this module implements a rotor - based encryption algorithm, contributed by lance ellinghouse. the design is derived from the enigma device, a machine used during world war ii to encipher messages. a rotor is simply a permutation. for example, if the character ` a ' is the origin of the rotor, then a given rotor might map ` a ' to ` l ', ` b ' to ` z ', ` c ' to ` g ', and so on. to encrypt, we choose several different rotors, and set the origins of the rotors to known positions ; their initial position is the ciphering key. to encipher a character, we permute the original character by the first rotor, and then apply the second rotor ' s permutation to the result. we continue until we ' ve applied all the rotors ; the resulting character is our ciphertext. we then change the origin of the final rotor by one position, from ` a ' to ` b ' ; if the final rotor has made a complete revolution, then we rotate the next - to - last rotor by one position, and apply the same procedure recursively. in other words, after enciphering one character, we advance the rotors in the same fashion as a car ' s odometer. decoding works in the same way, except we reverse the permutations and apply them in the opposite order. the available functions in this module are : rotor objects have the following methods : an example usage : > > > import rotor > > > rt = rotor. newrotor ( ' key ', 12 ) > > > rt. encrypt ( ' bar ' ) ' \ 2534 \ 363 ' > > > rt. encryptmore ( ' bar ' ) ' \ 357 \ 375 $ ' > > > rt. encrypt ( ' bar ' ) ' \ 2534 \ 363 ' > > > rt. decrypt ( ' \ 2534 \ 363 ' ) ' bar ' > > > rt. decryptmore ( ' \ 357 \ 375 $ ' ) ' bar ' > > > rt. decrypt ( ' \ 357 \ 375 $ ' ) ' l ( \ 315 ' > > > del rt the module ' s code is not an exact simulation of the original enigma device ; it implements the rotor encryption scheme differently from the original. the most important difference is that in the original enigma, there were only 5


by elizabeth howard a lot about thermals, but now i understand them. thanks to dr. ian worley, pilot and professor at the university of vermont, i went up in the sky and found out what it feels like to fly in a thermal. take my students on aerial field trips because we can see things from the sky that we can ' t see so well from the ground, " said dr. worley. " but more excitingly, we can have a feel of the sky and learn its shape — what ’ s going on in the air — because though the air is sometimes invisible we can feel it with the airplane. looking for thermals aboard his plane and headed for the sky. off looking for thermals, those rising columns of air that take gliders, hawks and butterflies to higher heights so they can glide to the next thermal and find their way south during migration. " but where would we find a thermal? and, i wondered nervously, what would it feel like to fly a small plane a tell - tale sign spotted a fluffy cumulous cloud and banked the plane to the left. a cumulous cloud is the tell - tale sign of a thermal. the cloud forms when a column of air rises and cools at higher altitudes. the moisture in the air condenses and forms the cloud. going to fly to it and see if we can get an upward rise of air, which we ' ll feel as a bump. and if it ' s a really good bump we ' ll feel it in the seat of our pants, " he said. so off we flew toward the cloud. watch the video clip and ready the transcript to find out what happened. special thanks to dr. ian worley for the invitation to fly, for his colorful commentary, skillful flying, and especially for " watching for a safe place to land " throughout the flight — but never needing it. science education standards materials can exist in different states? solid, liquid, and gas. some common materials, such as water, can be changed from one state to another by heating or cooling. ( k - 4 ) formed by the condensation of water vapor, affect weather and climate. forces will cause changes in the speed or direction of an object ' s motion. compute fluently and make reasonable estimates. solving solve problems that arise in mathematics and in other contexts.


there ' s a distinction to be made between two notions : foliations and distributions. a distribution is the data, at each point m of m, of a subspace of tm ( m ). these subspaces are all of the same dimension ( say r ), and depend smoothly on the point m, which means that they are generated by r smooth vector fields. a foliation is a partition of the manifold into ( not necessarily closed ) submanifolds, such that, locally, this partition looks like the standard decomposition of ℝn into translates of ℝd. ok, there ' s a caveat in my description since a same leaf could come infinitely many often in the neighborhood of a given point m. anyways... i ' m assuming that you know what a foliation is. foliations of m form a subset of distributions on m. the frobenius integrability criterion ( mentioned by tom in him remark ) states that a distribution d comes from a foliation iff for any vector fields v and w tangent to d, their lie bracket is again tangent to d. it turns out that that criterion is always satisfied for one - dimensional distributions, and so one - dimensional distributions are indeed in bijection with one - dimensional foliations. but that ' s no longer true for r ≥ 2. the operation of taking orthogonal complement is a very good operation for distributions : it ' s always well defined, and the orthogonal complement of the orthogonal complement is the distribution you started with. but the orthogonal complement of a foliation is typically only a distribution. the standard example that illustrates that situation is the vector field sin ( z ) d / dx + cos ( z ) d / dy on ℝ3. it defines a perfectly good foliation, but its orthogonal fails to satisfy the frobenius integrability criterion, and therefore fails to be a foliation ( in this particular case, it ' s a contact structure, another beautiful mathematical notion... ). ah! you also wanted the foliation to be defined by the orbits of a group acting by isometries... that can be arranged : take the action of s1 on s3 given by the hopf fibration. the orthogonal distribution is the standard contact structure on s3. you also said that you wanted you riemanninan manifold to be flat... in that case, you can take ℝ4 = with its s1 -


the theory of the two truths in tibet focuses on the philosophical issues arising from and associated with these themes. therefore our concern in this article is not historical evolution of the schools, or the philosophers and the ideas to which they each are associated, our concern is rather, first and foremost philosophical. - 1. nyingma - 2. kagyu - 3. sakya - 4. gelug - 5. implications - academic tools - other internet resources - related entries longchen rabjam sets out the course of the nyingma theory of the truths and the later philosophers of the school took similar stance without varying much in essence. in treasure he begins the section on the madhyamaka theory of the two truths as follows : “ the madhyamaka tradition is the secret and profound teachings of the [ sakya ] muni. although it constitues five ontological categories, the two truths subsume them. ” ( longchen, 1983 : 204f ) nyingma defines conventional truth as consisting of unreal phenomena that appear to be real to the erroneous cognitive processes of the ordinary beings while ultimate truth is reality which transcends any mode of thinking and speech, one that unmistakenly appears to the nonerroneous cognitive processes of the exalted and awakened beings. in other words ( 1 ) ultimate truth represents the perspective of epistemically correct and warranted cognitive process of exalted beings ( ‘ phags pa ) ; whereas ( 2 ) conventional truth represents the perspective of epistemically deceptive and unwarranted cognitive processes of the ordinary beings. ( mipham rinpoche 1993d : 543 – 544 ) let us consider these two definitions turn by turn. nyingma supports definition ( 1 ) with two premises. the first one says that cognitive processes of the exalted ( ‘ phags pa ) and awakened beings ( sang rgyas ) are epistemically correct and non - deceptive, because “ it is in relation to this cognitive content that the realisation of the ultimate truth is so designated. the object of an exalted cognitive process consists of the way things really are ( gshis kyi gnas lugs ), phenomena as they really are ( chos kyi dbyings ) which is undefiled by its very nature ( rang bzin dag pa ). ” ( longchen 1983 : 202f ) however ultimate truth for nyingma is not an object per se in the


chos kyi dbyings ) which is undefiled by its very nature ( rang bzin dag pa ). ” ( longchen 1983 : 202f ) however ultimate truth for nyingma is not an object per se in the usual sense of the word. it is object only in the metaphorical sense. “ from the [ ultimate ] perspective the meditative equipoise of the realised ( sa thob ) and awakened beings ( sangs rgyas ), there exists neither object of knowledge ( shes bya ) nor knowing cognitive process ( shes byed ) and so forth, for there is neither object to apprehend nor the subject that does the apprehending. even the exalted cognitive process ( yeshes ) as a subject ceases ( zhi ba ) to operate. ” ( longchen 1983 : 201f ) therefore “ at this stage, [ nyingma ] accepts the total termination ( chad ) of all the continua ( rgyun ) of the cognitive processes ( ‘ jug pa ) of the mind ( sems ) and mental factors ( sems las byung ba ). this exalted cognitive process which is inexpressible beyond words and thoughts ( smra bsam brjod du med pa ' i yeshes ), and thus is designated ( btags pa ) as a correct and unmistaken cognitive process ( yang dag pa ' i blo ma khrul ba ) as it knows the reality as it is. ” ( longchen 1983 : 201f ) the second premise comes from nyingma ' s transcendent theory. according to this theory ultimate truth constitutes reality and the reality constitutes transcendence of all elaborations. reality is that which cannot be comprehended by the means of linguistic and conceptual elaboration, as it is utterly beyond the grasp of words and thoughts which merely defile the cognitive states. given that exalted beings are free of defiled mental states, all forms of thoughts and conceptions are terminated in their realization of the ultimate truth. ultimate truth transcends all elaborations, thus remains untouched by the philosophical speculations. ( longchen, 1983 : 203f ) “ in short the characteristic of [ ultimate truth ] is that of nirvana, which is profound and peaceful. it is intrinsically unadulterated domain ( dbyings ). the cognitive process by means of which ultimate truth is realized must therefore be free from all cognitive limitations ( sg


ultimate truth ] is that of nirvana, which is profound and peaceful. it is intrinsically unadulterated domain ( dbyings ). the cognitive process by means of which ultimate truth is realized must therefore be free from all cognitive limitations ( sgribs pa ), for it is disclosed to the awakened beings ( sangs rgyas ) in whose exalted cognitive processes appear the objects as they really are without being altered. ” ( longchen, 1983 : 204f ) nyingma ' s defence of the definition ( 2 ) also has two premises. the first one comes from its theory of error, the most commonly used by the nyingma philosophers. according to this theory, conventional truth is, as matter of fact, an error confined to the ordinary beings ( so so skye bo ) who are blinded by the dispositions ( bag chags ) of confusion ( ma rig pa ). it is argued that under the sway of confusion the ordinary beings falsely and erroneously believe in the reality of entirely unreal entities and the truth of wholly false epistemic instruments, just like the people who mistakenly grasps cataracts and falling hairs to be real objects. conventional truths are mere errors that appear real to the ordinary beings, but they are in fact no more real than the falling hairs that are reducible into the “ modes of apprehensions ” ( snang tshul ). ( mipham rinpoche 1993c : 3, 1977 : 80 – 81ff, 1993d : 543 – 544 ) the second premise comes from its representationalist or elaboration - theory which says that conventional truths constitute merely mental elaborations ( spros pa ) represented to appear ( rnam par snang ba ) in the minds of the ordinary beings as if they are realities having the subject - object relation. they are thus deceptive since they are produced through the power of the underlying cognitive confusion or ignorance, and that they do not cohere with any corresponding reality externally. confusion is samvrti because it conceals ( sgrib ) the nature, it fabricates all conditioned phenomena to appear as if they are real. even though conventional truths are to be eventually eradicated ( spang bya ), the representational images of the conventional reality will nevertheless continue to appear in the minds of even those who are highly realized beings, that is, until they achieved a complete cessation of mind and mental states. ( longchen, 1983 : 203f ) it is argued that when the


reality will nevertheless continue to appear in the minds of even those who are highly realized beings, that is, until they achieved a complete cessation of mind and mental states. ( longchen, 1983 : 203f ) it is argued that when the eye that is affected by cataracts mistakenly sees hairs falling in containers, the healthy eye that is not affected by cataracts does not even perceive the appearances of falling hairs. likewise, those who are affected by the cataracts of afflictive confusion see things as intrinsically real, hence for them things are conventionally real. those noble beings who are free from the afflictive confusion and the awakened beings who are free from even the non - afflictive confusion see things as they are ( ultimate truth ). just as the person without cataracts does not see the falling hairs, the noble beings and awakened beings do not see any reality of things at all. mipham rinpoche also proposes another definition of the two truths which diverges significantly from the one we saw. as we saw longchen ' s definition is based on two radically opposed epistemic criteria whereas mipham ' s definition, as we shall see, has two radically opposed ontological criteria — one that withstands reasoned analysis and the other that does not withstand reasoned analysis. in his clearing dhamchoe ' s doubts ( dam chos dogs sel ), mipham says that : “ reality as it is ( de bzhin nyid ) is established as ultimately real ( bden par grub pa ). conventional entities are actually established as unreal, they are subject to deception. being devoid of such characteristics ultimate is characterized as real, not unreal and not non - deceptive. if this [ reality ] does not exist, ” in mipham ' s view, “ than it would be impossible even for the noble beings ( arya / phags pa ) to perceive reality. they would, instead, perceive objects that are unreal and deceptive. if that is the case, everyone would be ordinary beings. there would be no one who will attain liberation. ” ( 1993a : 602 ) mipham anticipates objections to his definition from his gelug opponents when he writes, “ someone may object : although ultimate truth is real ( bden p ), its reality is not established ultimately ( bden grub ), because to be established ultimately is for it to withstands reasoned analysis ( rigs pas dpyad bzod )


a horse or an elephant appearing in a dream. when it is subjected to logical analysis, it finally boils down to the interdependent inner predispositions. and this is at the heart of buddhist philosophy. ” ( mipham 1977 : 159 – 60ff ) following on from its definition, nyingma argues that there is no one entity that can be taken as the basis from which divides the two truths ; since there is no one entity which is both real ( true ) and unreal ( false ). hence it proposes the two truths division based on the two types of epistemic practices “ because it confirms a direct opposition between that which is free of the elaborations and that which is not free of the elaborations, and between what is to be affirmed and what is to be negated excluding the possibility of the third alternative. thus it ascertains the two. ” ( longchen, 1983 : 205 – 206ff ) nyingma has two key arguments to support the claim the two truths division is an epistemic. the first argument states, “ it is definite that we posit the objects ( yul rnams ) in dependence upon the subjects ( yul can ). the subjects are exclusively two types — they are either ultimately ( mthar thug pa ) fallacious cognitive processes ( khrul ba ' i blo ) or ultimately ( mthar thug pa ) non - fallacious cognitive processes ( ma ‘ khrula ba ' i blo ). the fallacious cognitive processes posit [ conventional truth ] — all samsaric phenomena — whereas as the non - fallacious cognitive processes posit the [ ultimate ] reality. therefore it is due to the cognitive processes that we posit the objects in terms of two [ truths ] ” ( longchen, 1983 : 206f ) the second argument states that ultimate truth is not an objective domain of the cognitive processes with the representational images ( dmigs bcas kyi blo ' i spyod yul ), for the reason that it may be known by means of the exalted cognitive processes ( yeshes ) with no representational image ( dmigs pa med ). ( longchen, 1983 : 206f ) in contrast conventional truth is an objective domain of the cognitive processes with the representational images ( dmigs bcas kyi blo ' i spyod yul ), for the reason that it may be known by means of the cognitive processes having the representational images (


an objective domain of the cognitive processes with the representational images ( dmigs bcas kyi blo ' i spyod yul ), for the reason that it may be known by means of the cognitive processes having the representational images ( dmigs bcas kyi blo ' i spyod ul ). nyingma categorically rejects commitment to any philosophical position, for it would entail a commitment to, at least, some forms of elaborations. this is so since “ the prasangika rejects all philosophical systems, and does not accept any self - styled philosophical elaboration ( rang las spros pas grub mtha ’ ). ( longchen, 1983 : 210ff ) the prasangika therefore presents the theory of the two truths and so forth by merely designating them in accordance with the mundane fabrications ( sgro btags ). ( longchen 1983 : 211f ) “ therefore ultimate truth which is transcendent of all elaborations cannot be expressed either as identical to or separate from the conventional truth. they are rather merely different in terms of negating the oneness. ( longchen, 1983 : 192 – 3ff, mipham 1977 : 84f ) interestingly mipham rinpoche also says that “ the two truths constitute a single entity but different conceptual identities ( ngo bo gcig la ldog pa tha dad ). “ this is because, ” he says, “ appearance and emptiness are indistinguishable. this is ascertained through reliable cognitions ( tshad ma ) by means of which the two truths are investigated. what appears is empty. if emptiness were to exist separately from what appears, the reality of that [ apparent ] phenomenon would not be empty. thus the two [ truths ] are not distinct. ” ( mipham 1977 : 81f ) the identity of ultimate truth at issue here, according to mipham, is that of absolute ultimate ( rnam grangs min pa ' i don dam ste ), rather than provisional ultimate. this is because the kind of ultimate truth under discussion when we are discussing its relation with conventional truth is the ultimate truth “ which is beyond the bound of any expression, although it is an object of direct perception. ” ( mipham 1977 : 81f ) according to karmapa mikyo dorje, atisha and his followers in tibet, are the authoritative former masters of the prasangika. it is this line of reading of


the cognitive process that sees unreal phenomena ( brdzun pa mthong ba ) from the perspective of the ordinary beings whose cognitive processes are obscured by the cataracts of confusion. conventional truth is unreal, for it does not exist in the manner in which it is perceived by the confused cognitive processes of the ordinary beings. ( mikyo dorje 2006 : 269 – 70 ) karmapa mikyo dorje puts the point in this way. “ take a vase as one entity, for instance. it is a conventional entity, for it is a reality for the ordinary beings, and it is found to be the basis from which arise varieties of hypothetical fabrications. the exalted beings, ” he argues, “ however, do not see any of these [ fabrications ], anywhere, whatsoever, and this mode of seeing by way of not seeing anything at all is termed as the seeing of the ultimate. therefore the two truths, in this sense, are not distinct. they are differentiated from the perspective of the cognitive processes that are either erroneous or non - erroneous. ” ( mikyo dorje, 2006 : 274 ) although, like nyingma and sakya it is the view of kagyu to maintain that erroneous cognitive process represents the nature of the ordinary beings, whereas non - erroneous cognitive processes represent the exalted beings. however, unlike nyingma and sakya, kagyu insists that the distinctions between the two truths has nothing to do with the perspective of the exalted beings. everything, it claims, has to do with how ordinary beings fabricate things erroneously — one more real than the other — and that it has nothing to do with how exalted beings experience things. “ even this distinction is made from the point of view of the cognitive process of the childish beings. since all things the childish beings perceive are characteristically unreal ( brdzun pa ) and deceptive ( bslu ba ), they constitute the conventionality. the exalted beings, however, do not perceive at all anything in the way in which the childish beings perceive and fabricate. so ultimate truth is, according to kagyu, that which is unseen and unfound by the exalted beings since it is the way things really are. therefore both the truths are taught for the pedagogical reasons in accord with the perspective of the childish beings, but not because the exalted beings experienced the two


the third is the relativity argument which says, “ they are all defined relative to one another — unreality is relative to reality and reality is relative to unreality. because one is defined relative to the other, one to which it is related ( ltos sa ) could not be identical to that which it relates ( ltos chos ). this is because it is contradictory for one thing to be both that which relates ( ltos chos ) and the related ( ltos sa ). nor is it the case that they are distinct because, ” according to kagyu ' s view, “ when the related is not established, so is the other [ i. e., one that relates ] not established. hence there is no relation. if one insists that relation is still possible, then such a relation would not be relative to another. ” ( karmapa mikyo dorje, 2006 : 285 – 86 ) so from these three arguments, kagyu concludes that the two truths are neither expressible as identical nor distinct. it argues that “ just as the conceptual images of a golden vase and a silver vase do not become distinct on the account of them not being expressed as identical. likewise these images do not become identical on the account of them not being expressed as distinct. ” ( mikyo dorje, 2006 : 286 ) sakya ' s theory of two truths is defended in the works of the succession of sakya scholars — sakya pandita ( 1182 – 1251 ), rongton shakya gyaltsen ( rong ston sakya rgyal tshan, 1367 – 1449 ), the translator taktsang lotsawa ( stag tsang lo tsa ba, 1405 –? ), gorampa sonam senge ( go rams pa bsod nams seng ge, 1429 – 89 ) and shakya chogden ( sakya mchog ldan, 1428 – 1509 ). in particular gorampa sonam senge ' s works are unanimously recognised as the authoritative representation of the sakya ' s position. sakya agree with nyingma and kagyu in maintaining that the distinction between the two truths is merely subjective processes, and that the two truths are reducible to the two conflicting perspectives. ( sakya pandita 1968a : 72d, rongton shakya gyaltsen n. d. 7f, taktsang lotsawa


subjective processes, and that the two truths are reducible to the two conflicting perspectives. ( sakya pandita 1968a : 72d, rongton shakya gyaltsen n. d. 7f, taktsang lotsawa n. d. : 27, shakya chogden 1975a : 3 – 4ff, 15f ) — “ although there are not two truths in terms of the object ' s ontological mode of being ( gnas tshul ), the truths are divided into two in terms of [ the contrasting perspectives of ] the mind that sees the mode of existence and the mind that does not see the mode of existence … this makes perfect sense. ” ( gorampa 1969a : 374ab ) since it emphasizes the subjective nature of the distinction between the two truths, it proposes “ mere mind ” ( blo tsam ) to be the basis of the division. ( gorampa 1969a : 374ab ) it aruges that “ here in the madhyamaka system, the object itself cannot be divided into two truths. conventional truth and ultimate truth are divided in terms of the modes of apprehension ( mthong tshul ) — in terms of the subject apprehending unreality and the subject apprehending reality ; or in terms of mistaken and unmistaken apprehensions ( ‘ khrul ma ‘ khrul ) ; or deluded or undeluded apprehensions ( rmongs ma rmongs ) ; or erroneous or nonerroneous apprehensions ( phyin ci log ma log ) ; or reliable cognition or unreliable cognitions ( tshad ma yin min ). ” ( gorampa 1969a : 375b ) he also adds that : “ the position which maintains that the truths are divided in terms of the subjective consciousness is one that all prasangikas and svatantrikas of india unanimously accepted because they are posited in terms of the subjective cognitive processes depending on whether it is deluded ( rmongs ) or nondeluded ( ma rmongs ), a perception of unreality ( brdzun pa thong ba ) or a perception of reality ( yang dag mthong ba ), and mistaken ( khrul ) or incontrovertible ( ma khrul ). ( 1969a : 384c ) sakya ' s advances two reasons to support its position. first, since the minds of ordinary beings are always deluded, mistaken


606b ) by “ conventional mind, ” gorampa means the ignorant mind of an ordinary being experiencing the phenomenal world. in other words, conventional truth is described as “ truth ” only from the perspective of ignorance. it is a truth projected ( sgro brtag pa ) by it and taken for granted. sakya equates conventional truth with “ the appearances of nonexistent entities like illusions. ” ( gorampa 1969c : 287c ) it follows sakya pandita on this point who puts it : “ conventional truths are like reflections of the moon in the water — despite their nonexistence, they appear due to thoughts. ” ( sakya pandita 1968a : 72a ) according to sakya pandita “ the defining characteristic of conventional truth constitutes the appearances of the nonexistent objects. ” ( 1968a : 72a ) in this sense, conventional truths “ are things apprehended by the cognition perceiving conventional entities. those very things are found as nonexistent by the cognition analyzing their mode of existence that is itself posited as the ultimate. ” ( gorampa 1969a : 377a ) since mere mind is the basis of the division of the two truths wherein ultimate truth — wisdom — alone is seen as satisfying the criterion of truth, so conventional truth — ignorance — cannot properly be taken as truth. wisdom and ignorance are invariably contradictory, and thus the two truths cannot coexist. sakya argues, in fact, that conventional truth must be negated in the ascent to ultimate truth. given wisdom ' s primacy over ignorance, in the final analysis it is ultimate truth alone that must prevail without its merely conventional counterpart. conventional truth is an expedient means to achieve ultimate truth, and the buddha described conventional truth as truth to suit the mentality of ordinary beings. ( gorampa 1969a : 370b ) the two truths are thus categorized as a means ( thabs ) and a result ( thabs byung ). conventional truth is the means to attain the one and only ultimate truth. according to this view, then, the relationship between the two truths is equivalent to the relationship between the two conflicting perspectives — namely, ignorance and wisdom. the question now arises : how is ignorance related to wisdom? or conversely, how does wisdom relate to ignorance? it says that the two truths are distinct in the sense that they are incompatible with unity, like entity and without entity. in the ultimate sense


the question now arises : how is ignorance related to wisdom? or conversely, how does wisdom relate to ignorance? it says that the two truths are distinct in the sense that they are incompatible with unity, like entity and without entity. in the ultimate sense, it argues, the two truths transcend identity and difference. ( gorampa, 1969a : 376d ) the transcendence of identity and difference from the ultimate standpoint is synonymous with the transcendence of identity and difference from the purview of the meditative equipoise of noble beings. however, from the conventional standpoint, it claims that the two truths are distinct in the sense that they are incompatible with their unity. it likens this relationship to the one between entity and without entity. ( gorampa, 1969a : 377a ) sakya ' s claim that the two truths are distinct and incompatible encompasses both ontological and epistemological distinctions. since what is divided into the two truths is mere mind, it is obvious that there is no single phenomenon that could serve as the objective referent for both. this also means that the two truths must be construed as corresponding to distinct spheres belonging to distinct modes of consciousness : conventional truth corresponds to ignorance and ultimate truth to wisdom. it is thus inappropriate to describe the relationship between the two truths, and their corresponding modes of consciousness, in terms of two ways of perceiving the same entity. although the two truths can be thought of as two ways of perceiving, one based on ignorance and the other on wisdom, there is no same entity perceived by both. there is nothing common between the two truths, and if they are both ways of perceiving, then they do not perceive the same thing. according to this view, the relationship between conventional truth and ultimate truth is analogous to the relationship between the appearance of falling hairs when vision is impaired by cataracts and the absence of such hairs when vision is unimpaired. although this is a metaphor, it has a direct application to determining the relationship between the two truths. conventional truth is like seeing falling hairs as a result of cataracts : both conventional truth and such false seeing are illusory, in the ontological sense that there is nothing to which each corresponds, and in the epistemological sense that there is no true knowledge in either case. ultimate truth is therefore analogous, ontologically and epistemologically, to the true seeing unimpaired by cataracts and


“ objects of knowledge ” ( shes bya ) are the basis for dividing the two truths. ( tsongkhapa 1984b : 176 ) this means that the two truths relate to “ two objects of knowledge, ” the idea it takes from the statement of the buddha from discourse on meeting of the father and the son ( pitaputrasamagama sutra ) by object of knowledge gelug means an object that is cognizable ( blo ' i yul du bya rung ba ). it must be an object of cognitive processes in general ranging from those of ordinary sentient beings through to those of enlightened beings. this definition attempts to capture any thing knowable in the broadest possible sense. since the buddha maintains knowledge of the two truths to be necessary for awakening, the understanding of the two truths must constitute an exhaustive understanding of all objects of knowledge. gelug ' s key argument to support this claim comes from its two - nature theory in which it has been argued that every nominally ( tha snyad ) or conventionally ( kun rdzob ) given phenomenon possesses dual natures : namely, the nominal ( or conventional nature ) and the ultimate nature. the conventional nature is unreal and deceptive while the ultimate nature is real and nondeceptive. since two natures pertain to every phenomenon, the division of the two truths means the division of each entity into two natures. thus the division of the two truths, “ reveals that it makes sense to divide even the nature of a single entity, like a sprout, into dual natures — its conventional and its ultimate natures. it does not however show, ” as non - gelug schools have it, “ that the one nature of the sprout is itself divided into two truths in relation to ordinary beings ( so skye ) and to noble beings ( aryas ). ” ( tsongkhapa 1984b : 173, 1992 : 406 ) the relation of the two truths comes down to the way in which the single entity appears to cognitive processes — deceptively and nondeceptively. the two natures correspond to these deceptive or nondeceptive modes of appearance. while they both belong to the same ontological entity, they are epistemically or conceptually mutually exclusive. take a sprout for instance. if it exists, it necessarily exhibits a dual nature, and yet those two natures cannot be ontologically distinct. the ultimate nature of the sprout cannot be separate from


or conceptually mutually exclusive. take a sprout for instance. if it exists, it necessarily exhibits a dual nature, and yet those two natures cannot be ontologically distinct. the ultimate nature of the sprout cannot be separate from its conventional nature — its color, texture, shape, extension, and so on. as an object of knowledge, the sprout retains its single ontological basis, but it is known through its two natures. these two natures exclude one another so far as knowledge is concerned. the cognitive process that knows the deceptive conventional nature of the sprout does not have direct access to its nondeceptive ultimate nature. similarly, the cognitive process that apprehends the nondeceptive ultimate nature of the sprout does not have direct access to its deceptive conventional nature. in newland ' s words : “ a table and its emptiness are a single entity. when an ordinary conventional mind takes a table as its object of observation, it sees a table. when a mind of ultimate analysis searches for the table, it finds the emptiness of the table. hence, the two truths are posited in relation to a single entity by way of the perspectives of the observing consciousness. this is as close as ge - luk - bas will come to defining the two truths as perspectives. ” ( 1992 : 49 ) gelug ' s two - nature theory not only serves as the basic reference point for its exposition of the basis of the division of the two truths, their meanings and definitions, but also serves as the basic ontological reference for its account of the relationship between the two truths. therefore gelug proposes the view that the two truths are of single entity with distinct conceptual identities. this view is also founded on the theory of the two natures. but how are the two natures related? are they identical or distinct? for gelug argues that there are only two possibilities : either the two natures are identical ( ngo bo gcig ) or distinct ( ngo bo tha dad ) ; there cannot be a third. ( tsongkhapa 1984b : 176 ) they are related in terms of being a single entity with distinct conceptual identities — thus they are both the same and different. since the two natures are the basis of the relationship between the two truths, the relationship between the two truths will reflect the relationship between the two natures. just as the two natures are of a same entity, ultimate truth and conventional truth are of same ontological status. gelug


“ matter itself is void. voidness does not result from the destruction of matter, but the nature of matter is itself voidness. ” ( vimalakirti, 1991 : 74 ) the same principle applies in the case of consciousness and the emptiness of consciousness, as well as to the rest of the five psychophysical aggregates — the aggregate and its emptiness are not causally related. for the causal relationship would imply either the aggregate is the cause, therefore its emptiness is the result, or the aggregate is the result, and its emptiness the cause. this would imply, according to gelug ' s reading, either the aggregate or the emptiness is temporally prior to its counterpart, thus leading to the conlusion that the conventional truth and ultimate truth exist independently of each other. such a view is for gelug is completely unacceptable. the ontological identity between being conditioned and being impermanent does not imply identity in all and every respect. insofar as their epistemic mode is concerned, conditioned and impermanent phenomena are distinct and contrasting. the concept impermanence always presents itself to the cognizing mind as momentary instants, but not as conditioned. similarly, the concept being - conditioned always presents itself to its cognizing mind as constituted by manifold momentary instants, but not as moments. thus it does not necessarily follow that the two truths are identical in every respect just because they share a common ontological identity. where the modes of conceptual appearance are concerned, ultimate nature and conventional nature are distinct. the conceptual mode of appearance of ultimate truth is nondeceptive and consistent with its mode of existence, while that of conceptual mode of conventional truth is deceptive and inconsistent with its mode of existence. conventional truth is uncritically confirmed by conventionally reliable cognitive process, whereas ultimate truth is critically confirmed by ultimately reliable cognitive process. hence, just as ultimate truth is inaccessible to the conventionally reliable cognitive process for its uncritical mode of engagement, so, too, is conventional truth inaccessible to ultimately reliable cognitive process for its critical mode of engagement. this is how, in gelug ' s view, the truths differ conceptually despite sharing a common ontological entity. in summarizing gelug ' s argument, khedrub je writes : “ the two truths are therefore of the same nature, but different conceptual identities. they have a single - nature relationship such that, if one did not exist, neither could the other, just like being conditioned and impermanent. ” ( 1992 : 364 ) the


any thing that dependently arises from them also changes. thus the appearance avoids the realism. the latter makes sense because the empty phenomena arises from causal conditions, and whatever arise from the causal conditions is not a non - existent, even though it lacks intrinsic reality. only when the causal conditions are satisfied do we see arising of the empty phenomena. hence by understanding that the empty phenomenon itself is causally efficient, the bearer of cause and effect, one is not robbed by the extreme view of nihilism. ( 1985 : 252 ) the argument for the unity of the two truths also takes epistemological form which also rests on the idea that emptiness and dependently arising are unified. the knowledge of empty phenomena is conceptually interlinked with that of dependently arisen phenomena — the latter is, in fact, founded on the former. to the extent that empty phenomena are understood in terms of relational and dependently arisen phenomena, to that extent empty phenomena are always functional and causally effective. the phrase “ empty phenomena, ” although expressed negatively, is not negative in a metaphysical sense — it is not equivalent to no - thingness. although the empty phenomenon appears to its cognizing consciousness negatively and without any positive affirmation, it is nonetheless equivalent to a relational and dependently arisen phenomenon seen deconstructively. since seeing phenomena as empty does not violate the inevitable epistemic link with the understanding of phenomena as dependently arisen, and the converse also applies, so the unity between the two truths — understanding things both as empty and as dependently arisen — is still sustained. the unity between the two truths, according to gelug, does not apply merely to ontological and epistemological issues ; it applies equally to soteriology — the practical means to the freedom from suffering. as jamyang shepai dorje argues that undermining either of the two truths would result in a similar downfall — a similar eventual ruin. if, however, they are not undermined, the two are alike insofar as the accomplishment of the two accumulations and the attainment of the two awakened bodies ( kayas ), and so forth, are concerned. if one undermines conventional truth or denies it ' s reality, one would succumb to the extreme of nihilism, which would also undermine the fruit and the means by which an awakened physical body ( rupakaya ) is accomplished. it is therefore not sensible to approach the two truths with bias. since this relation continues as


case of discussions about the ultimate nature of things, such as the being of the sprout — it only makes sense inasmuch as it holds in discussions of ordinary phenomena. the only criterion that determines a thing ' s truth in the prasangika madhyamaka system, according to gelug, is the causal effectiveness of the thing as opposed to mere heuristic significance. the sprout ' s empty mode of being and its being as appearance are both truths, insofar as both are causally effective, and thus both functional. the two truths, understood as, respectively, the empty and the dependently arisen characters of phenomena, are on equal footing according to gelug. nevertheless these truths have different designations — the sprout ' s empty mode is always described as “ ultimate truth, ” while the conventional properties, such as color and shape, are described as “ conventional truths. ” the former is accepted as nondeceptive truth while the sprout ' s conventional properties are accepted as deceptive or false truth, despite common sense dictating that they are true and real. in conclusion gelug ' s theory of the two truths is based on one fundamental thesis that each conventionally real phenomenon satisfies the definitions of both truths for each phenomenon, as it sees it, possesses two natures that serve as the basis of the definitions of the two truths. the two truths are conceptual distinctions applied to a particular conventionally real phenomenon, and every conventionally real phenomenon fulfills the criterion of both truths because each phenomenon constitutes these two natures they are not merely one specific nature of a phenomenon mirrored in two different perspectives. as each phenomenon possesses two natures, so each verifying cognitive process has a different nature as its referent, even though there is only one ontological entity and one cognitive agent involved. gelug considers the two natures of each phenomenon as the defining factor of the two truths. it argues that the conventional nature of an entity, as verified by a conventionally reliable cognitive process, determines the defining criterion of conventional truth ; the ultimate nature of the same entity, as verified by an ultimately reliable cognitive practice, determines the defining criterion of ultimate truth. since both truths are ontologically as well as epistemologically interdependent, knowledge of conventionally real entitity as dependently arisen suffices for knowledge of both truths. in contasty non - gelug schools — nyingma, kagyu and sakya non - gelug


science fair project encyclopedia | name, symbol, number | | selenium, se, 34 | | group, period, block | | 16 ( via ), 4, p | | density, hardness | | 4790 kg / m3 ( 300k ), 2 | | appearance | | grey, metallic lustre | | atomic weight | | 78. 96 amu | | atomic radius ( calc. ) | | 115 ( 103 ) pm | | covalent radius | | 116 pm | | van der waals radius | | 190 pm | | e - ' s per energy level | | 2, 8, 18, 6 | | oxidation states ( oxide ) | | ±2, 4, 6 ( strong acid ) | | state of matter | | solid ( _ _ ) | | melting point | | 494 k ( 430 °f ) | | boiling point | | 957. 8 k ( 1265 °f ) | | molar volume | | 16. 42 ×10 - 6 m3 / mol | | heat of vaporization | | 26. 3 kj / mol | | heat of fusion | | 6. 694 kj / mol | | vapor pressure | | 0. 695 pa at 494 k | | speed of sound | | 3350 m / s at 293. 15 k | | electronegativity | | 2. 48 ( pauling scale ) | | specific heat capacity | | 320 j / ( kg * k ) | | electrical conductivity | | 1. 0e - 10 106 / ( m · ohm ) | | thermal conductivity | | 2. 04 w / ( m * k ) | | 1st ionization potential | | 941 kj / mol | | 2nd ionization potential | | 2045 kj / mol | | 3rd ionization potential | | 2973. 7 kj / mol | | 4th ionization potential | | 4144 kj / mol | | most stable isotopes | | si units & stp are used except where noted. | selenium is a chemical element in the periodic table that has the symbol se and atomic number 34. this is a toxic nonmetal that is chemically related to sulfur and tellurium. it occurs in several different forms but one of these is a stable gray metallike form that conducts electricity better in the light than in the dark and is used in photocells. this element is found in sulfide ores such as pyrite


( tele, far, and pathein, to experience ) a term introduced by f. w. h. myers in 1882 to denote " the ability of one mind to impress or to be impressed by another mind otherwise than through the recognized channels of sense " ( gurney, " phantasms of the living ", i, 6 ) ; or : " the communication of impressions of any kind from one mind to another independently of the recognized channels of sense " ( myers, " human personality ", i, xxi ). the term telepathy is sometimes used, in conformity with its derivation, to mean the direct communication between minds at a great distance. such terms as thought - transference, mind - reading, or mental suggestion would then apply to the direct communication between minds in the same room or at a small distance. generally, however, at least in english, telepathy connotes only the exclusion of the recognized channels of sensation, irrespective of the distance. it supposes that, in some cases, the usual signs by which ideas are manifested —, writing, gestures, muscular contraction, facial expression, etc. — be dispensed with and that minds are able to communicate, if not directly and immediately, at any rate through some medium which is distinct from the ordinary medium of sense - perception. thus understood, telepathy includes two classes of facts. a. intentional communications the first class consists of intentional communications, when a person ( the agent ) by the concentration of his mind on some object makes an effort to transfer an idea to another person ( the percipient ) who may or may not be aware of the attempt, and who may or may not make an effort to receive the communication. the experiments, made sometimes on normal more generally and more successfully on hypnotized subjects, include the transference of tastes, sounds, visual images, pain etc. ; the guessing of numbers, cards, colours, diagrams etc., thought of by the agent ; the execution or inhibition of movements in compliance with the agent ' s will ; the production or cessation of the hypnotic condition at a command mentally given ; and other similar transferences of thought. in a few successful instances the agent has been able to produce apparitions of himself or even of a third person to the percipient in another room or house. in these experiments the main difficulty is to make sure that the percipient in no way uses his senses, which are in a state of hyperæ


himself or even of a third person to the percipient in another room or house. in these experiments the main difficulty is to make sure that the percipient in no way uses his senses, which are in a state of hyperæsthesia or extraordinary acuteness, and that the correct guesses cannot be accounted for by similar habits, suggestions, and associations in both the agent and the percipient. exhibitions of so - called mind - reading are generally explainable either by clever collusion, or by muscle - reading when there is contact between the agent and the percipient, or by the interpretation of sensory indications consciously or unconsciously given. b. spontaneous communications the other class of facts consists of spontaneous communications in which, as far as we can know, the agent has no intention of manifesting himself to the percipient. herein are included especially the intimation of the danger, illness, distress, or death of some person, generally a friend or relative, and the apparition of the phantasm of such a person especially at the time of his death ; the degree of precision and exactness of these monitions varies indefinitely. sometimes they consist in a merely physical occurrence coincident with the death, such as noise, the fall of some object, of a picture, etc. sometimes ill - defined and inexplicable feelings of restlessness and uneasiness are experienced, or the sudden idea of what is happening flashes across the mind. sometimes finally, either in the waking state or in dreams, apparitions are seen, and even entire scenes witnessed in all their details. the main difficulty in these cases is to determine whether they present mere coincidences due to subjective factors, such as habit association, memory, expectation etc., or a real causality. two problems are to be solved regarding telepathy : a. is the existence of telepathy as a fact demonstrated? b. if it is, what is its explanation? a. is the fact of telepathy established? is the fact of telepathy established? in the past thirty or forty years, this subject has been studied critically. a large number of facts have been collected, especially by the society for psychical research, founded in 1882, and have been published in " phantasms of the living ", the " proceedings " of the society, and many other works. in france, the " annales des sciences psychiques " also record numerous cases. at present the


new materials for sustainable energy professor david s. sholl holds the michael e. tennenbaum family chair and is the gra eminent scholar for energy sustainability. his research vision is to develop new materials and processes that contribute to sustainable energy use on relevant global scales : gigawatts of energy and gigatons of reductions in carbon emissions. sholl ’ s research uses computational materials modeling to develop new materials for energy storage and generation. the aim of using theoretical tools in this area is to accelerate experimental progress on problems where the search space of materials contains thousands or millions of possibilities. by working with a wide range of experimental partners in academia and industry, the sholl research group is helping to develop practical solutions to the immense energy - related challenges that will confront our global society for decades to come. his group has already developed quantitatively accurate computational methods that predict the suitability of millions of hydride mixtures for hydrogen storage in vehicles powered by fuel cells. groups around the world are now testing many of these materials experimentally. now, sholl is turning his attention to other pressing energy issues. his group is developing similar methods to screen the enormous number of metal alloys that can be considered as membranes for purifying hydrogen, as well as screening methods for nanoporous materials that can be used as membranes to purify gas mixtures involving carbon dioxide. by using innovative modeling tools and sensors ( like the one depicted below ), the sholl group is able to more quickly identify the best materials for use in new metal - organic framework membranes now under development.


to use all functions of this page, please activate cookies in your browser. with an accout for my. chemeurope. com you can always see everything at a glance – and you can configure your own website and individual newsletter. - my watch list - my saved searches - my saved topics - my newsletter strontium ( pronounced / ˈstrɒntiəm / ) is a chemical element with the symbol sr and the atomic number 38. an alkaline earth metal, strontium is a soft silver - white or yellowish metallic element that is highly reactive chemically. the metal turns yellow when exposed to air. it occurs naturally in the minerals celestine and strontianite. the 90sr isotope is present in radioactive fallout and has a half - life of 28. 90 years. strontium is a bright silvery metal that is softer than calcium and even more reactive in water, which strontium decomposes on contact with to produce strontium hydroxide and hydrogen gas. it burns in air to produce both strontium oxide and strontium nitride, but since it does not react with nitrogen below 380°c it will only form the oxide spontaneously at room temperature. it should be kept under kerosene to prevent oxidation ; freshly exposed strontium metal rapidly turns a yellowish color with the formation of the oxide. finely powered strontium metal will ignite spontaneously in air. volatile strontium salts impart a crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. natural strontium is a mixture of four stable isotopes. as a pure metal strontium is being used in strontium 90 % - aluminium 10 % alloys of an eutectic composition for the modification of aluminium - silicon casting alloys. the primary use for strontium compounds is in glass for colour television cathode ray tubes to prevent x - ray emission. 87sr / 86sr ratios are commonly used to determine the likely provenance areas of sediment in natural systems, especially in marine and fluvial environments. dasch ( 1969 ) showed that surface sediments of the deep atlantic displayed 87sr / 86sr ratios that could be regarded as bulk averages of the 87sr / 86sr ratios of geological terranes from adjacent landmasses. one good example of a fluvial system to which sr isotope ratio studies have been frequently employed is the river nile ( krom et al, 1999 ; krom et al,


coherent theoretical explanation. " review 5. " my feeling is that there should be no funds set aside for support of cf research but, if the doe receives a proposal in this area which suggests some definitive research which settle some of the issues, it should consider it for support as it would any other proposal. " review 6. " i find nothing in the articles that i ' ve read that convinces me that the new anomalies reported are not experimental artifacts. " review 7. " i find in summary that, even after all of the work that has been done, the case is spotty for the existence of the cold fusion phenomenon. i am not convinced by the evidence that i have seen... " review 8. " if the bottom line is that experiments in which x > 0. 95 in pddx ( at room temperature ) give anomalous effects reliably ( even if achieving that high x is very difficult and very dependent on the materials science of the pd ), while heat balance is attained for x < 0. 9 in pddx ( or when using pdhx at all x ), we ' ve got the start of science. " review 9. " evidence for excess heat in lenr experiments is compelling and well established.... the body of work that has resulted from lenr investigations is formidable and worthy of attention of the broader scientific community. it is unfortunate that a few vocal individuals have manage to stigmatize this field and those working in it. " review 10. " in a general summary of the calorimetric results, the observation of sudden and prolonged temperature excursions..., has been made a sufficient number of times that, even if not totally reproducible, still have not been explained in terms of conventional chemistry or electrochemistry... at this stage, i think the evidence suggests the possibility of such events, [ but ] cannot be considered conclusive beyond a reasonable doubt, for reasons alluded to above. " review 11. " the care in which the measurements are done for experiments that do show excess heat are convincing evidence of low energy nuclear reactions.... there is strong evidence of nuclear reactions in palladium, and suggestions of reactions in the titanium foil experiments. " review 12. " there seem to be increasing evidence for the production of excess heat, even though the reason is totally unknown.... yes, it is likely that an unknown process ( in materials physics or in nuclear physics ) is responsible. however, the link to nuclear


seem to be increasing evidence for the production of excess heat, even though the reason is totally unknown.... yes, it is likely that an unknown process ( in materials physics or in nuclear physics ) is responsible. however, the link to nuclear reaction is still not strong enough at the present time.... the current evidence is not sufficiently conclusive to demonstrate that nuclear reactions occur in metal deuterides yet. " review 13. "... there is sufficient evidence to demonstrate that very low energy nuclear reactions can occur in condensed matter at rates that are totally unexpected " review 14. " i am not persuaded that such energy has been produced. " review 15. " as one of the reviewers stated, one can never disprove something and this is my feeling about " cold fusion ". " review 16. " my opinion is that none of the experimental evidence directly presented to us is conclusive that nuclear reactions are occurring in these environments, but some of the evidence is certainly suggestive that they are. " review 17. " most " nuclear " measurements ( particle emission ) are not convincing in comparison with the state of the art in low energy nuclear physics. " review 18. " although experiments have become more sophisticated there is no new convincing or even tantalizing evidence for lenr. " edited by johnfolton, : edited to clarify that the doe scientists were not creationists but an unbiased appraisal of 15 years of cold fusion research. i note that you provide no evidence that anyone claims that cold fusion is responsible for the production of c14 within the earth. jazzns claimed message 6 : c14 is not just produced in the atmosphere. it is also produced by normal radioactive decay of elements in the ground. johnfolton responded : c14 has only been proven to be formed in the upper atmosphere. we have reputable scientists ( not creationists ) of the department of energy who reviewed 15 years of cold fusion experiments and concluded the coulomb barrier to great to be overcome by cold fusion by the normal conditions within the earth. n14 needs a neutron to become c14 this is an example of fusion not fission. 1n + 14n = 14c + 1p i agree in advance that their is no such thing as cold fusion within the earth and we all likely also agree 15n is converting to 14c in the upper atmosphere due to a neutron being accepted and the emission of a proton. you don ' t see a neutron being emitted as in fission. nuclear fission : basics when a nucleus


by a nanoparticle composed of nickel and phosphorus, two inexpensive elements that are abundant on earth.... the fraunhofer institute for laser technology ilt generated a lot of interest at the laser world of photonics 2013 trade fair with its numerous industrial laser technology innovations. its highlights included beam sources and manufacturing processes for ultrashort laser pulses as well as ways to systematically optimize machining processes using computer simulations. there was even a specialist booth at the fair dedicated to the revolutionary technological potential of digital photonic production. now in its fortieth year, laser world... it ' s not reruns of " the jetsons ", but researchers working at the national institute of standards and technology ( nist ) have developed a new microscopy technique that uses a process similar to how an old tube television produces a picture — cathodoluminescence — to image nanoscale features. combining the best features of optical and scanning electron microscopy, the fast, versatile, and high - resolution technique allows scientists to view surface and subsurface features potentially as small as 10 nanometers in size. the new microscopy technique, described in the journal aip advances, * uses a beam of electrons to excite a specially... 18. 06. 2013 | materials sciences 18. 06. 2013 | health and medicine 18. 06. 2013 | life sciences 14. 06. 2013 | event news 13. 06. 2013 | event news 10. 06. 2013 | event news


publisher : prentice hall ptr in recent years, with the explosion of web - based applications and the ever - growing popularity of the java programming language and related java based technologies, there has been an increasing number of vendors offering middle - tier products on which developers could build and deploy applications. this major shift from two - tier client - server paradigm to n - tier architecture brings many challenges, especially in the area of system security. to learn about how to secure your j2ee applications, read on. about the author pankaj kumar is a software architect at hp ' s web services management organization and has worked extensively in the area of middleware and security. he has presented on java and web services technologist events ranging from sd west and sd forum to hp world. inside the book this book is organized into three main parts. part one is all about basic security and the java platform. part two introduces the readers to the basic building blocks of the java platform ' s security architecture - apis for cryptographic operations, pki infrastructure, access control mechanisms, java secure socket extensions, and apis for xml. and finally, the third and final part links together the concepts introduced in part two. the first part of the book kicks off with a look at news reports and case studies to get a feel for computer and network security problems. the first chapter ends with brief description of how to enable technologies in the fight against computer crime and how application security fits into the overall scheme of things. what follows is an overview on the java platform, consisting of j2se and j2ee, with focus on security aspects. the second part of the book starts with an explanation of cryptographic services and the java api supporting these services. basic cryptographic apis ( jca and jce ) are covered. here you learn about the secret key and pk cryptography, message digests, message authentication code, and digital signature. the following chapter discusses java support for pki components such as x. 509 certificates, certification authorities, and certificate revocation lists. next, you encounter an explanation of the security model used to protect resources within jvm with a security manager. we continue by going deeper into security with chapter six that explains ssl also known as transport layer security, protocol for securing exchange of information over unprotected networks at the transport level. in last chapter in the second part of the book the author writes about message security as a means to secure messages independent of transport. xml security standards xml signature and xml encryption are explained. this


| bulk modulus | | 7. 7 gpa | | cas registry number | | 7704 - 34 - 9 | sulfur or sulphur ( pronounced / /, see spelling below ) is the chemical element that has the atomic number 16. it is denoted with the symbol s. it is an abundant multivalent non - metal. sulfur, in its native form, is a yellow crystalline solid. in nature, it can be found as the pure element and as sulfide and sulfate minerals. it is an essential element for life and is found in two amino acids, cysteine and methionine. its commercial uses are primarily in fertilizers, but it is also widely used in gunpowder, matches, insecticides and fungicides. elemental sulfur crystals are commonly sought after by mineral collectors for their brightly colored polyhedron shapes. in nonscientific context it can also be referred to as brimstone. english translations of the bible commonly referred to sulfur as " brimstone ", giving rise to the name of ' fire and brimstone ' sermons, in which listeners are reminded of the fate of eternal damnation that awaits the unbelieving and unrepentant. it is from this part of the bible that hell is implied to " smell of sulfur ", although as mentioned above sulfur is in fact odorless. the " smell of sulfur " usually refers to either the odour of hydrogen sulfide, e. g. from rotten egg, or of burning sulfur, which produces sulfur dioxide, the smell associated with burnt matches. sulfur was known in china since the 6th century bc, in a natural form that the chinese had called ' brimstone ', or shiliuhuang that was found in hanzhong. by the 3rd century, the chinese discovered that sulfur could be extracted from pyrite. chinese daoists were interested in sulfur ' s flammability and its reactivity with certain metals, yet its earliest practical uses were found in traditional chinese medicine. a song dynasty military treatise of 1044 ad described different formulas for chinese gun powder, which is a mixture of potassium nitrate ( kno3 ), carbon, and sulfur. early alchemists gave sulfur its own alchemical symbol which was a triangle at the top of a cross. in 1777 antoine lavoisier helped convince the scientific community that sulfur was an element and not a compound. in 1867, sulfur was discovered in underground deposits in louisiana and texas. the overlying layer of earth was


at the top of a cross. in 1777 antoine lavoisier helped convince the scientific community that sulfur was an element and not a compound. in 1867, sulfur was discovered in underground deposits in louisiana and texas. the overlying layer of earth was quicksand, prohibiting ordinary mining operations, therefore the frasch process was used. spelling and etymology the element has traditionally been spelled sulphur in the united kingdom, ireland, hong kong, the commonwealth caribbean and india, but sulfur in the united states, while both spellings are used in australia, new zealand and canada. iupac adopted the spelling “ sulfur ” in 1990, as did the royal society of chemistry nomenclature committee in 1992 and the qualifications and curriculum authority for england and wales recommended its use in 2000. in latin, the word is variously written sulpur, sulphur, and sulfur ( the oxford latin dictionary lists the spellings in this order ). it is an original latin name and not a classical greek loan, so the ph variant does not denote the greek letter φ. sulfur in greek is thion ( θειον ), whence comes the prefix thio -. the simplification of the latin word ' s p or ph to an f appears to have taken place towards the end of the classical period, with the f spelling becoming dominant in the medieval period. at room temperature, sulfur is a soft bright yellow solid. elemental sulfur has only a faint odour, similar to that of matches. the odour associated with rotten eggs is due to hydrogen sulfide ( h2s ) and organic sulfur compounds rather than elemental sulfur. sulfur burns with a blue flame that emits sulfur dioxide, notable for its peculiar suffocating odour. sulfur is insoluble in water but soluble in carbon disulfide and to a lesser extent in other non - polar organic solvents such as benzene and toluene. common oxidation states of sulfur include −2, + 2, + 4 and + 6. sulfur forms stable compounds with all elements except the noble gases. sulfur in the solid state ordinarily exists as cyclic crown - shaped s8 molecules. the crystallography of sulfur is complex. depending on the specific conditions, the sulfur allotropes form several distinct crystal structures, with rhombic and monoclinic s8 best known. a noteworthy property of sulfur is that its viscosity in its molten state, unlike most other liquids, increases above temperatures of 200 °c due to the formation of polymers


crystal structures, with rhombic and monoclinic s8 best known. a noteworthy property of sulfur is that its viscosity in its molten state, unlike most other liquids, increases above temperatures of 200 °c due to the formation of polymers. the molten sulfur assumes a dark red colour above this temperature. at higher temperatures, however, the viscosity is decreased as depolymerization occurs. amorphous or " plastic " sulfur can be produced through the rapid cooling of molten sulfur. x - ray crystallography studies show that the amorphous form may have a helical structure with eight atoms per turn. this form is metastable at room temperature and gradually reverts back to crystalline form. this process happens within a matter of hours to days but can be rapidly catalyzed. sulfur forms more than 30 solid allotropes, more than any other element. besides s8, several other rings are known. removing one atom from the crown gives s7, which is more deeply yellow than s8. hplc analysis of " elemental sulfur " reveals an equilibrium mixture of mainly s8, but also s7 and small amounts of s6. larger rings have been prepared, including s12 and s18. by contrast, sulfur ' s lighter neighbour oxygen only exists in two states of allotropic significance : o2 and o3. selenium, the heavier analogue of sulfur can form rings but is more often found as a polymer chain. sulfur has 18 isotopes, four of which are stable : 32s ( 95. 02 % ), 33s ( 0. 75 % ), 34s ( 4. 21 % ), and 36s ( 0. 02 % ). other than 35s, the radioactive isotopes of sulfur are all short lived. 35s is formed from cosmic ray spallation of 40argon in the atmosphere. it has a half - life of 87 days. when sulfide minerals are precipitated, isotopic equilibration among solids and liquid may cause small differences in the δs - 34 values of co - genetic minerals. the differences between minerals can be used to estimate the temperature of equilibration. the δc - 13 and δs - 34 of coexisting carbonates and sulfides can be used to determine the ph and oxygen fugacity of the ore - bearing fluid during ore formation. in most forest ecosystems, sulfate is derived mostly from the atmosphere ; weathering of ore minerals and evapor


matter. the distinctive colors of jupiter ' s volcanic moon, io, are from various forms of molten, solid and gaseous sulfur. there is also a dark area near the lunar crater aristarchus that may be a sulfur deposit. sulfur is present in many types of meteorites. ordinary chondrites contain on average 2. 1 % sulfur, and carbonaceous chondrites may contain as much as 6. 6 %. sulfur in meteorites is normally present entirely as troilite ( fes ), but other sulfides are found in some meteorites, and carbonaceous chondrites contain free sulfur, sulfates, and possibly other sulfur compounds. extraction and production production from hydrogen sulfide the claus process is used to extract elemental sulfur from hydrogen sulfide produced in hydrodesulfurization of petroleum or from natural gas. in the biological route, h2s from natural gas or refinery gas is absorbed with a slight alkaline solution in a wet scrubber. or the sulfide is produced by biological sulfate reduction. in the subsequent process step, the dissolved sulfide is biologically converted to elemental sulfur. this solid sulfur is removed from the reactor. this process has been built on commercial scale. the main advantages of this process are 1 ) no use of expensive chemicals, 2 ) the process is safe as the h2s is directly absorbed in an alkaline solution, 3 ) no production of a polluted waste stream, 4 ) re - usable sulfur is produced, and 5 ) the process occurs under ambient conditions. the biosulfur product is different from other processes in which sulfur is produced because the sulfur is hydrophillic. next to straightforward reuses as source for sulfuric acid production, it can also be applied as sulfur fertilizer. hydrogen sulfide has the characteristic smell of rotten eggs. dissolved in water, hydrogen sulfide is acidic and will react with metals to form a series of metal sulfides. natural metal sulfides are common, especially those of iron. iron sulfide is called pyrite, the so - called fool ' s gold. pyrite can show semiconductor properties. galena, a naturally occurring lead sulfide, was the first semiconductor discovered, and found a use as a signal rectifier in the " cat ' s whiskers " of early crystal radios. many of the unpleasant odours of organic matter are based on sulfur - containing compounds such as methyl and ethyl mercaptan, also used to scent natural gas so that leaks are


a cave is a natural underground void large enough for a human to enter. some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight ; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and grottos. speleology is the science of exploration and study of all aspects of caves. exploring a cave for recreation or science may be called caving, potholing, or, in canada and the united states, spelunking ( see caving ). types and formation the formation and development of caves is known as speleogenesis. caves are formed by various geologic processes. these may involve a combination of chemical processes, erosion from water, tectonic forces, microorganisms, pressure, atmospheric influences, and even digging most caves are formed in limestone by dissolution. - solutional caves may form anywhere with rock that is soluble, and are most prevalent in limestone, but can also form in other material, including chalk, dolomite, marble, granite, salt, sandstone, fossilized coral and gypsum. - the largest and most abundant solutional caves are located in limestone. limestone dissolves under the action of rainwater and groundwater charged with h2co3 ( carbonic acid ) and naturally occurring organic acids. the dissolution process produces a distinctive landform known as karst, characterized by sinkholes, sinking streams, and underground drainage. limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. this include : flowstones, stalactites, stalagmites, helictites, draperies, soda straws and columns. these secondary mineral deposits in caves are called speleothems. - the world ' s most spectacularly decorated cave is generally regarded to be lechuguilla cave in new mexico. lechuguilla and nearby carlsbad caverns are now believed to be examples of another type of solutional cave. they were formed by h2s ( hydrogen sulfide ) gas rising from below, where reservoirs of oil give off sulfurous fumes. this gas mixes with ground water and forms h2so4 ( sulfuric acid ). the acid then dissolves the limestone from below, rather than from above, by acidic water percolating from the surface. - some caves are formed at the same time as the surrounding rock. these are sometimes called primary caves. - lava tubes are formed through volcanic activity and are the most common ' primary '


" electronegativity is the power of an atom when in a molecule to attract eletrons to itself. " the electronegativity will depend upon a number of factors including other atoms in the molecule, the number of atoms coordinated to it, and the oxidation number for the atom. there are a number of ways to produce a set of numbers which represent electronegativity scales. the pauling scale is perhaps the most famous. he noticed that the bond energy e ( ab ) in a molecule ab is always greater than the mean of the bond energies e ( aa ) + e ( bb ) in the homonuclear species aa and bb. his argument was that in an " ideal " covalent bond e ( ab ) should equal this mean, and that the " excess " bond energy is caused by electrostatic attraction between the partially charged atoms in the heternuclear species ab. in effect, he was saying that the excess bond energy arises from an ionic contribution to the bond. he managed to treat this ionic contribution by the equation e ( ab ) = [ e ( aa ). e ( bb ) ] 1 / 2 + 96. 48 ( χa - χb ) 2 in which e ( ab ) is expressed in kj mol - 1 ( 1 electron volt, 1ev, = 96. 48 kj mol - 1 ) and χa - χb represents the difference in " electronegativity " between the two elements, whose individual electronegativities are given the symbols χa and χ. using this equation, pauling found that the largest electronegativity difference was between cs and f. pauling set f arbitrarily at 4. 0 ( today, the value for f is set to 3. 98 ) and this gives a scale in which the values for all other elements are less than 4 but still with a positive number. most values are taken from reference 1 and where values are missing from reference 2. values for group 18 elements and for elements 95 - 102 are taken from reference 3. pauling electronegativities are published in many sources and essentially identical data are to be found in references such as 4 and 5. webelements now has an online chemistry shop at which you can buy periodic table posters, mugs, t - shirts, games, molecular models, and more.


logic devices from neuronal cultures ( to design a novel neuronal device click here ) neurons in the brain perform amazing calculations in a flash, but if you put them into a dish they become sluggish and ' stupid ' - i. e. their response repertoire is very limited. our principal question is how the connections between the neurons be manipulated so as to improve their computational capacity. in the current project, we used 1d cultures and took one step up the dimensionality scale to create " function - follows - structure " neuronal devices. for example the triangular diode alternates between one and two dimensional patterns to create an asymmetric connectivity between ensembles of neurons. the transmission of signals along a line that includes these devices is necessary if we want to measure the performance of our devices - this is how we are able to control their input, located in a defined area of the culture, and measure their output, located at a different area. nine separate neuronal devices patterned on a single 13mm coverslip ( 4 thresholds on the left column, 4 and gates on the center column and on the right a composite diode consisting of 8 daisy - chained triangles ). dark field illumination, bright areas are concentrations of neurons. neurontimelapse. wmv - hippocampal neurons growing on patternned glass coverslip ( field of view is centered on a connection between two triangles, see left figure ). in a few hours cell bodies send axons and connect between themselves. threshold two parallel straight lines connected with a thin line ( < 50µm ). here, input signals of population activity were observed at the right line and the resulting output signals were measured at the left line. only signals whose strength surpassed a limit propagated to the other side. a pair of straight lines served as inputs, interconnected at one end with a thick perpendicular line. at the other end they were connected via two thin lines to a central region serving as output. when the two input regions were disconnected ( via local application of ttx - red arrow ) they fired independently and no output response was observed ( 0 ^ 1 = 0, 1 ^ 0 = 0 ). when both input regions fired synchronously, the output region responded ( 1 ^ 1 = 1 ). a series of concatenated isosceles triangles, each one connected at its tip to the base of the consecutive triangle. the input and output was measured from two consecutive triangles. only signals that originated in the lower triangle propagate upwards


). a series of concatenated isosceles triangles, each one connected at its tip to the base of the consecutive triangle. the input and output was measured from two consecutive triangles. only signals that originated in the lower triangle propagate upwards while signals originating in the upper triangle are blocked when trying to propagate backwards. neuronal devices expressing gfp provide insight on how structure affects function. in the threshold ( left ) the thin section limit the number of axons that connect the lines. in the diode, the triangles funnel axons forward to the next triangle ( cyan tracks ) and backward crossings are less likely ( red tracks ). oscillatora neuronal oscillator can be assembled by combining diodes into a closed loop. usually, signals in a closed loop propagate in both directions and at a point of rendevouz both fronts " annihilate " due to the refractoriness property of bursts ( neurons have to " rest " between bursts ). here, the diodes determine a single direction of propagation and by the time a signal completes a cycle along the oscillator, the refractory period is over and the burstis free to repeat itself. in the movie ( oscillator. wmv ) the center region of the oscillator is imaged while a signal completes a single anti - clockwise loop. our primary goal is to understand how computation comes about from an ensemble of neurons. we believe that building these logic devices not only provides a methodology for precise monitor and control over neural networks but also insight on how they function. for example, the existence of a threshold level for activation turns out to play a central role in neuronal computation. we encounter this phenomenon for the case of neuronal ensembles and also in other, percolating neuronal network systems that we investigate in the lab.


investing in graphene just got another thumbs up. researchers at fudan university in china have just announced that a theoretical study of graphene has revealed the material ’ s suitability for the manufacture of spin switches. spin switches rely on magnetic spin properties rather than electric charge to produce the kind of “ valves ” used in such advanced applications as hard disk drive read heads. although it is not necessary to understand the science in order to make a well informed financial decision the news adds to the increasing number of research studies that suggest investing in graphene would be a prescient financial decision. the researchers found that graphene nanoribbons maximise the unique edge properties of graphene to produce spin polarization. their calculations show how the nanoribbons of two graphene islands form parallel and anti - parallel polarizations with respect to each other depending on the amount of energy passed across them. the spin anti - aligned islands do not pass electrons across them, whilst the spin aligned islands do ; such a clear mechanism of switching makes the graphene ideal for work in the emerging field of spintronics. in addition, news from japan suggests that researchers have found a way to produce a magnetism in graphene. the production of hydrogen terminated nanopores on a graphene sheet affects the spin value of the zigzag edges of the hioneycomb structure. the phenomenon occurs at room temperature and could one day be used to produce strong and light magnets and spintronic devices. sources : tokyo institute of tehnology.


( physorg. com ) - - scientists have used the nasa / esa hubble space telescope to observe a quasar accretion disc - - a glowing disc of matter that is slowly being sucked into its galaxy ' s central black hole. their study makes use of a novel technique that uses gravitational lensing to give an immense boost to the power of the telescope. the precision of the method has allowed astronomers to directly measure the disc ' s size and temperature across different parts of the disc. an international team of astronomers has used a new technique to study the bright disc of matter surrounding a faraway black hole. using the nasa / esa hubble space telescope, combined with the gravitational lensing effect of stars in a distant galaxy, the team measured the disc ' s size and studied the colours ( and hence the temperatures ) of different parts of the disc. these observations show a level of precision equivalent to spotting individual grains of sand on the surface of the moon. while black holes themselves are invisible, the forces they unleash cause some of the brightest phenomena in the universe. quasars short for quasi - stellar objects are glowing discs of matter that orbit supermassive black holes, heating up and emitting extremely bright radiation as they do so. " a quasar accretion disc has a typical size of a few light - days, or around 100 billion kilometres across, but they lie billions of light - years away. this means their apparent size when viewed from earth is so small that we will probably never have a telescope powerful enough to see their structure directly, " explains jose munoz, the lead scientist in this study. until now, the minute apparent size of quasars has meant that most of our knowledge of their inner structure has been based on theoretical extrapolations, rather than direct observations. the team therefore used an innovative method to study the quasar : using the stars in an intervening galaxy as a scanning microscope to probe features in the quasar ' s disc that would otherwise be far too small to see. as these stars move across the light from the quasar, gravitational effects amplify the light from different parts of the quasar, giving detailed colour information for a line that crosses through the accretion disc. the team observed a group of distant quasars that are gravitationally lensed by the chance alignment of other galaxies in the foreground, producing several images of the quasar. they spotted subtle differences in colour between the images, and changes in colour over the time the


thin film has ' astonishing ' ability to rotate light apr 4, 2011 5 comments physicists in austria and germany have taken the faraday effect to a new extreme by rotating the polarization of light by 45° by passing it through an extremely thin film. this " giant faraday effect " could someday be used to create optical transistors that switch light or to improve terahertz imaging systems. discovered in 1845 by michael faraday, the faraday effect describes how a magnetic field shifts the polarization of light as the light passes through a medium. a material ' s ability to rotate light is defined by its verdet constant – the amount of rotation given per tesla of magnetic field strength and per metre of material. the previous record for the strongest faraday effect was the semiconductor indium - antimony, which has a verdet constant of about 104 radians per tesla per metre. now andrei pimenov and colleagues at the vienna institute of technology in austria and the university of wurzburg have shown that mercury - telluride has a verdet constant of 106 radians per tesla per metre – which pimenov described as " astonishing ". a layered approach to investigate mercury - telluride ' s optical properties, the team layers the material over a thin piece of cadmium - telluride, which does not contribute to the faraday rotation. then linearly polarized light – with its electric - field electric component oscillating along a certain direction – is sent into the sample. the oscillating electric field causes conduction electrons in the material to drift to and fro. when a magnetic field is applied to the material, the electrons assume circular orbits. these orbits affect the speed at which right and left circularly polarized light travels through the material. this has the effect of rotating the direction of polarization. the researchers measured the effect by passing the emerging light through a polarizing filter – either aligned with the initial polarization or perpendicular to it. in the absence of the magnetic field, the aligned polarizer lets all the light through, while the perpendicular filter blocks it entirely. however, as the magnetic field is increased, less light comes through the aligned filter and more through the perpendicular filter. the proportion of transmitted light for each alignment told the researchers the degree to which the beam had turned. for the film with a thickness of just 70 nm, the rotation reached a maximum of about 15° with a magnetic field of 1 tesla. however, a layer of mercury telluride 1 µm thick


the degree to which the beam had turned. for the film with a thickness of just 70 nm, the rotation reached a maximum of about 15° with a magnetic field of 1 tesla. however, a layer of mercury telluride 1 µm thick could rotate the light a little more than 45°. sebastien francoeur of ecole polytechnique in montreal called the semiconductor an " intriguing material " because electrons can travel relatively long distances without scattering and the electrons low effective mass – they behave as if they have just a 30th of their actual masses. francoeur said these properties are " the special ingredients resulting in this giant magneto - optical effect ". the effective mass of the electrons and the strength of the magnetic field help define the cyclotron frequency of the circular orbits. when the rotation of the light is greatest, the cyclotron frequency matches that of the light, suggesting that this resonance contributes to the giant faraday effect. to put the effect to use, the researchers suggest a transistor design for optical computing. " using an external magnetic field, you can either switch on or switch off the transmission of the light, " says pimenov. while an electronic transistor decides whether to let a current pass depending on the voltage applied to it, a mercury - telluride layer between two aligned linear polarizers would let light through when the magnetic field was off but not when it was on. in order to make this device, the team would need to twist the light by 90° rather than just 45°. pimenov says that multiple layers of mercury - telluride, separated by cadmium - telluride, should be able to rotate light by 360° or more. with exactly 45° of rotation, the effect can also make for optical one - way valves. the light would pass through a linear polarizer and then be rotated by 45° on its way forward. if reflected, it would turn another 45° on its way back through the mercury - telluride. now aligned perpendicular to the polarizer, it couldn ' t pass. the effect could also be used to perform terahertz imaging and spectroscopy in molecular biology, medicine, and security. according to francoeur, terahertz light is " notoriously difficult to guide and it is challenging to manipulate its polarization state ". the giant faraday effect in mercury - telluride makes a welcome addition to the toolbox. the research is reported in phys. rev. lett. 106 107404


| a hollow - ion resonance of unprecedented strength | a so - called hollow ion is formed when core electrons are removed or excited to higher energy levels, leaving an empty inner shell. such states can be produced in he -, a fundamental three - electron system and prototypical negative ion. the nuclear coulomb attraction is efficiently screened in negative ions, greatly enhancing the effects that the electrons have on each other and providing an ideal opportunity to verify and further motivate theoretical models of electron correlation. our understanding of these basic interactions can elucidate processes of importance in many fields, from the interpretation of cosmic spectra to x - ray lasing efforts using inner - shell ionization and hollow - ion formation. at the ion - photon beamline at the als, researchers have detected in negative helium ions a resonant simultaneous double - auger decay of unprecedented strength, evidence of a triply excited hollow - ion state that has eluded observation for 25 years. in contrast to valence - electron excitations, decay pathways of core excited states are highly correlated phenomena, typically involving multi - electron processes such as auger decay. states located above the double - ionization limit ( such as triply excited hollow - ion states ) can decay via two - electron emission in a single step if one electron is demoted with the simultaneous emission of two others ( double - auger decay ). the significant challenges presented by these complex and exotic multi - electron processes to high - level theoretical models make detailed studies in computationally accessible three - electron prototype systems of prime interest. the first experimental investigation in he - indicated that some of the observed structure was inconsistent with predictions and stimulated renewed theoretical interest. included in these new ab initio calculations were detailed investigations of hollow - ion resonances. the positions, widths, and cross sections of these resonances present sensitive parameters for evaluating the calculations ; however, such measurements remained unavailable. in addition, while the lowest triply excited quartet state in he - ( the 2s2p2 4p state ) was predicted 25 years ago, until now it has eluded observation. in fact, this state has not been observed in photoexcitation of any three - electron system. at the ion - photon beamline at the als, researchers were able to measure, for the first time, the photoexcitation widths, line shapes, and absolute cross sections of he - triply excited ( hollow - ion ) states. a rubidium - vapor charge - exchange ion source was used to produce a 9. 96


the first time, the photoexcitation widths, line shapes, and absolute cross sections of he - triply excited ( hollow - ion ) states. a rubidium - vapor charge - exchange ion source was used to produce a 9. 96 - kev he - beam in the 1s2s2p 4po ground state. a 60 - na beam of he - was merged with a counter - propagating photon beam from als beamline 10. 0. 1, leading to excitation of the he - from its ground state to the 2s2p2 4p, 2p3s3p 4d, and 2p3s3p 4p states. subsequent auger decay in the merged region led to two - electron loss. the resulting he + ions ( the signal ) were deflected by a demerging magnetic field and counted to obtain the cross sections ( i. e., probabilities ) of the various resonances versus incident photon energy. because the 2s2p2 4p state lies below the 2s2 threshold, there is no intermediate state to accommodate sequential ( two - step ) auger decay. the observed signal must therefore be due to a double - auger process, involving all three electrons of the ion simultaneously. this represents the first observation of double - auger decay from a photoexcited negative ion, and its strength is three to four orders of magnitude larger than similar observations in other systems. calculations of double - auger decay in he - are not yet available and would be of great value in improving our understanding of this unexpectedly strong resonance. otherwise, theory is in good general qualitative agreement with the new data, except for differences in the position and shape of certain features. a fourth feature in the spectrum, resolved for the first time, is observed to be lorentzian in shape, contrary to predictions. the researchers conclude that, while our understanding of this three - electron system has advanced considerably in the past few years, further improvements in theory are still needed. research conducted by r. c. bilodeau and g. turri ( western michigan university and als ) ; j. d. bozek and g. d. ackerman ( als ) ; a. aguilar ( als and university of nevada, reno ) ; and n. berrah ( western michigan university ). research funding : u. s. department of energy, office of basic energy sciences ( bes ). operation of the als is supported


( files in red – history ) 8. positive ions 8h. arrhenius, 1884 9. magnetic trapping 9h. poincare, 1896 10. trapped motion 10h. einstein, 1910 10a. particle drift 11. explorers 1 / 3 11a. geiger counter 12. rad. belts 12h. argus 1958 12a. inner belt 12b. outer belt 13. fast particles 14. synch. orbit going in circlesthe fact charged particles circle around field lines was well known to j. j. thomson when he experimented with electron and ion beams in a magnetic field. in 1930 ernest lawrence of berkeley applied such circular motion to a machine in which he accelerated ions to high energies and which he named " cyclotron. " higher energy particles describe bigger circles, so over the years, as accelerators achieved higher and still higher energies, cyclotrons and their descendants greatly increased in size. the particles inside the tevatron at fermilab in illinois need a diameter of about a mile, and a much bigger machine, the ssc or " superconducting super - collider ", was started in texas but left unfinished when its funds were cut off. giant accelerators of this form, in tunnels deep underground, also exists in the european cern facility near geneva, where they stretch across the french - swiss border. the fermilab magnet is shaped like a huge ring whose cross - section resembles the letter " c ". inside the " c ", where the magnetic field is strong, is the pipe in which protons ( and antiprotons ) are accelerated ( the " c " cradles it the way the rim of a bicycle wheel cradles the inner tube ). that pipe also forms a ring about a mile across, with a vacuum on the inside. the magnet is really an electromagnet, and as the accelerated protons gain speed and energy, its electric current is gradually increased, strengthening the magnetic field in a way that keeps the orbits of the protons within the pipe. early history of adiabatic invariance : the notion of adiabatic invariance is tied with the early years of quantum theory. light emitted from atoms ( or absorbed by them ) has a very well defined pattern of colors - - only a few well - defined colors are involved. ( for more about this, see here. ) by about1910, physicists realized that these patterns indicated changes in the laws of physics as one approached atomic dimensions. atoms