliance 330 may write the incoming disk image data from master system 320 to replica disk 340 . [0037] In certain embodiments, volume snapshot technology may be used to generate directory snapshots as windows. This may allow the freeze and unfreeze process to be removed. For example, certain volume snapshot software periodically scans a hard disk or disk image and updates a shadow copy of the disk. The snapshot software may even scan locked memory blocks. Thus, an up to date shadow copy of the disk or disk image may be available, and the whole disk may not need to be scanned in order to replicate the disk. [0038] In certain embodiments, appliance 330 invokes a GRUB command to modify fields in the MBR, or any GRUB stages and/or other boot loaders. For example, appliance 330 modifies the disk blocks on the replica disk as depicted in disk block diagram 350 . [0039] In certain embodiments, appliance 330 may use driver injection. For example, appliance 330 may repackage a file in replica disk 340 boot volume to replace the serial computer system interface (“SCSI”) drive for replica disk 340 . [0040] Appliance 330 may modify other files in replica disk 340 . For example, appliance 330 may modify the file systems table in a Linux operating system. Replica disk 340 may then be bootable after completion of some or all of the above enumerated steps. [0041] FIG. 4 illustrates a block diagram of disk blocks implementing GRUB version 1 in accordance with a non-limiting embodiment of the present disclosure. In certain Linux distributions, such as Red Hat and SUSE, the default operating system boot loader is GRUB. In such configurations, the MBR contains a field to indicate where the first sector of the next stage (e.g., GRUB stage 1.5 or GRUB stage 2) is located. [0042] In certain embodiments, the MBR loads the next GRUB stage sector into memory and executes the loaded boot loader code, which in turn instructs the processor to load the rest of the its code from disk into memory. [0043] Varying embodiments may contain one of several boot configurations. The following examples show two such configurations. [0044] With reference to FIG. 4 , on system startup the processor is configured to load instructions from the MBR by default. These instructions tell the processor to load the GRUB stage 1.5 disk block code, which then instructs the processor to load the GRUB stage 2 disk block code. [0045] In certain embodiments, replication process 112 from FIG. 1 may write the contents of the GRUB stage 1.5 that is specific to the file system format of the boot volume immediately adjacent to the MBR in the unallocated disk space (i.e., padding). GRUB stage 1.5 files may be bundled with a specific file system because of the small size of the disk paddings, e.g., around 30,000 Bytes. [0046] In certain embodiments, the GRUB stage 1.5 code may be small enough to fit into the padding hole, i.e., the unallocated disk space, on the disk image. GRUB stage 1.5 instructions search the GRUB stage 2 file in the boot volume and recognize the file system format of the boot volume. The GRUB stage 1.5 code then loads the GRUB stage 2 code into memory. Due to the limited size constraints of GRUB 1.5 sectors, the GRUB stage 1.5 code may not be able to recognize all such file system formats or boot configurations. [0047] In certain embodiments, during execution of the GRUB stage 2 code, the operating system kernel will be loaded into memory and executed. GRUB stage 2 code may be significantly more robust than the GRUB stage 1.5 code because GRUB stage 2 may not have the same size constraints that GRUB stage 1.5 code has. GRUB stage 2 code may not be stored in disk padding between partitions, and thus may have a much larger memory size. Additionally, GRUB stage 2 code may be scattered in different areas of the disk, and can direct the processor as to where to load other GRUB stage 2 instructions from. [0048] FIG. 5 illustrates a block diagram of disk blocks implementing GRUB version 2 in accordance with a non-limiting embodiment of the present disclosure. With reference to FIG. 5 , the system starts up and loads instructions from the MBR into memory. The MBR code instructs the processor to directly load the date from the GRUB stage 2 disk blocks into memory. [0049] In certain embodiments, GRUB stage 1.5 may not be loaded into memory during the system startup process. For example, the MBR can load the first sector of GRUB stage 2 into memory. The GRUB stage 2 code identifies other locations in the disk that contain additional GRUB stage 2 code. [0050] In certain embodiments, the master system may analyze its own MBR. For example, the master system may determine the sector that the MBR is being written to on the migrated disk. As another example, the MBR may identify which GRUB version and/or stage type that the MBR is configured for. Based on this information, the GRUB stage 1.5 can be written in the correct location on the replica disk, and modifications to the placement of GRUB sectors and the MBR can be made by modification process 112 . In certain embodiments, these modifications are made with GRUB commands invoked at the command line. In other embodiments, code scripts designed to modify fields in the MBR, GRUB stage 1.5 and/or GRUB stage 2 code are run. [0051] In certain embodiments, the present disclosure may enable and/or assist a system administrator in facilitating migration of disk images to a variety of boot configurations. For example, an administrator may use a specific partition for GRUB state 1.5. The administrator may want the MBR to load GRUB stage 2 directly instead of through an extra GRUB stage 1.5. Using aspects of the present disclosure, the administrator may create a disk image using the desired boot configuration while keeping the operating system and other partitions from the master disk. [0052] In certain embodiments, the partitions on a replica may be different than the master disk. For example, a user replicating a disk image may want to make some changes to the partitions of the replica. In this example, the master disk may not have a specific partition to store GRUB stage 1.5, which is sometimes stored in the padding between the MBR and the first partition. The user may want the replica to have a separate disk partition to store GRUB stage 1.5. Certain embodiments of the present disclosure may enable those of skill in the art to modify partitions on the replica disk. [0053] As another example, a master disk may have a GRUB stage 1.5 that loads GRUB stage 2. A user may want to change the boot configuration of the replica image. For example, the user may want to eliminate the GRUB stage 1.5 on the replica. Aspects of the present disclosure may enable one of ordinary skill in the art to modify the boot configuration to accomplish this, such as by modifying the MBR to load the GRUB stage 2 directly on the replica disk. [0054] In certain embodiments, a GUI may be provided to allow for modifying the disk of the replica with a desired layout. In certain embodiments, a virtual appliance may be used to facilitate creation of the replica disk. For example, the virtual appliance migrates a master disk image to a replica disk image and may format partitions of the replica disk image. The virtual appliance may format the boot partition with a specified file system format that may be different from the file system of the boot partition on the master disk. The virtual appliance may synchronize and replicate all of the files of the boot partition and other related volumes on the replica. The virtual appliance may also adjust the replica's MBR, GRUB stage 1.5, and/or GRUB stage 2 code. [0055] In other examples, the master system may replicate its own hard disk to a virtual appliance. The virtual appliance may format the replica image and modify the boot configuration after replication is complete. [0056] In certain embodiments, if the file system of the boot partition is changed between the master and replica disk image, a virtual appliance may copy boot loaders corresponding to the new file system to the corresponding disk logical block address of the replica. For example, a virtual appliance may copy a GRUB stage 1.5 boot loader corresponding to the new file system format to the correct logical block address on the replica disk so that the MBR can load it correctly. [0057] In certain embodiments, further adjustments may be required to ensure the boot loader is loaded correctly. The virtual appliance may adjust the replica image accordingly. [0058] In certain embodiments, if the master system has a GRUB stage 1.5 boot loader, but, due to user configuration choices or other circumstances, the replica does not, the virtual appliance does not copy the GRUB stage 1.5 to the replica disk image. Instead, fields in the GRUB stage 2 boot loader are modified to enable it to load itself. [0059] In certain embodiments, modifications to the boot configuration of the replica image may be accomplished using GRUB commands. In certain embodiments, modifications are made using software. [0060] In certain embodiments, the teachings of the present disclosure enable one of ordinary skill in the art to rebuild boot loaders for Linux P2V, V2P and P2P while making modifications to the disk image using, for example, driver injection. [0061] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various aspects of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. [0062] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. [0063] The corresponding structures, materials, acts, and equivalents of any means or step plus function elements in the claims below are intended to include any disclosed structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The aspects of the disclosure herein were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure with various modifications as are suited to the particular use contemplated.	A method includes identifying a first boot configuration type for a disk image. The disk image includes a master boot record and a disk partition. The disk partition comprises a volume boot record. The master boot record comprises first instructions for loading an operating system, and the volume boot record comprises second instructions for loading the operating system. The method further includes receiving an input indicative of a second boot configuration type. The method also includes modifying the disk image to use the second boot configuration type to load the operating system by modifying the first instructions and the second instructions.	6
This application is a Continuation of application Ser. No. 08/221,257, filed on Mar. 31, 1994, now abandoned. BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to a compound useful as a novel recording material for optical discs and a near infrared-absorbing agent which can play an important role in optoelectronics fields of information recording, display sensors, protective spectacles and the like; an optical recording medium such as an optical disc or an optical card in which the compound is contained in a recording layer; and a near infrared-absorbing agent comprising the compound. (2) Description of the Related Art Techniques for utilizing phthalocyanine dyestuffs in recording layers of recording media such as optical discs and optical cards are widely known by Japanese Patent Application Laid-open Nos. 154888/1986 (EP 18646), 197280/1986, 246091/1986, 39286/1987 (U.S. Pat. No. 4,769,307), 37991/1988 and 39388/1988, but the phthalocyanines disclosed in these publications have been insufficient as the recording media from the viewpoints of sensitivity, refractive index, recording properties and the like. A compound in which they have been improved is described in Japanese Patent Application Laid-open No. 62878/1991, but this compound is still poor in recording properties at the time of writing by a laser beam, and so it is not sufficiently practical yet. Furthermore, it is disclosed in Japanese Patent Laid-open Nos. 214388/1992 and 238150/1993 that a phthalocyanine in which fluorine is introduced into a substituent is excellent in solubility and adhesive properties to a resin, but the introduction of the fluorine group does not contribute to the improvement of the sensitivity at the time of the writing by the laser beam. The above-mentioned phthalocyanines do not have sufficient performances regarding sensitivity (a C/N ratio or an optimum recording power), reflectance, recording properties (the shape of a signal at recording) and the like. SUMMARY OF THE INVENTION An object of the present invention is to provide a dyestuff capable of forming an optical recording medium which can hold the above-mentioned performances, i.e., which has high sensitivity and high reflectance and can form a precise signal at the time of recording. The present inventors have intensively researched with the intention of achieving the above-mentioned objects, and finally, the present invention has now been completed. That is, the present invention is directed to a phthalocyanine represented by the formula (1) ##STR2## wherein each of R 1 , R 2 , R 3 and R 4 is independently an alkyl group substituted by 0 to 5 halogen atoms and having 1 to 20 carbon atoms, an alkenyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms or an alkynyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms, and at least one of R 1 , R 2 , R 3 and R 4 is substituted by the halogen atom; X is a halogen atom; each of k, l, m and n is independently a value of from 0 to 3; each of o, p, q and r is independently a value of 0, 1 or 2, and all of them are not 0 simultaneously; each sum of k and o, l and p, m and q, and n and r is independently in the range of from 0 to 4; Met is two hydrogen atoms, a divalent metal atom, a trivalent mono-substituted metal atom, a tetravalent di-substituted metal atom or an oxy-metal atom, and the present invention is also directed to an optical recording medium formed by adding the above-mentioned phthalocyanine to a recording layer. The phthalocyanine of the present invention has a sharp absorption at 650-900 nm and is suitable for recording materials of the optical recording media using a semiconductor laser beam. The functional mechanism of the phthalocyanine of the present invention has not been elucidated and is now under investigation, but it can be presumed that the halogen atom substituted in the alkoxy group contributes to the improvement of the sensitivity at the time of recording to effectively reduce an error of a formed signal. That is, according to the phthalocyanine of the present invention, the decomposition of the dyestuff by the laser beam radiation takes place smoothly at the time of the optical recording with the reduced damage of the substrate giving a highly sensitive and accurate recording. In addition, in the case of the medium having a reflective layer, the adhesive properties of the reflective layer to a recording layer can be improved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail. A phthalocyanine of the present invention is characterized in that the α-position of a phthalocyanine ring is substituted by an alkyl group, an alkenyl group or an alkynyl group via an oxygen atom, and this substituent has at least one halogen atom. Here, the halogen atom means chlorine, bromine or iodine, and these different kinds of halogen atoms may be present together in one molecule. Above all, bromine and iodine are particularly preferable. In an optical recording medium using the above-mentioned compound, this halogen atom permits signals to be precisely written at the time of optical recording, so that sensitivity and recording properties can be improved. In the formula (1), when each of o, p, q and r is independently 2, OR 1 s, OR 2 s, OR 3 s or OR 4 s present on one benzene ring may be the same or different. Preferably, the present invention is directed to a phthalocyanine in which each of R 1 , R 2 , R 3 and R 4 is independently an alkyl group substituted by 0 to 5 halogen atoms and having 5 to 15 carbon atoms, an alkenyl group substituted by 0 to 5 halogen atoms and having 5 to 15 carbon atoms or an alkynyl group substituted by 0 to 5 halogen atoms and having 5 to 15 carbon atoms, and at least one of R 1 , R 2 , R 3 and R 4 is substituted by the halogen atom, and each of o, p, q and r is 1; and an optical recording medium formed by adding this phthalocyanine to a recording layer. Now, a preferable embodiment of the present invention will be described in detail. Examples of the substituents represented by OR 1 , OR 2 , OR 3 and OR 4 and having no halogen atom in the formula (I) include alkoxy groups having 1 to 20 carbon atoms, alkenyloxy groups having 2 to 20 carbon atoms and alkynyloxy groups having 2 to 20 carbon atoms. Typical examples of these substituents include methoxy, ethoxy, propoxy, butyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy, pentadecyloxy, hexadecyloxy, heptadecyloxy, octadecyloxy, nonadecyloxy, icosyloxy, vinyloxy, propenyloxy, butenyloxy, pentenyloxy, hexenyloxy, heptenyloxy, octenyloxy, nonenyloxy, decenyloxy, undecenyloxy, dodecenyloxy, tridecenyloxy, tetradecenyloxy, pentadecenyloxy, hexadecenyloxy, heptadecenyloxy, octadecenyloxy, nonadecenyloxy, icosenyloxy, ethynyloxy, propynyloxy, butynyloxy, pentynyloxy, hexynyloxy, heptynyloxy, octynyloxy, nonynyloxy, decynyloxy, undecynyloxy, dodecynyloxy, tridecynyloxy, tetradecynyloxy, pentadecynyloxy, hexadecynyloxy, heptadecynyloxy, octadecynyloxy, nonadecynyloxy and icosynyloxy. Above all, particularly preferable are groups which have a large steric hindrance and can easily project in a vertical direction of the phthalocyanine ring, and examples of such groups include branched alkoxy groups, alkenyloxy groups and alkynyloxy having 5 to 15 carbon atoms. Typical examples of such groups include 2-methylbutane-1-oxy, 3-methylbutane-1-oxy, 4-methylpentane-3-oxy, 4-methylpentane-2-oxy, 2-methylpentane-3-oxy, 3-methylpentane-2-oxy, 4-methylpentane-2-oxy, 3-methylpentane-3-oxy, 2-methylpentane-2-oxy, 2-methylpentane-3-oxy, 2,3-dimethylbutane-2-oxy, 4-methylhexane-2-oxy, 5-methylhexane-2-oxy, 5-methylhexane-3-oxy, 2,4-dimethylpentane-3-oxy, 2-methylhexane-3-oxy, 2-methyl-5-butylhexane-3-oxy, 3-methylhexane-2-oxy, 2,5-dimethylhexane-3-oxy, 6-methylheptane-2-oxy, 2-methylheptane-3-oxy, 2,2-dimethylheptane-3-oxy, 5-methylheptane-4-oxy, 6-methylheptane-3-oxy, 4-methylheptane-3-oxy, 3,5-dimethylheptane-4-oxy, 2,5-dimethylheptane-4-oxy, 2,4-dimethylheptane-1-oxy, 2,5-dimethyl-5-hexene-3-oxy and 2,5-dimethyl-1-hexene-3-oxy. Typical examples of alkoxy groups having 1 to 20 carbon atoms, alkenyloxy groups having 2 to 20 carbon atoms and alkynyloxy groups having 2 to 20 carbon atoms which have the halogen atoms include chloromethyloxy, bromomethyloxy, 2-chloroethyl-1-oxy, 2-bromoethyl-1-oxy, 2-iodoethyl-1-oxy, 2-chloropropyl-1-oxy, 1-chloropropyl-2-oxy, 2-bromopropyl-1-oxy, 1-bromopropyl-2-oxy, 2-iodopropyl-1-oxy, 1-iodopropyl-2-oxy, 2,3-dichloropropyl-1-oxy, 2,3-dibromopropyl-1-oxy, 2,3-diiodopropyl-1-oxy, 3-chlorobutyl-1-oxy, 3-bromobutyl-1-oxy, 3-iodobutyl-1-oxy, 3,4-dichloro-2-butyloxy, 3,4-dibromo-2-butyloxy, 3,4-diiodo-2-butyloxy, 1-iodopentane-3-oxy, 2-iodopentane-3-oxy, 1-chloropentane-3-oxy, 2-chloropentane-3-oxy, 1-bromopentane-3-oxy, 2-bromopentane-3-oxy, 1,2-diiodopentane-3-oxy, 1,2-dibromopentane-3-oxy, 5-iodohexane-2-oxy, 6-iodohexane-2-oxy, 6-chlorohexane-2-oxy, 1,2-dichloropentane-3-oxy, 1,2-dibromopentane-3-oxy, 5-iodohexane-2-oxy, 6-iodohexane-2-oxy, 5-chlorohexane-2-oxy, 6-chlorohexane-2-oxy, 5-bromohexane-2-oxy, 6-bromohexane-2-oxy, 5,6-diiodohexane-2-oxy, 5,6-dichlorohexane-2-oxy, 5,6-dibromohexane-2-oxy, 1-iodohexane-3-oxy, 2-iodohexane-3-oxy, 1-chlorohexane-3-oxy, 2-chlorohexane-3-oxy, 1-bromohexane-3-oxy, 2-bromohexane-3-oxy, 1,2-diiodohexane-3-oxy, 1,2-dichlorohexane-3-oxy, 1,2-dibromohexane-3-oxy, 5-iodohexane-1-oxy, 6-iodohexane-1-oxy, 5-chlorohexane-1-oxy, 6-chlorohexane-1-oxy, 5-bromohexane-1-oxy, 6-bromohexane-1-oxy, 5,6-diiodohexane-1-oxy, 5,6-dichlorohexane-1-oxy, 5,6-dibromohexane-1-oxy, 3-iodohexane-1-oxy, 4-iodohexane-1-oxy, 3-chlorohexane-1-oxy, 4-chlorohexane-1-oxy, 3-bromohexane-1-oxy, 4-bromohexane-1-oxy, 3,4-diiodohexane-1-oxy, 3,4-dichlorohexane-1-oxy, 3,4-dibromohexane-1-oxy, 5-iodohexane-1-oxy, 5-chlorohexane-1-oxy, 5-bromohexane-1-oxy, 4,5-diiodohexane-1-oxy, 4,5-dichlorohexane-1-oxy, 4,5-dibromohexane-1-oxy, 1-iodoheptane-4-oxy, 1-chloroheptane-4-oxy, 1-bromoheptane-4-oxy, 2-iodoheptane-4-oxy, 2-chloroheptane-4-oxy, 2-bromoheptane-4-oxy, 1,2-diiodoheptane-4-oxy, 1,2-dichloroheptane-4-oxy, 1,2-dibromoheptane-4-oxy, 3-iodoheptane-4-oxy, 3-chloroheptane-4-oxy, 3-bromoheptane-4-oxy, 2,3-diiodoheptane-4-oxy, 2,3-dichloroheptane-4-oxy, 2,3-dibromoheptane-4-oxy, 1-iodoheptane-3-oxy, 1-chloroheptane-3-oxy, 1-bromoheptane-3-oxy, 2-iodoheptane-3-oxy, 2-chloroheptane-3-oxy, 2-bromoheptane-3-oxy, 1,2-diiodoheptane-3-oxy, 1,2-dichlroheptane-3-oxy, 1,2-dibromoheptane-3-oxy, 1-iodooctane-3-oxy, 1-chlorooctane-3-oxy, 1-bromooctane-3-oxy, 2-iodooctane-3-oxy, 2-chlorooctane-3-oxy, 2-bromooctane-3-oxy, 1,2-diiodooctane-3-oxy, 1,2-dichlorooctane-3-oxy, 1,2-dibromooctane-3-oxy, 1-iodooctane-4-oxy, 1-chlorooctane-4-oxy, 1-bromooctane-4-oxy, 2-iodooctane-4-oxy, 2-chlorooctane-4-oxy, 2-bromooctane-4-oxy, 1,2-diiodooctane-4-oxy, 1,2-dichlorooctane-4-oxy, 1,2-dibromooctane-4-oxy, 3-iodooctane-4-oxy, 3-chlorooctane-4-oxy, 3-bromooctane-4-oxy, 2,3-diiodooctane-4-oxy, 2,3-dichlorooctane-4-oxy, 2,3-dibromooctane-4-oxy, 1-iodononane-3-oxy, 2-iodononane-3-oxy, 1-chlorononane-3-oxy, 2-chlorononane-3-oxy, 1-bromononane-3-oxy, 2-bromononane-3-oxy, 1,2-diiodononane-3-oxy, 1,2-dichlorononane-3-oxy, 1,2-dibromononane-3-oxy, 3-iodo-2-methylbutane-1-oxy, 3-chloro-2-methylbutane-1-oxy, 3-bromo-2-methylbutane-1-oxy, 4-iodo-2-methylbutane-1-oxy, 4-chloro-2-methylbutane-1-oxy, 4-bromo-2-methylbutane-1-oxy, 3,4-diiodo-2-methylbutane-1-oxy, 3,4-dichloro-2-methylbutane-1-oxy, 3,4-dibromo-2-methylbutane-1-oxy, 2-iodo-3-methylbutane-1-oxy, 2-chloro-3-methylbutane-1-oxy, 2-bromo-3-methylbutane-1-oxy, 2,3-dibromo-3-methylbutane-1-oxy, 4-iodo-3-methylbutane-1-oxy, 4-chloro-3-methylbutane-1-oxy, 4-bromo-3-methylbutane-1-oxy, 3-methyl-3,4-dibromobutane-1-oxy, 1-iodo-4-methylpentane-3-oxy, 2-iodo-4-methylpentane-3-oxy, 1-chloro-4-methylpentane-3-oxy, 2-chloro-4-methylpentane-3-oxy, 1-bromo-4-methylpentane-3-oxy, 2-bromo-4-methylpentane-3-oxy, 1,2-diiodo-4-methylpentane-3-oxy, 1,2-dichloro-4-methylpentane-3-oxy, 1,2-dibromo-4-methylpentane-3-oxy, 3-iodo-4-methylpentane-2-oxy, 3-chloro-4-methylpentane-2-oxy, 3-bromo-4-methylpentane-2-oxy, 3,4-dibromo-4-methylpentane-2-oxy, 1-iodo-2-methylpentane-3-oxy, 1-chloro-2-methylpentane-3-oxy, 1-bromo-2-methylpentane-3-oxy, 1,2-dibromo-2-methylpentane-3-oxy, 4-iodo-3-methylpentane-2-oxy, 5-iodo-3-methylpentane-2-oxy, 4-chloro-3-methylpentane-2-oxy, 5-chloro-3-methylpentane-2-oxy, 4-dibromo-3-methylpentane-2-oxy, 5-bromo-3-methylpentane-2-oxy, 4,5-diiodo-3-methylpentane-2-oxy, 4,5-dichloro-3-methylpentane-2-oxy, 4,5-dibromo-3-methylpentane-2-oxy, 5-iodo-4-methylpentane-2-oxy, 5-bromo-4-methylpentane-2-oxy, 4,5-dibromo-4-methylpentane-2-oxy, 1-iodo-3-methylpentane-3-oxy, 2-iodo-3-methylpentane-3-oxy, 1-chloro-3-methylpentane-3-oxy, 2-chloro-3-methylpentane-3-oxy, 1-bromo-3-methylpentane-3-oxy, 2-bromo-3-methylpentane-3-oxy, 1,2-diiodo-3-methylpentane-3-oxy, 1,2-dicholoro-3-methylpentane-3-oxy, 1,2-dibromo-3-methylpentane-3-oxy, 4-iodo-2-methylpentane-2-oxy, 5-iodo-2-methylpentane-2-oxy, 4-chloro-2-methylpentane-2-oxy, 5-chloro-2-methylpentane-2-oxy, 4-bromo-2-methylpentane-2-oxy, 5-bromo-2-methylpentane-2-oxy, 4,5-diiodo-2-methylpentane-3-oxy, 4,5-dichloro-2-methylpentane-3-oxy, 4,5-dibromo-2-methylpentane-3-oxy, 2,3-dimethyl-4-iodobutane-2-oxy, 2,3-dimethyl-4-chlorobutane-2-oxy, 2,3-dimethyl-4-bromobutane-2-oxy, 2,3-dimethyl-3,4-dibromobutane-2-oxy, 4-methyl-5-iodohexane-2-oxy, 4-methyl-5-bromohexane-2-oxy, 4-methyl-4,5-dibromohexane-2-oxy, 5-methyl-6-iodohexane-2-oxy, 5-methyl-6-chlorohexane-2-oxy, 5-methyl-6-bromohexane-2-oxy, 5-methyl-5,6-dibromohexane-2-oxy, 5-methyl-6-iodohexane-3-oxy, 5-methyl-6-chlorohexane-3-oxy, 5-methyl-6-bromohexane-3-oxy, 5-methyl-5,6-dibromohexane-3-oxy, 1-iodo-2,4-dimethylpentane-3-oxy, 1-chloro-2,4-dimethylpentane-3-oxy, 1-bromo-2,4-dimethylpentane-3-oxy, 1,2-dibromo-2,4-dimethylpentane-3-oxy, 2-methyl-5-iodohexane-3-oxy, 2-methyl-6-iodohexane-3-oxy, 2-methyl-5,6-diiodohexane-3-oxy, 2-methyl-5-chlorohexane-3-oxy, 2-methyl-6-chlorohexane-3-oxy, 2-methyl-5,6-dichlorohexane-3-oxy, 2-methyl-5-bromohexane-3-oxy, 2-methyl-6-bromohexane-3-oxy, 2-methyl-5,6-dibromohexane-3-oxy, 2-methyl-4-iodohexane-3-oxy, 2-methyl-4,5-diiodohexane-3-oxy, 2-methyl-4-chlorohexane-3-oxy, 2-methyl-4,5-dichlorohexane-3-oxy, 2-methyl-4-bromohexane-3-oxy, 2-methyl-4,5-dibromohexane-3-oxy, 3-methyl-4-iodohexane-2-oxy, 3-methyl-4-chlorohexane-2-oxy, 3-methyl-4-bromohexane-2-oxy, 3-methyl-3,4-dibromohexane-2-oxy, 2,5-dimethyl-6-iodohexane-3-oxy, 2,5-dimethyl-6-chlorohexane-3-oxy, 2,5-dimethyl-6-bromohexane-3-oxy, 2,5-dimethyl-6,6-dibromohexane-3-oxy, 1,6-diiodo-2,5-dimethylhexane-3-oxy, 1,6-dichloro-2,5-dimethylhexane-3-oxy, 1,2-dibromo-2,5-dimethyl-5-hexane-3-oxy, 1,2-dichloro-2,5-dimethyl-5-hexene-3-oxy, 1,6-dibromo-2,5-dimethylhexane-3-oxy, 5,6-dibromo-2,5-dimethyl-1-hexene-3-oxy, 5,6-dichloro-2,5-dimethyl-1-hexene-3-oxy, 1,2,5,6-tetrabromo-2,5-dimethylhexane-3-oxy, 1,2,5,6-tetrachloro-2,5-dimethylhexane-3-oxy, 5-iodo-6-methylheptane-2-oxy, 5-bromo-6-methylheptane-2-oxy, 5-chloro-6-methylheptane-2-oxy, 5,6-dibromo-6-methylheptane-2-oxy, 5,6-dichloro-6-methylheptane-2-oxy, 1-iodo-2-methylheptane-3-oxy, 1-chloro-2-methylheptane-3-oxy, 1-bromo-2-methylheptane-3-oxy, 1,2-dibromo-2-methylheptane-3-oxy, 1,2-dichloro-2-methylheptane-3-oxy, 2,2-dimethyl-5-iodoheptane-3-oxy, 2,2-dimethyl-6-iodoheptane-3-oxy, 2,2-dimethyl-5-chloroheptane-3-oxy, 2,2-dimethyl-6-chloroheptane-3-oxy, 2,2-dimethyl-5-bromoheptane-3-oxy, 2,2-dimethyl-6-bromoheptane-3-oxy, 2,2-dimethyl-5,6-diiodo-3-oxy, 2,2-dimethyl-5,6-dichloroheptane-3-oxy, 2,2-dimethyl-5,6-dibromoheptane-3-oxy, 1-iodo-5-methylheptane-4-oxy, 2-iodo-5-methylheptane-4-oxy, 1,2-diiodo-5-methylheptane-4-oxy, 1-chloro-5-methylheptane-4-oxy, 2-chloro-5-methylheptane-4-oxy, 1,2-dichloro-5-methylheptane-4-oxy, 1-bromo-5-methylheptane-4-oxy, 2-bromo-5-methylheptane-4-oxy, 1,2-dibromo-5-methylheptane-4-oxy, 6-methyl-7-iodoheptane-3-oxy, 6-methyl-7-chloroheptane-3-oxy, 6-methyl-7-bromoheptane-3-oxy, 6-methyl-6,7-dichloroheptane-3-oxy, 6-methyl-6,7-dibromoheptane-3-oxy, 1,2-diiodo-3,5-dimethylheptane-4-oxy, 1,6-diiodo-3,5-dimethylheptane-4-oxy, 1,7-diiodo-3,5-dimethylheptane-4-oxy, 2,6-diiodo-3,5-dimethylheptane-4-oxy, 6-iodo-3,5-dimethyl-1-heptene-4-oxy, 7-iodo-3,5-dimethyl-1-heptene-4-oxy, 6,7-diiodo-3,5-dimethyl-1-heptene-4-oxy, 1,2-dibromo-3,5-dimethylheptane-4-oxy, 1,6-dibromo-3,5-dimethylheptane-4-oxy, 1,7-dibromo-3,5-dimethylheptane-4-oxy, 2,6-dibromo-3,5-dimethylheptane-4-oxy, 6-bromo-3,5-dimethyl-1-heptene-4-oxy, 7-bromo-3,5-dimethyl-1-heptene-4-oxy, 6,7-dibromo-3,5-dimethyl-1-heptene-4-oxy, 1,2-dichloro-3,5-dimethylheptane-4-oxy, 1,6-dichloro-3,5-dimethylheptane-4-oxy, 1,7-dichloro-3,5-dimethylheptane-4-oxy, 2,6-dichloro-3,5-dimethylheptane-4-oxy, 6-chloro-3,5-dimethyl-1-heptene-4-oxy, 7-chloro-3,5-dimethyl-1-heptene-4-oxy, 6,7-dichloro-3,5-dimethyl-1-heptene-4-oxy, 1,2,6,7-tetrachloro-3,5-dimethylheptane-4-oxy, 1-iodo-2,5-dimethylheptane-4-oxy, 1-bromo-2,5-dimethylheptane-4-oxy, 2-bromo-2,5-dimethylheptane-4-oxy, 1,2-dibromo-2,5-dimethylheptane-4-oxy, 1-chloro-2,5-dimethylheptane-4-oxy, 2-chloro-2,5-dimethylheptane-4-oxy, 1,2-dichloro-2,5-dimethylheptane-4-oxy, 2,4-dimethyl-2-iodoheptane-1-oxy, 2,4-dimethyl-3-iodoheptane-1-oxy, 2,4-dimethyl-2,3-diiodoheptane-1-oxy, 2,4-dimethyl-2,6-diiodoheptane-1-oxy, 2,4-dimethyl-2,7-diiodoheptane-1-oxy, 2,4-dimethyl-3,6-diiodoheptane-1-oxy, 2,4-dimethyl-3,7-diiodoheptane-1-oxy, 2,4-dimethyl-6,7-diiodoheptane-1-oxy, 2,4-dimethyl-2-iodo-6-heptene-1-oxy, 2,4-dimethyl-3-iodo-6-heptene-1-oxy, 2,4-dimethyl-2,3-diiodo-6-heptene-1-oxy, 2,4-dimethyl-6-iodo-2-heptene-1-oxy, 2,4-dimethyl-7-iodo-2-heptene-1-oxy, 2,4-dimethyl-6,7-diiodo-2-heptene-1-oxy, 2,4-dimethyl-2-bromoheptane-1-oxy, 2,4-dimethyl-3-bromoheptane-1-oxy, 2,4-dimethyl-6-bromoheptane-1-oxy, 2,4-dimethyl-7-bromoheptane-1-oxy, 2,4-dimethyl-2,3-dibromoheptane-1-oxy, 2,4-dimethyl-3,6-dibromoheptane-1-oxy, 2,4-dimethyl-3,7-dibromoheptane-1-oxy, 2,4-dimethyl-6,7-dibromoheptane-1-oxy, 2,4-dimethyl-2-bromo-6-heptene-1-oxy, 2,4-dimethyl-3-bromo-6-heptene-1-oxy, 2,4-dimethyl-2,3-dibromo-6-heptene-1-oxy, 2,4-dimethyl-6-bromo-2-heptene-1-oxy, 2,4-dimethyl-7-bromo-2-heptene-1-oxy, 2,4-dimethyl-6,7-dibromo-2-heptene-1-oxy, 2,4-dimethyl-2,3,6,7-tetrachloro-2-heptene-1-oxy, 2,4-dimethyl-2-chloroheptane-1-oxy, 2,4-dimethyl-3-chloroheptane-1-oxy, 2,4-dimethyl-6-chloroheptane-1-oxy, 2,4-dimethyl-7-chloroheptane-1-oxy, 2,4-dimethyl-2,3-dichloroheptane-1-oxy, 2,4-dimethyl-3,6-dichloroheptane-1-oxy, 2,4-dimethyl-3,7-dichloroheptane-1-oxy, 2,4-dimethyl-6,7-dichloroheptane-1-oxy, 2,4-dimethyl-2-chloro-6-heptene-1-oxy, 2,4-dimethyl-3-chloro-6-heptene-1-oxy, 2,4-dimethyl-2,3-dichloro-6-heptene-1-oxy, 2,4-dimethyl-6-chloro-2-heptene-1-oxy, 2,4-dimethyl-7-chloro-2-heptene-1-oxy and 2,4-dimethyl-6,7-dichloro-2-heptene-1-oxy. Among the substituents having the halogen atoms, particularly preferable examples are groups which has a large steric hindrance and can easily project in a vertical direction of the phthalocyanine ring, and typical examples of such groups include 2,5-dimethyl-5-bromohexane-3-oxy, 2,5-dimethyl-6-bromohexane-3-oxy, 2,5-dimethyl-5,6-dibromohexane-3-oxy, 1-bromo-2,4-dimethylpentane-3-oxy, 2-bromo-2,4-dimethylpentane-3-oxy, 1,2-dibromo-2,4-dimethylpentane-3-oxy, 1-bromo-2,5-dimethylhexane-3-oxy, 2-bromo-2,5-dimethylhexane-3-oxy, 1,2-dibromo-2,5-dimethylhexane-3-oxy, 1-bromo-2,5-dimethyl-5-hexene-3-oxy, 2-bromo-2,5-dimethyl-5-hexene-3-oxy, 1,2-dibromo-2,5-dimethyl-5-hexene-3-oxy, 2,5-dimethyl-5-bromo-1-hexene-3-oxy, 2,5-dimethyl-6-bromo-1-hexene-3-oxy, 2,5-dimethyl-5,6-dibromo-1-hexene-3-oxy, 1-bromo-3,5-dimethylheptane-4-oxy, 2-bromo-3,5-dimethylheptane-4-oxy, 1,2-dibromo-3,5-dimethylheptane-4-oxy, 1,6-dibromo-3,5-dimethylheptane-4-oxy, 1,7-dibromo-3,5-dimethylheptane-4-oxy, 4-methyl-5-bromopentane-2-oxy, 6-bromo-3,5-dimethyl-1-heptene-4-oxy, 7-bromo-3,5-dimethyl-1-heptene-4-oxy, 6,7-dibromo-3,5-dimethyl-1-heptene-4-oxy, 4-methyl-4-bromopentane-2-oxy, 4-methyl-5-bromopentane-2-oxy, 4-methyl-4,5-dibromopentane-2-oxy, 1-bromo-4-methylpentane-2-oxy, 2-bromo-4-methylpentane-2-oxy, 1,2-dibromo-4-methylpentane-2-oxy, 1-bromo-2-methylpentane-3-oxy, 2-bromo-2-methylpentane-3-oxy, 1,2-dibromo-2-methylpentane-3-oxy, 5-methyl-5-bromopentane-3-oxy, 5-methyl-6-bromopentane-3-oxy, 5-methyl-5,6-dibromopentane-3-oxy, 2,5-dimethyl-5-chlorohexane-3-oxy, 2,5-dimethyl-6-chlorohexane-3-oxy, 2,5-dimethyl-5,6-dichlorohexane-3-oxy, 1-chloro-2,4-dimethylpentane-3-oxy, 2-chloro-2,4-dimethylpentane-3-oxy, 1,2-dichloro-2,4-dimethylpentane-3-oxy, 1-chloro-2,5-dimethylhexane-3-oxy, 2-chloro-2,5-dimethylhexane-3-oxy, 1,2-dichloro-2,5-dimethylhexane-3-oxy, 1-chloro-2,5-dimethyl-5-hexene-3-oxy, 2-chloro-2,5-dimethyl-5-hexene-3-oxy, 1,2-dichloro-2,5-dimethyl-5-hexene-3-oxy, 2,5-dimethyl-5-chloro-1-hexene-3-oxy, 2,5-dimethyl-6-chloro-1-hexene-3-oxy, 2,5-dimethyl-5,6-dichloro-1-hexene-3-oxy, 1-chloro-3,5-dimethylheptane-4-oxy, 2-chloro-3,5-dimethylheptane-4-oxy, 1,2-dichloro-3,5-dimethylheptane-4-oxy, 1,6-dichloro-3,5-dimethylheptane-4-oxy, 1,7-dichloro-3,5-dimethylheptane-4-oxy, 4-methyl-5-chloropentane-2-oxy, 6-chloro-3,5-dimethyl-1-heptene-4-oxy, 7-chloro-3,5-dimethyl-1-heptene-4-oxy, 6,7-dichloro-3,5-dimethyl-1-heptene-4-oxy, 4-methyl-4-chloropentane-2-oxy, 4-methyl-5-chloropentane-2-oxy, 4-methyl-4,5-dichloropentane-2-oxy, 1-chloro-4-methylpentane-2-oxy, 2-chloro-4-methylpentane-2-oxy, 1,2-dichloro-4-methylpentane-2-oxy, 1-chloro-2-methylpentane-3-oxy, 2-chloro-2-methylpentane-3-oxy, 1,2-dichloro-2-methylpentane-3-oxy, 5-methyl-5-chloropentane-3-oxy, 5-methyl-6-chloropentane-3-oxy and 5-methyl-5,6-dichloropentane-3-oxy. Examples of a divalent metal represented by Met in the formula (I) include Cu, Zn, Fe, Co, Ni, Ru, Rh, Pd, Pt, Pb, Mn and Mg, and examples of a mono-substituted trivalent metal include Al--Cl, Al--Br, In--Cl, In--Br, Ga--Cl and Ga--Br. Furthermore, examples of a di-substituted tetravalent metal include SiCl 2 , SiBr 2 , SiF 2 , SnCl 2 , SnBr 2 , SnF 2 , GeCl 2 , GeBr 2 , GeF 2 , Si(OH) 2 , Sn(OH) 2 , Ge(OH) 2 , Si(OY) 2 , Sn(OY) 2 , Ge(OY) 2 , Si(SY) 2 , Sn(SY) 2 and Ge(SY) 2 (wherein Y is an alkyl group, a phenyl group, a naphthyl group or its derivative), and examples of an oxymetal include VO, MnO and TiO. Above all, Cu, Ni, Co, Pd, Pt, Mg and VO are particularly preferable. A method of synthesizing a phthalocyanine compound represented by the formula (1) comprises thermally reacting 1 to 4 kinds of compounds (the undermentioned s of at least one of these compounds is not 0) represented by the formula (2) ##STR3## wherein R is an unsaturated hydrocarbon group, s is 0, 1 or 2, X is a halogen atom, and t is 0.1 or 2, with a metallic derivative in an alcohol in the presence of 1,8-diazabicyclo[5,4,0]-7-undecene (DBU), or it comprises thermally reacting the compound of the above-mentioned formula (2) with a metallic compound in a high-boiling solvent such as chloronaphthalene, bromonaphthalene or trichlorobenzene to synthesize a phthalocyanine having an unsaturated hydrocarbonoxy group, and then reacting this phthalocyanine with a halogenating agent such as thionyl chloride, sulfuryl chloride, hydrobromic acid, bromine, iodine or iodine monochloride giving halogen addition to the unsaturated hydrocarbon group (Rs). Alternatively, the phthalocyanine compound can also be produced by similarly reacting, as an intermediate, a diiminoisoindoline represented by the formula (3) obtained by reacting the compound of the formula (2) with ammonia in the presence of a catalyst comprising sodium methylate in an alcohol: ##STR4## wherein R, s, X and t are as defined above. In the present invention, the phthalocyanine compound represented by the formula (1), which contains the alkoxy group not substituted by the halogen atom, can also be obtained by mixing a compound of the formula (2) or (3) where R is a saturated hydrocarbon group with a compound of the formula (2) or (3) to synthesize a phthalocyanine compound in which partial Rs of the OR groups of the phthalocyanine are saturated hydrocarbon groups, and then reacting the thus synthesized compound with the above-mentioned halogenating agent. The compound represented by the formula (2) can be, for example, synthesized by a process of the following formula (4): ##STR5## (3-)nitrophthalonitrile which is a starting material was available from Tokyo Chemicals Co., Ltd. The compound having the formula (2) was synthesized from (3-)nitrophthalonitrile in accordance with a process described in Nouveau Journal De Chimie, Vol. 6, p. 635-658, 1982. That is, an alcohol was reacted with sodium hydride to form sodium alkoxide, and this alkoxide was then reacted with (3-)nitrophthalonitrile at a temperature of from 0° to 100° C. to obtain the desired compound of the formula (2). As a method for preparing an optical recording medium by the use of the phthalocyanine compound of the present invention, there is a process of applying or depositing one or two layers of 1 to 3 kinds of compounds containing the phthalocyanine of the present invention onto a transparent substrate. In the case of the applying process, a binder resin and the phthalocyanine of the present invention are dissolved in a solvent so that the content of the binder resin may be 20% by weight, preferably 0% and that of the phthalocyanine of the present invention may be in the range of from 0.05 to 20% by weight, preferably from 0.5 to 20% by weight, and the solution was then applied onto the substrate by means of a spin coater. On the other hand, in the case of the depositing process, the solution is deposited on the substrate at 100°-300° C. under 10 -5 to 10 -7 Torr. The thickness of the recording layer containing the phthalocyanine compound is about 100 Å-10,000 Å. As the substrate, any of optically transparent resins can be used. Example of such resins include an acrylic resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin, polycarbonate resin, polyolefin copolymer resin, vinyl chloride copolymer resin, vinylidene chloride copolymer resin and styrene copolymer resin. The substrate may be subjected to a surface treatment with a thermosetting resin or an ultraviolet-setting resin. In the case that optical recording media (optical discs, optical cards and the like) are manufactured, it is preferred from the viewpoints of cost and handling properties for a user that the polyacrylate substrate or the polycarbonate substrate is used and the application is done by a spin coating method. A solvent for use in the spin coating method should be selected in consideration of solvent resistance properties of the substrate, and suitable examples of such a solvent include halogenated hydrocarbons (e.g., dichloromethane, chloroform, carbon tetrachloride, tetrachloroethylene and dichlorodifluoroethane), ethers (e.g., tetrahydrofuran, diethyl ether, diisopropyl ether and dioxane), alcohols (e.g., methanol, ethanol and propanol), cellosolves (e.g., methyl cellosolve and ethyl cellosolve), and hydrocarbons (e.g., hexane, octane, benzene, toluene and xylene). The formation of the recording medium can be achieved by covering the substrate with a recording layer as described above, by integrally sticking two substrates having recording layers with the interposition of an air gap, or by applying a reflective layer (aluminum or gold) on a recording layer, and then laminating a protective layer of a thermosetting (photo-setting) resin thereon. The phthalocyanine compound of the present invention (the content is 0,001% to 100%) can be also used as a variety of potential infrared absorbing agents. Next, the present invention will be described in detail in reference to examples, but the scope of the present invention should not be limited to these examples. EXAMPLE 1 9.6 g (0.24 mol) of 60% sodium hydride and 150 ml of N,N-dimethylformamide were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then stirred under the feed of nitrogen. Afterward, 32 g (0.25 mol) of 2,5-dimethyl-5-hexene-3-ol was added dropwise thereto at 20°-30° C. over 1 hour, and the solution was then stirred at the same temperature for 3 hours to prepare a sodium alcoholate solution. Next, 34.6 g (0.2 mol) of 3-nitrophthalonitrile and 150 ml of N,N-dimethylformamide were placed in a container equipped with a stirrer, and the above-mentioned sodium alcoholate solution was then added dropwise at 0° C. or less over 5 hours. After completion of the addition, the temperature of the solution was raised up to a level of 20°-30° C., and the solution was then stirred for 2 hours to bring reaction to an end. The thus obtained reaction solution was poured into 3 l of water and then stirred for 30 minutes, and 500 ml of toluene were added. After stirring for 30 minutes, the solution was allowed to stand to separate a toluene layer. After toluene was distilled off under reduced pressure, recrystallization was carried out from 500 ml of n-hexane to obtain 43.7 g of 3-(2,5-dimethyl-5-hexene-3-oxy)phthalonitrile (yield=86.0%). ______________________________________Elemental analysis: C.sub.16 H.sub.18 N.sub.2 O C H N______________________________________Calcd. (%) 75.59 7.09 11.02Found (%) 75.08 7.11 11.25______________________________________ Next, 25.4 g (0.1 mol) of the thus obtained 3-(2,5-dimethyl-5-hexene-3-oxy)phthalonitrile, 15.2 g (0.1 mol) of DBU and 120 g of n-amyl alcohol were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then heated up to 110° C. under a nitrogen atmosphere. Moreover, 5.3 g (0.03 mol) of palladium chloride were added at the same temperature, and reaction was carried out at 120° C. for 10 hours. After cooling, insolubles were removed by filtration, and the resulting filtrate was concentrated under reduced pressure to collect the solvent. Afterward, column purification (300 g of silica gel, toluene development) was made to obtain deep green crystals of a phthalocyanine palladium compound having unsaturated hydrocarbonoxy groups. Its yield was 17.4 g (yield ratio=62.1%). Maximum absorption wavelength (λ max ), gram absorptivity coefficient (ε g ) and the results of elemental analysis were as follows: λ.sub.max =688.5 nm ε.sub.g =1.9×10.sup.5 g.sup.-1 ______________________________________Elemental analysis: C.sub.64 H.sub.72 N.sub.8 O.sub.4 Pd C H N______________________________________Calcd. (%) 68.42 6.41 9.98Found (%) 68.19 6.52 9.63______________________________________ 5 g (4.50 mmols) of palladium tetra-α-(2,5-dimethyl-5-hexene-3-oxy)phthalocyanine were dissolved in 30 g of 1,1,2-trichloroethane, and 10 g of water were then added thereto. Next, a mixed solution of 5.4 g (33.79 mmols) of bromine and 6 g of 1,1,2-trichloroethane was added dropwise to the solution at 50°-55° C., and reaction was carried out at 55°-60° C. for 1 hour. Afterward, 5 g of a 15% aqueous sodium hydrogensulfite solution were added to the solution to wash it. The resulting organic layer was added dropwise to 80 g of methanol, and the precipitated crystals were collected by filtration to obtain 8.0 g of a brominated phthalocyanine. It was elucidated by NMR that bromine atoms were substituted on all the double bonds of side chains, and it was also elucidated by elemental analysis that 11.5 bromine atoms were substituted. Hence, it is apparent that the ring was substituted by 3.5 bromine atoms. ______________________________________Elemental analysis: C.sub.64 H.sub.68.5 N.sub.8 O.sub.4 Br.sub.11.5 Pd C H N Br______________________________________Found (%) 37.72 3.41 5.49 44.96Calcd. (%) 37.69 3.39 5.52 45.07______________________________________ λ.sub.max =708.5 nm ε.sub.g =1.3×10.sup.5 g.sup.-1 EXAMPLE 2 5 g of the brominated phthalocyanine obtained in Example 1 were dissolved in 500 ml of n-octane, and the solution was then applied onto a polycarbonate substrate by spin coating to form a recording layer of thickness of about 800 Å. Next, gold was sputtered thereon to form a reflective layer, thereby forming a CD-R medium. The reflectance of this medium was 71% (775-790 nm), and EFM signals could be written on the medium at a linear velocity of 1.3 m/sec at a power of 5.5 mW by the use of a semiconductor laser at 780 nm. At this time, an error rate was less than 10. EXAMPLE 3 5 g (4.50 mmols) of palladium tetra-α-(2,5-dimethyl-5-hexene-3-oxy)phthalocyanine synthesized in Example 1 were dissolved in 35 g of 1,1,2,2-tetrachloroethane, and the solution was then heated up to 50°-60° C. Afterward, 3.1 g (18.01 mmols) of 47% hydrobromic acid were added dropwise at the same temperature, and reaction was carried out at 60°-70° C. for 1 hour. After cooling to 20° C., the solution was washed with 10 g of a 10% aqueous sodium hydrogensulfite solution and 10 g of a 5% aqueous sodium hydrogencarbonate solution. The resulting organic layer was separated and then added dropwise to 90 g of methanol, and the precipitated crystals were collected by filtration to obtain 5.8 g of a brominated phthalocyanine. It was elucidated by elemental analysis that 4 bromine atoms were substituted, and it was also elucidated by FD-MS that all the bromine atoms were substituted on side chains. ______________________________________Elemental analysis: C.sub.64 H.sub.76 N.sub.8 O.sub.4 Br.sub.4 Pd C H N Br______________________________________Found (%) 53.25 5.32 7.66 21.91Calcd. (%) 53.11 5.29 7.74 22.08______________________________________ λ.sub.max =688.5 nm ε.sub.g =1.5×10.sup.5 g.sup.-1 EXAMPLE 4 5 g of the brominated phthalocyanine synthesized in Example 3 were dissolved in 500 ml of dibutyl ether, and the solution was then applied onto an optical card substrate made of a polycarbonate by spin coating. Next, a protective layer was then formed on the applied surface, thereby preparing an optical card. This optical card could be recorded at a linear velocity of 2 m/sec by a semiconductor laser beam of 4 mW, and a CN ratio was 63 dB. The optical card could be reproduced at a linear velocity of 2 m/sec by a laser beam of 0.8 mW, and even when the reproduction was done 10 5 times, any record did not change. EXAMPLE 5 9.6 g (0.24 mol) of 60% sodium hydride and 150 ml of N,N-dimethylformamide were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then stirred under the feed of nitrogen. Afterward, 35 g (0.25 mol) of 3,5-dimethyl-1,6-heptadiene-4-ol was added dropwise thereto at 20°-30° C. over 1 hour, and the solution was then stirred at the same temperature for 3 hours to prepare a sodium alcoholate solution. Next, 34.6 g (0.2 mol) of 3-nitrophthalonitrile and 150 ml of N,N-dimethylformamide were placed in a container equipped with a stirrer, and the above-mentioned sodium alcoholate solution was added dropwise thereto at 0° C. or less over 5 hours. After completion of the addition, the temperature of the solution was raised up to a level of 20°-30° C., and the solution was then stirred for 3 hours to bring reaction to an end. The thus obtained reaction solution was poured into 3 l of water and then stirred for 30 minutes, and 500 ml of toluene were added. After stirring for 30 minutes, the resulting toluene layer was separated. After toluene was distilled off under reduced pressure, recrystallization was carried out from 600 ml of n-hexane to obtain 44.7 g of 3-(3,5-dimethyl-1,6-heptadiene-4-oxy)phthalonitrile (yield=84.0%). ______________________________________Elemental analysis: C.sub.17 H.sub.18 N.sub.2 O C H N______________________________________Calcd. (%) 76.69 6.77 10.53Found (%) 76.52 6.91 10.38______________________________________ Next, 26.6 g (0.1 mol) of the thus obtained 3-(3,5-dimethyl-1,6-heptadiene-4-oxy)phthalonitrile, 15.2 g (0.1 mol) of DBU and 125 g of n-amyl alcohol were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then heated up to 110° C. under a nitrogen atmosphere. Moreover, 5.3 g (0.03 mol) of palladium chloride were added at the same temperature, and reaction was carried out at 120°-130° C. for 9 hours. After cooling, insolubles were removed by filtration, and the resulting filtrate was concentrated under reduced pressure to collect the solvent. Afterward, column purification (500 g of silica gel, toluene development) was made to obtain deep green crystals of a phthalocyanine palladium compound having unsaturated hydrocarbonoxy groups. Its yield was 19.0 g (yield ratio=65%). Maximum absorption wavelength (λ max ), gram absorptivity coefficient (ε g ) and the results of elemental analysis were as follows: λ.sub.max =690.0 nm ε.sub.g =1.9×10.sup.5 g.sup.-1 ______________________________________Elemental analysis: C.sub.68 H.sub.72 N.sub.8 O.sub.4 Pd C H N______________________________________Calcd. (%) 69.72 6.15 9.57Found (%) 69.81 6.05 9.62______________________________________ 10 g (8.53 mmols) of palladium tetra-α-(3,5-dimethyl-1,6-heptadiene-4-oxy)phthalocyanine were added to a mixed solution of 50 g of dichloromethane, 50 g of n-hexane and 100 g of water, and 4.8 g (30.03 mmols) of bromine were added dropwise, and reaction was carried out at 40° C. for 2 hours. After cooling to 20° C., 50 g of toluene were added, followed by separation. Successively, the resulting organic layer was washed with 100 g of a 10% aqueous sodium hydrogensulfite solution and 100 g of a 5% aqueous sodium hydrogencarbonate solution. After the organic solvent was distilled off, column purification (500 g of silica gel, toluene development) was made to obtain 11.0 g of a brominated phthalocyanine. It was elucidated by elemental analysis and FD-MS that 6.6 bromine atoms were substituted on side chains. ______________________________________Elemental analysis: C.sub.68 H.sub.72 N.sub.8 O.sub.4 Br.sub.6.6 Pd C H N Br______________________________________Found (%) 48.15 3.84 6.63 30.95Calcd. (%) 48.07 4.00 6.59 31.04______________________________________ λ.sub.max =691.5 nm ε.sub.g =1.2×10.sup.5 g.sup.-1 EXAMPLE 6 10 g of the brominated phthalocyanine synthesized in Example 5 were dissolved in 1000 g of n-octane, and the solution was then applied onto a substrate made of a polycarbonate by spin coating to form an optical recording medium having a recording layer of thickness of about 800 Å. When recording was done at a power of 7 mW by a semiconductor laser beam at 780 nm, a CN ratio of 60 dB was obtained. Reproduction was carried out 10 5 times by a reproduction beam at 0.5 mW, but any record did not change. Furthermore, even after 1000 hours under conditions of 80° C. and 80% RH, any record did not change. EXAMPLE 7 26.6 g (0.1 mol) of 3-(3,5-dimethyl-1,6-heptadiene-4-oxy)phthalonitrile synthesized in Example 5, 15.2 g (0.1 mol) of DBU and 120 g of n-amyl alcohol were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then heated up to 110° C. under a nitrogen atmosphere. Moreover, 3.0 g (0.03 mol) of cuprous chloride were added at the same temperature, and reaction was carried out at 135° C. for 10 hours. After completion of the reaction, the solution was cooled, and insolubles were then removed by filtration. The resulting filtrate was concentrated under reduced pressure to collect the solvent. Afterward, column purification (500 g of silica gel, toluene development) was made to obtain deep green crystals of a phthalocyanine copper compound having unsaturated hydrocarbonoxy groups. Its yield was 21.4 g (yield ratio=76%). Maximum absorption wavelength (λ max ), gram absorptivity coefficient (ε g ) and the results of elemental analysis were as follows: λ.sub.max =706.0 nm ε.sub.g =1.6×10.sup.5 g.sup.-1 (solvent: toluene) ______________________________________Elemental analysis: C.sub.68 H.sub.72 N.sub.8 O.sub.4 Cu C H N______________________________________Calcd. (%) 72.37 6.38 9.93Found (%) 72.41 6.52 9.81______________________________________ 10 g (8.86 mmols) of copper tetra-α-(3,5-dimethyl-1,6-heptadiene-4-oxy)phthalocyanine were added to a mixed solution of 40 g of tetrahydrofuran, 40 g of n-hexane and 100 g of water, and 5.5 g (34.41 mmols) of bromine were added and reaction was carried out at 40° C. for 2 hours. After cooling to 20° C., 40 g of toluene were added, followed by separation. Successively, the resulting organic layer was washed with 80 g of a 10% aqueous sodium hydrogensulfite solution and 80 g of a 5% aqueous sodium hydrogencarbonate solution. After the organic solvent was distilled off, column purification (500 g of silica gel, toluene development) was made to obtain 13.7 g of a brominated phthalocyanine. It was elucidated by elemental analysis and FD-MS that 7.4 bromine atoms were substituted on side chains. ______________________________________Elemental analysis: C.sub.68 H.sub.72 N.sub.8 O.sub.4 Br.sub.7.4 Cu C H N Br______________________________________Found (%) 47.29 4.36 6.60 34.45Calcd. (%) 47.48 4.22 6.52 34.38______________________________________ λ.sub.max =706.5 nm ε.sub.g =1.2×10.sup.5 g.sup.-1 EXAMPLE 8 10 g of the brominated phthalocyanine obtained in Example 7 were dissolved in 1000 g of n-octane, and the solution was then applied onto a polycarbonate substrate by spin coating to form a recording layer of thickness of about 800 Å. Next, gold was sputtered thereon to form a reflective layer, thereby forming a CD-R medium. The reflectance of this medium was 73% (775-790 nm), and EFM signals could be written on the medium at a linear velocity of 1.3 m/sec at a power of 6.0 mW by the use of a semiconductor laser at 780 nm. At this time, an error rate was less than 10. EXAMPLE 9 5 g (4.50 mmols) of palladium tetra-α-(2,5-dimethyl-5-hexene-3-oxy)phthalocyanine synthesized in Example 1 were dissolved in 30 g of 1,1,2-trichloroethane, and 10 g of water were then added. Next, 6.4 g (45.0 mmols) of sulfuryl chloride (95 wt %) were added dropwise at 50°-60° C., and reaction was carried out at 60°-70° C. for 1 hour. After cooling to 30° C., a 10% aqueous sodium hydroxide solution was added dropwise until a pH of an aqueous layer portion became about 7.0. The resulting organic layer was separated and then added dropwise to 180 g of methanol, and the precipitated crystals were collected by filtration to obtain 6.8 g of a chlorinated phthalocyanine. It was elucidated by elemental analysis that 12 chlorine atoms were substituted, and it was also elucidated by NMR that the double bonds of side chains are all chlorinated. ______________________________________Elemental analysis: C.sub.64 H.sub.68 N.sub.8 O.sub.4 Cl.sub.12 Pd C H N Cl______________________________________Found (%) 49.55 4.40 7.30 27.45Calcd. (%) 49.75 4.44 7.25 27.53______________________________________ λ.sub.max =702.0 nm ε.sub.g =1.3×10.sup.5 g.sup.-1 EXAMPLE 10 5 g of the chlorinated phthalocyanine obtained in Example 9 were dissolved in 500 ml of dimethylcyclohexane, and the solution was then applied onto a polycarbonate substrate by spin coating to form a recording layer of thickness of about 800 Å. Next, gold was sputtered thereon to form a reflective layer, thereby forming a CD-R medium. The reflectance of this medium was 74% (775-790 nm), and EFM signals could be written on the medium at a linear velocity of 1.3 m/sec at a power of 6 mW by the use of a semiconductor laser at 780 nm. At this time, an error rate was less than 10. Comparative Example 1 9.6 g (0.24 mol) of 60% sodium hydride and 150 ml of N,N-dimethylformamide were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then stirred under the feed of nitrogen. Afterward, 29.5 g (0.25 mol) of 2-fluoro-1-cyclohexanol were added dropwise thereto at 20°-30° C. over 1 hour, and the solution was then stirred at the same temperature for 3 hours to prepare a sodium alcoholate solution. Next, 34.6 g (0.2 mol) of 3-nitrophthalonitrile and 150 ml of N,N-dimethylformamide were placed in a container equipped with a stirrer, and the above-mentioned sodium alcoholate solution was added dropwise thereto at 0° C. or less over 5 hours. After completion of the addition, the temperature of the solution was raised up to a level of 20°-30° C., and the solution was then stirred for 2 hours to bring reaction to an end. The thus obtained reaction solution was poured into 3 l of water and then stirred for 30 minutes, and 500 ml of toluene were added. After stirring for 30 minutes, the solution was allowed to stand to separate a toluene layer. After toluene was distilled off under reduced pressure, recrystallization was carried out from 600 ml of n-hexane to obtain 44.0 g of 3-(2-fluoro-1-cyclohexane-1-oxy)phthalonitrile (yield=90.0%). ______________________________________Elemental analysis: C.sub.17 H.sub.17 N.sub.2 OF C H N F______________________________________Calcd. (%) 68.83 5.36 11.47 7.78Found (%) 68.88 5.31 11.39 7.72______________________________________ Next, 22.4 g (0.1 mol) of the thus obtained 3-(2-fluoro-1-cyclohexane-1-oxy)phthalonitrile, 15.2 g (0.1 mol) of DBU and 120 g of n-amyl alcohol were placed in a container equipped with a stirrer, a reflux condenser and a nitrogen-introducing tube, and the solution was then heated up to 110° C. under a nitrogen atmosphere. Moreover, 3.0 g (0.03 mol) of cuprous chloride were added at the same temperature, and reaction was carried out at 135° C. for 10 hours. After completion of the reaction, the solution was cooled, and insolubles were then removed by filtration. The resulting filtrate was concentrated under reduced pressure to collect the solvent. Afterward, column purification (500 g of silica gel, toluene development) was made to obtain deep green crystals of a phthalocyanine copper compound having fluorine-substituted hydrocarbonoxy groups. Its yield was 21.4 g (yield ratio=76%). Maximum absorption wavelength (λ max ), gram absorptivity coefficient (ε g ) and the results of elemental analysis were as follows: λ.sub.max =704.0 nm ε.sub.g =1.5×10.sup.5 g.sup.-1 ______________________________________Elemental analysis: C.sub.56 H.sub.52 N.sub.8 O.sub.4 F.sub.4 Cu C H N F______________________________________Calcd. (%) 64.64 5.03 10.77 7.30Found (%) 64.55 5.08 10.80 7.38______________________________________ Comparative Example 2 5 g of the fluorinated phthalocyanine obtained in Comparative Example 1 were dissolved in 500 ml of n-octane, and the solution was then applied onto a polycarbonate substrate by spin coating to form a reocrding layer of thickness of about 800 Å. Next, gold was sputtered thereon to form a reflective layer, thereby forming a CD-R medium. The reflectance of this medium was 72% (775-790 nm), and in writing EFM signals on the medium at a linear velocity of 1.3 m/sec by the use of a semiconductor laser at 780 nm, a power of 10 mW was required. At this time, an error rate was 120. Examples 11 to 20, and Comparative Examples 3 and 4 Phthalocyanine compounds shown in Table 1 were synthesized by the same procedure as in Example 1, and CD-R media were prepared by the same procedure as in Example 2. Next, laser powers (mW) necessary to write EFM signals at a linear velocity of 1.3 m/sec by the use of a semiconductor laser at 780 nm were measured, and at this time, error rates were also evaluated. With regard to the evaluation of the error rates, ◯ means that the error rate is less than 10, and X means that the error rate is more than 10. The results are shown in Table 1. TABLE 1__________________________________________________________________________ WritingPhthalocyanine Power Error Rate__________________________________________________________________________Example 11 ##STR6## 4.5 mW ∘Example 12 ##STR7## 6.0 mW ∘Example 13 ##STR8## 6.0 mW ∘Example 14 ##STR9## 6.0 mW ∘Example 15 ##STR10## 5.0 mW ∘Example 16 ##STR11## 5.0 mW ∘Example 17 ##STR12## 6.5 mW ∘Example 18 ##STR13## 5.5 mW ∘Example 19 ##STR14## 5.0 mW ∘Example 20 ##STR15## 5.5 mW ∘Comp. Example 3 ##STR16## 10.0 mW xComp. Example 4 ##STR17## 105 mW x__________________________________________________________________________	A phthalocyanine represented by the formula (1) ##STR1## wherein each of R 1 , R 2 , R 3 and R 4 is independently an alkyl group substituted by 0 to 5 halogen atoms and having 1 to 20 carbon atoms, an alkenyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms or an alkynyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms, and at least one of R 1 , R 2 , R 3 and R 4 is substituted by the halogen atom; X is a halogen atom; each of k, l, m and n is independently a value of from 0 to 3; each of o, p, q and r is independently a value of 0, 1 or 2, and all of them are not 0 simultaneously; each sum of k and o, l and p, m and q, and n and r is independently in the range of from 0 to 4; Met is two hydrogen atoms, a divalent metal atom, a trivalent mono-substituted metal atom, a tetravalent di-substituted metal atom or an oxy-metal atom; an optical recording medium formed by adding this phthalocyanine to a recording layer; and a near infra-red absorbing agent comprising the phthalocyanine. The above-mentioned phthalocyanine can be used to provide the optical recording medium having excellent characteristics of reflectance, sensitivity, recording properties, stability to reproduction light, shelf stability and the like.	2
This is a continuation of application Ser. No. 08/075,157 filed on Jun. 10, 1993, now abandoned which is a divisional of application Ser. No. 07/767,169 filed on Sep. 26, 1991, now U.S. Pat. No. 5,244,614. FIELD OF THE INVENTION This invention relates generally to synthetic polymer filaments. More particularly, this invention relates to multicomponent trilobal fibers and a process for making the same. BACKGROUND OF THE INVENTION As used herein, the term "fiber" includes fibers of extreme or indefinite length (filaments) and fibers of short length (staple). The term "yarn" refers to a continuous strand of fibers. "Modification ratio" means the ratio R 1 /R 2 where R 2 is the radius of the largest circle that is wholly within a transverse cross-section of a fiber, and R 1 is the radius of the circle that circumscribes the transverse cross-section. "Trilobal fiber" means a three-lobed fiber having a modification ratio of at least 1.4. "Polymer composition" means any specific thermoplastic polymer, copolymer or polymer blend including additives, if any. Fibers which have a trilobal cross-section are known to be superior in many properties to those having a round cross-section. It is also known that combining two or more different polymeric components, whether the differences result from differences in additives or in the base polymer itself, produces fibers with improved properties for many end uses. For example, composite polyester fibers which are self-crimpable are disclosed in U.S. Pat. No. 3,671,379 to Evans et al. Also, U.S. Pat. No. 3,418,200 to Tanner describes a tipped multilobal composite fiber which is readily splittable. U.S. Pat. No. 3,700,544 to Matsui discloses composite sheath/core fibers having improved flexural rigidity. One of the cross-sections disclosed by Matsui is a triangular sheath/core fiber. These patents are merely examples of the variety of effects which can be achieved with multicomponent fibers. Methods and apparatus for preparing multicomponent fibers are also known. Exemplary apparatus are shown in U.S. Pat. Nos. 3,188,689 to Breen, 3,601,846 to Hudnall, 3,618,166 to Ando et al., 3,672,802 to Matsui et al., 3,709,971 to Shimoda et al., 3,716,317 to Williams, Jr. et al., 4,370,114 to Okamoto et al., 4,406,850 to Hills, and 4,738,607 to Nakajima et al. As is demonstrated from the previous patents, a great deal of effort has been directed to developing multicomponent fibers, as well as methods and apparatus for producing them. Yet sheath/core trilobal fibers are not presently produced effectively and with sufficient uniformity and efficiency. Also, there has been a lack of the ability to adjust the sheath components in any versatile manner. Thus, there remains a need for a method for producing a sheath/core trilobal fiber where the ratio of sheath to core is relatively accurately controlled as is the composition of the sheath component itself. It is believed that the fibers produced by such a method will find great utility in various applications. SUMMARY OF THE INVENTION The present invention is a method of producing a multicomponent trilobal fiber by providing a trilobal capillary defining three legs, three apexes and an axial center, directing a first molten polymer composition to the axial center and presenting a second molten polymer composition to at least one of the apexes so that the fiber has a core defining an outer trilobal core surface and a sheath abutting at least about one-third of the outer core surface. It is an object of the present invention to provide an improved process for preparing trilobal sheath/core composite fibers. A further object of the present invention is to provide a trilobal sheath/core composite fiber. After reading the following description, related objects and advantages of the present invention will be apparent to those ordinarily skilled in the art to which the invention pertains. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of the process of the present invention showing four polymer melt streams independently metered to a trilobal capillary. FIG. 2 is a bottom plan view of a spinneret capillary useful in the invention shown in FIG. 1 and looking in the direction of arrows 2--2. FIG. 3 is a cross-sectional view of the schematic of FIG. 1 taken along line 3--3 and looking in the direction of the arrows. FIGS. 3A-3D each represent legends depicting polymer streams A-D, respectively; FIG. 4 is a greatly magnified cross-sectional view of a two component sheath/core trilobal composite fiber of the present invention demonstrating an even sheath. FIG. 5 is a greatly magnified cross-sectional view of a sheath/core trilobal composite fiber of the present invention demonstrating an uneven sheath. FIG. 6 is a greatly magnified cross-sectional view of a four-component sheath/core trilobal fiber of the present invention. FIG. 7 is a cross-sectional view of a trilobal fiber of the present invention having a uniform uncolored sheath surrounding a colored core. FIG. 8 is a cross-sectional view of a trilobal fiber of the present invention and having a non-uniform three-component sheath surrounding a colored core. FIG. 9 is a cross-sectional view of a trilobal fiber of the present invention and having a two-component sheath partially surrounding an uncolored core. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS To promote an understanding of the principles of the present invention, descriptions of specific embodiments of the invention follow and specific language describes the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and that alterations and further modifications, and further applications of the principles of the invention as discussed are contemplated as would normally occur to one ordinarily skilled in the art to which the invention pertains. Applicant has discovered that, surprisingly, sheath/core trilobal fibers can be melt spun by routing molten sheath polymer to at least one apex of a trilobal spinneret orifice. There are many particular means which can be used to accomplish the objective and one of ordinary skill in the an would readily understand that the present invention is not limited to any one particular manner of routing the sheath polymer to the apex of the trilobal spinneret. By way of illustration, FIG. 1 schematically represents the routing process of the present invention. Portion 10 of a spinneret plate shows one capillary 11 and trilobal orifice 12. Individual molten polymer streams A, B, C and D are shown. Each molten polymer stream may be separately metered to spinneret capillary 11. The general route of each molten polymer stream to capillary 11 is shown with lines. As depicted in FIG. 1, each molten polymer stream, A, B, C and D, has its own extruder 14a, 14b, 14c and 14d, respectively, and metering pumps 15a, 15b, 15c and 15d, respectively. When each polymer stream is equipped with its own extruder and metering pump, a large variety of trilobal cross-sections are possible. This will be apparent from the following discussion. FIG. 2. is a bottom plan view of a trilobal capillary useful in the present invention and taken looking in the direction of arrows 2--2 in FIG. 1. Shown is trilobal orifice 12. Trilobal orifice 12 has three legs, 13, 13' and 13". Between each leg there is an apex, a, a' and a", respectively, as shown in FIG. 2. While the dimensions of the capillary are not critical, suitable capillary dimensions are such that each leg is about 0.554 mm long and about 0.075 mm wide. The depth of the capillary is 0.250 mm. The angle a between longitudinal axes of each leg may be about 120°. Turning to FIG. 3, a schematic cross-sectional view taken along line 3--3 of FIG. 1 and looking in the direction of the arrows is shown. Shown in the view is capillary entrance bore 14 which may be on the order of 4.3 mm in diameter. Port circle 15 has a diameter of about 2 mm. All apexal ports 17 and central port 18 which feed individual molten polymer streams to capillary 11 may be on the order of 0.60 mm in diameter. It should be recognized that while specific dimensions of ports, capillaries, orifices, etc., are made, these dimensions are not intended to limit the present invention but merely to fairly illustrate it. Other suitable dimensions may be scaled as will be readily apparent to those skilled in the art to which the invention pertains. To practice the invention, polymer stream C (identified by the legend of FIG. 3C) is directed through central port 18 to the center of trilobal orifice 12, where, after extrusion, stream C forms a trilobal core. Polymer streams A, B and D (identified by the legends of FIGS. 3A, 3B and 3D, respectively) are presented to apex a', a" and a, respectively, through apexal port 17 where, after extrusion, the streams A, B and D form a sheath abutting the trilobal core. Depending on the amount of polymer metered to each apex, the sheath shape is easily varied in a predetermined manner. For example, if no polymer is routed to apex a, then the sheath of the fiber defined by apex a' and a" will surround only about two-thirds of the outer core surface formed by polymer stream C. When polymer is fairly evenly metered to each apex, the resulting sheath/core trilobal has a sheath which occupies an approximately even perimeter around the core as demonstrated in FIG. 4. Polymer metered to an apex is, surprisingly, distributed approximately evenly over the lengths of the adjoining legs. Polymer metered to other apexes in approximately equal amounts results in a uniform sheath perimeter 20 surrounding the outer surface of trilobal core 21. The sheath produced from each apex stream is found to meet consistently at the leg tips of the extrusion orifice. Another feature of the process is the ability to prepare sheath/core fibers having relatively thicker portions of sheath in a predetermined manner as demonstrated, but somewhat exaggerated, in FIG. 5. For example, if polymer D is metered in an amount to apex a, then A and B are metered to apexes a' and a" in a lesser amount, the resulting filament has uneven sheath 25. The portion 26 of the sheath 25 defined by lobes 27 and 27' is thicker than that sheath portion defined by either 27' and 27" or 27" and 27. Lobes 27, 27' and 27" represent polymer extruded through legs 13, 13' and 13", respectively. Also, as noted, it is not necessary that all three apexal ports are utilized. Depending on the desired result, one or two of the apexal ports may be used to present molten polymer to the apexes of the trilobal spinneret orifice so that the sheath only surrounds about one-third or two-thirds, respectively, of the outer core surface. As another feature of the process anywhere between two and four different polymer compositions can be metered to a, a', a" and to the core to prepare a sheath/core trilobal having a multicomponent sheath as shown in FIG. 6. The polymer compositions may be composed of different compatible or compatibilized polymer bases or may differ by the additives, such as pigments, that are added through each route. One advantage of this process is that additives can be present in a single fiber but in different portions of the sheath. One particularly preferred aspect is where each polymer is of the same type or family, for example all nylon or all nylon 6, and the difference is in pigmentation. Apart from the novel routing of polymers to a spinneret capillary which are a part of the present invention, the other processing parameters used may be those established for the polymer being extruded. For example, when the present invention is used to make trilobal nylon 6 fibers, known nylon 6 melt spinning conditions may be used. Another embodiment of the present invention concerns a multicomponent sheath/core trilobal fiber where the sheath occupies an approximately even perimeter around the fiber. This sheath may be anywhere from about 10 to about 90 percent sheath, preferably about 15 to about 50 percent sheath. The modification ratio of the trilobal is preferably greater than about 1.4 and more preferably between 2 and 4. Such fiber may be pigmented in at least one of the core or sheath components or both. Such a fiber is illustrated in FIG. 4. Such sheath/core trilobal fibers can be made by the process of the present invention. Melt spinning conditions may be used as are known for the type of polymer composition being extruded. The fiber-forming polymers that can be used in the process and fiber of the present invention are high molecular weight substances having a fiber-forming property such as polyamides and their copolymers, polyethylene terephthates and their copolymers and polyolefins. After extrusion, the filaments are processed according to known fiber processing techniques suitable for any end use. The methods of processing will depend upon the intended use and will be according to conventional processes known to those ordinarily skilled in the art. Examples are draw-winding and spin-draw-winding processes. EXAMPLES 1-4 Four independent extruders, each having an independently controlled gear pump, supply four molten nylon 6 streams at 265° C. to a spinning assembly. The four molten nylon 6 streams are individually metered to discrete portions of a trilobal spinneret capillary. Three of the streams are metered to the apexes of the capillary lobes and one polymer stream is metered to the core. All compositions are nylon 6 and are made, extruded and metered according to standard nylon 6 melt spinning conditions. The polymer streams vary in composition. These compositions and the metering volumes of each are presented in TABLE 1. The cross-sections achieved by the metering schemes are shown in the figures as indicated. All clear components are natural nylon 6. The red, blue, gray and gold compositions refer to pigmented nylon 6. All four metering schemes produce sheath/core trilobal fibers suitable for drawing, texturing and use in a product such as carpet yarn. TABLE 1__________________________________________________________________________ No./Type Flow Cross-Example Component (g/min) % Volume Section__________________________________________________________________________ Colored core/uniform 2 per capillary FIG. 7 clear sheath Port A Clear 0379 11 Port B Clear 0379 11 Port C Red 2310 67 Port D Clear 0379 11 Colored uniform sheath/ 2 per capillary FIG. 4 clear core Port A Red 0.448 13 Port B Red 0.448 13 Port C Clear 2.103 61 Port D Red 0.448 13 Non-uniform sheath 4 per capillary FIG. 8 Port A Gold 0.831 24.1 Port B Red 0.355 10.3 Port C Gray 1.669 48.4 Port D Blue 0.593 17.2 Non-uniform sheath 3 per capillary FIG. 9 Port A Gold 0.831 24.1 Port B Red 0.355 10.3 Port C aear 1.131 32.8 Port D Clear 1.131 32.8__________________________________________________________________________	A method of producing a multicomponent trilobal fiber includes providing a trilobal capillary defining three legs, three apexes and an axial center, directing a first molten polymer composition to the axial center and presenting a second molten polymer composition to at least one of the apexes. The fiber produced has a trilobal core defining an outer core surface and a sheath abutting at least about one-third of the outer core surface.	3
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED testing apparatus and a method thereof that can be applied to backlights or lighting devices, and more particularly, to an LED testing apparatus and a method thereof that can ensure the reliability of LED tests by automatically performing a test to determine whether an LED is acceptable or defective, using visible rays or ultraviolet rays. 2. Description of the Related Art In general, light emitting diodes (LEDs) refer to semiconductor devices that emit light of various colors by configuring light sources by altering the compound semiconductor material, such as GaAs, AlGaAs, GaN or InGaInP. High-brightness, high-quality LED products rather than general-purpose, low-brightness LED products can be manufactured in line with the rapid progress in semiconductor technology. Furthermore, thanks to the realization of blue and white LEDs having excellent properties, the application range of these LEDs has been expanded to next-generation light sources and displays. Among these various LEDS, white LEDs will now be described with reference to FIG. 1 . FIG. 1 is a cross-sectional view illustrating the configuration of a white LED according to the related art. In a white LED, shown in FIG. 1 , according to the related art, lead frames 20 , consisting of first and second lead frames 21 and 22 , are formed on the inner bottom of a bucket 10 that may be formed of a synthetic plastic resin. A blue LED 30 is mounted and connected to the first lead frame 21 , while a diode 40 is mounted and connected to the second lead frame 22 . The blue LED 30 and the diode 40 are electrically connected to each other through a bonding wire 50 . Here, in order to emit white light using a blue LED and a yellow phosphor, a blue LED chip package is filled with an encapsulant 60 , formed of silicone resin mixed with a yellow phosphor. That is, the inside of the bucket 10 is coated with the encapsulant 60 , which contains the yellow phosphor, so that blue light, emitted from the blue LED 30 , changes into white light by the yellow phosphor in the encapsulant 60 . Recently, in order to complement green and red light-emitting areas, a green or blue phosphor as well as the yellow phosphor may be added to the encapsulant 60 . In the process of manufacturing the white LED according to the related art, the amount of the encapsulant filling in the package is as important as a ratio of mixing the silicon resin and the yellow phosphor. The encapsulant is supplied using a dispensing device. When the encapsulant is supplied, the bucket may not be coated with the encapsulant since the encapsulant is not properly supplied, or may overflow due to the excessive supply of the encapsulant. The ingress of foreign substances or damage to the bucket may also occur in the process of supplying the encapsulant. Since these defects cause a deterioration of the white LED, a test to determine whether the white LED is acceptable or defective is necessary in the manufacturing process. However, the test to determine whether a white LED is acceptable or defective is being performed with the naked eye. As for the test with the unaided eye, objective test criteria is ambiguous among inspectors, and the reliability of test results is reduced due to the difference in detection ability between skilled and unskilled inspectors. SUMMARY OF THE INVENTION An aspect of the present invention provides an LED testing apparatus and a method thereof that can ensure the reliability of LED tests by automatically performing a test to determine whether an LED is acceptable or defective, using visible rays or ultraviolet rays. According to an aspect of the present invention, there is provided an LED testing apparatus including: a first lighting unit generating first light and irradiating the first light onto an LED having an encapsulant including a fluorescent material excited by the first light to emit light having a longer wavelength than the first light; a second lighting unit generating second light having a longer wavelength than the first light to irradiate the second light onto the LED; an image acquisition unit receiving the light emitted from the fluorescent material and the second light reflected off the LED to acquire images of the LED; and an LED state determination unit determining whether the LED is acceptable or defective using the images of the LED acquired by the image acquisition unit. The first light may be an ultraviolet ray, and the second light may be a visible ray. The LED testing apparatus may further include a beam splitter reflecting the first light emitted from the first lighting unit to supply the reflected light to the LED, and transmitting the light emitted from the LED. The LED testing apparatus may further include a color filter arranged in an optical path of the light emitted from the LED, transmitting the light emitted from the fluorescent material and blocking light having a different wavelength. The first lighting unit may be switched on when the second lighting unit is switched off, and the second lighting unit may be switched on when the first lighting unit is switched off. The first lighting unit may be switched on when the second lighting unit is switched off, and the second lighting unit may be switched on when the first lighting unit is switched off. The color filter may be located in a filtering region set beforehand when the first lighting unit is switched on, and be located in a region other than the filtering region set beforehand when the second lighting is switched on. The image acquisition unit may acquire a first LED image using the light emitted from the fluorescent material and a second LED image using the second light reflected off the LED, and the LED state determination unit may extract a first edge line from the first LED image and a second edge line from the second LED image. The LED state determination unit may perform mask matching by comparing the second edge line with a reference edge line of the LED to determine a size and an arrangement direction of the encapsulant are the same therebetween. The LED state determination unit may perform defect detection to determine whether the LED is defective or not by comparing the first edge line with the second edge line. The LED state determination unit may determine at least one LED defect among overflowing of the encapsulant, uncoating of the encapsulant, a foreign substance included in the encapsulant and damage. The fluorescent material may be a yellow phosphor. According to an aspect of the present invention, there is provided an LED testing method including: performing an image acquisition operation to acquire a first LED image of an LED, coated with an encapsulant having a fluorescent material excited by an ultraviolet ray to emit light having a longer wavelength than the ultraviolet ray, by irradiating an ultraviolet ray onto the LED and using light emitted from the fluorescent material, and a second LED image of the LED by irradiating visible light onto the LED and using the visible light reflected off the LED; and performing an LED state determination operation to determine whether the LED is defective or not using the first and second LED images. The LED state determination operation may include extracting first and second edge lines from the first and second LED images, respectively, and determining whether the LED is defective or not using the first and second edge lines. During the LED state determination operation, mask matching may be performed by comparing the second edge line with a reference edge line of the LED to determine whether a size and an arrangement direction of the encapsulant are the same therebetween. During the LED state determination operation, overflow detection may be performed by comparing the first edge line with the second edge line of the LED to determine whether the encapsulant of the LED overflows. During the LED state determination operation, uncoating detection may be performed by comparing the first edge line with the second edge line to determine whether the LED is coated with the encapsulant or not. During the LED state determination operation, foreign substance detection may be performed to determine whether a foreign substance is present in the encapsulant of the LED by comparing the first edge line with the second edge line. 18 . During the LED state determination operation, damage detection may be performed using the second edge line to determine whether the LED is damaged. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a cross-sectional view illustrating the configuration of a white LED according to the related art; FIG. 2 is a block diagram illustrating the configuration of an LED testing apparatus according to an exemplary embodiment of the present invention; FIG. 3 is a flowchart illustrating an LED testing method according to an exemplary embodiment of the present invention; FIG. 4 is a flowchart illustrating an edge line extraction operation according to an exemplary embodiment of the present invention; and FIGS. 5A through 5D are views illustrating examples according to defect types. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the same reference numerals will be used throughout to designate the components having substantially the same configuration and function. FIG. 2 is a block diagram illustrating the configuration of an LED testing apparatus according to an exemplary embodiment of the invention. Referring to FIG. 2 , an LED testing apparatus according to this embodiment has a first lighting unit 200 , a second lighting unit 300 , a color filter 500 , an image acquisition unit 600 , and an LED state determination unit 700 . The first lighting unit 200 generates first light and supplies the first light to an LED 50 coated with an encapsulant containing a fluorescent material having a predetermined color. The second lighting unit 300 generates second light and supplies the second light to the LED 50 . The color filter 500 transmits light, having a predetermined wavelength, from light emitted from the LED 50 . The image acquisition unit 600 receives the light, having passed through the color filter 500 , and acquires an image of the LED 50 . The LED state determination unit 700 determines whether the LED is acceptable or defective, using the image of the LED acquired by the image acquisition unit 600 . One of the first light and the second light may be ultraviolet rays, and the other may be visible rays. For example, the first lighting unit 200 may generate ultraviolet rays as first light, while the second lighting unit 300 may generate visible rays as second light. Here, the LED testing apparatus according to this embodiment may include a beam splitter 400 that reflects the first light from the first lighting unit 200 to supply the reflected first light to the LED 50 , and transmits light, reflected against the LED 50 . Here, reference numeral 410 denotes a support body that holds the beam splitter 400 . The image acquisition unit 600 may acquire a first LED image using the first light of the first lighting unit 200 and a second LED image using the second light of the second lighting unit 300 . The first lighting unit 200 may be switched on when the second lighting unit 300 is switched off. The second lighting unit 300 may be switched on when the first lighting unit 200 is switched on. These operations of the first lighting unit 200 and the second lighting unit 300 may be controlled by the LED state determination unit 700 or an additional control unit. The LED 50 according to this embodiment may be a white LED coated with an encapsulant having a yellow phosphor. Here, when a yellow filter is employed in the color filter 500 , yellow light, generated from the encapsulant of the LED 50 , can pass through the image acquisition unit 600 by the ultraviolet rays, which are the first light of the first lighting unit 200 . The color filter 500 is positioned in a filtering region, set beforehand, when the first lighting unit 200 is switched on. Here, if the ultraviolet rays from the first lighting unit 200 do not pass through the encapsulant of the LED 50 and are combined with the yellow phosphor of the encapsulant of the LED 50 , yellow light is generated. The yellow light from the encapsulant passes through the image acquisition unit 600 via the color filter 500 . On the other hand, the color filter 500 is positioned in a region other than the filtering region, set beforehand, when the second lighting unit 300 is turned on. Here, the visible rays from the second lighting unit 300 pass through the encapsulant of the LED 50 and reflect from the bottom, the blue LED chip and the encapsulant of the LED 50 . Light reflecting from the LED 50 is transmitted to the image acquisition unit 600 without passing through the color filter 500 . The LED state determination unit 700 may extract a first edge line from the first LED image and a second edge line from the second LED image. The following items may be tested using the first and second edge lines and a reference edge line. First, the LED state determination unit 700 may perform mask matching to determine by comparing the second edge line with the reference edge line set beforehand, whether a size and an arrangement direction of the encapsulant are the same therebetween. Further, the LED state determination unit 700 compares the first edge line and/or the second edge line with each other to perform detect inspection to determine whether the LED 50 is defective or not. For example, the LED state determination unit 700 can determine at least one of the following defects: overflowing of the encapsulant, uncoating of the encapsulant, foreign substances present in the encapsulant, and damage, on the basis of the defect of the LED 50 . FIG. 3 is a flowchart illustrating an LED testing method according to an exemplary embodiment of the invention. Referring to FIGS. 2 and 3 , according to an LED testing method according to this embodiment, a first LED image of the LED 50 coated with an encapsulant containing a fluorescent material having a predetermined color is acquired using ultraviolet rays, and a second LED image is acquired using visible rays in operations S 100 and S 200 , mask matching is performed to determine by using the second LED image and a reference image set beforehand, whether a size and an arrangement direction of the encapsulant are the same therebetween in operation S 300 , and defect inspection is performed using the first LED image and/or the second LED image to determine whether the LED 50 is defective or not in operation S 400 . According to the LED testing method according to this embodiment, after performing the mask matching and the defect inspection in operations S 300 and S 400 , test results according to inspection items, that is, good and bad states, may further be stored in operation S 500 . During the mask matching in operation S 300 , first and second edge lines can be extracted from the first and second LED images, respectively. This process of extracting edge lines will be described with reference to FIG. 4 . FIG. 4 is a flowchart an edge line extraction operation according to an exemplary embodiment of the invention. Since a plurality of LEDs 50 are included in an LED array panel 10 , shown in FIG. 2 , each of the first and second LED images includes a plurality LED images. Thus, referring to FIG. 4 , a region with respect to one LED image is set for each of the first and second LED images in operation S 310 , noise in the LED image is reduced in operation S 320 , first image processing, called tracing, is performed, and second image processing, called threshold, is then performed. Through this edge line extraction process, a first edge line and a second edge line can be obtained from the first LED image and the second LED image, respectively. Referring to FIGS. 2 through 4 , during the mask matching in operation S 300 , it is determined by the second edge line and a reference edge line of a reference image, whether a size and an arrangement direction of the encapsulant are the same therebetween. The defect inspection in operation S 400 is performed to determine whether the LED 50 is defective or not using the first edge line and/or the second edge line. Specifically, the defect inspection in operation S 400 may include an overflow detection process to determine whether the encapsulant of the LED 50 overflows by comparing the first edge line and the second edge line; an uncoating detection process to determine using the first LED image and the second LED image, whether the LED 50 is coated with the encapsulant or not; a foreign substance detection process to determine whether foreign substances are present in the encapsulant of the LED 50 by comparing the first edge line with the second edge line; and a damage detection process to determine whether the LED 50 is damaged using the second edge line. The LED 50 according to this embodiment may be a white LED coated with an encapsulant containing a yellow phosphor. Here, in the above-described image acquisition process, the first LED image may be acquired by filtering yellow light created from the encapsulant of the LED 50 using ultraviolet rays, that is, the first light of the first lighting unit 200 . FIGS. 5A through 5D are examples showing images according to defect types. FIG. 5A shows an image corresponding to overflowing of an encapsulant among LED defects according to this embodiment. FIG. 5B shows an image corresponding to uncoating of an encapsulant among LED defects according to this embodiment. FIG. 5C shows an image corresponding to ingress of foreign substances among LED defects according to this embodiment. FIG. 5D shows an image corresponding to damage among LED defects according to this embodiment. Further, in FIGS. 5A , 5 B, 5 C and 5 D, a second LED image, obtained using visible rays, is shown on the left, and a first LED image, obtained using ultraviolet rays, is shown on the right. Hereinafter, the operation and effect of the invention will be described with reference to the accompanying drawings. An LED testing apparatus according to an exemplary embodiment of the invention will now be described with reference to FIG. 2 . In this embodiment, the first lighting unit 200 generates and supplies ultraviolet rays as first light, and the second lighting unit 300 generates and supplies visible rays as second light. First, the ultraviolet rays from the first lighting unit 200 reflect off the beam splitter 400 and are supplied to the LEDs 50 of the LED array panel 10 . Here, when the LED 50 is a white LED having a yellow phosphor, a yellow light is emitted due to the yellow phosphor contained in the encapsulant of the LED 50 . The color filter 500 according to this embodiment is positioned in a filtering region set beforehand when the first lighting unit 200 is switched on. Here, the yellow light from the LED 50 is input to the image acquisition unit 600 through the beam splitter 400 and the color filter 500 . Here, the image acquisition unit 600 may be a camera, and the color filter 500 corresponding to a colored fluorescent material is employed. When the colored fluorescent material is a yellow phosphor, a yellow filter may be used. The image acquisition unit 600 converts light, input through the color filter 500 , into an electrical signal to acquire the first LED image. The second lighting unit 300 according to this embodiment generates visible light as second light and supplies the visible light to the LED 50 . The visible light of the second lighting unit 300 passes through the encapsulant of the LED 50 and reflects off the bottom, the blue LED chip, and the encapsulant of the LED 50 . The color filter 500 is positioned in a region other than the filtering region set beforehand when the second lighting unit 300 is switched on. Here, the visible ray, reflecting off the LED 50 , does not pass through the color filter 500 and is transmitted to the image acquisition unit 600 . The image acquisition unit 600 converts the visible ray, input without passing through the color filter 500 , into an electrical signal to acquire a second LED image. Then, the LED state determination unit 700 according to this embodiment determines whether an LED is in a good state or a bad state using LED images from the image acquisition unit 600 , which will now be described in detail. The LED state determination unit 700 extracts the first edge line from the first LED image and the second edge line from the second LED image. First, the LED state determination unit 700 performs mask matching to determine by comparing the second edge line with the reference edge line set beforehand, whether the size and the arrangement direction of the encapsulant are the same therebetween. For example, by comparing the second edge line with the reference edge line set beforehand, if the second edge line and the reference edge line coincide with each other, it is determined that the size and the arrangement direction of the encapsulant are the same therebetween, and otherwise, it is determined that the size and the arrangement direction of the encapsulant are not the same therebetween. The LED state determination unit 700 may perform defect inspection to determine whether the LED 50 is defective by comparing the first edge line and/or the second edge line. Here, the LED state determination unit 700 may determine at least one of the following defects, which may occur in the LED 50 : overflowing of the encapsulant, uncoating of the encapsulant, foreign substances present in the encapsulant, and damage. An LED testing method according to this embodiment will now be described with reference to FIGS. 2 through 5 . First, the image acquisition process in operations S 100 and S 200 in the LED testing method according to the embodiment, shown in FIG. 3 , the first LED image of the LED 50 coated with the encapsulant, containing the fluorescent material having a predetermined color, is acquired using the ultraviolet ray and the second LED image of the LED 50 is acquired using the visible ray. The LED 50 according to this embodiment may be a white LED coated with an encapsulant containing a yellow phosphor. During the image acquisition process, yellow light created from the encapsulant of the LED 50 is filtered using the ultraviolet ray, which is the first light of the first lighting unit 200 , thereby acquiring to acquire the first LED image. Here, since the operations performed until the first LED image and the second LED image are acquired is the same as those described with reference to FIG. 2 , a description thereof will be omitted. When the mask matching is performed in operation S 300 , it is determined using the second LED image and the reference image set beforehand, whether the size and arrangement direction of the encapsulant are the same therebetween. Here, during the mask matching in operation S 300 , first and second edge lines are extracted from the first and second LED images, respectively. This process of extracting edge lines will be described with reference to FIG. 4 . Referring to FIG. 4 , since a plurality of LEDs 50 are included in an LED array panel 10 , each of the first and second LED images includes a plurality LED images. Thus, a region with respect to one LED image is set for each of the first and second LED images in operation S 310 , noise in the LED image is reduced in operation S 320 , first image processing, called tracing, is performed, and second image processing, called threshold, is then performed. By performing the first and second image processing, the first edge line and the second edge line can be obtained from the first LED image and the second LED image, respectively. Referring to FIGS. 2 through 4 , during the mask matching in operation S 300 , the second edge line and the reference edge line of the predetermined reference image are compared with each other to determine whether the size and arrangement direction of the encapsulant are the same therebetween. When the defect inspection is performed in operation S 400 , it is determined using the first LED image and/or the second LED image whether the LED 50 is defective. Specifically, during the defect inspection in operation S 400 , it is determined whether the LED 50 is defective, using the first and second edge lines extracted from the first and second LED images, respectively, and the reference edge line. The above-described defect inspection according to defect type may include overflow detection, uncoating detection, foreign substance detection and damage detection. During the overflow detection, it is determined whether the encapsulant of the LED 50 overflows by comparing the first edge line with the second edge line. For example, as shown in FIG. 5A , when an overflow of an encapsulant occurs, double or multiple lines appear on the first edge line. As a result, the first edge line and the second edge line do not coincide with each other. During the uncoating detection, it is determined whether the LED 50 is coated with the encapsulant or not by using the first edge line and the second edge line. For example, as shown in FIG. 5B , the first edge line appears distinct, while the second edge line is not detected. During the foreign substance detection, it is determined whether foreign substances are present in the encapsulant of the LED 50 by comparing the first edge line with the second edge line. For example, as shown in FIG. 50 , while the first edge line and the second edge line do not coincide with each other, an edge line corresponding to a foreign substance is shown within a region inside the outline of the first edge line. During the damage detection, it is determined using the second edge line whether the LED 50 is defective. For example, as shown in FIG. 5D , the second edge line is partially damaged. After performing above-described processes, test results according to inspection items, that is, good and bad states, obtained in operations S 300 and S 400 , may be stored in operation S 500 . As described above, according to the LED testing apparatus and the LED testing method according to the embodiments of the invention, LED images are acquired using ultraviolet ray lighting and visible ray lighting, and defects in the LED can be automatically tested comprehensively using edge lines extracted from the acquired LED images, thereby ensuring high reliability of LED testing results. As set forth above, according to exemplary embodiments of the invention, a test can be automatically performed using visible and ultraviolet rays to determine whether an LED is defective or not, so that the reliability of LED tests can be ensured. While the present invention has been shown and described in connection with the exemplary embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.	There is provided an LED testing apparatus. An LED testing apparatus according to an aspect of the invention may include: a first lighting unit generating first light and irradiating the first light onto an LED having an encapsulant including a fluorescent material excited by the first light to emit light having a longer wavelength than the first light; a second lighting unit generating second light having a longer wavelength than the first light to irradiate the second light onto the LED; an image acquisition unit receiving the light emitted from the fluorescent material and the second light reflected off the LED to acquire images of the LED; and an LED state determination unit determining whether the LED is acceptable or defective using the images of the LED acquired by the image acquisition unit.	6
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit under 35 U.S.C. §119 from Korean Patent Application No. 2003-91467, filed on Dec. 15, 2003, the entire content of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device and method for pumping fluids, and more particularly, to a device and method for pumping fluids employing the movement of gas bubbles through channels in microscale. 2. Description of the Related Art A micro-fluidic system refers to a system combining fluid dynamics and Micro-Electro-Mechanical Systems (MEMS), which can control fluid flows in micro units. For example, systems are being developed to perform tasks such as extracting DNA from very small test samples, checking gene mutation, and so on. Pumping fluids such as bio-fluids and chemical solutions through microscale channels is closely related to future micro-fluidic systems such as lab-on-a-chip (LOC) or micro total analysis systems (μTAS). U.S. Pat. No. 6,071,081 discloses a heat-powered liquid pump applying a film-boiling phenomenon. The pump is constructed with a chamber having inlet and outlet valves and a heating system located on the bottom surface of the chamber. The liquid is heated in the chamber by the heating system to form bubbles. The bubbles repeatedly expand and contract due to heat energy pulses. The bubbles act as a pressure source to expel liquid out of the chamber during bubble expansion and to draw liquid into the chamber during bubble contraction. Such a method can separate and transport liquid. The delivery volume of the pump depends on the bubble size and numbers. The above method has a disadvantage of degrading reliability where the pump runs for an extended time since small actuating values employed for net fluid movements, and preventing reverse flows, are delicate parts that have to be very carefully manufactured. Delicate parts like those can be damaged during extended pump running times. The paper of J. H. Tsai and L. Lin on “ A thermal - Bubble - Actuated Micronozzle - Diffuser Pump ” published on J. Microelectromechanical Systems , Vol. 11, No. 6, pp. 665-667 in 2003 addresses a mechanism for periodically re-forming and collapsing thermal bubbles. The micro pump has a resistance heater, a pair of nozzle-diffusing flow controllers, and a pumping chamber. Net flows are produced from the nozzles to the diffuser. This micro pump has some disadvantages such as particles possibly blocking the nozzle diffusion paths and damage to the pumping chamber due to bubble-collapsing pulses. U.S. Pat. No. 6,283,718 discloses a method of pumping liquid through channels. The liquid is disposed within a liquid chamber or channel. Power is applied to a micro pump to form vapor bubbles in the chamber or channel. Through a formation and collapsing cycle of the vapor bubbles, a pumping action of the liquid is effectuated. The paper of Song and Zhao on “ Modeling and test of thermally - driven phase change non - mechanical pump ” published on J. Micormech. Microeng, Vol. 11, pp. 713-719 in 2001 discloses a non-mechanical micro-pump driven by phase change. The pump has a glass tube and a few thermal elements distributed uniformly. Through control of the thermal elements along the glass tube, a pumping action is created. That is, changing the location where power is applied to heat sources produces the movement of vapor bubbles, which results in the pumping of liquid. The above pump requires a high power consumption of more than 10 Watts, features slow thermal responses, and requires manual control of phase growth. One severe disadvantage of the aforementioned pumping principles and pumps is that heating the pumped fluids to its boiling point can not be applied to most pumped fluids and corresponding micro-fluidic devices. The paper of N. R. Tas, T. W. Berenschot, T. S. J. Lammerink, M. Elwenspoek, A. Van den Berg on “ Nanofluidic Bubble Pump Using Surface Tension Directed Gas Injection ” published on Anal. Chem. Vol. 74, pp. 2224-2227 in 2002 addresses a method of manipulating liquid with a hydrophilic fluid channel having a minutely machined surface. The method is based on surface tension-directed gas injection through minute-sized holes in the channel walls. The injected gas is discharged by asymmetrically cross-sectioned surfaces of the micro channels, by which an infinitesimal quantity of liquid is transported. The drawback to this micro pump goes to specific structures of a manual pressure-applying mechanism and micro channels. Other disadvantages of such a pumping principle include a complicated manufacturing process and conductive heat loss. The inaccurate control on bubble transportation through channels and heaters requires a certain countermeasure on temperature control and packaging. SUMMARY OF THE INVENTION The present invention has been developed in order to solve the above drawbacks and other problems associated with conventional arrangements. An aspect of the present invention is to provide micro-fluidic device and pumping method for bio-fluids or chemical liquids through micro channels while eliminating solid frictions and heat loss. The foregoing objects and advantages are substantially realized by providing a micro fluid pumping device comprising a substrate having a lower pattern of two fluid reservoirs and two channels along which fluid moves between the two fluid reservoirs; a cover having an upper pattern formed for the two fluid reservoirs and the two channels; and a mobile light source externally emitting light at a certain level in order to enable the fluid to move from one fluid reservoir to another fluid reservoir by use of gas bubbles. Where fluid fills the two fluid reservoirs and the two channels, gas bubbles are injected into the two channels respectively through a predetermined sized hole formed in the substrate and/or the cover. The fluid is capable of absorbing light energy. Here, the substrate and the cover are formed of a transparent substance having a high light penetrability, such as quartz. Further, light beams from a mobile light source are directed at a front end portion of the gas bubbles in a direction of movement, whereby the mobile light source moves along one of the two channels and emits the light beams. The foregoing objects and advantages are substantially realized by providing a micro fluid pumping device comprising a first plate; a second plate; a structure adhesion layer adhered between the first plate and the second plate and having a pattern formed for two fluid reservoirs and two channels for moving fluid between the two fluid reservoirs; and a mobile light source externally emitting light beams at a certain level in order to heat a portion of the fluid to enable the fluid to move from one fluid reservoir to another fluid reservoir by use of gas bubbles injected into the fluid filling the two channels and reservoirs, wherein the bubbles are injected through predetermined sized holes formed in the first plate and/or the second plate and the fluid absorbs light energy. The first and second plates are formed of a transparent substance having a high light penetrability, such as quartz plates. Light beams from the mobile light source are directed at a front end portion of the gas bubbles in a direction of movement, whereby the mobile light source moves along one of the two channels and emits the light beams. The foregoing and other objects and advantages are substantially realized by providing a pumping method for a micro fluid pumping device having plates of predetermined structure for forming two fluid reservoirs and two channels for fluid movement between the two fluid reservoirs, comprising steps of injecting gas bubbles into the fluid filling the two fluid reservoirs and the two channels, through holes formed in the plates, and heating the fluid by the fluid absorbing light energy; and controlling light beams of predetermined level externally directed at the fluid in order to enable the fluid to move from one fluid reservoir to another fluid reservoir by heating a portion of the fluid adjacent to the injected gas bubbles. Further, the light beam control includes steps of emitting the light beams to generate capillary force with respect to the injected gas bubbles; and directing the movement of the light beams emitted in the light-emitting step along one channel. Further, the light beam control step directs the light beams into the fluid at a front end portion of the gas bubbles in a direction of movement. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view for schematically showing a micro fluid pumping device according to an embodiment of the present invention; FIG. 2 is a cross-sectioned view for showing a method for the device of FIG. 1 for injecting gas bubbles by use of a syringe; FIGS. 3A to 3D are cross-sectioned views for explaining a fluid pumping process for the device of FIG. 1 using gas bubbles; FIG. 4 is a perspective view for schematically showing a micro fluid pumping device according to another embodiment of the present invention; and FIG. 5 is a plan view showing a pump filled with two gas bubbles and for moving fluid by using gas bubbles according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The micro fluid pumping device and method according to the present invention can pump bio-fluids of liquid chemicals based on active bubbles through micro channels without any mechanical transport parts or resistance heaters since the device and method can precisely carry out the controls on gas bubbles by use of emitted light beams on microscale. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. During the description of the present invention, like parts and areas are designated with like reference numerals even in different drawings. FIG. 1 is a perspective view for schematically showing a micro fluid pumping device according to one embodiment of the present invention. A micro fluid pumping device 10 has cover 5 and substrate 5 ′ on which upper and lower patterns are formed for two fluid reservoirs 2 and 2 ′ and two channels 3 and 3 ′ respectively, and a light source module 6 installed to emit light beams moving along any of the two channels at a certain height over the cover 5 . A very small hole (see FIG. 2 ) is formed in a portion of the micro fluid pumping device 10 corresponding to the channels 3 and 3 ′ of the cover 5 in order to enable gas bubbles to be injected through an injection unit such as a syringe (see FIG. 2 ). The cover 5 and the substrate 5 ′ of the micro fluid pumping device 10 are formed to adhere to each other to form two channels 3 and 3 ′ connecting the two fluid reservoirs 2 and 2 ′. In order to facilitate the adhesion of the cover 5 and the substrate 5 ′ of the micro fluid pumping device 10 , structures in thin-film shape can be utilized for the cover 5 and substrate 5 ′ on which the fluid reservoirs 2 and 2 ′ and the channels 3 and 3 ′ are patterned respectively. With respect to FIG. 2 , in order to enable pumping actions after fluid is filled in the space formed inside the above micro fluid pumping device 10 , firstly, gas bubbles 12 formed by ambient air or by a certain inert gas are injected by a syringe 13 through a small hole 14 formed in the cover 5 and at a position corresponding to the micro fluidic channels 3 and 3 ′. Further, The gas bubbles 12 are driven by capillary force created by thermal control by light beams (not shown) emitted from light source module 6 . The light beams are directed at a front end of gas bubbles 12 injected in any of the channels 3 or 3 ′ through the transparent wall of the cover 5 . The thermal control of the gas bubbles 12 by the light beams reduces the capillary pressure of the fluid and expels the fluid together with the movements of the gas bubbles as the gas bubbles move through the micro channel 3 . FIGS. 3A to 3D are cross-sectioned views for explaining gas bubble movements due to the capillary force controlled by the light beams in the micro fluid pumping device of FIG. 1 . In FIG. 3A , the micro channel 3 is filled with fluid, and has a gas bubble 12 injected therein. The light beams 22 are directed at the fluid at the front end portion 24 of the gas bubble 12 through a portion of the cover 5 over micro channel 3 . The light energy is absorbed by fluid at the front end portion 24 and heats the fluid in a local area 26 . The heating temperature for the fluid is controlled by the intensity of the light beams, and can be maintained at a level which induces a capillary force. However, the temperature can be maintained lower than a temperature at which the fluid boils. Such heating reduces the surface tension of the heated fluid at local area 26 , and generates a capillary pressure difference between the ends of the gas bubble 12 . As a result of this capillary pressure difference, the gas bubble 12 moves at a speed of U b toward the center of the heated fluid at local area 26 , as shown in FIGS. 3B to 3D . Such movements of the gas bubble 12 form a pressure gradient ahead of the moving front end portion 24 of the gas bubble 12 , and push the fluid out of the micro channel 3 . Further, as the light beam 22 moves along the micro channel 3 as shown in FIGS. 3B to 3D , the gas bubble 12 moves toward the center of the newly heated fluid local area 26 as described above. Therefore, as the light beam moves at a speed of U f along the micro channel 3 , the gas bubble 12 is induced to move at the speed of U b . As a result, this movement creates a pumping action of the fluid, that is, of pushing the fluid out of the micro channel 3 . The fact that capillary force in the microscale field is predominant over other forces in fluid activities is well-known. Controlling such capillary force can serve as a driving mechanism in a fluid-pumping system. A proposed method uses capillary pressure in the micro channel to drive gas bubbles which are propelled by the thermal activities of the light beams. The volume ratio of thermal source distribution Q in a fluid due to light absorption can be expressed by Bouger-Lambert's law: Q=εI 0 exp[−ε( z 0 −z )] [Equation] where ε denotes the light absorption rate of the fluid, I 0 is density of focused light beams, z 0 is concentration of a fluidic channel, and z is the position in vertical axis. The local light heating on an end portion of a bubble causes the reduction of surface tension of the pumped fluid and generates a difference in surface tension, Δδ=\|δ′ T \|ΔT, between the end portions of the gas bubble and a heat capillary pressure difference, ΔP=2 cos θΔ6/R. Here, δT denotes a temperature surface tension coefficient, θ a contact angle, R a radius of curvature, and ΔT a temperature difference between the end portions of the gas bubble. Light energy can be directly absorbed by fluid and converted to heat very quick. Usually a conversion consumption time is 10 −10 seconds. Therefore, light beams have a prominent advantage in that they are very effective for generating heat. The use of light beams has another advantage in that the structure of heater and protection layers on the substrate for the micro pumping system is not complicated. Thus, the present invention provides a simplified structure, and special materials are not required to manufacture a pump. FIG. 4 and FIG. 5 are perspective and cross-sectioned views respectively. They schematically show a micro fluid pumping device employing the proposed fluid-pumping method according to another embodiment of the present invention. A micro fluid pumping device 110 has two quartz plates 105 and 105 ′, a structure layer 104 disposed between the two quartz plates 105 , 105 ′ and patterned to have fluid reservoirs 102 and 102 ′ and two channels 103 and 103 ′, and a light source module 106 installed to emit light beams moving along any of the two channels 103 and 103 ′ at a certain height over the upper quartz plate 105 . The micro fluid pumping device 110 has very small holes (not shown) at positions of the quartz plates 105 and 105 ′ corresponding to the channels 3 and 3 ′ so that gas bubbles can be injected through the holes by an injection unit such as a syringe (not shown). The three layers are formed to adhere to each other, so the micro fluid pumping device 110 has two fluid reservoirs 2 and 2 ′ and two channels 3 and 3 ′ which connect the two fluid reservoirs 2 and 2 ′, and these spaces are filled with fluid. Both channels 103 and 103 ′ connecting the two fluid reservoirs 102 and 102 ′ are 10 mm length, 1.2 mm wide and 50 μm deep. The structure layer 104 is formed to have two fluid reservoirs 102 and 102 ′ with same depth as the two channels 103 and 103 ′. A UV lamp is used for the light source 106 . FIG. 5 is a plan view of structure layer 104 . Fluid fills the reservoirs and channels. Two gas bubbles 112 and 112 ′ are injected inside. The first gas bubble 112 serves as a piston for pushing the fluid, and the second gas bubble 112 ′ serves as a guide for the flow of fluid. The controlled light beam 126 is emitted at an intensity of 50 mW/mm 2 from the UV lamp, and also is directed at the fluid near a front portion of the piston bubble 112 through the upper quartz plate 105 . The piston bubble 112 moves from left to right at a maximum velocity of U b =0.3 mm/s together with the light beam due to a capillary force, and, at the same time, the guide bubble 112 ′ is pushed in opposite direction due to a pressure head formed by the moving piston bubble. The above micro fluid pumping device showed a transport rate of more than 1 μl per minute in actual experiments. According to this embodiment of the present invention, the quartz plates are used in the micro fluid pumping device. However, other transparent substances can be used in place of the quartz plates, and diverse light beam sources can be used for the light source 106 , ranging from UV lamps to laser beams or even to VCSEL arrays. The micro fluid pumping device and method according to the present invention can be applied to diverse micro-fluidic systems since the device and method can move bio-fluid or chemical solutions more precisely by moving gas bubbles by light in microscale. Further, using light and bubbles enables the micro fluid pumping device and method to perform fluid pumping actions even in low temperatures. The foregoing embodiments are just typical examples of the present invention and they should not be construed to limit the present invention in any way. The present invention can be readily applied to other types of devices and methods. Also, the description of the embodiments of present invention is intended to be illustrative only, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.	The present fluid pumping method for micro-fluidic devices uses gas bubbles to move fluid by light beams. The light beams are emitted to the fluid near the gas bubble through an optically transparent cover and correspondingly heat the fluid in the micro channels. The liquid temperature variation changes the surface tension of the gas bubble near the heated fluid side, therefore, a pressure gradient between the end portions of the gas bubble generates accordingly. By moving the light beams, the moved pressure difference will be achieved, which will drive the gas bubbles and pump the fluid. Such a fluid pumping can simplify the structure of a micro-fluidic device and eliminate heat loss because of using a controllable light beam.	5
This invention relates generally to modular furniture systems and more particularly to a modular furniture system having a base or frame upon which a number of components are removably mountable. BACKGROUND OF THE INVENTION Conventional furniture, whether provided to the consumer in completed or modular form, tends to be quite limited in its appearance and function do to limitations in its structure. For example, a conventional one-piece sofa purchased as an assembled unit has a fixed appearance that, while it can be modified through potentially costly reupholstering to change the color or pattern should the owner decide a change in appearance is warranted, is limited to the same general overall shape. Modular seating systems are known which allow expansion by adding additional seating units to the structure, but the added units produced by the manufacturer may be substantially equal in appearance to the other units of the structure. Furthermore, once an additional seating unit is incorporated into the modular system, each unit may still limited in that alteration of that unit's appearance will likely require significant cost or effort, for example to reupholster the unit to change its color or pattern. Furthermore, conventional furniture assembled furniture is bulky and thus awkward and costly to transport. Even conventional modular furniture shipped as packaged unassembled components may take up a significant volume of space overall, for example due to components having uncomplimentary shapes that do not bundle well into a compact configuration, even though the components are each individually smaller and easier to handle than the resulting piece of assembled furniture, and thus may still be costly to ship. Empty space within shipping containers increases fuel consumption, as the number of articles transportable within a single vessel at one time is decreased. It is therefore desirable to provide a modular furniture system that facilitates relatively easy changes in appearance and can be packed into a volume reduced from that of the resulting product to lower shipping costs. SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided a modular furniture system comprising: a frame adapted to define a plurality of engagement sites; and a plurality of components removably engagable to the frame at the plurality of engagement sites to define a piece of furniture, each component being engagable to the frame at different positions thereon to facilitate a change in shape of the piece of furniture by rearrangement of the plurality of components relative to one another. Unlike prior art modular furniture systems wherein each component of the system is designed to engage with another component in a predetermined position and orientation relative thereto to produce a piece of furniture of predetermined shape, the components of the components of the preferred embodiment of the present invention can be attached to the base in different positions relative to the base and to one another to allow easy alteration of the furniture's shape to change the appearance or functionality thereof. Preferably each component is engagable to the frame at different orientations relative thereto. Preferably the frame is adapted to define a two-dimensional array of engagement sites. Preferably the two dimensional array of engagement sites is rectangular and each component is adapted to engage the frame at multiple engagement sites, the multiple engagement sites equaling a row of the two dimensional array in number of engagement sites. Preferably at least some of the plurality of components are each generally L-shaped to define a base portion adapted to extend along the frame when connected thereto and a second portion projecting from the base portion to extend away from the frame when connected thereto. L-shaped components provide a high-degree of adjustability in the shape of the furniture, as changing the positions and orientations of the L-shaped portions relative to the base will change the locations on the base at which the second portions project upward. For example, an L-shaped component can be used to create seating surfaces atop the base with one leg and an armrest or seatback projecting upward from the seating surface with the other leg. Preferably at least some of the components comprise cushioned portions to collectively define a seat when connected to the frame adjacent one another. Preferably at least one of the components comprises a tabletop. Preferably the frame comprises a plurality of frame members selectively engagable together to support the plurality of components at the plurality of engagement sites. Preferably the plurality of frame members are adapted for engagement together in a grid formation in which the frame members extend upward to intersections between crossing frame members to define cross-shaped projections over which corresponding cross-shaped slots in the plurality of components can be slid to engage with the frame. According to a second aspect of the invention there is provided a modular furniture system comprising: a frame adapted to define a plurality of engagement sites; and a plurality of components removably engagable to the frame at the plurality of engagement sites in a seat-forming configuration to define a seat atop the frame, the plurality of components being shaped and sized to be groupable together into a storage configuration when not engaged to the frame, the plurality of components when in the storage configuration being enclosable in a rectangular volume of lesser size than required to enclose the plurality of components when in the seat-forming configuration. Preferably the plurality of components comprises L-shaped components each having a base portion and a second portion projecting therefrom, the base portions of the L-shaped components being equal in length and the second portions of the L-shaped components being equal in length. Preferably each L-shaped component comprises flat sides to facilitate stacking of layers of the L-shaped components. Preferably the plurality of components comprise flat faces to facilitate flush face-to-face arrangement of the components in the storage configuration. Preferably exterior faces of each component are flat and perpendicular to one another to facilitate flush face-to-face arrangement of the components in the storage configuration. Preferably the components are arrangable into stacked layers in the storage configuration, the stacked layers defining a stack having a cylindrical outer periphery. Preferably the stack is cubical. Equally sized L-shaped components having flat and perpendicular external faces can be laid on their sides with the end of one leg of each L-shaped component sitting flush against a side of the opposite leg of the other L-shaped component to create a rectangular layer with a rectangular hole in the center. These layers can be stacked atop one another, and may be stacked with other rectangular layers formed by rectangular components. According to a second aspect of the invention there is provided a modular furniture system comprising: a frame adapted to define a plurality of engagement sites; and a plurality of components removably engagable to the frame at the plurality of engagement sites in a seat-forming configuration to define a seat atop the frame, each component comprising a core body and a removable cover that shrouds the core with the plurality of components in the seat-forming configuration. Having a removable cover on each components allows alteration of the furniture's appearance by replacement of the cover with one of a different fabric, color, pattern, thickness or shape. This also allows easy replacement of one or more worn cover, without necessarily requiring reupholstering of the entire furniture article. A supplier could stock multiple styles of covers to allow owners to purchase varieties of covers or to trade-in or recycle one style of cover for another. Preferably the cover comprises an inner padding layer adjacent the core and an outer layer disposed on a side of the inner padding layer opposite the core, the inner padding layer and the outer layer being separable from one another. Preferably the inner padding layer is formed to define a hollow interior similar in shape to the core. Preferably the cover has a hollow interior and is open at an end thereof to fit over the core. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, which illustrate an exemplary embodiment of the present invention: FIG. 1 is an exploded perspective view of a modular furniture system. FIG. 2 is a perspective view of a frame section of the modular furniture system. FIG. 3 is a perspective view of a first frame member of the modular furniture system. FIG. 4 is a perspective view of a second frame member of the modular furniture system. FIG. 5 is a perspective view of support-surface components of the modular furniture system arranged in a stacked storage configuration for transport. FIG. 6 is a perspective view of cross section of an L-shaped support-surface component of the modular furniture system. FIG. 7A is a cross sectional view of the L-shaped support-surface component as taken along line A-A of FIG. 6 . FIG. 7B is cross sectional view of the L-shaped support-surface component of the modular furniture system as taken along line B-B of FIG. 6 . FIG. 8 is a bottom plan view of a tabletop support-surface component of the modular furniture system. FIGS. 9 to 14 are perspective views of the modular furniture system with the support-surface components arranged in various configurations to alter the overall shape of the piece of furniture defined by the system. DETAILED DESCRIPTION FIG. 1 shows a modular furniture system 10 according to the present invention. The system 10 features a grid-like base frame 12 atop which a plurality of support-surface components 14 can be engaged to the frame in a variety of different positions and orientations relative to one another so as give the owner of the system control over the overall shape of the piece of furniture to be formed by the system 10 . The base 12 defines a two-dimensional rectangular array of engagement sites, at each of which one of the plurality of surface components 14 engages the frame 12 . Each engagement site is defined by a projection 16 formed at the intersection of frame members defining the grid like base frame 12 . A linear array of slots extend into each of the plurality of surface components 14 from a bottom surface thereof to receive respective ones of the upward extending projections 16 within the rectangular array of engagement sites provided by the base 12 . The slots and projections are shaped to allow one of the plurality of support-surface components to be lowered over any one projection in any one of four possible orientations spaced ninety degrees about a longitudinal axis of the projection. In other words, a component can be engaged to a projection for mounting on the base frame to extend along either a row or a column of the array of engagement sites in which the projection is located and in either direction along this row or column. In the illustrated embodiment, the base frame 12 is made up of two identical sections 12 a , 12 b . As shown in FIG. 2 , each section is made up of three first frame members 18 and three second frame members 20 . The first frame members 18 are spaced apart, parallel and longitudinally aligned with one another. The second frame members 20 are spaced apart, parallel and longitudinally aligned with one another and are perpendicular to the first frame members 18 . Shown in FIGS. 3 and 4 respectively, the first and second frame members 18 , 20 are nearly identical. Each first frame member 18 is a plate having the form of three identical and integral sections 18 a connected end-to-end and each being generally A-shaped. Each A-shaped section 18 a comprises a pair of legs 18 b converging upward on opposites sides of any empty space or generally triangular notch 18 c above which the integral legs 18 b meet. A linear vertical slot 18 d projects upward from the notch 18 c toward, but not reaching, the peak 18 e of the A-shaped section where the legs 18 b join. Along a partial length of the legs 18 b extending upward from the bottom 18 f of the frame member 18 , feet 18 g project laterally outward from the legs 18 b . Each second frame member 20 is similar, having three identical and integral A-shaped sections 20 a , each with legs 20 b converging upward from feet 20 g projecting laterally outward therefrom at the bottom edge 20 f at a distance below the peak of the triangular notch 20 c . The second frame member 20 differs in that the slot 20 d does not extend upward from the peak of the notch 20 c , but rather extends downward from the peak 20 e of the A-shaped section toward, but not reaching, the notch 20 c . As shown in the figures, the corners of the plate structured base frame members 18 , 20 may be rounded to prevent sharp points. As shown in FIG. 2 , the first and second base frame members 18 , 20 intersect at the peaks 18 e , 20 e of their A-shaped sections 18 a , 20 a . With the elongate plate-shaped first and second members perpendicular to one another, the slots 18 d , 20 d of their A-shaped sections are axially aligned and the first member 18 is lowered onto the second member 20 along the slot 20 d thereof until the ends 18 h , 20 h of the two engaging slots 18 d , 20 d contact to prevent further relative sliding between the two base frame members. The lengths of the slots 18 d , 20 d are such that when the first and second frame members 18 , 20 are fully engaged by their cooperation, the peaks 18 e , 20 e of the frame members 18 , 20 are at generally the same height. As the first and second base frame members 18 , 20 are identical except for the slots 18 d , 20 d , the inter-member spacing of the set of first members 18 is the same as that of the set of second members 20 . The intersection of a first frame member 18 with a second frame member 20 at the engaging slotted A-shaped sections 18 a , 20 a thereof defines a respective one of the projections 16 in the two dimensional array. The upward angling of the legs 18 b , 20 b of the A-shaped sections from the feet 18 g , 20 g engaging the ground surface on which the base is assembled at the bottom edges 18 f , 20 f means that these legs project upward from the rest of the base frame 12 to form tapered projections narrowing in the upward direction. The perpendicular intersection of the base frame members 18 , 20 gives these tapered projections 16 a cross-shaped cross section. As shown in FIG. 2 , the base frame section 12 a resulting from the engagement of frame members 18 , 20 of equal length in the grid defining fashion described above is square in plan. However, for use in assembling an elongate piece of furniture as shown in FIG. 1 , the two identical base frame sections 12 a , 12 b are simply coupled together at meeting ends thereof. Additional frame sections may be similarly added to the uncoupled ends or sides of the two sections shown to expand the footprint of the furniture. Alternatively, one of the two sections may be removed to reduce the base to one section to produce a small piece of furniture. Each section rests atop a ground surface at the bottom edges 18 f , 20 f of the feet 18 g , 20 g so that the plate-like frame members project perpendicularly upward from the ground surface. The perpendicular grid forming engagement of the frame members 18 , 20 provides stability despite the relatively narrow bottom edges 18 f , 20 f on which the structure stands. Looking at FIG. 5 , in which the plurality of support-surface components are shown grouped together and stacked into a compact storage configuration, three slots 22 extend into each of the plurality of components from a bottom face thereof (bottom referring to the lowermost face when the component is engaged to the base 12 , not the lowermost face in the storage configuration of FIG. 5 ). Each slot 22 has a cross-shaped cross section to receive the cross-shaped cross section of the projections 16 of the base 12 formed by the intersection of the perpendicular base frame members 18 , 20 . The slots 22 are linearly spaced along the bottom face with two of the four branches of each cross-shaped slot lying on a central longitudinal axis of the bottom face. The use of the right-angle cross-shaped cross section for the projections 16 and slots 22 ensures that when one of the plurality of support-surface components 14 is lowered into engagement with the base 14 , it will extend parallel to either a row or a column of the two-dimensional rectangular array of projections 16 in which the projection sliding into the slot lies. This cross section also allows the component to extend in either direction along the row or column from the projection to which it is engaged. As all the projections 16 are identical, as are the slots 22 , the user thus has the ability to select from a number of various positions or orientations for a component relative to the base 12 . This particular cross section also blocks significant relative rotation of a slot and a projection engaged therein. In the illustrated embodiment, relative rotation of a component about a projection axis is prevented anyhow the engagement of each component with multiple projections. The peaks 18 e , 20 e of the frame members 18 , defining the projections 16 are rounded or flattened so that the components do not sit atop a sharp point. The bottom surfaces of the components rest on or just above the top edges of the feet 18 g , 20 g projecting from the legs 18 b , 20 b of the A-shaped sections of the frame members 18 , 20 when the components are slid onto the projections 16 . It should be appreciated that base frames of alternate collapsible structure may be used to provide an array of projections upon which components may be mounted in various positions and orientations and that straight-edged cross sections other than the cross-shape may similarly prevent relative rotation between a projection and the slot engaged thereabout. However, such shapes may not be able to allow selective alignment with a row or column or may not be able to restrict orientation of the component about the projection axis to alignment with a row or column. For example, similar triangular cross sections for the projections and slots would prevent rotation once engaged, but as the sides of a triangle are not perpendicular, a user would be limited to possible alignment with only a row or only a column of the rectangular array. Square cross sections would ensure alignment and allow orientation along a row or column. Octagonal cross sections would allow orientation along a row or column, but would not automatically ensure alignment therewith by mere sliding of the slot over the projection. Also, the cross-shaped cross section can be provided using the easy to manufacture, easy to assemble, easy to disassemble and tightly packing flat plate frame members 18 , 20 . As shown in FIG. 1 , the illustrated embodiment features four L-shaped components 24 , each comprising a cylindrical base portion 26 of rectangular cross section and a projecting cylindrical portion 28 also of rectangular cross section projecting perpendicularly from an end of the base portion 26 . When the slots 22 in the bottom face of the component are lowered into engagement with projections 16 of the base 12 , the base portion 26 of the L-shaped component 24 extends along a base frame member and the projecting portion 28 projects upward away therefrom. A top face 28 a of the projection portion 28 distal to the base portion 26 is thus elevated above a top face 26 a of the base portion opposite the bottom face 24 a of the component from which the slots 22 extend thereinto. The plurality of support-surface components 14 is completed by two cylindrical components of rectangular cross section, a short rectangular component 30 and a tall rectangular component 32 . The short rectangular component 30 has a height equal to that of the base portion 26 of each L-shaped component 24 so that a top face 30 a of the short rectangular component 30 is flush with the top face 26 a of the base portion when the components are engaged to the base 12 . The tall rectangular component 32 has a height equal to that of each L-shaped component 24 so that a top face 32 a of the tall rectangular component 32 is flush with the top face 28 a of the projecting portion 28 when the components are engaged to the base 12 . FIG. 9 shows the same view as FIG. 1 , but with the plurality of components 14 having been lowered into engagement with the base 12 with each component extending along a respective row of the rectangular two-dimensional projection array, or in other words, widthwise across the base along a respective one of the frame members. The piece of furniture defined with the tall rectangular component 32 and short rectangular component 30 at opposite lengthwise ends of the base with the L-shaped components 24 between them may be considered to be a one-armed sofa. The top face 32 a of the tall rectangular component 32 defines the one arm rest at one end and the projecting portions 28 of the L-shaped components 24 define a back of the sofa extending toward the opposite end from the arm rest. The top faces 26 a of the base portions 26 of the L-shaped components 24 and the top face 30 a of the short rectangular component define a seating surface upon which a person may sit, lie or otherwise rest. FIGS. 6 and 7 illustrate the structure of the L-shaped components of the illustrated embodiment. Each component includes three separable layers. An L-shaped core 34 of rotationally molded plastic defines the main body of the L-shaped component 24 . Molded or otherwise shaped foam provides a padding layer 36 immediately surrounding the core 34 on all sides thereof except for being left open over a bottom face 34 a thereof. The padding layer 36 is thicker along the top surfaces 26 a , 28 a of the base and projecting portions 26 of the L-shaped component 24 , 28 to increase a cushioning effect at these thicker areas 36 a , 36 b which are potentially used to define seating surfaces and armrests. Outside the padding layer 26 on a side thereof opposite the core 34 , is a covering layer 38 of fabric sewn to be form fitting over the core and padding layer 36 to shroud them, except for likewise being open at the bottom surface 34 a of the core 34 . As shown in FIGS. 5 to 7 , a panel or plate 40 may be secured to the bottom surface 34 a of the core 34 to define the bottom surface 24 a of the component, the slots 22 extending through the panel 40 into the core 34 . The panel 40 reinforces the opening of each slot to prevent wear and damage to the core 34 when lowering the component onto a projection 16 of the base 12 and is secured to the core using fasteners 42 , such as screws threaded into the core through the plate 40 . Each being open at the bottom face 34 a of the core 34 , the padding layer 36 and the covering layer 38 each have a slip-cover structure which allows easy installation and removal of one or both of the layers, which are not fastened together and thus are completely separable. The padding layer 36 is simply slipped over the core 34 with the covering layer 38 then being slipped over the core and padding combination. This allows easy replacement of the layers, either together or separately, when desired by the owner, for example in response to significant wear of one or both layers or to change the appearance of the components by replacing the covering layer with fabric of another color or pattern. As the cores and a base made of metal or other strong durable reliable material should last an extremely long time, the life of the modular furniture system may be extended simply by replacing the padding and covering in response to wear. The replacement of these layers also increases the owner's ability to change the appearance of the furniture defined by the system. The covers for the rectangular components are similar to those for the L-shaped components with a hollow interior and open end, except they have a more simplistic rectangular shape due to the lack of a projecting portion. This lack of a two tier structure with two distinct upper surfaces at different heights also means that only a single thicker portion of padding is provided, along the unitary upper surface of the rectangular component. It should be appreciated that the modular furniture system 10 of the present invention need not be limited to use as a sofa, or even limited to particular use as a seating system. Indeed the modular furniture system may be used to provide support surfaces for purposes other than seating, and therefore may define such things as a table, a stand, or an entertainment center and should not be limited to in-home use. Where the system is not intended for seating use, the thicker portions 36 a , 36 b of the padding layer, or even the entire padding layer, may not be necessary. Even when not used for seating, the use of an outer covering layer however does allow quick and easy changing of pattern or color. The components used to define support surfaces arrangeable atop the base may be of alternate shapes or structure, and alternate materials that may be suitable for use in the modular furniture system will be appreciated by those of skill in the art. FIG. 5 shows the plurality of support-surface components 14 grouped together in a compact face-to-face configuration including stacking of layers of the components atop one another. The top two layers 44 , 46 of the stack are each formed by a pair of the L-shaped components 24 laid on their sides. The top surface 28 a of the projecting portion 28 of each L-shaped component 24 in one layer mates flush against the top surface 26 a of the base portion 26 of the other L-shaped component at an end of this top surface 26 a opposite the distal to the projecting portion of the same component. This defines a rectangular layer having a rectangular opening or hole in the center thereof. The bottom layer 48 of the stack is a rectangular layer of the same outer dimensions formed by the short and long rectangular components 30 , 32 laid on their sides with a top or bottom face of one resting flush against the top or bottom face of the other. The resulting stack has a cylindrical periphery and a rectangular cross section. Using FIG. 1 as a reference, all the components have the same length, and the sum of the height of an L-shaped component and the height of a base portion of another L-shaped component is equal to this common length. All the components also have the same width, which is one third of the common length. Comparing this information to the stacked arrangement of the components in FIG. 5 , the outer shape of the stack defines a cube. The height of the stack (the sum of three component widths from FIG. 1 ), the depth of the stack (the length of any one component from FIG. 1 ) and the width of the stack (the sum of the height of one L-shaped component and the height of the base portion of one L-shaped component from FIG. 1 ) are all equal. The cube of FIG. 5 is of significantly less volume than a rectangular box needed to enclose the plurality of components 14 when in the sofa-defining configuration shown in FIG. 9 , due to the empty space shown in FIG. 9 above the seat-defining surfaces 26 a , 30 a but below the armrest and back defining surfaces 28 a , 32 a . Having the components groupable into this reduced volume configuration makes the system easer to handle and less costly to transport and reduces fuel consumption by helping reduce empty volume within shipping containers, thereby increasing the number of articles transportable at one time in a single transport vehicle. As shown in FIG. 9 , the flat plate-like frame members used to form the grid-like frame 12 each have a length not exceeding that of the support-surface components, and so a box or container only slightly larger in one dimension than the cube-like stack of the components in the transport configuration can also contain the frame members. FIG. 8 shows a tabletop component 60 of the modular furniture system formed of a square plate having an area generally equal to that of one of the base frame sections 12 a , 12 b . Two sets of three spaced apart parallel grooves 62 , 64 are formed in a bottom surface 66 of the plate with the two sets arranged perpendicular to one another to form a grid pattern having the same dimensions as the grid or array defined by the base 12 . In other words, each intersection 68 of two perpendicular grooves 62 , 64 aligns with a projection 16 of the base when the tabletop 60 is lowered onto a three-by-three portion of the array of projections 16 such that the periphery of the tabletop 60 is generally aligned with the periphery of this square portion of the array. The tabletop 60 can be engaged atop the base 12 in place of three adjacent L-shaped or rectangular components to form a table portion of the piece of furniture. The cross-shaped projections 16 extend upward into the cross-shaped recesses formed at the intersection of the grooves 62 , 64 in the bottom surface of the tabletop component 60 , like the slot and projection cooperation of the L-shaped or rectangular components 24 , 30 , 32 with the base 12 , to prevent movement and rotation in the plane in which it rests atop the base 12 . The perpendicular intersecting grooves 62 , 64 provide a cross-shaped slot at each intersection 68 , but it should be appreciated that the full length grooves 62 , 64 extending fully across the tabletop 60 may be replaced with cross shaped recesses at positions thereon corresponding to the groove intersections, thereby creating a three-by-three two dimensional rectangular array of cross-shaped slots or recesses centrally located in the bottom surface 66 of the plate rather than a full grid pattern spanning the entire tabletop surface. The tabletop component 60 may be opaque, transparent or translucent and may be made from a number of suitable materials known to those of skill in the art, including metals, plastics and glass. Similar to the removable replaceable covers of the L-shaped and rectangular support surface components, substitution of one tabletop component for another allows a user to easily change the appearance of the piece of furniture, not only be changing relative positioning of the various components on the base, but also by substituting tabletop components of different materials, colors, patterns or slot-forming arrangements (i.e. a full grid pattern versus unconnected cross-shaped recesses). The tabletop has generally the same dimensions as a face of the stacked cube in FIG. 5 , and so can be easily incorporated into the same package as the stacked cube of cushioned components and the unassembled frame members 18 , 20 with minimal increase in package volume. FIGS. 9 to 14 show support surface components, chosen from among the L-shaped, rectangular and tabletop components 24 , 30 , 32 and 60 , engaged atop the base in different positions and orientations relative to one another, thereby forming different furniture configurations. FIG. 9 shows the modular furniture system 10 used to define a sofa-like piece of furniture having one arm rest and a backless open end opposite the end with the arm rest. This configuration uses both base frame sections 12 a and 12 b and has each of the plurality of components 14 extending cross-wise to the frame to engage a respective row of projections. FIG. 10 shows the modular furniture system 10 used to define a two-seat piece of furniture in which a pair of L-shaped components 24 defines one back-equipped seat on a first side of the tall rectangular component 32 . A second seat is defined on an opposite side of the tall rectangular component 32 by two adjacent L-shaped components 24 adjacent the tall rectangular component and the short rectangular component 30 adjacent the two L-shaped components on a side thereof opposite the tall rectangular component 32 . Each component extends cross-wise to the frame to engage a respective row of projections and the L-shaped components are oriented in the same direction so that their projecting portions 26 define backs of the two seats along a common side of the frame 12 . The short rectangular component 30 extends the seating surface of the second seat passed the back-equipped portion define by the L-shaped components to the respective end of the furniture piece. FIG. 11 shows the modular furniture system 10 used to define another two-seat piece of furniture. Unlike the configuration described above, here some of the plurality of components 14 extend cross-wise to the frame along a respective row, while others extend lengthwise along columns of the frame. At one end, the tall rectangular component 32 defines an armrest of the first seat, the remainder of which is formed by two adjacent L-shaped components 24 filling the remainder of the first base frame section 12 a having their projecting portions 26 define a seat back along one side of the frame. The second seat has two adjacent L-shaped components 24 projecting laterally from the first seat at the back-defining end thereof. The short rectangular component 30 extends parallel to these laterally projecting L-shaped components from an end of the first seat opposite the back thereof defined by the projecting portions of the first seat's L-shaped components. A person may sit on the second seat facing the same direction as someone sitting in the first seat, or may face an opposite or lateral direction relative thereto, the projecting portions of the second seat L-shaped components defining either a seat back or arm rest depending on what direction the seated person chooses to face. The projecting portion of the L-shaped component in the middle of the second seat also defines a partial armrest of the first seat. FIG. 12 shows the modular furniture system 10 used to define a seat and table piece of furniture. At one end, a seat is defined on the first base frame section 12 a in the same manner as the first seat of the configuration shown in FIG. 11 and described above. On the second base frame section 12 b , the tabletop component 60 is engaged atop the projections thereof to define a table immediately adjacent the seat. FIG. 13 shows the modular furniture system 10 used to define another seat and table piece of furniture. Here a back-equipped armless seat is defined at one end by two adjacent L-shaped components 24 extending cross-wise to the frame along a row of projections. The tabletop component 60 overlies the adjacent three rows, i.e. the remaining row of the second base frame section 12 b and two of the three rows of the first base frame section 12 a . At the other end of the furniture piece along the remaining unused row of the first base frame section 12 a , the short rectangular component 30 is disposed to define a narrow, flat cushioned seat or other support surface. FIG. 14 shows use of only the first base frame section 12 a , with the other section uncoupled therefrom either for use elsewhere to define a second pieces of furniture or disassembled into its flat frame members 18 , 20 for compact storage. Three components are used to define a single seat atop the first base frame section 12 a . The three parallel components include two adjacent L-shaped components 24 oriented in the same direction and the short rectangular component 30 parallel and adjacent thereto. The two projecting portions 26 of the L-shaped components 24 define either an arm rest or seat back depending on where the user chooses to sit and what direction he/she chooses to face. FIGS. 9 to 14 show the adaptability provided by the modular furniture system to allow for changes in shape in response to a desired change in appearance or function. In the illustrated embodiment, each component is about 30 inches long and 10 inches wide. The L-shaped components and the tall rectangular components are about 20 inches high, with the short rectangular component being 10 inches high. The cube into which the L-shaped and rectangular components are stackable due to their flat, perpendicular outer surfaces that can be mated in flush face-to-face arrangements is thus about 30 inches by 30 inches by 30 inches. The frame members 18 , 20 are about 30 inches long with the projections formed thereby when assembled being about 10 inches apart center-to-center along each row or column in the array formed. As the L-shaped and rectangular components are 10 inches wide and mounted centered on the projections, adjacent components thus fill the space between the projections of the array. The padding layer and cover are about 4 inches thick at the thicker padding areas, and are about 0.5 inches thick elsewhere. The cores are thus about 9 inches wide, about 6 inches and 16 inches high at the base portions and projecting portions respectively of the L-shaped components, about 6 inches high in the short rectangular component and about 16 inches high in the tall rectangular component. The tabletop components is about 30 inches by 30 inches. The entire modular furniture system can thus be shipped in a rectangular container not much larger than 30 inches by 30 inches by 30 inches. It should be appreciated that the structure, dimensions and shapes of the components and base may be somewhat altered while still providing the adaptable or collapsible advantageous of the present invention. For example, the number of slots provided in each component does not necessarily need to equal the width of the array of projections, as smaller components of different shapes may be used to increase the number of potential configurations. Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.	A modular furniture system comprises a frame adapted to define a plurality of engagement sites and a plurality of components removably engagable to the frame at the plurality of engagement sites to define a piece of furniture. Each component is engagable to the frame at different positions thereon to facilitate a change in shape of the piece of furniture by rearrangement of the plurality of components relative to one another. The plurality of components are shaped and sized to be groupable together into a storage configuration when not engaged to the frame. In the storage configuration, the components are enclosable in a rectangular volume of lesser size than when engaged to the frame. Each component comprises a core body and a removable cover that shrouds the core with the plurality of components engaged to the base.	0
BACKGROUND [0001] The present invention relates to an electrostatic discharge (ESD) protection circuit, and, more particularly, to an electrostatic discharge (ESD) protection circuit protecting an input/output (I/O) circuit provided with different supply voltages against electrostatic discharge. [0002] Electrostatic discharge (ESD) commonly occurs in semiconductor devices. The ESD phenomenon may occur when excessive electrostatic charge is drained through an I/O pad or a power pad of an integrated circuit (IC), damaging the IC. To solve this problem, manufacturers may provide an ESD protection circuit in IC devices. The ESD protection circuit is initiated before the pulse of electrostatic discharge exerts excessive pressure on IC devices, directing the ESD current to a potential terminal (preferably ground) to bypass IC devices, thus reducing the potential for ESD-related damage. [0003] With the continuing demand for faster and smaller devices, however, there is a trend to scale down the dimensions of semiconductor integrated circuit (IC) devices. As a result, there arises a decrease in the gate length and gate oxide thickness of MOS devices, leaving IC devices more susceptible to damage from electrostatic discharge. That is, the safe operating voltage of these devices is reduced to a lower level. Consequently, an adequate and more effective ESD on-chip protection circuit must be designed to protect the IC against ESD-related damage. [0004] Furthermore, many ICs are required to receive input signals from peripheral devices having an operating voltage exceeding the core logic voltage of the IC devices. Such I/O signals can cause reliability problems if a suitable voltage protection circuit capable of withstanding higher input signal voltages is not incorporated. Accordingly, it is desirable to have an ESD circuit allowing suitable protection for a lower core voltage circuit when higher input/output voltage is present. [0005] Hence, there exists a need for a more effective ESD protection circuit for accommodating circuits with varying operating voltage range to overcome the problems of the related art. SUMMARY [0006] The present invention is generally directed to an electrostatic discharge (ESD) protection circuit protecting an input/output (I/O) circuit provided with different supply voltages against electrostatic discharge. According to one aspect of the invention, the ESD protection circuit comprises a stacked NMOS transistor configuration, a triggering circuit and a disabling circuit. The stacked NMOS transistor configuration is coupled between a first power rail and a second power rail for receiving an ESD current from the first power rail and directing it to the second power rail during an ESD event. The stacked NMOS transistor configuration comprises at least a first NMOS transistor cascaded to a second NMOS transistor and has a gate coupled to a third power rail. The triggering circuit is coupled between the first power rail and the substrate of the stacked NMOS transistor configuration via a node. When an ESD event occurs, a trigger current is supplied to the stacked NMOS transistor configuration. The disabling circuit is coupled between the node and the second power rail for disabling the triggering circuit during normal operation. The third power rail has a third voltage level which is lower than the first voltage level of the first voltage rail but greater than the second voltage level of the second voltage rail during normal operation. [0007] According to another aspect of the invention, an ESD protection circuit is disclosed. The ESD protection circuit comprises a stacked NMOS transistor configuration, a triggering circuit and a disabling circuit. The stacked NMOS transistor configuration is coupled between a first power rail and a second power rail for receiving an ESD current from the first power rail and directing it to the second power rail during an ESD event. The stacked NMOS transistor configuration comprises at least a first NMOS transistor and a second NMOS transistor. The first NMOS transistor has a drain connected to the first power rail, a gate connected to a third power rail via a first resistor, a source coupled to the drain of the second NMOS transistor and the gate of the second NMOS transistor is connected to the source of the second NMOS transistor and the second power rail. The triggering circuit is coupled between the first power rail and the substrate of the stacked NMOS transistor configuration and comprises diodes coupled in series including at least an anode coupled to the first power rail and a cathode coupled to the disabling circuit at a node wherein the diodes are conductive for supplying a trigger current to the stacked NMOS transistor configuration during an ESD event. The disabling circuit is coupled between the node and the second power rail for disabling the triggering circuit during normal operation. The third power rail has a third voltage level which is lower than the first voltage level of the first voltage rail but greater than the second voltage level of the second voltage rail during normal operation. [0008] In one embodiment of the present invention, an ESD protection circuit comprises a stacked NMOS transistor configuration, a triggering circuit and a disabling circuit. The stacked NMOS transistor configuration is coupled between a first power rail and a second power rail for receiving an ESD current from the first power rail and directing the ESD current to the second power rail during an ESD event. The stacked NMOS transistor configuration comprises at least a first NMOS transistor and a second NMOS transistor wherein the first NMOS transistor has a drain connected to the first power rail, a gate connected to a third power rail via a first resistor, a source coupled to the drain of the second NMOS transistor and the gate of the second NMOS transistor connected to the source of the second NMOS transistor and the second power rail. Moreover, the transistors in the stacked NMOS transistor configuration are thin-gate devices. The triggering circuit is coupled between the first power rail and the substrate of the stacked NMOS transistor configuration via a node. The triggering circuit comprises a PMOS transistor including a source coupled to the first power rail, a drain coupled to the node and a gate coupled to the first power rail via a second resistor wherein the NMOS transistor is a thick-gate device and is turned on to generate the trigger current to the stacked NMOS configuration during an ESD event. The disabling circuit is coupled between the node and the second power rail for disabling the triggering circuit during normal operation. The third power rail has a third voltage level which is lower than the first voltage level of the first voltage rail but greater than the second voltage level of the second voltage rail during normal operation. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: [0010] FIG. 1 is a schematic diagram of an ESD protection circuit according to an embodiment of the invention; and [0011] FIG. 2 is a schematic diagram of a charge pump according to another embodiment of the invention. DETAILED DESCRIPTION [0012] With reference to FIG. 1 , a circuit diagram illustrates an ESD protection circuit 100 according to a first embodiment of the invention. The ESD protection circuit 100 of the invention is arranged between power rails V I/O and V ss , and designed to protect a circuit 102 such as an I/O buffer, which is implemented by thin gate MOS transistors. Power rails V I/O and V ss are connected respectively to an I/O voltage level V I/O and V ss (preferably I/O ground). The ESD protection circuit 100 comprises a stacked NMOS configuration 106 , a triggering circuit 108 and a disabling circuit 110 . [0013] The stacked NMOS transistor configuration 106 is arranged between power rails V I/O and V ss and comprises at least a NMOS transistor N 1 cascaded to a NMOS transistor N 2 . More particularly, the transistor N 1 has a drain connected to power rail V I/O , a gate connected to a power rail V core with a core voltage level V core via a resistor R 1 and a source coupled to the drain of the transistor N 2 wherein the core voltage level V core is lower than I/O voltage level V I/O and I/O ground voltage V ss is lower than V core . The gate and source of transistor N 2 are coupled together to power rail V ss . During normal operation, the gate to source voltage or the gate to drain voltage of the stacked NMOS transistor configuration 106 is within the supply voltage of core circuit, V core . Thus, the stacked NMOS transistor configuration 106 can be implemented by thin gate NMOSs used in a core circuit while maintaining the reliability of the ESD protection circuit 100 . [0014] The disabling circuit 110 comprises a NMOS transistor N 3 and a capacitor 118 . The transistor N 3 has a gate coupled to power rail V core through a resistor R 1 , a source coupled to power rail V ss , and a drain coupled to the triggering circuit 108 and the substrate of the stacked NMOS transistor configuration 106 via a node M. [0015] In this embodiment, the triggering circuit 108 comprises a diode string including at least an anode coupled to power rail V I/O and a cathode coupled to the disabling circuit 110 at the node M where during normal operation, the number of diodes in the triggering circuit 108 is adjusted according to the desired leakage current at the work temperature and the desired threshold voltage for turning on the diode string during an ESD event. [0016] During normal operation, the transistor N 2 is turned off, hence, the ESD protection circuit 100 is high impedance and non-conductive during normal operation. Additionally, transistor N 3 is turned on to draw away a leakage current, if any, from the triggering circuit 108 , to avoid turning on the stacked NMOS configuration 106 during normal operation. Furthermore, the diodes in the triggering circuit 108 are turned off because the threshold voltage of diodes in the diode string is adjusted to be greater than voltage level V I/O . Therefore, no trigger current is generated to trigger the stacked NMOS configuration 106 . [0017] During an ESD event, for example, where there is a positive voltage impulse occurring in power rail V I/O and power rail V ss is grounded, the diodes in the triggering circuit 108 are turned on to conduct a trigger current while the ESD stress from power rail V I/O is higher than the threshold voltage of the diode string. The capacitor 118 in the disabling circuit 110 is unable to react in time during an ESD impulse. Therefore, the gate of transistor N 3 is grounded and transistor N 3 is turned off during an ESD event. Consequently, the trigger current generated in the triggering circuit 108 is directed to the substrate of the stacked NMOS configuration 106 at node M and turns on the stacked NMOS configuration 106 to direct the ESD current to power rail V ss . [0018] The stacked NMOS configuration 106 in the ESD protection circuit 100 further comprises a parasitic bipolar 126 and a parasitic resistor R sub wherein the parasitic bipolar 126 has a collector connected to the drain of transistor N 1 , an emitter connected to the source of the transistor N 2 and a base coupled to the node M, and R sub is coupled between the node M and power rail V ss . During normal operation, the bipolar 126 is turned off. When an ESD event occurs, the trigger current from the triggering circuit 108 flows to the base of bipolar 126 and resistor R sub . When the bias voltage in the base of bipolar 126 is greater than the threshold voltage of bipolar 126 , the bipolar is turned on, directing the ESD current to power rail V ss . With a higher resistance of resistor R sub , the bipolar 126 is turned on earlier. As a result, the ESD protection circuit 100 is able to draw the ESD current away from power rail V I/O earlier. The voltage on the power rail V I/O is thus clamped to a low voltage level so as to protect the circuit 102 from ESD damage. Moreover, according to designed, during normal operation, the stress level on the ESD protection circuit MOS transistor gates are all less than or equal to V core . It would thus be desirable to utilize thin gate devices with the same gate thickness in the ESD protection circuit 100 and to reduce IC process costs. [0019] FIG. 2 illustrates another embodiment of the invention. The ESD protection circuit 200 is similar to that shown in FIG. 1 except that the triggering circuit 108 is replaced by a thick gate NMOS transistor P 1 and transistor N 3 is also a thick gate device having a gate coupled to power rail V I/O via a resistor R 2 . In this embodiment, a thin gate device is fabricated to operate safely when its terminals are supplied with V core or V ss voltage. Additionally, a thick gate device is provided for safe operation when terminals thereof are supplied with V I/O or V ss voltage. Transistor P 1 has a source coupled to power rail V I/O , a gate coupled to power rail V I/O through resistor R 2 and a drain coupled to the disabling circuit 210 at node M. During normal operation, transistor P 1 is turned off. When turned on by an ESD stress from power rail V I/O , transistor P 1 generates a trigger current during an ESD event. Similarly, the trigger current is directed to the bipolar 226 and the resistor R sub . With a bias current generated in the bipolar 226 , the stacked NMOS configuration 206 is turned on to discharge ESD current. [0020] While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.	An electrostatic discharge (ESD) protection circuit for protecting an input/output (I/O) circuit provided with different supply voltages against electrostatic discharge. The ESD protection circuit comprises a stacked NMOS transistor configuration, a triggering circuit and a disabling circuit. The ESD protection circuit is effectively disabled by the disabling circuit during normal operation. During an ESD event, a trigger current is generated by the triggering circuit to turn on the stacked NMOS transistor configuration and thus the ESD current is directed away. The ESD protection circuit also allows different voltages to be supplied during normal operation without damaging the transistors in the ESD protection circuit.	7
The technical scope of the invention(s) is the fine metering of liquids, also at high, pressure (especially the HPLC analysis technique). In this field pumps are needed which deliver free from or with a minimum of flow pulsation and employ two (principally) different design concepts. These are represented on the one side--as most frequent representative--by a reciprocating or high pressure pump set up with two cylinders or pumping units respectively, working together in parallel. On the other hand by a serial arrangement of the pumping units. In fact, with the pumping units arranged in parallel, usually a low pulsation is achievable--i.e. a very uniform and constant mass flow. At the same time such an arrangement of the pumping units requires larger space. Both cylinders are arranged side by side, and pertinent liquid channels at the high and low pressure side connect the parallel pumping units with alternately working pistons. Examples of the parallel high pressure pump set-up are described in source DE 27 37 062 (Zumtobel) and U.S. Pat. No. 3,917,531 (Magnussen). Besides the parallel high pressure set-up there are also the--mentioned--serial-type high pressure pumps with both pumping units serially arranged in flow direction. Principally there to, both pumping units are configured side by side--as with the mentioned parallel arrangement--however, the channels are embodied in flow direction in such way, that the liquid which is delivered under pressure from the first displacement chamber, is discharged via the second chamber (acting as storage vessel). Such an arrangement is object of source DE 32 03 722 C2 (Gynkotek) with regard to a special configuration of the pistons being linearly driven in a to each other co-ordinated mode with the aim of a reduction of flow pulsation in conjunction with a serial-type pump set-up. Concerning the technical background of the need for a continuous mass flow, here is expressly referred to column 6 in the mentioned documentation (patent). Aim and purpose of said pump set-up is to increase the accuracy of substance determination behind the separation column by minimizing residual pulsation. With the given application no interference signal must occur due to the (low) specific compressibility of the liquid being pumped (eluent) by the high pressure pump set-up. This is also a task of the invention(s), i.e., to further increase the constancy of the mass flow. This, however, not by a complicated mutual tuning of the reciprocating motions of the pistons (compare latest cited source) but by means of a principal redesign of the pump set-up. This especially, through pumping efficiency by means of minimizing the detrimental dead volume in the liquid displacement system. This task is solved by a serial-type dual piston pump set-up in a (sub)miniaturized design for constant and continuous mass flow with two pumping units arranged serially--with reference to the flow direction--to each other, each of them having a liquid displacement piston and with two check valves at the feeding side and at the high pressure side, in which a series block/disk-shaped constructional elements with their control surfaces adjacently positioned to each other to form a stack/sandwich-type build-up, with two of the constructional elements having each a liquid displacement chamber, perpendicularly orientated to the axis of the stack/sandwich-type build-up, receiving the respective pistons, and being fitted with liquid ducts for feeding and discharge in a parallel direction of this axis (claim 1). The same task finds its--independent-solution in an assembly concept for the mentioned high pressure pump set-up in which in the stack/sandwich build-up space a variety of functional units are arranged; the functional units--which perform different functions, such as directing the feeding flow, forming a gradient at the low pressure side, deviating the displacement flow and measuring the working pressure on the discharge side, liquid displacement by the main piston, liquid displacement by the storage piston--are combined with each other, directly sealed to each other by virtue of congruent shape within the stack/sandwich-type build-up space; the functional units in the stack/sandwich build-up space are radially fixed and axially pre-loaded by means of a clamping device (claim 14). Also the displacement assembly for the mentioned serial-type high pressure pump set-up solves the task put ahead: A liquid displacement unit for a high pressure pump set-up, working according to the serial liquid displacement principle to which only one kind of displacement chamber is associated and one valve directly at the inlet channel to the displacement chamber--mainly perpendicular to the longitudinal axis to said chamber (claim 20). Besides the mentioned (one) task, from the implementation of the invention(s) results the surprising beneficial effect that the serial-type pump set-up requires only an extremely small constructional space. This beneficial effect inherently originates from the invention's perception, to divide the serial-type pump set-up into--several--functional sub-units. Consequently, these functional sub-units can be fitted together in a sandwich-type build-up (claim 4) within smallest constructional space. The functional sub-units are block/disc-shaped constructional elements. They may be manufactured from non-metallic materials. They are fitted together to the invention's stack-type build-up resulting already in the serial-type pump set-up (claim 14). The liquid displacement chambers are orientated perpendicularly to the axis of the stack of the block/disc-shaped constructional elements (claim 1); in which the pistons are alternatingly reciprocating. Supplementary to the stack-type build-up of the block/disc-shaped constructional elements, the liquid displacement chambers are connected with each other by feeding (inlet) and discharge (outlet) bores, which in turn are orientated parallel to the stack axis. At the liquid feeding and discharge sides, check valves are arranged (claim 1,3) which represent, with their peripheral components, elements for the mechanical alignment. The stack/sandwich build-up is beneficial for the arrangement of the check valves since the block/disc-shaped constructional elements are positioned adjacent to each other. Consequently, no additional liquid connecting lines are needed between the pumping units. Thereby it is possible to integrate the inlet and the outlet check valves directly in the block/disc-shaped constructional element which forms such a pumping or liquid displacement unit. Thereby always only one check valve has to be fitted to each block/disc-shaped constructional element (claim 2,3). This promotes an additional beneficial effect of the invention, i.e. the compact design and the minimization of detrimental dead volume in the liquid displacement system respectively. The connecting check valves in inlet and outlet configuration can have an identical design for both block/disc-shaped constructional elements. Specifically, the elimination of all intermediary liquid connections is an advantage for the serial-type pump with its pump units (displacement chambers) adjacently joined together in flow direction. Thus the connecting line length is reduced to nearly zero and, by virtue of direct integration between the pumping units, and the other block/disc-shaped constructional elements having special function, the check valves can be actuated with higher precision (claim 3) leading to reduced residual pulsation. Reducing of flow pulsation--especially at very low flow rates--is furthermore enhanced by means of check valve design (claim 3); in special configuration check valve ball guide and ball stopper profile can be machined directly into the displacement chamber. An especially favorable design configuration of the check valves arranged between the block/disc shaped constructional elements is designing the check valve in the form of cartridges (claim 7). Such cartridges comprise one or two check valves. The check valve cartridges are mounted in such way between two adjacently joined block/disc-shaped constructional elements that half of their length inserts into each element. Thus not only the check valve incorporating liquid connection is provided between the functional discs, but also mutual alignment of the constructional elements along their perpendicular axis. Check valve or dummy cartridges can be inserted between all block/disc-shaped constructional elements comprised in the stack; thus between the storage head and the pumping head, between the inlet rotary valve and the pumping head, or between the storage head and the pressure sensor/bleeder valve unit. Depending upon he intended function the check valve cartridge may comprise one or two check valves. Furthermore, it is possible to employ a dummy cartridge which simply features a bore as liquid duct. Thus, e.g. the outlet side of the storage head can be fitted with such a dummy cartridge in order to provide a liquid connection to the pressure sensor/bleeder valve module, which represents the forth element of a serial-type pump set-up (Inlet rotary valve, delivery head, storage head and outlet module). Furthermore, obviously the possibility for a faster assembly is given (claim 14) for each of the block/disc-shaped constructional elements, each one bearing a specific function. They must only be arranged in the respective stack for forming a serial-type pump set-up. Inherently, maintenance and replacement of damaged functional units is facilitated. The feeding and discharge bores, or inlet and outlet liquid ducts in the block/disc constructional elements, which are mentioned in claims 1 to 7 are aligned with each other. Their location in the center of the parts facilitates manufacturing (claim 8). As a result shortest possible connections are achieved between the block/disc displacement chambers, leading to minimum dead volume. A summarized description of the mentioned functional units is given as follows: (a) One functional unit can be the "main head"; it represents the main pumping unit (claim 1) (b) An additional functional unit can be the "storage head", representing the storage pumping unit which is positioned behind the main head. Also the outlet check valve of the main head can be integrated within this functional unit, laying basis for necessarily short liquid connection between main head and storage head. Thus detrimental dead volume is minimized in the displacement system which entails residual pulsation of the delivery flow and to loss of pumping efficiency due to the specific compressibility of the liquid medium being pumped (claim 1). (c) One functional unit can bear switching valve function at the feeding side; this functional unit precedes the main head and enables the selection of different pumping media (claim 5) and the introduction of solvent gradients, generated at the low pressure side (controlled proportionating of different liquids during a defined period of time. Compare claim 4). (d) One functional unit can embody pressure monitoring and additionally, bleeder valve function; this functional unit is arranged behind the storage head. This units represents in the basic implementation of the design concept the high pressure terminal of the complete serial-type pump set-up. It allows to monitor pressure in the system by deviating the delivery flow onto a built-in sensor. (claim 6). For the control of exerted hydraulic forces, and the same time, in order to achieve internal and external sealing in the complete displacement system, mechanical restraining and pre-loading of the various sub-elements is required; this can be effected by insertion of respective peripheral sealing elements and by pre-loading the functional units in the stack/sandwich build-up between the arms of a yoke-type body, or within a common receiving bore of a housing block. In case of choosing a cylindrical shape for the block/disc constructional elements and consequently, embodying a cylindrical sandwich-type serial-type high pressure pump, the different block/disc-shaped functional elements can feature a flat section at the mantle surface, at which a piston guide bushing is to be placed, --intermediary sealed when being mounted, with the displacement piston reciprocating in the guide elements in transverse direction to the stack axis; said guide can be composed of a metallic bushing (stainless steel or titanium) and two guide rings from ceramic material fitted apart into the bushing (claim 10). Between the guide rings a rinsing chamber is formed, which discontinuously or continuously renewed volume of rinsing liquid (water) prevents the formation of salt crystals when pumping buffer solutions which deploy an abrasive effect onto the piston seals. Also, externally to each of he guide rings a peripheral sealing element can be arranged, sealing the rinsing liquid reservoir. The ceramic guide rings can be shrink-fitted into the bushing with their guide bore aligned to each other. The reservoir chamber to be supplied with rinsing liquid via capillary tubing ports. The basically changed build-up of the serial-type high pressure pump, with the two pump units--main head and storage head--is furthermore manifested by the assembly procedure for such a pump set-up (claim 14). Quite obviously, the functional units are arranged to each other in a stacking space, axially freely movable (in the first instance), radially however, fixedly guided. Axial fixation or pre-loading is subsequently performed by means of a clamping device; thus providing a completely functioning serial pump system, based on the combined functional units. From this appears the possibility for simple (dis)assembly, as well as the potential for miniaturized construction. Essentially, the functional units can have a cylindrical form (claim 15); thus manufacturing of the components and joining them together is facilitated. In special configuration, the outlet check valve of the main head can be directly integrated into this unit or alternatively, partly into the storage head arranged behind (claim 16). The valves can be based on check valves (claim 17 to 19); with the sandwich build-up the valve balls can be inserted at the appropriate position. By the direct integration of the check valves special holding and mounting devices are made obsolete. Alone the valve ball is paired with a seat, which is inserted into the valve chamber after having placed the ball into the (integrated) ball stopper/ball guide bore (claim 17). Additionally, the seat can be backed by a--sealing--flange ring (claim 18). Said sealing ring facilitates the (radial) alignment of the stack. Special emphasis has to be made of the multi-bore ball guide bore (claim 17), allowing a direct machining into the block disc, eliminating the need for separate ball guide and ball stopper elements. As a result, the check valve comprises less peripheral components. A closely related invention suggests for both the main head and the storage head the use of a liquid displacement chamber of identical design (claim 20). This aims for allowing a rational manufacturing of the serial-type high pressure pump set-up (claim 1). Said functional block features a liquid displacement bore with the piston seal, and in perpendicular direction, the inlet bore and outlet bore, with check valve at the inlet side each. The described functional block can be modified for the embodiment of additional functions. In order to achieve a constant delivery special attention has to be also paid to the piston drive. In order not to efface the surprising beneficial effect that the serial-type high pressure pump needs any longer only for a minimum of constructional space, the drive system must ensure constant delivery and minimum dimensions as well. Otherwise the liquid displacement assembly of the serial pump which can be specially small built would be burdened by an oversized drive unit. Therefore, a Z-shaped drive piston is suggested, which essential features are summarized in claim 21. Thereby the Z-drive piston features a first arm and a second arm which both are mainly orientated in parallel to each other. The first arm is indirectly in contact with a rotating cam. This force transfer allows the Z-drive piston--being guided by means of two guide rods mounted apart from each other--a reciprocating motion. Since two guide bearings are foreseen, which are sliding on the guide rods mounted apart, a highly precise parallel displacement of the Z-lever (drive piston) is achieved. Additional anti-canting and anti-rotation devices are made obsolete. The Z-drive piston generates besides compactness an enhancement in the flow constancy by avoiding system elasticity. It finally also simplifies the assembly and the adjustment of the drive. Both mentioned arms can be connected by means of an intermediary arm (claim 22). This does not change the rigidly mechanical connecting of arms, because the intermediary arm connects both arms mechanically rigid; this, being mainly in perpendicular alignment with the first mentioned arms. The cam by which means the drive force is exerted onto the Z-drive piston can (indirectly) be effective onto the first arm via a rotating roller; a compression or a tension spring is employed to generate the filling stroke by inducing a counter load at the first arm, ensuring that the mechanical contact between the roller and the cam is never lost (claim 23). When using a tension spring, this spring is acting on the side of the first arm onto which the roller is not being effective (claim 24). Arranging both the stationary guide rods on both sides of the point of force introduction for the lower arm, a symmetrical configuration is yielded, which allows a specially precise reciprocating motion. Canting and rotating motions are eliminated if the guiding rods travels through the intermediary arm and when this arm is fitted with two bearing elements which allows sliding on the guide rod (claim 28). Both the displacement pistons in the main head and the storage head for the serial-type pump set-up are reciprocatingly actuated by drive pistons of the described design. The displacement pistons are sideload-free--with reference to the piston seals --actuated within a bushing made from stainless steel or titanium, which features two ceramic rings, fitted apart therein, as actual guiding elements (claim 11). A special restraining device is needed in order to press the precisely aligned piston guide bushings against the block/disc-shaped constructional elements which are configured as main head and storage head by a force which excludes resilience under the hydraulic load being effective onto the piston seal during pump operation. Such a restraining device can be e.g. a screw connection by which means the piston guide bushing is pressed against the flat section at the outlet of the displacement chamber bore of the pertinent [respective] block/disc-shaped constructional elements. For this purpose a guiding is needed which aligns the guide bushing sideload-flee in reference to the piston seal. As a solution which is also simple from the manufacturing standpoint of view, a restraining device is here suggested, which features an elongated trunk which is simply to be guided at the housing body of the serial-type pump and a--transversely to the trunk axis--protruding fork section as tension hook. (claim 30). At the end of the elongated trunk a loading device is foreseen, which can be a screw which engages in a threaded bore within the trunk and is counter-held in the housing body of the serial-type pump set-up. (claim 33). This loading device makes the L-shaped holding hook which is formed by the fork arms and the trunk, slidable in parallel to the displacement piston (claim 32). A very precise parallel displacement of the L-shaped holding hook is achieved by means of two supporting buttresses at the trunk being offset to each other (claim 30); thereby it can be foreseen that the buttresses are offset in reference to both the longitudinal and the transversal axis of the trunk (claim 34). By configuring one of the buttresses as fork section which protrudes from the trunk body, a groove is formed (claim 31) through which the displacement piston travels freely. In this way a maximum of accessibility is achieved. Even after assembly of the block discs and the piston guide bushings, the displacement pistons can be shifted into the fork section of L-shaped holding hooks, and the piston guide bushings can be frontally pressed against their block discs by means of the restraining device, or the restraining force can be adjusted respectively. Applying the same procedure, in inverse sequence, the piston guide bushings can be removed from their block/disc-shaped displacement chambers in the sandwich stack; thereby, after having sufficiently loosened the L-shaped holding hook, the piston is completely released by withdrawing it from the fork-buttress together with the guide bushing, thus removing it from the block/disc-shaped constructional element. From the good accessibility results a construction which is especially easy to maintain. The same time the holding hook is easy to adjust, since it can be tightened or loosened via the loading device being always accessible (claim 35). One of the mentioned supporting buttresses can be configured as cross-pin which is located in the transition area of the trunk and the fork section and protrudes from both sides of the elongated trunk body (claim 36). With the at both sides protruding cross-pin--which could be also divided--the holding hook rests then upon the lateral shoulders of a guiding slot in the mounting flange of the housing body in which the trunk body of the holding hook is fitted with sufficient play. The L-shaped holding hook is especially compatible with the Z-drive (claim 30, claim 21) whereby the L-shaped hook is positioned between the Z-drive piston and the functional block discs of the serial-type pump set-up (claim 1). In their combination, both the Z-drive piston and the L-shaped holding hook promote a miniaturized build-up. Additionally, the restraining force by which the piston guide bushing is pressed against the functional block disc is strong enough to securely avoid any elastic deformation under the influence of the considerable hydraulic forces exerted onto the piston seal during the displacement stroke (Avoidance of system elasticity to maintain maximum pumping efficiency). In order to optimally introduce the loading force exerted by the L-shaped holding hook onto the piston guide bushing, a washer-type ring is foreseen, which also serves as backing ring for the secondary piston seal, providing dynamic sealing of the rinsing liquid reservoir in the guide bushing. The sandwich-construction concept described above in detail for a serial-type pump set-up can be extended by supplementary functional sub-units, and thus lay basis for various compact analysis systems which are based on precision liquid metering for substance separation, or for a chemical reaction for substance determination (claim 37). Based on the concept of arranging the functional sub-units of the displacement assembly for a serial-type pump set-up it is suggested, i.e. to incorporate a sample injection, separation column and detector cell block disc, in order to establish the complete wet part of a comfortably portable miniaturized HPLC analysis system. It is foreseen that the supplementary functional constructional sub-units are fitted with each other also without connecting tubings for the control of the liquid flow (eluent) (in order to avoid a detrimental effect on the achieved substance separation at certain locations, i.e. the transition from the separation column to the detector cell) (claim 38). In order to obtain congruent constructional form also for the (HPLC) separation column, which has usually the form of a straight tube, it is suggested to configure it as a bundle of columns with several packings in one basic body, with terminal late elements on each end, providing cross-and pass-through connections via small zig-zag shaped liquid channels, or alternatively, as plane separation sub-unit, containing a column packing in spiral or meander-shape form. Between the serial pumping set-up and the supplementary separation column sandwich sub-unit, a sample injection sandwich sub-unit is integrated, in order to allow the introduction of the sample. Directly to the outlet of the separation column sub-unit, a detector cell (separated from the detector) is attached for the substance determination. Eventually the connection between measuring cell and detector electronics is to be established by use of fibre optics. With regard to the sandwich design of the serial-type pump set-up reference is made to claims 1 to 13 (claim 40). This set-up generates the eluent flow which is discharged via the bleeder valve/pressure sensor functional unit, which is determined with regard to its chemical composition through the supply via the inlet functional unit (connection to different reservoirs via multi-port slider valve, claim 39). In a special case the inlet module can be a low pressure side gradient former which controls the mixing ratio of parallely fed-in liquids by the use of a timed program. The pumping set-up according to claim 12 allows with a higher than ambient pressure the metering of precisely defined liquid volumes. At the same time the precise metering is reproducible. Embodiments of the invention are described in greater detail. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 showing a serial-type pump set-up in sandwich design in which the functional sub-units 4,5,6,7 are arranged to each other in a stacking space, or are compiled to a stack 3, which is held together between two arms 2a, 2b of a U-shaped profile 2 in axial direction. FIG. 2 showing a magnified cross-section of the serial-type pump set-up which is here configured by four functional units, with two of them, representing the liquid displacement sub-units. FIG. 3 showing the cross-section through a Z-shaped drive piston for the serial-type pump set-up according to FIG. 1 and 2 which is especially compact and effectuates a kinematically highly precise reciprocating motion of the displacement piston. FIG. 4 and 4a showing holding hook 70, 71 providing the compression of the piston guide bushing 15, 16 with block disc elements 4,5 being arranged in stack construction ("sandwich"); whereby FIG. 4 shows the backside of the displacement piston 16,17 in top view (top view of displacement axis 28, 29) and FIG. 4 the cross-section through a z-drive piston 51, the holding hook 70, 71 and the liquid displacement chamber 4,5. FIG. 5 showing the same cross-sectional view as FIG. 1 and 2, however, with modified check valve configuration. FIG. 5a and 5b showing check valve cartridge (80, 81) featuring one or two check valves. FIG. 5c shows in cross section a dummy valve cartridge with a central through-boring. These cartridges and also the additionally shown dummy cartridge are arranged between the functional discs 6,5 and 4 or 4 and 7 respectively according to FIG. 5. All cartridges provide alignment for the functional discs and, in the case of the check valves cartridges, flow control. FIG. 6 shows a stack of functional units in which an inlet module 6, the serially operating displacement chambers 4, 5, an outlet module with pressure sensor and air venting valve 7, a sample charging valve 100, a separation column 200 with meander-like packing and a detector measuring cell 300 are combined to form an entire stack and in this way form the complete wet part of a miniaturized HPLC analysis system. FIG. 7 illustrates with an exploded view several of the above-described structural components which form the serial pump unit. The letter A here represents one of the valve cartridges 80 with its details enlarged. One of the conveyor pistons 17 is installed; the other conveyor piston 18 is shown in detail with the L-shaped clamping hooks 70, 71 in the unassembled state. DESCRIPTION OF THE PREFERRED EMBODIMENTS The function carriers 4 and 5 are illustrated in FIGS. 1 and 2 in cut-away view and in FIG. 7 in an exploded view. The displacement chamber boring in the function carriers 4, 5 expands according to FIG. 7 at the other end to form a groove to receive the piston seal 34 (e.g. jacket of PTFE with stainless steel springs to hold the sealing lip under tension) whose spine also assures the static sealing of the rinsing fluid present in the piston guide sleeve 16. For dynamic (unpressurized) sealing at the lower end of the guide sleeve 16 a secondary piston seal 33 is used which is supported by the shim ring 7. The end face of this ring which remains free forms the support for the clamping hook 71. In order for tensile forces generated by means of the fork shield 71c on this hook by tightening the clamping screw to be initiated free of side loads exactly parallel to the axis of the (ceramic) plunger 18, the contact surface of the shim ring 7 is kept convexly bulged. In order to assure an accurate alignment of the plunger 18 in the displacement boring relative to the corresponding piston seal 34, the paired surfaces of the displacement chamber 4, 5 and piston guide sleeve 16, 15 are precisely specified with respect to their maximum permissible deviation from flatness relative to the axis of the piston boring. This is also applicable with respect to the concentricity of the two ceramic rings 31, 32 fixed in the piston guide sleeve 16, 15 as the actual guiding elements. These guiding rings are spaced apart in order to achieve the desired two-point support. By spacing the rings, in the piston guide sleeve 16, 15 a chamber is formed which permits through connections a back flushing of the piston seal 34 in the displacement chamber 4, 5 (prevention of the formation of salt crystals during the conveying of buffer solutions which would promote wear of the seals). In order to assure nondeviating guidance (axis of motion parallel to the stroke axis of the plunger) of the clamping hook 71 even under a load, the latter is guided in the horizontal direction in a close-fitting groove of the housing 99 of the displacement unit and in the vertical direction is supported without tipping via a supporting bulge 73a and a cross pin 74a overhanging it on both sides at the maximum distance. As a result the supporting bulge 73a comes to rest on the base surface of the above-mentioned guide groove and the cross pin on the front surface 74b which is precisely fitted dimensionally to the reference axis, of the corresponding attachment flange (right) on the housing 99 of the displacement unit. The side face of the opposite attachment flange (left) is the counterbearing for the screw 72b which tightens the clamping hook, so that the latter engages a threaded boring on its end face on the side of the supporting bulge. The recess in the fork fitting 71c of the clamping hook 71c which acts on the piston guide sleeve 15, 17 is dimensioned such that the plunger 18 runs in it without touching. The stroke movement of the plunger 18 activates a Z-shaped drive piston 51 (supported at three points) which carries on its front leg 51b a coupling piece 77 provided with two L-shaped holding straps and a central recess for the plunger flange, said coupling piece displaying a ceramic disk 77a as a contact element for the convexly bulging plunger end. A plug spring 76 whose centrally bent legs after engaging the coupling piece 77 press against the flange ring on the piston creates a coupling between the drive piston 51 and the plunger 18 that is free-floating in the radial direction but totally inflexible in the axial direction. Each of the displacement chambers 4, 5 is matched on the inlet side with a valve cartridge 80 (identical and aligned in the same direction). The valve cartridge on the main head 5 (inlet valve) engages with half of its length the inlet module 6 (with a two-way rotary valve or low pressure gradient former) and with the other half engages the receiving boring on the head itself. The second valve cartridge (outlet valve) forms, according to the overhanging type of installation described above, the connecting link between the main head 5 and the subordinate storage head 4 (serial high-pressure arrangement). The receiving borings for the valve cartridges open through fine piercing borings into the displacement chamber borings (T profile penetration). In order to be able to use an identical configuration for the main head 5 and the storage head 4, a dummy cartridge 82 with a simple central boring installed in the semi-overhanging mode, creates the hydraulic connection between the storage head 4 and the outlet module 7 which as a result has a double function when it is equipped with a pressure sensor 10 to monitor the conveying pressure and a spindle valve 12 which upon manual activation makes it possible for the displacement system to be vented. The peripheral seal on all transition sites in the entire liquid path through the displacement system is accomplished with the aid of flange sealing rings made of chemically inert plastic at both end faces of the valve cartridges 80. The mechanical tension necessary for sealing over the entire sandwich arrangement is supplied by a tension screw 98a in the lid element 98 whose flange bars snap into grooves in the housing body 99a. An inlet module 6 fixed via amounting flange also in housing grooves 99b acts as the support. The Z drive piston 51 in FIG. 3 in combination with the cam shaft 50 connected via a transmission to the motor 60 supports the advantages of the displacement unit of the serial pump arrangement 1 in the stacked construction; the drive mechanism 50, 51, 60 is coupled with the displacement unit 1, 3 on the plunger 17, 18; in this case the axis 27 of the stack of the pump arrangement 1 extends out of the plane of the paper, while the stroke movement of the Z drive piston 51--which displays legs 51a, 51b, 51c offset in each case by 90°--of the drive mechanism takes place in the plane of the paper. The stroke movement of the Z drive piston takes place along two guide rods or rails 52a, 52b. On them axial bearings run 53a, 53b, 53c, the one bearing 53b being arranged in the outer region (outside) of the one leg 51b (cross leg on the cam disk side) and mounted on one of the two guide rods 52a, 52b. The cross leg 51a parallel (on the pump side) to the cross leg 51b on the cam disk side represents with its free end the contact with the plunger. At the transition site a plug spring produces a freely floating support for the plunger, i.e. the independent radial alignment during assembly of the piston parallel to the axis of the seal or the piston guide sleeve. The freely floating support assures a joining of the plunger to the Z drive piston without side loads and at the same time facilitates the flanging of the displacement unit 1 on the drive block. The design configuration described is the same for the main piston and the storage piston. Between the two guide rods 52a, 52b--advantageously in the center--opposite forces act on the cross leg 51b on the cam disk side; in one direction the driving force is transmitted via a cam disk 50 and a roll 55 to the cross leg 51 on the cam disk side, in the other direction the force of a compression spring 54 is acting which assures by overcoming the frictional force of the piston seal that the frictional connection between the roll 55 to the Z drive lever 51 and the drive cam disk 50 is preserved during the entire stroke movement. The (different) cam disk profiles for the pistons of the two displacement function units 4,5 operating in series with one another are designed for minimal residual pulsation of the conveyed stream due to the compressibility of the conveyed liquid under certain operating conditions. An electric motor 60 via a--not shown--gear box drives the cam disk (shaft). The rate of conveying is varied by regulating its rpm. The design of the restoring spring 54 assigned to the cross leg 51a of the Z drive piston 51 and the choice of a plug spring 76 for the coupling of the drive piston and the plunger to the opposite leg 51a opens up the possibility of making the entire system extremely small but at the same time mechanically sufficiently stiff. At the same time, assembly is facilitated. The three-point support 53a, 53b, 53c of the Z drive piston 51 described above on the two guide rods 52a, 52b assures the most accurate stroke movement. They also make additional devices for protection against twisting (tilting) unnecessary. The drive elements 50, 51, 55 may be part of a drive block in which the stationary mounting of the guide rods 52a, 52b can easily be accomplished. In this case the possibility exists of mounting the electric motor on the outside for better dissipation of the heat losses. By making slits in the front side of the drive block, then the coupling pieces for the plug springs together bracket the two drive legs 51a to the plungers of the main head 5 and the storage head 4. The entire displacement unit of the serial pump arrangement 1 which is equipped on the outside and with the pump chambers 5, 4 together with the corresponding pistons and piston guide sleeves also with an inlet module (rotary valve/low pressure gradient valve system) and with an outlet module (pressure sensor/venting valve) in this case need only be ranged onto the drive block as a closed structural group and the plungers subsequently coupled to the drive pistons by the plug springs. FIG. 4 shows the clamping device 70 for the piston guide sleeves 15, 16 in which the plungers 17, 18 of the serial pump unit slide in combination with the main head 5 or the storage head 4. These sleeves permit a continuous or discontinuous back rinsing of the piston seals in the main head 5 and in the storage head 4 via connections in order to prevent the formation of salt crystals during the conveying of buffer solutions. The clamping hook 70 presses through a shim ring 7 on the piston guide sleeve 15. This shim ring simultaneously serves as the support ring for the assigned secondary piston seal which assures the dynamic sealing of the rinsing chamber in the piston guide 15 to the outside. The plunger 17 extends through the piston guide sleeve 15 flush with the piston seal into the displacement chamber of the main head 5 or the storage head 4 (liquid conveying function according to the serial pump principle). The axis of the stack is also to be understood as protruding above the plane of the paper. Above the clamping hooks 70, 71 the Z drive piston 51 is shown schematically which is connected with the outer end of the plunger 17 according to the plug spring principle. The freely floating support thus achieved at the coupling site assures a guidance of the plunger free of side loads relative to the installed position of the piston seal. FIG. 4a shows the representation in FIG. 4 in from view, the plunger axes 28, 29 (along the plungers 17, 18) being understood here as protruding out of the plane of the paper. The mounting hook 70, 71 displays an elongated body 70 which passes at one end into an overhanging fork fitting 71. The transition region may be chamfered or slightly shifted. The fork fitting 71--as FIG. 4a shows--with the prongs 71a, 71b forms a groove 71c for the contactless penetration of the plunger 17. With the fork fitting 71 as the counterbearing for the shim ring 7 the guide sleeve 15 is pressed on the function block 4 (here the conveyor head is shown). To press it on the screw 72b is tightened which catches in the clamping hooks 70, 71 via a thread 72a at the rear end of the body 70. The tightening causes the displacement of the clamping hooks 70, 71 parallel to the axis 28 of the piston guide sleeve. To support the parallel moving clamping hook 70 two rest supports 73a, 73b or 74a, 74b are provided. They are arranged off-set with respect to each other both in the longitudinal and in the cross direction of the clamping hook. The bearing 74a is designed as a cross running pin which is pressed between the body 70 and the fork fitting 71 into the clamp hook in the transition zone. The pin ends protruding accordingly on both sides rest on the shoulders of a guide groove 75 for the clamp hook in the main body of the displacement system. The other bearing acts as a slip bearing on which a support bulge or bead 73a protrudes from the body 70 of the clamp hook and can slide on a counterbearing surface 73. The support point of the flat bearing 73a on the sliding surface 73b and the support regions of the pin ends 74a on the shoulders 74b of the receiving and guiding groove 75 are off-set with respect to each other transversely to the axis 28 of the plunger 17. Forces acting by hydraulic loading via the piston seal on the piston guide sleeve 15 can thus not lead to a twisting of the L-shaped clamping hooks 70, 71, since the two spatially shifted supports catch the torque which is created, the two bearings 73, 74 at this time permit an inflexible parallel displacement of the clamping hook with high accuracy which permits a finely adjustable pressing of the guide sleeve over the shim ring 7 at the exit of the displacement chamber boring in the function box 4,5. Behind the clamping arrangement for the piston guide sleeve the stroke movement of the Z drive piston 51 takes place. This stroke movement, the longitudinal displacement of the clamping hooks 70, 71 and the stroke movement of the plunger 17, 18 all take place parallel to one another and transversely to the axis of the stack 27 of the functional components 4, 5, 6, 7. FIG. 5 shows a partially cut-away view as do FIGS. 1 and 2, with schematic emphasis on the plunger 17, 18 and the essence of the sandwich-serial pump arrangement 6, 5, 4, 7 with block disk function carriers arranged in a stack immediately adjacent to one another. Transversely to the stack axis 27 are the axes 29, 28 of the plunger and accordingly also of the displacement chambers 25, 26 in the main head and storage head. The functional units 6, 5 and 5, 4 are connected to one another in a liquid transferring manner by valve cartridges 80, 81 and the functional units 4, 7 by a dummy cartridge 83. Valve cartridges and dummy cartridges are shown schematically in the installed position relative to a milled out recess 83 in the housing body 99 for the sandwich stack with the components 4, 5, 6, 7. The valve cartridges by themselves are closed subunits which may optionally be equipped with one or two ball valves 80b, 80c, 81b. A dummy cartridge 82 with a single through-boring permits the formation of a single connecting channel between two corresponding functional units. The various cartridges are suitable for coupling the functional units stacked on one another in a liquid-tight manner and of aligning them with one another. With half of their length they extend into the central receiving borings provided in the functional elements. In the case of the main head and the storage head these receiving borings open in turn via fine piercing borings into the displacement chamber borings. The valve cartridge 80 shows the configuration of the double outfitting with a miniaturized ball valve--for more sensitive response of the ball even in the case of extremely low conveying rates; the valve cartridge 81 in turn shows the configuration for equipping with a ball valve of larger dimensions. FIGS. 5a and 5b show a basic diagram of the valve cartridges. The ball valves as the basic components preferably consist of a ruby ball and a sapphire/ceramic valve seat with a specially ground sealing edge. As shown in combination with special dimensionally adapted ball stop/ball guide elements and peripheral sealing ring they may consist of chemically resistant plastics in housing sleeves (e. g. of stainless steel or titanium) and can be completed as closed functional units. FIG. 5c shows in cross section a dummy valve cartridge 82 with a central through-boring 82a. This cartridge or connecting sleeve may form a coupling element between the storage head function unit 4 and the vent valve/pressure sensor function unit 7 between which no valve is required but rather a transition piece installed in the fitted seat. FIG. 6 shows in principle an HPLC analysis system which is designed completely in the stacked mode. The above-mentioned functional units 4 through 7 are represented only schematically, where the input module, for example, may be the low pressure gradient former 6a shown by the dotted line. To the gradient former the first valve cartridge 80 (inlet valve) is connected which passes into the main head 5 which operates with the plunger 17 (whose central axis 28 is shown). This is followed in the downstream direction by another valve cartridge 81 (outlet valve) which connects the main head 5 to the storage head 4. In the storage head the plunger 18 is operating (whose central axis 29 is shown). Through the dummy cartridge 82 the conveyed stream passes from the displacement system into the venting valve/pressure sensor module 7 (functions 10 and 12) and from there directly into the sample charging valve function unit 100 with a channel 101 for sluicing the sample to be analyzed into the (eluent) conveyed stream. This functional unit may then also be combined with an automatic sample charging system. Directly coupled to this is the separating column in a special configuration which fits with the concept of the overall structure according to the sandwich principle. The separation column is either constructed as a functional unit of short segments tied into a block which are alternately connected with one another in the narrowest space on the end sides or contain packings of a meandering or spiral structure. The (eluent) conveyed stream passes from the separation column functional unit finally directly into the measurement cell which is uncoupled from the electronic detector part processing the measurement signal for the purpose of substance detection. The basic representation of an optical measurement cell is shown. The measurement cell may also be inserted in a similar manner into an electrochemical detector. In the manner described an instrument is designed which has all the functional units of the wet part of a specific HPLC analysis system in a compact arrangement with the lowest dead volume partly reversing the separation result. At the same time the various functional units can mechanically be held together in a simple way. FIG. 7 shows in an exploded view an example of implementation of the concept of a displacement unit for a serial high-pressure pump in the stacked construction mode illustrating the assembly of the components. The foundation is the four functional units 6, 5, 4 and 7 which are installed in a common receiving boring in a protruding part of the housing body 99. Due to the fact that the receiving boring is opened in several places by slots and borings on the front and to the sides, the functional units used are visually accessible and their installation and removal facilitated. As the supporting base for a mutually liquid-tight holder for the stacked functional units at the upper and lower edge of the receiving boring one finds insertion grooves for a cover plate 98 or for a flange ring 6a on the inlet module 6. Both this module and the storage head unit are connected each via a valve cartridge 81 with the intermediate main head function unit 5 with respect to the liquid flow path and in order to produce an exact mechanical alignment with one another and simultaneously control the conveyed stream in the rhythm of the stroke movement of the plunger in the main head (inlet/outlet valves). The receiving borings for the valve cartridges are designed as flange-collar borings which open into farther-going narrow lumen piercing borings, thus in the displacement chamber boring 25, 26 in the main head and in the storage head. Guide sleeves 15, 16 are pressed against the flattened areas on the function units 4 and 5 in alignment with the piston seals contained in them (high pressure) with a force which compensates for the hydraulic load on the piston seals without yielding under maximal conveying pressure. This is accomplished by means of the clamping hook 70, 71 which, on the one hand, rests with a pin 74a extending on both sides on the shoulder edge of the receiving groove in the region of the attachment flange of the housing body, and on the other, with a support bulge on the opposite end is pressed against the base of the receiving groove when the clamping screw, shown in the loose state, is tightened, which results in longitudinal mobility of the clamping hook exactly parallel to the axis of the drive piston and the plunger. The plungers 18, 19 both in the installed view (bottom: main head 5) and also in the detailed view are shown enclosed by forks 71a, 71b of the supporting fixture on the clamping hooks 70, 71. Functionally viewed the piston executes its strokes without contacting this fork fitting. Behind the clamping hook arrangement 70, 71 the Z-shaped drive piston 51 for the main head is shown, relative to the storage head 4 with the end piece for engaging the plug spring which assures a connection between the drive piston 51 and the plunger 18 that is axially rigid but radially permits a certain deflection. Also shown in detail is the bifunctional outlet module 7 with pressure sensor 10 and air venting spindle valve 12 as well as the inlet module based on a two-way/check valve. From the exploded view one sees that conveying proceeds from bottom to top in the displacement system while all other movement and activation directions, that of the stroke movement of the drive piston and the plunger and the pulling direction of the clamping hooks 70, 71 are transverse to the sleeves of the piston guide but among each other are exactly parallel with one another. From the figure there further emerges the especially advisable simplicity of the design of the sandwich construction in terms of function and operation, relative to the displacement system of a serial pump arrangement. This is also true with respect to the proposed design of the corresponding drive unit and the clamping mechanism for the mutually liquid-fight pairing of the individual functional units and with respect to the aspect of a miniaturized construction. The high pressure pump arrangement in FIG. 1 permits conveying in the pressure range up to 400 bar customarily used in HPLC analytic techniques with high reproducibility even in the microliter conveying range down to 10 μl/min. The arrangement is also basically suitable for any use in which the conveying pressure is above atmospheric pressure.	In order to reduce the overall size of serial pump arrangements, several block-disk-like building elements are used. These building elements are made of a non-metallic material and lie against each other with their control surfaces in a sandwich like stack. Two of the block-disk-like building elements have displacement chambers oriented transversely to the axis of the stack, in each of which is guided a push piston. Inflow and outflow bores in which the high pressure mass flow, for example a chemical buffer, is created, extend parallel to the stack axis. Both building elements form two serially arranged pumping units of the serial pump arrangement and ensure a constant and continuous mass flow. Check valves are provided at the suction and delivery sides of both pumping units. Besides saving space, this arrangement ensures a highly constant and continuous mass flow, as the throughflow paths are as short as possible. The building elements may be made of metal-free but highly stable materials, including sapphire. Because of their shortness a minimal dead volume is obtained, and because of the metal-free materials there is practically no elasticity.	5
TECHNICAL FIELD The invention relates to devices and methods for placing sutures. BACKGROUND INFORMATION Suturing of body tissue is a time consuming aspect of many surgical procedures. For many surgical procedures, it is necessary to make a large opening in the human body to expose the area that requires surgical repair. There are instruments available that allow for viewing of certain areas of the human body through a small puncture wound without exposing the entire body cavity. These instruments, called endoscopes, can be used in conjunction with specialized surgical instruments to detect, diagnose, and repair areas of the body that previously required open surgery to access. Some surgical instruments used in endoscopic procedures are limited by the manner in which they access the areas of the human body in need of repair. In particular, the instruments may not be able to access tissue or organs located deep within the body or that are in some way obstructed. Also, many of the instruments are limited by the way they grasp tissue, apply a suture, or recapture the needle and suture. Furthermore, many of the instruments are complicated and expensive to use due to the numerous parts and/or subassemblies required to make them function properly. Suturing remains a delicate and time-consuming aspect of most surgeries, including those performed endoscopically. Many medical procedures require that multiple sutures be placed within a patient. Typical suturing instruments enable a surgeon to place only one suture at a time. With such suturing instruments, the surgeon is required to remove the instrument from a surgical site and reload the instrument between placing each suture. Further, the surgeon may be required to use forceps or other instruments to help place the suture. In some instances, the forceps or other instruments may require an additional incision to access the surgical site. SUMMARY OF THE INVENTION The invention generally relates to a suturing instrument that can house multiple needle and suture assemblies. The suturing instrument allows a surgeon to place multiple sutures without having to reload the instrument after each suture is placed, which is more efficient and less invasive than a procedure where the surgeon has to remove the instrument from the surgical site to reload. This is particularly helpful when the surgical site is located deep within a body and not easily repeatably accessible. In one aspect, the invention is directed to a suturing instrument including an elongate body member, a first needle, a second needle, and a needle deployment mechanism. The elongate body member includes a distal portion that defines an opening. The first needle and the second needle are disposed within the opening. The needle deployment mechanism is at least partially disposed within the elongate body member and is connectable sequentially to the first needle and the second needle. The needle deployment mechanism moves the first needle and then the second needle out of the opening. In various embodiments, the distal portion may further define a tunnel in communication with the opening. The tunnel may be disposed adjacent the opening, and the second needle and/or additional needles may be disposed within the tunnel. The suturing instrument may also include a needle catch disposed on the distal portion of the elongate body member. The needle catch is configured to receive the first needle and the second needle. The suturing instrument may also include a third needle disposed within the opening and connectable to the needle deployment mechanism. In one embodiment, the needle deployment mechanism includes a needle carrier and an actuator coupled to the needle carrier. The needle carrier may be disposed at least partially within the opening and the actuator may be disposed in a proximal portion of the elongate body member. The needle carrier may include a distal portion that defines a lumen for receiving at least one of the first needle and the second needle. The distal portion of the needle carrier may further define a slot in communication with the lumen for loading a suture. In other embodiments, the second needle transitions from the opening to the lumen after the first needle is deployed from the elongate body member. The first needle and second needle may each include a distal portion and a suture attached thereto. The opening may include a bottom surface defining a slot for loading a suture. In additional embodiments, the elongate body member includes one or more bends. The suturing instrument can be adapted to access remote organs or tissue within a body. The distal portion of the elongate body member may be rotatable relative to a remainder of the elongate body member. Further, the suturing instrument may include a handle disposed opposite the distal portion of the elongate body member. The handle can at least partially house the needle deployment mechanism. The suturing instrument can be used, for example, to access areas within the patient's body to ligate, fixate, or approximate tissue. These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which: FIG. 1A is a schematic plan view of one embodiment of a suturing instrument in accordance with the invention; FIGS. 1B and 1C are schematic cross-sectional views of a proximal portion and a distal portion of the suturing instrument of FIG. 1A ; FIG. 2A is an enlarged cross-sectional view of the distal portion of the suturing instrument of FIG. 1A ; FIG. 2B is a schematic top view of the suturing instrument of FIG. 2A taken at line B—B; FIG. 3A is a schematic plan view of a needle coupled to a suture for use in a suturing instrument in accordance with the invention; FIG. 3B is a schematic perspective view of a needle catch for use with the suturing instrument of FIG. 1A ; FIGS. 4A–4E are partial schematic cross-sectional views of the distal portion of the suturing instrument of FIG. 1A during various operational phases; FIG. 5A is a partial schematic cross-sectional view of a distal portion of a suturing instrument in accordance with another embodiment of the invention; and FIGS. 5B–5F are partial schematic perspective views of the distal portion of the suturing instrument of FIG. 5A . DESCRIPTION FIG. 1A depicts a suturing instrument 100 including a handle 102 , an elongate body member 104 , and a needle deployment mechanism 110 . The suturing instrument 100 also includes a distal portion 106 and a proximal portion 108 . The elongate body member 104 is mechanically coupled to the handle 102 at the proximal portion 108 and the suturing components are ate least partially disposed within the distal portion 106 of the suturing instrument 100 . The handle 102 could take a variety of forms, for example, the handle 102 could be one of the types used with Boston Scientific Corporation suturing systems, in particular the Capio® Push & Catch suturing system. Generally, the needle deployment mechanism 110 extends longitudinally through the elongate body member 104 to the distal portion 106 of the suturing instrument 100 , where the needle deployment mechanism 110 is coupled to a needle 128 ( FIG. 3A ). The needle deployment mechanism 110 moves the needle 128 between a retracted position and a deployed position. The needle deployment mechanism 110 is shown in greater detail in FIGS. 1B and 1C . Referring to FIG. 1B , the proximal portion 108 of the suturing instrument 100 includes the handle 102 , the elongate body member 104 , a suture clip 144 , and the needle deployment mechanism 110 . The suture clip 144 may be coupled to the handle 102 or the elongate body member 104 and is used to hold an end of one or more sutures prior to placement in a patient. The needle deployment mechanism 110 includes an actuator 112 (button 117 , shaft 116 ), a bearing 118 , a button end 119 , and a hole 121 . The bearing 118 rides along a cylindrical surface 105 that is formed by the inside diameter of the elongate body member 104 . A wireform 103 is inserted into the hole 121 , coupling it to the actuator button 117 . A spring 115 encircles the wireform 103 , abuts the button end 119 , and is compressed between the button end 119 and a spring washer 113 . The spring washer 113 is seated upon a center tube 107 . The center tube 107 is housed by the cylindrical surface 105 and is constrained in the distal portion 106 . A pusher wire 111 is attached to the wireform 103 by means of a weld, a coupling, adhesive or other means, and is slidably disposed within a guidance sleeve 109 , the sleeve 109 being disposed within a cylindrical surface 123 formed by the inside diameter of the center tube 107 . In one embodiment, the pusher wire 111 is constructed of nitinol, so chosen for its combination of properties that allow for bendability and high column strength when constrained. Nitinol is a nickel-titanium alloy. Referring to FIG. 1C , the distal portion 106 of the suturing instrument 100 of FIG. 1A includes the elongate body member 104 , the needle deployment mechanism 110 , an articulation mechanism 114 , a curved portion 126 , and a needle catch 122 . Referring again to the needle deployment mechanism 110 , the pusher wire 111 is attached by welding or other means to a coupling 150 , which is slidably disposed within a track 152 . The coupling 150 is attached to a carrier wire 154 , which by virtue of its attachment to the coupling 150 is also slidably disposed within the track 152 . The carrier wire 154 is mechanically coupled to an extendable needle carrier 124 by means of a weld, a coupling, adhesives, or other means. The coupling 150 abuts a backstop washer 156 that is slidably disposed about the pusher wire 111 and is contained within a pocket 160 that includes a back wall 162 , against which the backstop washer 156 rests. The track 152 terminates distally in a pocket 164 that includes a wall 166 . A downstop washer 158 is slidably disposed about the carrier wire 154 and constrained within the pocket 164 . In some embodiments, the suturing instrument 100 may include the articulation mechanism 114 . The articulation mechanism 114 is disposed in the elongate body member 104 proximate the distal portion 106 ( FIG. 1C ). The articulation mechanism 114 facilitates the rotation (in the directions indicated by arrow 182 ) and positioning of the distal end 106 of the suturing instrument 100 . In addition, the elongate body 104 can be substantially linear or may include one or more bends. The articulation mechanism 114 and/or bend(s) can facilitate access to deep and/or difficult to reach areas within the patient. Referring to FIGS. 2A and 2B , the curved portion 126 defines a channel 178 , an opening (or needle exit port 120 ) including a tunnel or (needle compartment 140 ), a needle input/output slot 142 , and a suture slot 146 . The curved portion 126 also defines an opening 176 for receiving tissue ( FIG. 1C ). The curved portion 126 also includes a knot pusher 184 . The needle carrier 124 is disposed within the channel 178 in the curved portion 126 . A distal portion 180 of the needle carrier 124 defines a lumen 138 for holding aneedle 128 a, 128 b, or 128 c (generally needle 128 ). Referring to FIG. 3A , in one embodiment, the needle 128 includes a tip 130 and a shaft 134 coupled to the tip 130 , thereby forming a shoulder 132 . The shaft 134 is coupled to a suture 136 a, 136 b, 136 c (generally suture 136 ). The needle 128 is inserted into the lumen 138 and held by a slight friction fit. The suture 136 extends out of a needle carrier suture slot 148 and the suture slot 146 . Needles 128 b and 128 c are stored in the needle compartment 140 prior to being deployed. Referring again to FIGS. 1B , 1 C, 2 A, and 2 B, in operation, a user (such as a physician or other medical personnel) actuates the needle deployment mechanism 110 by pushing on the button 117 , which via the attachment to the wireform 103 which is attached to the pusher wire 111 , moves the coupling 150 along the track 152 concomitantly moving the carrier wire 154 , which slidably moves the needle carrier 124 through the needle exit port 120 . The user continues to push the button 117 until the needle 128 enters the needle catch 122 . The needle catch 122 , as shown in FIG. 3B , includes openings 170 defined by successive ribs 172 . The needle catch 122 receives the needle 128 (coupled to the suture 136 ) through opening 170 , the ribs 172 deflect slightly to allow the needle 128 to pass through. After the formed shoulder 132 has passed the ribs 172 , the ribs 172 spring back to their original position defining the openings 170 , and the needle 128 remains captured in the needle catch 122 . The user releases the button 117 and the spring 115 urges the button 117 proximally, moving the pusher wire 111 , the coupling 150 , the carrier wire 154 , and the needle carrier 124 proximally along with the button 117 to the retracted position. As the needle carrier 124 moves back to the retracted position, the needle 128 slides out of the lumen 138 . The openings 170 are chosen to be smaller in dimension than the formed shoulder 132 . This causes the needle catch 122 to retain the needle 128 because the flat rear surface of the shoulder 132 prevents the needle 128 from passing back through the opening 170 . When it is necessary to remove the needle 128 from the needle catch 122 , the needle 128 may be moved toward an enlarged portion 174 of opening 172 . The enlarged portion 174 is sized to allow the formed shoulder 132 to pass through without resistance. The needle catch 122 is preferably constructed of thin stainless steel of high temper, such as ANSI 301 full hard. The needle catch 122 may be fabricated by means of stamping, laser machining, or chemical etching. The suturing instrument's component materials should be biocompatible. For example, the handle 102 , the elongate body member 104 , and portions of the needle deployment mechanism 110 may be fabricated from extruded, molded, or machined plastic material(s), such as polypropylene, polycarbonate, or glass-filled polycarbonate. Other components, for example the needle 128 , may be made of stainless steel. Other suitable materials will be apparent to those skilled in the art. The material(s) used to form the suture should be biocompatible. The surgeon will select the length, diameter, and characteristics of the suture to suit a particular application. Additionally, the mechanical components and operation are similar in nature to those disclosed in U.S. Pat. Nos. 5,364,408 and 6,048,351, each of which is incorporated by reference herein in its entirety. Referring to FIGS. 2A–2B and 4 A– 4 E, the present invention enables a user to place multiple sutures 136 in a patient without removing the suturing instrument 100 from the patient. The user loads the suture 136 c through the first suture slot 146 a until the suture 136 c emerges from the second suture slot 146 b. The user then inserts the needle 128 c through the needle input/output slot 142 into the needle compartment 140 . The user repeats this process for additional sutures 136 and needles 128 . The user can repeat this process for loading the first suture 136 a and the first needle 128 a, or the user can insert the first needle 128 a directly into the needle carrier 124 . In either case, the sutures 136 a, 136 b, 136 c extend out of the second suture slot 146 b. If the needle 128 a is loaded into the needle compartment 140 , the user pulls on the first suture 136 a (held by the suture clip 144 ) to cause the first needle 128 a to slide down an inclined needle shelf 204 and out of the needle compartment 140 through the needle output slot 142 into the lumen 138 of the needle carrier 124 . The suture 136 a extends out of the needle suture slot 148 and the second suture slot 146 b. In another embodiment, the suture 136 a could be pulled by attaching the suture 136 a to a spool mounted on the elongate body member 104 and winding the spool. In still other embodiments, the suture 136 a could be pulled by other mechanical means known in the art, such as by a lever, for example. After the needles 128 a, 128 b, 128 c and sutures 136 a, 136 b, 136 c are loaded into the suturing instrument 100 , portions of the sutures 136 a, 136 b, 136 c extending out the suture slot 146 b are held by the suture clip 144 ( FIG. 1B ). The needle carrier 124 , which is part of the needle deployment mechanism 110 , is sequentially connectable to the needles 128 stored in the needle compartment 140 . This means that each needle 128 stored in the needle compartment 140 is connected to, and then deployed by, the needle carrier 124 one at a time in the order the needles 128 are dispensed from the needle compartment 140 . The user then inserts the elongate body member 104 into a patient and orients the elongate body member 104 so that the needle exit port 120 is proximate to or in contact with the tissue 206 to be sutured. The user then pushes the button 117 ( FIG. 1B ), as described above. Pushing the button 117 causes the needle carrier 124 (holding the first needle 128 a ) to extend out of the needle exit port 120 and push the needle 128 a through the tissue 206 . As the first needle 128 a is pushed through the tissue 206 , the first needle 128 a pulls the first suture 136 a through the tissue 206 . As the user continues to push the button 117 , the needle carrier 124 continues to advance out of the needle exit port 120 and directs the first needle 128 a and the first suture 136 a toward the needle catch 122 . The user continues to push the button 117 until the first needle 128 a contacts and becomes captured by the needle catch 122 ( FIG. 4B ). The user then retracts the needle carrier 124 by releasing the button 117 , as previously described. After the user retracts the needle carrier 124 , the first needle 128 a and the first suture 136 a are left captured within the needle catch 122 , with the first suture 136 a extending through the tissue 206 ( FIG. 4C ). When the needle carrier 124 returns to a fully retracted position, the user pulls on the second suture 136 b to cause the second needle 128 b to slide down the inclined needle shelf 204 and out of the needle compartment 140 through the needle input/output slot 142 and into the lumen 138 of the needle carrier 124 . The second suture 136 b extends out of the needle carrier suture slot 148 and the second suture slot 146 b. The user then advances the needle carrier 124 as described above until the second needle 128 b is captured by the needle catch 122 ( FIG. 4D ). The user then retracts the needle carrier 124 as described above leaving the second needle 128 b and the second suture 136 b captured by the needle catch 122 ( FIG. 4E ). This procedure can be repeated for the third needle 128 c, or for as many needles as may be stored in the needle compartment 140 . After one or more sutures 136 have been placed, the user withdraws the suturing instrument 100 from the patient. The user detaches the suture(s) 136 from the needle(s) 128 and ties a knot or knots into the suture(s) 136 . The user can then use the knot pusher 184 to push the knot(s) into the patient as the knot(s) is tightened. Referring to FIGS. 5A–F , in an alternative embodiment, the distal portion 106 of the suturing instrument 100 includes a curved portion 200 . The curved portion 200 defines a needle compartment 188 , a needle output slot 190 , a needle loading slot 192 , a first suture slot 196 ( FIG. 5B ), and a second suture slot 198 . In this embodiment, a needle 128 a is inserted into the needle carrier 124 with a suture 136 a extending through the needle carrier suture slot 148 , the first suture slot 196 and the second suture slot 198 . An additional needle 128 b is inserted into the needle compartment 188 through the needle loading slot 192 with a suture 136 b —extending through the first suture slot 196 and the second suture slot 198 ( FIG. 5B ). In operation, this alternative embodiment functions largely the same way as the embodiment previously described. The user advances the needle carrier 124 by pressing the button 117 ( FIG. 1A ) until the first needle 128 a along with the first suture 136 a is driven through the tissue and captured by the needle catch 122 ( FIG. 5D ). After the needle 128 a and the suture 136 a are captured in the needle catch 122 , the needle carrier 124 is retracted so that the second needle 128 b can be loaded into the needle carrier 124 ( FIG. 5E ). When the needle carrier 124 is fully retracted, the user pulls the second suture 136 b causing the second needle 128 b to slide into the needle carrier 124 from the needle compartment 188 through the needle loading slot 190 . The user again advances the needle carrier 124 out of the needle exit port 120 , through the tissue, and into the needle catch 122 ( FIG. 5F ). The user then retracts the needle carrier 124 leaving the needle 128 b and coupled suture 136 b captured by the needle catch 122 . In other embodiments, more needles 128 and sutures 136 can be loaded into the needle compartment 188 . Other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. The described embodiments are to be considered in all respects as only illustrative and not restrictive.	A suturing instrument including multiple needle and suture assemblies that are at least partially disposed within the suturing instrument allows a surgeon to place multiple sutures intercorporally without having to remove the instrument from a surgical site and reload the instrument between placing each suture. The suturing instrument includes an elongate body member that includes a distal portion defining an opening. The suturing instrument further includes a first needle disposed within the opening, a second needle disposed within the opening, and a needle deployment mechanism disposed at least partially within the elongate body member and connectable sequentially to the first needle and the second needle.	0
BACKGROUND OF THE INVENTION This invention relates to a process for fabricating semiconductor integrated circuit devices capable of high packing density and high-speed operation. Emitter-coupled logic (ECL) bipolar semiconductor integrated circuit devices, also known as current-mode logic (CML) devices, have commonly been used in semiconductor integrated circuit application fields requiring especially high speed. In an ECL or CML circuit, for a given power consumption and logic swing, the propagation delay time is mainly determined by the parasitic capacitance of the circuit elements and interconnection wiring, and the base resistance and gainbandwidth product of the transistors. To reduce parasitic capacitance, in particular the base-collector junction capacitance of transistors which make a large contribution to operating speed, it is customary to use polysilicon to lead the base electrode outside the element region thereby to reduce the base region, and to form the polysilicon resistors and metal interconnections on a thick isolation oxide. To reduce the base resistance, it is necessary to reduce the resistance of the inactive base layer, dispose it as close as possible to the emitter, reduce the width of the emitter, and reduce the resistance of the active base layer under the emitter. Means of improving the gainbandwidth product include making the base and emitter junctions shallow and the epitaxial collector layer thin. A fabrication process that has been proposed to achieve these goals is described in Japanese Patent Application Publication No. 131698/1986 and a corresponding U.S. patent application Ser. No. 057,510 filed June 3, 1987, now U.S. Pat. No. 4,735,912. The steps in this fabrication process are illustrated in FIG. 2A to FIG. 2E, which trace the formation of the cross section of a transistor with a double-base structure, in which base electrodes are located on both sides of the emitter to reduce the base resistance. FIG. 2A shows the state after oxide isolation process has been carried out and the polysilicon and selective oxidation mask have been formed. The parts labeled are a P - type silicon substrate 1, an N + -type buried layer 2, an N - -type epitaxial layer 3, an isolation oxide layer 4, an N + -type region 5 for reducing the collector resistance, the polysilicon 6, a nitride film 7 that will become the selective oxidation mask, and a boron-doped layer 8 formed using the nitride film 7 and its patterning resist (not shown in the drawing) as a mask. The polysilicon 6 is selectively oxidized and the nitride film 7 is removed, then the surface of the remaining polysilicon 6 is oxidized, giving the structure shown in FIG. 2B. In this structure the electrodes of the transistor are formed by the polysilicon regions 6a to 6d, which are isolated from one another by an oxide film 9. The boron-doped layer 8 is diffused by heat treatment during this process and becomes a moderate-doped p-type layer forming part of the inactive base. Next, using a resist not shown in the drawing, a high-dosage implant of boron ions is performed on the polysilicon regions 6a and 6c that will become the base electrodes. After the resist is removed, the entire surface is given a low-dosage boron ion implant. This is followed by heat treatment in a non-oxidizing atmosphere, forming a heavily-doped inactive base 10 and an active base 11 by diffusion from the polysilicon as shown in FIG. 2C. These base regions 10 and 11 are linked by the region 8, which is doped at a moderate concentration. Next contact holes are opened as in FIG. 2C and a slight oxidation is performed on the polysilicon exposed at the contact holes as shown in FIG. 2D. Then, using a mask not shown in the drawings, arsenic ions are implanted into the polysilicon regions 6b and 6d and heat treatment is performed to form the emitter 12. Next the thin oxide is removed and metal electrodes 13a to 13d are formed. With this process it is possible to form shallow junctions of the active base 11 and the emitter 12 and obtain a fairly high-performance transistor. It is not possible, however, to reduce the base resistance as much as desired because the heavily-doped inactive base 10 and the emitter 12 are separated by the moderately-doped base 8, and resistance in this region cannot be made adequately low. Furthermore, the heat treatment in the selective oxidation of the polysilicon extends the moderately-doped base 8 under the emitter 12, narrowing the active base 11. This leads to considerable recombination of the carriers injected into the base from the emitter, making it difficult to increase the current gain. This tendency worsens at reduced feature sizes, imposing a limit on the shrinkage of the transistor geometry. Also, since the moderately doped base 8 has a deep junction, there are limits to the thinning of the epitaxial layer, creating an obstacle to improvement of the gain-bandwidth product. All of the problems described above can be ascribed to the moderately-doped base 8. SUMMARY OF THE INVENTION An object of the present invention is to eliminate these problems in the reduction of the base resistance, reduction of junction capacitance, enhancement of current gain, and improvement of gain-bandwidth product, and provide a process for the fabrication of semiconductor integrated circuit devices that are small in size and excel in high-speed operation. In the semiconductor integrated circuit fabrication process of this invention, the base electrode is formed by selective oxidation of polysilicon deposited on a silicon substrate. This polysilicon is heavily doped with boron. The polysilicon oxide is removed from the emitter region to form an opening there and the exposed substrate surface is oxidized and a heavily-doped inactive base is formed by diffusion from the polysilicon. An active base is formed adjacent to the inactive base by boron ion implantation. Next a chemical vapor deposition (CVD) layer is grown over the whole surface, then etched by reactive ion etching to leave the CVD layer on the sidewall of the opening. An emitter window is opened using the CVD layer on the sidewall as a mask, and the emitter is formed in the active base by diffusion from arsenic doped polysilicon. In this invention the base resistance is reduced because the heavily-doped inactive base is close to the emitter, an the base-collector junction capacitance is reduced because the base area is reduced in size. This reduction of the junction capacitance also reduces all the time constants, and improves the gain-bandwidth product. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A to FIG. 1F illustrate the fabrication process in an embodiment of this invention. FIG. 2A to FIG. 2E illustrate the fabrication process of the prior art. DETAILED DESCRIPTION OF THE EMBODIMENTS An embodiment of this invention will be described with reference to the drawings. FIGS. 1A to 1F illustrate the fabrication steps in this embodiment. First, as shown in FIG. 1A, after the oxide isolation step, 2000 Å to 3000 Å of polysilicon 6 are formed on a silicon substrate 1 in which an N + -type region 5 has been formed. The surface of the polysilicon 6 is oxidized to a thickness of about 200 Å, and a nitride film 7 1000 Å to 2000 Å thick is formed selectively in the portions at which the base electrode will be formed. Next the polysilicon 6 is selectively oxidized as in FIG. 1B, forming polysilicon regions 6a and 6c that are linked each other like a ring (Surrounding a polysilicon oxide 9). Boron ions are implanted in polysilicon regions 6a and 6c through the nitride film 7 at a dosage of 10 15 cm -2 to 10 16 cm -2 . Next, as shown in FIG. 1C, the oxide 9 is selectively removed to form openings exposing the surface of the silicon substrate 1 at the regions that will become the emitter and collector. (Actually it is the surface of the N + region 5 etc. that is exposed.) These surfaces and the exposed surfaces of the polysilicon regions 6a and 6c are thermally oxidized to form an oxide film 14 approximately 1000 Å thick. This process also diffuses boron from the polysilicon regions 6a and 6c to form a heavily-doped inactive base 10. Next boron ions are implanted through the oxide film 14 at a dosage of 1 to 5×10 13 cm -2 ; and annealing is performed to form an active base 11 adjacent to the inactive base 10 as in FIG. 1D, and a chemical vapor deposition (CVD) layer 15 of nitride film 1000 to 2000 Å thick is formed on the entire surface. This CVD layer 15 is next etched by reactive ion etching. The CVD layer 15 remaining on the sidewall of the opening where the emitter will be formed acts as a mask for subsequent etching of the oxide film 14 to form the emitter window. The window for the collector contact is also opened at this time, giving the structure shown in FIG. 1E. Next an arsenic-doped polysilicon layer 16 is created, 2000 Å to 4000 Å thick. Thermal oxidation is performed to form an oxide layer 17 and arsenic is diffused simultaneously to form the emitter 12. Finally, contact holes are opened and the metal electrodes 13a to 13d are formed in FIG. 1F. In this embodiment the CVD layer 15 was a nitride layer, but polysilicon could be used instead, or a compound layer could be used consisting of a nitride or polysilicon layer overlying a thin oxide layer. This last arrangement can prevent over-etching since the thin CVD oxide layer acts as a stopper for reactive ion etching of the upper layer. This compound layer is suitable for obtaining a narrow emitter, because the width of the emitter window can be easily controlled by varying the thickness of the upper layer. This invention also permits other variations in the embodiment described above: for example, the formation of the active base 11 in the process in FIG. 1D can be omitted to create a static induction transistor. As described above, the fabrication process of this invention reates the emitter in a selectively oxidized polysilicon region, with the heavily-doped inactive base formed by diffusion from the polysilicon remaining next to the oxidized region, so the space between the heavily-doped inactive base and the emitter can be greatly reduced and an emitter with a narrow width can easily be formed. The base resistance can therefore be reduced much more than before. In the prior art, when the widths of the emitter, the moderately-doped base, and the heavily-doped inactive base were all the minimum feature size, the width of the entire base region was five times the minimum feature size; in this invention it is only three times the minimum feature size. The base-collector junction capacitance is thus reduced to about 60% the previous level. Furthermore, in the prior art there was a large junction contact area between the emitter and the moderately-doped base, whereas in this invention all or almost all of the base-emitter junction is a junction between the emitter and the lightly-doped active base, so the emitter can be smaller in width than before, and the emitter-base junction capacitance is reduced. Also, in the prior art the depth of the moderately-doped base junction limited the thinning of the epitaxial layer, but in this invention there is no such deep junction, so the epitaxial layer can be made as thin as lum or less, reducing the transit time of carriers in the collector depletion region. The reduction of the junction capacitance seen above also reduces the collector and emitter time constants, and all these factors serve to improve the gain-bandwidth product. This invention, accordingly, reduces the base resistance and parasitic capacitance of the transistor, improves the gain-bandwidth product, and therefore enables extremely high-speed operation. In the prior art, because the moderately-doped base extended below the emitter, reduction of the feature size reduced the ratio of the active base area to the emitter area, making it difficult to obtain a high current gain, but in this invention there is almost no intrusion of the inactive base below the emitter, so a high current gain can be obtained and the feature size can easily be reduced. In the prior art the entire surface of epitaxial layer is doped with boron, so a special step is required to create a lateral PNP transistor, but in this invention if the polysilicon 6a and 6c are separated and the oxide between the polysilicon regions is not removed (see FIG. 1B and FIG. 1C), a lateral PNP transistor is formed automatically using exactly the same process as for an NPN transistor. As seen above, this invention is widely applicable to high-speed semiconductor integrated circuit devices with high packing density. It can greatly increase the operating speed of ECL/CML circuits, and can be used in TTL circuits and analog (linear) circuits which employ large numbers of lateral PNP transistors.	In a process for fabricating a semiconductor integrated circuit, a polysilicon layer deposited on the working surface of a silicon substrate is selectively oxidized and the polysilicon oxide layer is partially removed to form an opening. A chemical vapor deposition layer is formed on the entire surface and anisotropic etching of said chemical vapor deposition layer is performed to leave the chemical vapor deposition layer on the sidewall of the opening.	7
FIELD OF THE INVENTION The present invention relates to a refrigerator, and particularly to a vegetable box cooling apparatus for a refrigerator, in which the cool air within the vegetable box is forcibly circulated, thereby speedily and uniformly cooling the vegetables within the vegetable box, and making it possible to store the vegetables in a fresh state for a long time. BACKGROUND OF THE INVENTION In most conventional refrigerators as shown in FIG. 5, the cool air which is introduced into a refrigerating room 11 is circulated within a vegetable room 12 by means of a blowing fan 10 so that a vegetable box 20 is indirectly cooled. Such a method of cooling is not very effective, and, in an attempt to give a solution to this problem, there was proposed another vegetable box cooling apparatus. This apparatus is proposed in Korean Utility Model Laid-Open No. 90-7062, and is constituted as described below. That is, a projected front portion with a plurality of cool air passing holes formed thereon is provided on a frontal plate of the vegetable box, and an upper flange portion is formed vertically relative to the projected front portion and integrally with it. Further, a plurality of engaging protuberances are projected in the horizontal direction from the outer surface of the upper flange portion, while a gasket of a proper shape is installed on the upper flange portion, thereby making the cool air within the refrigerating room smoothly circulate around the vegetable box. Meanwhile, Japanese Utility Model Laid-Open No. 55-8805 discloses another vegetable box cooling apparatus. In this apparatus, a part of the cool air which is supplied into the refrigerating room is introduced through a cooling duct installed on the wall of the vegetable room into the vegetable room. Further, still another apparatus is disclosed in Japanese Utility Model Laid Open No. 1-91871. In this apparatus, a temperature sensor is installed on the vegetable box, and a damper which is selectively opened or closed by control signal transmitted from a controller (not shown) is installed on a vegetable box passage which is formed around the vegetable box, so that the damper should be able to selectively supply or cut off the cool air to and from the vegetable room or the vegetable room passage. In the above described conventional apparatuses, the vegetable room and the vegetable box are almost sealingly divided , and the vegetables within the vegetable box are indirectly cooled through the surrounding walls of the vegetable box, with the result that there occurs temperature difference between the vegetable room and the vegetable box. Particularly, in the initial operating stage of the refrigerator, the cooling speed of the vegetable box is very slow, and therefore, speedy cooling of vegetables becomes difficult. Further, during the operation after the initial operating stage of the refrigerator, the internal temperature of the vegetable box is maintained higher than that of the vegetable room, with the result that the stored vegetables are severely dried or degenerated, thereby making it impossible to store vegetables in a fresh state for a long time. SUMMARY OF INVENTION The present invention is intended to overcome the above described disadvantages. Therefore it is an object of the present invention to provide a vegetable box cooling apparatus for refrigerator, in which the cool air within the vegetable box is forcibly circulated, so that the stored vegetables can be speedily cooled by improving the thermal transfer efficiency, and that it should be made possible to store vegetables in a fresh state for a long time by maintaining the internal temperature of the vegetable box within a certain temperature range. In achieving the above object, the vegetable box cooling apparatus according to the present invention comprises a refrigerator body including a freezing room, a refrigerating room, and a vegetable room partitioned from each other, and provided with a blowing fan in order to circulate the cool air; a vegetable box pivotally installed within the vegetable room so as for vegetables to be stored, and having a cool air inlet and a cool air outlet; a cool air sucking member curvedly formed on and across the bottom of the vegetable box and integrally with it, and connected to the cool air outlet of the vegetable box so as for the cool air of the interior of the vegetable box to be sucked thereinto; a cool air circulating member installed on a recess of the rear wall of the vegetable room, and provided with a fan motor and a blower enabling cool air to be circulated; a duct member for receiving the blower, and for connecting the cool air inlet and the cool air outlet; and first and second temperature sensing means for sensing the temperatures of the refrigerating room and the vegetable room in order to transmit control signals to a controller to enable the cool air circulating member to be turned on and off. During the operation of the apparatus of the present invention constituted as described above, if the internal temperatures of the refrigerating room and the vegetable room reach pre-set levels by the help of the functions of the first and second temperature sensing means, then the cool air circulating member is turned on by a controller (not shown). At the same time, the cool air of the refrigerating room is forcibly circulated through a duct member and the cool air sucking member (installed within the vegetable box), thereby improving the heat transfer efficiency within the vegetable box, and making it possible to speedily cool the vegetables. Further, the internal temperature of the vegetable box can be maintained within a predetermined temperature range which is almost the same as the temperature of the refrigerating room, thereby making it possible to store vegetables in a fresh state for a long time. BRIEF DESCRIPTION OF THE DRAWINGS The above object and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which: FIG. 1 is a schematic sectional side view showing the lower structure of the refrigerator adopted for the present invention; FIG. 2 is a partly cut-out perspective view of the vegetable box according to the present invention; FIG. 3 illustrates the operating system of the fan motor according to the present invention; FIG. 4 graphically illustrates comparisons of the temperature of the vegetable box of the present invention with that of the conventional refrigerator, in which: FIG. 4a graphically illustrates the temperature variation of the vegetable room at the initial operating stage; FIG. 4b graphically illustrates the temperature variations of the vegetable room and the refrigerating room during the operation of the conventional refrigerator; and FIG. 4c graphically illustrates the temperature variations of the vegetable room and the refrigerating room during the operation of the refrigerator according to the present invention; and FIG. 5 is a schematic sectional side view of the conventional refrigerator. DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 illustrate an embodiment of the present invention, and as shown in these drawings, a vegetable room 12 is formed in the lower portion of a refrigerating room 11 of a refrigerator body 1. A vegetable box 2 is pivotally installed in a sealed state within the vegetable room 12, and the refrigerating room 11 and the vegetable room 12 are isolated from each other by means of a partition 13, while an opening 13' is formed on the rear end of the partition 13 so as for the cool air to be supplied from the refrigerating room 11 toward the vegetable room 12. The cool air which is introduced through opening 13, is circulated through the vegetable room 12, and then, the cool air returns through the front portion into the refrigerating room 11. Through the repetitions of such cycles, the vegetable box 2 is indirectly cooled. About the middle of the rear wall of the vegetable box 2, there are formed a cool air inlet 21 and a cool air outlet 21, separated vertically from each other. Further, a cool air sucking member, or channel 22 provided with a plurality of through-holes 22a on the opposite walls thereof is integrally formed across the bottom of the vegetable box 2, with a rear end 22b of the cool air sucking member 22 being connected to the cool air outlet 21', so that the cool air sucking member 22 should be able to suck the cool air within the vegetable box 2 and discharge it through the cool air outlet 21'. Further, a recess 12' is formed at a proper position on the rear wall of the vegetable room 12' and a blower 31 is installed in the recess 12', so that the blower 31 should be able to forcibly circulate the cool air upon being rotated by a fan motor 3. In front of the recess 12', there is installed a duct 4 for receiving the blower 31. A suction hole 41 which is led to the cool air outlet 21' of the vegetable box 2 is formed at the lower end of the duct 4, while a discharge hole 41' which is led to the cool air inlet 21 of the vegetable box 2 is formed at the upper end of the duct 4. Further, corrugated tubes 42, 42' which are contractable and extendable are connected between the cool air outlet 21' and the suction hole 41' and between the cool air inlet 21 and the discharge hole 41' respectively in order to connect them in an air-tight state. Meanwhile, a first temperature sensor 5 which is for sensing the internal temperature t1 of the refrigeration room 11 is installed at a proper position on the rear wall of the refrigerating room 11, while a second sensor 5' which is for sensing the internal temperature of the duct 4, i.e., the internal temperature t2 of the vegetable box 2 is installed at a proper position on the upper portion of the duct 4. As shown in FIG. 4, these first and second temperature sensors 5,5' detect the temperature t1 of the refrigerating room 11 and the temperature t2 of the vegetable box 2 respectively in order to output sensing signals to a controller (not shown). Thus if the controller (not shown) finds that the difference (t2-t1) between the temperatures t1 and t2 reaches a certain pre-set value, the controller (not shown) outputs a control signal in order to activate the fan motor 3, so that the internal air of the vegetable box 2 should be circulated by the blower 31. The apparatus of the present invention constituted as above will now be described as to its operations and effects. As shown in FIG. 3, the first and second temperature sensors 5,5' detect the internal temperature t1 of the refrigerating room 11 and the internal temperature t2 of the vegetable box 2, i.e., the internal temperature of the duct 4 respectively in order to output sensing signals to the controller (not shown). Under this condition, if the difference (t2-t1) between the temperatures t1,t2 reaches a certain pre-set value, i.e., 2° C. in the present embodiment, a control signal is outputted from the controller (not shown) in order to drive the fan motor 3, so that the blower 31 should be activated in order to circulate the internal air of the duct 4. Owing to the pressure difference generated by the operation of the blower 31, the internal air of the vegetable box 2 is sucked through the through-hole 22a of the air sucking member 22 into the duct 4, and then, introduced through the cool air outlet 21' and the suction hole 41 of the duct 4 into the interior of the duct 4. Then the air is returned through the discharge hole 41' and the cool air inlet 21 into the vegetable box 2, thereby forcibly circulating the air within a closed circuit. Therefore, a heat transfer, is carried out in the form of conduction and natural convection through a thermal boundary layer formed on the interior and exterior surfaces of the walls of the partition 13 or the vegetable box 2. The cool boundary air is allowed to continuously flow in a forcible manner into the circulating air toward the cool air sucking member 22, with the result that the heat transfer efficiency is improved during the heat transfer through the thermal boundary layer. Therefore the rate of the heat transfer to the vegetable box 2 is increased, and, the internal temperature t2 of the vegetable box 2 is speedily lowered compared with the case of the conventional refrigerators as shown in FIG. 4a, thereby cooling vegetables very speedily. Under this condition, if the temperature difference (t2-t1) shows to be less than 2° C., then a control signal is outputted from the controller (not shown) in accordance with the sensing signals from the first and second temperature sensors 5,5' in order to stop the driving of the fan motor 3, so that the driving of the blower 31 should be terminated. Meanwhile, if the temperature difference (t2-t1) is 2° C. or more, then the blower 31 is activated in the above described manner in order to forcibly circulate the internal cool air of the vegetable box 2 continuously, so that the internal temperature t1 of the refrigerating room 11 or the vegetable room 12 and the internal temperature t2 of the vegetable box 2 can be maintained within a certain range. That is, as shown in FIG. 4c, a cooling operation can be carried out in such a manner that there should be almost no temperature difference between the temperature t1 of the refrigerating room 11 and the internal temperature t2 of the vegetable box 2, thereby achieving a uniform cooling. According to the present invention as described above, the internal cool air of the vegetable box is forcibly circulated, so that the heat transfer from the refrigerating room or the vegetable room into the vegetable box should be enhanced, thereby making it possible to speedily cool vegetables. Further, owing to the forced circulation of the cool air, the internal temperature of the vegetable box can be maintained at almost the same level as that of the refrigerating room or the vegetable room, so that vegetable should not be easily dried or degenerated, thereby making it possible to store vegetables in a fresh state for a long time.	A refrigerator includes a refrigerating room, a vegetable room, and a vegetable box movably disposed in the vegetable room. The vegetable box includes an air inlet and an air outlet. A duct disposed on a wall of the vegetable box interconnects the air inlet and air outlet. A blower disposed in the duct circulates air from said outlet to said inlet. The duct carries seals which form air seals around the inlet and outlet when the vegetable box is closed. Temperature sensors automatically turn the blower on and off. A channel extends along a wall of the vegetable box and includes through-holes. The channel communicates with the air outlet.	5
BACKGROUND—FIELD OF INVENTION [0001] This invention belongs to recreational snowmobile vehicles particularly the ones having one or more skis, and particularly snow ski provided with at least a wear runner and also a blade. This patent proposes a modification to the blade to increase the ski response in soft snowy path to procure an aggressive driving. Furthermore, the invention comprises a modification to a central runner which is self sharpening. BACKGROUND—DESCRIPTION OF THE PRIOR ART [0002] The present invention is an improvement over four inventions from the same inventor so being utilized by other snowmobile skis comprising the same essential characteristics: at least a wear runner and at least a blade. The prior patents from the same inventor which the present invention refers to are the following: CA 2,388,833; Snowmobile runner. CA 2,378,638; Snowmobile ski auto-stabilizer, in M or reversed W. CA 2,388,801; Concave ski stabilizer. [0006] CA 2,300,359 and U.S. Pat. No. 6,520,512; snowmobile ski stabilizer comprising a reversed U channel and a Teflon™ corrector lining the web of the U-channel to provide smooth gliding of the snow between the wings of the U-channel. Centrally of the wings is disposed an existing carbide runner which may be replaced by a self adjusting runner. [0007] A review of the prior art revealed the following patents: U.S. Pat. No. 5,344,168 Olson Sep. 6 th 1994; shows a wear runner 50 provided with a carbide bar 56 of the shape of a triangular diamond. The carbide resists until its point 58 is worn more than 10% after which time it does not behave with sufficient sharpness to engage itself into sharp ice, whence the danger of side swaying, the sharp point being dull from wear and incapable of stopping swaying. [0009] CA 2,195,166; shows a wear runner 26 supported in 64, 66, 68 but without added carbide. The element which does the cutting is a break blade 152 which again when dull may no longer cut into the ice. [0010] U.S. Pat. No. 6,012,728; is a snowmobile ski with multiple protruding keels on its underside. The height of the steering keel gradually increases in protrusion, from front end to a central position and may reduce from central position to aft end, but is not high enough to really penetrate snow. OBJECTIVES [0011] During fast turns of snowmobile skis comprising at least one wear runner and one blade, the snow pressure increases because of the presence of a central wear runner. This phenomenon creates a tendency to lift up the ski during high speed turns. The objective of the present invention is to provide an exit door to the snow by making an aperture in the blade opposite the runner The snow submitted to pressure from the runner gets out by the aperture and the ski no longer tends to lift up by excessive snow pressure. Meanwhile, the adherence of the blade during fast turns and the driving are so improved under these circumstances. To make this aperture useful it must be made oppositely to the wear runner. The wear runner refers to a runner supporting the ski and the snowmobile during passages over a hard surface. The wear runner is obligatory lower than the blade. During passage on a hard surface it is the wear runner that gets into contact with the ground, not the bottom of the blade. The aperture in the blade must be made oppositely to the wear runner otherwise if the blade were to touch a hard surface at a spot (for example a railroad track), the blade would get stuck in the aperture. Being opposite to the wear runner, the edges of the aperture do not touch the hard surface for it is the wear runner which is in contact with the hard surface. A second objective of the invention is that the wear runner be self sharpening, more particularly comprising a rectangular central blade embedded at the center of a support also rectangular and having parallel sides, the hardness of the support being inferior to the hardness of the blade so when the blade slides over a hard surface such as asphalt road, the support is prevented from wearing as long as the carbide resists. During passage in abrasive paths, the support wears more rapidly than the central carbide leaving a difference in height between the blade and the support over all the depth of the wear runner, making it self sharpening, always at a same degree, until the end of the wear out of the runner. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The present invention will be further understood from the following description with reference to the drawings in which: [0013] FIG. 1 is a perspective of a runner of the prior art. [0014] FIG. 2A is a perspective of a constant use runner [0015] FIG. 2B is a side view of FIG. 2A with partial slit. [0016] FIG. 3 is a cross-section according to line 3 - 3 of FIG. 1 . [0017] FIG. 4 is a cross-section according to line 4 - 4 of FIG. 2A [0018] FIG. 5 is a perspective of a ski equipped with a stabilizer. [0019] FIG. 6 is a side view of an aggressive stabilizer. [0020] FIG. 7 is a bottom view of a diagram of the ski of FIG. 6 . [0021] FIG. 8 shows a perspective of the aggressive of FIG. 6 . [0022] FIG. 9 shows an embodiment of the invention with a concave ski. [0023] FIG. 10 shows two independent blades and a central runner. [0024] FIG. 11 shows two blades and a runner made of one only piece. [0025] FIG. 12 is a section of a stabilizer adapted to a concave ski. [0026] FIG. 13 is a perspective of a concave ski having a stabilizer. [0027] FIG. 14 is a perspective of a ski with blades and a runner. [0028] FIG. 15 is a top view of the ski of FIG. 14 . [0029] FIG. 15 . 1 is a section according to line 15 . 1 - 15 . 1 of FIG. 15 ; [0030] FIG. 15 . 2 is a section according to line 15 . 2 - 15 . 2 of FIG. 15 . [0031] FIG. 15 . 3 is a section according to line 15 . 3 - 15 . 3 of FIG. 15 . [0032] FIG. 16 is a perspective of a replaceable runner. [0033] FIG. 17 is a section according to line 17 - 17 of FIG. 16 [0034] FIG. 18 is a perspective of a runner seen from underneath. DESCRIPTION OF THE PREFERRED EMBODIMENT [0035] Preferred embodiments of the invention are illustrated in the figures wherein the same numbers identify the same characterizing elements. [0036] FIG. 1 shows an original runner 20 provided underneath of a carbide bar (stabilizer) 22 having a diamond point shape. [0037] FIG. 2A shows a wear blade runner 28 in carbide having a curved part 25 , in the front, a rear beveled part 27 and comprises in the interior, a thin sided carbide 30 acting as a knife blade penetrating snow, ice and rough abrasive surface 26 . The constant thinness is to give superior driving adherence, on hard, icy snowy surfaces. In FIG. 2A the wear blade runner 28 in carbide may preferably be rectangular, slightly inclined and sharpened ( FIG. 4 ). In FIG. 2B the profile of the thin carbide 30 appears in the slit. [0038] FIG. 3 shows for prior art the original runner 20 and the carbide bar 22 . This carbide bar has a point 51 . In operation after a certain while, the end of the point wears out until a point maximum level of use 42 . The depth 44 maintains the carbide bar in position. At that very moment there is no biting by the carbide because the carbide has enlarged. A maximum wear is reached at a shoulder 46 where the cutting efficiency is null on ice or hard surface, the wearing out continuing on the runner seating surface as far as half of the runner circle. Dotted lines show the relative thinness of a proposed side carbide ( FIG. 4 ). [0039] FIG. 4 shows a wear blade runner 28 made in a rectangular shape: short sides 29 , 29 ′ oriented top to bottom and large sides 31 disposed perpendicularly of the side of a ski. The runner 28 is of two parts, namely a support 40 of the above dimensions and a thin sided carbide 30 embedded in a sheath 32 . The sheath has a thin side 34 and two long sides 36 . Between the sheath and the flat carbide there is barely enough space to pass through a silver foil 37 to weld the carbide in place. After wear out on hard roads there is a new position 38 of the carbide; after wear out following frequent passages on abrasive paths and on icy ground filled with rocks a new position of the support 40 is found at depth 44 . The wear out position of the support 40 attaining the end of the carbide. The hardness of the support material is of 0 to 50 Rc but the hardness of the thin sided carbide 30 is of 60 to 80 Rc. A height of 1″ is possible for the large side 31 . The bolts 70 ( FIG. 2A ) serve to unify the wear blade runner 28 to the original ski. One sees a curved end 25 that is also sharp in the back 27 until the beginning of the curving part. The side carbide 30 can have typically a thickness of short side 34 of about 1/16″. It is possible to increase the thicknesses for more durability but with less efficiency. The thickness of the web 29 is twice to four times the thickness of the central carbide blade, to support well the carbide blade. [0040] In use the turning of the skis equipped with a wear runner causes the digging of a channel along the guided direction and a better adherence of 66% more than a carbide runner with diamond point when reaching the maximum level of use 42 ; ( FIG. 3 ) the utilization of the runner provided with the thin sided carbide 30 being the third of the original carbide bar 22 procures much more adherence and less friction when sliding. The overlapping of the point creates an excess 41 corresponding to 1/16″ of sliding depth in the ice so the overlapping of the original carbide bar corresponds to ¼″. As well, the wear blade runner itself corresponds to ¼″ to 3/16 large but the original runner is 7/16 to ½″ large and round. A round runner does not offer a cutting easiness but gives more resistance when sliding, especially for its largeness ( 7/16″) is almost the double of the wear blade runner 28 . All restriction to sliding by a large runner causes way less adherence, less cutting easiness, a loss of speed, an increase in gas consumption, what is not useful for the consumer. Therefore, it is preferable to add a blade bevel 45 at the end of the blade, combined with a runner bevel 43 at the end of the runner. [0041] FIG. 5 shows the underside of a snowmobile ski 120 in—dotted line—, fitted with a stabilizer 122 . The stabilizer 122 starts on the rear end, just before the curved part 124 , and stretches to the front end 126 of the ski 120 , just before a strong curve 128 . The stabilizer 122 is placed on a lowered center channel 130 located in the middle of two carrying sides 132 . The lowered center channel 130 receives a carbide bar 122 that protects the ski when sliding over asphalt. The carbide bar 122 also helps veering when moving on icy surface. The stabilizer 122 has a U-shaped section 136 with wings 138 , pointing downward, in order to penetrate snow. Section 136 is made of metal. A corrector 140 is placed on a web 142 of the U-.shape section 136 and comprises a bend 144 . A resilient section 141 bears against the front end of a steel stabilizer 122 when the front end 126 of the ski is bent. The corrector 140 may be made of Teflon™ or Tivor™ type material or of UHMW polyethylene plastic. Front and back bolts 146 , 147 fix the corrector 140 and the stabilizer 122 . The wings 138 are two (2) to three (3) mm thick, preferably 2 mm and are 19 mm high. The corrector 140 has an extension 150 at the front and stretches to the front end 126 of the ski. [0042] It is possible to use an L-shaped channel with the short part of the L replacing a wing of the U but it is preferable to have the carbide bar 134 located between the two wings 138 . The carbide bar 134 not only protects when crossing on asphalt roads but facilitates turning when on icy roads because it supports the ski on a single point. A typical height of wing 138 is 18 mm with variations from 6 to 50 mm. The width of the web 142 may be from 25 to 150 mm with typical value at 40 mm. The carbide bar 134 may be of different lengths in order to fit the skis being used by a snowmobile manufacturer. The wings may be covered by carbide plates 152 such as appears on one wing or by a spread of carbide or diamond powder 153 such as is shown on the second wing. [0043] FIG. 6 shows an aggressive snowmobile ski 220 comprising a ski support 231 , a blade 230 provided with an aperture 234 , and a wear runner 228 . One sees also the wear runner 228 exceeds the blade 230 and the blade point 238 . This way the runner is lower than the blade; the blade will rub to a hard surface, but the blade point 238 will stay upwards. It is obligatory that the ski of the present invention be provided with such a wear runner where the blade point 238 or a rear edge 232 of the aperture would be damaged by crossing for example a railroad track. The aperture is formed of the rear edge 232 , the front edge 240 , and can also be formed of a superior edge localized between the blade point 238 and a blade support leaning on a ski. The direction of the snowmobile 222 is also illustrated that is why the angle of the rear edge 232 is less inclined than the front edge, the front edge could be cut at 90° so be the rear edge could be at 90° to facilitate the passage of rocks or other hazards. In the present illustration, the aperture corresponds to the total width of the blade 242 , that is why there is no superior edge. Such opening width is preferable because it gives less resistance to the exiting of the snow in sudden turns. [0044] FIG. 7 shows the aggressive ski in action. The ski slides on the snow 224 , the front appearing at the left. When the wear runner 228 gets into contact with snow, the snow is compressed on all the height of the blade 230 including the rear edge 232 in slope and the pressure can provoke a slight lifting of ski. In the shown ski, the apertures 234 permit the evacuation of snow. The snow pressure under the ski is re-established and the ski will no longer have the tendency to lift. This compensation effect can be compared to the aquaplane effect under tires of motor vehicles. [0045] FIG. 8 shows an embodiment of the invention on a snowmobile ski provided with a steering stabilizer 246 (CA 2,300,359, of the same inventor), wherein a snowmobile ski 244 is shown in—dotted lines—. One sees an aperture 234 practiced in the blade 230 , and the aperture is situated opposite the wear runner 228 . [0046] FIG. 9 shows an embodiment of the invention to a concave snowmobile ski provided with a concave ski stabilizer 248 (CA 2,388,801, of the same inventor), wherein a concave ski 250 is shown in phantom lines. One sees an aperture 234 practiced in blades 230 , and the aperture is oppositely located to the runner. The rear edge is rounded instead of showing a 45″ slope. In the case of the concave ski, the evacuation of snow is made towards the inside of the ski; the pressure of snow is decreasing for the concavity yielding a greater volume. [0047] FIG. 10 shows an independent blade 230 , separated by the runner 228 and mounted on a support 231 which is the sliding part of a ski. [0048] FIG. 11 shows blades 230 and a central runner 228 all incorporated in one piece bolted on the ski. One sees the aperture oppositely to the central runner. [0049] FIG. 12 shows each side of the concavity 352 towards the left of a cut reversed U-section forming a web 360 and a blade 358 making a pair with a right reversed U forming a web 360 and a blade 356 . A pair of carbide runners 328 appears to the receptacle limits 354 and to a web 360 under a ski. The carbide runner is attached with bolts 370 and comprises a support 340 and a thin sided carbide 330 . The support comprises a large side 331 and a short flat side 329 , wherein there is a sheath 332 containing the thin sided carbide 330 . One sees the wear out position, either the carbide position 338 or the position of the support 340 . The support is built in softer steel such as 50 Rc and permits to disengage faster than the carbide at 80 Rc to allow the carbide to be always out, ready to cut. One sees between the position of the sheath 332 and the position of the large side 331 a silver foil 337 to weld the carbide to the support. The exceeding carbide 367 protects the blade 358 , 356 when it slides on a hard surface as asphalt, and keeps the cut helping the runner 328 to turn in digging in a rough or rugged surface until the wearing out of the carbide and then the support at its turn, is altered by abrasion. An active member 362 meant to draw a furrow in the snow by means of a marker 364 located at its bottom end. The carbide runner can endorse several shapes. It can be round, hexagonal, square or rectangular such as shown. The bolt 370 passes through the wing 323 . There is a hole in the web permitting the passage of the bolt. When the bolt is welded to the runner, it passes the web into the receptacle, through the wing to reach the ski. [0050] FIG. 13 shows a typical ski 371 possessing bearing sides. The wings 323 are typically 1″ thick, 45″ long and ¾″ large. The blade 356 is placed at an angle of about 80 to 90° and is overhang by the web along all the sliding distance of the ski, about 24″. The bolts serve to join the moveable runner to the concave ski 371 . A curved end 325 is also sharp; and correspondingly at the back until the curved part. [0051] It is possible to increase the thickness for more durability but with less efficiency. The web thickness is corresponding to the blade for it may come from the same curved part. The three pieces, the web 360 and the internal blades 356 , 358 come from tempered steel at 30 to 60 and preferably 50 Rc. The runner is bolted 370 to the web and to the ski and it is preferably of the self adjusting type. The concavity constitutes a dome space permitting the evacuation of the snow moved by the blades. [0052] FIG. 14 shows the bottom side of a snowmobile ski 420 having sides 422 and a thick central section 424 , provided with a curved part 425 at the front. A pair of external knives 426 appears at the limit of the central part 424 . These knives end at a beveled front 428 and a straight rear 430 . The central part 424 receives a central runner 432 protecting the ski when sliding on a hard surface. The central runner 432 helps also the turning on icy or snowy surfaces. [0053] FIG. 15 is split into cuts 15 . 1 , 15 . 2 and 15 . 3 . In the embodiment of FIG. 15 shows a central runner 432 taking different shapes. It can be round, square, hexagonal or rectangular. The ski possesses bearing sides 434 typically of ¼″ thick, 45″ long and 1¼″ large. The thickened section 424 includes two slope sides 436 of approximately 1″ long of each side to bind to a flat part 440 that supports a runner. This runner can be overhang by a carbide runner to form a hard foot 438 . The knife 426 is placed at an angle of 80° and comes into the sheath 441 receiving a blade 426 ′ inclined. The knife 426 possesses a low limit 447 . A thickened region 424 comprises also a side 442 at 90° with a bearing side. A height of ¾″, is possible between an edge 444 and a bearing side 434 . A top 446 is relatively flat but for the external reinforcements 448 disposed above and toward the exterior. A central reinforcement 450 is disposed centrally and oppositely the central runner 432 . Pockets 452 disposed near the central reinforcement 450 help to make the structure lighter. An aluminum U- channel 454 is disposed on the top 446 and join the reinforcements 448 , 448 ′, 450 to strengthen the ski. The U channel 454 has plies 456 joining the external reinforcements 448 by means of bolts and rivets 458 . A knife attach 460 takes the shape of a bolt, penetrates the U-channel 454 and the thickened region to reach the knife blade by a cavity 462 wherein passes a welded bolt to a place on the knife. This is repeated in various places to give the knife the strength to maintain in place. [0054] FIG. 16 shows an original ski 464 comprising a pair of wing parts 466 and a low part 468 . A low corner 470 defines a limit between a low flat part 468 and a curved part 469 forming a bearing part joining the wing part 466 . A moveable runner 472 from fore to aft ends is disposed on the sliding part of the ski and particularly under the low part 468 . Bent blades 476 , 476 ′ are disposed towards the exterior and a central wear runner 478 is welded to a web 474 . The central wear runner can be slightly sharpened towards the bottom or take a rectangular shape. Between the central wear runner 478 and a bent blade 476 , there is a sharp angle 475 forming a sharp interior of a M. Nuts 477 serve to unify the moveable runner 472 to the original ski 464 . A succession of deformities creating central plates 494 ( FIG. 17 ) in the central line of the moveable runner 472 oppositely to the bolts to position to a bolt head 502 to ( FIG. 18 ). One sees a curved end 480 which is also sharp and similarly to the back until the beginning of the curved part. [0055] FIG. 17 shows an original ski which was added the original runner 472 . In looking at the moveable runner one sees an aperture 482 about 2¾″ and a sharpening slope 484 of about 80° to give a reversed W shape look. The slope can also be of 90° in case of a simple M. The knife can also have thickness 488 of 1/16″. It is possible to increase the thicknesses for more durability but less efficiency. The web thickness 492 is of same caliber of the knife because it may come from the same curved metal part. The web and the external knives, come from tempered steel at 30 to 60, preferably 50 Rc. The central runner 478 comprises a hard foot 438 such as FIG. 4 runner 28 and carbide 30 , the runner being welded through the web and to the central plate 494 to prevent wear out of the weld. Central plates 494 are large enough to receive the flat part of the bottom of the ski 468 which can be 1¼″ large where it has bolts. The web 474 is ended by a turned up point 496 defining a V space to let pass the snow moved by the central runner. At a limit, the web could be slightly concave or even flat, but if it would become convex it would mean a loss of efficiency for the portion of the useable surface to place the snow during passages of the central wear runner 478 would not be large enough. The area of the runner may be ½″ long by 5/16″ wide. At the end of the central runner it may appear a sharpening 490 to give more penetration. The central runner acting as a blade can be equal or lower than the knives because in use it will wear out until the three blades 488 , 488 ′, 478 are equal in height for they are equally used for a better cutting efficiency. A carbide 438 helps protecting from wearing out; the knives 426 , 426 ′ which support the central runner 478 . [0056] FIG. 18 shows a moveable runner 472 seen from the bottom turned upside down: one sees a number of slits 500 to receive bolts and one perceives also a flat piece 502 and a hidden bolt head 503 . At the front the bolt has an observable bolt head 504 . A hole 505 is drilled to fix, by means of a bolt, the end of the moveable runner. SUMMARY [0057] A self sharpening runner meant to be fixed to a slide ski face, the self sharpening runner comprising: a rectangular wear blade runner 28 having a short side 29 oriented upward on the slide ski face, two large sides 31 disposed perpendicularly of the slide ski face and a low short side 29 ′ oriented downward against the ground, the low short side comprising a sheath 32 , the wear blade runner having a first hardness; the sheath having two parallel sides placed from the slide face until a depth 44 , the sheath receiving a blade 30 having an excess 41 comparing to the slide ski face and having a second hardness higher than the first hardness so when the self sharpening runner travels on a hard surface as asphalt or ice, only the blade is in contact and exposed to wearing out, but when the self sharpening runner travels on a penetrable surface as snow blend with salt, sand, or gravel, the blade penetrate the surface and the blade support is also exposed to abrasion; successive passage of the blade 30 and the sliding ski face on a hard and abrasive surface as asphalt roads causing partial abrasion only on the blade and the passage of the blade and the sliding ski face on abrasive matter a little less harder causing penetration of the blade, its wearing out, and meanwhile the wearing out of the low short side of the blade support of the first hardness; for the first hardness of the blade support is inferior to the blade hardness, the excess 41 which is responsible for an efficient cut in the hard matter is maintained until complete wearing out of the blade when a ratio of the first hardness compared to the second hardness is chosen for successive passages on hard abrasive surface and penetrable surface, completing a self sharpening and a constant and even cut until complete wearing out. [0061] The wear blade runner is of a thinness permitting a penetration of its rectangular shape in trail hard snow and the blade is about 2 mm smaller than the low short side and possesses a thinness making a sharp knife in an ice trail meant to create a deep furrow and to procure an efficient direction while driving until complete wearing of the runner. [0062] The self sharpening runner having a hardness ratio of the blade comparing to the support between 1.3 and 2.4. When mild steel is used in the support the carbide blade must be at least 50 Rc. [0063] The thickness of the blade being a third of the width of the wear blade runner. [0064] The blade is about 2 mm large, when the wear blade runner is about 6 mm. [0065] The self sharpening runner used in combination with a stabilizer 122 having a front 126 and a long body installed longitudinally under the slide ski surface, the stabilizer comprising: a pair of cutting elements comprising two thin blades disposed externally of the snowmobile ski runner, all three elements being positioned below the ski, with the centre element comprising means for bearing over hard passages for preventing wear of the thin blades, stabilizer comprising means at the front 126 to flatten snow between the two thin blades, the stabilizer comprising a slide surface for longitudinal sliding between the two blades; the combination of the three cutting elements in the flattened snow forcing the snow along the longitudinal sliding, thereby diminishing side swaying. [0070] The self sharpening runner used in combination with: a snowmobile ski 220 comprising at least a blade 230 and at least a wear runner 228 , the blade comprising at least an aperture 234 , the aperture situated oppositely or slightly towards the front or towards the back of the runner when seen from the side. [0072] A method to improve the adherence of snowmobile skis having at least a runner and at least a blade during fast turns comporting at least the following step: creating at least an aperture oppositely of at least a runner in at least an existing blade. [0074] A snowmobile ski 220 having at least a blade 230 having a width 242 having a blade point 238 , the ski comprising at least a wear runner 228 , the blade comprising at least an aperture 234 , the aperture located oppositely the runner or slightly towards the front or towards the back if seen from the side. [0075] The snowmobile wear runner used in combination with two blades 230 carrying apertures 234 . [0076] A method to improve the adherence of snowmobile skis during fast turns the method comporting the following steps: installing at least a runner 228 and at least a blade 230 , the blade comprising a largeness 242 and a blade point 238 , the runner comprising a carbide point 239 disposed lower than the blade point, practice an aperture 234 in the blade oppositely the runner. [0079] In a concave ski 371 comprising a sliding length and a width comprising a concavity 352 and two bearing wings 323 ), one on each side of the concavity and spread along the sliding length, the bearing wings comprising each a runner 328 , a stabilizer comprising: at least a blade 358 disposed vertically and comprising means to adapt inside the concavity, the blade meant to create a path which added to the runners 328 , producing at least three parallel furrows. [0081] The snowmobile ski runner used in combination with a concave ski 371 comprising a stabilizer comprising: at least a blade 356 , 358 disposed vertically and comprising means to adapt inside the concavity, the blade meant to create a path which added to the runners 328 , produces at least three parallel furrows. [0083] The snowmobile ski runner used in combination with a snowmobile ski 420 having a sliding side comprising a thick central section 424 and a bearing wing 434 disposed longitudinally on each side of the thick central section, the central section comprising: a central runner 432 under which is fixed a hard foot 438 , a smooth face oriented from the central runner towards the top at an angle from 0 to 60° and prolonging on both sides of the central runner on a short distance in direction of the wings and ending on each side by an edge 444 delimitating an exterior side, two longitudinal knife blades 426 , 426 ′ having a low cutting limit 447 and localized in the smooth face near the edge, means of retention 460 to give rigidity to each the knife blade to allow the knives to make paths in the snow, the hard foot being sensibly at the same level as the low cutting limits, permitting to create three close furrows of equal depth in the snow. [0088] The self sharpening central runner localized half-way between the blades and held by slope sides 436 forming a sharp angle with the blade 426 , a section of the ski defining a structure in M for the blades 426 , the slopes 436 and the hard foot 438 , the combination of the blades and the hard foot defining three blades 426 , 438 , 426 ′ making three furrows at a time and the slopy part 436 serving in reserve for cutting snow by the central runner 432 , 438 , the blades being oriented to 80±5° from the horizontal when the three blades 426 , 438 , 426 ′ are moved on a hard surface, the blades in slopes being sharpened on the outside. [0089] A moveable runner 472 having a M or a reversed W shape meant to be added to an existing ski to make it self stabilized, the existing ski comprising in section a low part 468 , two wing parts 466 situated one at the left and the other at the right of the low part, two angled parts 469 situated between the low part and either one or the other wing part the moveable runner 472 comprising: a concave web 474 comprising a central plate 494 and two turned up points 496 ; means to unify the central plate 494 to the low part 468 of the ski; the moveable runner 472 comprising also at the end of the points 496 two knife walls 488 directed towards a low cutting limit 447 ; a central runner 478 disposed under the central plate 494 and between the knife walls 488 of sensibly equal depth to the low cutting limit 447 , the central runner being sharpened. [0094] A self sharpening runner used in combination with a snowmobile ski comprising a principal body having a superior part and an inferior part; a central swelling extended longitudinally at the level of the inferior part and covering less than half less of the inferior part and being ended by a pair of edges; first and second knife blades localized in the central swelling, near the edge, the first and the second blades having cutting sides and the swelling having a bottom possessing centrally a carbide runner, so when the ski gets into contact with a snowy surface, the bottom, the carbide runner and the first and second knife blade being aligned to closely define an M. [0097] The self sharpening runner is sharpened when the snowmobile crosses a road. The road has a gravel side and a hard asphalt center. When passing over gravel both the blade and the support wear mostly the support. On asphalt only the blade wears, the amount of the excess 41 and protects the support as far as the depth 44 . [0098] It is well accepted that the embodiment of the present invention which was described above, in reference to the matched drawings, was given indicatively and certainly not limitative, and that modifications and adaptations could be brought without moving away from the object of the present invention. Other embodiments are possible and limited only by the scope of the appended claims. LEGEND 20-Original runner 22-Carbide bar 25-Curved part 26-Abrasive surface 27-Beveled part 27-Back 28-Wear blade runner 29-Short side 29′-Short side 29-Web 30-Thin sided carbide (Blade) 31-Large side 32-Sheath 34-Thin side 36-Long side 37-Silver foil 38-New position 40-Support 41-Excess 42-Maximum level of wear 43-Runner bevel 44-Depth 45-Blade bevel 46-Shoulder 51-Point 70-Bolts 120-Ski 122-Stabilizer 124-Curved part 126-Front end 130-Lower center channel 132-Carrying sides 134-Carbide bar 136-U shaped section 138-Wings 140-Corrector 141-Resilient section 142-Web 144-Bend 146-Front bolt 147-Back bolt 150-Extension 152-Carbide plates 153-Diamond powder 220-Agessive ski 222-Snowmobile 224-Snow 228-Wear runner 230-Blade 231-Ski support 232-Rear edge 234-Aperture 238-Blade point 240-Front edge 242-Largeness of blade 244-Ski 246-Steering stabilizer 248-Concave ski stabilizer 250-Concave ski 323-Bearing wings 325-Curved end 328-Runner 329-Short flat side 330-Thin sided carbide 331-Large side 332-Sheath 337-Silver foil 338-Carbide position 340-Support 352-Concavity 354-Receptacle limits 356-Blade 358-Blade 360-Web 362-Active member 364-Marker 367-Exceeding carbide 370-Bolts 371-Concave ski 420-Ski 422-Sides 424-Thick central section 425-Curved part 426-External knife 426-Blade 428-Beveled front 430-Straight rear 432-Central runner 432-Rear runner 434-Bearing wings 436-Two slope sides 438-Hard foot 440-Flat part 441-Sheath 442-Side 444-Edge 446-Top 447-Low cutting limit 448-External reinforcements 450-Central reinforcements 452-Pockets 454-Aluminum U-channel 456-Plies 458-Bolt rivets 460-Knife attach 462-Cavity 464-Original ski 466-Wing parts 468-Low parts 469-Angled part 470-Low corner 472-Moveable runner 474-Web 475-Sharp angle 476-Bent blades 476′-Bent blades 477-Nuts 478-Central wear runner 480-Curved end 482-Aperture 484-Sharpening slope 488-Knife walls 490-Sharpening 492-Web thickness 493-Weld 494-Central plates 496-Turned up point 500-Slit 502-Flat piece 503-Hidden bolt head 504-Observable bolt head 505-Hole	Improvements in snowmobile stabilizers are now available. The stabilizer comprises three parallel wear blades each of which is made to remain sharpened over a long period of time. The side blades may contain holes to divert the snow and to add roughness when engaging into a ski path, while a rectangular central part provides a blade support of a given hardness and holding a central blade of a much higher hardness, thereby permitting passage over rugged hard terrain while protecting the blade support against rapid wear. In soft abrasive gravel, the blade support wears partially thereby leaving a protruding central part, the protruding difference being self adjusting. In the case of the concave ski each side comprises a rectangular edge wear part coupled with a side blade for a total of four wear blades.	1
[0001] The present patent application claims the priority benefit of French patent application FR14/63372 which is herein incorporated by reference. BACKGROUND [0002] The present invention generally relates to methods of manufacturing electronic devices comprising microwires or nanowires made of a semiconductor material. DISCUSSION OF THE RELATED ART [0003] Microwires or nanowires comprising a semiconductor material particularly enable to manufacture optoelectronic devices. Term “optoelectronic devices” is used to designate devices capable of converting an electric signal into an electromagnetic radiation or the other way, and especially devices dedicated to detecting, measuring, or emitting an electromagnetic radiation or devices dedicated to photovoltaic applications. [0004] For certain structures where the nanowires or microwires are formed on a support, it is necessary to cover with an insulating layer the lower portion of each nanowire or microwire, as well as the support between the nanowires or microwires, while the upper portion of each nanowire or microwire is not covered with this insulating layer. It may however be difficult to achieve a uniform insulation of the feet of an assembly of nanowires or microwires, in particular to insulate the lower portion of each nanowire or microwire up to a height which is substantially the same for all microwires and nanowires. SUMMARY [0005] Thus, an object of an embodiment is to at least partly overcome the disadvantages of previously-described optoelectronic devices comprising microwires or nanowires. [0006] Another object of an embodiment is for the heights of insulation of the lower portions of nanowires or microwires of an assembly of nanowires or microwires to be substantially equal. [0007] Another object of an embodiment is to be able to form the optoelectronic device at an industrial scale and at a low cost. [0008] Thus, an embodiment provides a method of manufacturing an electronic device comprising a substrate and microwires or nanowires resting on the substrate, the method comprising the successive steps of: [0009] a) covering the microwires or nanowires with an insulating layer; [0010] b) covering the insulating layer with an opaque layer; [0011] c) depositing a first resist layer extending on the substrate between the wires; [0012] d) etching the first resist layer across a first thickness by photolithography; [0013] e) etching the first resist layer remaining after step d) across a second thickness by plasma etching; [0014] f) etching the portion of the opaque layer which is not covered with the first resist layer remaining after step e); [0015] g) etching the portion of the insulating layer which is not covered with the opaque layer; [0016] h) removing the first resist layer remaining after step e); and [0017] i) removing the opaque layer. [0018] According to an embodiment, the height of the microwires or nanowires is in the range from 250 nm to 50 μm. [0019] According to an embodiment, the maximum thickness of the first resist layer at step c) is greater than the height of the microwires or nanowires. [0020] According to an embodiment, the thickness of the insulating layer is in the range from 5 nm to 1 μm. [0021] According to an embodiment, the plasma etching is an oxygen plasma etching. [0022] According to an embodiment, the opaque layer is made of a metal or of a metal alloy. [0023] According to an embodiment, the thickness of the opaque layer is in the range from 5 nm to 1 μm. [0024] According to an embodiment, the method further comprises, after step i), the successive steps of: [0025] j) forming a shell on the portion of each microwire or nanowire which is not covered with the insulating layer, the shell comprising an active region capable of capturing or of emitting most of the radiation supplied or captured by the electronic device; [0026] k) forming an electrode layer on the shells and on the insulating layer; [0027] l) covering the electrode layer with a conductive layer; [0028] m) depositing a second resist layer extending on the conductive layer between the wires; [0029] n) delimiting in the second resist layer, by photolithography, a resist block extending between the microwires or nanowires; [0030] o) etching the resist block across a third thickness by plasma etching; [0031] p) etching the portion of the second reflective conductive layer which is not covered with the resist block remaining after step o); and [0032] q) removing the second resist layer remaining after step o). [0033] According to an embodiment, step n) comprises the steps of: [0034] r) partially illuminating the second resist layer across a fourth thickness; [0035] s) illuminating portions of the second resist layer across its entire thickness by using a masking screen; and [0036] t) etching the portions of the second resist layer illuminated at steps r) and s). [0037] According to an embodiment, the conductive layer is reflective. BRIEF DESCRIPTION OF THE DRAWINGS [0038] The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of dedicated embodiments in connection with the accompanying drawings, among which: [0039] FIG. 1 is a partial simplified cross-section view of an embodiment of an optoelectronic device comprising microwires or nanowires; and [0040] FIGS. 2A to 2P are partial simplified cross-section views of the structures obtained at successive steps of an embodiment according to the invention of a method of manufacturing the optoelectronic device of FIG. 1 . DETAILED DESCRIPTION [0041] For clarity, the same elements have been designated with the same reference numerals in the various drawings and, further, as usual in the representation of electronic circuits, the various drawings are not to scale. Further, only those elements which are useful to the understanding of the present description have been shown and will be described. In particular, the optoelectronic device biasing and control means are well known and will not be described. In the following description, unless otherwise indicated, terms “substantially”, “approximately”, and “in the order of” mean “to within 10%”, preferably to within 5%. [0042] The present application particularly relates to electronic devices having a three-dimensional structure comprising three-dimensional elements, for example, microwires, nanowires, conical elements, or frustoconical elements. In particular, a conical or frustoconical element may be a circular conical or frustoconical element or a pyramidal conical or frustoconical element. In the following description, embodiments are particularly described for electronic devices having a three-dimensional structure comprising microwires or nanowires. However, such embodiments may be implemented for three-dimensional elements other than microwires or nanowires, for example, conical or frustoconical three-dimensional elements. [0043] Term “microwire”, “nanowire”, “conical element”, or “frustoconical element” designates a three-dimensional structure having a shape elongated along a preferred direction, having at least two dimensions, called minor dimensions, in the range from 5 nm to 2.5 μm, preferably from 50 nm to 2.5 μm, the third dimension, called major dimension, being greater than or equal to 1 time, preferably greater than or equal to 5 times, and more preferably still greater than or equal to 10 times, the largest minor dimension. In certain embodiments, the minor dimensions may be smaller than or equal to approximately 1 μm, preferably in the range from 100 nm to 1 μm, more preferably from 100 nm to 800 nm. In certain embodiments, the height of each microwire or nanowire may be greater than or equal to 500 nm, preferably in the range from 1 μm to 50 μm. [0044] In the following description, term “wire” is used to mean “microwire” or “nanowire”. Preferably, the median line of the wire which runs through the centers of gravity of the cross-sections, in planes perpendicular to the preferred direction of the wire, is substantially rectilinear and is called “axis” of the wire hereafter. [0045] In the following description, embodiments will be described in the case of an optoelectronic device comprising light-emitting diodes. It should however be clear that these embodiments may concern other applications, particularly devices dedicated to the detection or to the measurement of electromagnetic radiation or devices dedicated to photovoltaic applications. [0046] FIG. 1 is a partial simplified cross-section view of an optoelectronic device 10 formed from wires such as previously described and capable of emitting an electromagnetic radiation. [0047] Device 10 comprises, from bottom to top in FIG. 1 : [0048] a first biasing electrode 12 ; [0049] a substrate 14 , for example, semiconductor, comprising parallel surfaces 16 and 18 , where surface 16 is in contact with electrode 12 and surface 18 may be treated to favor the growth of wires in organized fashion, and the treatment may comprise forming a layer, not shown, at the surface of substrate 14 ; [0050] wires 20 of axis Δ (three wires being shown) of height H 1 , each wire comprising a lower portion 22 of height H 2 , in contact with surface 18 , and an upper portion 24 of height H 3 ; [0051] an insulating layer 26 covering the periphery of a portion of each lower portion 22 and covering substrate 14 between wires 20 ; [0052] a shell 28 covering each upper portion 24 ; [0053] a second electrode layer 30 covering shells 28 and insulating layer 26 ; and [0054] a conductive portion 32 covering second electrode layer 30 between wires 20 , and possibly extending over a portion of the lower portion 22 of each wire 20 , without extending over the upper portion 24 of each wire 20 . [0055] Each wire 20 is at least partly made up of at least a semiconductor material. According to an embodiment, the semiconductor material is selected from the group comprising III-V compounds, II-VI compounds, or group-IV semiconductors or compounds. [0056] The assembly formed by each wire 20 and the associated shell 28 forms a light-emitting diode. Shell 28 particularly comprises an active area, which is the layer from which most of the electromagnetic radiation delivered by light-emitting diode is emitted. According to an example, the active area may comprise confinement means, such as multiple quantum wells. In the present embodiment, at least certain light-emitting diodes have common electrodes and when a voltage is applied between electrodes 12 and 30 , a light radiation is emitted by the active areas of these light-emitting diodes. [0057] The light-emitting diodes of optoelectronic device 10 may be distributed in an assembly, two assemblies, or more than two assemblies of light-emitting diodes. Each assembly may comprise from a few light-emitting diodes to several millions of light-emitting diodes. [0058] In the present embodiment, insulating layer 26 enables to delimit shell 28 for each wire 20 and provides an electric insulation between electrode layer 30 and substrate 14 . [0059] In the present embodiment, conductive portion 32 advantageously enables to decrease the resistance of electrode layer 30 . Preferably, conductive portion 32 is reflective and advantageously enables to increase the proportion of the radiation emitted by the light-emitting diodes which escapes from optoelectronic device 10 . [0060] FIGS. 2A to 2P are partial simplified cross-section views of the structures obtained at successive steps of another embodiment of a method of manufacturing optoelectronic device 10 shown in FIG. 1 . [0061] FIG. 2A shows the structure obtained after having grown wires 20 on substrate 14 . [0062] Substrate 14 may correspond to a monoblock structure or correspond to a layer covering a support made of another material. Substrate 14 is preferably a semiconductor substrate, for example, a substrate made of silicon, of germanium, of silicon carbide, of a III-V compound, such as GaN or GaAs, or a ZnO substrate, or a conductive substrate, for example, a substrate made of a metal or a metal alloy, particularly copper, titanium, molybdenum, and steel. Preferably, substrate 14 is a single-crystal silicon substrate. Preferably, it is a semiconductor substrate compatible with manufacturing methods implemented in microelectronics. Substrate 14 may correspond to a multilayer structure of silicon-on-insulator type, also called SOI. In this case, electrode 12 may be formed on the side of surface 18 of substrate 14 . Substrate 14 may be heavily doped, lightly-doped, or non-doped. [0063] A previous treatment of substrate 14 to favor the growth of wires 20 at preferred locations may be provided. The treatment applied to the substrate to favor the wire growth may correspond to one of the treatments described in documents U.S. Pat. No. 7,829,443, FR 2995729, or FR 2997558. [0064] Wires 20 may be at least partly made up of semiconductor materials mainly comprising a III-V compound, for example, a III-N compound. Examples of group-III elements comprise gallium (Ga), indium (In), or aluminum (Al). Examples of III-N compounds are GaN, AlN, InN, InGaN, AlGaN, or AlInGaN. Other group-V elements may also be used, for example, phosphorus or arsenic. Generally, the elements in the III-V compound may be combined with different molar fractions. [0065] Wires 20 may be at least partly formed based on semiconductor materials mainly comprising a II-VI compound. Examples of group-II elements comprise group-IIA elements, particularly beryllium (Be) and magnesium (Mg), and group-IIB elements, particularly zinc (Zn), cadmium (Cd), and mercury (Hg). Examples of group-VI elements comprise group-VIA elements, particularly oxygen (O) and tellurium (Te). Examples of II-VI compounds are ZnO, ZnMgO, CdZnO, CdZnMgO, CdHgTe, CdTe, or HgTe. Generally, the elements in the II-VI compound may be combined with different molar fractions. [0066] Wires 20 may be at least partly made up of semiconductor materials mainly comprising at least one group-IV compound. Examples of group-IV semiconductor materials are silicon (Si), carbon (C), germanium (Ge), silicon carbide alloys (SiC), silicon-germanium alloys (SiGe), or germanium carbide alloys (GeC). [0067] Height H 1 of each wire 20 may be in the range from 250 nm to 50 μm, preferably from 1 μm to 20 μm. Each wire 20 may have a semiconductor structure elongated along an axis substantially perpendicular to surface 18 . Each wire 20 may have a generally cylindrical shape. The axes of two adjacent wires 20 may be distant by from 0.5 μm to 20 μm and preferably from 3 μm to 20 μm. As an example, wires 20 may be regularly distributed, particularly in a hexagonal or square network. [0068] The cross-section of wires 20 may have different shapes, such as, for example, an oval, circular, or polygonal shape, particularly triangular, rectangular, square, or hexagonal. It should thus be understood that term “diameter” or “average diameter” in a cross-section of a wire or of a layer deposited on this wire designates a quantity associated with the surface of the targeted structure in this cross-section, for example corresponding to the diameter of the disk having the same surface area as the cross-section of the wire. The average diameter of each wire 20 may be in the range from 50 nm to 10 μm, preferably from 200 nm to 10 μm. [0069] The wire growth method may be a method such as chemical vapor deposition (CVD) or metal-organic chemical vapor deposition (MOCVD), also known as metal-organic vapor phase epitaxy (MOVPE). However, methods such as molecular-beam epitaxy (MBE), gas-source MBE (GSMBE), metal-organic MBE (MOMBE), plasma-assisted MBE (PAMBE), atomic layer epitaxy (ALE), or hydride vapor phase epitaxy (HVPE) may be used. Further, electrochemical processes may also be used, for example, chemical bath deposition (CBD), hydrothermal processes, liquid aerosol pyrolysis, or electrodeposition. [0070] As an example, the method may comprise injecting into a reactor a precursor of a group-III element and a precursor of a group-V element. Examples of precursors of group-III elements are trimethylgallium (TMGa), triethylgallium (TEGa), trimethylindium (TMIn), or trimethylaluminum (TMAl). Examples of precursors of group-V elements are ammonia (NH 3 ), tertiarybutylphosphine (TBP), arsine (AsH 3 ), or dimethylhydrazine (UDMH). [0071] FIG. 2B shows the structure obtained after having deposited insulating layer 26 over all the wires 20 and over surface 18 between wires. Insulating layer 26 may be made of a dielectric material, for example, of silicon oxide (SiO 2 ), of silicon nitride (Si x N y , where x is approximately equal to 3 and y is approximately equal to 4, for example, Si 3 N 4 ), of silicon oxynitride (particularly of general formula SiO x N y , for example, Si 2 ON 2 ), of hafnium oxide (HfO 2 ), of aluminum oxide (Al 2 O 3 ), or of diamond. As an example, the thickness of insulating layer 26 is in the range from 5 nm to 1 μm, preferably from 10 nm to 500 nm, for example, equal to approximately 300 nm. Insulating layer 26 may be deposited as an example by plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD), sub-atmospheric chemical vapor deposition (SACVD), CVD, physical vapor deposition (PVD), or atomic layer deposition (ALD). [0072] FIG. 2C shows the structure obtained after having deposited an opaque layer 40 on insulating layer 26 . Opaque layer 40 may be made of a metal or of a metal alloy, for example, aluminum (Al), titanium (Ti), copper (Cu), an alloy of aluminum and of silicon, or tungsten (W). The thickness of opaque layer 40 may be in the range from 50 nm to 1 μm, preferably from 100 nm to 200 nm, for example, equal to approximately 150 nm. Opaque layer 40 is, as an example, deposited by PVD, CVD, or ALD. [0073] FIG. 2D shows the structure obtained after having deposited a layer 42 of a resist over the entire structure. Resist layer 42 is particularly present between wires 20 . The maximum thickness of resist layer 42 is greater than height H 1 of wires 20 . The maximum thickness of resist layer 42 is in the range from 250 nm to 50 μm. [0074] FIG. 2E shows the structure obtained after a first step of partially etching resist layer 42 where only an upper portion of resist layer 42 is removed. The thickness removed from resist layer 42 after the first etch step may be of a few micrometers. The first etch step is preferably a photolithography step comprising a step of illuminating resist layer 42 , for example, by exposing resist layer 42 to an ultraviolet radiation, and a step of developing the resist layer where a portion of the resist layer is removed, for example, by liquid etching by placing the resist in contact with a developer. The resist may be a positive resist, that is, the portion of the resist exposed to an adapted radiation becomes soluble with the developer and the resist portion which is not exposed remains non-soluble. A partial illumination and development of the resin, particularly by adjustment of the illumination energy and/or of the illumination time, may then be implemented. The energy of the radiation may for example be in the range from 20 to 100 mW/cm 2 . The illumination time is for example in the range from a few seconds to some hundred seconds. The resist may be a negative resist, that is, the portion of the resist exposed to an adapted radiation becomes non-soluble with the developer and the resist portion which is not exposed remains soluble. In this case, a partial development of the resist by adjustment of the development time may be implemented with no exposure of the resist or with an exposure subsequent to the development. [0075] According to an embodiment, wires 20 may be at least partly transparent. The presence of opaque layer 40 then enables to decrease, or even to suppress, the guiding of the illumination radiation by wires 20 , which may cause an unwanted overexposure of regions of resist layer 42 around wires 20 . [0076] FIG. 2F shows the structure obtained after a second step of etching resist layer 42 where resist layer 42 is partially etched again, only an upper portion of the resist layer 42 obtained at the end of the previous step being removed. The thickness removed from resist layer 42 after the second etch step may be in the range from a few hundreds of nanometers to a few micrometers. The second etch step preferably is an etch step using an oxygen-based plasma. [0077] According to an embodiment, any conventional etch source such as RIE (reactive ion etching) and high-density plasma sources, particularly any etch source of the type used to etch organic materials, may be used for the plasma etch method according to the invention. The excitation power may be in the range from 10 W to 1 kW. The substrate may be maintained at the room temperature, for example, at 20° C. [0078] The use of a plasma etching advantageously enables to accurately and reproducibly reach the height desired for resist layer 42 . Further, the use of a plasma enables to clean the exposed surfaces for the subsequent steps, particularly by removing unwanted organic residues. This further enables to avoid parasitic effects which occur during the exposure of a photolithography due to the shape of the wires and of the layers present, particularly causing a narrowing of the resist bands (notching). [0079] FIG. 2G shows the structure obtained after a step of etching the portion of opaque layer 40 which is not covered with resist layer 42 and a step of etching the portion of insulating layer 26 which is then no longer covered with opaque layer 40 . The etching of opaque layer 40 may be a wet or dry etching (plasma etching). The etching of insulating layer 26 may be a wet or dry etching (plasma etching). Preferably, the etchings are selective over the resist. [0080] FIG. 2H shows the structure obtained after a step of removing the remaining resist layer. The removal of the remaining resist layer may be performed by dipping the structure shown in FIG. 2G into a bath containing a solvent capable of dissolving resist layer 42 . [0081] FIG. 2I shows the structure obtained after a step of etching opaque layer 40 . The etching may be a wet or dry etching (plasma etching) selective over wires 20 and over layer 26 . [0082] Steps 2 J to 2 P which will be described are capable of forming the structure shown in FIG. 1 . Generally, the subsequent steps of the method will depend on the envisaged application. [0083] FIG. 2J shows the structure obtained after the steps of: [0084] forming shell 28 for each wire 20 , for example, by MOCVD; [0085] forming first electrode 30 , for example, by MOCVD, ALD, PVD, CVD, or PECVD; and [0086] forming a conductive layer 44 covering first electrode 30 , for example, by PVD, ALD, CVD, or vacuum evaporation. [0087] Electrode 30 is capable of biasing the active area of the shell 28 covering each wire 20 and of letting through the electromagnetic radiation emitted by the light-emitting diodes. The material forming electrode 30 may be a transparent and conductive material such as indium tin oxide (ITO), zinc oxide, doped or not with aluminum or gallium or boron, or graphene. As an example, electrode layer 30 has a thickness in the range from 20 nm to 500 nm, preferably from 100 nm to 200 nm. [0088] Conductive layer 44 may correspond to a metal layer, for example, made of aluminum, of silver, of copper, of gold, or of ruthenium or of an alloy of at least two of these compounds. As an example, conductive layer 44 has a thickness in the range from 100 to 2,000 nm. Preferably, layer 44 is reflective. [0089] FIG. 2K shows the structure obtained after having deposited a layer 46 of a resist over the entire structure. Resist layer 46 is particularly present between wires 20 . The maximum thickness of resist layer 46 is preferably greater than the height of wires 20 covered with shells 28 , with electrode layer 30 , and with conductive layer 44 . The maximum thickness of resist layer 46 is in the range from 250 nm to 50 μm. Resist layer 46 may have the same composition as resist layer 42 . [0090] FIG. 2L shows the structure obtained after a first partial illumination of resist layer 46 where only an upper portion of resist layer 46 is exposed and a second partial illumination of resist layer 46 , particularly by using a masking screen. The two illumination steps result in illuminating the entire resist layer 46 except for a resist block 48 which extends over layer 44 between wires 20 only up to a portion of the height of wires 20 . In FIG. 2L , a hatched area 47 1 is used to show the upper portion of resist layer 46 exposed during the first illumination step and a hatched area 47 2 is used to show the additional portion of resist layer 46 exposed during the second illumination step. [0091] FIG. 2M shows the structure obtained after an etch step which results in obtaining resist block 48 . The etching is preferably a step of developing resist layer 46 of a photolithography method. [0092] FIG. 2N shows the structure obtained after a second step of etching resist block 48 where only an upper portion of resist block 48 is removed. This step may be carried out by a plasma etching as previously described in relation with FIG. 2F for the second step of etching resist layer 42 . [0093] FIG. 2O shows the structure obtained after a step of etching the portion of conductive layer 44 which is not covered with resist block 48 . Conductive portion 32 is thus obtained. The etching of conductive layer 44 may be a wet or dry etching (plasma etching). Preferably, this etching is selective over the resist and over layer 30 . [0094] FIG. 2P shows the structure obtained after a step of removing resist block 48 .	A process for fabricating an electronic device including a substrate and microwires or nanowires resting on the substrate, the process including successive steps of covering the wires with an insulating layer, covering the insulating layer with an opaque layer, depositing a first photoresist layer over the substrate between the wires, etching the first photoresist layer over a first thickness by photolithography, etching the first photoresist layer remaining after the preceding step over a second thickness by plasma etching, etching the portion of the opaque layer not covered by the first photoresist layer remaining after the preceding step, etching the portion of the insulating layer not covered by the opaque layer, removing the first photoresist layer remaining after the preceding step, and removing the opaque layer.	7
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an automatic original handling device used in a copying apparatus, and more particularly to a device for automatically conveying and stopping an original to be copied to and at the original carriage portion of a copying apparatus and for automatically returning the original from the apparatus after the optical scanning necessary for the image formation corresponding to the original has been effected, and for automatically conveying another original in succession. 2. Description of the Prior Art Heretofore, placement of an original on the original carriage portion of a copying apparatus has often been manually effected by the operator of the copying apparatus and this has required much labor and much time and moveover, has suffered from not a little deviation of the original from its proper position, thus preventing proper copying from being performed. As a solution to these problems, there is known a conveyor device for automatically conveying an original to the original carriage portion. For example, U.S. Pat. No. 3,844,552 discloses a construction in which original conveyor means comprising a belt passed over two rollers is provided on the original carriage portion so that originals are conveyed by the friction between the belt and the surface of the original carriage and originals are registered and stopped by an original stop member provided at an end of the original carriage surface. However, in such device, since flexible originals conveyed by the friction between the belt and the original carriage surface is mechanically stopped by the stop member, the originals nipped between the belt and the original carriage surface tend to be bent or wrinkled or otherwise damaged. As another example, U.S. Pat. No. 3,829,083 discloses a device in which originals placed on an original support bed are fed therefrom by a separating roller and the trailing end of original is detected by a microswitch in the course of its conveyance and after a predetermined time, conveyor rollers are stopped from rotating so that the original is placed at a predetermined position on the original carriage. In case of such device, the drawbacks noted with respect to the above-described conveyor device are rarely encountered, but if the originals are not placed at an accurate position on the original support bed, namely, if the originals are obliquely placed on the bed or if the originals are obliquely fed by a separation roller, it is not possible to place the originals at an accurate position on the original carriage surface, and thus, proper copying cannot take place to a great inconvenience. SUMMARY OF THE INVENTION It is an object of the present invention to provide a device for automatically and accurately effecting successive conveyance of originals to be copied to the original carriage portion of a copying apparatus and collection of the used originals. It is another object of the present invention to provide a device for automatically placing originals to be copied accurately at a designated position on the original carriage portion of a copying apparatus. It is still another object of the present invention to provide a device for automatically registering originals to be copied at a predetermined position before they are placed on the original carriage portion of a copying apparatus. It is yet still another object of the present invention to provide a device for automatically registering a next original accurately at a predetermined position when an original to be copied rests on the original carriage portion. It is a further object of the present invention to provide an automatic original handling device for reliably bringing originals to be copied into intimate contact with the original carriage surface. Other objects and effects of the present invention will become fully apparent from the following description of the invention taken in conjunction with the accompanying drawings. The above principal objects of the present invention may be achieved by the automatic original handling device which will be described below. According to the present invention, the automatic original handling device for automatically conveying sheet originals to the original carriage surface of a copying apparatus comprises belt conveyor means comprising a belt member passed over at least two rollers, and registration means for registering originals on the belt conveyor means to accurately convey the originals to a predetermined position on the original carriage surface before the originals are conveyed to the original carriage surface by the belt conveyor means. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the automatic original handling device according to the present invention. FIG. 2 is a perspective view of a portion of the automatic original handling device for showing the details of the registration mechanism for originals. FIG. 3 is an enlarged view of a portion of the registration means. FIG. 4 illustrates the manner in which positioning of an original is carried out according to the present invention. FIG. 5 is a perspective view of the direction changing unit of the automatic original handling device according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, it is a perspective view showing an embodiment of the original conveyor device according to the present invention. Designated by 1 is a side plate for supporting the conveyor device and two such plates are provided on the opposite sides. Inwardly of the side plates, there are two roller side plates 4 chiefly supporting rollers 2 and 3. In the present embodiment, five belts 5 are passed over the rollers 2 and 3. An original fed from the left of the drawing by unshown feed means rides on the conveyor belts 5 and is moved with the belts in the direction of arrow A toward an original carriage surface which underlies the conveyor device. Each of the conveyor belts 5 is formed with suitably spaced apart small apertures 6. Inwardly of the conveyor belts 5, there are upper and lower plates 7 and 8 which are secured to the roller side plates 4. The upper plate 7 is formed with a groove 9. The lower plate 8 is formed with a number of apertures 10 which are slightly larger than the apertures 6 in the conveyor belts 5. These apertures 10 and 6 are provided to cause an original to be adsorbed to the conveyor belts by a suction fan 11 disposed centrally of the lower plate 8 so as to prevent the original from dropping off the conveyor belts 5. The upper plate 7 covers the inner side of the belts so as to prevent the original from being blown up by the blast from the suction fan. On the conveyor belts 5 adjacent to their one end, a stop roller 12 is rotatably mounted with respect to the roller side plate 4. The stop roller 12 is used to arrest the original at this position, and is rotated or stopped in synchronism with the rotation or stoppage of the conveyor belts 5. Adjacent to the roller 3 where the conveyor belts 5 turn its direction of movement, there is a unit for ensuring the change of direction of the original. This unit has two direction changing side plates 13 provided inwardly of the roller side plate 4, and rollers 14, 15 and 16 rotatably mounted between these side plates. Of these rollers, the roller 14 has its end rotatably journalled also to the side plates 1 of the conveyor device. Belts 17 are passed over the rollers 14, 15 an 16. The belts 17 overlap the conveyor belts 5 on the roller 3. An original conveyed to the position of the roller 3 is nipped between the belts 5 and 17 to change its direction of movement and is thus conveyed toward the original carriage portion. The conveyor device is driven by a drive motor, not shown. The rotational force of the drive motor is first transmitted to a drive gear 18. The drive gear 18 is mesh-engaged by a conveyor gear 20 and a registration gear 21 both supported on a shaft 19. The conveyor gear 20 transmits the rotation force by the operation of an electromagnetic clutch 22 coaxial therewith. As a result, the conveyor device is operated so that the original fed from the left is conveyed on the conveyor belt 5. On the other hand, the rotational force transmitted to the registration gear 21 is further transmitted to the original registration mechanism of the present invention. Such rotational force is further transmitted to a pulley 26 mounted on a registration shaft 25 via a pulley 23 coupled to the gear 21 and a belt 24 passed thereover. The rotational force is still further transmitted to a wire pulley 28 by the operation of an electromagnetic clutch 27. A length of wire 29 is passed over the wire pulley 28. One end of the wire 29 is secured to a slide bed 34 through a pulley 31 rotatably mounted on a shaft 30, and the other end of the wire 29 is secured also to the slide bed 34 through a rotatable pulley 33 on a shaft 32. The slide bed 34 is slidably mounted on a slide shaft 35, secured to the roller side plate 4, by means of a bearing. Another slide shaft 36 is secured to the other roller side plate 4, and a slide bed 37 is slidably mounted on the slide shaft 36, The slide beds 34 and 37 have a movable plate 38 secured thereto. The movable plate 38 is reciprocally movable along the direction of movement of the conveyor belts 5. Two original registration means having a registration plate 39 are mounted to the movable plate 38. The registration plate 39 has its end projectable from the groove 9 to push the original when the movable plate 38 is moved, thereby registering the original to a predetermined position. The outlines of the original conveyor device according to the present invention have been described above. Description will now be made of the original registration mechanism by reference to FIGS. 2 and 3. In the ensuing description, the method of registerting the trailing end of the original to a predetermined position will chiefly be discussed. FIG. 2 is a perspective view showing the registration mechanism of the present invention. When an orignal is fed to the original carriage portion and stopped there to be optically scanned, the next original comes onto the conveyor belts and is stopped thereon. At this time, the aforementioned electromagnetic clutch 27 is operated to move the movable plate 38 in the direction of arrow C. Thereupon, the registration plate 39 mounted to the lower portion of the movable plate 38 cocks up and the end 39a of the registration plate pushes the trailing end of the original on the belts. When the slide bed 34 supporting the movable plate 38 actuates a microswitch 40 or 41 provided on the lower plate 8 of the conveyor device, the electromagnetic clutch 27 is deenergized. Upon deenergization of the electromagnetic clutch 27, the movable plate 38 is returned to its initial position by the force of a spring 43 mounted between a fixed plate 42 secured to the upper plate 7 of the conveyor device and the slide bed 34. Instead of providing the spring 43, it is also possible to rotate the pulley 28 in the opposite direction, thereby returning the movable plate 38 to its initial position. The position whereat the microswitch 40 or 41 is installed may be predetermined in accordance with the size or length of the original. Thus, the original has its trailing end registered on the belts in accordance with the position of the microswitch. In the shown embodiment, two microswitches are provided and one of these is selectively used. A greater number of microswitches may be installed and the point whereat the registration plate is reverted to backward movement may be changed in accordance with the size of the original. It is also possible to vary the operating time of the electromagnetic clutch 27 in one way or other to thereby change the position of movement of the movable plate 38, namely, the registerted position of the original. FIG. 3 shows detailed construction and operation of the registration means mounted to the movable plate. The registration plate 39 is supported by a shaft 45 passing through a support plate 44. The registration plate 39 is biased in the direction of arrow by a spring 46. When an original is being conveyed, the registration plate 39 normally assumes its prone position by its lower end being pushed by a release plate 47 secured to the conveyor device. When the conveyor belts are stopped and the registration plate pushes the trailing end of an original to register it to a predetermined position, the registration means is moved in the direction of arrow C. At this time, the prone registration plate 39 is gradually released from the release plate 47 to cock up and strike against a stop 48 provided on a support plate 44, so that the registration plate is stopped. The end 39a of the registration plate 39 is projected through the groove 9 (FIG. 1) in the upper plate 7 of the conveyor device and in this position, the registration plate goes to push the original 49. This registration plate can push and register sheet originals as well as fairly thick and heavy originals by suitably adjusting the strength of the spring 46. The registration of the original by the registration plate 39 is not restricted to the aid of the spring bias of the spring 46 but the lower end of the registration plate 39 may be formed as a "weight" or may have attached thereto a "weight" to accomplish the registration of the original. As a further alternative, the registration plate or similar projection may be designed to be vertically projected from the movable plate when the original is to be registered. Having registered the original to its predetermined position, the registration means is returned to its initial position by the action of the spring 43, as already noted. The registration plate 39 has its lower end portion again pushed by the release plate 47 to assume its prone position. Thus, the registration plate 39 does not interfere with the movement of a next oncoming original even if it is fed onto the conveyor belts by feed means. Reference is now had to FIG. 4 to describe how the original registered to its predetermined position is transported to the original carriage portion of the copying apparatus. Usually, the original carriage portion 50 has a transparent glass plate 51 for the exposure to original image and a support plate 52 provided with index marks for designating the sizes of the originals. The support plate 52 supports the transparent glass plate 51. The glass 51 is provided with an unshown optical system for scanning an original. The roller 53 of the conveyor device is brought into contact with the original carriage portion 50 with the conveyor belts 5 interposed therebetween, but a gap is provided between the belts adjacent to the other roller 3 and the original carriage portion. More specifically, if the present conveyor device is sectioned along the direction of movement of the conveyor belts, it will be seen that there is formed a wedge-shaped space between the original carriage portion and the conveyor belts. The original is conveyed through such space and stopped at a predetermined position on the transparent glass 51. At this time, the roller 3 is lowered to enable the conveyor belts to hold down the original against the transparent glass. The upward and downward movement of this roller 3 will further be described. When the original 54 on the original carriage portion 50 is being optically scanned at this position, the next original 49 on the now stationary conveyor belts 5 has its trailing end pushed by the registration plate 39 so that it is registered to its predetermined position. When the optical scanning has been completed, the electromagnetic clutch (FIG. 1) is operated in synchronism therewith to rotate the roller 2 and thus the conveyor belts 5 again. By this, the original 54 on the original carriage portion 50 is transported from this conveyor device onto a discharge tray or the like. In the meantime, the next original 49 is transported to the original carriage portion 50 and when the trailing end thereof has come to the trailing end reference position E, the conveyor belts 5 are controlled so as to be stopped. Such control may be accomplished by rotating the drive motor by an amount corresponding to the distance of movement of the original 49 from its trailing end registered position to its trailing end reference position E, or by operating the electromagnetic clutch 22 (FIG. 1) which transmits rotation force to the roller 2 for a time during which the belts are moved over said distance. The trailing end registered position can be readily seen from the position of the preset microswitch. Depending on the apparatus, the leading end of an original is registered to the leading end reference F of the original carriage portion 50. In such case, the trailing end of the original 49 is pushed by the registration plate 39 and the leading end thereof is caused to bear against the stop roller 12, thereby registering the original at its leading end. The original thus registered can be conveyed accurately from its leading end registered position to the leading end reference F of the original carriage portion by the same method as that already described. In either of the above-described trailing end or leading end registration, the conveyance of the next original is controlled so that the original 49 is stopped short of the stop roller 12 with the trailing end thereof stopped at a point slightly past the groove 9, as shown. In the case of the trailing end registration, the position of the microswitch for changing over the movement of the registration plate 39 is selected so that the registration plate 39 does not push the original so as to strike against the stop roller 12. Likewise, in the case of the leading end registration, the microswitch installed in accordance with the size of the original must be selected so as not to push the original too much. In the case of the leading end registration, a thin original could be pushed by the registration plate so that the central portion thereof is more or less bulged, but there is no fear that such original is damaged, because it is not held down from above it. Where the original is a thick one, the strength of the spring 46 attached to the registration plate 39 may be adjusted so that the registration plate may assume its prone position after the leading end of the original has come to bear against the stop roller 12. PG,13 According to the present invention, as has hitherto been described, the original is pre-registered to its predetermined position by the registration plate and any positional deviation may be thus corrected, so that the original can be placed at the proper position on the original carriage portion without any deviation by the subsequent conveyance. In the shown embodiment, two registration means are provided on the movable plate, whereas any desired number of such registration means may be provided in accordance with the various sizes of originals. Description will now be made of the direction change unit for changing the direction of the original. FIG. 5 shows an example of the mechanism in which a gap is provided between the conveyor belts 5 and the original carriage portion in the position as shown in FIG. 1 to ensure smooth conveyance of the originals. Cam followers 56 are provided on the shaft 55 of the roller 3 at the opposite ends thereof, and camming surfaces 57 in contact with the cam followers 56 are provided in a portion of the direction changing side plates 13. When the conveyor belts are stopped and an original has come to rest at a predetermined position on the original carriage portion, the direction changing side plates 13 are rotated in the direction of arrow G about the shaft 58 of the roller 14 by means of unshown cam or the like, whereby the cam followers 56 are lowered in the direction of arrow H along the camming surfaces 57. Thus, the roller 3 is lowered into intimate contact with the original on the original carriage portion. When this roller 3 has been lowered, the image formation process such as the optical scanning or the like is carried out in the image formation apparatus such as copying machine or the like. Immediately after completion of the image formation, the direction changing side plates 13 are rotated in the opposite direction to the arrow G by the action of a cam, not shown. By this, the camming surfaces 57 of the direction changing side plates are also moved to move the cam followers 56 upwardly. Thus, the roller 3 moved upwardly. In this manner, the original can be positively brought into intimate contact with the original carriage portion when placed thereon. Moreover, during the conveyance of the original, the roller 3 is moved upwardly to form a gap between the conveyor belt and the original carriage portion so as to permit the original to be conveyed through such gap while being sucked. As has hitherto been described in detail, the present invention pre-registers an original on the conveyor belts when the original is conveyed toward the original carriage portion and therefore, the original can be readily placed at a proper position on the original carriage portion simply by conveying the registered original over a predetermined distance. It is also possible to eliminate the drawback that the original is obliquely conveyed toward the original carriage portion to prevent proper copying from being performed. In addition to these advantages, the present invention enables the original to be registered to the trailing end reference or the leading end reference in accordance with the type of the copying apparatus. Moreover, when optical scanning is taking place with an original resting on the original carriage portion, the next original can be registered to save the time and enhance the copying efficiency.	This specification discloses an automatic original handling device for use with a copying apparatus and for automatically placing an original to be copied at a predetermined position on the original carriage surface of the copying apparatus. The original conveyor means of the device is provided with registration means for pushing the trailing end of the original to register the trailing end to a predetermined position on the conveyor means or provided with the registration means and restraining means for stopping the original moved by the registration means to register the leading end of the original at a predetermined position, thus registering the trailing end or the leading end of the original at the predetermined position, whereafter the original is conveyed over a predetermined distance and placed at a proper position on the original carriage surface.	1
BACKGROUND AND OBJECTS 1. Field of the Invention The present invention relates to an enclosed sanitary facility for animals, and more particularly to an enclosed indoor commode for use by cats. 2. Description of the Prior Art It is well known to provide indoor toilet facilities for household pets, particularly cats. Such facilities are normally used to contain a loose, absorbent material, such as granulated clay, for receiving animal excretions. The material is commonly referred to as litter. It has previously been known to provide litter containers which are completely enclosed but which include an opening for providing access for the animal to the enclosed space. Examples of completely enclosed litter containers are found in U.S. Pat. No. 3,246,630 to Dearing et al, U.S. Pat. No. 3,885,523 to Coleman, and U.S. Pat. No. 394,258, filed Sept. 5, 1973, and now abandoned. These devices include upper and lower enclosure portions which are removably joined together. The lower enclosure portion contains the litter, and the upper enclosure portion may be separated therefrom to allow for cleaning of the container and changing of the litter. A drawback of some known devices having separable upper and lower enclosure portions is that certain pets have a tendency to spray urine against the inside walls of the container. This urine may leak from the joint between the enclosure portions to the exterior of the container and it may also collect in the region of the joint and cause odor problems. Preventing urine from collecting in the joint or leaking therefrom conflicts with providing low cost construction, ease of separability of the enclosure portions and use of a resilient, unbreakable, thin walled material in the construction of the container. While the aforementioned U.S. Patent to Coleman shows a construction which may minimize the problem of urine leakage or collection of urine in the joints between the enclosure portions, the construction does not provide the advantages of simplicity, low cost, ease of manufacturing, ease of separation of the enclosure portions, and use of a resilient material in construction. In this regard, it is advantageous to provide a device wherein each enclosure portion has a one-piece construction and is molded from low density polyethylene or other resilient plastic material. In such a device it is desirable to provide a widened flange or widened rim portion on each enclosure portion. The rim and flange strengthen and add rigidity to the enclosure portions and provide a relatively rigid bearing region for joining the two enclosure portions together. Also, the widened rim portion on the upper enclosure portion, particularly when it fits over the outside of the widened flange portion of the lower enclosure portion, as here, provides a desirable handle or gripping surface for removing the upper enclosure portion from the lower enclosure portion to clean the litter container. It is also desirable, in a construction of the foregoing type, to provide a relatively free fit between the upper and lower enclosure portions. This provides ease of manufacturing and lower cost. It also ensures easy separability of the upper enclosure portion from the lower enclosure portion. This type of free fitting construction, however, while having important advantages, may lead to the urine collection and urine leakage problem discussed above. OBJECTS OF THE INVENTION It is therefore an object of the present invention to overcome the foregoing drawbacks and provide a litter container having upper and lower enclosure portions which may fit together relatively freely or loosely so as to be easily separated from each other but wherein urine is prevented from escaping or collecting in the joint between the enclosure portions. It is a further object of the invention to provide an animal litter container which is of a simple and inexpensive construction with easily separable upper and lower enclosure portions and wherein urine is prevented from escaping from or collecting in the joint between the enclosure portions. It is a further object of the invention to provide an animal litter container wherein urine entering the region of the joint between the upper and lower enclosure portions is directed away from the joint and toward the bottom of the lower enclosure portion which contains the litter. It is another object of the invention to provide an animal litter container with widened rims or flanges which both provide a bearing region for joining the upper and lower enclosure portions together, provide a handle or gripping area for easy separability of the enclosure portions, and which also direct urine toward the bottom of the lower enclosure portion and away from the bearing area in the joint between the two enclosure portions. It is a further object of the invention to provide an animal litter container having easily separable enclosure portions which may be constructed entirely of a resilient, plastic material and wherein urine is prevented from escaping from or collecting in the joint between the enclosure portions. These, and other objects, advantages, and features of the present invention will be apparent from the specification which follows and from the drawing. SUMMARY To overcome the drawbacks of the prior art and to achieve the foregoing objects, the litter container of the present invention includes upper and lower enclosure portions which define an enclosed space when coupled together. One of the enclosure portions includes a means for providing access for an animal to the enclosed space. Also included is means between the upper and lower enclosure portions for coupling the enclosure portions together, the upper enclosure portion including a portion projecting into the enclosed space. This projecting portion extends substantially entirely around the upper enclosure portion and has a free extremity which is spaced from the coupling means. The upper enclosure portion includes a main body portion and a widened rim portion disposed outwardly of the main body portion. The widened rim portion extends about the entire periphery of the upper enclosure portion, one part of the widened rim portion providing the projecting portion. The projecting portion may take the form of a downwardly convex convolution in the widened rim portion, the crest or vertex of the convolution providing the aforementioned free extremity. The widened rim portion also includes a bearing portion which engages with an upper edge of the lower enclosure portion to provide the coupling between the enclosure portions. The bearing portion of the upper enclosure portion is disposed outwardly of the projecting portion in the widened rim portion and at a level above the projection portion. The bearing portion is provided by a downwardly concave convolution in the widened rim portion, and the vertex of this convolution provides the bearing portion against which the upper edge of the lower enclosure portion engages. When urine is directed into the region between the upper and lower enclosure portions, it will flow by gravity to the free extremity or vertex of the projecting portion and drip therefrom. Since the bearing portion is spaced outwardly of the free extremity of the projecting portion, urine cannot flow to the bearing portion. The lower enclosure portion includes a main container portion and a widened flange portion, the widened flange portion extending about the entire periphery of the lower enclosure portion. The widened flange portion includes an outwardly extending shoulder, and a generally vertical flange wall with an upper edge. The upper edge bears against the bearing portion of the upper enclosure portion to couple respective portions together. The outwardly extending shoulder has an undulating configuration which includes an inner, upwardly bowed portion adjacent the main container portion and an outer, downwardly bowed portion adjacent the outer, vertical flange wall. A plurality of downwardly and inwardly sloping channels extend from the downwardly bowed portion of the shoulder, through the upwardly bowed portion thereof, and to the main container portion. Urine dripping from the free extremity of the projecting portion on the upper enclosure portion will enter into the downwardly bowed portion of the widened flange on the lower enclosure portion and will drain through the channels into the litter containing cavity of the lower enclosure portion. Each of the enclosure portions is of a one-piece construction. The enclosure portions are molded from a resilient plastic material, preferably low density polyethylene. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a front elevation of the animal litter container of the present invention; FIG. 2 is a plan view of the animal litter container of FIG. 1; FIG. 3 is a plan view of the lower enclosure portion of the animal litter container of FIG. 1 with the upper enclosure portion removed; FIG. 4 is a horizontal sectional view taken on the line 4--4 of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the following description and in the drawing, like reference characters refer to like features or elements among the various figures of the drawing. Referring to the drawing, the overall animal litter container is generally referred to by reference character 10. The container includes an upper enclosure portion 12 and a lower enclosure portion 14. Enclosure portions 12, 14 may be coupled together as shown in FIGS. 1 and 4 to define a space which is completely enclosed except for an opening 16, which opening provides access for an animal to the enclosed space. Upper enclosure portion 12 includes a top wall 18, a front wall 20, oppositely disposed side walls 22, and a rear wall 24. Opening 16 is in the front wall 20. Together walls 18, 20, 22 and 24 define a cavity 26 (see FIG. 4) which forms part of the enclosed space defined by the overall container 10. Walls 18, 20, 22 and 24 form the main body portion 28 of upper enclosure portion 12. Extending outwardly from main body portion 28 is a widened rim portion 30. Widened rim portion 30 extends entirely around the periphery of upper enclosure portion 12. Widened rim portion 30 includes a downwardly projecting portion 32 (see FIG. 4) extending entirely around the upper enclosure portion. Projecting portion 32 includes a free extremity 34 disposed in the enclosed space formed by the upper and lower enclosure portions 12, 14. Free extremity 34 is spaced inwardly from the joint or coupling between the enclosure portions. As will be apparent from FIG. 4, projecting portion 32 is defined by a downwardly convex convolution in widened rim portion 30 of upper enclosure portion 12. As will also be apparent from FIG. 4, the free extremity 34 of projecting portion 32 is provided by the vertex or crest of the downwardly convex convolution which forms projecting portion 32. The litter container 10 includes a coupling or joint 36 between the upper and lower enclosure portions. Coupling 36 is provided, in part, by a downwardly concave convolution 38 in the widened rim portion. As will be apparent from FIG. 4 downwardly concave convolution 38 is disposed outwardly of projecting portion 32. Convolution 38 extends entirely around the periphery of upper enclosure portion 12, entirely outside projecting portion 32. The vertex of downwardly concave convolution 38 provides a bearing portion 40 in the upper enclosure portion 12. An upper edge 42 of lower enclosure portion 14 abuttingly engages bearing portion 40 to provide the coupling 36 between enclosure portions 12, 14. Bearing portion 40 extends around upper enclosure portion 12 interiorly of and at a level above the level of free extremity 34 of projecting portion 32. That is, the free extremity or vertex 34 is spaced inwardly from bearing portion 40 and disposed therebelow. Widened rim portion 30 of upper enclosure portion 12 includes an outer vertical rim wall 44, the bottom edge of which has an inwardly extending lip 46 which extends around the entire upper enclosure portion 12. Lower enclosure portion 14 includes a front wall 48, oppositely disposed side walls 50, a rear wall 52 and a bottom wall 54. Together these walls form a cavity 56 (FIG. 4). Cavity 56 forms part of the enclosed space defined by the overall litter container 10. The litter or other absorbent and/or loose material for receiving animal excretions will be contained in cavity 56. A set of surface engaging feet 58 extend downwardly from bottom wall 54. Walls 48, 50, 52 and 54 form a main container portion 59 of lower enclosure portion 14. Extending outwardly from main container portion 59 is a widened flange portion 60. Widened flange portion 60 extends about the entire periphery of lower enclosure portion 14 at the upper end thereof, i.e. the end which engages with the lower end of upper enclosure portion 12. Widened flange portion 60 includes an outwardly extending shoulder 62 and an upstanding vertical flange wall 64. The top of vertical flange 64 forms the aforementioned upper edge 42 which engages with the bearing portion 40 of upper enclosure portion 12 to couple the enclosure portions together. As will be apparent from FIG. 4, the shoulder 62 of widened flange portion 60 has an undulating configuration including an inner, upwardly bowed portion 66 adjacent main container portion 59, and an outer, downwardly bowed portion 68 adjacent vertical flange wall 64. A plurality of downwardly and inwardly sloping channels 70 extend from downwardly bowed portion 68 of widened flange portion 60, through upwardly bowed portion 66 thereof, and to the main container portion 59. Urine, entering into the downwardly bowed portion 68 extending around the lower enclosure portion, will drain through channel 70 into cavity 56 which contains the litter. Each enclosure portion is of a one-piece molded construction. That is, walls 18, 20, 22 and 24 and widened rim portion 30 of upper enclosure portion 12 are all of one piece. Likewise, walls 48, 50, 52, and 54, feet 58, and widened flange portion 60 of lower enclosure 14 are all of one piece. Also, each enclosure portion consists, overall, of a one-piece wall of substantially uniform thickness. Each enclosure portion is constructed entirely of a resilient plastic material, preferably low density polyethylene. The structure described above is particularly suitable for litter containers constructed of such materials, i.e. resilient plastic materials. Such materials have the advantages of ease of molding and unbreakability. Use of resilient plastic materials, however, calls for a construction which will render the respective enclosure portions somewhat rigid in the region where they are coupled together and a construction which is free from close tolerance requirements. Widened rim portion 30 of upper enclosure portion 12 and widened flange portion 60 of lower enclosure 14 achieve the desired rigidity. At the same time, the construction and configuration of the upper and lower enclosure portions in the regions of rim and flange portions 30, 60 is such as to provide relatively freely fitting parts for ease of separation, while at the same time preventing leakage of urine from or collection of urine in the joint between the sections. In this latter regard, any urine sprayed by an animal against the walls of upper enclosure portion 12 and adhering thereto by surface attraction, or any urine sprayed into the region of the joint between the enclosure portions 12, 14, will flow to the free extremity 34 of projecting portion 32 and drip therefrom into the trough formed by the downwardly bowed portion 68 of lower enclosure portion 14. From there the urine will flow through the sloping channel 70 into the cavity 56 containing the litter. Because the portion of widened rim 30 disposed immediately outwardly of projecting portion 32 is at a level above free extremity 34 urine cannot flow upwardly and thence into the region of the joint between the sections. That is, the projecting portion 32, and in particular the free extremity 34 thereof, is spaced from the coupling means between the upper and lower enclosure portions, and this spacing prevents urine from flowing into the coupling means. In this instance, the coupling means includes the bearing portion 40 of the upper enclosure portion 12 and the upper edge 42 of the lower enclosure portion 14. In the preferred embodiment, these are located at a level above the free extremity 34 of the projecting portion 32. In the preferred embodiment, the inwardly extending lip 46 of the outer vertical rim wall 44 of upper enclosure portion 12 engages the vertical flange wall 64 of the lower enclosure portion 14. The lip 46 maintains a spacing or at least a looseness between the major surfaces of rim wall 44 and flange wall 64, as will be apparent from FIG. 4. At the same time, however, lip 46 resiliently and grippingly engages vertical flange wall 64 to hold the enclosure portions together by the force of friction. That is, the lip both maintains a certain degree of freedom between rim 44 and flange 64 to permit relatively easy disengagement of the upper and lower enclosure portions when desired, yet at the same time the lip 46 provides a sufficient grip to normally hold the upper and lower enclosure portions together. The term "enclosed space," when used herein to refer to the space defined by the upper and lower enclosure portions when joined together, includes not only the upper and lower cavities 26, 56 but also the interior space 72 (FIG. 4) extending around the litter container and defined by widened rim portion 30 and widened flange portion 60. It will be understood that the foregoing specification describes only a preferred embodiment which exemplifies the invention, and many modifications, variations, and other embodiments are possible. The invention, of course, is limited only by the scope of the appended claims.	An enclosed litter container for animals, the container having upper and lower enclosure portions coupled together to provide an enclosed space. The upper enclosure portion has an opening therein to provide access for an animal to the enclosed space. The lower enclosure portion defines a cavity for containing litter. The upper enclosure portion includes a widened rim portion, and the lower enclosure portion includes a mating widened flange portion. Part of the widened rim portion of the upper enclosure portion includes a downwardly convex convolution having a vertex or free extremity extending into the enclosed space. The construction prevents urine from collecting in and/or escaping from the joint between the enclosure portions. A series of downwardly sloped channels in the widened flange portion of the lower enclosure portion help direct the urine toward the litter.	0
RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application 60/977,028 filed on Oct. 2, 2007. NOTICE OF COPYRIGHTS AND TRADE DRESS [0002] A portion of the disclosure of this patent document contains material, which is subject to copyright protection. This patent document may show and/or describe matter, which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever. BACKGROUND [0003] This disclosure relates to a system and process for managing photos and specifically to an online system for use by print media and newspapers to directly link a photo of an item for sale with a classified advertisement. SUMMARY [0004] These and other embodiments are described in more detail in the following detailed descriptions and the figures. [0005] The foregoing is not intended to be an exhaustive list of embodiments and features of the inventive subject matter. Persons skilled in the art are capable of appreciating other embodiments and features from the following detailed description in conjunction with the drawings. DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a block diagram of a system for photo management system. [0007] FIG. 2 is a flow chart of a process for managing photos. [0008] FIG. 3 is a flow chart of a process for accessing a photo management system by a registered user. [0009] FIG. 4 is a flow chart of a process for accessing a photo management system by an unregistered user. [0010] FIG. 5 is a flow chart of a process for accessing a photo management system by a registered advert user. [0011] FIG. 6 is a flow chart of a process for accessing a photo management system by an unregistered advert user. [0012] FIG. 7 is a flow chart of a process for accessing a photo management system by a print media business. DETAILED DESCRIPTION [0013] Representative embodiments according to the inventive subject matter are shown in FIGS. 1-7 , wherein the same or generally similar features share common reference numerals. [0014] FIG. 1 is a block diagram of a photo management system which may include at least one server for storing and managing photos submitted by users. Although FIG. 1 shows a single server, the functions of the photo management system may be partitioned between a plurality of servers, some of which may be dedicated to specific functions, such as a Web server or a file server. In this context, a “server” is any computing device capable of performing all or part of the functions of the photo management system. [0015] The server may be connected to at least one network, which may be the Internet. The server may be connected to other networks, such as a local area network, storage network, or wide area network, in addition to the Internet. Registered and unregistered users may interact with the server by means of network-connected devices or by means of mobile communication devices via an intermediary wireless service provider (WSP). Although FIG. 1 shows a laptop computer as an example of a network-connected device, any network-connected device may be used including personal computers, tablet computers, personal digital assistants, and any other network-connected devices. Similarly, although FIG. 1 shows a cellular phone as an example of a mobile communication device, other mobile devices, such as wireless email appliances and two-way messaging pagers, may be used. The server may interact with newspaper or other print media users by means of the Internet or other network. [0016] The server may be connected with, or may include, an interactive voice response (IVR) system to allow interaction with users who are unable or unwilling to use text messaging or other simple message service (SMS) messages from a mobile communication device. [0017] FIG. 2 is a flow chart of a process for managing photos. This process may be consistent with the photo management system of FIG. 1 . [0018] The process for managing photos may begin when a seller, having an item for sale, contacts a newspaper or other print publication to place a classified advertisement. The print publication may offer the seller the opportunity to have one or more photographs of the item connected to the print advertisement. The print publication may explain that, for a small additional fee, a photo of the item may be sent to prospective buyers via the buyer's mobile communication device or may be accessed via a website. [0019] If the customer accepts the additional service, the photo management service fee may be included in the total advertisement fee and billed by the print publication through their traditional order processing methods. The print publication may conclude the sale using their existing processes and may inform the seller that instruction for uploading the photo(s) of the item will be provided by email. [0020] The print publication may then establish a discrete code for the advertisement and submits information on the seller and the advertisement to the photo management system. Conveniently, the seller's phone number may be used as the discrete code. [0021] Upon receipt of the information from the print publication, the photo management system may establish an account for the seller as a registered advertising user. The photo management system may then send an email message or a text message to the registered advertising user (the seller) including instructions for submitting photos. [0022] The registered advertising user may then upload one or more photos to the photo management system. Photos may be submitted directly from the registered advertising user's cell phone, by e-mail attachment, or via the photo management system Web site. [0023] Potential buyers may then view photos using their cell phones. For example, the potential buyers may dial a five-digit short code to access the photo management system and then enter the phone number printed in a classified advertisement to access the appropriate photos. [0024] The photo management system may not be limited to receiving and managing only photos specifically linked to advertisements. For example, the photo management system may be used to manage photos for previously registered users who do not have current print media advertisements. [0025] FIG. 3 is a flow chart of a process that may be used by a normal registered user, herein termed a “CPIXX user”, to access the photo management system. The CPIXX user may add multiple photos to a profile associated with the registered user (herein termed a “CPIXX profile”) and stored on the server. A CPIXX user may add photos to their CPIXX profile by means of text messages from a mobile communication device, by means of a network-connected device, or by means of e-mail. [0026] A CPIXX user may take a picture from a mobile device and sent it to their CPIXX profile using a gateway number provided by their mobile service provider. The Mobile service provider may receive the photo and the gateway number sent by user. The Mobile service provider may authenticate the gateway number. If the gateway number is correct, the service provider may pass the photo and the user's mobile number to the photo management system with a parameter which contains type of data. (0=Photo and 1=Text message). If the gateway number is incorrect, the mobile service provider may send an “incorrect gateway number” message to the CPIXX user. [0027] When the photo management system receives the data from the mobile service provider with the parameter, the photo management system may authenticate the CPIXX user by his/her mobile number or some other method. If the CPIXX user is registered, the photo management system may store the photo into the CPIXX user's profile in the database. If the CPIXX user is unregistered, the photo management system may send an “invalid user” message to mobile service provider and mobile service provider may forward the message to mobile user. [0028] Alternatively, a CPIXX user may upload photos to his/her CPIXX profile using a network-connected device. The CPIXX user may first login to the photo management system by passing credentials which may include a user name and a password. The photo management system may then authentic the credentials entered by user. If the entered user name and password are valid, the CPIXX user may be enabled to add new photos to their CPIXX profile. [0029] Additionally, a CPIXX user may also upload photos to their CPIXX profile using e-Mail. The CPIXX user may attach one or more photos to an email, include the CPIXX number as the email subject and send the email message to the photo management system. The photo management system may parse the received email message to retrieve the CPIXX number and the attached photos. The photo management system may authenticate the CPIXX number. If the CPIXX number is valid, the photo management system may add the attached photos to the CPIXX user's profile. [0030] FIG. 4 shows a flow chart of the process that may be used by an unregistered user to access the photo management system. An unregistered user may view permitted photos uploaded to the photo management system by registered CPIXX users. An unregistered user can view a CPIXX user's photos using text messages from a mobile communication device, using a computer connected to the network, or using an interactive voice response system (IVR). [0031] An unregistered user may pass a CPIXX number and a gateway number as SMS messages to their mobile service provider. The unregistered user may also pass a photo number along with the CPIXX number and the gateway number to view a selected photo instead of all photos. When the mobile service provider receives the CPIXX number, the gateway number and the optional photo number sent by the unregistered user, the mobile service provider may authenticate the gateway number. If the gateway number is correct, the mobile service provider may pass the CPIXX number, the gateway number and the optional photo number to the photo management system. If the gateway number is incorrect, the mobile service provider may send an “incorrect gateway number” message to the unregistered user. [0032] When the photo management system receives data from mobile service provider, the photo management system may check availability of the designated CPIXX user. If the CPIXX user is registered, the photo management system may fetch the selected photo if a photo number was provided, or all permitted photos in the CPIXX user's profile from database and send them to the unregistered user's mobile device. If the provided CPIXX number does not correspond to a registered user, the photo management system may send an “invalid user” message to the mobile service provider and the mobile service provider may forward the message to mobile user. [0033] Unregistered users who are unable or unwilling to send SMS messages, may access photos by calling a dedicated phone number and using an IVR system to enter the CPIXX number and optional photo number. After the validity of the CPIXX number is checked, the photos may be sent to the unregistered user's mobile device as previously described. [0034] Alternatively, an unregistered user may view a registered CPIXX user's photos from a device connected to the network by accessing the photo management system web site and entering a CPIXX number. The photo management system may check if the CPIXX number is valid or not. If CPIXX number is valid, the photo management system will show photos to the unregistered user. [0035] FIG. 5 shows a flow chart of the process that may be used by an registered advertising user to access the photo management system. A registered advertising user is a registered user who has purchased an advertising package from a newspaper or other print media. A registered advertising user can upload unlimited photos to his/her CPIXX profile, but can connect photos to advertisements only as defined in the advertising package. A registered advertising user may access the photo management system and upload photos using three techniques that are essentially the same as those previously described in conjunction with FIG. 3 . Once photos are uploaded, the registered advertising user can connect specific photos to advertisements as permitted by the advertising package. [0036] FIG. 6 shows a flow chart of a process that may be used by an unregistered advertising viewer to access the photo management system. The process may be essentially the same as that described in conjunction with FIG. 4 , except that the unregistered advertising viewer may obtain a CPIXX number from a printed classified advertisement, and the CPIXX number may be directed to a specific advertisement, rather than to a registered user. [0037] FIG. 7 shows a flow chart of a process that may be used by a newspaper user to access the photo management system. In this context, “newspaper user” is intended to encompass any form of print media user. A newspaper user may access photo management system by means of a network-connected device running a suitable Web application. [0038] The newspaper user may first login to the photo management system by passing credentials such as a user name and a password. The photo management system may authenticate the credentials entered by the newspaper user. If the credentials are valid, the newspaper user may be allowed to access several program modules to manage advertising users and advertising packages. [0039] Persons skilled in the art will recognize that many modifications and variations are possible in the details, materials, and arrangements of the parts and actions which have been described and illustrated in order to explain the nature of the inventive subject matter, and that such modifications and variations do not depart from the spirit and scope of the teachings and claims contained therein. [0040] All patent and non-patent literature cited herein is hereby incorporated by references in its entirety for all purposes. [0041] While the inventor understands that claims are not a necessary component of a provisional patent application, and therefore has not included detailed claims, the inventor reserves the right to claim, without limitation, at least the following subject matter.	A photo management system is described herein consisting of a server, a mobile device, and the internet; furthermore systems and software located on the server and the mobile device provide connectivity and functionality for the exchange of photos.	6
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 12/205,979 filed Sep. 8, 2008, whose contents are incorporated herein by reference and which in turn claims the benefit of priority from U.S. provisional patent application No. 61/086,819, filed on Aug. 7, 2008, the contents of which are hereby incorporated herein by reference, and a continuation-in-part of international patent application no. PCT/US2009/049741 filed Jul. 7, 2009, the contents of which are incorporated herein by referent and which in turn claims priority from U.S. patent application Ser. No. 12/205,878 filed Sep. 8, 2008 and provisional patent application Ser. No. 61/086,819 filed Aug. 7, 2008. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a hybrid heating apparatus to heat potable water via “free heat”, i.e., waste heat recovered by heat recovery units (such as refrigeration units) and heat from insolation units (such as by solar collection units). A single controller directs operation of a single pump to circulate fluid between at least one heat exchanger and each of the heat recovery units and insolation units and directs operation of valves to allow the fluid to be circulated to become heated before reaching the heat exchanger, which heat exchange with the potable water heats the same. [0004] 2. State of the Art [0005] Commercial and residential facilities and dwellings include various systems for heating potable water. In generally, they primarily rely on a conventional water heater that includes either a fossil fuel (oil or natural gas) furnace or boiler or an electric water heater, although an increasing number of such facilities and dwellings have turned to a solar water heater to satisfy their demand for heating potable water to the extent feasible. If the solar water heater cannot meet the demand for potable water heating, then the conventional water heater is operated to satisfy the demand. [0006] A solar water heater may be operated in either a closed loop system or an open loop system to heat potable water stored in a tank. In an open loop system, potable water to be heated is pumped from the tank directly to the solar water heater and back. In a closed loop system, glycol or other kind of fluid having a lower freeze temperature than that of water is pumped to the solar water heater for heating and pumped back to a heat exchanger for heating the potable water in the tank. In climates susceptible to freezing outdoor temperatures, the closed loop system for the solar water heater is used. In climates that are not susceptible to freezing outdoor temperatures, the open loop system may be used for the solar water heater. [0007] In the case of a dedicated solar water heater, the piping may become cold when exposed to cold outdoor temperatures overnight when there is no insolation. At the time of sunrise (or later if they do not face the morning sun), the solar collectors can start again to heat fluid through insolation, but the solar water heater would be operating under a cold start and thus will need to heat the cold fluid circulating in the piping to a higher temperature before it can attempt to satisfy a demand for heating potable water. [0008] Installation and operating costs affect the economic feasibility of incorporating a solar water heater into an existing commercial and residential facility and dwelling to satisfy needs to heat potable water. Thus, the need to heat circulating fluid in piping from a cold start adversely affects the economics of heating potable water by insolation since the conventional water heater will need to operate that much longer until the cold start condition is overcome. Further, the cost for installation and operation of a dedicated pump (and heat exchanger in the case of a closed loop) for the solar water heater adversely affect the economics of heating potable water by insolation. [0009] JP2004012025 proposes an efficient hybrid system that improves the relationship between respective pieces of equipment in a solar system and a cogeneration system by reducing carrier power by inverter control. The hybrid system includes a solar heat collector, a heat storage tank, a heat exchanger to supply hot water, a hot water storage tank, an auxiliary boiler, a heat exchanger for collecting waste heat, a non-utility generator, an absorption type refrigerator, a refrigerating tower, a heater exchanger for heating, a system connection board for controlling the drive of each piece of equipment and a DC power supply board. The overall efficiency of operation is improved when both a solar heat collector and a refrigerant waste heat collector are used to heat water through respective heat exchangers as a supplement to a conventional boiler. However, the economics of such a system is adversely impacted by installing and running respective pumps and using respective heat exchangers for each water heating system, i.e., solar insolation, waste heat recovery, auxiliary boiler, etc. [0010] It would be desirable to reduce the overall installation and operating costs to heat potable water that uses “free heat” from a solar water heater and refrigerant waste heat recovery units (HRU) by integrating them rather than keeping them as separate, stand-alone water heating systems. SUMMARY OF THE INVENTION [0011] A water heating apparatus is provided for controlling the heating of potable water in commercial or private dwellings with improved energy efficiency. The water heating system includes a tank that stores potable water in fluid communication with a potable water source, a refrigeration unit that circulates refrigerant for air conditioning or other refrigeration purposes, a heat recovery unit (HRU) that transfers heat from the circulating refrigerant of the refrigeration unit to the water stored in the tank via a heat exchanger, a solar water heater unit that extracts heat from insolation and transfers the extracted heat to the water stored in the tank preferably also via the same heat exchanger, and at most one circulating pump to circulate fluid between the heat exchanger and each of the HRU and preferably also the solar water heater (if in a closed loop system). [0012] The refrigeration unit preferably includes circulating refrigerant, a compressor for compressing the refrigerant, a fan and an expansion valve for cooling the refrigerant, and an evaporator section that absorbs heat from a refrigeration area to cool the refrigeration area. [0013] A single circulating pump is operated to circulate a heat transfer fluid between a heat exchanger and each of the heat recovery units. The heat exchanger exchanges heat with potable water stored in a tank. [0014] The solar water heater unit includes a solar collector that extracts energy from insolation. If the solar water heater unit is in a closed loop, as are the heat recovery units, then the same circulating pump is operated to circulate the heat transfer fluid to the solar water heater to heat the heat transfer fluid as is used to circulate the heat transfer fluid between the heat exchanger and each of the heat recovery units. Otherwise, the solar water heater unit is in an open loop in the sense that potable water is circulated directly from the tank to the solar water heater to effect heating of the potable water directly. [0015] The refrigeration unit, heat recovery unit, and solar water heater unit each include measuring means for measuring temperature, pressure, or other parameters at various locations in the system, and control means for controlling their operation based on the measured parameters to maximize the energy efficiency, hot water capacity, and longevity of the system while reducing the system's operational costs and fuel consumption. [0016] The refrigeration unit preferably includes a fan control means which operates to deactivate (turn off) the cooling fan of the refrigeration unit when the refrigerant is sufficiently cooled on account of the operation of the heat exchanger in transferring heat away from the refrigerant to the water in the tank, and operates to activate (turn on) the cooling fan of the refrigeration unit when additional cooling is needed. [0017] The heat recovery unit preferably includes HRU control means which operates to activate the heat recovery unit to circulate the first heat transfer medium in the second fluid loop when in an open loop situation (1) the temperature of the water in the second fluid loop becomes so low that it is in danger of freezing; and (2) when the difference between the temperature of the second heat transfer medium at the HRU exceeds the temperature of the potable water in the tank by a predetermined amount (e.g., 8-24.degrees. Fahrenheit). During normal operation, the temperature of the refrigerant between the HRU and the heat exchanger will generally be higher than the temperature of the water in the tank, and the water temperature in the tank will generally be below the maximum temperature desired. Thus, the heat exchanger operates to transfer energy from the refrigerant (which would otherwise need to be expelled to the atmosphere through the use of the fan) to the water in the tank, thereby reducing the fan's operation requirements. [0018] The solar water heater unit preferably includes solar control means which operates to activate the solar water heater unit to circulate the second heat transfer medium in the third fluid loop when two conditions are met: (1) the difference between the temperature of the second heat transfer medium at the solar collector exceeds the temperature of the potable water in the tank by a predetermined amount (e.g., 8-24 degrees Fahrenheit); and (2) the temperature of the potable water in the tank is below the maximum tank temperature desired (e.g., below a maximum tank temperature that is less than 200 degrees Fahrenheit). The first condition allows for the activation of the solar water heater unit when efficient heat transfer can take place. The second condition is when tank temperature is above 185 degrees Fahrenheit controller 58 activates 3-way valve 72 A to dissipate the heat to 71 (heat dump), until the tank temp is below 175 degrees Fahrenheit. The third condition prevents the water in the tank from exceeding a maximum temperature. A relief valve is provided to allow for the removal of a portion of the second heat transferring medium from the third fluid loop in the event that the second heat transferring medium gets too hot at the solar collector. [0019] In other embodiments, an additional tank is utilized for storing the potable water. The additional tank is in fluid communication with both the tank (which operates as a preheater tank) and the potable water source, and bypass valves are provided which may be set to enable the potable water to bypass the tank and flow directly into the additional tank. [0020] Additional objects, advantages, and embodiments of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures. BRIEF DESCRIPTION OF THE DRAWINGS [0021] FIG. 1 is a schematic depiction of an exemplary embodiment of a water heating system according to the present invention. [0022] FIG. 2 is a table describing the function of the fan control means of the refrigeration unit of the invention. [0023] FIG. 3 is a table describing the function of the water heating system control means of the solar water heater unit and HRU of the invention. [0024] FIG. 4 is a schematic of the circuitry of an embodiment of the operational control of the fan of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0025] Turning now to FIG. 1 , a water heating apparatus or system 110 of the present invention is a two-tank system that includes a pre-heat tank 112 - 1 , a conventional heating tank 112 - 2 , and a bypass system 180 . The conventional heating tank 112 - 2 in fluid communication with a source 14 of potable water such as, but not limited to, a well or a city water source. The tank 112 - 1 is configured to place water stored therein is fluid communication with a heat recovery unit 16 , a solar water heater unit 18 , and a heating element 120 . [0026] The system is configured to heat the potable water in the pre-heat tank 112 - 1 by using heat available from free sources (e.g., refrigeration and solar units) in conjunction with the conventional heating element 120 to provide an energy efficient hot water heating system 110 , a conventional heating tank 112 - 2 , and a bypass system 180 . The conventional heating tank 112 - 2 includes a conventional heating element 120 , which may be an electrically powered element, a gas-burning element, an oil-burning element, and combinations thereof. The combination of the pre-heat tank 112 - 1 with the heating tank 112 - 2 allows the system 110 to maximize the collection and storage of heat from the heat recovery unit 16 and the solar water heater or solar collection unit 18 . [0027] The heat recovery unit 16 of the system is in a heat exchange relationship with a conventional vapor compression refrigeration unit 22 such as, but not limited to, an air conditioner, a refrigerator, a freezer, a heat pump, or equivalent refrigeration units known in the art. The heat recovery unit 16 includes a circulating pump 54 and a valve 74 A, which circulates fluid medium from the tank 112 - 1 through a flow loop 17 , a heat exchanger 26 , and a first controller 58 . When heat is available from the vapor compression refrigeration unit 22 , a controller 58 is configured to activate the pump 54 and a valve 74 A, to pump the fluid medium from the tank 112 - 1 through the heat exchanger 26 and back into the tank 112 - 1 . [0028] The refrigeration unit 22 includes a flow loop 19 for circulating refrigerant. A compressor 32 operably coupled to the flow loop 19 compresses the refrigerant and passes the compressed refrigerant to a condenser 34 . The condenser 34 is also operably coupled to the flow loop 19 and includes a cooling fan 36 to force outside air 38 across the condenser 34 to remove heat from the refrigerant within the flow loop 19 . [0029] Thus, the refrigeration unit 22 typically consumes electrical energy to operate the cooling fan 36 to expel waste heat to the outside air 38 . The compressed, condensed refrigerant is then expanded in an expansion valve 40 to a lower temperature, and then passed through an evaporator 42 . The evaporator 42 includes a blower unit 44 , which blows inside air 46 from a conditioned space across the evaporator 42 . The refrigeration unit 22 thus provides conditioned air to a conditioned space. [0030] The heat exchanger 26 of the heat recovery unit 16 is in heat exchange communication with the refrigerant in the flow loop 19 between the compressor 32 and the condenser 34 , which is generally at a high temperature. The heat exchanger 26 operates to transfer waste heat (which is typically removed from the refrigerant by the fan 36 in the prior art) to the water in tank 112 - 1 , which will generally be at a lower temperature than that of the refrigerant between the compressor 32 and the condenser 34 . The heat exchanger 26 includes a first flow path 19 a, which is part of the flow loop 19 of the refrigeration unit 16 , and a second flow path 17 a which is part of the flow loop 17 of the heat recovery unit 16 and in fluid communication with the first flow path 19 a. The heat recovery unit 16 removes heat from the refrigerant in the flow loop 19 of the refrigeration unit 22 and in fluid communication with the potable water in the tank 12 , which also reduces the typical cooling requirements of the fan 36 . [0031] The operation of the controller 58 of the heat recovery unit 16 of the system is best understood with reference to FIG. 1 . The controller 58 activates the circulation pump 54 and a valve 74 A, to circulate a fluid medium (heat transfer fluid) from the tank 112 - 1 through the heat exchanger 26 when heat is available from the refrigeration unit 22 . For example, the controller 58 can receive a first sensor input 69 indicative of a condition of the refrigerant in the refrigeration unit 22 such as, but not limited to, a temperature signal, a pressure signal, or other signals conveying information related to the refrigerant's properties. When the first input 69 reaches a predetermined level indicating that heat is available from the refrigeration unit 22 , the controller 58 may activate the circulation pump 54 and a valve 74 A. [0032] The controller 58 is also preferably configured to deactivate the circulating pump 54 and a valve 74 A, to cease circulating fluid medium from the tank 112 - 1 through the heat exchanger 26 when the water within the tank 112 - 1 reaches a predetermined temperature. For example, the controller 58 may receive a second sensor input 68 indicative of the water temperature within the tank 112 - 1 . When the second sensor input 68 reaches a predetermined level, the controller 58 deactivates the circulation pump 54 and a valve 74 A. In one example, the second sensor input 68 may be a temperature signal and the predetermined level might be 155 degrees Fahrenheit (F). [0033] The controller 58 may also be configured to activate the circulating pump 54 and a valve 74 A, when the temperature of the fluid medium in the second fluid loop 17 becomes so low that it is in danger of freezing. For example, in an Open Loop configuration the controller 58 may receive a first sensor input 69 indicative of the fluid medium temperature within the second fluid loop 17 . When the first sensor input 69 reaches a predetermined level, the controller 58 activates the circulation pump 54 and a valve 74 A, to circulate water from the tank 112 - 1 through the second fluid loop 17 to prevent freezing therein. It is noted that if the refrigeration unit 22 is operational, then the circulating pump 54 will operate as discussed above to transfer heat from the refrigerant to the fluid medium at the heat exchanger 26 . [0034] In the event that the refrigeration unit 22 goes down during the winter months, the operation of the circulating pump 54 and a valve 74 A, to circulate fluid medium from the tank 112 - 1 through the second fluid loop 17 will help to prevent the fluid medium from freezing in the second fluid loop 17 . It is anticipated that other back-up sources of heat may be utilized with the system (such as gas or oil) to heat the tank 112 - 1 so that the tank 112 - 1 water will remain warm even during a long power outage. It is also anticipated that this anti-freezing operation of the controller 58 will be far less common, but will provide an important safety measure in the winter time to prevent the heat recovery unit 16 from freezing and increase its longevity. [0035] The controller 58 can be embodied by a variety of control circuitry, such as a programmed controller or dedicated hardware logic (PLD, FPGA, ASIC) and supporting circuitry (e.g., thermistors for temperature sensing or pressure transducers for pressure sensing), one or more relays and supporting circuitry (e.g., thermostats for temperature sensing or pressure controllers for pressure sensing) or other suitable circuitry. [0036] The operational control of the fan 36 of the refrigeration unit 16 is best understood with reference to FIGS. 1 , 2 and 4 . A fan control 30 is provided in the form of a delay relay or controller in electrical communication with the fan 36 . During normal operation of the refrigeration unit 16 , the fan control 30 delays the operation of the fan 36 until a condition within the refrigeration unit 16 reaches a predetermined level. As discussed above, the heat recovery unit 16 removes heat from the refrigerant in the flow path 19 a of the flow loop 19 of the refrigeration unit 22 that would otherwise need to be removed by the fan 36 . Thus, the fan 36 need not be operated until the heat recovery unit 16 can no longer remove enough heat from the refrigeration unit 22 to keep the refrigeration unit 16 operating in a desired manner. [0037] For example, in medium temperature refrigeration units such as those present in a restaurant, bar, or other commercial establishment, it is typically desired that the refrigerant exiting the condenser 34 be in a vapor condition with a desired temperature and/or pressure. The fan control 30 receives a fourth input 52 from the refrigeration unit 22 which is indicative of the temperature of refrigerant within the flow loop 19 of the refrigeration unit 16 . The fan control 30 maintains the fan 36 in an off condition until the fourth input 52 reaches a predetermined level, at which time, the fan control 30 activates the fan 36 to expel heat from the refrigerant to the ambient air 38 at the condenser 34 . [0038] In one preferred embodiment, the fourth input 52 is a pressure input from a pressure transducer 52 - 1 positioned in the flow loop 19 of the refrigeration unit 22 between the heat exchanger 26 and the condenser 34 . If the pressure of the refrigerant in the flow loop 19 exceeds a predetermined limit after passing through the heat exchanger 26 , then insufficient heat has been removed from the refrigerant by the heat exchanger 26 . Typically, this results from the water in the tank 112 - 1 being of a sufficiently high temperature from the heat already collected by the heat recovery unit 16 and/or the solar collection unit 18 (further discussed below). [0039] When the pressure of the refrigerant in the flow loop 19 exceeds a predetermined limit after passing through heat exchanger 26 , the fan control 30 activates the cooling fan 36 to expel waste heat from the refrigerant to the outside air 38 . Conversely, when the pressure of the refrigerant in the flow loop 19 is below the predetermined limit after passing through heat exchanger 26 , the fan control 30 maintains the cooling fan 36 in a normally deactivated state. In embodiments of the invention in which the refrigeration unit 22 is a medium temperature refrigeration unit, the predetermined pressure limit at transducer 52 - 1 could be approximately 200 pounds per square inch (PSI). [0040] The controller 30 can be embodied by a variety of control circuitry, such as a programmed controller or dedicated hardware logic (PLD, FPGA, ASIC) and supporting circuitry (e.g., thermistors for temperature sensing or pressure transducers for pressure sensing), one or more relays and supporting circuitry (e.g., thermostats for temperature sensing or pressure controllers for pressure sensing) or other suitable circuitry. An exemplary embodiment of controller 30 is shown in FIG. 4 , which includes a pressure control unit 701 in electrical connection between one leg 702 A of line AC and one of the terminals of the condenser fan 36 as shown. The other terminal of the condenser fan is connected to the other leg 702 B of line AC. A capillary tube 703 is in fluid communication with the fluid loop 19 , preferably at a point downstream of the heat recovery unit 26 and upstream of the condenser 34 (e.g., preferably at 52 - 1 as shown, but may optionally be placed anywhere along the length of the condenser) in order to sample the pressure of the refrigerant in the fluid loop 19 . The pressure control unit 701 measures the sampled pressure of the refrigerant of the fluid loop 19 and provides a normally-off current path between leg 702 A and the terminal of the condenser fan 36 that is turned on when the sampled pressure reaches a predetermined cut-in pressure. This current path is then returned to the normally-off state when the pressure falls below a predetermined cut-off pressure. In the preferred embodiment, the cut-in and cut-out pressures are set by user input (for example, by user adjustment of dials for setting such cut-in and cut-out pressures). In the preferred embodiment, the pressure control unit 701 is realized by a unit (e.g., the 016 Single Pressure Control unit) sold commercially by Ranco Controls of Delaware, Ohio. [0041] Thus, system 110 , through the operation of the fan control 30 of the refrigeration unit 22 , maximizes the amount of heat recovered by the heat recovery unit 16 by eliminating the expulsion of heat from the refrigerant to the ambient air when such expulsion not needed. Further, system 110 minimizes energy usage by leaving fan 36 in a normally “off” state until such time as the heat recovery unit 16 no longer has sufficient capacity to remove enough heat from the refrigerant in the flow loop 19 to keep the refrigeration unit 22 operating as desired. [0042] The system 110 of the present invention also preferably incorporates in one fluid medium loop of a hybrid water heating system, the solar water heater unit 18 , and uses it in conjunction with the heat recovery unit 16 . The solar water heater unit 18 and HRU 16 and its operational control is best understood with reference to FIG. 1 . [0043] The solar collection unit 18 provides heat captured from solar energy to the water in the tank 112 - 1 . Thus, the water in tank 112 - 1 is heated not only by the heat recovery unit 16 , but also by the solar collection unit 18 . The fan control 30 protects the refrigeration unit 22 from damage due to overheating and maintains the refrigeration unit 22 in a desired operating condition when a large amount of heat is added to the water in the tank 112 - 1 by both the heat recovery unit 16 and solar collection unit 18 thru one Solar and HRU fluid medium Loop. [0044] The solar collection unit 18 includes a circulating pump 54 and a valve 74 B, which circulates a heat transfer medium through a flow loop 17 . A solar collector 56 and a heat exchanger 60 A or B are operably coupled to the flow loop 17 as shown in FIG. 1 . A controller 58 is provided for selectively activating and deactivating the circulating pump 54 and a valve 74 B, of the solar collection unit 18 . When heat is available from solar energy the controller 58 is configured to activate the circulating pump 54 and a valve 74 B,to pump a heat-transfer fluid such as, but not limited to, propylene glycol through the solar collector 56 and the heat exchanger 60 A or B via the fluid loop 17 . The solar collector 56 thus heats the heat-transfer fluid, and the heat from the heat-transfer fluid is used to indirectly heat the water in the tank 112 - 1 via the heat exchanger 60 A or B. [0045] The fluid loop 17 of the solar collection unit 18 and HRU 16 is shown ( FIG. 1 ) by way of example as an indirect or closed-loop circulation system where the circulating pump 54 circulates the heat-transfer fluid through the solar collector 56 and HRU 16 in fluid communication with the heat exchanger 60 A or B to indirectly heat the water in the tank 112 - 1 . However, the solar collection unit 18 may also be a direct or open-loop circulation system in which the pump 54 circulates the potable water from the tank 112 - 1 directly through the solar collector 56 and HRU 16 back into the tank 112 - 1 . [0046] Conversely, while the fluid loop 17 of the heat recovery unit 16 is shown ( FIG. 1 ) by way of example as a indirect or closed-loop circulation system where the pump 54 circulates the fluid medium from the tank 112 - 1 through the heat exchanger 26 and back into the tank 112 - 1 , the fluid loop 17 may instead be an indirect or closed-loop circulation system isolated from the water in the tank 112 - 1 in which the pump 54 circulates a heat-transfer fluid through the heat exchanger 26 and through an additional heat exchanger 60 A or B in a heat exchange relationship with the water in tank 112 - 1 to indirectly heat the water in the tank. [0047] In addition, the heat exchanger 60 A or B disposed at the tank 112 - 1 is shown by way of example only as a flat heat exchanger in tank 112 - 1 . However, it is contemplated that the heat exchanger 60 may be any device sufficient to place the heat-transfer fluid of the solar collection unit 18 in a heat exchange relationship with the water in the tank 112 - 1 . The tank 112 - 1 may also be a jacketed tank in which the heat exchanger 60 forms a heat exchange jacket around the outer surface of the tank 112 - 1 . [0048] The solar collector 56 can be any device sufficient to collect heat from solar energy. For example, the solar collector 56 can be a glazed flat-plate collector, an un-glazed flat-plate collector, an evacuated-tube solar collector, a photo-voltaic module, a drain-back system, and any combinations thereof. [0049] The term “glazed flat-plate collectors” used herein refers to collectors having an insulated, weatherproofed box that contains a dark absorber plate under one or more glass or plastic covers. The term “unglazed fiat-plate collectors” used herein refers to collectors having a dark absorber plate, made of metal or polymer, without a cover or enclosure. The term “evacuated-tube solar collectors” used herein refers to collectors having parallel rows of transparent glass tubes where each tube contains a glass outer tube and a metal absorber tube attached to a fin. The fin's coating absorbs solar energy but inhibits radiative heat loss. The term “photo-voltaic module” used herein refers to collectors having an array of photo-voltaic cells that convert solar energy into electrical potential. The electrical potential can be used to provide current to an electrical heating element, which heats the water in the tank 12 . [0050] The controller 58 of the solar water heater unit 18 controls the circulating pump 54 and a valve 74 B, to circulate the heat-transfer fluid from the heat exchanger 60 in the tank 112 - 1 through the solar collector 56 only when heat is available at the solar collector 56 . For example, the controller 58 may receive an input 66 indicative of a condition of the solar collector 56 . The input 66 may include, but is not limited to, a temperature signal indicative of the temperature of the heat-transfer fluid at the solar collector 56 . When the input 66 reaches a predetermined limit indicating that sufficient heat is available from the solar collector 56 , the controller 58 activates the circulation pump 54 and a valve 74 B. [0051] The controller 58 is preferably configured to activate the circulating pump 54 and a valve 74 B, to cease circulating the heat-transfer fluid through the solar collector 56 and the heat exchanger 60 when the water within the tank 112 - 1 reaches a predetermined temperature. For example, the controller 58 can receive an input 68 indicative of a temperature of the water within the tank 112 - 1 . When the input 68 reaches a predetermined limit, the controller 58 deactivates the circulating pump 54 and a valve 74 B. The circulating pump 54 can be an electrically powered pump, powered by a standard 115-volt power source. The pump 54 may also be powered by electricity collected by a photo-voltaic solar collector (not shown). [0052] The controller 58 is described by way of example as operating based on a temperature limit (e.g., sensed from an input 66 ) and a temperature limit (e.g., sensed from an input 68 ). However, as discussed in FIG. 3 , the controller 58 may also operate as a differential controller in which the controller 58 activates the circulating pump 54 and a valve 74 B, when the inputs 66 , 68 are indicative of a temperature differential of at least a predetermined value. For example, the controller 58 can be configured to activate the circulating pump 54 and a valve 74 B, when the 66 , 68 are indicative of at least approximately 8 degrees Fahrenheit (F) and can deactivate the pump 54 and a valve 74 B, when the temperature differential is less than approximately 8 degrees Fahrenheit (F). Similarly, the controller 58 of the heat recovery unit 16 ( FIG. 1 ) may be configured to operate as a differential controller in which the controller 58 only activates the circulating pump 54 and a valve 74 A, when the inputs 69 / 68 are indicative of at least a predetermined value. The controller 58 can also operate to deactivate the circulating pump 54 and a valve 74 B, upon the input 66 exceeding a temperature limit indicative that the solar collector is at a maximum temperature for preventing damage to system components. A relief valve (not shown) is operably coupled to the flow loop 17 for lowering the pressure within the flow loop 17 in the event that the input 66 exceeds the temperature limit. In an open configuration of the relief valve, the second heat transferring medium is drained from the flow loop 17 in gas or liquid form to lower the pressure therein. [0053] The controller 58 can be embodied by a variety of control circuitry, such as a programmed controller or dedicated hardware logic (PLD, FPGA, ASIC) and supporting circuitry (e.g., thermistors for temperature sensing or pressure transducers for pressure sensing), one or more relays and supporting circuitry (e.g., thermostats for temperature sensing or pressure controllers for pressure sensing) or other suitable circuitry. In an exemplary embodiment, the controller 58 is realized by a programmed controller adapted for differential temperature control of solar energy systems, such as the Resol module. [0054] Preferably, only one common pump is needed to circulate the fluid through all of the heat recovery units and, preferably, the solar collector. The controller 58 is configured to send signals to direct the only one common pump to circulate the fluid, which becomes heated with, in effect, free heat available from the solar collection unit during daylight hours and from the at least one refrigeration unit during hours of operation of the at least one refrigeration unit so as to maintain a temperature in the common piping higher that would otherwise arise if there was just one of the solar collection unit and the refrigeration unit but not both. The higher temperature of the fluid allows the free heat to heat the fluid to a desired temperature quicker to meet demand than would otherwise be the case if the fluid temperature were at a lower temperature. [0055] The controller 58 may be configured to receive a heat demand signal indicative of a demand for heating the potable water and a heat demand satisfaction signal indicative of satisfying the demand. The controller is configured to send a command signal to the only one pump to circulate the fluid to satisfy the demand if the demand is not yet met based on receipt of the heat demand signal. The controller 58 is configured to send a command signal to the only one pump to cease the fluid circulation once the demand for heating the potable water has been met based on receipt of the heat demand satisfaction signal. [0056] Further piping may be provided between the tank and the solar collector unit to bypass the at least one heat exchanger to establish fluid communication directly between the tank and the solar collector unit via the further piping. [0057] When heat is unavailable from either the heat recovery unit 16 or the solar collection unit 18 , the system 110 utilizes a conventional heating element 120 to heat the water in the tank 112 - 2 . Heating element 120 may be an electrically powered element, a gas-burning element, an oil-burning element, and combinations thereof. [0058] The hybrid hot water heat system 110 of the present invention thus combines three heating sources, two of which are available without consuming additional energy. Additionally, the fan control 30 of the hybrid hot water heat system 110 of the present invention selectively activates and deactivates the fan 36 of the vapor compression refrigeration unit 22 to minimize the available heat expelled to the ambient air 38 . The fan control 30 also maximizes the amount of heat recovered by the heat recovery unit 16 and minimizes the amount of energy used while protecting the vapor compression refrigeration unit 22 from being damaged. [0059] The bypass system 180 allows a user to divert incoming water from the water source 14 to bypass the pre-heating tank 112 - 1 to flow directly into the heating tank 112 - 2 . In the illustrated embodiment of FIG. 1 , the bypass system 180 includes a first valve 182 , a second valve 184 , and a third valve 186 , each being a two-way valve having an open state and a closed state. When an operator desires the use of the pre-heating tank 112 - 1 , the first and second valves 182 , 184 can be moved to the open state while the third valve 186 is moved to the closed state. In this configuration, water from the water source 14 flows through the first valve 182 into the pre-heat tank 112 - 1 and from the pre-heat tank 112 - 1 to the heating tank 112 - 2 through the second valve 184 . [0060] Conversely, when an operator desires to bypass pre-heating tank 112 - 1 , the first and second valves 182 , 184 can be moved to the closed state while the third valve 186 is moved to the open state. In this configuration, water from the water source 14 flows through the third valve 186 directly into the heating tank 112 - 2 without passing through pre-heating tank 112 - 1 . [0061] The bypass system 180 is described above by way of example as a manually activated system in which the operator moves the valves 182 , 184 , 186 between the open and closed states. However, it is contemplated that the valves of bypass system 180 may be automatically controlled between the open and closed states based on the availability of heat from either the heat recovery unit 16 or the solar collection unit 18 . [0062] Additionally, the bypass system 180 is described above by way of example with respect to the three separate two-way valves 182 , 184 , and 186 . However, it is contemplated that the bypass system 180 may include any combination of valves sufficient to selectively place the pre-heating tank 112 - 1 in fluid communication with the water source 14 and the heating tank 112 - 2 . For example, it is contemplated that the bypass system 180 may include one three-way valve that replaces the first and third valves 182 , 186 . [0063] It should also be noted that the terms “first”, “second”, “third”, “upper”, “lower”, and the like may be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated. [0064] While the present disclosure has been described with reference to one or more exemplary embodiments, it is not intended that the invention be limited thereto, and it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated, but that the disclosure will include all embodiments.	A hybrid heating apparatus heats potable water with waste heat from heat recovery units and insolation from solar collectors. A single circulation pump circulates fluid between at least one heat exchanger and each of the heat recovery units and preferably the solar collector. A single controller receives sensor readings from the heat recovery units and the solar collector units and receives a demand to heat the potable water. To satisfy the demand, the controller determines the extent to which the demand may be satisfied from heat available from the heat recovery units and the solar collector units and sends command signals both to the circulating pump to circulate the fluid and to appropriate ones of valves at connections to those heat recovery units and solar collector units to allow fluid to circulate to be heated to flow to the heat exchanger for effecting heat exchange to heat the potable water.	5
FIELD OF THE INVENTION The present invention relates to an internal combustion engine, and specifically to a device for generating and controlling a flow of swirling air into the cylinders of an internal combustion engine to thereby promote combustion stability especially during periods of low torque output (i.e., light load operation). BACKGROUND OF THE INVENTION Much work is presently being done to produce air swirl in combustion chambers of an internal combustion engine. Air swirl is desirable in combustion engines because it promotes combustion stability, i.e., providing limited cycle to cycle variations of the air/fuel mixture and the air velocity profile in the cylinder, especially in the region of the cylinder proximate to the spark plug. As a result, the cylinders operate under similar firing conditions during each firing cycle especially at light load, or low torque output. This combustion stability allows a reduction in the lean operating limit of the internal combustion engine. Prior to the present invention, efforts to produce air swirl have focused on redesigning the contour of the intake valve port opening into the combustion chamber by bringing the intake port closer to the engine block and forming a corkscrew shaped air intake path to the combustion chamber. Such efforts have proved disadvantageous because the opening of the intake valve port is fixed limiting the volume of air into the combustion chamber. As a result, the volume of air entering the combustion chamber during high RPM operation is less than that required to achieve maximum power output. This effect is known as reduced volumetric efficiency. It is therefore a primary object of the present invention to provide a device for attaining high level combustion stability by producing a consistent air/fuel ratio and air swirl velocity profile in the cylinder, especially in the vicinity of the firing region of the spark plug, and especially under light load conditions by directing an air swirl int the combustion chamber of an internal combustion engine It is a further object of the present invention to provide means for obtaining increased peak power output during high RPM operating conditions without increasing engine displacement by increasing volumetric efficiency and thereby generating the desired air flow into the cylinders during both light and heavy load conditions. It is another object of the present invention to facilitate air-fuel preparation by providing a high speed swirl of air in the path of the fuel supplied by the fuel injector thereby placing fewer design constraints upon the fuel injector. SUMMARY OF THE INVENTION The foregoing objects and other objects inherent from the following disclosure are accomplished by the present invention and method for use thereof. The invention in its broadest aspect comprises a means for generating a swirling flow of air, in an air/fuel mixture, especially during light load operation, in the combustion chamber of an internal combustion engine having at least one intake valve for transmitting air into the combustion chamber, said means comprising a nozzle having at least one opening for receiving air and at least one expulsion opening for directing air into the combustion chamber with a pathway connecting said air receiving openings and expulsion openings, and means for controlling the flow of air through said pathway. The nozzle described herein is positioned in a valve pocket which is located above the intake valve of the combustion chamber. The nozzle is positioned within the valve pocket such that the expulsion opening is at an acute angle with respect to the plane of the intake valve head. A high speed flow of air is generated through the pathway of the nozzle and is directed out the expulsion opening at said angle across the opening of the intake valve. This high speed air, which is mixed with fuel in the valve pocket, enters the combustion chamber creating the desired air swirl. The means for controlling the air flow through the pathway of the nozzle comprises an electric solenoid which is movable from a fully opened position allowing maximum air flow to a closed position prohibiting the flow of air. The size of the opening of the pathway resulting from the movement of the solenoid is controlled by a computer which is programmed to determine the amount of air necessary for operation during existing load conditions based on torque demand (e.g., gas pedal position), tachometer reading and other factors commonly input into engine computers and known in the art to promote efficient combustion. Variation in power output during light load operation is achieved by variation in the size and duration of the pathway opening. The computer controlled solenoid allows timed air flow through the pathway of air nozzle during the intake stroke of the engine. Positioning of the air nozzle at an angle with respect to the intake valve opening generates a high speed flow of air into the combustion chamber past the intake valve. The air swirl created by the gas motion during the intake stroke provides a consistent air/fuel mixture and swirl velocity profile within the cylinder, especially in vicinity of the spark plug, which maintains substantially similar conditions from cycle to cycle firing. Air from the atmosphere is driven into and through the nozzle by the pressure differential between the pressure of ambient air entering the nozzle from the atmosphere and the pressure within the valve pocket connected to the intake manifold. The speed at which the air moves through the air nozzle and into the combustion chamber can be made to reach sonic velocity due to the above-described pressure differential and by controlling the duration and size of the pathway in the air nozzle by regulating the position of the solenoid. Air movement at sonic speeds also aids in atomizing the fuel which enters the cylinder from the fuel injector with the air especially when the fuel injector releases fuel into the path of the sonic air stream in the valve pocket. During heavy load operation a customarily employed throttle plate opens the intake manifold to the atmosphere thereby providing sufficient air to the combustion chamber. Accordingly, the air nozzle may be largely bypassed as the main source of air flow into the combustion chamber by closing or reducing the size of air pathway by operation of the solenoid. Thus, the intake port, valve pocket and valve can be designed for high power output conditions (e.g., for high volumeric efficiency to enable a higher volume of air flow and increased power during high RPM conditions) without sacrificing efficiency during light load conditions. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an air nozzle in accordance with the invention. FIG. 2a is a cross-sectional view of the air nozzle and solenoid through line 1--1 of FIG. 1 showing the solenoid in the open position for maximum air flow. FIG. 2b is a cross-sectional view of the air nozzle and solenoid through line 1--1 of FIG. 1 with the solenoid in the closed position for prohibiting air flow. FIG. 3 is a plan view of the invention mounted in an internal combustion engine. DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings and specifically to FIG. 1, the means for creating an air swirl in the combustion chamber 30 of an internal combustion engine includes an air nozzle 2 having a body 4 having therein in at least one air receiving opening 8. The nozzle 2 also has a forward section 10 having at one end thereof at least one expulsion opening 12. As shown in FIGS. 2a and 2b, the air receiving openings 8 open into continguous pathways 14 which are connected to a common pathway 16 by contoured sides 18. The common pathway 16 terminate at an expulsion opening 12. At least a portion of the forward section 10 of the nozzle 2 is within the valve pocket 24 lying above the intake valve seat 28 as shown in FIG. 3 and described hereinafter. The body 4 of the nozzle 2 including the air receiving openings 8 protrudes through the cylinder head and lies exterior thereto so as to draw air from the atmosphere. As shown in FIG. 2a, the size of the junction 19 connecting pathways 14 and the common pathway 16 is controlled by a solenoid 6 which comprises a stopper 20 having contoured sides 22 and opposing contoured sides 18 defining the junction 19 of the pathways 14 and the common pathway 16. The stopper 20 is movable from an open position as shown in FIG. 2a to a closed position as shown in FIG. 2b. Movement of the stopper 20 is controlled by a standard computer 38, which is programmed to respond to accelerator pedal position to adjust the air volume requirements needed within the combustion chamber 30 to reduce the lean operating limit and obtain optimum combustion stability. In operation under light load conditions, the primary source of air into the combustion chamber 30 is through the nozzle 2. Specifically, air, being filtered as commonly known in the art, enters from the atmosphere into the air receiving openings 8 and passes through the pathways 14. The air is caused to flow into the common pathway 16 by the contour of the sides 18 at the junction 19 of the pathways 14 and common pathway 16. The air proceeds through the common pathway 16 where it exits at expulsion opening 12. Referring to FIG. 2b, during heavy load operation where the primary source of air into the combustion chamber 30 is from the intake manifold and not the nozzle 2 of the present invention, the stopper 20 is moved to the closed position. In this position, the sides 22 of the stopper 20 are in sealed relationship with the sides 18 at the junction 19 thereby preventing the flow of air from the pathways 14 into the common pathway 16. As a result, there is little, if any, air exiting the expulsion opening 12. Of course, the stopper 20 may be moved to any partially depressed position (i.e., between the open position shown in FIG. 2a and the closed position in FIG. 2b) to thereby monitor the flow of air into the combustion chamber 30. This enables the nozzle 2 to provide air swirl into the combustion chamber 30 in varying amounts depending on the parameters monitored by the computer 38. Referring to FIG. 3, the nozzle 2 is positioned approximately perpendicular to a radial line crossing the cylinder bore, at an acute angle to the plane of the top of the cylinder. At least a portion of the forward section 10 of the nozzle 2 including the expulsion opening 12 are positioned within a valve pocket 24 leading to the upper portion of the combustion chamber 30. At the top of the combustion chamber 30 are intake valve seats 28 which provide an opening into the combustion chamber 30 from the valve pocket 24. When the valve 26 rises during the intake stroke of the engine, the intake valve seats 28 permit air from the valve pocket 24 provided by the nozzle 2 or the intake mainfold to enter into the combustion chamber 30. The air entering the valve pocket 24 is mixed with fuel exiting the discharge port of the fuel injector 34 in the valve pocket 24. In operation under light load conditions the computer 38 signals the stopper 20 to rise so that air enters the air receiving openings 8 of the nozzle 2, flows through pathways 14 and the common pathway 16 and exits the expulsion opening 12 into the valve pocket 24 where the air is mixed with the fuel entering the valve pocket 24 from the fuel injector 34. At the same time, the valve 26 rises to permit the air/fuel mixture to enter the combustion chamber 30 past the intake valve seats 28. The expulsion opening 12 of the nozzle 2 is positioned in the valve pocket 24 at an acute angle with respect to the plane of the top of the cylinder. As a result, the air from expulsion opening 12 combines with the fuel from fuel injector 34 to create a high speed air/fuel flow which produces a swirl within the combustion chamber 30. Once the air/fuel swirl enters the combustion chamber 30, the piston 32 rises compressing the mixture for ignition. Upon ignition the piston 32 is forced downward ready for the next cycle. In heavy load operations requiring peak output, the stopper 20 is depressed preventing or substantially preventing the flow of air through the nozzle 2. The air needed for ignition in the combustion chamber 30 is supplied primarily from the intake manifold through the valve pocket 24. It should be understood that the invention described in the drawings is capable of modification apparent to those skilled in the art. For example, the number of air receiving openings 8 and expulsion openings 12 may vary. The solenoid 6 may be of the fast acting electromagnetic type. The computer 38 may be programmed to control the size of the junction 19 within the nozzle based on torque demand, position of the gas pedal, engine RPM's, climatic conditions, etc. It is preferred that the stopper 20 be controlled in a manner in which the pressure at the air receiving openings 8 is about twice the pressure of the air exiting expulsion openings 12, representing a pressure ratio of 2:1 across the nozzle 2 during light load operation.	An air inlet nozzle is mounted in a valve pocket above the intake valve of a combustion chamber to allow high speed airflow to mix with fuel in the pocket and enter the combustion chamber to create desired air swirl. Airflow through the nozzle is varied by a computer operated solenoid.	5
REFERENCE TO RELATED APPLICATION The present application is a continuation of U.S. Application Ser. No. 09/161,156, filed Sep. 25, 1998, now U.S. Pat. No. 6,197,634 which is a division of U.S. application Ser. No. 08/943,222, filed Oct. 6, 1997, now U.S. Pat. No. 6,015,986 which is a file wrapper continuation of U.S. application Ser. No. 08/576,952, filed Dec. 22, 1995 now abandoned. FIELD OF THE INVENTION The invention relates generally to thin film integrated circuit design and fabrication. In particular, the invention pertains to electrode design and materials used in stacked cell capacitor Dynamic Random Access Memories (DRAM). BACKGROUND OF THE INVENTION A dynamic random access memory (DRAM) cell typically comprises a charge storage capacitor (or cell capacitor) coupled to an access device such as a Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET). The MOSFET functions to apply or remove charge on the capacitor, thus affecting a logical state defined by the stored charge. The amount of charge stored on the capacitor is determined by the capacitance, C=∈A/d, where ∈ is the dielectric constant of the capacitor dielectric, A is the electrode (or storage node) area and d is the interelectrode spacing. The conditions of DRAM operation such as operating voltage, leakage rate and refresh rate, will in general mandate that a certain minimum charge be stored by the capacitor. In the continuing trend to higher memory capacity, the packing density of storage cells must increase, yet each will maintain required capacitance levels. This is a crucial demand of DRAM fabrication technologies if future generations of expanded memory array devices are to be successfully manufactured. Nevertheless, in the trend to higher memory capacity, the packing density of cell capacitors has increased at the expense of available cell area. For example, the area allowed for a single cell in a 64-Mbit DRAM is only about 1.4 μm 2 . In such limited areas, it is difficult to provide sufficient capacitance using conventional stacked capacitor structures. Yet, design and operational parameters determine the minimum charge required for reliable operation of the memory cell despite decreasing cell area. Several techniques have been developed to increase the total charge capacity of the cell capacitor without significantly affecting the cell area. These include new structures utilizing trench and stacked capacitors, electrodes having textured surface morphology and new capacitor dielectric materials having higher dielectric constants. Recently, for example, a great deal of attention has been given to the development of thin film dielectric materials that possess a dielectric constant significantly greater (>10×) than the conventional dielectrics used today, such as silicon oxides or nitrides. Particular attention has been paid to Barium Strontium Titanate (BST), Barium Titanate (BT), Lead Zirconate Titanate (PZT), Tantalum Pentoxide (Ta 2 O 5 ) and other high dielectric constant materials as a cell dielectric material of choice for DRAMs. These materials, in particular BST, have a high dielectric constant (>300) and low leakage currents which makes them very attractive for high density memory devices. Due to their reactivity and complex processing, these dielectric materials are generally not compatible with the usual polysilicon electrodes. Thus, much effort has been directed to developing suitable metal electrodes for use with such dielectric materials. As DRAM density has increased (1 MEG and beyond), thin film capacitors, such as stacked capacitors (STC), trenched capacitors, or combinations thereof, have evolved in attempts to meet minimum space requirements. Many of these designs have become elaborate and difficult to fabricate consistently as well as efficiently. Furthermore, the recent generations of DRAMs (4 MEG, 16 MEG for example) have pushed conventional thin film capacitor technology to the limit of processing capability. In giga-scale STC DRAMs the electrode conductivity plays an important role in device size and performance; thus, two kinds of capacitors have been considered, the three-dimensional metal electrode such as the FIN or CROWN, or the simple metal electrode with higher-permitivity dielectric films. For example, a recent article by T. Kaga et al. (“0.29 μm 2 MIM-CROWN Cell and Process Technologies for 1-Gigabit DRAMs,” T. Kaga et al., IEDM '94, pp. 927–929.) discloses a substituted tungsten process for forming three-dimensional metal electrodes from polysilicon “molds.” The article, herein incorporated by reference, discloses a method advantageous for creating metal structures, such as capacitor electrodes; nevertheless the simple structures created thus far are not sufficient to meet the demands of gigascale DRAM arrays. SUMMARY OF THE INVENTION It is an object of the present invention to provide a metal structure having a textured surface morphology. It is another object of the present invention to provide processes by which textured metal structures are fabricated, such processes being compatible with silicon integration technology. It is furthermore an object of the present invention to provide a metal-insulator-metal DRAM capacitor having textured electrodes advantageous for gigabit-scale memory arrays. In accordance with one aspect of the present invention a method of forming a textured metal structure comprises first forming a predetermined textured silicon structure having the desired form, and then replacing silicon atoms in the textured structure with metal atoms. A method of forming a predetermined textured structure preferably comprises depositing an amorphous or polycrystalline silicon structure by chemical vapor deposition, and then exposing the structure to a controlled annealing process to form a silicon surface having a textured surface morphology. The metal substitution process preferably comprises exposing the textured structure to a refractory metal-halide complex, and most preferably to WF 6 . In accordance with another aspect of the present invention, a process for fabricating a metal-insulator-metal capacitor on a semiconductor wafer comprises first forming a silicon electrode structure on the semiconductor wafer, texturizing the silicon electrode structure, and then replacing the silicon in the silicon electrode structure with a metal, thereby forming a textured metal electrode. The process further comprises depositing a dielectric layer having a high dielectric constant over the textured metal electrode followed by a metal layer deposited over the dielectric layer. Replacing the silicon in the silicon electrode structure preferably comprises exposing the silicon electrode structure to a refractory metal-halide complex, such as WF 6 . The dielectric layer preferably comprises a material selected from the group consisting of Ta 2 O 5 , BaTiO 3 , SrTiO 3 , Ba x Sr 1-x TiO 3 , and PbZr x Ti 1-x O 3 , and the metal layer preferably comprises titanium. In accordance with yet another aspect of the present invention a DRAM capacitor comprises a metal electrode having a textured surface morphology overlayed by a dielectric material having a high dielectric constant and covered by a metal layer. The metal electrode of the DRAM capacitor is preferably comprised of a refractory metal, such as tungsten. The dielectric material of the DRAM capacitor is preferably comprised of a material selected from the group consisting of Ta 2 O 5 , BaTiO 3 , SrTiO 3 , Ba x Sr 1-x TiO 3 , and PbZr x Ti 1-x O 3 . Furthermore, the top electrode layer of the DRAM capacitor preferably comprises a refractory metal, such as titanium. These and other objects and attributes of the present invention will become more fully apparent with the following detailed description and accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic section of an exemplary DRAM structure having textured electrodes. FIG. 2 is a schematic section of the DRAM structure shown in FIG. 1 illustrating a completed oxide “mold.” FIG. 3 is a schematic section of a preferred DRAM electrode after a metal substitution process. FIG. 4 is a schematic section of a preferred DRAM electrode after oxide removal. FIG. 5 is a schematic section of a preferred DRAM electrode with a deposited dielectric layer. FIG. 6 is a schematic section of a completed DRAM structure in accordance with the present invention. FIG. 7 is a schematic section of an alternative embodiment of a completed DRAM structure in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION In accordance with the principles of the present invention, complex metal structures having enhanced surface area advantageous for DRAM storage capacitors are fabricated by first forming rugged or texturized polysilicon (“poly”) electrodes and subsequently subjecting the poly structures to a metal-substitution process. The rugged metal electrodes are advantageous for high-density DRAM storage applications because they exhibit a substantially higher conductivity than conventional doped poly electrodes and they are compatible with high-∈ dielectric materials such as Ta 2 O 5 , BST, PZT and others. The preferred embodiment of the present invention is directed to a novel DRAM storage cell having a rugged metal electrode. The inventive aspects are herein disclosed in connection with a preferred process for fabricating rugged metal electrodes in accordance with the aforementioned principles, beginning with the formation of the cell capacitor itself. Referring to FIG. 1 , a conventional front-end DRAM cell formation comprises a semiconductor substrate 12 processed to a point where capacitor fabrication begins. At this stage in the fabrication process, the DRAM cell may have field oxide regions 16 , active regions 14 , word lines 18 , bit lines 20 , capacitor plugs 22 , and planarizing layer 23 . The capacitor structures of the present invention begins with the formation of polysilicon electrodes 24 having a textured or rugged surface region 26 . The textured surface 26 increases the electrode surface area without increasing the lateral dimensions of the electrode 24 . Polysilicon or amorphous silicon (a-Si) are preferred materials from which to fabricate the electrode structure 24 and rugged surface 26 . The subsequent metal substitution reaction (to be described) is shown to be effective in faithfully replicating the silicon structure by the substituted metal. Moreover, such reactions are compatable with other silicon fabrication processes and thus are capable of producing complex structures with high dimensional tolerances in a cost-effective manner. For example, the silicon electrodes 24 may be formed by depositing a layer of polysilicon or a-Si over the poly plugs 22 and adjacent oxide spacers 28 by well-known chemical vapor deposition processes. A subsequent planarizing process such as a chemical-mechanical polish or anisotropic etch may remove the topmost portion of the layer, yielding the isolated electrode structures 24 . The rugged surface 26 may be fabricated by a seeding and anneal process which produces a rough surface morphology comprising relatively large polycrystalline silicon grains of about 50–200 nm. Such processes for example are disclosed in U.S. Pat. No. 5,102,832 by M. E. Tuttle, herein incorporated by reference. A seeding process may for example comprise dispersing a material such as polysilicon or silicon dioxide over the surface which produces nucleation sites on the surface of the silicon electrodes 24 . A controlled anneal process then induces accumulation of silicon at the nucleation sites, thereby forming a rough surface morphology having enhanced surface area. The resulting surface morphology, often appearing bulbous, is usually comprised of relatively large polycrystallites, referred to as Hemispherically Grained Silicon (HSG). An exemplary method for forming HSG on complex stacked capacitor structures is disclosed in U.S. Pat. No. 5,340,765 by C. H. Dennison et al., also herein incorporated by reference. It will be appreciated that the processes heretofore disclosed are sufficient to produce a starting electrode structure 24 having a rugged surface 26 in accordance with the present invention. However, the processes themselves are disclosed by way of example, and it will also be appreciated that other processes may be utilized to achieve a similar result. Beginning with the complex electrode structure shown in FIG. 1 , and referring now to FIG. 2 , a next step in accordance with the present embodiment comprises depositing a silicon dioxide (“oxide”) layer over the entire structure and planarizing to produce the filled oxide regions 30 . The oxide layer 28 and filled oxide regions 30 thus form a boundary or “mold” between which the metal substitution process shall proceed. The next step in the present embodiment is to convert the silicon electrode structure 24 with ruggedized surface 26 to a metal electrode by the general process: aM x R y +b Si →axM+b Si R ay/b where M x R y is a refractory metal-halide complex such as WF 6 , and a, b are appropriate numerical constants. It is anticipated that a variety of refractory metal complexes may be used for the substitution, such as complexes of tungsten, molybdenum, and titanium. For example, the silicon comprising the electrode structures 10 , may be converted to tungsten (W) by the process: 2WF 6 +3Si - - - >2W+3SiF 4 yielding electrodes 32 having rugged surfaces 26 comprised of substantially tungsten metal, as shown in FIG. 3 . The process may be carried out in situ by exposing the wafer to the volatile W complex. The time required for a substitution will in general depend upon other parameters such as the wafer temperature, W-complex partial pressure and volume of material to be substituted. For the general size of structures considered here, the metal substitution may require 10 or several tens of minutes. The process may be accelerated by a chemical-oxide pretreatment, for example comprising exposing the silicon electrode structures 10 to a mixture of ammonia (NH 3 ) and hydrogen peroxide (H 2 O 2 ) prior to the metal substitution process. The chemical oxide is shown to assist in the substitution process. In general, as shown in FIG. 3 , the metal substitution results in a conversion of the electrode structures 10 into structures comprising substantially of the substituted metal. In the present embodiment, the structures 10 are comprised of substantially W. As shown in FIG. 4 , the oxide regions 28 and 30 are removed by wet etching to expose the metal electrode structures to further processing. An appropriate dielectric layer 34 is then deposited conformally over the metal electrode structures 10 as shown in FIG. 5 . Preferred dielectric layers comprise materials having high dielectric constant ∈, such as Ta 2 O 5 , BaTiO 3 , SrTiO 3 , Ba x Sr 1-x TiO 3 or PbZr x Ti 1-x O 3 . Such materials may be deposited by chemical vapor deposition processes, as is well-known in the art. The capacitor structure is completed by deposition of a reference electrode layer 36 , preferably also by a CVD process. The reference electrode 36 should minimally comprise a material having high conductivity, and which is also chemically compatible with the dielectric layer 34 . CVD titanium or TiN may for example serve as reference electrodes as they are compatible with titanate-based dielectrics. As shown in FIG. 7 , alternative embodiments of the complex, rugged metal electrodes may comprise textured surfaces 26 extending over the outer portions of the metal electrodes 38 , thereby providing even greater capacitance. Clearly the principle of forming rugged metal electrodes may be extended to a variety of capacitor arrangements where good conductivity and high capacitance are requisite in small geometries. Although described above with reference to the preferred embodiments, modifications within the scope of the invention may be apparent to those skilled in the art, all such modifications are intended to be within the scope of the appended claims.	Thin film metal-insulator-metal capacitors having enhanced surface area are formed by a substituting metal for silicon in a preformed electrode geometry. The resulting metal structures are advantageous for high-density DRAM applications since they have good conductivity, enhanced surface area and are compatible with capacitor dielectric materials having high dielectric constant.	8
TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for use in a Machine-to-Machine communication system. BACKGROUND [0002] The term M2M (Machine-to-Machine) generally refers to data communications between machines in the form of telemetry or telematics. M2M communication can take place over Ethernet, Public Switched Telephone networks (PSTN) or the Internet but in recent years an increasing proportion of M2M communication now takes place over public wireless data networks such as the General Packet Radio Service (GPRS). [0003] In the M2M world most communication is message based and is therefore suitable for going through a proxy. FIG. 1 of the accompanying drawings illustrates schematically a known M2M system comprised of a Broker 1 , one or several Applications 2 , and one or more Sensor Networks (SN) 3 . Each SN 3 comprises at least one data collecting device (not shown) and communicates with the Broker 1 via an SN Gateway 4 . The Broker 1 collects data from all SNs 3 and provides data services to the Applications 2 , performing data processing and aggregation services so that the Applications 2 can be provided with processed data from any of a number of SNs 3 . The Broker 1 also provides data access authorization and a data market place for individual sensor network providers. In such a system, the SN Gateway 4 of each individual SN 3 can be a very simple device, only authenticating and communicating with the Broker 1 . [0004] With the rapid deployment of SNs and increased usage of M2M communication, the data processing workload of a Broker can be significant, especially when streaming data is sent from a SN. It is desirable to address this issue. SUMMARY [0005] According to a first aspect of the present invention there is provided a method of at least partly delegating processing of data in a machine-to-machine system to reduce computational load on a broker entity while maintaining security of the data to be processed, the broker entity serving as a link between a node of a sensor network providing the data and an application node requesting the data. In the method, at the broker entity, following receipt of a request for processed data from the application node, the node to provide the data to be processed is determined, a data key for the data-providing node is generated, a data-processing algorithm for processing the data in dependence upon the request is generated, the data key is sent to the data-providing node, and the data key and data-processing algorithm are sent to a remote data-processing entity. At the data-providing node, the data is encrypted using the data key and sent to the data-processing entity. At the data-processing entity, the data is decrypted using the data key, processed using the data-processing algorithm and the processed data is sent to the application node. [0006] Embodiments of the present invention provide for distribution of data processing to increase scalability of M2M systems whilst maintaining the privacy of the information provided by sensor network. [0007] Embodiments of the present invention provide that the data-processing entity is authenticated by sending a message from the broker entity to the data-processing entity, for example via the application node, requesting the data-processing entity's public key certificate. The data-processing entity sends a message to the broker, for example via the application node, containing the data-processing entity's public key certificate and the broker entity confirms if the certificate is valid. [0008] In a particular implementation, the step of sending the data key and data-processing algorithm to the data-processing entity comprises, at the broker entity, encrypting the data key and data-processing algorithm using a public key of the data-processing entity, sending the encrypted data key and data-processing algorithm to the data-processing entity. At the data-processing entity, the data key and data-processing algorithm are decrypted using the data-processing entities private key. [0009] It may be that the data-processing algorithm is arranged so as to filter out at least some information from the data it is used to process and that only the processed data is sent to the application node, thereby hiding the unprocessed data from the application node. [0010] The data key and data-processing algorithm may be sent to the data-processing entity via the application node. [0011] The sending of data from the data-providing node to the data-processing entity may bypass the broker entity. The data-providing node may comprise a plurality of nodes. [0012] The method may further comprise sending a further data-processing algorithm to the data-processing entity, and using this data-processing algorithm at the data-processing entity to process already-received data. At the data-processing entity, the data processed using the further data-processing algorithm may be sent to a further application node associated with the further data-processing algorithm. [0013] In a particular implementation, the step of sending the data to the data-processing entity comprises, establishing a communication network session between the data-providing node and the data-processing entity, and sending the data using the communication network session. [0014] Establishing the communication network session may comprise, at the broker entity, generating an access token and a session key and sending these to the data-providing node, the data-providing node using the access token and the session key to authenticate and register with the communication network, and once the data-providing node is registered with the communication network, the data-providing node sending a session initiation message to the data-processing entity. The session key may be a cryptographic function of the broker's public key and a session identifier, and the access token may comprise at least the identity of the broker and the session identifier signed with a private key of the broker. [0015] Authenticating and registering the data-providing node with the communication network may comprise, sending a register message containing the access token to the communication network, the communication network using the identity of the broker contained within the access token to determine the public key of the broker, using the session identifier contained within the access token and the public key of the broker to calculate the session key, and using the session key as a shared secret to mutually authenticate the communication network and the data-providing node. [0016] The communication network may be an IP Multimedia Subsystem. [0017] The data-processing entity may be provided in an application environment associated with the application node. [0018] According to a second aspect of the present invention there is provided a broker entity. The broker entity comprising a receiver for receiving the request for processed data from the application node, a data reasoner for determining the node to provide the data to be processed and generating the data-processing algorithm to process the data in dependence upon the request, a key generator for generating the data key for the data-providing node, a transmitter for sending the data key to the data-providing node, and a transmitter for sending the data key and data-processing algorithm to the remote data-processing entity. [0019] The broker entity may further comprise a transmitter for sending a message to the data-processing entity requesting the data-processing entity's public key certificate, a receiver for receiving a message containing the data-processing entity's public key certificate, and a processor for confirming if the certificate is valid and authenticating the data-processing entity. [0020] According to a third aspect of the present invention there is provided a data-providing node. The data-providing node comprising a receiver for receiving the data key, an encryptor for encrypting the requested data using the data key, and a transmitter for sending the encrypted data to the data-processing entity. [0021] The data-providing node may further comprise means for establishing a communication network session with the data-processing entity and a transmitter for sending the data using the communication network session. [0022] According to a fourth aspect of the present invention there is provided a data-processing entity. The data-processing entity comprising a receiver for receiving the data key and the data-processing algorithm from the broker entity, a receiver for receiving the encrypted data from the data-providing node, a decryptor for decrypting the data using the data key, a processor for processing the data using the data-processing algorithm, and a transmitter for sending the processed data to the application node. [0023] The data-processing entity may further comprise a receiver for receiving a message requesting its public key certificate and a transmitter for sending a message containing the public key certificate. [0024] According to a fifth aspect of the present invention there is provided a method of establishing a communication network session between first and second client terminals using a subscription of an interlinking node. In the method, at the interlinking node, generating an access token and a session key and sending these to the first client terminal, the first client terminal using the access token and the session key for authenticating and registering with the communication network and, once the first client terminal is registered with the communication network, sending a session initiation message to the second client terminal over the communication network to initiate establishment of the session. [0025] The session key may be a cryptographic function of the interlinking node's public key and a session identifier, and the access token may comprise at least the identity of the interlinking node and the session identifier signed with a private key of the interlinking node. [0026] In a particular implementation, the step of authenticating and registering the first client terminal with the communication network comprises sending a register message containing the access token to the communication network, the communication network using the identity of the interlinking node contained within the access token to determine the public key of the interlinking node, using the session identifier contained within the access token and the public key of the interlinking node to calculate the session key, and using the session key as a shared secret to mutually authenticate the communication network and the first client terminal. [0027] The communication network may be an IP Multimedia Subsystem. [0028] According to a further aspect of the present invention there is provided a method of providing data from a sensor network to an application in an application environment, comprising arranging for a data-processing algorithm to be provided to a trusted data processor in the application environment, and for the data to be provided from the sensor network to the trusted data processor for processing by the trusted data processor using the data-processing algorithm, with the processed data being forwarded to the application. It may be that only the processed data is forwarded to the application. The data may be provided securely from the sensor network to the trusted data processor. [0029] The data provided from the sensor network to the trusted data processor may bypass a broker entity arranged between the sensor network and the application for providing data services to the application. Further data-processing algorithms may be provided to the trusted data processor for processing existing data previously provided from the sensor network to the trusted data processor, this processed data being forwarding to the same or a different application. [0030] An embodiment of the present invention provides at least one of the following advantages: Distributes the workload to increase scalability of the M2M system Protects the privacy of the information provided by the SNs That the Broker may control the traffic from the SNs to the Application That the SN Gateway may use the IMS network without an ISIM or an IMS subscription. BRIEF DESCRIPTION OF THE DRAWINGS [0035] FIG. 1 , discussed hereinbefore, illustrates schematically a known M2M System; [0036] FIG. 2 illustrates schematically a M2M System according to an embodiment of the present invention; [0037] FIG. 3 illustrates schematically a Trusted Data Processor according to an embodiment of the present invention; [0038] FIG. 4 illustrates an example signalling flow of a secure task delegation process according to an embodiment of the present invention; and [0039] FIG. 5 illustrates an example signalling flow of an IMS Registration and session establishment for a secure task delegation process according to an embodiment of the present invention. DETAILED DESCRIPTION [0040] As mentioned above, with the rapid deployment of SNs and increased usage of M2M communication, the data processing workload of a Broker can be significant, especially when streaming data is sent from a SN. It is therefore desirable that the Broker can delegate some of its data processing tasks to Applications in order to maintain scalability of the system. Delegating tasks to Applications in order to reduce the workload on the Brokers requires that the SNs send data directly to those Applications. In addition, when the data being sent from a SN to an Application is in a streamed format and no further processing is required, it would be better if the gateway of the SN could transmit the data directly to the recipient Application. [0041] When the data processing is done at the Broker level, the Broker may filter out sensitive information so that the Applications only receive that information which they are allowed to receive. By sending information directly from SNs to the Applications, the Applications may obtain additional information that they are not authorised to. Therefore, there is a need for a system that can delegate tasks whilst maintaining the desired level of security. [0042] FIG. 2 illustrates schematically an M2M system according to an embodiment of the present invention and comprises a Broker 11 , an Application Environment 10 , and one or more Sensor Networks (SN) 13 . An Application Environment 10 is associated with one or several Applications 12 and is provided with at least one Trusted Data Processor (TDP) 15 to which a Broker 11 may delegate data processing tasks. [0043] If a Broker 11 has delegated a data processing task to a TDP 15 , then the SNs 13 can provide the data directly to that TDP 15 , which processes the data and provides it to the Application 12 . The data processing performed by the TDP 15 ensures that the Application 12 only receives information that it is authorised to receive. [0044] To ensure that the TDP 15 can be trusted with the unprocessed data, the Broker 11 confirms that a trusted Certificate Authority (CA) has issued the TDP 15 with a public key certificate. The CA ensures that the TDP 15 conforms with its the compliance rules such that a TDP 15 with a valid public key certificate is trusted to receive the same level of sensitive information as the Broker 11 . If a TDP 15 has been compromised then the CA can revoke its certificate. [0045] The Broker 11 comprises Data Reasoner 16 , a Key Generator 17 , a Transmitter 18 and a Receiver 19 . The Data Reasoner 16 analyses a request received from an Application 12 and decides from which SNs 13 the data is going to be collected and how the data is going to be processed. The Key Generator 17 generates keys to be used by the source SNs 13 to encrypt the data. The TDP 15 in the Application Environment 10 decrypts the data from the SNs 13 , processes the data and provides the Application 12 with the processed results. The Application Environment 10 belongs to an M2M service provider and the M2M service provider can use the same TDP 15 for all its Applications. [0046] FIG. 3 schematically illustrates the TDP 15 of FIG. 2 in more detail. The TDP 15 comprises a Data Decryptor 20 , a Data Processing Unit 21 , a Key and Algorithm Decryptor 22 , a Transmitter 24 and a Receiver 23 . The algorithms and keys sent to the TDP 15 , from Broker 11 via the Application 12 , are encrypted so that the Applications cannot use them directly. The Key and Algorithm Decryptor 22 decrypts the algorithms and the keys. The Data Decryptor 20 then uses the keys K 1 , K 2 provided by the Broker 11 to decrypt the data from SNs 13 . The Data Processing Unit 21 uses the processing algorithm F to process the data and provides the results to the Application 12 . The TDP 15 may also comprise a memory unit that could be used to cache the algorithm for re-use on further data, varying only any control parameters as required, or to cache the received data for processing using further algorithms. [0047] It is assumed that the Broker 11 has security associations with the SNs 13 such that, when sensitive information (e.g. keys) is sent from the Broker 11 to SNs 13 , the information is protected from eavesdropping and modifications. By way of example, these security associations could be established using the Internet Key Exchange (IKE) protocol as in the IPsec protocol suite. [0048] The above concept will now be described in more detail with reference to FIG. 4 , which shows a simplified signalling flow diagram in a situation where an Application 12 makes a request for service requiring data from two different SNs 13 . The steps performed are as follows: S 1 . The Application 12 sends a request to the Broker 11 asking for a service. S 2 . The Broker 11 sends a request to the TDP 15 , via the Application 12 , to present its certificate and checks whether the certificate has expired or has been revoked. If the certificate is valid and the Broker 11 successfully authenticates the TDP 15 using the public key contained in the certificate, it continues with step S 3 . Otherwise the Broker 11 rejects the Application's request. S 3 . The Data Reasoner 16 within the Broker 11 analyses the request from the Application 12 and decides from which SNs 13 the data is going to be collected. For each source SN 13 , it instructs the Key Generator 17 to generate a data key K and sends it to the SN 13 . S 4 . The Data Reasoner 16 also produces a data processing algorithm F that identifies the source SNs 13 and provides the algorithm F that the TDP 15 will use to process the data from those SNs 13 . S 5 . The Broker 11 encrypts the data keys K 1 , K 2 (generated by the Key Generator 17 at step S 3 ) and the algorithm F (produced by the Data Reasoner 16 at step S 4 ) with the TDP's public key K TDP and the result (i.e. (K 1 , K 2 , F) K TDP ) is sent to the Application 12 . S 6 . The Application 12 forwards the encrypted data keys K 1 , K 2 and data processing algorithm F (i.e. (K 1 , K 2 , F) K TDP ) received at step S 5 to the TDP 15 . S 7 . The SNs 13 collect data P. For each SN 13 , when the data P is ready, the SN 13 encrypts P with the data key K 1 or K 2 received from the Broker 11 to produce encrypted data C (i.e. C=(P)K). The encrypted data C is sent to the TDP 15 in a communication session. The session can be established according to the procedures described below. S 8 . The Key and Algorithm Decryptor 22 of the TDP 15 decrypts the data keys K 1 , K 2 and the data processing algorithm F by using its private key. It sends the data keys K 1 , K 2 and the algorithm F to the Data Decryptor 20 and the Data Processing Unit 21 respectively. S 9 . The Data Decryptor 20 within the TDP 15 decrypts each input C by using the corresponding data key K 1 or K 2 and recovers the data P. The Data Processing Unit 21 within the TDP 15 processes the plaintext data (P 1 and P 2 as shown in FIG. 3 ) according to the algorithm F, generating a result (R). S 10 . The TDP 15 outputs the result R to the Application 12 . [0059] The data processing acts so as to “filter out” sensitive information, either by removing it or by performing some irreversible modification to it such that the details of this information can no longer be ascertained, with only the processed result being sent to the Application 12 . The unencrypted plaintext data (P 1 , P 2 ) is never exposed outside of the TDP 15 . Given that only the TDP 15 knows its private key, the Application 12 cannot decrypt the data keys provided by the Broker 11 and therefore cannot decrypt the unprocessed data such that the Applications only receive that information which they are allowed to receive [0060] As part of the process of delegating data processing tasks from the Broker 11 to the TDP 15 , the Broker 11 redirects the data traffic from the SNs 13 directly to the TDP 15 , bypassing the Broker 11 . This may require that a communication session be established directly between the SNs 13 and the TDP 15 in the Application Environment 10 . This communication can be done in several ways, such as using an Internet Protocol (IP) or IP Multimedia Subsystem (IMS) connection. The following discussion refers to the use of an IP Multimedia Subsystem (IMS) as an example communication network, but it can also be applied to other networks. [0061] IP Multimedia Subsystem (IMS) is the technology defined by the Third Generation Partnership Project (3G) to provide IP Multimedia services over mobile communication networks. IMS provides a dynamic combination of voice, video, messaging, data, etc. within the same session. The IMS makes use of the Session Initiation Protocol (SIP) to set up and control calls or sessions between user terminals (or user terminals and application servers). SIP makes it possible for a calling party to establish a packet switched session to a called party (using so-called SIP User Agents, UAs, installed in the user terminals) even though the calling party does not know the current IP address of the called party prior to initiating the call. The Session Description Protocol (SDP), carried by SIP signalling, is used to describe and negotiate the media components of the session. Whilst SIP was created as a user-to-user protocol, IMS allows operators and service providers to control user access to services and to charge users accordingly. [0062] If the communication between the SNs 13 and the TDP 15 was to take place over an IMS network this would require that either the SNs have an IMS subscription, or the Broker and the IMS provider are the same entity or that the SNs are able to make use of a third party's IMS subscription. [0063] If the SNs 13 themselves do not have direct access or a subscription to an IMS network, and given that the Broker 11 redirects the data traffic from the SNs 13 directly to the TDP 15 , it is reasonable that the Broker 11 is charged for the traffic. Therefore, a process for accessing a third party network is further presented here. [0064] In order to establish an IMS session, the Broker 11 also provides the gateway 14 of each SN 13 with an indirect Access Token and a session key K SESSION when sending the request for data. In one embodiment, this session key can be computed as a cryptographic one-way function ƒ( ) of the session identifier session_ID and the public key K M2Mbroker of the Broker 11 , i.e. K=ƒ(session_ID, K M2Mbroker ). In one embodiment, the Access Token consists of a signed set of critical information. For example, the token can include the SIP URI of the receiver, conditions to be met, the session identifier, the identity of the Broker 11 and the identity of the IMS Provider (IMSP), all signed using the private key SK M2Mbroker of the Broker 11 , i.e. Access Token=(SIP URI of receiver, conditions, session_ID, Broker, IMSP) sign SK M2Mbroker . [0065] FIG. 5 shows a simplified signalling flow example in a situation where an Application 12 makes a request for service requiring data from an SN 13 wherein, the SN 13 requires the establishment of an IMS Session using the Broker's 11 IMS subscription to communicate directly with the TDP 15 in the Application Environment 10 . The steps performed are as follows: T 1 . As with step S 1 previously described with reference to FIG. 4 , the Application 12 in the Application Environment 10 sends a request to the Broker 11 asking for a service. T 2 . As with step S 2 previously described with reference to FIG. 4 , the Broker 11 sends a request to the TDP 15 , via the Application 12 , to present its certificate and checks whether the certificate has expired or has been revoked. If the certificate is valid and the Broker 11 successfully authenticates the TDP 15 using the public key contained in the certificate, it continues with step T 3 . Otherwise the Broker 11 rejects the Application's request. T 3 . The Broker 11 generates a data key K, equivalent to that generated in step S 3 previously described with reference to FIG. 4 , for encrypting and decrypting the data. In addition, the Broker 11 also generates an Access Token and a session key K SESSION . The Broker 11 sends the data key K, the Access Token and the session key K SESSION to the SN Gateway 14 . T 4 . As with steps S 4 to S 6 previously described with reference to FIG. 4 , the Broker 11 also produces a data processing algorithm F, encrypts the data key K (generated at step T 2 ) and the algorithm F with the public key K TDP of the TDP 15 and the result is sent to the TDP 15 in the Application Environment 10 , via the Application 12 . T 5 . The SN Gateway 14 then sends a REGISTER message including the Access Token to the P-CSCF (not shown) in the Visited IMS 31 . T 6 . The P-CSCF identifies an I-CSCF (not shown) in the Home IMS 30 and forwards the REGISTER message. The I-CSCF in turn determines the S-CSCF (not shown) following reference to the HSS (not shown) and forwards the REGISTER message. T 7 . The SN 13 is currently not authenticated, so the registration request is rejected and a 401 Unauthorised message is returned to the SN 13 with a challenge to authenticate the user. T 8 . The SN 13 and IMS 30 are then mutually authenticated according to standard IMS AKA procedures, using the session key K SESSION . T 9 . Once the SN 13 is registered with the IMS 30 it sends an INVITE message to the SIP URI of the recipient TDP 15 . T 10 . An IMS Session is then established between the SN 13 and the TDP 15 in the Application Environment 10 . Steps S 7 to S 10 previously described with reference to FIG. 4 can then take place directly between SN 13 and the TDP 15 . [0076] In order to implement the process described above, the CSCFs need to understand that the Access Token should be transported to the HSS, and the HSS is required to understand the token, maintain a list of Brokers and their public keys and shared symmetric keys, and to be able to check the conditions. Examples of the conditions could be the time of day, session duration session or results of other sensor measurements etc. This could for instance allow for independent control of when sessions should be initiated, for example, ensuring that a session does not have a privacy impact when related to a video stream from a home. The S-CSCF also needs to be able to enforce these conditions, preventing session initiation if the conditions are not met. The S-CSCF together with the HSS checks the conditions, the signature of the token and computes the key K SESSION using the session_ID and K M2MBroker . K SESSION is then used as a shared secret between the SN and the IMS to perform mutual authentication using AKA without the need for an ISIM. [0077] Once the SN Gateway 14 is authenticated and given a temporary SIP URI, it can initiate the allowed session(s) corresponding to the SIP URI of the receiver and the conditions. [0078] As described above, the data sent from the SNs 13 to the TDP 15 is securely bootstrapped using the data keys K sent by the Broker 11 to both the TDP 15 and the SNs 13 . The explicit method used for this is out of scope of the present invention but, for example, could be based on TLS using pre-shared keys. [0079] When the SN 13 has a subscription to establish a communication channel with the TDP 15 or does not need subscription, the Broker 11 needs only to send the data key K to the SN 13 and the TDP 15 . If a subscription is needed for the SN 13 to establish a communication channel and the SN 13 does not have one, the Broker 11 needs to send the Access Token and the session key K session along with the data key K to the SN 13 . [0080] The above-described embodiments provide for the delegation of data processing to reduce computational load on a Broker while maintaining the security of the data, as it may contain private data that should not be accessible by certain applications. For example, GPS data can provide location information to within a few metres. If an application only requires information regarding the current city of location for its service, it is not appropriate to expose the detailed GPS data to the application as this may violate privacy constraints. In another example, an insurance company may require an individual's health index calculated using various parameters such as the individuals ECG measurements, blood pressure etc. Providing the detailed data of such parameters could also violate some privacy policy. [0081] It will be appreciated by the person of skill in the art that various modifications may be made to the above-described embodiments without departing from the scope of the present invention.	According to a first aspect of the present invention there is provided a method of at least partly delegating processing of data in a machine-to-machine system to reduce computational load on a broker entity 11 while maintaining security of the data to be processed, the broker entity 11 serving as a link between a node 13 of a sensor network providing the data and an application node 12 requesting the data. In the method, at the broker entity 11 , following receipt of a request for processed data from the application node 12 , determining the node to provide the data to be processed, generating a data key for the data-providing node 13 , generating a data-processing algorithm for processing the data in dependence upon the request, sending the data key to the data-providing node 13 , and sending the data key and data-processing algorithm to a remote data-processing entity 15 . At the data-providing node 13 , encrypting the data using the data key and sending the encrypted data to the data-processing entity 15 . At the data-processing entity 15 , decrypting the data using the data key, processing the data using the data-processing algorithm, and sending the processed data to the application node 12.	7
This application is a continuation of prior U.S. Ser. No. 09/181,952, filed Oct. 28, 1998 now U.S. Pat. No. 6,466,548. BACKGROUND OF THE INVENTION The present invention relates to a packet switched network used for transmitting audio data, video data or any other delay sensitive data, and more particularly to a hop by hop loopback system that locates quality of service problems in the packet switched network. Conversations between two or more people include constant acknowledgements. If the conversation is face to face, the acknowledgement can be either visual or audible. Visual acknowledgements are typically in the form of body motions such as a head nod, hand motion, or facial expression. Audible acknowledgements typically come in the form of words or noises such as “I see”, “ok”, “yes”, “um hum”, etc. Phone conversations also require constant acknowledgements. Since phone conversations are not conducted face to face, these acknowledgements must be given audibly. Packet switched networks, such as the Internet, are used for conducting telephone calls. Audio signals from a telephone are converted into voice packets by an originating gateway. The voice packets are then transmitted over the packet switched network to a destination gateway that converts the voice packets back into voice signals that are output to a destination telephone. Delay is a particular problem in packet switched networks that disrupts the interaction and feedback in telephone conversations. For example, if the network has a lot of delay, audio feedback can be misinterpreted. A person completing a statement over the phone may wait for an acknowledgement such as “ok”, “yes”, “I see”, “uh hum”, etc. The packet switched network can delay the voice packets containing the acknowledgement. The delayed acknowledgement may be misinterpreted as confusion, apathy, or rudeness. While in fact, an immediate acknowledgement was given by the listener. If audio signals are delayed too long, the speaker may go onto another subject. When the audio packets do arrive, the speaker does not know what part of the conversation the listener was responding to. These network delays result in disjointed and confusing conversations. Utilities currently exist that can identify end to end network delay. End to end delay is generally defined as the time it takes a packet to go from an originating telephony gateway endpoint to a destination telephony gateway endpoint. One way to measure end to end delay is to put loopback interfaces into the gateway endpoints. A packet sent from the originating gateway is sent to the destination gateway and then automatically looped back to the originating gateway. The roundtrip delay from the originating gateway to the destination gateway and back to the originating gateway is then calculated. A distributed packet switched network includes different subsystems or subnetworks connected together through different network processing nodes such as routers, switches, etc. Any one or more of these subnetworks or processing nodes could be the primary contributor to the end to end delay. End to end delay measurements do not identify where these delays occur in the packet switched network. The subsystems or processing nodes that cause the delay problems, therefore, cannot be located. Existing loopback systems also do not test QoS for voice traffic sent over a packet switched network. During any given telephone conversation, the voice packets may be routed through different paths depending on network congestion and other similar considerations. Also, the voice path for incoming voice packets may be different than the voice path for outgoing voice packets. Existing loopback systems, e.g., ping, can only generate one packet about every second. Thus, these loopback systems do not simulate the traffic conditions that are created with an actual audio packet stream. Additionally, ping is based on ICMP, which may receive different treatment by routers than regular traffic. Accordingly, a need remains for a system that can identify and locate causes of audio QoS problems in a distributed packet switched network. SUMMARY OF THE INVENTION Loopback interfaces are put into routers throughout a packet switched network. When an end to end path in the network is not providing satisfactory Quality of Service (QoS), the delay and jitter characteristics of an audio signal are measured for individual network subsystems between the end to end path. The audio signal is converted into a stream of audio packets and sent hop by hop to the different routers in the network with the loopback interfaces. The QoS for the subsystems are determined by measuring the audio packet stream looped-back from the different routers. Subsystems with QoS problems can be identified by comparing the results of adjacent hop by hop loopbacks. If a loopback from a first router has minimal delay and the loopback from a next router has excessive delay, the QoS problem exists in the subsystem between the two routers. The capacity of the network can then be adjusted as necessary according to the measured transmission delay. For example, telephone calls may be rerouted around the problem subsystem through a different network path or additional equipment may be added to the problem subsystem to increase capacity. Existing network utilities such as trace route can be used to automatically calculate routes in the packet switched network between a source gateway and a destination gateway. Loopback calls are then automatically sent to routers with loopback interfaces. The loopback delays are then calculated for each of the loopback calls to determine the QoS for the different network subsystems. Hop by hop loopback is especially useful to Internet Service Providers (ISPs) that buy network services for different backbone carriers. The QoS can be separately measured for both the ISP network and the backbone carrier networks to determine whether the backbone carrier is meeting agreed upon QoS. The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention which proceeds with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a packet switched network using the hop by hop loopback system according to the invention. FIG. 2 is a schematic diagram of the network in FIG. 1 showing audio loopbacks performed from different processing nodes in the network. FIG. 3 is a block diagram showing how the hop by hop loopback system operates. FIG. 4 is a schematic diagram of the network in FIG. 1 reconfigured according to measurements taken by the hop by hop loopback system in FIG. 2 . FIG. 5 is a detailed block diagram showing how multilevel hop by hop loopback is used in a Voice over IP gateway. DETAILED DESCRIPTION Referring to FIG. 1 , a distributed packet switched network 12 having a hop by hop loopback system includes multiple subnetworks 18 , 22 , 24 , 26 and 28 connected together through different network processing nodes Ra, Rb, Rc, Rd and Re. The subnetworks comprise different Local Area Networks (LANs), Wide Area Networks (WANs) and/or Public Switched Telephone Networks (PSTNs). The processing nodes comprise devices such as routers, switches, communication links etc. These different processing nodes are referred to generally below as routers. A telephone 14 is connected to the network 12 through a Voice over IP (VoIP) gateway 16 . A telephone 31 is connected to the network 12 through a VoIP gateway 30 . The VoIP gateways 16 and 30 are capable of converting back and forth between analog voice signals and audio packets. The gateways 16 and 30 also have end to end loopback capability. Some VoIP gateways with loopback capability include the Model Nos. 2600, 3600 and 5300 manufactured by Cisco Systems, Inc., 170 West Tasman Drive, San Jose, Calif. 95134-1706. An end to end telephone call between the gateways 16 and 30 may have unacceptable end to end delay “d”. A system administrator does not know where the primary cause of the delay is occurring in network 12 . A delay do may exist between telephone 14 and router Ra, a delay d 1 may exist between the router Ra and a router Rd, a delay d 2 may exist between router Rd and router Re and a delay d 3 may exist between router Re and telephone 31 . These delays from the subnetworks and processing nodes between the two endpoints 18 and 30 are additive generating the overall end to end delay d=d 0 +d 1 +d 2 +d 3 . One of more of these delays may be the primary contributor to the overall delay d. These delays can be caused by a variety of different reasons such as router congestion or a slow network link along the communication path. To perform effective voice QoS testing, the invention places the same loopback interface used in VoIP gateways into non-voice routers, such as routers Ra, Rb, Rc and Rd. The loopback interfaces allow hop by hop loopback testing described below. Any type of network router can be installed with the loopback interface. For example, the Model Nos. 7200, 7500, and 4000 all manufactured by Cisco Systems, Inc. are standard routers used in packet switched networks that can be installed with loopback interfaces. The loopback interfaces are implemented in software in the routers. The loopback interfaces receive the audio packets and then send the audio packet stream back out uninterpreted to the originating gateway. This provides reliable audio QoS measurements for any individual subsystem inside the network 12 . Separate loopback software interfaces can be used for each supported QoS application. For example, a separate loopback interface can be provided for RTP (protocol carrying voice for H.323, SIP and SGCP), FRF. 11 VoFR and SNA. Referring to FIG. 2 , the network administrator determines if there is a QoS problem by performing an end to end loopback call from gateway 16 to gateway 30 . The description below assumes that gateway 16 originates the hop by hop loopbacks. However, the loopbacks can be originated from any gateway in the network. Voice packets are sent out from gateway 16 and then looped back by gateway 30 to gateway 16 . The gateway 16 measures the delay required for the voice packets to loop through the entire network 12 . If the QoS for the end to end loop back is poor (large delay), the hop by hop loopback system is used to isolate the primary source of the delay. The network administrator has a topology of the network 12 that identifies the addresses for the routers, such as Ra, Rb, Re, Rd and Re, that each have a loopback interface according to the invention. To isolate the sublink creating the delay, the system administrator initiates a first loopback call 32 to router Ra. The first loopback call 32 may indicate either a large delay or a small acceptable delay between originating gateway 16 and router Ra. If the delay is small, the problem exists either between router Ra and gateway 30 or along an alternate communication path formed by routers Rb and Re. The system administrator continues hop by hop loopback calls through the network 12 until the primary location of the delay is isolated. For example, a second loopback call 33 is initiated from gateway 16 to router Rd. If substantial delay is detected in the second loopback call 33 , the QoS problem exists between router Ra and router Rd. If the QoS problem does not appear in the loopback calls 32 and 33 , a loopback 34 may be tried in an alternate network path. If the QoS is good for loopback 34 , then the next hop by hop loopback call is made to Rc and a next loopback call possibly made to router Re. The hop by hop loopbacks can be initiated in any sequence depending on the network configuration. The sequence described above is merely one example. Internet utilities such as Ping diagnose Internet Protocol (IP) connections. Ping can send a signal to any Internet-connected computer. Ping generates data on the number of packets transmitted and received. The problem with Ping is that only about one data packet is sent every second. QoS audio problems are often caused by network congestion. Because PING does not generate packets at audio communication rates of one audio packet every 20 milliseconds, audio QoS problems may not be detected. Test loads generated during hop by hop loopback simulate a voice stream generated during a typical telephone call. The hop by hop loopback system can therefore, measure the actual jitter or absolute delay that an audio packet stream actually experiences in the network 12 . Referring to FIG. 3 , existing Internet utilities such as Pathcar can calculate the different routes through network 12 . Block 36 uses utilities like Pathcar to calculate a route table for the network 12 . The route table is used in block 38 to identify the topology of the network 12 and to identify the routers that have the loopback feature of the invention. Loopback calls are initiated to the identified routers in block 40 . The loopback delays are then calculated in block 42 . From the calculated delays, a network administrator is then able to determine the source of the QoS problem. The loopback calls can also be automatically initiated and measured by software in the gateway 16 . Loopback calls are made incrementally starting from either the closest or furthest loopback interface from the originating gateway 16 . The loopback calls are then made automatically hop by hop through the network 12 , if necessary, to every router with a loopback interface. The loopback delays are then presented in a list to the system administrator. The loopback calls can also be initiated automatically through the network until a certain delay threshold is exceeded. Then only the loopback path exceeding the delay threshold is identified to the network administrator. Once the location and source of the QoS problem are identified, steps are taken by the system administrator to correct the QoS problem. If the problem is congestion at a router location, priority bits can be set in the audio packets to increase priority. Different router queuing techniques can also be selected to more efficiently process the audio packets. In addition, faster interfaces, additional routing resources, or upgraded routing resources can be installed at the source of the congestion. Referring to FIG. 4 , the hop by hop loopback system can also be used for capacity planning. Two routes are shown from the originating gateway 16 to the destination gateway 30 . A first path 40 goes through routers Ra and Rd. The second route 42 goes through routers Rb and Rc. The hop by hop loopback system provides a way to quantitatively determine the delay for these individual paths 44 and 46 . A system administrator can perform capacity planning around the two paths. For example, the hop by hop loopback delay for path 44 may be substantially less than path 46 . The network can then be configured to route telephone calls through path 44 . Referring to FIG. 5 , VoIP gateways include a Public Switched Telephone Network (PSTN) interface 60 that receives Pulse Code Modulated (PCM) audio signals from a PSTN network 62 . A Digital Signal Processor (DSP) subsystem 58 encodes the audio signals from the PSTN interface 60 and decodes audio packets from an IP packet router 56 . The IP packet router 56 establishes connections for routing the audio packets to the endpoint 16 in the network 12 . The multilevel loopbacks are described below in terms of gateway 30 . However, the multilevel loopbacks can be performed in any VoIP gateway in network 12 . A dialplan mapper (not shown) supports multilevel loopback in the gateway 30 so that users or troubleshooters can invoke loopback from any VoIP capable endpoint. The dialplan mapper is described in detail in copending application entitled: SIGNALING STATE MANAGEMENT SYSTEM FOR PACKET NETWORK GATEWAYS; Ser. No. 09/107,071; filed on Jun. 29, 1998 which is herein incorporated by reference. The dialplan mapper to various loopback levels maps a dialstring. The syntax is: loopback:where. “Where” is one of three loopback levels, RTP, Compressed, and Uncompressed in the gateway 30 . To understand how this works, assume the following configuration in the dial plan mapper of VoIP gateway 30 called “testme”: +1408526\311→loopback:RTP +1408526\312→loopback:Compressed +1408526\313→loopback:Uncompressed The dial plan maps for other routers or gateways have the extra entry: 7→dns:testme.cisco.com session=cisco controlled — load best — effort With this setup, different levels of the gateway 30 can be tested from any telephone in network 12 . For local loopback it is assumed that the calling line has been assigned a number like +1408526xxxx. Phone 31 is picked up and one of the numbers 311, 312, or 313 is dialed. If the phone 31 is on the other side of a PBX or a PSTN 62 , enough digits have to be dialed to get the call completed to the VoIP gateway 30 . The dotted lines 50 , 52 , 54 , 64 , 66 and 68 show the different loopback paths initiated by the different telephone numbers. Uncompressed 64 : A Pulse Code Modulated (PCM) voice signal coming into the DSP 58 from the PSTN interface 60 is turned around and sent back out PSTN 62 allowing testing of the transmit -> receive paths in the telephony end point 31 . Compressed 66 : A compressed voice signal coming out of a codec in the DSP subsystem 58 is fed back into a decompressor through a jitter buffer. In addition to testing the telephony endpoint, the encode and decode paths in the DSP 58 are tested without involving data paths or packet handling of the IP packet router 56 . RTP 68 : A session application in the IP packet router 56 sets up an RTP stream to itself. RTP is a “Real-Time Transport Protocol” used for transporting voice information and is described in RTP—Internet Request for Comments 1889. The router 56 allocates a port pair and opens the appropriate User Datagram Protocol (UDP) sockets. The router 56 performs full RTP encapsulation, sends the packets to the loopback IP address, receives the RTP packets, and hands the compressed voice back to the CODEC in DSP subsystem 58 . This tests the entire local processing path, both transmit and receive, in the router 56 , as well as all the other paths described above. A remote loopback is an end to end loopback initiated from telephone 14 to the gateway 30 all the way across the packet switched network 12 . To initiate a remote loopback, the phone 14 is picked up and the number 7311, or 7312 or 7313 is dialed. Again, if the telephone 14 is connected to the gateway 16 through a PBX or PSTN, enough digits have to be dialed to get the call completed to the VoIP gateway 16 . The dial plan in gateway 16 initiates an IP session to testme.cisco.com, and passes the lower part of the number, say 311, to the gateway 30 . When the session application on gateway 30 extracts the number with 31x in it, loopback is invoked as follows: RTP 54 : RTP packets from the network 12 are decapsulated and immediately reencapsulated in the outbound RTP stream, using the same media clock (i.e., time stamp) as the received packet. The RTP packets are then sent back to the source gateway 16 as if the voice signals had originated on a telephony port on testme gateway 30 . Compressed 52 : RTP packets received from the network 12 are decapsulated and passed to the DSP subsystem 58 . Instead of feeding the audio packets into the CODEC for decompression, they are immediately sent back to the IP session application in router 56 as if they had originated locally and been compressed. The voice packets may or may not be dejittered before being sent back to router 56 . Uncompressed 54 : In addition to the above, the voice samples are sent all the way through the CODEC in DSP 58 and then turned around instead of being sent to the telephony endpoint 31 . QoS problems may occur in the RTP path, the DSPs that compress and decompress the audio signals, or the PSTN path after the audio packets have been uncompressed into the speech as it actually is suppose to sound coming out of the gateway 30 . Multilevel hop by hop loopback separately tests each one of these paths so QoS problems can be further located inside each VoIP gateway. Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention can be modified in arrangement and detail without departing from such principles. I claim all modifications and variation coming within the spirit and scope of the following claims.	Loopback interfaces are put into routers in a packet switched network. When an end to end Quality of Service (QoS) path is not performing adequately, the delay and jitter characteristics are measured for individual network subsystems. An audio signal is converted into a stream of audio packets and sent hop by hop to the different routers in the network having the loopback interface. QoS is determined by looping back the stream of audio packets from the different routers. If necessary, the network is reconfigured according to loopback delay in the individual network subsystems. Reconfiguration can comprise routing telephone calls through different paths in the network or adding additional equipment to increase capacity.	7

Subsets and Splits

No community queries yet

The top public SQL queries from the community will appear here once available.