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In mathematics , more specifically non-commutative ring theory , modern algebra , and module theory , the Jacobson density theorem is a theorem concerning simple modules over a ring R . [ 1 ]
The theorem can be applied to show that any primitive ring can be viewed as a "dense" subring of the ring of linear transformations of a vector space. [ 2 ] [ 3 ] This theorem first appeared in the literature in 1945, in the famous paper "Structure Theory of Simple Rings Without Finiteness Assumptions" by Nathan Jacobson . [ 4 ] This can be viewed as a kind of generalization of the Artin-Wedderburn theorem 's conclusion about the structure of simple Artinian rings .
Let R be a ring and let U be a simple right R -module. If u is a non-zero element of U , u • R = U (where u • R is the cyclic submodule of U generated by u ). Therefore, if u, v are non-zero elements of U , there is an element of R that induces an endomorphism of U transforming u to v . The natural question now is whether this can be generalized to arbitrary (finite) tuples of elements. More precisely, find necessary and sufficient conditions on the tuple ( x 1 , ..., x n ) and ( y 1 , ..., y n ) separately, so that there is an element of R with the property that x i • r = y i for all i . If D is the set of all R -module endomorphisms of U , then Schur's lemma asserts that D is a division ring, and the Jacobson density theorem answers the question on tuples in the affirmative, provided that the x i are linearly independent over D .
With the above in mind, the theorem may be stated this way:
In the Jacobson density theorem, the right R -module U is simultaneously viewed as a left D -module where D = End( U R ) , in the natural way: g • u = g ( u ) . It can be verified that this is indeed a left module structure on U . [ 6 ] As noted before, Schur's lemma proves D is a division ring if U is simple, and so U is a vector space over D .
The proof also relies on the following theorem proven in ( Isaacs 1993 ) p. 185:
We use induction on | X | . If X is empty, then the theorem is vacuously true and the base case for induction is verified.
Assume X is non-empty, let x be an element of X and write Y = X \{ x }. If A is any D -linear transformation on U , by the induction hypothesis there exists s ∈ R such that A ( y ) = y • s for all y in Y . Write I = ann R ( Y ) . It is easily seen that x • I is a submodule of U . If x • I = 0 , then the previous theorem implies that x would be in the D -span of Y , contradicting the D -linear independence of X , therefore x • I ≠ 0 . Since U is simple, we have: x • I = U . Since A ( x ) − x • s ∈ U = x • I , there exists i in I such that x • i = A ( x ) − x • s .
Define r = s + i and observe that for all y in Y we have:
Now we do the same calculation for x :
Therefore, A ( z ) = z • r for all z in X , as desired. This completes the inductive step of the proof. It follows now from mathematical induction that the theorem is true for finite sets X of any size.
A ring R is said to act densely on a simple right R -module U if it satisfies the conclusion of the Jacobson density theorem. [ 7 ] There is a topological reason for describing R as "dense". Firstly, R can be identified with a subring of End( D U ) by identifying each element of R with the D linear transformation it induces by right multiplication. If U is given the discrete topology , and if U U is given the product topology , and End( D U ) is viewed as a subspace of U U and is given the subspace topology , then R acts densely on U if and only if R is dense set in End( D U ) with this topology. [ 8 ]
The Jacobson density theorem has various important consequences in the structure theory of rings. [ 9 ] Notably, the Artin–Wedderburn theorem 's conclusion about the structure of simple right Artinian rings is recovered. The Jacobson density theorem also characterizes right or left primitive rings as dense subrings of the ring of D -linear transformations on some D -vector space U , where D is a division ring. [ 3 ]
This result is related to the Von Neumann bicommutant theorem , which states that, for a *-algebra A of operators on a Hilbert space H , the double commutant A′′ can be approximated by A on any given finite set of vectors. In other words, the double commutant is the closure of A in the weak operator topology . See also the Kaplansky density theorem in the von Neumann algebra setting. | https://en.wikipedia.org/wiki/Jacobson_density_theorem |
In algebra, the Jacobson–Bourbaki theorem is a theorem used to extend Galois theory to field extensions that need not be separable. It was introduced by Nathan Jacobson ( 1944 ) for commutative fields and extended to division rings by Jacobson (1947) , and Henri Cartan ( 1947 ) who credited the result to unpublished work by Nicolas Bourbaki . The extension of Galois theory to normal extensions is called the Jacobson–Bourbaki correspondence , which replaces the correspondence between some subfields of a field and some subgroups of a Galois group by a correspondence between some sub division rings of a division ring and some subalgebras of an associative algebra.
The Jacobson–Bourbaki theorem implies both the usual Galois correspondence for subfields of a Galois extension, and Jacobson's Galois correspondence for subfields of a purely inseparable extension of exponent at most 1.
Suppose that L is a division ring .
The Jacobson–Bourbaki theorem states that there is a natural 1:1 correspondence between:
The sub division ring and the corresponding subalgebra are each other's commutants.
Jacobson (1956 , Chapter 7.2) gave an extension to sub division rings that might have infinite index, which correspond to closed subalgebras in the finite topology. | https://en.wikipedia.org/wiki/Jacobson–Bourbaki_theorem |
In mathematics, the Jacobson–Morozov theorem is the assertion that nilpotent elements in a semi-simple Lie algebra can be extended to sl 2 -triples . The theorem is named after Jacobson 1951 , Morozov 1942 .
The statement of Jacobson–Morozov relies on the following preliminary notions: an sl 2 -triple in a semi-simple Lie algebra g {\displaystyle {\mathfrak {g}}} (throughout in this article, over a field of characteristic zero ) is a homomorphism of Lie algebras s l 2 → g {\displaystyle {\mathfrak {sl}}_{2}\to {\mathfrak {g}}} . Equivalently, it is a triple e , f , h {\displaystyle e,f,h} of elements in g {\displaystyle {\mathfrak {g}}} satisfying the relations
An element x ∈ g {\displaystyle x\in {\mathfrak {g}}} is called nilpotent, if the endomorphism [ x , − ] : g → g {\displaystyle [x,-]:{\mathfrak {g}}\to {\mathfrak {g}}} (known as the adjoint representation ) is a nilpotent endomorphism . It is an elementary fact that for any sl 2 -triple ( e , f , h ) {\displaystyle (e,f,h)} , e must be nilpotent. The Jacobson–Morozov theorem states that, conversely, any nilpotent non-zero element e ∈ g {\displaystyle e\in {\mathfrak {g}}} can be extended to an sl 2 -triple. [ 1 ] [ 2 ] For g = s l n {\displaystyle {\mathfrak {g}}={\mathfrak {sl}}_{n}} , the sl 2 -triples obtained in this way are made explicit in Chriss & Ginzburg (1997 , p. 184).
The theorem can also be stated for linear algebraic groups (again over a field k of characteristic zero): any morphism (of algebraic groups) from the additive group G a {\displaystyle G_{a}} to a reductive group H factors through the embedding
Furthermore, any two such factorizations
are conjugate by a k -point of H .
A far-reaching generalization of the theorem as formulated above can be stated as follows: the inclusion of pro-reductive groups into all linear algebraic groups, where morphisms G → H {\displaystyle G\to H} in both categories are taken up to conjugation by elements in H ( k ) {\displaystyle H(k)} , admits a left adjoint , the so-called pro-reductive envelope. This left adjoint sends the additive group G a {\displaystyle G_{a}} to S L 2 {\displaystyle SL_{2}} (which happens to be semi-simple, as opposed to pro-reductive), thereby recovering the above form of Jacobson–Morozov.
This generalized Jacobson–Morozov theorem was proven by André & Kahn (2002 , Theorem 19.3.1) by appealing to methods related to Tannakian categories and by O'Sullivan (2010) by more geometric methods. | https://en.wikipedia.org/wiki/Jacobson–Morozov_theorem |
In mathematics , Jacobsthal sums are finite sums of Legendre symbols related to Gauss sums . They were introduced by Jacobsthal ( 1907 ).
The Jacobsthal sum is given by
where p is prime and () is the Legendre symbol . | https://en.wikipedia.org/wiki/Jacobsthal_sum |
Jacobus Henricus van 't Hoff Jr. ( Dutch: [vɑn (ə)t ˈɦɔf] ; 30 August 1852 – 1 March 1911) was a Dutch physical chemist . A highly influential theoretical chemist of his time, Van 't Hoff was the first winner of the Nobel Prize in Chemistry . [ 3 ] [ 4 ] [ 5 ] His pioneering work helped found the modern theory of chemical affinity , chemical equilibrium , chemical kinetics , and chemical thermodynamics . In his 1874 pamphlet, Van 't Hoff formulated the theory of the tetrahedral carbon atom and laid the foundations of stereochemistry . In 1875, he predicted the correct structures of allenes and cumulenes as well as their axial chirality . [ 6 ] He is also widely considered one of the founders of physical chemistry as the discipline is known today. [ 7 ] [ 8 ] [ 9 ]
The third of seven children, Van 't Hoff was born in Rotterdam , Netherlands, 30 August 1852. His father was Jacobus Henricus van 't Hoff Sr., a physician, and his mother was Alida Kolff van 't Hoff. [ 10 ] From a young age, he was interested in science and nature, and frequently took part in botanical excursions. In his early school years, he showed a strong interest in poetry and philosophy . He considered Lord Byron to be his idol.
Against the wishes of his father, Van 't Hoff chose to study chemistry . First, he enrolled at Delft University of Technology in September 1869, and studied until 1871, when he passed his final exam on 8 July and obtained a degree of chemical technologist . [ 11 ] [ 12 ] [ 13 ] He passed all his courses in two years, although the time assigned to study was three years. [ 11 ] [ 12 ] [ 13 ] Then he enrolled at University of Leiden to study chemistry. He then studied in Bonn , Germany, with August Kekulé and in Paris with Adolphe Wurtz . He received his doctorate under Eduard Mulder at the University of Utrecht in 1874. [ 14 ]
In 1878, Van 't Hoff married Johanna Francina Mees. They had two daughters, Johanna Francina (1880–1964) and Aleida Jacoba (1882–1971), and two sons, Jacobus Henricus van 't Hoff III (1883–1943) and Govert Jacob (1889–1918). Van 't Hoff died at the age of 58, on 1 March 1911, at Steglitz , near Berlin, of tuberculosis .
Van 't Hoff earned his earliest reputation in the field of organic chemistry . In 1874, he accounted for the phenomenon of optical activity by assuming that the chemical bonds between carbon atoms and their neighbors were directed towards the corners of a regular tetrahedron . [ 15 ] [ 16 ] This three-dimensional structure accounted for the isomers found in nature. He shares credit for this with the French chemist Joseph Le Bel , who independently came up with the same idea.
Three months before his doctoral degree was awarded, Van 't Hoff published this theory, which today is regarded as the foundation of stereochemistry , first in a Dutch pamphlet in the fall of 1874, and then in the following May in a small French book entitled La chimie dans l'espace . A German translation appeared in 1877, at a time when the only job Van 't Hoff could find was at the Veterinary School in Utrecht. In these early years his theory was largely ignored by the scientific community, and was sharply criticized by one prominent chemist, Hermann Kolbe . Kolbe wrote:
"A Dr. J. H. van 't Hoff of the Veterinary School at Utrecht has no liking, apparently, for exact chemical investigation. He has considered it more convenient to mount Pegasus (apparently borrowed from the Veterinary School) and to proclaim in his ‘La chimie dans l’espace’ how, in his bold flight to the top of the chemical Parnassus, the atoms appeared to him to be arranged in cosmic space."
However, by about 1880, support for Van 't Hoff's theory by such important chemists as Johannes Wislicenus and Viktor Meyer brought recognition.
In 1884, Van 't Hoff published his research on chemical kinetics, titled Études de Dynamique chimique ( "Studies in Chemical Dynamics" ), in which he described a new method for determining the order of a reaction using graphics and applied the laws of thermodynamics to chemical equilibria. He also introduced the modern concept of chemical affinity . In 1886, he showed a similarity between the behaviour of dilute solutions and gases. In 1887, he and German chemist Wilhelm Ostwald founded an influential scientific magazine named Zeitschrift für physikalische Chemie (" Journal of Physical Chemistry "). He worked on Svante Arrhenius 's theory of the dissociation of electrolytes and in 1889 provided physical justification for the Arrhenius equation . In 1896, he became a professor at the Prussian Academy of Sciences in Berlin. His studies of the salt deposits at Stassfurt were an important contribution to Prussia's chemical industry.
Van 't Hoff became a lecturer in chemistry and physics at the Veterinary College in Utrecht . He then worked as a professor of chemistry, mineralogy , and geology at the University of Amsterdam for almost 18 years before eventually becoming the chairman of the chemistry department. In 1896, van 't Hoff moved to Germany, where he finished his career at the University of Berlin in 1911. In 1901, he received the first Nobel Prize in Chemistry for his work with solutions. His work showed that very dilute solutions follow mathematical laws that closely resemble the laws describing the behavior of gases .
In 1885, Van 't Hoff was appointed as a Member of the Royal Netherlands Academy of Arts and Sciences . [ 17 ] In 1904, he was elected as a member to the American Philosophical Society . [ 18 ] Other distinctions include honorary doctorates from Harvard and Yale (1901), Victoria University , the University of Manchester (1903), and University of Heidelberg (1908). He was awarded the Davy Medal of the Royal Society in 1893 (along with Le Bel ), and elected a Foreign Member of the Royal Society (ForMemRS) in 1897 . He was awarded the Helmholtz Medal of the Prussian Academy of Sciences (1911), and appointed Knight of the French Legion of Honour (1894) and Senator in the Kaiser-Wilhelm-Gesellschaft (1911). Van 't Hoff became an Honorary Member of the British Chemical Society in London, the Royal Netherlands Academy of Arts and Sciences (1892), American Chemical Society (1898), the Académie des Sciences in Paris (1905), and the Netherlands Chemical Society (1908). Of his numerous distinctions, Van 't Hoff regarded winning the first Nobel Prize in Chemistry as the culmination of his career. [ 19 ] The following are named after him: [ citation needed ]
On 14 May 2021, asteroid 34978 van 't Hoff , discovered by astronomers with the Palomar–Leiden survey in 1977, was named in his memory. [ 20 ] | https://en.wikipedia.org/wiki/Jacobus_Henricus_van_'t_Hoff |
The Jacquard machine ( French: [ʒakaʁ] ) is a device fitted to a loom that simplifies the process of manufacturing textiles with such complex patterns as brocade , damask and matelassé . [ 3 ] The resulting ensemble of the loom and Jacquard machine is then called a Jacquard loom . The machine was patented by Joseph Marie Jacquard in 1804, [ 4 ] [ 5 ] [ 6 ] [ 7 ] based on earlier inventions by the Frenchmen Basile Bouchon (1725), Jean Baptiste Falcon (1728), and Jacques Vaucanson (1740). [ 8 ] The machine was controlled by a "chain of cards"; a number of punched cards laced together into a continuous sequence. [ 9 ] Multiple rows of holes were punched on each card, with one complete card corresponding to one row of the design.
Both the Jacquard process and the necessary loom attachment are named after their inventor. This mechanism is probably one of the most important weaving innovations, as Jacquard shedding made possible the automatic production of unlimited varieties of complex pattern weaving. The term "Jacquard" is not specific or limited to any particular loom, but rather refers to the added control mechanism that automates the patterning. The process can also be used for patterned knitwear and machine-knitted textiles such as jerseys . [ 10 ]
This use of replaceable punched cards to control a sequence of operations is considered an important step in the history of computing hardware , having inspired Charles Babbage 's Analytical Engine .
Traditionally, figured designs were made on a drawloom . The heddles with warp ends to be pulled up were manually selected by a second operator, the draw boy, not the weaver. The work was slow and labour-intensive, and the complexity of the pattern was limited by practical factors.
The first prototype of a Jacquard-type loom was made in the second half of the 15th century by an Italian weaver from Calabria , Jean le Calabrais, who was invited to Lyon by Louis XI . [ 11 ] [ 12 ] He introduced a new kind of machine which was able to work the yarns faster and more precisely. Over the years, improvements to the loom were ongoing. [ 13 ]
An improvement of the draw loom took place in 1725, when Basile Bouchon introduced the principle of applying a perforated band of paper. A continuous roll of paper was punched by hand, in sections, each of which represented one lash or tread, and the length of the roll was determined by the number of shots in each repeat of pattern. The Jacquard machine then evolved from this approach.
Joseph Marie Jacquard saw that a mechanism could be developed for the production of sophisticated patterns. He possibly combined mechanical elements of other inventors, but certainly innovated. His machine was generally similar to Vaucanson 's arrangement, but he made use of Jean-Baptiste Falcon's individual pasteboard cards and his square prism (or card "cylinder"): he is credited with having fully perforated each of its four sides, replacing Vaucanson's perforated "barrel". Jacquard's machine contained eight rows of needles and uprights, where Vaucanson had a double row. This modification enabled him to increase the figuring capacity of the machine. In his first machine, he supported the harness by knotted cords, which he elevated by a single trap board.
One of the chief advantages claimed for the Jacquard machine was that unlike previous damask-weaving machines, in which the figuring shed was usually drawn once for every four shots, with the new apparatus, it could be drawn on every shot, thus producing a fabric with greater definition of outline. [ 14 ]
Jacquard's invention had a deep influence on Charles Babbage . In that respect, he is viewed by some authors as a precursor of modern computing technology. [ 15 ]
As shown in the diagram, the cards are fastened into a continuous chain (1) which passes over a square box. At each quarter rotation, a new card is presented to the Jacquard head which represents one row (one "pick" of the shuttle carrying the weft ). The box swings from the right to the position shown and presses against the control rods (2). For each hole in the card, a rod passes through and is unmoved; where there is no hole, a rod is pushed to the left. Each rod acts upon a hook (3). When the rod is pushed in, the hook moves out of position to the left; a rod that is not pushed in leaves its hook in place. A beam (4) then rises under the hooks, and the hooks in the rest position are raised. The hooks that have been displaced are not moved by the beam. Each hook can have multiple cords (5). Each cord passes through a guide (6) and is attached to a corresponding heddle (7) and return weight (8). The heddles raise the warp to create the shed through which the shuttle carrying the weft will pass. [ 16 ] A loom with a 400-hook head might have four threads connected to each hook, resulting in a fabric that is 1600 warp ends wide with four repeats of the weave going across.
The term "Jacquard loom" is somewhat inaccurate. It is the "Jacquard head" that adapts to a great many dobby looms that allow the weaving machine to then create the intricate patterns often seen in Jacquard weaving.
Jacquard-driven looms, although relatively common in the textile industry, are not as ubiquitous as dobby looms which are usually faster and much cheaper to operate. However, dobby looms are not capable of producing many different weaves from one warp . Modern jacquard machines are controlled by computers in place of the original punched cards and can have thousands of hooks.
The threading of a Jacquard machine is so labor-intensive that many looms are threaded only once. Subsequent warps are then tied into the existing warp with the help of a knotting robot which ties on each new thread individually. Even for a small loom with only a few thousand warp ends , the process of re-threading can take days.
Originally, Jacquard machines were mechanical , and the fabric design was stored on a series of punched cards which were joined to form a continuous chain. The Jacquards were often small and controlled relatively few warp ends. This required a number of repeats across the loom width. Larger capacity machines, or the use of multiple machines, allowed greater control with fewer repeats; hence, larger designs could be woven across the loom width.
A factory must choose looms and shedding mechanisms to suit its commercial requirements. As a rule, greater warp control means greater expense. So it is not economical to purchase Jacquard machines if one can make do with a dobby mechanism . Beyond the capital expense, Jacquard machines cost more to maintain as they are complex, require highly-skilled operators, and use expensive systems to prepare designs for the loom. Thus, they are more likely to produce faults than dobby or cam shedding. Also, the looms will not run as quickly and down-time will increase because it takes time to change the continuous chain of cards when a design changes. It is best to weave larger batches with mechanical Jacquards.
In 1855, a Frenchman [ 17 ] adapted the Jacquard mechanism to a system by which it could be worked by electro-magnets. There was significant interest, but trials were not successful, and the development was soon forgotten.
Bonas Textile Machinery NV launched the first successful electronic Jacquard at ITMA Milan in 1983. [ 18 ] [ a ] Although the machines were initially small, modern technology has allowed Jacquard machine capacity to increase significantly, and single end warp control can extend to more than 10,000 warp ends. [ 20 ] This eliminates the need for repeats and symmetrical designs and invites almost infinite versatility. The computer-controlled machines significantly reduce the down time associated with changing punchcards, thereby allowing smaller batch sizes. However, electronic Jacquards are costly and may not be necessary in a factory weaving large batch sizes and smaller designs. Larger machines accommodating single-end warp control are very expensive and can only be justified when great versatility or very specialized designs are required. For example, they are an ideal tool to increase the ability and versatility of niche linen Jacquard weavers who remain active in Europe and the West, while most large batch commodity weaving has moved to low-cost production. [ citation needed ]
Linen products associated with Jacquard weaving are linen damask napery, Jacquard apparel fabrics and damask bed linen. Jacquard weaving uses all sorts of fibers and blends of fibers, and it is used in the production of fabrics for many end uses. Jacquard weaving can also be used to create fabrics that have a Matelassé or a brocade pattern. [ 21 ]
A pinnacle of production using a Jacquard machine is a prayer book, woven in silk, entitled Livre de Prières. Tissé d'après les enluminures des manuscrits du XIVe au XVIe siècle . [ 22 ] All 58 pages of the prayer book were woven silk, made with a Jacquard machine using black and gray thread, at 160 threads per cm (400 threads per inch). The pages have elaborate borders with text and pictures of saints. According to book historian Michael Laird, an estimated 106,000 to 500,000 punchcards were necessary to encode the pages. [ 23 ]
The book was issued in 1886 and 1887 in Lyon, France, and was publicly displayed at the 1889 Exposition Universelle (World's Fair). It was designed by R. P. J. Hervier, woven by J. A. Henry, and published by A. Roux. [ 23 ] It took two years and almost 50 trials to get correct. An estimated 50 or 60 copies were produced.
The manufacture of the volume employed the Jacquard method of using punch cards which J.A. Henry first used in Les laboureurs. Poème tiré de Jocelyn. Reproduit en caractères tissés avec license des propriétaires éditeurs (by Alphonse de Lamartine ) in 1878. That earlier title is the true "first book 'printed' by computer". [ 24 ]
The Jacquard head used replaceable punched cards to control a sequence of operations. It is considered an important step in the history of computing hardware . [ 25 ] The ability to change the pattern of the loom's weave by simply changing cards was an important conceptual precursor to the development of computer programming and data entry. Charles Babbage knew of Jacquard machines and planned to use cards to store programs in his Analytical Engine . In the late 19th century, Herman Hollerith took the idea of using punched cards to store information a step further when he created a punched card tabulating machine which he used to input data for the 1890 U.S. Census . A large data processing industry using punched-card technology was developed in the first half of the twentieth century—dominated initially by the International Business Machine corporation (IBM) with its line of unit record equipment . The cards were used for data, however, with programming done by plugboards .
Some early computers, such as the 1944 IBM Automatic Sequence Controlled Calculator (Harvard Mark I) received program instructions from a paper tape punched with holes, similar to Jacquard's string of cards. Later computers executed programs from higher-speed memory, though cards were commonly used to load the programs into memory. Punched cards remained in use in computing up until the mid-1980s. | https://en.wikipedia.org/wiki/Jacquard_machine |
Jacques-François Le Poivre (11 February 1652 [ 1 ] – 6 December 1710) was a mathematician and geometer who was a pioneer of projective geometry . He is largely known from a single book in French on conic sections, Traité des sections du cylindrie et du cône considérées dans le solide et dans le plan, avec des démonstrations simples & nouvelles (1704).
Le Poivre was born in Mons to son of Jacques and Catherine Demeurs. The Le Poivre family had many engineers including Pierre Le Poivre (1546-1626), an architect and military engineer. Jacques-François too studied mathematics and geometry and worked as a clerk and surveyor for the city of Mons. In 1700 he moved to Paris and in 1704 he published a treatise in two parts on cylindrical and conic sections . This work largely escaped serious study and some reviewers considered it to be plagiarism of Philippe de la Hire . In any case, de la Hire's work was more well-known. In part 2, his method of central projection was essentially the same as used by de La Hire in his 1673 work Nouvelle méthode en géométrie, pour les sections des superficies coniques et cylindriques but it has been suggested that Le Poivre independently discovered this since [ 2 ] the book included several original theorems. A second edition of the Traité was published in 1708. An earlier work on an introduction to arithmetic that Le Poivre published in 1687 has never been located. He was a friend of Guillaume de l'Hôpital and a simple proof of the intersecting chords theorem by Le Poivre impressed l'Hôpital and may have made its way into l'Hôpital's Traité analytique des sections coniques . [ 3 ] [ 4 ] [ 5 ] A biography claimed that Le Poivre was a poet. [ 6 ] | https://en.wikipedia.org/wiki/Jacques-François_Le_Poivre |
Jacques Bouveresse ( French: [ʒak buvʁɛs] ; 20 August 1940 – 9 May 2021) was a French philosopher who wrote on subjects including Ludwig Wittgenstein , Robert Musil , Karl Kraus , philosophy of science , epistemology , philosophy of mathematics and analytical philosophy . Bouveresse was called "an avis rara among the better known French philosophers in his championing of critical standards of thought." [ 4 ]
He was Professor Emeritus at the Collège de France where until 2010 he held the chair of philosophy of language and epistemology. His disciple Claudine Tiercelin was appointed to a chair of metaphysics and philosophy of knowledge upon his retirement.
Born on 20 August 1940 in Épenoy in the Doubs département of France into a farming family, Jacques Bouveresse completed his secondary education at the seminary of Besançon . He spent two years of preparation for the baccalauréat in philosophy and scholastic theology at Faverney in Haute-Saône . He followed his preparatory literary classes at the Lycée Lakanal in Sceaux , and in 1961 entered the École Normale Supérieure in Paris.
He presented his doctoral thesis in philosophy on Wittgenstein , entitled "Le mythe de l'intériorité. Expérience, signification et langage privé chez Wittgenstein".
Beginning with his earliest works, he consistently constructed his own philosophical and intellectual path, without following the normal routes and modes of academia. In 1976, Wittgenstein was practically unknown in France, as were Musil and the logic and analytical philosophy which Bouveresse had begun to study in the 1960s. [ citation needed ] These two last domains notably propelled him towards the lectures of Jules Vuillemin and Gilles Gaston Granger , who at the time were practically alone in occupying themselves with these problems, and with whom he maintained a lasting friendship.
Academic career:
Bouveresse's philosophy is a continuation of the intellectual and philosophical tradition of central Europe ( Brentano , Boltzmann , Helmholtz , Frege , the Vienna Circle , Kurt Gödel ). His philosophical programme is in nearly all respects similar to the one conducted by many present day Analytic philosophers . [ 1 ]
Jacques Bouveresse is interested in the thought of the early 20th-century Austrian novelist Robert Musil (who wrote a thesis on philosophy), famous for his novel The Man Without Qualities , as well as the aversion/fascination with which Paul Valéry regarded philosophy.
Apart from his work on Ludwig Wittgenstein, Jacques Bouveresse is interested in the incompleteness theorems of Kurt Gödel and their philosophical consequences. It is on this account that he has attacked, in a popular work Prodiges et vertiges de l'analogie , the use made of these theorems by Régis Debray . Bouveresse denounces the literary distortion of a scientific concept for the purpose of a thesis. This distortion, according to him, has no other purpose than to overwhelm a readership which lacks the training necessary to comprehend such complex theorems. Bouveresse's reproach to Debray is not that he uses a scientific concept for the purpose of an analogy, but that he uses such a difficult to understand theorem in the attempt to provide an absolute justification in the form of the classic sophism of the argument from authority.
According to Bouveresse, the incompleteness of a formal system which applies to certain mathematical systems in no way implies the incompleteness of sociology , which is not a formal system.
Unless stated otherwise, published by Éditions de Minuit. Most books published by the Collège de France editions are freely accessible on the Collège's website . | https://en.wikipedia.org/wiki/Jacques_Bouveresse |
Jacques Edwin Brandenberger (19 October 1872 – 13 July 1954) was a Swiss chemist and textile engineer who in 1908 invented cellophane . He was awarded the Franklin Institute 's Elliott Cresson Medal in 1937.
Brandenberger was born in Zurich in 1872. He graduated from the University of Bern in 1895. In 1908 Brandenberger invented cellophane. Made from wood cellulose , cellophane was intended as a coating to make cloth more resistant to staining. After several years of further research and refinements, he began production of cellophane in 1920 marketing it for industrial purposes. He sold the US rights to DuPont in 1923. [ 1 ]
This biographical article about a chemist is a stub . You can help Wikipedia by expanding it .
This article about a Swiss scientist is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jacques_E._Brandenberger |
Jacques Pelletier du Mans , also spelled Peletier ( Latin : Iacobus Peletarius Cenomani , 25 July 1517 – 17 July 1582) was a humanist , poet and mathematician of the French Renaissance . [ 1 ]
Born in Le Mans into a bourgeois family, he studied at the Collège de Navarre in Paris , where his brother Jean was a professor of mathematics and philosophy. He subsequently studied law and medicine, frequented the literary circle around Marguerite de Navarre and from 1541 to 1543 he was secretary to René du Bellay. In 1541 he published the first French translation of Horace 's Ars Poetica and during this period he also published numerous scientific and mathematical treatises.
In 1547 he produced a funeral oration for Henry VIII of England and published his first poems ( Œuvres poétiques ), which included translations from the first two cantos of Homer 's Odyssey and the first book of Virgil 's Georgics , twelve Petrarchian sonnets , three Horacian odes and a Martial-like epigram ; this poetry collection also included the first published poems of Joachim Du Bellay and Pierre de Ronsard (Ronsard would include Jacques Pelletier into his list of revolutionary contemporary poets ( La Pléiade ). He then began to frequent a humanist circle around Théodore de Bèze , Jean Martin, Denis Sauvage.
In the Renaissance, the French language had acquired many inconsistencies in spelling through attempts to model French words on their Latin roots (see Middle French ). Pelletier tried to reform French spelling in his 1550 treatise Dialoguɇ Dɇ l’Ortografɇ e Prononciation Françoęſɇ ("Dialogue on French spelling and pronunciation"), [ 2 ] advocating a phonetic-based spelling using new typographic signs which he would continue to use in all his published works. In this system, he consistently spells his name with one "l": Iacquɇs Pɇlɇtier du Mans .
Pelletier was principal of the Collège de Bayeux [ 3 ] and subsequently spent many years in Bordeaux , Poitiers , Piedmont (where he may have been the tutor of the son of Maréchal de Brissac ), and Lyon (where he frequented the poets and humanists Maurice Scève , Louise Labé , Olivier de Magny and Pontus de Tyard ). In 1555 he published a manual of poetic composition, Art poétique français , a Latin oration calling for peace from King Henry II and Emperor Charles V , and a new collection of poetry, L'Amour des amours (consisting of a sonnet cycle and a series of encyclopedic poems describing meteors, planets and the heavens), which would influence that poets Guillaume du Bartas and Jean-Antoine de Baïf .
His last years were spent in travels to the Savoy , Germany, Switzerland, possibly Italy and various regions in France and in publishing numerous works in Latin on algebra , geometry and mathematics and medicine (including a refutation of Galen and a work on the plague ). In 1572, he was briefly director of the College of Aquitaine in Bordeaux, but, bored by the position, he resigned. During this period, he was friends with Michel de Montaigne and Pierre de Brach . In 1579, he returned to Paris and was named director of the College of Le Mans. A final collection of poetry Louanges was published in 1581.
Pelletier died in Paris in July or August 1582.
While maintaining the original system of the French mathematician Nicolas Chuquet (1484) for the names of large numbers, Jacques Pelletier promoted milliard for 10 12 which had been used earlier by Budaeus . In the late 17th century, milliard was subsequently reduced to 10 9 . This convention is used widely in long scale countries . | https://en.wikipedia.org/wiki/Jacques_Pelletier_du_Mans |
Jadav " Molai " Payeng (born 31 October 1959) is an environmental activist [ 1 ] and forestry worker from Majuli , [ 2 ] popularly known as the Forest Man of India . [ 3 ] [ 4 ] Over the course of several decades, he has planted and tended trees on a sandbar of the river Brahmaputra turning it into a forest reserve. The forest, called Molai forest after him, [ 5 ] is located near Kokilamukh of Jorhat , Assam, India and encompasses an area of about 1,360 acres / 550 hectares . [ 6 ] [ 7 ] In 2015, he was honoured with Padma Shri , the fourth highest civilian award in India. [ 8 ] He was born in the indigenous Mising tribe [ 9 ] of Assam.
In 1979, Payeng, then 16, encountered a large number of snakes that had died due to excessive heat after floods washed them onto the tree-less sandbar. That is when he planted around 20 bamboo seedlings on the sandbar. [ 7 ] [ 10 ] He not only looked after the plants, but continued to plant more trees on his own, in an effort to transform the area into a forest.
The forest, which came to be known as Molai forest, now houses Bengal tigers , Indian rhinoceros , and over 100 deer and rabbits. Molai forest is also home to monkeys and several varieties of birds, including a large number of vultures. [ 6 ] There are several thousand trees, including valcol, arjun ( Terminalia arjuna ), ejar ( Lagerstroemia speciosa ), goldmohur ( Delonix regia ), koroi ( Albizia procera ), moj ( Archidendron bigeminum ) and himolu ( Bombax ceiba ). Bamboo covers an area of over 300 hectares. [ 11 ]
A herd of around 100 elephants regularly visits the forest every year and generally stays for around six months. They have given birth to 10 calves in the forest in recent years. [ 11 ]
His efforts became known to the authorities in 2008, when forest department officials went to the area in search of 115 elephants that had retreated into the forest after damaging property in the village of Aruna Chapori, which is about 1.5 km from the forest. The officials were surprised to see such a large and dense forest and since then the department has regularly visited the site. [ 11 ]
In 2013, poachers tried to kill the rhinos staying in the forest but failed in their attempt due to Molai who alerted department officials. Officials promptly seized various articles used by the poachers to trap the animals. [ 11 ]
Molai is ready to manage the forest in a better way and to go to other places of the state to start a similar venture. Now his aim is to spread his forest to another sand bar inside of Brahmaputra. [ 12 ] [ 13 ]
He belongs to the indigenous Mising Tribe which located in Assam India. He, along with wife and 3 children (1 daughter and 2 sons), used to live at the house which he had built inside his Forest. In 2012, Jadav built a house at No. 1 Mishing Gaon near Kokilmukh Ghat and shifted to this house with his family. Since then, they have been living in this house. Jadav, however, travels everyday to his Forest to tend and look after the plants and trees. He has cattle and buffalo on his farm and sells the milk for his livelihood, which is his only source of income. [ 6 ] In an interview from 2012, he revealed that he has lost around 100 of his cows and buffaloes to the tigers in the forest, but blames the people who carry out large scale encroachment and destruction of forests as the root cause of the plight of wild animals. [ 12 ]
Jadav Payeng was honoured at a public function arranged by the School of Environmental Sciences, Jawaharlal Nehru University [ 14 ] on 22 April 2012 for his achievement. He shared his experience of creating a forest in an interactive session, where Magsaysay Award winner Rajendra Singh and JNU vice-chancellor Sudhir Kumar Sopory were present. Sopory named Jadav Payeng as the "Forest Man of India" . [ 7 ] [ 15 ] In the month of October 2013, he was honoured at the Indian Institute of Forest Management during their annual event Coalescence. In 2015, he was honoured with Padma Shri , the fourth highest civilian award in India. He received honorary doctorate degree from Assam Agricultural University and Kaziranga University for his contributions.
Payeng has been the subject of a number of documentaries in the recent years. His character was the basis for a fictional film made by a Tamil director Prabhu solaman casting Rana Daggubati released in Tamil, Telugu, Hindi as Kaadan , Aranya and Haathi Mere Saathi (2018 film) . A locally made documentary film, produced by Jitu Kalita in 2012, The Molai Forest , [ 16 ] was screened at the Jawaharlal Nehru University . Jitu Kalita, who lives near Payeng's house, has also been featured and given recognition for good reporting by projecting the life of Payeng through his documentary.
The 2013 film documentary Foresting life , [ 17 ] [ 18 ] directed by the Indian documentary filmmaker Aarti Shrivastava , celebrates the life and work of Jadav Payeng in the Molai forest. These are also the focus of William Douglas McMaster's 2013 film documentary Forest Man . [ 19 ] With US$8,327 pledged on its Kickstarter campaign, the film was brought to completion and taken to a number of film festivals. [ 20 ] It was awarded the Best Documentary prize at the Emerging Filmmaker Showcase in the American Pavilion at the 2014 Cannes Film Festival . [ 21 ] [ 22 ]
Payeng is the subject of the 2016 children's book Jadav and the Tree-Place , [ 23 ] written and illustrated by Vinayak Varma. [ 24 ] The book was published by the open-source children's publishing platform StoryWeaver, [ 25 ] [ 26 ] and its production was funded by a grant from the Oracle Giving Initiative. [ 27 ] [ 28 ] Jadav and the Tree-Place has been translated into 39 languages, [ 29 ] published in print by Pratham Books in 8 Indian languages, [ 30 ] and has won the Digital Book of the Year prize at the Publishing Next Industry Awards, 2016, [ 31 ] and the Best of Indian Children's Writing: Contemporary Awards, 2019.
Payeng is also the subject of the 2019 children's book The Boy Who Grew A Forest: The True Story of Jadav Payeng , [ 32 ] [ 33 ] written by Sophia Gholz and illustrated by Kayla Harren. [ 34 ] Published by Sleeping Bear Press, the book won the Crystal Kite Award , [ 35 ] the Sigurd F. Olson Nature Writing Award (SONWA) from Northland College , [ 36 ] and the Florida State Book Award. [ 37 ] It has been translated into German and French, [ 32 ] and adapted for stage. [ 38 ] [ 39 ] | https://en.wikipedia.org/wiki/Jadav_Payeng |
Jadwiga Barbara Ostrowska-Czubenko (born 18 January 1949 in Kołobrzeg ) is a Polish chemist at the Nicolaus Copernicus University in Toruń .
Ostrowska-Czubenko attended the Nicolaus Copernicus University in Toruń , majoring in chemistry. She graduated in 1972, defended her doctoral thesis eight years later, and completed her habilitation in 2002. She is associate professor in the Department of Chemistry at the Nicolaus Copernicus University, where she specializes in physical Chemistry and physicochemistry of polymers.
This article about a Polish scientist is a stub . You can help Wikipedia by expanding it .
This biographical article about a chemist is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jadwiga_Ostrowska-Czubenko |
The Jaffe profile (or Jaffe model) is a mathematical function that is used to describe the distribution of mass or light in elliptical galaxies and the bulges of spiral galaxies . It was proposed by the astronomer Walter Jaffe in 1983. [ 1 ] Its usefulness derives from the fact that it accurately reproduces a de Vaucouleurs profile when projected onto the sky.
The density in the Jaffe model is given by
In this equation, ρ 0 {\displaystyle \rho _{0}} and r 0 {\displaystyle r_{0}} are parameters that can be varied to fit the observed density.
Jaffe described how he arrived at his model: [ 1 ]
[The formula] was derived heuristically from the observation that the brightness profiles of spherical galaxies seem to run as r − 3 {\displaystyle r^{-3}} and r − 1 {\displaystyle r^{-1}} in at least some parts of their envelopes and cores, respectively. This would imply that the spatial density runs as r − 4 {\displaystyle r^{-4}} and r − 2 {\displaystyle r^{-2}} .
Variations on Jaffe's law include the Hernquist profile, the Dehnen profile and the NFW profile , which have a similar functional form as Jaffe's law but which use different values for the two exponents.
This astrophysics -related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jaffe_profile |
The Jaffe reaction is a colorimetric method used in clinical chemistry to determine creatinine levels in blood and urine. In 1886, Max Jaffe (1841–1911) wrote about its basic principles in the paper Über den Niederschlag, welchen Pikrinsäure in normalem Harn erzeugt und über eine neue Reaction des Kreatinins in which he described the properties of creatinine and picric acid in an alkaline solution . The color change that occurred was directly proportional to the concentration of creatinine, however he also noted that several other organic compounds induced similar reactions. In the early 20th century, Otto Folin adapted Jaffe's research into a clinical procedure. The Jaffe reaction, despite its nonspecificity for creatinine, is still widely employed as the method of choice for creatinine testing [ 1 ] due to its speed, adaptability in automated analysis, and cost-effectiveness, and is the oldest methodology continued to be used in the medical laboratory . [ 2 ] It is this nonspecificity that has motivated the development of new reference methods for creatinine analysis into the 21st century.
Max Jaffe was a distinguished 19th-century German biochemist , pathologist , pharmacologist , and professor. [ 4 ] [ 5 ] He was born on July 25, 1841, in what was formerly Grünberg, Silesia and is now Zielona Góra , Poland . [ 5 ] While attending medical school at the University of Berlin , he studied under Ludwig Traube and Wilhelm Kühne . [ 5 ] Afterward, he worked as an assistant in a medical clinic in Königsberg . [ 5 ] There, he co-authored a paper on putrid sputum with Ernst Viktor von Leyden that led to the discovery of certain characteristic putrid processes in the lungs . [ 5 ] After earning his degree in internal medicine , he served in the Franco-Prussian War and was decorated with the Iron Cross Second Class. [ 5 ] The title of Extraordinary Professor of Medicinal Chemistry was awarded to him in 1872 and the following year he became the first Ordinary Professor of Pharmacology at the University of Königsberg . [ 5 ] He was promoted to director of the Laboratory for Medical Chemistry and Experimental Pharmacology in 1878 and became a member of the Deutsche Akademie der Naturforscher Leopoldina in 1882. [ 5 ] Aside from studying creatinine, he is also known for discovering urobilin and urobilinogen in urine and found that these compounds originated in bile . [ 5 ] He died on October 26, 1911, in Berlin and is buried in the Weißensee Cemetery . [ 5 ]
Creatinine was first synthesized in vitro by Ivan Horbaczewski in 1885. [ 5 ] One year later, Jaffe's research was published in the paper Über den Niederschlag, welchen Pikrinsäre in normalem Harn erzeugt und über eine neue Reaction des Kreatinins . [ 6 ] Jaffe had noticed that, when mixed in a sodium hydroxide (NaOH) solution, picric acid and creatinine formed a reddish-orange color and needle-like crystal precipitate . [ 5 ] [ 7 ] [ 8 ] By using zinc chloride in a process known as the Neubauer reaction , and then performing the Weyl's test , a colorimetric reaction using sodium nitroprusside (SNP), he determined that the precipitated compound was a double salt of the solution. [ 8 ] Although he found the amount of precipitate directly proportional to the creatinine concentration, he also noted that the reaction was highly nonspecific and could be observed with many other organic compounds. [ 5 ] [ 7 ]
based on the Jaffe reaction. [ 2 ]
Although Jaffe's name is synonymous with clinical creatinine testing, his paper only described the principle behind what would later become the enduring method. [ 5 ] It was Otto Folin (1867–1934), a Harvard biochemist, who adapted Jaffe's research—abandoning the standard Neubauer reaction of the time—and published several papers using the Jaffe reaction to analyze creatinine levels in both blood and urine. [ 9 ] [ 10 ] [ 11 ] Folin began using the picric acid procedure in 1901 and included it in his 1916 Lab Manual of Biological Chemistry . [ 10 ] [ 12 ] During his career, Folin modified and improved several quantitative colorimetric procedures, the first of which was for creatinine. [ 10 ] He took advantage of technology available at the time, using a Duboscq colorimeter for measurement precision, and is credited for introducing colorimetry into modern biochemical analysis. [ 10 ]
Folin's research did not focus on creatinine as a renal function indicator. Since the precursors of creatinine are synthesized in the liver, [ 2 ] at this point in history, creatinine was considered indicative of liver function. [ 5 ] It was not until 1926 that Poul Kristian Brandt Rehberg suggested creatinine was a significant marker for renal function . [ 5 ]
The nonspecificity of Jaffe's reaction causes falsely elevated creatinine results in the presence of protein , glucose , acetoacetate , ascorbic acid , guanidine , acetone , cephalosporins , aminoglycosides (mainly streptomycin ), ketone bodies , α- keto acids , and other organic compounds. [ 1 ] [ 2 ] Ammonium is also an interferent; if the sample is plasma , care needs to be taken that ammonium heparin has not been used as an anticoagulant . [ 2 ] [ 13 ] [ 14 ] Nonspecificity is markedly decreased in urine samples since urine creatinine levels are much higher than blood and it generally does not contain significant levels of interfering chromogens. [ 2 ] [ 7 ]
The Jaffe reaction's nonspecificity remains an important issue. [ 1 ] Diabetes patients are a high-risk population to develop chronic kidney disease (CKD) and, therefore, interferences from glucose and acetoacetate are of particular importance. [ 15 ]
Artifacts such as hemolysis , lipemia , and icteremia can also affect accuracy. Hemolysis releases Jaffe-reacting chromogens and therefore will falsely increase results. [ 2 ] Lipemia and icteremia can inhibit optical readings and falsely decrease values. [ 2 ] The procedure has been developed over time with the intention to minimize these interferents. [ 1 ]
Before Jaffe, Neubauer described a similar precipitation reaction by mixing creatinine with zinc chloride (ZnCl 2 ) and performing a Weyl's test—the addition of SNP to NaOH and then incubating with acetic acid (CH 3 CO 2 H) to develop a color change. [ 5 ] Until Folin developed Jaffe's reaction into a clinical procedure, Neubauer's method was how creatinine was measured. As Folin's method evolved, various techniques were implemented to remove Jaffe-reacting substances, mostly protein, from the sample and increase specificity. [ 7 ] By the 1950s, precipitated aluminum silicate , called Lloyd's reagent, [ 16 ] was being used to remove protein from serum , further improving accuracy. [ 17 ] Fuller's earth was also used for protein-binding, [ 2 ] but the reference method until the 1980s was adsorption with Lloyd's reagent. [ 18 ] New concerns arose due to non-standardization of procedures; different labs were reading results at different endpoints. [ 5 ] This problem was resolved with the advent of automated analyzers in the 1960s and 1970s, which introduced a kinetic reading of results rather than a specific endpoint. [ 1 ] Kinetic Jaffe methods involve mixing serum with alkaline picrate and reading the rate of change in absorption spectrophotometrically at 520 nm. [ 17 ] This not only standardized the procedure, but also removed the need for sample deproteinization. [ 5 ] It also introduced two new problems—analyzers used an algorithmic compensation to correct for pseudochromogens, and calibrations were not yet standardized between instruments. [ 1 ] [ 5 ]
The 1980s saw several new technologies that promised to change the way creatinine testing was done. Enzymatic and ion-exchange methods provided better accuracy but had other drawbacks. [ 2 ] [ 5 ] [ 18 ] Enzymatic methods reduced some interferences but other new ones were discovered. [ 15 ] High-performance liquid chromatography , HPLC, was more sensitive and specific, and had become the new reference method endorsed by the American Association for Clinical Chemistry . [ 2 ] [ 15 ] [ 17 ] HPLC addressed the shortcomings of Jaffe-based methods, but was labor-intensive, expensive, and therefore impractical for routine analysis of the most frequently ordered renal analyte in medical labs. [ 2 ] Simple, easily automated and cost-effective, Jaffe-based methods have persisted into the 21st century, despite their imperfections. [ 1 ]
By 2006, isotope dilution mass spectrometry (IDMS) became the reference method. [ 1 ] [ 15 ] To improve the accuracy in creatinine testing, new standards were developed by the National Institute of Standards and Technology (NIST). [ 19 ] The College of American Pathologists (CAP) and the National Kidney Disease Education Program (NKDEP) collaborated with NIST to develop a new control reference called standard reference material 967 (SRM 967). [ 19 ] SRM 967 aims to standardize calibration of creatinine testing, including Jaffe methods. [ 19 ] Use of both IDMS and SRM 967 are currently recommended by the National Institutes of Health. [ 20 ] | https://en.wikipedia.org/wiki/Jaffe_reaction |
Jaguar is a computer software package used for ab initio quantum chemistry calculations for both gas and solution phases. [ 1 ] It is commercial software marketed by the company Schrödinger . The program was originated in research groups of Richard Friesner and William Goddard and was initially called PS-GVB (referring to the so-called pseudospectral generalized valence bond method that the program featured).
Jaguar is a component of two other Schrödinger products: Maestro, which provides the graphical user interface to Jaguar, and a QM/MM program QSite , which uses Jaguar as its quantum-chemical engine. The current version is Jaguar 10.4 (2020).
A distinctive feature of Jaguar is its use of the pseudospectral approximation. [ 2 ] This approximation can be applied to computationally expensive integral operations present in most quantum chemical calculations. As a result, calculations are faster with little loss in accuracy. [ 3 ] [ 4 ] [ 5 ]
The current version includes the following functionality: | https://en.wikipedia.org/wiki/Jaguar_(software) |
The Jahn–Teller effect (JT effect or JTE) is an important mechanism of spontaneous symmetry breaking in molecular and solid-state systems which has far-reaching consequences in different fields, and is responsible for a variety of phenomena in spectroscopy , stereochemistry , crystal chemistry , molecular and solid-state physics , and materials science . The effect is named for Hermann Arthur Jahn and Edward Teller , who first reported studies about it in 1937.
The Jahn–Teller effect , sometimes also referred to as Jahn–Teller distortion , describes the geometrical distortion of molecules and ions that results from certain electron configurations. The Jahn–Teller theorem essentially states that any non-linear molecule with a spatially degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the species. For a description of another type of geometrical distortion that occurs in crystals with substitutional impurities see article off-center ions .
The Jahn–Teller effect is most often encountered in octahedral complexes of the transition metals. [ 2 ] The phenomenon is very common in six-coordinate copper (II) complexes. [ 3 ] The d 9 electronic configuration of this ion gives three electrons in the two degenerate e g orbitals, leading to a doubly degenerate electronic ground state. Such complexes distort along one of the molecular fourfold axes (always labelled the z axis), which has the effect of removing the orbital and electronic degeneracies and lowering the overall energy. The distortion normally takes the form of elongating the bonds to the ligands lying along the z axis, but occasionally occurs as a shortening of these bonds instead (the Jahn–Teller theorem does not predict the direction of the distortion, only the presence of an unstable geometry). When such an elongation occurs, the effect is to lower the electrostatic repulsion between the electron-pair on the Lewis basic ligand and any electrons in orbitals with a z component, thus lowering the energy of the complex. The inversion centre is preserved after the distortion.
In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the e g orbitals. This situation arises in complexes with the configurations d 9 , low-spin d 7 or high-spin d 4 complexes, all of which have doubly degenerate ground states. In such compounds the e g orbitals involved in the degeneracy point directly at the ligands, so distortion can result in a large energetic stabilisation. Strictly speaking, the effect also occurs when there is a degeneracy due to the electrons in the t 2g orbitals ( i.e. configurations such as d 1 or d 2 , both of which are triply degenerate). In such cases, however, the effect is much less noticeable, because there is a much smaller lowering of repulsion on taking ligands further away from the t 2g orbitals, which do not point directly at the ligands (see the table below). The same is true in tetrahedral complexes (e.g. manganate : distortion is very subtle because there is less stabilisation to be gained because the ligands are not pointing directly at the orbitals.
The expected effects for octahedral coordination are given in the following table:
w: weak Jahn–Teller effect ( t 2g orbitals unevenly occupied)
s: strong Jahn–Teller effect expected ( e g orbitals unevenly occupied)
blank: no Jahn–Teller effect expected.
The Jahn–Teller effect is manifested in the UV-VIS absorbance spectra of some compounds, where it often causes splitting of bands. It is readily apparent in the structures of many copper(II) complexes. [ 4 ] Additional, detailed information about the anisotropy of such complexes and the nature of the ligand binding can be however obtained from the fine structure of the low-temperature electron spin resonance spectra.
The underlying cause of the Jahn–Teller effect is the presence of molecular orbitals that are both degenerate and open shell (i.e., incompletely occupied). This situation is not unique to coordination complexes and can be encountered in other areas of chemistry. In organic chemistry the phenomenon of antiaromaticity has the same cause and also often sees molecules distorting; as in the case of cyclobutadiene [ 5 ] and cyclooctatetraene (COT). [ 6 ]
The JT theorem can be stated in different forms, two of which are given here:
Alternatively and considerably shorter:
Spin-degeneracy was an exception in the original treatment and was later treated separately. [ 8 ]
The formal mathematical proof of the Jahn–Teller theorem rests heavily on symmetry arguments, more specifically the theory of molecular point groups . The argument of Jahn and Teller assumes no details about the electronic structure of the system. Jahn and Teller made no statement about the strength of the effect, which may be so small that it is immeasurable. Indeed, for electrons in non-bonding or weakly bonding molecular orbitals , the effect is expected to be weak. However, in many situations the JT effect is important.
Interest in the JTE increased after its first experimental verification. Various model systems were developed probing the degree of degeneracy and the type of symmetry. [ 9 ] These were solved partly analytically and partly numerically to obtain the shape of the pertinent potential energy surfaces (PES) and the energy levels for the nuclear motion on the JT-split PES. These energy levels are not vibrational energy levels in the traditional sense because of the intricate coupling to the electronic motion that occurs, and are better termed vibronic energy levels. The new field of ‘ vibronic coupling ’ or ‘vibronic coupling theory’ was born.
A further breakthrough occurred upon the advent of modern (" ab initio ") electronic structure calculations whereby the relevant parameters characterising JT systems can be reliably determined from first principles. Thus one could go beyond studies of model systems that explore the effect of parameter variations on the PES and vibronic energy levels; one could also go on beyond fitting these parameters to experimental data without clear knowledge about the significance of the fit. Instead, well-founded theoretical investigations became possible which greatly improved the insight into the phenomena at hand and into the details of the underlying mechanisms.
While recognizing the JTE distortion as a concrete example of the general spontaneous symmetry breaking mechanism, the exact degeneracy of the involved electronic state was identified as a non-essential ingredient for this symmetry breaking in polyatomic systems. Even systems that in the undistorted symmetric configuration present electronic states which are near in energy but not precisely degenerate, can show a similar tendency to distort. The distortions of these systems can be treated within the related theory of the pseudo Jahn–Teller effect (in the literature often referred to as "second-order JTE"). This mechanism is associated to the vibronic couplings between adiabatic PES separated by nonzero energy gaps across the configuration space: its inclusion extends the applicability of JT-related models to symmetry breaking in a far broader range of molecular and solid-state systems.
Chronology:
A given JT problem will have a particular point group symmetry , such as T d symmetry for magnetic impurity ions in semiconductors or I h symmetry for the fullerene C 60 . JT problems are conventionally classified using labels for the irreducible representations (irreps) that apply to the symmetry of the electronic and vibrational states. For example, E ⊗ e would refer to an electronic doublet state transforming as E coupled to a vibrational doublet state transforming as e.
In general, a vibrational mode transforming as Λ will couple to an electronic state transforming as Γ if the symmetric part of the Kronecker product [Γ ⊗ Γ] S contains Λ, unless Γ is a double group representation when the antisymmetric part {Γ ⊗ Γ} A is considered instead. Modes which do couple are said to be JT-active.
As an example, consider a doublet electronic state E in cubic symmetry. The symmetric part of E ⊗ E is A 1 + E. Therefore, the state E will couple to vibrational modes Q i {\displaystyle Q_{i}} transforming as a 1 and e. However, the a 1 modes will result in the same energy shift to all states and therefore do not contribute to any JT splitting. They can therefore be neglected. The result is an E ⊗ e JT effect. This JT effect is experienced by triangular molecules X 3 , tetrahedral molecules ML 4 , and octahedral molecules ML 6 when their electronic state has E symmetry.
Components of a given vibrational mode are also labelled according to their transformation properties. For example, the two components of an e mode are usually labelled Q θ {\displaystyle Q_{\theta }} and Q ϵ {\displaystyle Q_{\epsilon }} , which in octahedral symmetry transform as 3 z 2 − r 2 {\displaystyle 3z^{2}-r^{2}} and x 2 − y 2 {\displaystyle x^{2}-y^{2}} respectively.
Eigenvalues of the Hamiltonian of a polyatomic system define PESs as functions of normal modes Q i {\displaystyle Q_{i}} of the system (i.e. linear combinations of the nuclear displacements with specific symmetry properties). At the reference point of high symmetry, where the symmetry-induced degeneracy occurs, several of the eigenvalues coincide. By a detailed and laborious analysis, Jahn and Teller showed that – excepting linear molecules – there are always first-order terms in an expansion of the matrix elements of the Hamiltonian in terms of symmetry-lowering (in the language of group theory : non-totally symmetric) normal modes. These linear terms represent forces that distort the system along these coordinates and lift the degeneracy. The point of degeneracy can thus not be stationary, and the system distorts toward a stationary point of lower symmetry where stability can be attained.
Proof of the JT theorem follows from the theory of molecular symmetry ( point group theory). A less rigorous but more intuitive explanation is given in section § Coordination chemistry .
To arrive at a quantitative description of the JT effect, the forces appearing between the component wave functions are described by expanding the Hamiltonian in a power series in the Q i {\displaystyle Q_{i}} . Owing to the very nature of the degeneracy, the Hamiltonian takes the form of a matrix referring to the degenerate wave function components. A matrix element between states Ψ a {\displaystyle \Psi _{a}} and Ψ b {\displaystyle \Psi _{b}} generally reads as:
The expansion can be truncated after terms linear in the Q i {\displaystyle Q_{i}} , or extended to include terms quadratic (or higher) in the Q i {\displaystyle Q_{i}} .
The adiabatic potential energy surfaces (APES) are then obtained as the eigenvalues of this matrix. In the original paper it is proven that there are always linear terms in the expansion. It follows that the degeneracy of the wave function cannot correspond to a stable structure.
In mathematical terms, the APESs characterising the JT distortion arise as the eigenvalues of the potential energy matrix. Generally, the APESs take the characteristic appearance of a double cone, circular or elliptic, where the point of contact, i.e. degeneracy, denotes the high-symmetry configuration for which the JT theorem applies. For the above case of the linear E ⊗ e JT effect the situation is illustrated by the APES
displayed in the figure, with part cut away to reveal its shape, which is known as a Mexican Hat potential. Here, ω {\displaystyle \omega } is the frequency of the vibrational e mode, μ {\displaystyle \mu } is its mass and k {\displaystyle k} is a measure of the strength of the JT coupling.
The conical shape near the degeneracy at the origin makes it immediately clear that this point cannot be stationary , that is, the system is unstable against asymmetric distortions, which leads to a symmetry lowering. In this particular case there are infinitely many isoenergetic JT distortions. The Q i {\displaystyle Q_{i}} giving these distortions are arranged in a circle, as shown by the red curve in the figure. Quadratic coupling or cubic elastic terms lead to a warping along this "minimum energy path", replacing this infinite manifold by three equivalent potential minima and three equivalent saddle points. In other JT systems, linear coupling results in discrete minima.
The high symmetry of the double-cone topology of the linear E ⊗ e JT system directly reflects the high underlying symmetry. It is one of the earliest (if not the earliest) examples in the literature of a conical intersection of potential energy surfaces. Conical intersections have received wide attention in the literature starting in the 1990s and are now considered paradigms of nonadiabatic excited-state dynamics, with far-reaching consequences in molecular spectroscopy, photochemistry and photophysics. Some of these will be commented upon further below. In general, conical intersections are far less symmetric than depicted in the figure. They can be tilted and elliptical in shape etc., and also peaked and sloped intersections have been distinguished in the literature. Furthermore, for more than two degrees of freedom, they are not point-like structures but instead they are seams and complicated, curved hypersurfaces, also known as intersection space. The coordinate sub-space displayed in the figure is also known as a branching plane.
The characteristic shape of the JT-split APES has specific consequences for the nuclear dynamics, here considered in the fully quantum sense. For sufficiently strong JT coupling, the minimum points are sufficiently far (at least by a few vibrational energy quanta) below the JT intersection. Two different energy regimes are then to be distinguished, those of low and high energy.
As already stated above, the distinction of low and high energy regimes is valid only for sufficiently strong JT couplings, that is, when several or many vibrational energy quanta fit into the energy window between the conical intersection and the minimum of the lower JT-split APES. For the many cases of small to intermediate JT couplings this energy window and the corresponding adiabatic low-energy regime does not exist. Rather, the levels on both JT-split APES are intricately mixed for all energies and the nuclear motion always proceeds on both JT split APES simultaneously.
In 1965, Frank Ham [ 21 ] proposed that the dynamic JTE could reduce the expected values of observables associated with the orbital wavefunctions due to the superposition of several electronic states in the total vibronic wavefunction. This effect leads, for example, to a partial quenching of the spin–orbit interaction [ 21 ] [ 31 ] and allowed the results of previous Electron Paramagnetic Resonance (EPR) experiments to be explained.
In general, the result of an orbital operator acting on vibronic states can be replaced by an effective orbital operator acting on purely electronic states. In first order, the effective orbital operator equals the actual orbital operator multiplied by a constant, whose value is less than one, known as a first-order (Ham) reduction factor. For example, within a triplet T 1 electronic state, the spin–orbit coupling operator λ L . S {\displaystyle \lambda \mathbf {L} .\mathbf {S} } can be replaced by γ λ L . S {\displaystyle \gamma \lambda \mathbf {L} .\mathbf {S} } , where γ {\displaystyle \gamma } is a function of the strength of the JT coupling which varies from 1 in zero coupling to 0 in very strong coupling. Furthermore, when second-order perturbation corrections are included, additional terms are introduced involving additional numerical factors, known as second-order (Ham) reduction factors. These factors are zero when there is no JT coupling but can dominate over first-order terms in strong coupling, when the first-order effects have been significantly reduced. [ 9 ]
Reduction factors are particularly useful for describing experimental results, such as EPR and optical spectra, of paramagnetic impurities in semiconducting , dielectric , diamagnetic and ferrimagnetic hosts.
For a long time, applications of JT theory consisted mainly in parameter studies (model studies) where the APES and dynamical properties of JT systems have been investigated as functions on the system parameters such as coupling constants etc. Fits of these parameters to experimental data were often doubtful and inconclusive. The situation changed in the 1980s when efficient ab initio methods were developed and computational resources became powerful enough to allow for a reliable determination of these parameters from first principles. [ 32 ] Apart from wave function -based
techniques (which are sometimes considered genuinely ab initio in the literature) the advent of density functional theory (DFT) opened up new avenues to treat larger systems including solids. This allowed details of JT systems to be characterised and experimental findings to be reliably interpreted. It lies at the heart of most developments addressed in section § Applications .
Two different strategies are conceivable and have been used in the literature. One can
Naturally, the more accurate approach (2) may be limited to smaller systems, while the simpler approach (1) lends itself to studies of larger systems.
The JT distortion of small molecules (or molecular ions) is directly deduced from electronic structure calculations of their APES (through DFT and/or ab initio computations). These molecules / ions are often radicals, such as trimers of alkali atoms (Li 3 and Na 3 ), that have unpaired spins and in particular in (but not restricted to) doublet states. Besides the JTE in 2 E′ and 2 E″ states, also the pseudo JTE between an E state and a nearby A state may play a role. The JT distortion reduces the symmetry from D 3h to C 2v (see figure), and it depends on the details of the interactions whether the isosceles triangle has an acute or an obtuse-angled (such as Na 3 ) minimum energy structure. Natural extensions are systems like NO 3 and NH 3 + where a JT distortion has been documented in the literature for ground or excited electronic states.
A somewhat special role is played by tetrahedral systems like CH 4 + and P 4 + . Here threefold degenerate electronic states and vibrational modes come into play. Nevertheless, also twofold degeneracies continue to be important. The dynamics of Jahn-Teller distortion in CH 4 + has been characterized by transient X-ray absorption spectroscopy, revealing that symmetry breaking occurs within ten femtoseconds in this prototypical system. [ 33 ]
Among larger systems, a focus in the literature has been on benzene and its radical cation, as well as on their halo (especially fluoro) derivatives. Already in the early 1980s, a wealth of information emerged from the detailed analysis of experimental emission spectra of 1,3,5- trifluoro- and hexafluoro (and chloro) benzene radical cations. For the parent benzene cation one has to rely on photoelectron spectra with comparatively lower resolution because this species does not fluoresce (see also section § Spectroscopy and reactivity ). Rather detailed ab initio calculations have been carried out which
document the JT stabilization energies for the various (four) JT active modes and also quantify the moderate barriers for the JT pseudorotation.
Finally, a somewhat special role is played by systems with a fivefold symmetry axis like the cyclopentadienyl radical. Careful laser spectroscopic investigations have shed useful light on the JT interactions. In particular they reveal that the barrier to pseudorotation almost vanishes (the system is highly "fluxional") which can be attributed to the fact that the 2nd-order coupling terms vanish by symmetry and the leading higher-order terms are of 4th order.
The JTE is usually stronger where the electron density associated with the degenerate orbitals is more concentrated. This effect therefore plays a large role in determining the structure of transition metal complexes with active internal 3d orbitals.
The most iconic and prominent of the JT systems in coordination chemistry is probably the case of Cu(II) octahedral complexes. While in perfectly equivalent coordination, like a CuF 6 complex associated to a Cu(II) impurity in a cubic crystal like KMgF 3 , perfect octahedral (O h ) symmetry is expected. In fact a lower tetragonal symmetry is usually found experimentally. The origin of this JTE distortion it revealed by examining the electronic configuration of the undistorted complex. For an octahedral geometry, the five 3d orbitals partition into t 2g and e g orbitals (see diagram). These orbitals are occupied by nine electrons corresponding to the d 9 {\displaystyle d^{9}} electronic configuration of Cu(II). Thus, the t 2g shell is filled, and the e g shell contains 3 electrons. Overall the unpaired electron produces a 2 E g state, which is Jahn–Teller active. The third electron can occupy either of the orbitals comprising the e g shell: the mainly 3 z 2 − r 2 {\displaystyle 3z^{2}-r^{2}} orbital or the mainly x 2 − y 2 {\displaystyle x^{2}-y^{2}} orbital. If the electron occupies the mainly 3 z 2 − r 2 {\displaystyle 3z^{2}-r^{2}} level, which antibonding orbital the final geometry of the complex would be elongated as the axial ligands will be pushed away to reduce the global energy of the system. On the other hand, if the electron went into the mainly x 2 − y 2 {\displaystyle x^{2}-y^{2}} antibonding orbital the complex would distort into a compressed geometry. Experimentally elongated geometries are overwhelmingly observed and this fact has been attributed both to metal-ligand anharmonic interactions [ 15 ] and 3d-4s hybridisations. [ 34 ] Given that all the directions containing a fourfold axis are equivalent the distortion is equally likely to happen in any of these orientations. From the electronic point of view this means that the 3 z 2 − r 2 {\displaystyle 3z^{2}-r^{2}} and x 2 − y 2 {\displaystyle x^{2}-y^{2}} orbitals, that are degenerate and free to hybridise in the octahedral geometry, will mix to produce appropriate equivalent orbitals in each direction like 3 x 2 − r 2 {\displaystyle 3x^{2}-r^{2}} or 3 y 2 − r 2 {\displaystyle 3y^{2}-r^{2}} .
The JTE is not just restricted to Cu(II) octahedral complexes. There are many other configurations, involving changes both in the initial structure and electronic configuration of the metal that yield degenerate states and, thus, JTE. However, the amount of distortion and stabilisation energy of the effect is strongly dependent on the particular case. In octahedral Cu(II), the JTE is particularly strong because
In other configurations involving π or δ bonding, like for example when the degenerate state is associated to the t 2g orbitals of an octahedral configuration, the distortion and stabilisation energies are usually much smaller and the possibility of not observing the distortion due to dynamic JT effects is much higher. Similarly for rare-earth ions where covalency is very small, the distortions associated to the JTE are usually very weak.
Importantly, the JTE is associated with strict degeneracy in the electronic subsystem and so it cannot appear in systems without this property. For example, the JTE is often associated to cases like quasi-octahedral CuX 2 Y 4 complexes where the distances to X and Y ligands are clearly different. However, the intrinsic symmetry of these complexes is already tetragonal and no degenerate e g orbital exists, having split into a 1g (mainly 3 z 2 − r 2 {\displaystyle 3z^{2}-r^{2}} ) and b 1g (mainly x 2 − y 2 {\displaystyle x^{2}-y^{2}} ) orbitals due to the different electronic interactions with axial X ligands and equatorial Y ligands . In this and other similar cases some remaining vibronic effects related to the JTE are still present but are quenched with respect to the case with degeneracy due to the splitting of the orbitals.
From spectra with rotational resolution, moments of inertia and hence bond lengths and angles can be determined "directly" (at least in principle). From less well-resolved spectra one can still determine important quantities like JT stabilization energies and energy barriers (e.g. to pseudorotation). However, in the whole spectral intensity distribution P ( E ) {\displaystyle P(E)} of an electronic transition more information is encoded. It has been used to decide on the presence (or absence) of the geometric phase which is accumulated during the pseudorotational motion around the JT (or other type of) conical intersection. Prominent examples of either type are the ground (X) or an excited (B) state of Na 3 . The Fourier transform of P ( E ) {\displaystyle P(E)} , the so-called autocorrelation function C ( t ) {\displaystyle C(t)} reflects the motion of the wavepacket after an optical (= vertical) transition to the APES of the final electronic state. Typically it will move on the timescale of a vibrational period which is (for small molecules) of the order of 5–50 fs, i.e. ultrafast. Besides a nearly periodic motion, mode–mode interactions with very irregular (also chaotic) behaviour and spreading of the wavepacket may also occur. Near a conical intersection this will be accompanied/complemented by nonradiative transitions (termed internal conversion) to other APESs occurring on the same ultrafast time scale.
For the JT case the situation is somewhat special, as compared to a general conical intersection, because the different JT potential sheets are symmetry-related to each other and have (exactly or nearly) the same energy minimum. The "transition" between them is thus more oscillatory than one would normally expect, and their time-averaged populations are close to 1/2. For a more typical scenario a more general conical intersection is "required".
The JT effect still comes into play, namely in combination with a different nearby, in general non-degenerate electronic state. The result is a pseudo Jahn–Teller effect , for example, of an E state interacting with an A state. This situation is common in JT systems, just as interactions between two nondegenerate electronic states are common for non-JT systems. Examples are excited electronic states of NH 3 + and the benzene radical cation. Here, crossings between the E and A state APESs amount to triple intersections, which are associated with very complex spectral features (dense line structures and diffuse spectral envelopes under low resolution). The population transfer between the states is also ultrafast, so fast that fluorescence (proceeding on a nanosecond time scale) cannot compete. This helps to understand why the benzene cation, like many other organic radical cation, does not fluoresce.
To be sure, photochemical reactivity emerges when the internal conversion makes the system explore the nuclear configuration space such that new chemical species are formed. There is a plethora of femtosecond pump-probe spectroscopic techniques to reveal details of these processes occurring, for example, in the process of vision.
As proposed originally by Landau [ 35 ] free electrons in a solid, introduced for example by doping or irradiation, can interact with the vibrations of the lattice to form a localized quasi-particle known as a polaron . Strongly localized polarons (also called Holstein polarons) can condensate around high-symmetry sites of the lattice with electrons or holes occupying local degenerate orbitals that experience the JTE. These Jahn–Teller polarons break both translational and point group symmetries of the lattice where they are found and have been attributed important roles in effects like colossal magnetoresistance and superconductivity .
Paramagnetic impurities in semiconducting , dielectric , diamagnetic and ferrimagnetic hosts can all be described using a JT model. For example, these models were used extensively in the 1980s and 1990s to describe ions of Cr, V and Ti substituting for Ga in GaAs and GaP.
The fullerene C 60 can form solid compounds with alkali metals known as fullerides . Cs 3 C 60 can be superconducting at temperatures up to 38K under applied pressure, [ 36 ] whereas compounds of the form A 4 C 60 are insulating (as reviewed by Gunnarsson [ 37 ] ). JT effects both within the C 60 molecules (intramolecular) and between C 60 molecules (intermolecular) play a part in the mechanisms behind various observed properties in these systems. For example, they could mean that the Migdal–Eliashberg treatment of superconductivity breaks down. Also, the fullerides can form a so-called new state of matter known as a Jahn–Teller metal, where localised electrons coexist with metallicity and JT distortions on the C 60 molecules persist. [ 38 ]
The JTE is usually associated with degeneracies that are well localised in space, like those occurring in a small molecule or associated to an isolated transition metal complex. However, in many periodic high-symmetry solid-state systems, like perovskites, some crystalline sites allow for electronic degeneracy giving rise under adequate compositions to lattices of JT-active centers. This can produce a cooperative JTE, where global distortions of the crystal occur due to local degeneracies.
In order to determine the final electronic and geometric structure of a cooperative JT system, it is necessary to take into account both the local distortions and the interaction between the different sites, which will take such form necessary to minimise the global energy of the crystal.
While works on the cooperative JTE started in the late fifties, [ 39 ] [ 40 ] it was in 1960 that Kanamori [ 41 ] published the first work on the cooperative JTE where many important elements present in the modern theory for this effect were introduced. This included the use of pseudospin notation to discuss orbital ordering, and discussions of the importance of the JTE to discuss magnetism, the competition of this effect with the spin–orbit coupling and the coupling of the distortions with the strain of the lattice. This point was later stressed in the review by Gehring and Gehring [ 42 ] as being the key element to establish long-range order between the distortions in the lattice. An important part of the modern theory of the cooperative JTE, [ 43 ] can lead to structural phase transitions .
Many cooperative JT systems would be expected to be metals from band theory, as to produce them, a degenerate orbital has to be partially filled and the associated band would be metallic. However, under the perturbation of the symmetry-breaking distortion associated to the cooperative JTE, the degeneracies in the electronic structure are destroyed and the ground state of these systems is often found to be insulating (see e.g. [ 44 ] ). In many important cases like the parent compound for colossal magnetoresistance perovskites, LaMnO 3 , an increase of temperature leads to disorder in the distortions which lowers the band splitting due to the cooperative JTE, thus triggering a metal–insulator transition.
In modern solid-state physics, it is common to classify systems according to the kind of degrees of freedom they have available, like electron (metals) or spin (magnetism). In crystals that can display the JTE, and before this effect is realised by symmetry-breaking distortions, it is found that there exists an orbital degree of freedom consisting of how electrons occupy the local degenerate orbitals. As initially discussed by Kugel and Khomskii, [ 45 ] not all configurations are equivalent. The key is the relative orientation of these occupied orbital, in the same way that spin orientation is important in magnetic systems, and the ground state can only be realised for some particular orbital pattern. Both this pattern and the effect giving rise to this phenomenon is usually denominated orbital-ordering.
In order to predict the orbital-ordering pattern, Kugel and Khomskii used a particularisation of the Hubbard model . In particular they established how superexchange interactions, usually described by the Anderson–Kanamori–Goodenough rules, change in the presence of degenerate orbitals. Their model, using a pseudospin representation for the local orbitals, leads to a Heisenberg-like model in which the ground state is a combination of orbital and spin patterns. Using this model it can be shown, for example, that the origin of the unusual ground insulating ferromagnetic state of a solid like K 2 CuF 4 can be traced to its orbital ordering.
Even when starting from a relatively high-symmetry structure the combined effect of exchange interactions, spin–orbit coupling, orbital-ordering and crystal deformations activated by the JTE can lead to very low symmetry magnetic patterns with specific properties. For example, in CsCuCl 3 an incommensurable helicoidal pattern appears both for the orbitals and the distortions along the z {\displaystyle z} -axis. Moreover, many of these compounds show complex phase diagrams when varying temperature or pressure. | https://en.wikipedia.org/wiki/Jahn–Teller_effect |
Jai Pal Mittal is an Indian scientist, DAE Raja Ramanna Fellow of Bhabha Atomic Research Centre and Distinguished Professor of Indian Institute of Technology, Mumbai , the National Academy of Sciences, India and the University of Pune . [ 1 ] [ 2 ] He is known for his researches in the fields of photochemistry and radiation chemistry . [ 3 ] He was honoured by the Government of India in 2003 with Padma Shri , the fourth highest Indian civilian award. [ 4 ]
Jai Pal Mittal was born on 21 September 1940 in Meerut in the Indian state of Uttar Pradesh . [ 1 ] He completed his graduate (BSc) and master's studies (MSc) in chemistry from the Agra University [ 2 ] [ 3 ] and migrated to Mumbai in 1959, looking for career opportunities. [ 1 ] He joined the Training School of Atomic Energy Establishment, erstwhile Bhabha Atomic Research Centre and did a one-year course after which he moved to USA to join the Department of Radiation Chemistry of the University of Notre Dame , Indiana. [ 1 ] [ 2 ] [ 3 ] He completed his doctoral studies (PhD) in 1967, under the guidance of A. A. Lamola and W. H. Hamill. [ 1 ] Receiving an invitation from Willard Libby , the 1960 Nobel laureate in Chemistry, to assist him, Mittal did his post doctoral research, for over a year, at the Radiation and Nuclear Chemistry laboratory of the University of California . [ 1 ] [ 2 ] [ 3 ]
In 1969, Mittal returned to India to start his career as a Pool Officer at the Bhabha Atomic Research Centre (BARC) and started working in the field of photochemistry. [ 1 ] Two years later, in 1971, he got an opportunity to work with Professor E. Hayon at the United States Army Natick Soldier Research, Development and Engineering Center and worked there for one year. [ 1 ] On his return to India in 1972, he formed a research group at BARC for research in photochemistry and radiation chemistry. [ 1 ] During this period, he organized the first national symposium in Thiruvananthapuram , National Symposium on Fast Reaction Chemistry and Techniques . [ 1 ]
Mittal continued at BARC to become the Director of Chemistry and Isotope Group and the DAE Raja Ramanna Fellow of the institution. [ 2 ] He also holds the position of M. N. Saha Distinguished Professor of the National Academy of Sciences, India [ 5 ] and the post of a Distinguished Professor at the University of Pune and the Indian Institute of Technology, Mumbai . [ 2 ] During his tenure at BARC, he is known to have contributed for the establishment of a nanosecond LINAC based pulse radiolysis system at BARC and promoted the nano, pico and femtosecond pump and probe techniques to study the chemical dynamics. [ 2 ] He is reported to have initiated a new school of research in Radiation Chemistry and Photochemistry in India [ 5 ] and his group was successful in isotopic enrichment of hydrogen, carbon and uranium isotopes. [ 2 ] His research findings have been recorded by way of over 300 scientific papers, [ 2 ] [ 3 ] published in peer reviewed journals and ResearchGate , an online scientific data repository, have listed 250 of them. [ 5 ] He has also mentored many students in their doctoral studies. [ 2 ]
Mittal has been associated with the Board of Research in Nuclear Sciences as a chairman of many of its basic sciences committees. He is a former president of the Indian Society of Radiation and Photochem Sciences (1997-2001), the National Academy of Sciences, India (2003–04) [ 3 ] [ 6 ] and the Asian Photochemistry Association (2003- 2008). [ 2 ] He has also served the Indian National Science Academy as a council member (1998-2000) and as an additional member (2005–06). [ 2 ] He serves as the president of the Asian and Oceanian Photochemistry Association [ 7 ] and is a member of the education council of the University of Allahabad . [ 8 ] He is a life member of the Indian Chemical Society [ 3 ] where has also been a past president. [ 2 ]
Mittal lives in Navi Mumbai in Maharashtra [ 2 ] and continues attending seminars and conferences to deliver keynote addresses. [ 9 ]
Jai Pal Mittal is an elected fellow the Indian National Science Academy , National Academy of Sciences, India , [ 10 ] The World Academy of Sciences , the Indian Academy of Sciences [ 11 ] and the Maharashtra Academy of Sciences . [ 1 ] [ 2 ] He is a recipient of two awards, Professor T. R. Seshadri 70th Birthday Commemoration Medal in 1994 and the Golden Jubilee Commemoration Medal in 2001, from the Indian National Science Academy. [ 2 ] A winner of 1964 Fulbright scholarship and 2002 Humboldt Research Award, Mittal has received the Senior JSPS Award, National Academy of Sciences, India N. R. Dhar Memorial Medal, Goyal Gold Medal and the Indian Science Congress Association Platinum Jubilee Award. [ 2 ] The Government of India awarded him the civilian award of Padma Shri in 2003. [ 2 ] [ 3 ] | https://en.wikipedia.org/wiki/Jai_Pal_Mittal |
Jakarta EE , formerly Java Platform, Enterprise Edition ( Java EE ) and Java 2 Platform, Enterprise Edition ( J2EE ), is a set of specifications, extending Java SE [ 1 ] with specifications for enterprise features such as distributed computing and web services . [ 2 ] Jakarta EE applications are run on reference runtimes , which can be microservices or application servers , which handle transactions, security, scalability, concurrency and management of the components they are deploying.
Jakarta EE is defined by its specification . The specification defines APIs (application programming interface) and their interactions. As with other Java Community Process specifications, providers must meet certain conformance requirements in order to declare their products as Jakarta EE compliant .
Examples of contexts in which Jakarta EE referencing runtimes are used are: e-commerce , accounting , banking information systems .
The platform created by Sun Microsystems was known as Java 2 Platform, Enterprise Edition or J2EE from version 1.2, until the name was changed to Java Platform, Enterprise Edition or Java EE in version 1.5.
After Sun was acquired in 2009 , Java EE was maintained by Oracle under the Java Community Process . On September 12, 2017, Oracle Corporation announced that it would submit Java EE to the Eclipse Foundation . [ 3 ] The Eclipse top-level project has been named Eclipse Enterprise for Java (EE4J). [ 4 ] The Eclipse Foundation could not agree with Oracle over the use of javax and Java trademarks. [ 5 ] Oracle owns the trademark for the name "Java" and the platform was renamed from Java EE to Jakarta EE. [ 6 ] [ 7 ] The name refers to the largest city on the island of Java and also the capital of Indonesia, Jakarta . [ 8 ] The name should not be confused with the former Jakarta Project which fostered a number of current and former Java projects at the Apache Software Foundation .
Jakarta EE includes several specifications that serve different purposes, like generating web pages, reading and writing from a database in a transactional way, managing distributed queues.
The Jakarta EE APIs include several technologies that extend the functionality of the base Java SE APIs , such as Jakarta Enterprise Beans , connectors , servlets , Jakarta Server Pages and several web service technologies.
In an attempt to limit the footprint of web containers, both in physical and in conceptual terms, the web profile was created, a subset of the Jakarta EE specifications. The Jakarta EE web profile comprises the following:
Although by definition all Jakarta EE implementations provide the same base level of technologies (namely, the Jakarta EE spec and the associated APIs), they can differ considerably with respect to extra features (like connectors , clustering , fault tolerance , high availability , security , etc.), installed size, memory footprint , startup time, etc.
The code sample shown below demonstrates how various technologies in Java EE 7 are used together to build a web form for editing a user.
In Jakarta EE a (web) UI can be built using Jakarta Servlet , Jakarta Server Pages ( JSP ), or Jakarta Faces ( JSF ) with Facelets . The example below uses Faces and Facelets . Not explicitly shown is that the input components use the Jakarta EE Bean Validation API under the covers to validate constraints.
To assist the view, Jakarta EE uses a concept called a "Backing Bean". The example below uses Contexts and Dependency Injection (CDI) and Jakarta Enterprise Beans ( EJB ).
To implement business logic, Jakarta Enterprise Beans ( EJB ) is the dedicated technology in Jakarta EE. For the actual persistence, JDBC or Jakarta Persistence (JPA) can be used. The example below uses EJB and JPA. Not explicitly shown is that JTA is used under the covers by EJB to control transactional behavior.
For defining entity/model classes Jakarta EE provides the Jakarta Persistence ( JPA ), and for expressing constraints on those entities it provides the Bean Validation API. The example below uses both these technologies. | https://en.wikipedia.org/wiki/Jakarta_EE |
A Jakarta EE application (formerly also called Java EE or J2EE application) is any deployable unit of Jakarta EE functionality. This can be a single Jakarta EE module or a group of modules packaged into an EAR file along with a Jakarta EE application deployment descriptor . Jakarta EE applications are typically engineered to be distributed across multiple computing tiers.
Enterprise applications can consist of combinations of the following:
This computing article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jakarta_EE_application |
Jakob Steiner (18 March 1796 – 1 April 1863) was a Swiss mathematician who worked primarily in geometry .
Steiner was born in the village of Utzenstorf , Canton of Bern . At 18, he became a pupil of Heinrich Pestalozzi and afterwards studied at Heidelberg . Then, he went to Berlin, earning a livelihood there, as in Heidelberg, by tutoring. Here he became acquainted with A. L. Crelle , who, encouraged by his ability and by that of Niels Henrik Abel , then also staying at Berlin, founded his famous Journal (1826).
After Steiner's publication (1832) of his Systematische Entwickelungen he received, through Carl Gustav Jacob Jacobi , who was then professor at Königsberg University , and earned an honorary degree there; and through the influence of Jacobi and of the brothers Alexander and Wilhelm von Humboldt a new chair of geometry was founded for him at Berlin (1834). This he occupied until his death in Bern on 1 April 1863.
He was described by Thomas Hirst as follows:
Steiner's mathematical work was mainly confined to geometry . This he treated synthetically, to the total exclusion of analysis, which he hated, [ 1 ] and he is said to have considered it a disgrace to synthetic geometry if equal or higher results were obtained by analytical geometry methods. In his own field he surpassed all his contemporaries. His investigations are distinguished by their great generality, by the fertility of his resources, and by the rigour in his proofs. He has been considered the greatest pure geometer since Apollonius of Perga .
In his Systematische Entwickelung der Abhängigkeit geometrischer Gestalten von einander he laid the foundation of modern synthetic geometry. In projective geometry even parallel lines have a point in common: a point at infinity . Thus two points determine a line and two lines determine a point. The symmetry of point and line is expressed as projective duality . Starting with perspectivities , the transformations of projective geometry are formed by composition , producing projectivities . Steiner identified sets preserved by projectivities such as a projective range and pencils . He is particularly remembered for his approach to a conic section by way of projectivity called the Steiner conic .
In a second little volume, Die geometrischen Constructionen ausgeführt mittels der geraden Linie und eines festen Kreises (1833), republished in 1895 by Ottingen, he shows, what had been already suggested by J. V. Poncelet , how all problems of the second order can be solved by aid of the straight edge alone without the use of compasses, as soon as one circle is given on the drawing-paper. He also wrote "Vorlesungen über synthetische Geometrie" , published posthumously at Leipzig by C. F. Geiser and H. Schroeter in 1867; a third edition by R. Sturm was published in 1887–1898.
Other geometric results by Steiner include development of a formula for the partitioning of space by planes (the maximal number of parts created by n planes), several theorems about the famous Steiner's chain of tangential circles, and a proof of the isoperimetric theorem (later a flaw was found in the proof, but was corrected by Weierstrass ).
The rest of Steiner's writings are found in numerous papers mostly published in Crelle's Journal , the first volume of which contains his first four papers. The most important are those relating to algebraic curves and surfaces, especially the short paper Allgemeine Eigenschaften algebraischer Curven . This contains only results, and there is no indication of the method by which they were obtained, so that, according to O. Hesse , they are, like Fermat 's theorems, riddles to the present and future generations. Eminent analysts succeeded in proving some of the theorems, but it was reserved to Luigi Cremona to prove them all, and that by a uniform synthetic method, in his book on algebraic curves.
Other important investigations relate to maxima and minima . Starting from simple elementary propositions, Steiner advances to the solution of problems which analytically require the calculus of variations , but which at the time altogether surpassed the powers of that calculus. Connected with this is the paper Vom Krümmungsschwerpuncte ebener Curven , which contains numerous properties of pedals and roulettes , especially of their areas.
Steiner also made a small but important contribution to combinatorics . In 1853, Steiner published a two-page article in Crelle's Journal on what nowadays is called Steiner systems , a basic kind of block design .
His oldest papers and manuscripts (1823–1826) were published by his admirer Fritz Bützberger on the request of the Bernese Society for Natural Scientists. [ 2 ] | https://en.wikipedia.org/wiki/Jakob_Steiner |
Roman Jakobson defined six functions of language (or communication functions ), according to which an effective act of verbal communication can be described. [ 2 ] Each of the functions has an associated factor. For this work, Jakobson was influenced by Karl Bühler 's organon model , to which he added the poetic, phatic and metalingual functions. | https://en.wikipedia.org/wiki/Jakobson's_functions_of_language |
Jalayagnam or Jala Yagnam , (water worship), is a water management program in India. It has been implemented by Chief Minister of Andhra Pradesh , India, Dr. Y. S. Rajasekhara Reddy as an election promise to the farmers of the state to bring 8.2 million acres (8.2 million acres) under irrigation in five years. Y.S.R has taken required approvals from central government and NGTL. Also other required permissions for all the projects before he died. Like Site clearance, environmental clearance, R & R clearance, wildlife sanctuary clearance, forest clearance and technical advisory committee clearance. By the time he supposed to execute projects on phase manner, Y.S.R died in accident. Subsequently there was other issues like state bifurcation came to high intensity, subsequent Chief Ministers failed to give priority for Jalayagnam. [ 1 ]
This project accords the highest priority for the development of irrigation infrastructure, particularly in backward and drought prone areas by taking up this program in a big way. Jala Yagnam includes a number of irrigation projects by construction of reservoirs and lift irrigation systems for lifting water from major rivers, particularly from Godavari , to provide immediate irrigation benefits.
The Jala Yagnam program was to complete 32 major and 17 medium irrigation projects at a cost of Rs. 650 billion to provide irrigation to an extent of 7.1 million acres besides stabilization of an existing ayacut of 2,132,000 acres while providing drinking water to a population of 12 million and generating power to the tune of 1700 MW. Eight of these projects were to be completed before the kharif season of 2006.
The project requires the construction of 78 dams and is expected to displace significant numbers of people whose villages will be submerged. The irrigation development was almost stagnant for the last decade and the previous governments concentrated on hi-tech and neglected the agricultural sector, on which approximately 70% of the population depends. The fact that 26% of the population, mostly in rural areas, was living below the poverty line made Dr. Reddy wonder whether science and technology had made a significant difference in the quality of life in rural areas, compared to towns and cities. Also the suicides of many farmers from the state made Dr. Y. S. Rajasekhara Reddy give more significance to the irrigation sector. Having recognized the importance of the agricultural sector for faster economic development, Dr. Y. S. Rajasekhara Reddy started concentrating largely on its development and introduced several schemes for the benefit of the farmers, one of which is the Jala Yagnam project.
In the past 50 years, a total ayacut of 6.5 million acres was developed in the state. Jala Yagnam is expected to double the area under irrigation. It would constitute a major component of the Central government programme National Irrigation Mission's (NIM) target of bringing ten million hectares of land (25 million acres) in the country under the plough. The largest allocation of funds, during 2004-09, is for irrigation, as the government considers irrigation an important growth engine.
The most expensive of the projects are the lift irrigation projects intended to irrigate the dry Telangana region and supply water to the Anantapur - Ongole - Mahabubnagar area which is "turning into a desert". With the land level being 300 metres above the water level, lift irrigation is supposed to be the only way to take water to the dry region. Currently, 3,000 tmc water from Godavari is washed into the sea, as the land is at a higher elevation.
For the first time in the post-independence era, the Congress government took up linking of Godavari and Krishna by constructing the Indira Sagar Project and Rajiv Sagar project across the River Godavari. By executing projects like Rajiv Sagar, Indira Sagar flood flow canal, SRSP Phase-II and so on, 2.1 million acres of parched land in Telangana region would be made fertile.
This is the link which redirects to the map in which all the Jalayagnam projects are seen and also projects which have been
already finished by Andhra Pradesh government. Details such as estimated and actual costs of Jalayagnam projects are also included. For completed projects, details like district they are in and rivers they are on are also included.
Jalayagnam and other completed projects'map
The documents obtained from Right to Information Act of India indicates that show the irregularities that were committed range from violation of the common tender document to illegally made excessive payments for the works done and fraudulently claimed to have been done. | https://en.wikipedia.org/wiki/Jalayagnam |
The Jamaica Society of Energy Engineers (JSEE) is a newly formed public non-profit organization with a mandate to promote the conscientious utilization of energy resources in Jamaica . The JSEE formation was initially spurred by the need for a professional entity to provide and oversee local training and certification of Energy Auditors and Managers.
The JSEE is now a chapter [ 1 ] of the Association of Energy Engineers (AEE), [ 2 ] which is the world-wide certifying body for all energy engineers .
The formation of the society was spearheaded by the Computing and Engineering Entrepreneurial Centre, [ 3 ] at the University of Technology (UTech) and was officially launched [ 4 ] at the Technology Innovation Centre, UTech on 27 February 2009.
The society's objectives are to promote energy matters in organizations, corporate with industries and organizations to provide energy solutions [ buzzword ] , certify energy professionals and provide career guidance for students at the secondary and tertiary levels.
As part of the Government of Jamaica ’s (GOJ) expressed desire to promote the implementation of energy efficiency and conservation practices, the GOJ through the Development Bank of Jamaica (DBJ) made available J$1 Billion to be lent to Small and Medium Size Enterprises (SME’s). The Project named the “DBJ-PetroCaribe Energy Line of Credit for SME” [ 5 ] will be distributed by Approved Financial Institutions (AFIs) (Commercial Banks, Credit Unions and P.C. Banks) to SME members after completing an Energy Audit done by an approved Auditor from the Petroleum Corporation of Jamaica .
The University of Technology, Jamaica was invited to be a partner in the project to establish the Jamaica Society of Energy Engineers and to train persons as Certified Energy Managers [ 6 ] expected to do the audits on the SME. The other members of the partnership are Development Bank of Jamaica (DBJ), [ 7 ] Jamaica Trade and Invest (JTI), [ 8 ] and Petroleum Corporation of Jamaica (PCJ). | https://en.wikipedia.org/wiki/Jamaica_Society_of_Energy_Engineers |
Jamaica ginger extract, known in the United States by the slang name Jake , was a late 19th-century patent medicine that provided a convenient way to obtain alcohol during the era of Prohibition , since it contained approximately 70% to 80% ethanol by weight. [ 1 ] [ 2 ] In the 1930s, a large number of users of Jamaica ginger were afflicted with a paralysis of the hands and feet that quickly became known as Jamaica ginger paralysis or jake paralysis. [ 1 ] [ 2 ]
While Jamaica ginger was essentially an infusion of ginger, the US government required solids to be added with the intention of making it less palatable as a way to obtain alcohol legally. The solids expected to be added were particles of ginger root, which made the "medicine" unpalatable. Manufacturers sought solids which impaired the taste less; tricresyl phosphate was used, which the producers later found to be a potent neurotoxin; adulterated Jake is estimated to have caused 30,000 to 50,000 people to lose function in their limbs. Trust in Jamaica Ginger was lost, and its production was discontinued. [ 3 ]
Since the 1860s, Jamaica ginger had been widely sold at drug stores and roadside stands in two-ounce (57 g) bottles. [ 1 ] [ 2 ] [ 4 ] In small doses, mixed with water, it was used as a remedy for headaches , upper respiratory infections , menstrual disorders , and intestinal gas . [ 1 ] [ 2 ] Despite its strong ginger flavour, it was popular as an alcoholic beverage in dry counties in the United States, where it was a convenient and legal method of obtaining alcohol. [ 1 ] It was often mixed with a soft drink to improve the taste. [ 1 ]
When Prohibition was enacted in 1920, sale of alcohol became illegal nationwide, prompting consumers to search for substitutes. [ 5 ] Patent medicines with a high alcohol percentage, such as Jamaica ginger, became obvious choices, as they were legal and available over the counter without prescriptions. By 1921, the United States government made the original formulation of Jamaica ginger prescription-only. [ 6 ] Only a fluid extract version defined in the United States Pharmacopeia , with a high content of bitter-tasting ginger oleoresin , remained available in stores. [ 1 ] [ 6 ] Because of the taste, it was classified as nonpotable, and was therefore legal to sell despite the alcohol content. [ 1 ]
United States Department of Agriculture agents audited Jamaica ginger manufacturers by boiling samples and weighing the resulting solids, to make sure their products contained sufficiently high quantities of the bitter-tasting ginger. [ 4 ] To make their products more palatable, manufacturers of Jamaica ginger began to illegally replace the ginger oleoresin with cheaper ingredients like molasses , glycerin , and castor oil , cutting costs and significantly diminishing the unpleasant ginger flavor. [ 1 ] [ 4 ]
When the price of castor oil increased in the latter portion of the 1920s, Harry Gross, president of Hub Products Corporation, sought an alternative additive for his Jamaica ginger formula. He discarded ethylene glycol and diethylene glycol as being too volatile , eventually selecting a mixture containing triorthocresyl phosphate (TOCP), a plasticizer used in lacquers and paint finishing . Gross was advised by the manufacturer of the mixture, Celluloid Corporation, that it was non-toxic. [ 4 ] [ 7 ]
TOCP was originally thought to be non-toxic; however, it was later determined to be a neurotoxin that causes axonal damage to the nerve cells in the nervous system of human beings, especially those located in the spinal cord . The resulting type of paralysis is now referred to as organophosphate-induced delayed neuropathy , or OPIDN. [ 8 ]
In 1930, large numbers of Jake users began to find they were unable to use their hands and feet. [ 9 ] Some victims could walk, but they had no control over the muscles which would normally have enabled them to point their toes upward. Therefore, they would raise their feet high with the toes flopping downward, which would touch the pavement first followed by their heels. The toe first, heel second pattern made a distinctive "tap-click, tap-click" sound as they walked. This very peculiar gait became known as the jake walk and the jake dance and those afflicted were said [ 10 ] to have jake leg, jake foot, or jake paralysis. Additionally, the calves of the legs would soften and hang down and the muscles between the thumbs and fingers would atrophy .
Within a few months, the TOCP-adulterated Jake was identified as the cause of the paralysis, [ 11 ] and the contaminated Jake was recovered. But by that time, it was too late for many victims. Some did recover full, or partial, use of their limbs. But for most, the loss was permanent. The total number of victims was never accurately determined, but is frequently quoted as between 30,000 and 50,000. Many victims were immigrants to the United States, and most were poor, with little political or social influence. The victims received very little assistance. [ citation needed ] Harry Gross and his part-owner of Boston-Hub Products, Max Reisman, were ultimately fined $1,000 each and given a two-year suspended jail sentence. [ 11 ]
Several blues songs on the subject were recorded in the early 1930s, such as "Jake Walk Papa" by Asa Martin , and "Jake Liquor Blues" by Ishman Bracey . [ 7 ]
Although this incident became well known, [ citation needed ] later cases of organophosphate poisoning occurred in Germany, Spain, Italy, and, on a large scale, in Morocco in 1959, where cooking oil adulterated with jet engine lubricant from an American airbase led to paralysis in approximately 10,000 victims, and caused an international incident. [ 12 ]
Songs were recorded at the time about "jake" and its effects; in a variety of musical styles, including blues and country . Several have been included on the compilation albums Jake Walk Blues (1977, 14 songs) [ 13 ] and Jake Leg Blues (1994, 16 songs) [ 14 ] [ 15 ] There is a marked but unsurprising duplication of songs between those albums. In some cases, different artists used the same title for different songs. The songs on one or both of those albums are, in alphabetic order by title:
Other musical references include: | https://en.wikipedia.org/wiki/Jamaica_ginger |
James A. Ibers was the Charles E. and Emma H. Morrison Professor of Chemistry before becoming an emeritus professor of chemistry at Northwestern University upon retirement. He is recognized for contributions to inorganic chemistry, especially in the areas of coordination chemistry, bio-inorganic chemistry, solid state synthesis and X-ray crystallography . Ibers passed on December 14, 2021, at the age of 91. [ 1 ]
Ibers received his B.S. and Ph.D. degrees at California Institute of Technology . His thesis, awarded in 1954, was done under the direction of Verner F. Schomoker and James H. Sturdivant.
After graduation, Ibers accepted a staff scientist position at Shell Development Company and later Brookhaven National Laboratory . Starting in 1965 until his retirement, Ibers was a professor of chemistry at Northwestern University. His broad research interests included many aspects of organometallic, [ 2 ] bioinorganic, [ 3 ] and solid state chemistry,. [ 4 ] Ibers was a noted pioneer in the applications of X-Ray Crystallography to chemical problems and issues associated with inorganic bonding. | https://en.wikipedia.org/wiki/James_A._Ibers |
James A. Rafferty , Vice President, Officers' Committee member, [ 2 ] Director, and member of the executive committee of Union Carbide , was an important figure in the petrochemical industry . Rafferty guided Union Carbide's effort in developing the new industry of synthetic aliphatic chemicals (aliphatic compounds are one of the two main branches within organic chemistry) and was instrumental in the development of the liquid oxygen industry. [ 3 ] [ 4 ] Rafferty directed Union Carbide's collaboration with the United States government for the Manhattan Project [ 5 ] [ 6 ] and with the War Production Board for the synthetic rubber [ 7 ] program during World War II. [ 8 ] [ 1 ] [ 9 ]
Rafferty was born in Chicago, Illinois on May 4, 1886, and studied engineering and chemistry at the Illinois Institute of Technology (where Rafferty would later become a Trustee [ 10 ] [ 9 ] ). After graduation in 1908, Rafferty worked for the People's Gas, Light, and Coke Company and then in 1917 joined the Linde Air Products Company , which later merged with three other companies to become Union Carbide . [ 1 ] [ 9 ]
Rafferty became general manager of the newly formed Union Carbide subsidiary, the Carbide and Carbon Chemicals Corporation ( CCCC ) in 1920. He became vice president in 1924, President in 1929, and chairman of the board in 1944. He was made president of the Bakelite Corporation in 1939 and Chairman of Bakelite in 1944. Under Rafferty's leadership, Carbide and Carbon Chemicals Corporation went on to become the second largest [ 11 ] chemical company in the United States by 1948. [ 3 ] [ 9 ]
Rafferty became a Vice President of Union Carbide, the parent company of the CCCC, in 1938, a Director in 1941, and a member of the executive committee in 1944. [ 1 ] [ 9 ] Rafferty served as Chairman of the Union Carbide's new product development committee until his death on December 19, 1951. [ 3 ]
As a result of lifetime achievements, Rafferty was awarded the Chemical Industry Medal in 1948. [ 12 ] [ 13 ] [ 14 ]
Under the auspices of the Manhattan Project , [ 15 ] Rafferty directed Union Carbide's efforts to enrich uranium (some of which was mined by another Union Carbide subsidiary: the United States Vanadium Corporation ) for use in an atomic bomb . This effort culminated in Union Carbide designing (along with the Kellex Corporation ), building, and operating the massive K-25 gaseous diffusion plant at Oak Ridge . [ 5 ] [ 3 ] [ 9 ] [ 13 ]
General Leslie Groves wrote of Rafferty: [ 8 ] [ 6 ] [ 4 ]
"No one outside the project can ever appreciate how much we depended on you and how well you performed you well-nigh impossible task." [ 8 ]
"Few men were more important in the production of the atomic bomb than he was." [ 6 ]
- General Leslie R. Groves
Stéphane Groueff , in his book chronicling the Manhattan Project, [ 5 ] [ 16 ] [ 17 ] [ 18 ] had this to say about Rafferty:
In every company he dealt with, [Leslie] Groves had a general rule: always try to deal directly with the person who could issue an order that nobody else could countermand. And this did not necessarily mean the president or the chairman of the board. Every company was run in a different way, and often it took some inquiring to find out who was the driving spirit, the executive with the real power of authority in a large corporation.
However, at Union Carbide, even though it was a huge organization with several, nearly autonomous subsidiaries, Groves did not have to search very far. It was common knowledge at Union Carbide that one of the driving forces behind the company's spectacular growth was the executive vice-president, James A. Rafferty.
…
"In recognition of his being 'the workhorse of the Carbide backfield,' " read an article in Chemical and Engineering News, "Rafferty was made vice-president of Union Carbide and Carbon Corporation, the parent corporation of all Carbide units, in 1939. This did little to destroy the idea held by some, however, that over 100 men named James A. Rafferty worked for Union Carbide and its many units." [ 19 ]
An executive with drive and vision, Rafferty contributed tremendously to the birth and fantastic growth of a new industry in America: synthetics made from petroleum rather than from coal, as they had been formerly. In his field, Rafferty was hailed as one of the great "makers of the chemical industry." To him the word synthetic denoted something worthy: a material of uniform quality, designed for a particular purpose; a man-made product far superior to a natural material.
When Leslie Groves was ushered into Rafferty's oak-paneled office, the two men liked each other at sight. Groves realized immediately that he was talking to someone who loved action and efficiency, a man who would push things ahead. As for Rafferty, he was a firm believer in the American system of free enterprise and the importance of industry's participation in the war effort. It was not difficult for the general to convince Rafferty that his corporation should help the Manhattan Project. "The American chemical industry thus far has benefited tremendously from the stimulating atmosphere of American free enterprise," Rafferty used to say. "During several visits to Europe, I studied industries abroad and compared them with our own. I feel that the well-being and national security of a nation is in proportion to the success and extent of its industries." [ 11 ] Rafferty was impressed by Groves's earnest persuasion; he promised to discuss the matter with the top people of those Carbide units that would be involved. [ 5 ]
- Groueff, Stéphane. Manhattan Project: The Untold Story of the Making of the Atomic Bomb. [1st ed.] Boston, Little, Brown, 1967.
On June 1, 1945, prominent industrialists, including Rafferty, were invited to the second meeting of the Interim Committee . [ 20 ] The industrialists were introduced to the committee as follows: [ 21 ]
Mr. George H. Bucher, President of Westinghouse - manufacture of equipment for the electromagnetic process.
Mr. Walter S. Carpenter, President of Du Pont Company - construction of the Hanford Project.
Mr. James Rafferty, Vice President of Union Carbide - construction and operation of gas diffusion plant in Clinton.
Mr. James White, President of Tennessee Eastman - production of basic chemicals and construction of the RDX plant at Holston, Tennessee.
Tennessee Eastman also managed and operated the Y-12 facility at Oak Ridge. In 1947 Union Carbide took over the operation of Y-12.
The graphite for the Hanford B Reactor as well as the Oak Ridge X-10 Reactor was produced by another Union Carbide subsidiary National Carbon Company . [ 22 ]
After Pearl Harbor, the United States was effectively cut off from its supply of natural rubber and a large scale synthetic rubber production process needed to be invented and commercialized. Rafferty led Union Carbide's efforts in producing butadiene which would then be polymerized in a synthetic rubber production process.
The Baruch Committee in 1941 had reported to President Roosevelt : "Of all critical and strategic materials, rubber is the one which presents the greatest threat to the safety of our nation and the success of the Allied cause. If we fail to secure a large new rubber supply quickly, our war effort and domestic economy will collapse."
William M. Jeffers , leader of Union Pacific Railroad and first Rubber Director [ 23 ] for the War Production Board , had this to say of Rafferty:
As my final contribution to the rubber program, I want to say to you with all sincerity that had it not been for you and your great organization, the people who look upon rubber as tires would have been forced to the conclusion that the rubber program was more or less of a failure and so I feel it is fair to say and it is accurate to say that had it not been for the contribution of Carbide and Carbon Chemicals Corporation, this program could not have succeeded. [ 4 ] -William M. Jeffers
Bradley Dewey , co-founder of the Dewey & Almy Chemical Company and the second Rubber Director [ 24 ] for the War Production Board , said of Rafferty:
Before winding up my affairs with the synthetic rubber program, I wish to express my appreciation for the magnificent performance of your organization in the production of raw materials for the GR-S [general-purpose synthetic rubbers formed by copolymerization of emulsions of styrene and butadiene; used in tires and other rubber products; previously also known as Buna-S , currently known as SBR ( styrene-butadiene rubber )]. [ 25 ] [ 26 ] The Carbide and Carbon Chemicals Corporation should be extremely proud of the part it has played in the success of the synthetic rubber program. Without you this country might well have met with disaster. [ 7 ] [ 8 ] [ 4 ] - Bradley Dewey | https://en.wikipedia.org/wiki/James_A._Rafferty |
James Bell (1825–1908) [ 1 ] was a Northern Irish chemist, known for his work on analyses of food, tobacco and alcoholic drinks.
Born at Altnanaghan, Newtownhamilton , County Armagh , he was educated privately and at University College London , where he studied chemistry under Alexander William Williamson . In 1846, he became an assistant in the Inland Revenue Laboratory at Somerset House , established to carry out the provisions of the Tobacco Act 1842 ; and was successively deputy principal from 1867 to 1874, and principal from 1874 till his resignation in 1894. [ 1 ] [ 2 ]
The work of the laboratory was extended to alcoholic products; and when the Food and Drugs Act 1872 was amended in 1875, Bell was made chemical referee when disputed analyses of food were brought to court. Bell elaborated methods for analysing chemically foods within the operation of the Act. He was also consulting chemist to the Indian government, 1869 to 1894. [ 2 ]
Bell's work was recognized in 1884 by his election as Fellow of the Royal Society , and he obtained the degree of Ph.D. from the University of Erlangen in 1882 and received the hon. D.Sc. from the Royal University of Ireland (1886). He was made C.B. in 1889. He was a member of the Playfair committee on British and foreign spirits, and served as president of the Institute of Chemistry from 1888 to 1891. [ 2 ]
Bell's researches into grape and malt ferments were published in the Excise Officers' Manual (1865) and in the Journal of the Chemical Society in 1870. Many of his results were written up in The Analysis and Adulteration of Foods (3 pts. 1881–3; German translation, Berlin, 1882–5). He published also Chemistry of Tobacco (1887). [ 2 ]
Bell married in 1858 Ellen (died 1900), daughter of W. Reece of Chester , and left one son, Sir William James Bell, who became a Barrister and Alderman to the London County Council (1903–7). [ 2 ] [ 3 ]
Bell died at Hove on 31 March 1908, and was buried at Ewell . [ 2 ]
This article incorporates text from a publication now in the public domain : Lee, Sidney , ed. (1912). " Bell, James ". Dictionary of National Biography (2nd supplement) . Vol. 1. London: Smith, Elder & Co. | https://en.wikipedia.org/wiki/James_Bell_(chemist) |
The James Craig Watson Medal was established by the bequest of James Craig Watson , an astronomer the University of Michigan between 1863 and 1879, and is awarded every 1-4 years by the U.S. National Academy of Sciences for contributions to astronomy . [ 1 ]
Source: National Academy of Sciences | https://en.wikipedia.org/wiki/James_Craig_Watson_Medal |
James Robert Durrant CBE FRS [ 5 ] FRSC FLSW (born 1965) is a British photochemist . He is a professor of photochemistry at Imperial College London and Sêr Cymru Solar Professor at Swansea University . [ 6 ] [ 7 ] He serves as director of the centre for plastic electronics (CPE). [ 3 ] [ 8 ] [ 9 ]
Durrant was educated at Gresham's School in Norfolk, the University of Cambridge and Imperial College London , where he was awarded a PhD in 1991 for research on photosystem II using spectroscopy supervised by George Porter and Jim Barber . [ 4 ]
Durrant's research focuses on a range of photochemical applications including solar cells , solar fuel production and photocatalysis , nanomaterials and plastic electronics . [ 10 ] [ 11 ] [ 12 ] Durrant has authored over 400 publications, [ 3 ] [ 9 ] [ 8 ] [ 13 ] focusing on the charge carrier kinetics which determine materials and device function.
Durrant teaches physical chemistry at Imperial College London and is involved in the SPECIFIC Innovation and Knowledge Centre (IKC) at Swansea University .
Durrant was appointed Commander of the Order of the British Empire (CBE) in the 2022 Birthday Honours for services to photochemistry and solar energy research. [ 14 ]
“All text published under the heading 'Biography' on Fellow profile pages is available under Creative Commons Attribution 4.0 International License .” -- Royal Society Terms, conditions and policies at the Wayback Machine (archived 2016-11-11)
This article incorporates text available under the CC BY 4.0 license. | https://en.wikipedia.org/wiki/James_Durrant_(chemist) |
James Fisher and Sons plc ( LSE : FSJ ) is a British provider of marine engineering services, listed on the London Stock Exchange . It also remains a major shipowner, based in Barrow-in-Furness since the 1840s.
The company was founded by James Fisher in 1847 in Barrow-in-Furness as a ship-owning business transporting haematite from the Cumbrian hills. [ 2 ] In 1868 it had 70 ships [ 3 ] and by the 1870s it owned the largest coasting fleet in the United Kingdom . [ 2 ] It acquired the Furness Shipbuilding Company in 1870 but only went on to build one ship, Ellie Park . [ 3 ] During the 1880s it slowly moved from operating sailing ships to operating steamers. [ 4 ]
It was first listed on the London Stock Exchange in 1952. [ 5 ] From the 1960s the company was managed by Directors with no family connection. [ 4 ] At that time it established a reputation for moving heavy equipment, including even locomotives , by sea. [ 4 ] By 1965 it had built its first ship suitable for transporting irradiated nuclear fuel . [ 5 ] In the 1960s the company chartered up to a dozen of its ships to the Atlantic Steam Navigation Company to operate the latter's Preston based container services across the Irish Sea . [ 6 ] In 1984 the company acquired short sea and offshore specialists Coe Metcalf Shipping, lifting the fleet to 42 vessels, and in 1996 it acquired P&O Tankships. [ 7 ]
The company's division James Fisher Defence formerly operated the submarine rescue service for the Royal Navy , and provided the submersible Scorpio 45 which saved the lives of seven Russian sailors in their submarine AS-28 in 2005. [ 8 ] In 2005 James Fisher acquired Fendercare Marine Solutions Ltd for £12m [ 9 ] and in 2007 it acquired Buchan Technical Services for £5m [ 10 ] and F T Everard & Sons Ltd, a leading competitor in the UK coastal shipping market, for £35m. [ 11 ] In 2013 James Fisher acquired Divex Ltd for an initial consideration of £20m in cash plus a further maximum additional consideration of £13m linked to future profitability targets. [ 12 ]
The company operates from various locations throughout the world, with its corporate headquarters in Barrow in Furness , Cumbria, and provides the following services: [ 13 ]
The charter tanker fleet is operated by the subsidiary James Fisher Everard. [ 14 ]
The Sir John Fisher Foundation is a charitable trust established in 1980 by Sir John Fisher and his wife Lady Maria Fisher, in order to support good causes in the area surrounding the company's headquarters in Barrow-in-Furness. The foundation's capital fund includes its shareholding in James Fisher and Sons plc. The dividends paid by the company enable its trustees to make grants to charitable causes, throughout the UK, but with special regard to those based in and working for the benefit of people living in and around Barrow-in-Furness and surrounding area. [ 15 ] | https://en.wikipedia.org/wiki/James_Fisher_&_Sons |
James Franklin (born 1953) is an Australian philosopher, mathematician and historian of ideas .
Franklin was born in Sydney . He was educated at St. Joseph's College, Hunters Hill , New South Wales . His undergraduate work was at the University of Sydney (1971–74), where he attended St John's College and he was influenced by philosophers David Stove and David Armstrong . He completed his PhD in 1981 at the University of Warwick , on algebraic groups . [ 1 ] He taught in the School of Mathematics and Statistics at the University of New South Wales from 1982 until his retirement in 2019. [ 2 ]
His research areas include the philosophy of mathematics and the ' formal sciences ', the history of probability , Australian Catholic history, the parallel between ethics and mathematics, restraint, the quantification of rights in applied ethics , and the analysis of extreme risk . Franklin is the literary executor of David Stove.
He is a Fellow of the Royal Society of New South Wales . [ 3 ]
His 2001 book, The Science of Conjecture: Evidence and Probability Before Pascal , covered the development of thinking about uncertain evidence over many centuries up to 1650. Its central theme was ancient and medieval work on the law of evidence, which developed concepts like half-proof , similar to modern proof beyond reasonable doubt , as well as analyses of aleatory contracts like insurance and gambling . [ 4 ] The book was praised by N.N. Taleb . [ 5 ]
His polemical history of Australian philosophy , Corrupting the Youth (2003), praised the Australian realist tradition in philosophy and attacked postmodernist and relativist trends. [ 6 ]
In the philosophy of mathematics, Franklin defends an Aristotelian realist theory, according to which mathematics is about certain real features of the world, namely the quantitative and structural features (such as ratios and symmetry). [ 7 ] The theory is developed in his 2014 book An Aristotelian Realist Philosophy of Mathematics: Mathematics as the Science of Quantity and Structure . [ 8 ] The theory stands in opposition to both Platonism and nominalism , and emphasises applied mathematics and mathematical modelling as the most philosophically central parts of mathematics. He is the founder of the Sydney School in the philosophy of mathematics . [ 9 ] [ 10 ] [ 11 ] Over the years, the School has hosted emerging Australasian researchers and philosophers such as Anne Newstead, Lisa Dive, and Jeremiah Joven Joaquin. Paul Thagard writes that "the current philosophy of mathematics that fits best with what is known about minds and science is James Franklin's Aristotelian realism." [ 12 ]
In the philosophy of probability, he argues for an objective Bayesian view according to which the relation of evidence to conclusion is strictly a matter of logic. [ 13 ] An example is evidence for and against conjectures in pure mathematics. [ 14 ] His book What Science Knows: And How It Knows It develops the philosophy of science from an objective Bayesian viewpoint.
His work on the parallel between ethics and mathematics [ 15 ] [ 16 ] received the 2005 Eureka Prize for Research in Ethics. [ 17 ]
In 1998 he set up and taught for ten years a course on Professional Issues and Ethics in Mathematics at UNSW. [ 18 ]
He conducted the "Restraint Project", a study of the virtue of temperance or self-control in Australia. [ 19 ] In 2008 he set up the Australian Database of Indigenous Violence. [ 20 ]
His book, The Worth of Persons: The Foundation of Ethics , appeared in 2022. [ 21 ]
Franklin has defended Pascal's Wager [ 22 ] and Leibniz 's Best of all possible worlds theory, [ 23 ] and has discussed emergentism as an alternative to materialist atheism and theism. [ 24 ]
He is the editor of the Journal of the Australian Catholic Historical Society . [ 25 ] His books on Australian Catholic history are Catholic Values and Australian Values (2006), The Real Archbishop Mannix (2015, with G.O.Nolan and M. Gilchrist), Catholic Thought and Catholic Action: Scenes from Australian Catholic Life (2023) and Arthur Calwell (with G.O Nolan). He has written also on the Catholic sexual abuse crisis, [ 26 ] Magdalen laundries , [ 27 ] missions to Aboriginal Australians, [ 28 ] and the virtuous life of Catholic rural communities. [ 29 ] | https://en.wikipedia.org/wiki/James_Franklin_(philosopher) |
James Kazimierz Gimzewski is a Scottish physicist of Polish descent who pioneered research on electrical contacts with single atoms and molecules and light emission using scanning tunneling microscopy (STM). [ 3 ]
Gimzewski was born in Glasgow to Polish World War II war veteran Edmund Gimzewski. He earned his undergraduate degree in 1974 and PhD in 1977 from the University of Strathclyde in Glasgow. Until February 2001, he was a group leader at the IBM Zurich Research Laboratory , where he was involved in nanoscale science since 1983. Currently, he is a Professor in the Department of Chemistry and Biochemistry at UCLA , where he conducts research and advises graduate students in his PicoLab. He is also the faculty director of the Nano & Pico Characterization core lab at the California NanoSystems Institute at UCLA. [ 1 ] [ 2 ]
He pioneered research on electrical contact with single atoms and molecules, light emission and molecular imaging using STM. His accomplishments include the first STM-manipulation of molecules at room temperature , the realization of molecular abacus using buckyballs (C 60 ) , the discovery of single molecule rotors and the development of nanomechanical sensors based on nanotechnology, which explore the ultimate limits of sensitivity and measurement.
Recently [ when? ] , he discovered a new method to synthesize carbon nanotubes more regular in diameter and length. His current interests within CNSI are in the Nanoarchitectonics of molecular systems and molecular and biomolecular machines, in particular those with quantum mechanical possibilities for information processing .
Recently [ when? ] , he has undertaken research in biophysics , which he calls sonocytology . With UCLA graduate student Andrew Pelling, Gimzewski published sonocytology's debut report in the August 2004 issue of Science magazine . In the sonocytology studies, a Bioscope AFM ( atomic force microscope ) was modified to be able to detect the vibrations of the cell wall of a living cell. These vibrations, once amplified using computer software, created audible sound, and it was discovered that cancerous cells emit a slightly different sound than healthy cells do. Gimzewski and Pelling hope that sonocytology may someday have applications in early cancer detection and diagnosis.
In 2001 Gimzewski became Fellow of the Royal Academy of Engineering , [ 4 ] and in 2009 was elected Fellow of the Royal Society , [ 5 ] the highest award in Britain for excellence in Science. He received the 1997 Feynman Prize in Nanotechnology , [ 6 ] the 1997 The Discover Award for Emerging Fields, the 1998 “Wired 25” Award from Wired magazine and the Institute of Physics 2001 Duddell Medal and Prize for his work in nanoscale science. He holds two IBM “Outstanding Innovation Awards”, and is a Fellow of the Institute of Physics and a Chartered Physicist . Gimzewski is a member of scientific boards of Carbon Nanotechnologies, Inc. and Veeco Instruments. [ 1 ] [ 2 ] | https://en.wikipedia.org/wiki/James_Gimzewski |
James Hasting (11 July 1936 – 5 April 2022) was a veteran of the U.S. Air Force , recognized for his expert knowledge in the field of scratch-built model ship construction. [ 1 ] [ 2 ]
As a child, James Hastings lived in New Jersey , where he built model trains , race cars , planes , and ships for a hobby. There wasn’t one particular ‘road to Damascus moment’ that got Hastings into model ship-making. But he ‘drifted into it’ because he came from a family of ship engineers . [ 1 ] [ 3 ]
At 13, Hastings got A Marine Model Company, his first model ship kit . He built many more kits after that first one. [ 1 ] When he finished a BA in economics from Columbia University, Hastings enlisted as an officer in the U.S. Air Force and stayed for a twenty-year career. The military career made model ship making difficult, so he stopped model making for many years. [ 1 ] [ 2 ]
When Hastings was finally able to stay put when stationed at Whiteman AFB , Missouri , the timing was right to get back to model-making. At this time, he began to dedicate much more time to model making, building many kits, and buying books to increase his knowledge. [ 1 ]
In 1972, Hastings decided to start scratch building while stationed in North Dakota . He credits Harold Underhill’s book "Plank-on-Frame Models" (1958) for introducing him to the subject. Another book he cites as critical in his development is “The Anatomy of Nelson’s Ships” (1981) by Nepean Longridge. [ 1 ]
Some models created by Hastings include the Mandalay , which he became familiar with during a cruise aboard the vessel in 2003. He later presented the model to the captain and crew in 2004. His first cutaway model was a replica of the USS Essex . Additionally, Hastings constructed a model of the Susan Constant , (which transported the first colonists from England to Jamestown in 1607). [ 4 ]
Other replicas constructed by Hastings include the HMS Victory , the Parma , the Joseph Conrad , the HMS Endeavour , the HMS Diana , the HMS Blandford , and the HMS Bellona . [ 4 ]
Jim was married to Kathleen for 55 years. He was survived by his two sons, Bill and Rich, his daughter Beth, and his brother, John Hastings. [ 2 ]
In 2019, the Joe Martin Foundation recognized James Hastings by awarding him the title of Craftsman of the Year. [ 5 ]
James Hastings Photos | https://en.wikipedia.org/wiki/James_Hastings_(model_ship_maker) |
Sir James Hopwood Jeans OM FRS [ 1 ] (11 September 1877 – 16 September 1946 [ 2 ] ) was an English physicist , mathematician and an astronomer . He served as a secretary of the Royal Society from 1919 to 1929, and was the president of the Royal Astronomical Society from 1925 to 1927, and won its Gold Medal . [ 3 ]
Born in Ormskirk , Lancashire , the son of William Tulloch Jeans , a parliamentary correspondent and author. Jeans was educated at Merchant Taylors' School , Wilson's Grammar School , [ 4 ] [ 5 ] Camberwell and Trinity College, Cambridge . [ 6 ] As a gifted student, Jeans was counselled to take an aggressive approach to the Cambridge Mathematical Tripos competition: [ 7 ]
Early in the Michaelmas term of 1896, Walker sent for Jeans and Hardy and advised them to take Part I of the Mathematical Tripos in two years. He told them that he could not guarantee that they would come out higher than fifteenth in the list of wranglers , but he understood that they would never regret it. They accepted his advice, and went to R. R. Webb , the most famous private coach of the period ... At the end of his first year, [Jeans] told Walker that he had quarrelled with Webb, his coach. Walker accordingly took Jeans himself, and the result was a triumph: ... Jeans was bracketed second wrangler with J. F. Cameron ... [and] R.W.H.T. Hudson was Senior Wrangler and G. H. Hardy fourth wrangler.
Jeans was elected Fellow of Trinity College in October 1901, [ 8 ] [ 9 ] and taught at Cambridge, but went to Princeton University in 1904 as a professor of applied mathematics. He returned to Cambridge in 1910.
From 1923 to 1944 he was associated with Caltech's Mount Wilson Observatory. [ 10 ]
He made important contributions in many areas of physics, including quantum theory , the theory of radiation and stellar evolution . His analysis of rotating bodies led him to conclude that Pierre-Simon Laplace 's theory that the Solar System formed from a single cloud of gas was incorrect, proposing instead that the planets condensed from material drawn out of the Sun by a hypothetical catastrophic near-collision with a passing star. This theory is not accepted today.
Jeans, along with Arthur Eddington , is a founder of British cosmology . In 1928, Jeans was the first to conjecture a steady state cosmology based on a hypothesized continuous creation of matter in the universe. [ 11 ] In his book Astronomy and Cosmogony (1928) he stated: "The type of conjecture which presents itself, somewhat insistently, is that the centers of the nebulae are of the nature 'singular points' at which matter is poured into our universe from some other, and entirely extraneous spatial dimension, so that, to a denizen of our universe, they appear as points at which matter is being continually created." [ 12 ] This theory fell out of favour when the 1965 discovery of the cosmic microwave background was widely interpreted as the tell-tale signature of the Big Bang .
His scientific reputation is grounded in the monographs The Dynamical Theory of Gases (1904), Theoretical Mechanics (1906), and Mathematical Theory of Electricity and Magnetism (1908). After retiring in 1929, he wrote a number of books for the lay public, including The Stars in Their Courses (1931), The Universe Around Us , Through Space and Time (1934), The New Background of Science (1933), and The Mysterious Universe . These books made Jeans fairly well known as an expositor of the revolutionary scientific discoveries of his day, especially in relativity and physical cosmology .
In 1939, the Journal of the British Astronomical Association reported that Jeans was going to stand as a candidate for parliament for the Cambridge University constituency . The election, expected to take place in 1939 or 1940, did not take place until 1945, and without his involvement.
He also wrote the book Physics and Philosophy (1943) where he explores the different views on reality from two different perspectives: science and philosophy. On his religious views, Jeans was an agnostic Freemason . [ 13 ] [ 14 ]
Jeans married twice, first to the American poet Charlotte Tiffany Mitchell in 1907, who died, [ 15 ] and then to the Austrian organist and harpsichordist Suzanne Hock (better known as Susi Jeans ) in 1935. Susi and Jeans had three children: George, Christopher, and Catherine. [ 16 ] As a birthday present for his wife, he wrote the book Science and Music .
Jeans died in 1947 with the presence of his wife and Joy Adamson , who suggested to the widow to create a death mask of Jeans. It is now held by the Royal Society . [ 17 ] [ 18 ]
One of Jeans' major discoveries, named Jeans length , is a critical radius of an interstellar cloud in space. It depends on the temperature, and density of the cloud, and the mass of the particles composing the cloud. A cloud that is smaller than its Jeans length will not have sufficient gravity to overcome the repulsive gas pressure forces and condense to form a star, whereas a cloud that is larger than its Jeans length will collapse.
Jeans came up with another version of this equation, called Jeans mass or Jeans instability , that solves for the critical mass a cloud must attain before being able to collapse.
Jeans also helped to discover the Rayleigh–Jeans law , which relates the energy density of black-body radiation to the temperature of the emission source.
Jeans is also credited with calculating the rate of atmospheric escape from a planet due to kinetic energy of the gas molecules, a process known as Jeans escape .
Jeans espoused a philosophy of science rooted in the metaphysical doctrine of idealism and opposed to materialism in his speaking engagements and books. His popular science publications first advanced these ideas in 1929's The Universe Around Us when he likened "discussing the creation of the universe in terms of time and space," to, "trying to discover the artist and the action of painting, by going to the edge of the canvas." But he turned to this idea as the primary subject of his best-selling [ 19 ] 1930 book, The Mysterious Universe , where he asserted that a picture of the universe as a "non-mechanical reality" was emerging from the science of the day.
The Universe begins to look more like a great thought than like a great machine. Mind no longer appears to be an accidental intruder into the realm of matter... we ought rather hail it as the creator and governor of the realm of matter.
In a 1931 interview published in The Observer , Jeans was asked if he believed that life was an accident or if it was, "part of some great scheme." He said that he favored, "the idealistic theory that consciousness is fundamental, and that the material universe is derivative from consciousness," going on to suggest that, "each individual consciousness ought to be compared to a brain-cell in a universal mind ." [ 21 ]
In his 1934 address to the British Association for the Advancement of Science meeting in Aberdeen as the Association's president, Jeans spoke specifically to the work of Descartes and its relevance to the modern philosophy of science. He argued that, "There is no longer room for the kind of dualism which has haunted philosophy since the days of Descartes." [ 22 ]
When Daniel Helsing reviewed The Mysterious Universe for Physics Today in 2020, he summarized the philosophical conclusions of the book, "Jeans argues that we must give up science's long-cherished materialistic and mechanical worldview, which posits that nature operates like a machine and consists solely of material particles interacting with each other." His evaluation of Jeans contrasted these philosophical views with modern science communicators such as Neil deGrasse Tyson and Sean Carroll who he suggested, "would likely take issue with Jeans's idealism." [ 19 ]
The Astronomical Horizon https://www.amazon.co.uk/dp/B000NIS57O?ref=myi_title_dp- The Philip Maurice Deneke Lecture 1944 - Published Oxford University Press 1945 | https://en.wikipedia.org/wiki/James_Jeans |
James Kitchenman Coyne III (born November 17, 1946) is an American businessman and former politician. From 1981 to 1983, he served one term as a Republican member of the U.S. House of Representatives from Pennsylvania .
Coyne was born in Farmville, Virginia , and raised in Abington, Pennsylvania, the son of James Kitchenman Coyne Jr. and Pearl Beatrice Black. He graduated from Yale University in 1968 and received an M.B.A. from Harvard Business School in 1970. He was a lecturer at the Wharton School at the University of Pennsylvania from 1974 to 1979 and was president of the George S. Coyne Chemical Corp., Inc., from 1971 to 1981. Coyne was the supervisor of Upper Makefield Township in 1980.
He was elected in 1980 as a Republican to the 97th Congress . He was an unsuccessful candidate for reelection in 1982 .
After his term in Congress, he served from 1983 to 1985 as a special assistant to President Ronald Reagan and as director of the White House Office of Private Sector Initiatives, in 1985–1986 as chief executive officer of the American Consulting Engineers Council, and as president of the American Tort Reform Association from 1986 to 1988. In 1987, he founded Americans to Limit Congressional Terms.
Coyne co-authored (with John Fund ) "Cleaning House," which promoted state referendums to limit the terms of Members of Congress. In 1994 he was chosen president of the National Air Transportation Association, where he served until 2012.
He married Helen Biddle Mercer on October 24, 1970. They have three children, Alexander Black Coyne (born 1977), Katherine Mercer Coyne (born 1980) and Michael Atkinson Coyne (born 1982). He is a great-great-grandson of Philadelphia manufacturer James Kitchenman . | https://en.wikipedia.org/wiki/James_K._Coyne_III |
James Cullen Kirkcaldie (18 April 1875 – 16 August 1931) was a New Zealand cricketer . He played in one first-class match for Wellington in 1903/04. [ 1 ] [ 2 ]
Kirkcaldie was an analytical chemist . [ 3 ]
This biographical article related to a New Zealand cricket person born in the 1870s is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/James_Kirkcaldie |
Ceremonial magic (also known as magick , ritual magic , high magic or learned magic ) [ 1 ] encompasses a wide variety of rituals of magic . The works included are characterized by ceremony and numerous requisite accessories to aid the practitioner. It can be seen as an extension of ritual magic, and in most cases synonymous with it. Popularized by the Hermetic Order of the Golden Dawn , it draws on such schools of philosophical and occult thought as Hermetic Qabalah , Enochian magic , Thelema , and the magic of various grimoires . Ceremonial magic is part of Hermeticism and Western esotericism .
The synonym magick is an archaic spelling of 'magic' [ 2 ] used during the Renaissance , which was revived by Aleister Crowley to differentiate occult magic from stage magic . He defined it as "the Science and Art of causing Change to occur in conformity with Will", [ 3 ] including ordinary acts of will as well as ritual magic. Crowley wrote that "it is theoretically possible to cause in any object any change of which that object is capable by nature". [ a ] John Symonds and Kenneth Grant attach a deeper occult significance to this preference. [ b ]
Crowley saw magic as the essential method for a person to reach true understanding of the self and to act according to one's true will , which he saw as the reconciliation "between freewill and destiny." [ 4 ] Crowley describes this process in his Magick, Book 4 . [ c ]
The term magick is an Early Modern English spelling for magic , used in works such as the 1651 translation of Heinrich Cornelius Agrippa 's De Occulta Philosophia , Three Books of Occult Philosophy, or Of Magick . Aleister Crowley chose the spelling to differentiate his practices and rituals from stage magic (which may be more appropriately termed "illusion") and the term has since been re-popularised by those who have adopted elements of his teachings. Crowley defined Magick as "the science and art of causing change to occur in conformity with will." [ 5 ] [ 6 ]
The Tree of Life is a tool used to categorize and organize various mystical concepts. At its most simple level, it is composed of ten spheres, or emanations, called sephiroth (sing. "sephira") which are connected by twenty two paths. The sephiroth are represented by the planets and the paths by the characters of the Hebrew alphabet , which are subdivided by the four classical elements , the seven classical planets, and the twelve signs of the Zodiac . Within the western magical tradition, the Tree is used as a kind of conceptual filing cabinet. Each sephira and path is assigned various ideas, such as gods, cards of the Tarot, astrological planets and signs, elements, etc.
Crowley considered a deep understanding of the Tree of Life to be essential to the magician:
The Tree of Life has got to be learnt by heart; you must know it backwards, forwards, sideways, and upside down; it must become the automatic background of all your thinking. You must keep on hanging everything that comes your way upon its proper bough. [ 7 ]
Similar to yoga, learning the Tree of Life is not so much magic as it is a way to map out one's spiritual universe. As such, the adept may use the Tree to determine a destination for astral travel, to choose which gods to invoke for what purposes, et cetera. It also plays an important role in modeling the spiritual journey, where the adept begins in Malkuth , which is the every-day material world of phenomena, with the ultimate goal being at Kether , the sphere of Unity with the All.
The body of light, sometimes called the 'astral body' [ d ] or the 'subtle body,' [ e ] is a "quasi material" [ 8 ] aspect of the human body, being neither solely physical nor solely spiritual, posited by a number of philosophers, and elaborated on according to various esoteric , occult , and mystical teachings. Other terms used for this body include body of glory, [ 9 ] spirit-body, radiant body, [ 10 ] luciform body, augoeides ('radiant'), astroeides ('starry' or 'sidereal body'), and celestial body. [ 11 ]
Crowley referred to the augoeides , a Greek term for the body of light, and connected it with 'the Knowledge & Conversation of the Holy Guardian Angel ' associated with each human being. [ 12 ] [ 13 ] He stressed that the body of light must be built up though the use of imagination, and that it must then be animated, exercised, and disciplined. [ 14 ] According to Asprem (2017):
The practice of creating a "body of light” in imagination builds on the body-image system, potentially working with alterations across all of its three modalities (perceptual, conceptual, and affective): an idealized body is produced (body-image model), new conceptual structures are attached to it (e.g., the doctrine of multiple, separable bodies), while emotional attachments of awe, dignity, and fear responses are cultivated through the performance of astral rituals and protections from "astral dangers" through the simulation of symbols and magical weapons. [ 14 ]
A grimoire is a textbook of magic , typically including instructions on how to create magical objects like talismans and amulets , how to perform magical spells , charms and divination , and how to summon or invoke supernatural entities such as angels , spirits , deities , and demons . [ 15 ] In many cases, the books themselves are believed to be imbued with magical powers, although in many cultures, other sacred texts that are not grimoires (such as the Bible ) have been believed to have supernatural properties intrinsically. The only contents found in a grimoire would be information on spells, rituals, the preparation of magical tools, and lists of ingredients and their magical correspondences . In this manner, while all books on magic could be thought of as grimoires, not all magical books should be thought of as grimoires. [ 16 ]
While the term grimoire is originally European—and many Europeans throughout history, particularly ceremonial magicians and cunning folk , have used grimoires—the historian Owen Davies noted that similar books can be found all around the world, ranging from Jamaica to Sumatra . [ 17 ] He also noted that in this sense, the world's first grimoires were created in Europe and the Ancient Near East . [ 18 ]
A magical formula or 'word of power' is a word that is believed to have specific supernatural effects. [ 19 ] They are words whose meaning illustrates principles and degrees of understanding that are often difficult to relay using other forms of speech or writing. It is a concise means to communicate very abstract information through the medium of a word or phrase.
These words often have no intrinsic meaning in and of themselves. However, when deconstructed, each individual letter may refer to some universal concept found in the system in which the formula appears. Additionally, in grouping certain letters together one is able to display meaningful sequences that are considered to be of value to the spiritual system that utilizes them (e.g., spiritual hierarchies, historiographic data, psychological stages, etc.)
A formula's potency is understood and made usable by the magician only through prolonged meditation on its levels of meaning. Once these have been interiorized by the magician, they may then utilize the formula to maximum effect.
A magical record is a journal or other source of documentation containing magical events, experiences, ideas, and any other information that the magician may see fit to add. There can be many purposes for such a record, such as recording evidence to verify the effectiveness of specific procedures (per the scientific method that Aleister Crowley claimed should be applied to the practice of magic) or to ensure that data may propagate beyond the lifetime of the magician. Benefits of this process vary, but usually include future analysis and further education by the individual and/or associates with whom the magician feels comfortable in revealing such intrinsically private information.
Crowley was highly insistent upon the importance of this practice. As he writes in Liber E, "It is absolutely necessary that all experiments should be recorded in detail during, or immediately after, their performance ... The more scientific the record is, the better. Yet the emotions should be noted, as being some of the conditions. Let then the record be written with sincerity and care; thus with practice it will be found more and more to approximate to the ideal." [ 20 ] Other items he suggests for inclusion include the physical and mental condition of the experimenter, the time and place, and environmental conditions, including the weather.
The practice of ceremonial magic often requires tools made or consecrated specifically for this use, called magical weapons, which are required for a particular ritual or series of rituals. They may be a symbolic representation of psychological elements of the magician or of metaphysical concepts.
In Magick (Book 4) , Part II (Magick) , Aleister Crowley lists the tools required as a magic circle drawn on the ground and inscribed with the names of god, an altar, a wand, cup, sword, and pentacle, to represent his true will , his understanding , his reason, and the lower parts of his being respectively. On the altar, too, is a phial of oil to represent his aspiration, and for consecrating items to his intent. The magician is surrounded by a scourge, dagger, and chain intended to keep his intent pure. An oil lamp, book of conjurations and bell are required, as is the wearing of a crown, robe, and lamen . The crown affirms his divinity, the robe symbolizes silence, and the lamen declare his work. The book of conjurations is his magical record, his karma . In the East is the magic fire in which all burns up at last. [ 21 ]
According to Crowley, there is a single definition of the purpose for ritual magic: to achieve Union with God through "the uniting of the Microcosm with the Macrocosm." [ 22 ] Since this process is so arduous, it is also acceptable to use magic to develop the self (i.e. one's body of light ) or to create ideal circumstances for the Work (e.g. having access to a place in which to do ritual undisturbed). There are many kinds of magic, but the categories of ritual that are recommended by Crowley include:
In magical rituals, a vocal technique called vibration is commonly used. [ 23 ] This was a basic aspect of magical training for Crowley, who described it in "Liber O." [ 24 ] According to that text, vibration involves a physical set of steps, starting in a standing position, breathing in through the nose while imagining the name of the god entering with the breath, imagining that breath travelling through the entire body, stepping forward with the left foot while throwing the body forward with arms outstretched, visualizing the name rushing out when spoken, ending in an upright stance, with the right forefinger placed upon the lips. According to Crowley in "Liber O", success in this technique is signaled by physical exhaustion and "though only by the student himself is it perceived, when he hears the name of the God vehemently roared forth, as if by the concourse of ten thousand thunders; and it should appear to him as if that Great Voice proceeded from the Universe, and not from himself." [ 25 ]
The purpose of banishing rituals is to eliminate forces that might interfere with a magical operation, and they are often performed at the beginning of an important event or ceremony (although they can be performed for their own sake as well). The area of effect can be a magic circle or a room. The general theory of magic proposes that there are various forces which are represented by the classical elements (air, earth, fire, and water), the planets, the signs of the Zodiac , and adjacent spaces in the astral world. [ citation needed ] There are many banishing rituals, but most are some variation on two of the most common—"The Star Ruby" and the Lesser Banishing Ritual of the Pentagram .
Crowley describes banishing in his Magick, Book 4 (ch.13):
[...] in the banishing ritual of the pentagram we not only command the demons to depart, but invoke the Archangels and their hosts to act as guardians of the Circle during our pre-occupation with the ceremony proper. In more elaborate ceremonies it is usual to banish everything by name. Each element, each planet, and each sign, perhaps even the Sephiroth themselves; all are removed, including the very one which we wished to invoke, for that forces as existing in Nature is always impure. But this process, being long and wearisome, is not altogether advisable in actual working. It is usually sufficient to perform a general banishing, and to rely upon the aid of the guardians invoked. [...] "The Banishing Ritual of the Pentagram" is the best to use. [ 26 ]
He further states:
Those who regard this ritual as a mere devise to invoke or banish spirits, are unworthy to possess it. Properly understood, it is the Medicine of Metals and the Stone of the Wise. [ 27 ]
Purification is similar in theme to banishing, but is a more rigorous process of preparing the self and her temple for serious spiritual work. Crowley mentions that ancient magicians would purify themselves through arduous programs, such as through special diets, fasting, sexual abstinence, keeping the body meticulously tidy, and undergoing a complicated series of prayers . [ 26 ] He goes on to say that purification no longer requires such activity, since the magician can purify the self via willed intention. Specifically, the magician labors to purify the mind and body of all influences which may interfere with the Great Work:
The point is to seize every occasion of bringing every available force to bear upon the objective of the assault. It does not matter what the force is (by any standard of judgment) so long as it plays its proper part in securing the success of the general purpose [...] We must constantly examine ourselves, and assure ourselves that every action is really subservient to the One Purpose [ 26 ]
Crowley recommended symbolically ritual practices, such as bathing and robing before a main ceremony: "The bath signifies the removal of all things extraneous or antagonistic to the one thought. The putting on of the robe is the positive side of the same operation. It is the assumption of the frame of mind suitable to that one thought." [ 26 ]
Consecration is an equally important magical operation. It is essentially the dedication, usually of a ritual instrument or space, to a specific purpose. In Magick, Book 4 (ch.13), Crowley writes:
The ritual here in question should summarize the situation, and devote the particular arrangement to its purpose by invoking the appropriate forces. Let it be well remembered that each object is bound by the Oaths of its original consecration as such. Thus, if a pantacle has been made sacred to Venus, it cannot be used in an operation of Mars. [ 26 ]
Invocation is the bringing in or identifying with a particular deity or spirit. Crowley wrote of two keys to success in this arena: to "inflame thyself in praying" [ 28 ] and to "invoke often". For Crowley, the single most important invocation, or any act of magic for that matter, was the invocation of one's Holy Guardian Angel , or "secret self", which allows the adept to know his or her true will .
Crowley describes the experience of invocation:
The mind must be exalted until it loses consciousness of self. The Magician must be carried forward blindly by a force which, though in him and of him, is by no means that which he in his normal state of consciousness calls I. Just as the poet, the lover, the artist, is carried out of himself in a creative frenzy, so must it be for the Magician. [ 28 ]
Crowley ( Magick, Book 4 ) discusses three main categories of invocation, although "in the great essentials these three methods are one. In each case the magician identifies himself with the Deity invoked." [ 29 ]
Another invocatory technique that the magician can employ is called the assumption of godforms — where with "concentrated imagination of oneself in the symbolic shape of any God, one should be able to identify oneself with the idea which [the god] represents." [ 30 ] A general method involves positioning the body in a position that is typical for a given god, imagining that the image of the god is coinciding with or enveloping the body, accompanied by the practice of "vibration" of the appropriate god-name(s).
There is a distinct difference between invocation and evocation, as Crowley explains:
To "invoke" is to "call in", just as to "evoke" is to "call forth". This is the essential difference between the two branches of Magick. In invocation, the macrocosm floods the consciousness. In evocation, the magician, having become the macrocosm, creates a microcosm. You in voke a God into the Circle. You e voke a Spirit into the Triangle. [ 29 ]
Generally, evocation is used for two main purposes: to gather information and to obtain the services or obedience of a spirit or demon. Crowley believed that the most effective form of evocation was found in the grimoire on Goetia (see below), which instructs the magician in how to safely summon forth and command 72 infernal spirits. However, it is equally possible to evoke angelic beings, gods, and other intelligences related to planets, elements, and the Zodiac.
Unlike with invocation, which involves a calling in, evocation involves a calling forth, most commonly into what is called the "triangle of art."
The word eucharist originally comes from the Greek word for thanksgiving. However, within magic, it takes on a special meaning—the transmutation of ordinary things (usually food and drink) into divine sacraments, which are then consumed. The object is to infuse the food and drink with certain properties, usually embodied by various deities, so that the adept takes in those properties upon consumption. Crowley describes the process of the regular practice of eucharistic ritual:
The magician becomes filled with God, fed upon God, intoxicated with God. Little by little his body will become purified by the internal lustration of God; day by day his mortal frame, shedding its earthly elements, will become in very truth the Temple of the Holy Ghost. Day by day matter is replaced by Spirit, the human by the divine; ultimately the change will be complete; God manifest in flesh will be his name. [ 31 ]
There are several eucharistic rituals within the magical canon. Two of the most well known are the Mass of the Phoenix and the Gnostic Mass . The first is a ritual designed for the individual, which involves sacrificing a " Cake of Light " (a type of bread that serves as the host) to Ra (i.e. the Sun) and infusing a second Cake with the adept's own blood (either real or symbolic, in a gesture reflecting the myth of the Pelican cutting its own breast to feed its young) and then consuming it with the words, "There is no grace: there is no guilt: This is the Law: Do what thou wilt!" The other ritual, The Gnostic Mass, is a very popular public ritual (although it can be practiced privately) that involves a team of participants, including a Priest and Priestess. This ritual is an enactment of the mystical journey that culminates with the Mystic Marriage and the consumption of a Cake of Light and a goblet of wine (a process termed "communication"). Afterwards, each Communicant declares, "There is no part of me that is not of the gods!"
The art of divination is generally employed for the purpose of obtaining information that can guide the adept in his Great Work . The underlying theory states that there exists intelligences (either outside of or inside the mind of the diviner) that can offer accurate information within certain limits using a language of symbols. Normally, divination within magic is not the same as fortune telling , which is more interested in predicting future events. Rather, divination tends to be more about discovering information about the nature and condition of things that can help the magician gain insight and to make better decisions.
There are literally hundreds of different divinatory techniques in the world. However, Western occult practice mostly includes the use of astrology (calculating the influence of heavenly bodies), bibliomancy (reading random passages from a book, such as Liber Legis or the I Ching ), Thoth Tarot (a deck of 78 cards, each with symbolic meaning, usually laid out in a meaningful pattern), and geomancy (a method of making random marks on paper or in earth that results in a combination of sixteen patterns).
It is an accepted truism within magic that divination is imperfect. As Crowley writes, "In estimating the ultimate value of a divinatory judgment, one must allow for more than the numerous sources of error inherent in the process itself. The judgment can do no more than the facts presented to it warrant. It is naturally impossible in most cases to make sure that some important factor has not been omitted [...] One must not assume that the oracle is omniscient." [ 32 ]
The term originates in 16th-century Renaissance magic , referring to practices described in various Medieval and Renaissance grimoires and in collections such as that of Johannes Hartlieb . Georg Pictor uses the term synonymously with goetia .
James Sanford in his 1569 translation of Heinrich Cornelius Agrippa 's 1526 De incertitudine et vanitate scientiarum has "The partes of ceremoniall Magicke be Geocie, and Theurgie". For Agrippa, ceremonial magic was in opposition to natural magic . While he had his misgivings about natural magic, which included astrology , alchemy , and also what we would today consider fields of natural science , such as botany , he was nevertheless prepared to accept it as "the highest peak of natural philosophy". Ceremonial magic, on the other hand, which included all sorts of communication with spirits, including necromancy and witchcraft , he denounced in its entirety as impious disobedience towards God. [ 33 ]
Among the various sources for ceremonial magic, Francis Barrett , a late 18th-century Englishman, called himself a student of chemistry , metaphysics , and natural occult philosophy . [ 34 ] Barrett was enthusiastic about reviving interest in the occult arts, and published a magical textbook called The Magus . The Magus dealt with the natural magic of herbs and stones , magnetism , talismanic magic , alchemy , numerology , the elements , and biographies of famous adepts from history. It was a compilation, [ 35 ] almost entirely consisting of selections from Cornelius Agrippa 's Three Books of Occult Philosophy , the Fourth Book of Occult Philosophy attributed to Agrippa, and Robert Turner 's 1655 translation of the Heptameron of Peter of Abano . Barrett made modifications and modernized spelling and syntax. Possibly influencing the novelist Edward Bulwer-Lytton , the book gained little other notice until it influenced Eliphas Levi . [ citation needed ]
Éliphas Lévi (1810–1875) conceived the notion of writing a treatise on magic with his friend Bulwer-Lytton . This appeared in 1855 under the title Dogme et Rituel de la Haute Magie , and was translated into English by Arthur Edward Waite as Transcendental Magic, its Doctrine and Ritual .
In 1861, he published a sequel, La Clef des Grands Mystères ( The Key to the Great Mysteries ). Further magical works by Lévi include Fables et Symboles ( Stories and Images ), 1862, and La Science des Esprits ( The Science of Spirits ), 1865. In 1868, he wrote Le Grand Arcane, ou l'Occultisme Dévoilé ( The Great Secret, or Occultism Unveiled ); this, however, was only published posthumously in 1898.
Lévi's version of magic became a great success, especially after his death. That Spiritualism was popular on both sides of the Atlantic from the 1850s contributed to his success. His magical teachings were free from obvious fanaticisms, even if they remained rather murky; he had nothing to sell, and did not pretend to be the initiate of some ancient or fictitious secret society . He incorporated the Tarot cards into his magical system, and as a result the Tarot has been an important part of the paraphernalia of Western magicians . He had a deep impact on the magic of the Hermetic Order of the Golden Dawn and later Aleister Crowley, and it was largely through this impact that Lévi is remembered as one of the key founders of the twentieth century revival of magic.
The Hermetic Order of the Golden Dawn (founded 1888) was a secret society devoted to the study and practice of the occult , metaphysics , and paranormal activities during the late 19th and early 20th centuries. Known as a magical order , the Hermetic Order of the Golden Dawn was active in Great Britain and focused its practices on theurgy and spiritual development. Many present-day concepts of ritual and magic that are at the centre of contemporary traditions, such as Wicca [ 36 ] and Thelema , were inspired by the Golden Dawn, which became one of the largest single influences on 20th century Western occultism . [ f ] [ g ]
The three founders, William Robert Woodman , William Wynn Westcott , and Samuel Liddell Mathers , were Freemasons . Westcott appears to have been the initial driving force behind the establishment of the Golden Dawn. [ citation needed ]
The "Golden Dawn" was the first of three Orders, although all three are often collectively referred to as the "Golden Dawn". The First Order taught esoteric philosophy based on the Hermetic Qabalah and personal development through study and awareness of the four classical elements , as well as the basics of astrology , tarot divination , and geomancy . The Second or Inner Order, the Rosae Rubeae et Aureae Crucis , taught magic, including scrying , astral travel , and alchemy . [ citation needed ]
English author and occultist Aleister Crowley (1875–1947) wrote about magical practices and theory, including those of theurgy ("high magic") and goetia ("low magic"). In The Book of the Law and The Vision and the Voice , the Aramaic magical formula Abracadabra was changed to Abrahadabra , which he called the new formula of the Aeon of Horus . He also famously spelled magic in the archaic manner, as 'magick', to differentiate "the true science of the Magi from all its counterfeits." [ 37 ] He also stated that "The spirits of the Goetia are portions of the human brain." [ 38 ]
His book Magick, Liber ABA, Book 4 , is a lengthy treatise on magic in which he which also presents his own system of Western occult practice, synthesised from many sources, including Yoga , Hermeticism , medieval grimoires , contemporary magical theories from writers like Eliphas Levi and Helena Blavatsky , and his own original contributions. It consists of four parts: Mysticism, Magick (Elementary Theory), Magick in Theory and Practice, and ΘΕΛΗΜΑ—the Law (The Equinox of The Gods). It also includes numerous appendices presenting many rituals and explicatory papers. [ citation needed ]
Dion Fortune (1890–1946) was a Welsh occultist , ceremonial magician, novelist and author. She was a co-founder of the Fraternity of the Inner Light , an occult organisation that promoted philosophies which she claimed had been taught to her by spiritual entities known as the Ascended Masters . A prolific writer, she produced a large number of articles and books on her occult ideas and also authored seven novels, several of which expound occult themes.
Fortune was a ceremonial magician. [ 39 ] The magical principles on which her Fraternity was based were adopted from the late nineteenth century Hermetic Order of the Golden Dawn, with other influences coming from Theosophy and Christian Science. [ 40 ] The magical ceremonies performed by Fortune's Fraternity were placed into two categories: initiations, in which the candidate was introduced to magical forces, and evocation, in which these forces were manipulated for a given purpose. [ 41 ]
The Fraternity's rituals at their Bayswater temple were carried out under a dim light, as Fortune believed that bright light disperses etheric forces. [ 41 ] An altar was placed in the centre of a room, with the colours of the altar-cloth and the symbols on the altar varying according to the ceremony being performed. A light was placed on the altar while incense, usually frankincense , was burned. [ 41 ] The senior officers sat in a row along the eastern end of the room, while officers—who were believed to be channels for cosmic forces—were positioned at various positions on the floor. The lodge was opened by walking around the room in a circle chanting, with the intent of building a psychic force up as a wall. [ 42 ] Next, the cosmic entities would be invoked, with the members believing that these entities would manifest in astral form and interact with the chosen officers. [ 42 ]
Fortune was particularly concerned with the issue of sex. [ 43 ] She believed that this erotic attraction between men and women could be harnessed for use in magic. [ 44 ] She urged her followers to be naked under their robes when carrying out magical rituals, for this would increase the creative sexual tension between the men and women present. [ 45 ] Although sex features in her novels, it is never described in graphic detail. [ 46 ] The scholar Andrew Radford noted that Fortune's "reactionary and highly heteronormative" view of "sacralised sexuality" should be seen as part of a wider tradition among esoteric currents, going back to the ideas of Emanuel Swedenborg and Andrew Jackson Davis and also being found in the work of occultists like Paschal Beverly Randolph and Ida Craddock . [ 47 ]
The religious studies scholar Hugh Urban noted that Fortune was "one of the key links" between early twentieth-century ceremonial magic and the developing Pagan religion of Wicca . [ 43 ] Similarly, the Wiccan high priestess Vivianne Crowley characterised Fortune as a "proto-Pagan". [ 48 ] The scholar and esotericist Nevill Drury stated that Fortune "in many ways anticipated feminist ideas in contemporary Wicca", particularly through her belief that all goddesses were a manifestation of a single Great Goddess. [ 49 ] Graf agreed, adding that Fortune's works found "resonance" in the work of the later feminist Wiccan Starhawk , and in particular in the latter's 1979 book, The Spiral Dance . [ 50 ]
In researching ceremonial magic orders and other esoteric groups active in the London area during the 1980s, Luhrmann found that within them, Fortune's novels were treated as "fictionalized ideals" and that they were recommended to newcomers as the best way to understand magic. [ 51 ] The Pagan studies scholar Joanne Pearson added that Fortune's books, and in particular the novels The Sea Priestess and Moon Magic , were owned by many Wiccans and other Pagans. [ 48 ] The religious studies scholar Graham Harvey compared The Sea Priestess to the Wiccan Gerald Gardner 's 1949 novel High Magic's Aid , stating that while neither were "great literature", they "evoke Paganism better than later more didactic works". [ 52 ]
John Whiteside Parsons (1914–1952) was an American rocket engineer , chemist , and Thelemite occultist . Parsons converted to Thelema , the new religious movement founded by the English occultist Aleister Crowley. Together with his first wife, Helen Northrup, Parsons joined the Agape Lodge , the Californian branch of Ordo Templi Orientis (O.T.O.) in 1941. At Crowley's bidding, Parsons replaced Wilfred Talbot Smith as its leader in 1942 and ran the Lodge from his mansion on Orange Grove Boulevard.
Parsons identified four obstacles that prevented humans from achieving and performing their true will , all of which he connected with fear: the fear of incompetence, the fear of the opinion of others, the fear of hurting others, and the fear of insecurity. He insisted that these must be overcome, writing that "The Will must be freed of its fetters. The ruthless examination and destruction of taboos, complexes, frustrations, dislikes, fears and disgusts hostile to the Will is essential to progress." [ 53 ]
In 1945, Parsons separated from Helen, after having an affair with her sister Sara ; when Sara left him for L. Ron Hubbard , Parsons conducted the Babalon Working , a series of rituals intended to invoke the Thelemic goddess Babalon on Earth. The Babalon Working was a series of magic ceremonies or rituals performed from January to March 1946 by Parsons and Scientology founder L. Ron Hubbard . [ h ] This ritual was essentially designed to manifest an individual incarnation of the archetypal divine feminine called Babalon . The project was based on the ideas of Crowley, and his description of a similar project in his 1917 novel Moonchild . [ i ]
When Parsons declared that the first of the series of rituals was complete and successful, he almost immediately met Marjorie Cameron in his own home, and regarded her as the elemental that he and Hubbard had called through the ritual. [ 54 ] Soon Parsons began the next stage of the series, an attempt to conceive a child through sex magic workings. Although no child was conceived, this did not affect the result of the ritual to that point. Parsons and Cameron, who Parsons now regarded as the Scarlet Woman, Babalon , called forth by the ritual, soon married. [ citation needed ]
The rituals performed drew largely upon rituals and sex magic described by Crowley. Crowley was in correspondence with Parsons during the course of the Babalon Working, and warned Parsons of his potential overreactions to the magic he was performing, while simultaneously deriding Parsons' work to others. [ 55 ]
A brief text entitled Liber 49 , self-referenced within the text as The Book of Babalon , was written by Jack Parsons as a transmission from the goddess or force called 'Babalon' received by him during the Babalon Working. [ 54 ] Parsons wrote that Liber 49 constituted a fourth chapter of Crowley's Liber AL Vel Legis ( The Book of the Law ) , the holy text of Thelema . [ 56 ]
Phyllis Seckler (1917–2004), also known as 'Soror Meral', was a ninth degree (IX°) member of the Sovereign Sanctuary of the Gnosis of Ordo Templi Orientis (O.T.O.), and a lineage holder in the A∴A∴ tradition. She was a student of Jane Wolfe , herself a student of Aleister Crowley. [ 57 ]
Sekler was a member of O.T.O. Agape Lodge, the only working Lodge of the O.T.O. at the time of Aleister Crowley's death. Seckler was also instrumental in preserving important parts of Crowley's literary heritage, typing parts of his Confessions , and the complete texts of The Vision and the Voice and Magick Without Tears during the 1950s. Seckler was also instrumental in re-activing the O.T.O. with Grady Louis McMurtry , during the early-mid 1970s, following the death of Crowley's appointed successor, Karl Germer .
Seckler continued her lifelong work with the A∴A∴ , founding the College of Thelema and co-founding (with James A. Eshelman) the Temple of Thelema , and later warranting the formation of the Temple of the Silver Star . Seeking to guide her students to an understanding of the Law of Thelema, especially deeper understanding of oneself and of one's magical will, Sekler published the bi-annual Thelemic journal In the Continuum which featured her essays on Thelema and initiation as well as instructional articles for the students of the A.:.A.:., illustrations and essays which help to clarify some of Crowley's thoughts and aid in the understanding of Thelemic principles expressed in Liber AL . Printed for 20 years from 1976 through 1996, In the Continuum also published rare works by Aleister Crowley which at the time were out of print or hard to find. [ 58 ]
Seckler served as a master of 418 Lodge of O.T.O. in California from its inception in 1979 until her death.
Kenneth Grant (1924–2011) was an English ceremonial magician and advocate of the Thelemic religion. A poet, novelist, and writer, he founded his own Thelemic organisation, the Typhonian Ordo Templi Orientis —later renamed the Typhonian Order—with his wife Steffi Grant.
Grant was fascinated by the work of the occultist Aleister Crowley, having read a number of his books. Eager to meet Crowley, Grant wrote letters to Crowley's publishers, asking that they pass his letters on to Crowley himself. [ 59 ] These eventually resulted in the first meeting between the two, in autumn 1944, [ 59 ] at the Bell Inn in Buckinghamshire . [ 60 ] After several further meetings and an exchange of letters, Grant agreed to work for Crowley as his secretary and personal assistant. Now living in relative poverty, Crowley was unable to pay Grant for his services in money, instead paying him in magical instruction. [ 61 ]
In March 1945, Grant moved into a lodge cottage in the grounds of Netherwood, a Sussex boarding house where Crowley was living. [ 62 ] He continued living there with Crowley for several months, dealing with the old man's correspondences and needs. In turn, he was allowed to read from Crowley's extensive library on occult subjects, and performed ceremonial magic workings with him, becoming a high initiate of Crowley's magical group, Ordo Templi Orientis (O.T.O.). [ 63 ] Crowley saw Grant as a potential leader of O.T.O. in the UK, writing in his diary, "value of Grant. If I die or go to the USA, there must be a trained man to take care of the English O.T.O." [ 64 ]
Grant drew eclectically on a range of sources in devising his teachings. [ 65 ] Although based in Thelema, Grant's Typhonian tradition has been described as "a bricolage of occultism, Neo-Vedanta, Hindu tantra, Western sexual magic, Surrealism, ufology and Lovecraftian gnosis". [ 66 ] According to Djurdjevic, Grant's writing style is notorious for being opaque with "verbal and conceptual labyrinths". [ 67 ] The historian of religion, Manon Hedenborg White, noted that "Grant's writings do not lend themselves easily to systematization". [ 68 ] She added that he "deliberately employs cryptic or circuitous modes of argumentation", [ 69 ] and lacks clear boundaries between fact and fiction. [ 65 ]
Grant promoted what he termed the Typhonian or Draconian tradition of magic, [ 70 ] and wrote that Thelema was only a recent manifestation of this wider tradition. [ 71 ] In his books, he portrayed the Typhonian tradition as the world's oldest spiritual tradition, writing that it had ancient roots in Africa. [ 72 ] The religious studies scholar Gordan Djurdjevic noted that Grant's historical claims regarding Typhonian history were "at best highly speculative" and lacked any supporting evidence, however he suggested that Grant may never have intended these claims to be taken literally. [ 73 ]
Grant adopted a perennialist interpretation of the history of religion. [ 74 ] Grant's wrote that Indian spiritual traditions like Tantra and Yoga correlate to Western esoteric traditions, and that both stem from a core, ancient source, has parallels in the perennial philosophy promoted by the Traditionalist School of esotericists. [ 75 ] He believed that by mastering magic, one masters this illusory universe, gaining personal liberation and recognising that only the Self really exists. [ 76 ] Doing so, according to Grant, leads to the discovery of one's true will, the central focus of Thelema. [ 73 ]
Grant further wrote that the realm of the Self was known as "the Mauve Zone", and that it could be reached while in a state of deep sleep, where it has the symbolic appearance of a swamp. [ 77 ] He also believed that the reality of consciousness, which he deemed the only true reality, was formless and thus presented as a void, although he also taught that it was symbolised by the Hindu goddess Kali and the Thelemic goddess Nuit . [ 78 ]
Grant's views on sex magic drew heavily on the importance of sexual dimorphism among humans and the subsequent differentiation of gender roles. [ 79 ] Grant taught that the true secret of sex magic were bodily secretions, the most important of which was a woman's menstrual blood. [ 72 ] In this he differed from Crowley, who viewed semen as the most important genital secretion. [ 80 ] Grant referred to female sexual secretions as kalas , a term adopted from Sanskrit . [ 81 ] He thought that because women have kalas, they have oracular and visionary powers. [ 69 ] The magical uses of female genital secretions are a recurring theme in Grant's writings. [ 82 ]
James Lees (August 22, 1939 [ 83 ] – 2015) was an English magician known for inventing the system he called English Qaballa .
Lees was born in Bolton, Lancashire . He established a career as an analytic chemist . In his search for truth, he also studied psychology. Not finding the answers he wanted from science, he turned to the study of astrology, even making a living for a time as a horary astrologer . [ 83 ]
Still resolved to discover further answers, Lees decided to study Kabbalah and the Tree of Life . From here he proceeded to experiment with invocations from the Key of Solomon . Satisfied with the results, he proceeded to perform the 18-month working described in The Book of Abramelin by means of the Bornless Ritual . Claiming to have successfully invoked his Holy Guardian Angel , he turned his attention to ascending the ' Middle Pillar ' of the Tree of Life, culminating with an experience known as crossing the abyss . [ 83 ]
Then, in November 1976, Lees constructed [ 84 ] the "order & value of the English Alphabet." [ 85 ] Following this, Lees founded the O∴A∴A∴ in order to assist others in the pursuit of their own spiritual paths. [ 83 ] The first public report of the system known as English Qaballa (EQ) was published in 1979 by Ray Sherwin in an editorial in the final issue of his journal, The New Equinox . Lees subsequently assumed the role of publisher of The New Equinox and, starting in 1981, published additional material about the EQ system over the course of five issues of the journal, extending into 1982. [ 84 ]
In 1904, Aleister Crowley wrote out the text of the foundational document of his world-view, known as Liber AL vel Legis , The Book of the Law . In this text was the injunction found at verse 2:55; "Thou shalt obtain the order & value of the English Alphabet, thou shalt find new symbols to attribute them unto" which was understood by Crowley as referring to an English Qabalah yet to be developed or revealed. [ 86 ]
The "order & value" [ 85 ] constructed by James Lees lays the letters out on the grid superimposed on the page of manuscript of Liber AL on which this verse (Ch. III, v. 47) appears (sheet 16 of Chapter III). [ 85 ] Also appearing on this page are a diagonal line and a circled cross. The Book of the Law states that the book should only be printed with Crowley's hand-written version included, suggesting that there are mysteries in the "chance shape of the letters and their position to one another" of Crowley's handwriting. Whichever top-left to bottom-right diagonal is read the magickal order of the letters is obtained. [ 87 ]
Little further material on English Qaballa was published until the appearance of Jake Stratton-Kent's book, The Serpent Tongue: Liber 187 , in 2011. [ 88 ] This was followed in 2016 by The Magickal Language of the Book of the Law: An English Qaballa Primer by Cath Thompson. [ 89 ] The creation, exploration, and continuing research and development of the system up to 2010, by James Lees and members of his group in England, are detailed in her 2018 book, All This and a Book . [ 83 ]
Nema Andahadna (1939–2018) practiced and wrote about magic (magical working, as defined by Aleister Crowley) for over thirty years. In 1974, she claimed to have channelled a short book called Liber Pennae Praenumbra .
From her experience with Thelemic magic, she developed her own system of magic called "Maat Magick" which has the aim of transforming the human race. In 1979, she co-founded the Horus-Maat Lodge. The Lodge and her ideas have been featured in the writings of Kenneth Grant . [ 90 ] [ 91 ]
Her writings have appeared in many publications, including the Cincinnati Journal of Ceremonial Magick , Aeon , and Starfire . According to Donald Michael Kraig :
Nema has been one of the most influential occultists of the last quarter century although most occultists have never read her works. What Nema has done is influence those who have been writers and teachers. They, in turn, influenced the rest of us. [ 92 ] | https://en.wikipedia.org/wiki/James_Lees_(English_magician) |
James Lick (August 25, 1796 – October 1, 1876) was an American real estate investor, carpenter, piano builder, land baron, and patron of the sciences. The wealthiest man in California at the time of his death, Lick left the majority of his estate to social and scientific causes. [ 1 ]
James Lick was born to Pennsylvania Dutch parents in Stumpstown ( Fredericksburg ), Pennsylvania on August 25, 1796. [ 2 ] Lick's paternal grandfather, William Lük, was a German immigrant from the Palatinate , and served in the American Revolutionary War . [ 3 ] [ 4 ] William's son, John, anglicized the family name to Lick. [ 2 ]
The son of a carpenter , Lick began learning the craft at an early age. When he was twenty-one, he had a romance with Barbara Snavely, the mother of his only child, John Henry. They never married, and the romance failed. Lick left Stumpstown for Baltimore, Maryland , where he learned the art of piano making. He quickly mastered the skill, and moved to New York City and established his own shop. In 1821 Lick moved to Argentina , after learning that his pianos were being exported to South America .
Lick found his time in Buenos Aires to be difficult, because of his ignorance of Spanish and the turbulent political situation in the country. Despite this, his business thrived, and in 1825 Lick left Argentina to tour Europe for a year. On his return trip, his ship was captured by the Portuguese , and the passengers and crew were taken to Montevideo as prisoners of war . Lick escaped captivity and returned to Buenos Aires on foot.
In 1832, Lick returned to Stumpstown. He failed to reunite with Barbara Snavely and their son, and returned to Buenos Aires. He decided the political situation was too unstable and moved to Valparaíso , Chile . After four years, he again moved his business, this time to Lima , Peru .
In 1846, Lick returned to North America . Anticipating the Mexican–American War and the future annexation of California , he decided to settle there. A backlog of orders for his pianos delayed him 18 months, as his Mexican workers returned to their homes to join the Mexican Army. He finished the orders himself.
Lick arrived in San Francisco, California , in January 1848, [ 5 ] bringing with him his tools, work bench, $30,000 in gold (valued at approximately $2.75 million as of 2020), and 600 pounds (275 kilograms) of chocolate . The chocolate quickly sold, so Lick sent back word convincing his friend and neighbor in Peru , the confectioner Domingo Ghirardelli , to move to San Francisco, where he founded the Ghirardelli Chocolate Company . [ 6 ]
Upon his arrival, Lick began buying real estate in the small village of San Francisco. The discovery of gold at Sutter's Mill near Sacramento a few days after Lick's arrival in the future state began the California Gold Rush and created a housing boom in San Francisco, which grew from about one thousand residents in 1848 to over twenty thousand by 1850. Lick got a touch of "gold fever" and sought to mine the metal, but after a week decided his fortune was to be made by owning land, not digging in it. Lick continued buying land in San Francisco, and also began buying farmland in and around San Jose , where he planted orchards and built the largest flour mill in the state. He invited his son to join him there in 1854; however, the younger Lick suffered from poor health and returned to Pennsylvania in 1863.
In 1861, Lick began construction of a hotel , known as Lick House , [ 7 ] 41 Montgomery Street (Lick Street, [ 8 ] 111 Sutter Street [ 9 ] ), at the intersection with Sutter Street, in San Francisco. The hotel had a dining room that could seat 400, based on a similar room at the palace of Versailles . Lick House was considered the finest [ citation needed ] hotel west of the Mississippi River . The hotel was destroyed in the fire following the San Francisco earthquake of 1906 . The Hunter-Dulin Building was constructed 1925-1927. [ 10 ]
Following the construction, Lick returned to his San Jose orchards. In 1874, Lick suffered a massive stroke in the kitchen of his home in Santa Clara . The following morning, he was found by his employee, Thomas Fraser, and taken to Lick House, where he could be better cared for. At the time of his illness, his estates, outside his considerable area in Santa Clara County and San Francisco, included large holdings around Lake Tahoe , a large ranch in Los Angeles County , and all of Santa Catalina Island , [ 11 ] making Lick the richest man in California.
In the next three years, Lick spent his time determining how to dispense his fortune. He originally wanted to build giant statues of himself and his parents, and erect a pyramid larger than the Great Pyramid of Giza in his own honor in downtown San Francisco. Through the efforts of George Davidson, president of the California Academy of Sciences , Lick was persuaded to leave the greatest portion of his fortune to the establishment of a mountaintop observatory , with the largest, most powerful telescope yet built. [ 12 ]
In 1874, he placed $3,000,000 ($65,200,000 relative value in 2017) at the disposal of seven trustees, by whom the funds were to be applied to specific uses. He replaced the board in 1875 with Faxon Atherton , John Nightingale, Bernard D. Murphy and his son, John H. Lick. [ 13 ]
The principal divisions of the funds were: [ 14 ]
Lick had had an interest in astronomy since at least 1860, when he and George Madeira , the founder of the first observatory in California, spent several nights observing. They had also met again in 1873 and Lick said that Madeira's telescopes were the only ones he had ever used. In 1875, Thomas Fraser recommended a site at the summit of Mount Hamilton , near San Jose. Lick approved, on the condition that Santa Clara County build a "first-class" road to the site. The county agreed and the road was completed by the fall of 1876.
On October 1, 1876, Lick died in his room in Lick House, San Francisco. [ 15 ] In 1887, his body was moved to its final resting place, under the future home of the Great Lick Refracting Telescope . [ 3 ] | https://en.wikipedia.org/wiki/James_Lick |
Thomas James Marrow (born 23 November 1966) is a British scientist who is a professor of nuclear materials at the University of Oxford and holds the James Martin Chair in Energy Materials. [ 8 ] He specialises in physical metallurgy , micromechanics , and X-ray crystallography of engineering materials, mainly ceramic matrix composite and nuclear graphite . [ 9 ] [ 10 ] [ 4 ]
James Marrow was born on 23 November 1966 in Bromborough , Wirral to John Williams Marrow and Mary Elizabeth Marrow. [ 7 ] He attended Wirral Grammar School for Boys , [ 7 ] then graduated with a 1st Class Honours Master of Arts (M.A) in Natural Sciences (Materials Science) from the University of Cambridge in 1988, where he was a student at Clare College, Cambridge [ 4 ] before pursuing and completing a Doctor of Philosophy degree in 1991. [ 5 ] During his PhD, he studied the Fatigue mechanisms in embrittled duplex stainless steel and was supervised by Julia King . [ 11 ]
From 1992 to 1993, Marrow was appointed as postdoctoral research associate in the Department of Materials, University of Oxford , and a junior research fellow at Linacre College, Oxford , but moved with an Engineering and Physical Sciences Research Council (EPSRC) postdoctoral research fellowship to the School of Metallurgy and Materials, University of Birmingham . [ 4 ] [ 12 ] In 2001, he joined the Manchester Materials Science Centre, University of Manchester , as senior lecturer in physical metallurgy , where he became assistant director of Materials Performance Centre in 2002 and the director in 2009. [ 4 ] [ 12 ]
Marrow moved to the University of Oxford to become Oxford Martin School co-director of the school programme in Nuclear and Energy Materials from 2010 to 2015, [ 8 ] Professor in Energy Materials, Department of Materials, Oxford University, [ 6 ] and Fellow of Mansfield College, Oxford . [ 13 ] As of August 2023 [update] , Marrow is the Associate Head of Department of Materials (Teaching). [ 6 ]
Marrow is a council member of the UK Forum for Engineering Structural Integrity (FESI), [ 14 ] UK representative for the European Energy Research Alliance Joint Programme on Nuclear Materials, member (ex-chair) of the OECD-NEA Expert Group on Innovative Structural Materials, independent advisor to the UK Office of Nuclear Regulation on materials/structural integrity, and UK representative on Graphite for BEIS to the Generation IV International Forum. [ 13 ] [ 1 ] Marrow is the co-director of the Nuclear Research Centre (NRC), which is a joint venture between the University of Bristol and the University of Oxford to train new nuclear scientists and engineers. [ 15 ]
Marrow married Daiva Kojelyte in 1998 and he is a father of a son and a daughter. [ 7 ]
Marrow's research focuses on the degradation of structural materials , the role of microstructure , and the mechanisms of materials ageing . A key aspect is the investigation of fundamental mechanisms of damage accumulation - including irradiation - using novel materials characterisation techniques . This has concentrated recently on computed X-ray tomography and strain mapping by digital image correlation and digital volume correlation, together with X-ray and neutron diffraction . [ 3 ] He applies these techniques to study the degradation of Generation IV nuclear materials [ 9 ] such as graphite and silicon carbide composites, as well as new materials for electrical energy storage. [ 6 ] [ 1 ] [ 2 ]
Marrow is part of I'm a Scientist, Get me out of here! energy generation zone. [ 16 ] He has also been a key developer and academic consultant for the Dissemination of IT for the Promotion of Materials Science ( DoITPoMS ). [ 17 ] Global Cycle Network Technology (GCN Tech) interviewed James about carbon fibre fatigue and strain in 2022. [ 18 ] | https://en.wikipedia.org/wiki/James_Marrow |
James Maxime DuPont ( Edinburgh , Scotland , ( 1912-04-30 ) April 30, 1912 — Watchung , New Jersey , United States , ( 1991-07-01 ) July 1, 1991) was an American meteorite collector.
His father was Jean Rene Claudius Dupont, an analytical chemist. [ 1 ] At the time of his death, he was known for having the largest private collection of meteorites in the world, and after his death they were donated to the Planetary Studies Foundation, where they were known as the " James M. DuPont Meteorite Collection ". The impressive collection was gathered over thirty years while containing 1,719 individual meteorites, with a total mass over 500 kilograms. [ 2 ] These included several which were somewhat controversial and unrecognized, along with a few others that represented new finds awaiting classification. The Planetary Studies Foundation then donated them to the Field Museum of Natural History , the combined collection having had more than 1,700 meteors and an estimated value of $3 million, creating the world's largest non government meteorite collection. [ 3 ] [ 4 ]
As a resident of Watchung, New Jersey , DuPont founded an industrial thermoplastics company. [ 5 ] | https://en.wikipedia.org/wiki/James_Maxime_DuPont |
James N. Pitts Jr. (January 10, 1921 – June 19, 2014) was an American chemist and researcher known for his work in the fields of photochemistry and atmospheric chemistry . Pitts was a pioneer in the study of smog and air pollution , especially in Los Angeles County . [ 1 ] [ 2 ] Pitts co-founded the Statewide Air Pollution Research Center at the University of California, Riverside in 1961 and served as the center's director from 1970 to 1988. [ 3 ] He authored more than 400 scientific publications and four books on the subjects, especially smog. [ 3 ]
Pitts' research formed the basis for California 's air quality laws. [ 3 ] According to the chair of the Air Resources Board, Mary Nichols, "Jim Pitts was probably the single person most responsible for the understanding of what strategies we need to clean up Southern California 's air...He was able to explain all of this in English to policymakers so that they would be able to accept that it was going to take extensive and difficult actions to control emissions ." [ 3 ] He often invited state and federal officials to his smog chamber at UC Irvine, including Jerry Brown and Ronald Reagan , to demonstrate the effects of smog and air pollution. [ 3 ] In a common demonstration, Pitts would fill an Erlenmeyer flask with ozone and then twist a slice of lemon onto the flask. The ensuing chemical reaction, which quickly produced a fog, demonstrated the formation of smog in the atmosphere . [ 3 ]
Pitts refused funding from industry groups, which increased his center's credibility. [ 3 ] He was the recipient of numerous awards and recognitions from the California State Assembly , the United States Congress , the Coalition for Clean Air , the South Coast Air Quality Management District, and the California state air board. [ 1 ]
Pitts was born on January 10, 1921, in Salt Lake City , Utah , to Esther ( née Bengtson) and James N. Pitts. [ 2 ] The family moved to West Los Angeles when he was just six months old. [ 3 ] A high school teacher sparked his interest in chemistry during his junior year.
Pitts enrolled as a chemistry student at University of California, Los Angeles (UCLA) in 1939. [ 3 ] He left during World War II , joining a group of young scientists who conducted classified chemical warfare field tests. [ 3 ] Their work led to the development of more effective gas mask for Allied forces during the war. [ 3 ] He returned to UCLA, where he received a bachelor's degree in chemistry in 1945 and a doctorate in 1949. [ 3 ] Pitts initially worked as a faculty member of Northwestern University . He was at the time married to a woman by the name of Nancy Ann Quirt. James and Nancy had three daughters Linda, Christie and Beckie.
Pitts was hired as a founding professor at UC Riverside in 1954. [ 3 ]
Pitts married his second wife, UC Irvine chemist and professor Barbara Finlayson-Pitts in 1970. [ 3 ] He followed her to the University of California, Irvine in 1994, where the two collaborated of research and co-authored books and other publications. [ 3 ]
James Pitts died of natural causes at his home in Irvine, California , on June 19, 2014, at the age of 93. He was survived by his wife, Barbara Finlayson-Pitts, and three daughters, Linda Lee, Christie Hoffman and Beckie St. George. [ 3 ] He was also survived by five grandchildren Kristin Cohn, Brianna Hoffman, Trevin Hoffman, Mallory St George and Ryan Giordano. His great-grandchildren include Brandon, Kyle, Austin and Riley. | https://en.wikipedia.org/wiki/James_Pitts_(chemist) |
James Robert Brown FRSC (born 1949) is a Canadian philosopher of science . He is an emeritus professor of philosophy at the University of Toronto . In the philosophy of mathematics , he has advocated mathematical Platonism , visual reasoning , and in the philosophy of science he has defended scientific realism mostly against anti-realist views associated with social constructivism . He has also argued for the socialization of medical research (especially pharmaceutical research). He is largely known for his work on thought experiments .
Elected: Academy of Sciences Leopoldina (Deutsche Akademie der Naturforscher Leopoldina –
Nationale Akademie der Wissenschaften) 2004, Royal Society of Canada 2007, Académie Internationale de Philosophie des Sciences 2010
Brown was born in Montreal , Quebec . [ 1 ] He is married to the philosopher Kathleen Okruhlik. [ 2 ]
Books edited include:
This biography of a Canadian philosopher is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/James_Robert_Brown |
James Short FRS (10 June O.S. (21 June N.S. ) 1710 – 14 June 1768) was a Scottish mathematician and manufacturer of optical instruments , principally telescopes . During his 35-year career as a telescope-maker he produced approximately 1,360 scientific instruments. [ 1 ]
Short was born in Edinburgh in 1710 to Margaret Grierson and William Short, a carpenter . When he was orphaned at about the age of 10, he was accepted into the Heriot's Hospital , an orphanage, and at 12 transferred to the Royal High School where he excelled in the study of the classics . In 1726 he entered the University of Edinburgh to study divinity , however after being inspired by lectures given by professor of mathematics Colin Maclaurin , he transferred to astronomy and mathematics. [ 2 ]
In 1732 Maclaurin gave Short access to use his rooms in the university to work on for experiments in the construction of telescopes. Such was the quality of Short's instruments that in recognition of his skill he was elected as a Fellow of the Royal Society on 24 March 1737. [ 2 ] In Short's first telescopes the specula were made of glass, as suggested by James Gregory , however later he used metallic specula only, and thus succeeded in giving them true parabolic and elliptic shapes.
Short then adopted telescope-making as his profession, which he practised first in Edinburgh up until 1738, after which he transferred to London .
Almost all of Short's telescopes were of the Gregorian form , and some of them even today retain their original high polish and sharp definition.
In 1736 Queen Caroline requested him to instruct her second son, William , in mathematics.
In March 1737 Short was elected a Fellow of the Royal Society [ 3 ] and in 1758 became a foreign member of the Royal Swedish Academy of Sciences . He was a founder member of the Society for the Encouragement of Arts, Manufactures and Commerce in 1754.
Short died in Newington Butts , London in 1768, having made a considerable fortune from his profession. [ 2 ] | https://en.wikipedia.org/wiki/James_Short_(mathematician) |
James Simms (1828 – 4 September 1915) was an English instrument maker.
He succeeded his father William Simms (1793 – 1860) at the instrument making firm Troughton & Simms . The firm made instruments of various kinds, including notably astronomical instruments and telescopes .
For about ten years, until 1871, his partner in the firm was his cousin William Simms (1817 – 1907), who was the son of his uncle James, the brother of his father William. After 1871 he was sole proprietor. After his death, he was succeeded in the firm by his sons, who were named William and James.
This English biographical article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/James_Simms_(instrument_maker) |
James Walter Mayer (April 24, 1930 – June 14, 2013 [ 1 ] [ 2 ] ) was an applied physicist , who was active in the field of ion-solid interactions. His accomplishments played a critical role in the development of the solid-state particle detector ; the field of ion beam analysis of materials, and the application of ion implantation to semiconductors .
Mayer was born on April 24, 1930 in Chicago. He went to Purdue University to earn a Bachelor of Science degree in mechanical engineering in 1952. [ 3 ] He entered the graduate program in physics at Purdue to work under solid-state physicist Ben R. Gossick. A short time later, Mayer had to change research advisors when Gossick decided to leave Purdue. Karl Lark-Horovitz became Mayer's new advisor upon Gossick's departure. Before Mayer was able to complete his thesis work, department chair Hubert M. James became Mayer's third thesis supervisor after Lark-Horovitz's death in 1958. Mayer was able to earn his PhD in 1960. [ 4 ]
He gained a PhD degree in physics from Purdue University and worked at Hughes Research Laboratories before moving in 1967 to the California Institute of Technology as professor of electrical engineering. He joined Cornell University as professor of materials science and engineering in 1980, and was made director of the microscience and technology program in 1989. Moving to Arizona State University in 1992, he served as director of the Center for Solid State Science before being appointed regents professor (1994) and P.V. Galvin Professor of Science & Engineering (1997). [ 5 ]
It was known in the 1950s that semiconductor p-n junctions responded to alpha particles by producing voltage pulses. However, the common method of determining the energy spectrum of energetic particles at that time relied on the use of very large and cumbersome magnetic spectrometers and ionization chambers . It was at this time in the mid to late 1950s that James Mayer demonstrated the first semiconductor, broad area, spectrometer which measured the energies of the particles rather than just detecting their impact. Mayer's discovery was that the ionization of Si and Ge by charged particles (as well as X-rays ) could be used, in a small, compact device, to collect the electrons and holes that were created and thereby measure the energy of the incident particles.
The concept of the surface-barrier particle detector that Mayer first developed served as a cornerstone for the rapid development of
numerous research areas. Because of its small size and compactness, the surface-barrier particle detector almost immediately started replacing many of the cumbersome detectors in use at that time, i.e. magnetic spectrometers and ionization chambers, revolutionizing low energy nuclear structure physics almost overnight. These semiconductor spectrometers led to the practical development of many modern materials analysis techniques that have wide spread use today, such as X-ray fluorescence and ion beam analysis of materials, including Rutherford backscattering , ion channeling, and X-ray spectrometry based on alpha particle sources.
Mayer played a pivotal role in the application of particle detectors to the fledgling field of ion beam analysis (often referred to as Rutherford Backscattering Spectrometry or RBS) and the development of this field into a major analytical tool. He went on to define many of the advances in thin film science of the 1970s and 80s, including thin film reactions and kinetics (especially of metal silicides), solid phase regrowth of semiconductors, ion beam mixing for the formation of metastable alloys, implantation disorder and impurity location in semiconductors, and the study of thin dielectric films.
In the rapid surge of industrial interest in ion implantation of Si, starting around 1965, Mayer and his coworkers used ion channeling to understand defect production during dopant ion implantation into Si, the recovery of this damage, and the activation of dopants during subsequent anneals, thereby making ion implantation a viable tool for the production of integrated circuits . In 1967, he was chosen by Academic Press to author the first monograph on Ion Implantation of Semiconductors and by 1970 ion implantation first began being used in the commercial production of integrated circuits.
His work resulted in more than 750 papers and 12 books which have garnered in excess of 17,000 citations (ISI listed him as one of the 1000 most-cited Contemporary Scientists between 1965 and 1978). He mentored 40 PhD students and numerous postdoctoral scholars during his academic career at Caltech , Cornell and Arizona State University .
He was elected a Fellow of the American Physical Society in 1972. [ 6 ]
Mayer was awarded the 1981 Von Hippel Award by the Materials Research Society . [ 7 ]
He was elected to the National Academy of Engineering in 1984, in the Materials section. [ 8 ] | https://en.wikipedia.org/wiki/James_W._Mayer |
James W. Mitchell is an African American chemist and was the David and Lucille Packard Professor of Material Science at Howard University .
James W. Mitchell was born on November 16, 1943, in Durham, North Carolina . He was one of five children born to Willie and Eunice Mitchell. [ 1 ] His interest in chemistry began in 1960 during a summer program at North Carolina Central University that was funded by the National Science Foundation. [ 1 ]
Despite suffering financial hardships, he was able to fund his education through a scholarship and by working on-campus at North Carolina A&T State University . [ 1 ] He earned his B.S. degree in Chemistry in 1965. He pursued his studies in Analytical Chemistry, receiving his Ph.D. degree in 1970 from Iowa State University . [ 2 ] [ 3 ]
Mitchell's first job after receiving his Ph.D. was with AT&T Bell Laboratories in Murray Hill, New Jersey . Initially starting as a member of the technical staff, he quickly rose through the ranks to become Head of the Analytical Chemistry Research Department in 1975. [ 4 ] During his time there, he also became one of the founders for the Association of Black Laboratory Employees. He supervised the Inorganic Analytical Chemistry Research Group and though his leading, made the Department a renowned Laboratory Research organization worldwide. [ 2 ] He was first Black Bell Labs Fellow and the first black director and vice president of research. [ 4 ] In 2002 he began working at Howard University as the David and Lucille Packard Professor of Materials Science and Chemical Engineering. He also co-wrote a book, "Contamination Control in Trace Analysis." He was Director of the CREST Nanoscale Analytical Sciences Research and Education Center. [ 2 ] He has published over 60 scientific papers, and patented several innovative processes. [ 4 ]
As a chemist, he wrote approximately 100 articles. Mitchell developed processes, such as "on-demand" reagent generation, which improved the production of high-purity materials for optical fibers and semiconductors. He established benchmarks in materials purity and quality, enabling transformative advancements in optical communication and high-power laser technologies. He also led research in diamond material development, introducing methods to enhance diamond properties for industrial applications. [ 4 ]
Mitchell received the Percy L. Julian Research Award and the Pharmacia Industrial Analytical Chemistry Award. [ 4 ] He was elected to the National Academy of Engineering in 1989. [ 5 ] [ 3 ] In 1999, he was awarded the Lifetime Achievement in Industry Award from the National Society of Black Engineers . [ 2 ] He was named the 1993 Black Engineer of the Year by US Black Engineer magazine for his contributions to analytical chemistry and materials engineering. [ 6 ] | https://en.wikipedia.org/wiki/James_W._Mitchell |
The James Webb Space Telescope ( JWST ) is a space telescope designed to conduct infrared astronomy . As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, distant , or faint for the Hubble Space Telescope . [ 9 ] This enables investigations across many fields of astronomy and cosmology , such as observation of the first stars and the formation of the first galaxies , and detailed atmospheric characterization of potentially habitable exoplanets . [ 10 ] [ 11 ] [ 12 ]
Although the Webb's mirror diameter is 2.7 times larger than that of the Hubble Space Telescope, it produces images of comparable resolution because it observes in the longer-wavelength infrared spectrum. The longer the wavelength of the spectrum, the larger the information-gathering surface required (mirrors in the infrared spectrum or antenna area in the millimeter and radio ranges) for an image comparable in clarity to the visible spectrum of the Hubble Space Telescope.
The Webb was launched on 25 December 2021 on an Ariane 5 rocket from Kourou , French Guiana. In January 2022 it arrived at its destination, a solar orbit near the Sun–Earth L 2 Lagrange point , about 1.5 million kilometers (930,000 mi) from Earth. The telescope's first image was released to the public on 11 July 2022. [ 13 ]
The U.S. National Aeronautics and Space Administration (NASA) led Webb's design and development and partnered with two main agencies: the European Space Agency (ESA) and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center in Maryland managed telescope development, while the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates Webb. The primary contractor for the project was Northrop Grumman .
The telescope is named after James E. Webb , who was the administrator of NASA from 1961 to 1968 during the Mercury , Gemini , and Apollo programs.
Webb's primary mirror consists of 18 hexagonal mirror segments made of gold -plated beryllium , which together create a 6.5-meter-diameter (21 ft) mirror, compared with Hubble's 2.4 m (7 ft 10 in). This gives Webb a light-collecting area of about 25 m 2 (270 sq ft), about six times that of Hubble. Unlike Hubble, which observes in the near ultraviolet and visible (0.1 to 0.8 μm ), and near infrared (0.8–2.5 μm) [ 14 ] spectra, Webb observes a lower frequency range, from long-wavelength visible light (red) through mid-infrared (0.6–28.5 μm). [ 15 ] The telescope must be kept extremely cold, below 50 K (−223 °C; −370 °F), so that the infrared light emitted by the telescope itself does not interfere with the collected light. Its five-layer sunshield protects it from warming by the Sun, Earth, and Moon.
Initial designs for the telescope, then named the Next Generation Space Telescope, began in 1996. Two concept studies were commissioned in 1999, for a potential launch in 2007 and a US$1 billion budget. The program was plagued with enormous cost overruns and delays. A major redesign was accomplished in 2005, with construction completed in 2016, followed by years of exhaustive testing, at a total cost of US$10 billion.
The mass of the James Webb Space Telescope (JWST) is about half that of the Hubble Space Telescope . Webb has a 6.5-meter-diameter (21-foot) gold -coated beryllium primary mirror made up of 18 separate hexagonal mirrors. The mirror has a polished area of 26.3 m 2 (283 sq ft), of which 0.9 m 2 (9.7 sq ft) is obscured by the secondary support struts, [ 16 ] giving a total collecting area of 25.4 m 2 (273 sq ft). This is over six times larger than the collecting area of Hubble's 2.4 m (7.9 ft) diameter mirror, which has a collecting area of 4.0 m 2 (43 sq ft). The mirror has a gold coating to provide infrared reflectivity and this is covered by a thin layer of glass for durability. [ 17 ]
Webb is designed primarily for near-infrared astronomy , but can also see orange and red visible light, as well as the mid-infrared region, depending on the instrument being used. [ 10 ] [ 11 ] It can detect objects up to 100 times fainter than Hubble can, and objects much earlier in the history of the universe , back to redshift z≈20 (about 180 million years cosmic time after the Big Bang ). [ 18 ] For comparison, the earliest stars are thought to have formed between z≈30 and z≈20 (100–180 million years cosmic time), [ 19 ] and the first galaxies may have formed around redshift z≈15 (about 270 million years cosmic time). Hubble is unable to see further back than very early reionization [ 20 ] [ 21 ] at about z≈11.1 (galaxy GN-z11 , 400 million years cosmic time). [ 22 ] [ 23 ] [ 18 ]
The design emphasizes the near to mid-infrared for several reasons:
Ground-based telescopes must look through Earth's atmosphere , which is opaque in many infrared bands (see figure at right). Even where the atmosphere is transparent, many of the target chemical compounds, such as water, carbon dioxide, and methane, also exist in the Earth's atmosphere, vastly complicating analysis. Existing space telescopes such as Hubble cannot study these bands since their mirrors are insufficiently cool (the Hubble mirror is maintained at about 15 °C [288 K; 59 °F]) which means that the telescope itself radiates strongly in the relevant infrared bands. [ 24 ]
Webb can also observe objects in the Solar System at an angle of more than 85° from the Sun and having an apparent angular rate of motion less than 0.03 arc seconds per second. [ a ] This includes Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, their satellites , and comets , asteroids and minor planets at or beyond the orbit of Mars . Webb has the near-IR and mid-IR sensitivity to be able to observe virtually all known Kuiper Belt Objects . [ 19 ] [ 28 ] In addition, it can observe opportunistic and unplanned targets within 48 hours of a decision to do so, such as supernovae and gamma ray bursts . [ 19 ]
Webb operates in a halo orbit , circling around a point in space known as the Sun–Earth L 2 Lagrange point , approximately 1,500,000 km (930,000 mi) beyond Earth's orbit around the Sun. Its actual position varies between about 250,000 and 832,000 km (155,000–517,000 mi) from L 2 as it orbits, keeping it out of both Earth and Moon's shadow. By way of comparison, Hubble orbits 550 km (340 mi) above Earth's surface, and the Moon is roughly 400,000 km (250,000 mi) from Earth. Objects near this Sun–Earth L 2 point can orbit the Sun in synchrony with the Earth, allowing the telescope to remain at a roughly constant distance [ 29 ] with continuous orientation of its sunshield and equipment bus toward the Sun , Earth and Moon . Combined with its wide shadow-avoiding orbit, the telescope can simultaneously block incoming heat and light from all three of these bodies and avoid even the smallest changes of temperature from Earth and Moon shadows that would affect the structure, yet still maintain uninterrupted solar power and Earth communications on its sun-facing side. This arrangement keeps the temperature of the spacecraft constant and below the 50 K (−223 °C; −370 °F) necessary for faint infrared observations. [ 30 ] [ 31 ]
To make observations in the infrared spectrum , Webb must be kept under 50 K (−223.2 °C; −369.7 °F); otherwise, infrared radiation from the telescope itself would overwhelm its instruments. Its large sunshield blocks light and heat from the Sun, Earth, and Moon, and its position near the Sun–Earth L 2 keeps all three bodies on the same side of the spacecraft at all times. [ 32 ] Its halo orbit around the L 2 point avoids the shadow of the Earth and Moon, maintaining a constant environment for the sunshield and solar arrays. [ 29 ] The resulting stable temperature for the structures on the dark side is critical to maintaining precise alignment of the primary mirror segments. [ 30 ]
The sunshield consists of five layers, each approximately as thin as a human hair. [ 33 ] Each layer is made of Kapton E film, coated with aluminum on both sides. The two outermost layers have an additional coating of doped silicon on the Sun-facing sides, to better reflect the Sun's heat back into space. [ 30 ] Accidental tears of the delicate film structure during deployment testing in 2018 led to further delays to the telescope deployment. [ 34 ]
The sunshield was designed to be folded twelve times so that it would fit within the Ariane 5 rocket's payload fairing , which is 4.57 m (15.0 ft) in diameter, and 16.19 m (53.1 ft) long. The shield's fully deployed dimensions were planned as 14.162 m × 21.197 m (46.46 ft × 69.54 ft). [ 35 ]
Keeping within the shadow of the sunshield limits the field of regard of Webb at any given time. The telescope can see 40 percent of the sky from any one position, but can see all of the sky over a period of six months. [ 36 ]
Webb's primary mirror is a 6.5 m (21 ft)-diameter gold-coated beryllium reflector with a collecting area of 25.4 m 2 (273 sq ft). If it had been designed as a single, large mirror, it would have been too large for existing launch vehicles. The mirror is therefore composed of 18 hexagonal segments (a technique pioneered by Guido Horn d'Arturo ), which unfolded after the telescope was launched. Image plane wavefront sensing through phase retrieval is used to position the mirror segments in the correct location using precise actuators . Subsequent to this initial configuration, they only need occasional updates every few days to retain optimal focus. [ 37 ] This is unlike terrestrial telescopes, for example the Keck telescopes , which continually adjust their mirror segments using active optics to overcome the effects of gravitational and wind loading. [ 38 ] The Webb telescope uses 132 small actuation motors to position and adjust the optics. [ 39 ] The actuators can position the mirror with 10 nanometer accuracy. [ 40 ]
Webb's optical design is a three-mirror anastigmat , [ 41 ] which makes use of curved secondary and tertiary mirrors to deliver images that are free from optical aberrations over a wide field. The secondary mirror is 0.74 m (2.4 ft) in diameter. In addition, there is a fine steering mirror which can adjust its position many times per second to provide image stabilization . Point light sources in images taken by Webb have six diffraction spikes plus two fainter ones, due to the hexagonal shape of the primary mirror segments. [ 42 ]
The Integrated Science Instrument Module (ISIM) is a framework that provides electrical power, computing resources, cooling capability as well as structural stability to the Webb telescope. It is made with bonded graphite-epoxy composite attached to the underside of Webb's telescope structure. The ISIM holds the four science instruments and a guide camera. [ 43 ]
NIRCam and MIRI feature starlight-blocking coronagraphs for observation of faint targets such as extrasolar planets and circumstellar disks very close to bright stars. [ 49 ]
The spacecraft bus is the primary support component of the JWST, hosting a multitude of computing, communication, electric power, propulsion, and structural parts. [ 54 ] Along with the sunshield, it forms the spacecraft element of the space telescope . [ 55 ] [ 56 ] The spacecraft bus is on the Sun-facing "warm" side of the sunshield and operates at a temperature of about 300 K (27 °C; 80 °F). [ 55 ]
The structure of the spacecraft bus has a mass of 350 kg (770 lb), and must support the 6,200 kg (13,700 lb) space telescope. It is made primarily of graphite composite material. [ 57 ] The assembly was completed in California in 2015. It was integrated with the rest of the space telescope leading to its 2021 launch. The spacecraft bus can rotate the telescope with a pointing precision of one arcsecond , and isolates vibration to two milliarcseconds. [ 58 ]
Webb has two pairs of rocket engines (one pair for redundancy) to make course corrections on the way to L 2 and for station keeping – maintaining the correct position in the halo orbit. Eight smaller thrusters are used for attitude control – the correct pointing of the spacecraft. [ 59 ] The engines use hydrazine fuel (159 liters or 42 U.S. gallons at launch) and dinitrogen tetroxide as oxidizer (79.5 liters or 21.0 U.S. gallons at launch). [ 60 ]
Webb is not intended to be serviced in space. A crewed mission to repair or upgrade the observatory, as was done for Hubble, would not be possible, [ 61 ] and according to NASA Associate Administrator Thomas Zurbuchen , despite best efforts, an uncrewed remote mission was found to be beyond available technology at the time Webb was designed. [ 62 ] During the long Webb testing period, NASA officials referred to the idea of a servicing mission, but no plans were announced. [ 63 ] [ 64 ] Since the successful launch, NASA has stated that nevertheless limited accommodation was made to facilitate future servicing missions. These accommodations included precise guidance markers in the form of crosses on the surface of Webb, for use by remote servicing missions, as well as refillable fuel tanks, removable heat protectors, and accessible attachment points. [ 65 ] [ 62 ]
Webb uses a modified version of JavaScript , called Nombas ScriptEase 5.00e, for its operations; it follows the ECMAScript standard and "allows for a modular design flow, where on-board scripts call lower-level scripts that are defined as functions". Furthermore, "The script interpreter is run by the flight software, which is written in C++ . The flight software operates the spacecraft and the science instruments." [ 66 ]
The desire for a large infrared space telescope traces back decades. In the United States, the Space Infrared Telescope Facility (later called the Spitzer Space Telescope ) was planned while the Space Shuttle was in development, and the potential for infrared astronomy was acknowledged at that time. [ 67 ] Unlike ground telescopes, space observatories are free from atmospheric absorption of infrared light. Space observatories opened a "new sky" for astronomers.
However, there is a challenge involved in the design of infrared telescopes: they need to stay extremely cold, and the longer the wavelength of infrared, the colder they need to be. If not, the background heat of the device itself overwhelms the detectors, making it effectively blind. This can be overcome by careful design. One method is to put the key instruments in a dewar with an extremely cold substance, such as liquid helium . The coolant will slowly vaporize, limiting the lifetime of the instrument from as short as a few months to a few years at most. [ 24 ]
It is also possible to maintain a low temperature by designing the spacecraft to enable near-infrared observations without a supply of coolant, as with the extended missions of the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer , which operated at reduced capacity after coolant depletion. Another example is Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument, which started out using a block of nitrogen ice that depleted after a couple of years, but was then replaced during the STS-109 servicing mission with a cryocooler that worked continuously. The Webb Space Telescope is designed to cool itself without a dewar, using a combination of sunshields and radiators, with the mid-infrared instrument using an additional cryocooler. [ 68 ]
Webb's delays and cost increases have been compared to those of its predecessor, the Hubble Space Telescope . When Hubble formally started in 1972, it had an estimated development cost of US$300 million (equivalent to $2,255,131,000 in 2024), but by the time it was sent into orbit in 1990, the cost was about four times that. In addition, new instruments and servicing missions increased the cost to at least US$9 billion by 2006 [ 72 ] (equivalent to $14,037,801,000 in 2024).
Discussions of a Hubble follow-on started in the 1980s, but serious planning began in the early 1990s. [ 75 ] The Hi-Z telescope concept was developed between 1989 and 1994: [ 76 ] a fully baffled [ b ] 4 m (13 ft) aperture infrared telescope that would recede to an orbit at 3 Astronomical unit (AU). [ 77 ] This distant orbit would have benefited from reduced light noise from zodiacal dust . [ 77 ] Other early plans called for a NEXUS precursor telescope mission. [ 78 ] [ 79 ]
Correcting the flawed optics of the Hubble Space Telescope (HST) in its first years played a significant role in the birth of Webb. [ 80 ] In 1993, NASA conducted STS-61 , the Space Shuttle mission that replaced HST's camera and installed a retrofit for its imaging spectrograph to compensate for the spherical aberration in its primary mirror .
The HST & Beyond Committee was formed in 1994 "to study possible missions and programs for optical-ultraviolet astronomy in space for the first decades of the 21st century." [ 81 ] Emboldened by HST's success, its 1996 report explored the concept of a larger and much colder, infrared-sensitive telescope that could reach back in cosmic time to the birth of the first galaxies. This high-priority science goal was beyond the HST's capability because, as a warm telescope, it is blinded by infrared emission from its own optical system. In addition to recommendations to extend the HST mission to 2005 and to develop technologies for finding planets around other stars, NASA embraced the chief recommendation of HST & Beyond [ 82 ] for a large, cold space telescope (radiatively cooled far below 0 °C), and began the planning process for the future Webb telescope.
Preparation for the 2000 Astronomy and Astrophysics Decadal Survey (a literature review produced by the United States National Research Council that includes identifying research priorities and making recommendations for the upcoming decade) included further development of the scientific program for what became known as the Next Generation Space Telescope, [ 83 ] and advancements in relevant technologies by NASA. As it matured, studying the birth of galaxies in the young universe , and searching for planets around other stars – the prime goals coalesced as "Origins" by HST & Beyond became prominent. [ citation needed ]
As hoped, the NGST received the highest ranking in the 2000 Decadal Survey. [ 84 ]
An administrator of NASA , Dan Goldin , coined the phrase " faster, better, cheaper ", and opted for the next big paradigm shift for astronomy, namely, breaking the barrier of a single mirror. That meant going from "eliminate moving parts" to "learn to live with moving parts" (i.e. segmented optics). With the goal to reduce mass density tenfold, silicon carbide with a very thin layer of glass on top was first looked at, but beryllium was selected at the end. [ 75 ]
The mid-1990s era of "faster, better, cheaper" produced the NGST concept, with an 8 m (26 ft) aperture to be flown to L 2 , roughly estimated to cost US$500 million. [ 85 ] In 1997, NASA worked with the Goddard Space Flight Center, [ 86 ] Ball Aerospace & Technologies , [ 87 ] and TRW [ 88 ] to conduct technical requirement and cost studies of the three different concepts, and in 1999 selected Lockheed Martin [ 89 ] and TRW for preliminary concept studies. [ 90 ] Launch was at that time planned for 2007, but the launch date was pushed back many times (see table further down ).
In 2002, the project was renamed after NASA's second administrator (1961–1968), James E. Webb (1906–1992). [ 91 ] Webb led the agency during the Apollo program and established scientific research as a core NASA activity. [ 92 ]
In 2003, NASA awarded TRW the US$824.8 million prime contract for Webb. The design called for a de-scoped 6.1 m (20 ft) primary mirror and a launch date of 2010. [ 93 ] Later that year, TRW was acquired by Northrop Grumman in a hostile bid and became Northrop Grumman Space Technology. [ 90 ]
Development was managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, with John C. Mather as its project scientist. The primary contractor was Northrop Grumman Aerospace Systems, responsible for developing and building the spacecraft element, which included the satellite bus , sunshield, Deployable Tower Assembly (DTA) which connects the Optical Telescope Element to the spacecraft bus, and the Mid Boom Assembly (MBA) which helps to deploy the large sunshields on orbit, [ 94 ] while Ball Aerospace & Technologies was subcontracted to develop and build the OTE itself, and the Integrated Science Instrument Module (ISIM). [ 43 ]
Cost growth revealed in spring 2005 led to an August 2005 re-planning. [ 95 ] The primary technical outcomes of the re-planning were significant changes in the integration and test plans, a 22-month launch delay (from 2011 to 2013), and elimination of system-level testing for observatory modes at wavelengths shorter than 1.7 μm. Other major features of the observatory were unchanged. Following the re-planning, the project was independently reviewed in April 2006. [ citation needed ]
In the 2005 re-plan, the life-cycle cost of the project was estimated at US$4.5 billion. This comprised approximately US$3.5 billion for design, development, launch and commissioning, and approximately US$1.0 billion for ten years of operations. [ 95 ] The ESA agreed in 2004 to contributing about €300 million, including the launch. [ 96 ] The CSA pledged CA$39 million in 2007 [ 97 ] and in 2012 delivered its contributions in equipment to point the telescope and detect atmospheric conditions on distant planets. [ 98 ]
In January 2007, nine of the ten technology development items in the project successfully passed a Non-Advocate Review. [ 99 ] These technologies were deemed sufficiently mature to retire significant risks in the project. The remaining technology development item (the MIRI cryocooler) completed its technology maturation milestone in April 2007. This technology review represented the beginning step in the process that ultimately moved the project into its detailed design phase (Phase C). By May 2007, costs were still on target. [ 100 ] In March 2008, the project successfully completed its Preliminary Design Review (PDR). In April 2008, the project passed the Non-Advocate Review. Other passed reviews include the Integrated Science Instrument Module review in March 2009, the Optical Telescope Element review completed in October 2009, and the Sunshield review completed in January 2010. [ 101 ]
In April 2010, the telescope passed the technical portion of its Mission Critical Design Review (MCDR). Passing the MCDR signified the integrated observatory can meet all science and engineering requirements for its mission. [ 102 ] The MCDR encompassed all previous design reviews. The project schedule underwent review during the months following the MCDR, in a process called the Independent Comprehensive Review Panel, which led to a re-plan of the mission aiming for a 2015 launch, but as late as 2018. By 2010, cost over-runs were impacting other projects, though Webb itself remained on schedule. [ 103 ]
By 2011, the Webb project was in the final design and fabrication phase (Phase C).
Assembly of the hexagonal segments of the primary mirror, which was done via robotic arm, began in November 2015 and was completed on 3 February 2016. The secondary mirror was installed on 3 March 2016. [ 104 ] [ 105 ] Final construction of the Webb telescope was completed in November 2016, after which extensive testing procedures began. [ 106 ]
In March 2018, NASA delayed Webb's launch an additional two years to May 2020 after the telescope's sunshield ripped during a practice deployment and the sunshield's cables did not sufficiently tighten. In June 2018, NASA delayed the launch by an additional 10 months to March 2021, based on the assessment of the independent review board convened after the failed March 2018 test deployment. [ 107 ] The review identified that Webb launch and deployment had 344 potential single-point failures – tasks that had no alternative or means of recovery if unsuccessful, and therefore had to succeed for the telescope to work. [ 108 ] In August 2019, the mechanical integration of the telescope was completed, something that was scheduled to be done 12 years before in 2007. [ 109 ]
After construction was completed, Webb underwent final tests at Northrop Grumman's historic Space Park in Redondo Beach, California. [ 110 ] A ship carrying the telescope left California on 26 September 2021, passed through the Panama Canal , and arrived in French Guiana on 12 October 2021. [ 111 ]
NASA's lifetime cost for the project is [ when? ] expected to be US$9.7 billion, of which US$8.8 billion was spent on spacecraft design and development and US$861 million is planned to support five years of mission operations. [ 112 ] Representatives from ESA and CSA stated their project contributions amount to approximately €700 million and CA$200 million, respectively. [ 113 ]
A study in 1984 by the Space Science Board estimated that to build a next-generation infrared observatory in orbit would cost US$4 billion (US$7B in 2006 dollars, or $10B in 2020 dollars). [ 72 ] While this came close to the final cost of Webb, the first NASA design considered in the late 1990s was more modest, aiming for a $1 billion price tag over 10 years of construction. Over time this design expanded, added funding for contingencies, and had scheduling delays.
By 2008, when the project entered preliminary design review and was formally confirmed for construction, over US$1 billion had already been spent on developing the telescope, and the total budget was estimated at US$5 billion (equivalent to $8.05 billion in 2024). [ 126 ] In summer 2010, the mission passed its Critical Design Review (CDR) with excellent grades on all technical matters, but schedule and cost slips at that time prompted Maryland U.S. Senator Barbara Mikulski to call for external review of the project. The Independent Comprehensive Review Panel (ICRP) chaired by J. Casani (JPL) found that the earliest possible launch date was in late 2015 at an extra cost of US$1.5 billion (for a total of US$6.5 billion). They also pointed out that this would have required extra funding in FY2011 and FY2012 and that any later launch date would lead to a higher total cost. [ 120 ]
On 6 July 2011, the United States House of Representatives' appropriations committee on Commerce, Justice, and Science moved to cancel the James Webb project by proposing an FY2012 budget that removed US$1.9 billion from NASA's overall budget, of which roughly one quarter was for Webb. [ 127 ] [ 128 ] [ 129 ] [ 130 ] US$3 billion had been spent and 75% of its hardware was in production. [ 131 ] This budget proposal was approved by subcommittee vote the following day. The committee charged that the project was "billions of dollars over budget and plagued by poor management". [ 127 ] In response, the American Astronomical Society issued a statement in support of Webb, [ 132 ] as did Senator Mikulski. [ 133 ] A number of editorials supporting Webb appeared in the international press during 2011 as well. [ 127 ] [ 134 ] [ 135 ] In November 2011, Congress reversed plans to cancel Webb and instead capped additional funding to complete the project at US$8 billion. [ 136 ]
While similar issues had affected other major NASA projects such as the Hubble telescope, some scientists expressed concerns about growing costs and schedule delays for the Webb telescope, worrying that its budget might be competing with those of other space science programs. [ 137 ] [ 138 ] A 2010 Nature article described Webb as "the telescope that ate astronomy". [ 139 ] NASA continued to defend the budget and timeline of the program to Congress. [ 138 ] [ 140 ]
In 2018, Gregory L. Robinson was appointed as the new director of the Webb program. [ 141 ] Robinson was credited with raising the program's schedule efficiency (how many measures were completed on time) from 50% to 95%. [ 141 ] For his role in improving the performance of the Webb program, Robinsons's supervisor, Thomas Zurbuchen , called him "the most effective leader of a mission I have ever seen in the history of NASA." [ 141 ] In July 2022, after Webb's commissioning process was complete and it began transmitting its first data, Robinson retired following a 33-year career at NASA. [ 142 ]
On 27 March 2018, NASA pushed back the launch to May 2020 or later, [ 123 ] with a final cost estimate to come after a new launch window was determined with the ESA. [ 143 ] [ 144 ] [ 145 ] In 2019, its mission cost cap was increased by US$800 million. [ 146 ] After launch windows were paused in 2020 due to the COVID-19 pandemic , [ 147 ] Webb was launched at the end of 2021, with a total cost of just under US$10 billion.
No single area drove the cost. For future large telescopes, there are five major areas critical to controlling overall cost: [ 148 ]
NASA, ESA and CSA have collaborated on the telescope since 1996. ESA's participation in construction and launch was approved by its members in 2003 and an agreement was signed between ESA and NASA in 2007. In exchange for full partnership, representation and access to the observatory for its astronomers, ESA is providing the NIRSpec instrument, the Optical Bench Assembly of the MIRI instrument, an Ariane 5 ECA launcher, and manpower to support operations. [ 96 ] [ 149 ] The CSA provided the Fine Guidance Sensor and the Near-Infrared Imager Slitless Spectrograph and manpower to support operations. [ 150 ]
Several thousand scientists, engineers, and technicians spanning 15 countries have contributed to the build, test and integration of Webb. [ 151 ] A total of 258 companies, government agencies, and academic institutions participated in the pre-launch project; 142 from the United States, 104 from 12 European countries (including 21 from the U.K., 16 from France, 12 from Germany and 7 international), [ 152 ] and 12 from Canada. [ 151 ] Other countries as NASA partners, such as Australia, were involved in post-launch operation. [ 153 ]
Participating countries:
In 2002, NASA administrator (2001–2004) Sean O'Keefe made the decision to name the telescope after James E. Webb , the administrator of NASA from 1961 to 1968 during the Mercury , Gemini , and much of the Apollo programs . [ 91 ] [ 92 ]
In 2015, concerns were raised around Webb's possible role in the lavender scare , the mid-20th-century persecution by the U.S. government targeting homosexuals in federal employment . [ 154 ] [ 155 ] In 2022, NASA released a report of an investigation, [ 156 ] based on an examination of more than 50,000 documents. The report found "no available evidence directly links Webb to any actions or follow-up related to the firing of individuals for their sexual orientation", either in his time in the State Department or at NASA. [ 157 ] [ 158 ]
The James Webb Space Telescope has four key goals:
These goals can be accomplished more effectively by observation in near-infrared light rather than light in the visible part of the spectrum. For this reason, Webb's instruments will not measure visible or ultraviolet light like the Hubble Telescope, but will have a much greater capacity to perform infrared astronomy . Webb will be sensitive to a range of wavelengths from 0.6 to 28 μm (corresponding respectively to orange light and deep infrared radiation at about 100 K or −173 °C).
Webb may be used to gather information on the dimming light of star KIC 8462852 , which was discovered in 2015, and has some abnormal light-curve properties. [ 160 ]
Additionally, it will be able to tell if an exoplanet has methane in its atmosphere, allowing astronomers to determine whether or not the methane is a biosignature . [ 161 ] [ 162 ]
Webb orbits the Sun near the second Lagrange point (L 2 ) of the Sun–Earth system, which is 1,500,000 km (930,000 mi) farther from the Sun than the Earth's orbit, and about four times farther than the Moon's orbit. Normally an object circling the Sun farther out than Earth would take longer than one year to complete its orbit. But near the L 2 point, the combined gravitational pull of the Earth and the Sun allow a spacecraft to orbit the Sun in the same time that it takes the Earth. Staying close to Earth allows data rates to be much faster for a given size of antenna.
The telescope circles about the Sun–Earth L 2 point in a halo orbit , which is inclined with respect to the ecliptic , has a radius varying between about 250,000 km (160,000 mi) and 832,000 km (517,000 mi), and takes about half a year to complete. [ 29 ] Since L 2 is just an equilibrium point with no gravitational pull, a halo orbit is not an orbit in the usual sense: the spacecraft is actually in orbit around the Sun, and the halo orbit can be thought of as controlled drifting to remain in the vicinity of the L 2 point. [ 163 ] This requires some station-keeping : around 2.5 m/s per year [ 164 ] from the total ∆ v budget of 93 m/s . [ 165 ] : 10 Two sets of thrusters constitute the observatory's propulsion system. [ 166 ] Because the thrusters are located solely on the Sun-facing side of the observatory, all station-keeping operations are designed to slightly undershoot the required amount of thrust in order to avoid pushing Webb beyond the semi-stable L 2 point, a situation which would be unrecoverable. Randy Kimble, the Integration and Test Project Scientist for the JWST, compared the precise station-keeping of Webb to " Sisyphus [...] rolling this rock up the gentle slope near the top of the hill – we never want it to roll over the crest and get away from him". [ 167 ]
Webb is the formal successor to the Hubble Space Telescope (HST), and since its primary emphasis is on infrared astronomy , it is also a successor to the Spitzer Space Telescope . Webb will far surpass both those telescopes, being able to see many more and much older stars and galaxies. [ 168 ] Observing in the infrared spectrum is a key technique for achieving this, because of cosmological redshift , and because it better penetrates obscuring dust and gas. This allows observation of dimmer, cooler objects. Since water vapor and carbon dioxide in the Earth's atmosphere strongly absorbs most infrared, ground-based infrared astronomy is limited to narrow wavelength ranges where the atmosphere absorbs less strongly. Additionally, the atmosphere itself radiates in the infrared spectrum, often overwhelming light from the object being observed. This makes a space telescope preferable for infrared observation. [ 169 ]
The more distant an object is, the younger it appears; its light has taken longer to reach human observers. Because the universe is expanding , as the light travels it becomes red-shifted, and objects at extreme distances are therefore easier to see if viewed in the infrared. [ 170 ] Webb's infrared capabilities are expected to let it see back in time to the first galaxies forming just a few hundred million years after the Big Bang. [ 171 ]
Infrared radiation can pass more freely through regions of cosmic dust that scatter visible light. Observations in infrared allow the study of objects and regions of space which would be obscured by gas and dust in the visible spectrum , [ 170 ] such as the molecular clouds where stars are born, the circumstellar disks that give rise to planets, and the cores of active galaxies . [ 170 ]
Relatively cool objects (temperatures less than several thousand degrees) emit their radiation primarily in the infrared, as described by Planck's law . As a result, most objects that are cooler than stars are better studied in the infrared. [ 170 ] This includes the clouds of the interstellar medium , brown dwarfs , planets both in our own and other solar systems, comets , and Kuiper belt objects that will be observed with the Mid-Infrared Instrument (MIRI). [ 48 ] [ 171 ]
Some of the missions in infrared astronomy that impacted Webb development were Spitzer and the Wilkinson Microwave Anisotropy Probe (WMAP). [ 172 ] Spitzer showed the importance of mid-infrared, which is helpful for tasks such as observing dust disks around stars. [ 172 ] Also, the WMAP probe showed the universe was "lit up" at redshift 17, further underscoring the importance of the mid-infrared. [ 172 ] Both these missions were launched in the early 2000s, in time to influence Webb development. [ 172 ]
The Space Telescope Science Institute (STScI), in Baltimore, Maryland , on the Homewood Campus of Johns Hopkins University , was selected in 2003 as the Science and Operations Center (S&OC) for Webb with an initial budget of US$162.2 million intended to support operations through the first year after launch. [ 173 ] In this capacity, STScI was to be responsible for the scientific operation of the telescope and delivery of data products to the astronomical community. Data was to be transmitted from Webb to the ground via the NASA Deep Space Network , processed and calibrated at STScI, and then distributed online to astronomers worldwide. Similar to how Hubble is operated, anyone, anywhere in the world, will be allowed to submit proposals for observations. Each year several committees of astronomers will peer review the submitted proposals to select the projects to observe in the coming year. The authors of the chosen proposals will typically have one year of private access to the new observations, after which the data will become publicly available for download by anyone from the online archive at STScI. [ citation needed ]
The bandwidth and digital throughput of the satellite is designed to operate at 458 gigabits of data per day for the length of the mission (equivalent to a sustained rate of 5.42 Mbps ). [ 39 ] Most of the data processing on the telescope is done by conventional single-board computers. [ 174 ] The digitization of the analog data from the instruments is performed by the custom SIDECAR ASIC (System for Image Digitization, Enhancement, Control And Retrieval Application Specific Integrated Circuit ). NASA stated that the SIDECAR ASIC will include all the functions of a 9.1 kg (20 lb) instrument box in a 3 cm (1.2 in) package and consume only 11 milliwatts of power. [ 175 ] Since this conversion must be done close to the detectors, on the cold side of the telescope, the low power dissipation is crucial for maintaining the low temperature required for optimal operation of Webb. [ 175 ]
The telescope is equipped with a solid-state drive (SSD) with a capacity of 68 GB, used as temporary storage for data collected from its scientific instruments. By the end of the 10-year mission, the usable capacity of the drive is expected to decrease to 60 GB due to the effects of radiation and read/write operations. [ 176 ]
The C3 [ c ] mirror segment suffered a micrometeoroid strike from a large dust mote-sized particle between 23 and 25 May 2022, the fifth and largest strike since launch, reported 8 June 2022, which required engineers to compensate for the strike using a mirror actuator . [ 178 ] Despite the strike, a NASA characterization report states "all JWST observing modes have been reviewed and confirmed to be ready for science use" as of 10 July 2022. [ 179 ] Micrometeoroids strike Webb an average of once or twice per month, and only the May 2022 strike caused noticeable damage. [ 180 ] After that strike, mission personnel implemented a strategy to change Webb's observations to reduce the risk of further damage. The strategy is to avoid pointing the mirror toward "micrometeoroid avoidance zones" at particular points along Webb's orbit. [ 181 ]
The launch (designated Ariane flight VA256 ) took place as scheduled at 12:20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana . [ 182 ] [ 183 ] The telescope was confirmed to be receiving power, starting a two-week deployment phase of its parts [ 184 ] and traveling to its target destination. [ 185 ] [ 186 ] [ 187 ] The telescope was released from the upper stage 27 minutes 7 seconds after launch, beginning a 30-day adjustment to place the telescope in a Lissajous orbit [ 188 ] around the L2 Lagrange point .
The telescope was launched with slightly less speed than needed to reach its final orbit, and slowed down as it travelled away from Earth, in order to reach L 2 with only the velocity needed to enter its orbit there. The telescope reached L 2 on 24 January 2022. The flight included three planned course corrections to adjust its speed and direction. This is because the observatory could recover from underthrust (going too slowly), but could not recover from overthrust (going too fast) – to protect highly temperature-sensitive instruments, the sunshield must remain between telescope and Sun, so the spacecraft could not turn around or use its thrusters to slow down. [ 189 ]
An L 2 orbit is unstable , so JWST needs to use propellant to maintain its halo orbit around L2 (known as station-keeping ) to prevent the telescope from drifting away from its orbital position. [ 190 ] It was designed to carry enough propellant for 10 years, [ 191 ] but the precision of the Ariane 5 launch and the first midcourse correction were credited with saving enough onboard fuel that JWST may be able to maintain its orbit for around 20 years instead. [ 192 ] [ 193 ] [ 194 ] Space.com called the launch "flawless". [ 195 ]
Webb was released from the rocket upper stage 27 minutes after a flawless launch. [ 182 ] [ 195 ] Starting 31 minutes after launch, and continuing for about 13 days, Webb began the process of deploying its solar array, antenna, sunshield, and mirrors. [ 197 ] Nearly all deployment actions are commanded by the Space Telescope Science Institute in Baltimore , Maryland, except for two early automatic steps, solar panel unfolding and communication antenna deployment. [ 198 ] [ 199 ] The mission was designed to give ground controllers flexibility to change or modify the deployment sequence in case of problems. [ 200 ]
At 7:50 p.m. EST on 25 December 2021, about 12 hours after launch, the telescope's pair of primary rockets began firing for 65 minutes to make the first of three planned mid-course corrections. [ 201 ] On day two, the high gain communication antenna deployed automatically. [ 200 ]
On 27 December 2021, at 60 hours after launch, Webb's rockets fired for nine minutes and 27 seconds to make the second of three mid-course corrections for the telescope to arrive at its L 2 destination. [ 202 ] On 28 December 2021, three days after launch, mission controllers began the multi-day deployment of Webb's all-important sunshield. On 30 December 2021, controllers successfully completed two more steps in unpacking the observatory. First, commands deployed the aft "momentum flap", a device that provides balance against solar pressure on the sunshield, saving fuel by reducing the need for thruster firing to maintain Webb's orientation. [ 203 ]
On 31 December 2021, the ground team extended the two telescoping "mid booms" from the left and right sides of the observatory. [ 204 ] The left side deployed in 3 hours and 19 minutes; the right side took 3 hours and 42 minutes. [ 205 ] [ 204 ] Commands to separate and tension the membranes followed between 3 and 4 January and were successful. [ 204 ] On 5 January 2022, mission control successfully deployed the telescope's secondary mirror, which locked itself into place to a tolerance of about one and a half millimeters. [ 206 ]
The last step of structural deployment was to unfold the wings of the primary mirror. Each panel consists of three primary mirror segments and had to be folded to allow the space telescope to be installed in the fairing of the Ariane rocket for the launch of the telescope. On 7 January 2022, NASA deployed and locked in place the port-side wing, [ 207 ] and on 8 January, the starboard-side mirror wing. This successfully completed the structural deployment of the observatory. [ 208 ] [ 209 ] [ 210 ]
On 24 January 2022, at 2:00 p.m. Eastern Standard Time, [ 211 ] nearly a month after launch, a third and final course correction took place, inserting Webb into its planned halo orbit around the Sun–Earth L 2 point. [ 212 ] [ 213 ]
The MIRI instrument has four observing modes – imaging, low-resolution spectroscopy, medium-resolution spectroscopy and coronagraphic imaging. "On Aug. 24, a mechanism that supports medium-resolution spectroscopy (MRS), exhibited what appears to be increased friction during setup for a science observation. This mechanism is a grating wheel that allows scientists to select between short, medium, and longer wavelengths when making observations using the MRS mode," said NASA in a press statement. [ 214 ]
On 12 January 2022, while still in transit, mirror alignment began. The primary mirror segments and secondary mirror were moved away from their protective launch positions. This took about 10 days, because the 132 [ 215 ] actuator motors are designed to fine-tune the mirror positions at microscopic accuracy (10 nanometer increments) and must each move over 1.2 million increments (12.5 mm) during initial alignment. [ 216 ] [ 40 ]
Mirror alignment requires each of the 18 mirror segments, and the secondary mirror, to be positioned to within 50 nanometers. NASA compares the required accuracy by analogy: "If the Webb primary mirror were the size of the United States, each [mirror] segment would be the size of Texas, and the team would need to line the height of those Texas-sized segments up with each other to an accuracy of about 1.5 inches". [ 217 ]
Mirror alignment was a complex operation split into seven phases, that had been repeatedly rehearsed using a 1:6 scale model of the telescope. [ 217 ] Once the mirrors reached 120 K (−153 °C; −244 °F), [ 218 ] NIRCam targeted the 7th-magnitude star HD 84406 in Ursa Major . [ d ] [ 220 ] [ 221 ] To do this, NIRCam took 1560 images of the sky and used these wide-ranging images to determine where in the sky each segment of the main mirror initially pointed. [ 222 ] At first, the individual primary mirror segments were greatly misaligned, so the image contained 18 separate, blurry, images of the star field, each containing an image of the target star. The 18 images of HD 84406 are matched to their respective mirror segments, and the 18 segments are brought into approximate alignment centered on the star ("Segment Image Identification"). Each segment was then individually corrected of its major focusing errors, using a technique called phase retrieval , resulting in 18 separate good quality images from the 18 mirror segments ("Segment Alignment"). The 18 images from each segment, were then moved so they precisely overlap to create a single image ("Image Stacking"). [ 217 ]
With the mirrors positioned for almost correct images, they had to be fine tuned to their operational accuracy of 50 nanometers, less than one wavelength of the light that will be detected. A technique called dispersed fringe sensing was used to compare images from 20 pairings of mirrors, allowing most of the errors to be corrected ("Coarse Phasing"), and then introduced light defocus to each segment's image, allowing detection and correction of almost all remaining errors ("Fine Phasing"). These two processes were repeated three times, and Fine Phasing will be routinely checked throughout the telescope's operation. After three rounds of Coarse and Fine Phasing, the telescope was well aligned at one place in the NIRCam field of view. Measurements will be made at various points in the captured image, across all instruments, and corrections calculated from the detected variations in intensity, giving a well-aligned outcome across all instruments ("Telescope Alignment Over Instrument Fields of View"). Finally, a last round of Fine Phasing and checks of image quality on all instruments was performed, to ensure that any small residual errors remaining from the previous steps, were corrected ("Iterate Alignment for Final Correction"). The telescope's mirror segments were then aligned and able to capture precise focused images. [ 217 ]
In preparation for alignment, NASA announced at 19:28 UTC on 3 February 2022, that NIRCam had detected the telescope's first photons (although not yet complete images). [ 217 ] [ 223 ] On 11 February 2022, NASA announced the telescope had almost completed phase 1 of alignment, with every segment of its primary mirror having located and imaged the target star HD 84406, and all segments brought into approximate alignment. [ 222 ] Phase 1 alignment was completed on 18 February 2022, [ 224 ] and a week later, phases 2 and 3 were also completed. [ 225 ] This meant the 18 segments were working in unison, however until all 7 phases are complete, the segments were still acting as 18 smaller telescopes rather than one larger one. [ 225 ] At the same time as the primary mirror was being commissioned, hundreds of other instrument commissioning and calibration tasks were also ongoing. [ 226 ]
Webb observing time is allocated through a General Observers (GO) program, a Guaranteed Time Observations (GTO) program, a Director's Discretionary Early Release Science (DD-ERS) program, [ 231 ] a calibration program, and a Director's Discretionary Time (DDT) program. [ 232 ] The GTO program provides guaranteed observing time for scientists who developed hardware and software components for the observatory. The GO program provides all astronomers the opportunity to apply for observing time and will represent the bulk of the observing time. GO programs are selected through peer review by a Time Allocation Committee (TAC), similar to the proposal review process used for the Hubble Space Telescope. The DDT program is used for time-critical observations.
In November 2017, the Space Telescope Science Institute announced the selection of 13 Director's Discretionary Early Release Science (DD-ERS) programs, chosen through a competitive proposal process. [ 233 ] [ 234 ] The observations for these programs – Early Release Observations (ERO) [ 235 ] [ 236 ] – were to be obtained during the first five months of Webb science operations after the end of the commissioning period. A total of 460 hours of observing time was awarded to these 13 programs, which span science topics including the Solar System , exoplanets , stars and star formation , nearby and distant galaxies , gravitational lenses , and quasars . These 13 ERS programs were to use a total of 242.8 hours of observing time on the telescope (not including Webb observing overheads and slew time).
For GO Cycle 1 there were 6,000 hours of observation time available to allocate, and 1,173 proposals were submitted requesting a total of 24,500 hours of observation time. [ 250 ] Selection of Cycle 1 GO programs was announced on 30 March 2021, with 266 programs approved. These included 13 large programs and treasury programs producing data for public access. [ 251 ] The Cycle 2 GO program was announced on 10 May 2023. [ 252 ] Webb science observations are nominally scheduled in weekly increments. The observation plan for every week is published on Mondays by the Space Telescope Science Institute. [ 253 ] In Cycle 4 the telescope showed its continued popularity in the astronomy community by garnering 2,377 proposals for 78,000 hours of observing time, nine times more than the available amount. [ 254 ]
The JWST completed its commissioning and began full scientific operations on 11 July 2022. [ 255 ] With some exceptions, most experiment data is kept private for one year for the exclusive use of scientists running that particular experiment, and then the raw data is released to the public. [ 256 ]
JWST observations substantially advanced understanding of exoplanets, the first billion years of the universe, [ 263 ] and other astrophysical and cosmological phenomena.
The first full-color images and spectroscopic data were released on 12 July 2022, which also marked the official beginning of Webb's general science operations. U.S. President Joe Biden revealed the first image, Webb's First Deep Field , on 11 July 2022. [ 259 ] [ 260 ] Additional releases around this time include: [ 264 ] [ 265 ] [ 266 ]
On 14 July 2022, NASA presented images of Jupiter and related areas by the JWST, including infrared views. [ 269 ]
In a preprint released around the same time, NASA, ESA and CSA scientists stated that "the science performance of JWST is better than expected". The document stated that during the commissioning, the instruments captured spectra of transiting exoplanets with a precision better than 1000 ppm per data point, and tracked moving objects with speeds up to 67 milliarcseconds/second, more than twice as fast as the requirement. [ a ] It also obtained the spectra of hundreds of stars simultaneously in a dense field towards the Milky Way 's Galactic Center . Other targets included: [ 26 ]
Within two weeks of the first Webb images, several preprint papers described a wide range of high redshift and very luminous (presumably large) galaxies believed to date from 235 million years (z=16.7) to 280 million years after the Big Bang, far earlier than previously known. [ 235 ] [ 236 ] On 17 August 2022, NASA released a large mosaic image of 690 individual frames taken by the NIRCam on Webb of numerous very early galaxies. [ 271 ] [ 272 ] Some early galaxies observed by Webb like CEERS-93316 , which has an estimated redshift of approximately z=16.7 corresponding to 235.8 million years after the Big Bang, are high redshift galaxy candidates. [ 273 ] [ 274 ] In September 2022, primordial black holes were proposed as explaining these unexpectedly large and early galaxies. [ 275 ] [ 276 ] [ 277 ] In May 2024, the JWST identified the most distant known galaxy, JADES-GS-z14-0, [ 278 ] seen just 290 million years after the Big Bang, corresponding to a redshift of 14.32. Part of the JWST Advanced Deep Extragalactic Survey (JADES), this discovery highlights a galaxy significantly more luminous and massive than expected for such an early period. Detailed analysis using JWST's NIRSpec and MIRI instruments revealed this galaxy's remarkable properties, including its significant size and dust content, challenging current models of early galaxy formation. [ 278 ]
In June 2023, detection of organic molecules 12 billion light-years away in the SPT0418-47 galaxy was announced. [ 279 ]
On 12 July 2023, NASA celebrated the first year of operations with the release of Webb's image of a small star-forming region in the Rho Ophiuchi cloud complex , 390 light years away. [ 280 ]
In December 2023, NASA released Christmas holiday-related images by JWST, including the Christmas Tree Galaxy Cluster and others. [ 281 ]
In May 2024, the JWST detected the farthest known black hole merger. [ 282 ] Occurring within the galaxy system ZS7, 740 million years after the Big Bang, this discovery suggests a fast growth rate for black holes through mergers, even in the young Universe. [ original research? ] | https://en.wikipedia.org/wiki/James_Webb_Space_Telescope |
James William Peter Hirschfeld (born 1940) is an Australian mathematician, resident in the United Kingdom, specializing in combinatorial geometry and the geometry of finite fields . He is an emeritus professor and Tutorial Fellow at the University of Sussex .
Hirschfeld received his doctorate in 1966 from the University of Edinburgh with thesis advisor William Leonard Edge and thesis The geometry of cubic surfaces, and Grace's extension of the double-six, over finite fields . [ 1 ]
To pursue further studies in finite geometry Hirschfeld went to University of Perugia and University of Rome with support from the Royal Society and Accademia nazionale dei Lincei . He edited Beniamino Segre 's 100-page monograph "Introduction to Galois Geometries" (1967). [ 2 ]
In 1979 Hirschfeld published the first of a trilogy on Galois geometry , pegged at a level depending only on "the group theory and linear algebra taught in a first degree course, as well as a little projective geometry , and a very little algebraic geometry ." When q is a prime power then there is a finite field GF( q ) with q elements called a Galois field. A vector space over GF( q ) of n + 1 dimensions produces an n-dimensional Galois geometry PG( n,q ) with its subspaces: one-dimensional subspaces are the points of the Galois geometry and two-dimensional subspaces are the lines. Non-singular linear transformations of the vector space provide motions of PG( n,q ). The first book (1979) covered PG(1, q ) and PG(2, q ). The second book addressed PG(3, q ) and the third PG( n,q ). Chapters are numbered sequentially through the trilogy: 14 in the first book, 15 to 21 in the second, and 22 to 27 in the third. Finite geometry has contributed to coding theory , such as algebraic geometry codes , so the field is supported by computer science . In the preface of the 1991 text Hirschfeld summarizes the status of Galois geometry, mentioning maximum distance separable code , mathematics journals publishing finite geometry, and conferences on combinatorics featuring Galois geometry. Colleague Joseph A. Thas is coauthor of General Galois Geometries on PG( n,q ) where n ≥ 4.
Hirschfeld was cited as the ultimate editor of Design Theory (1986). [ 3 ]
In 2018 he received the 2016 Euler Medal . [ 4 ] | https://en.wikipedia.org/wiki/James_William_Peter_Hirschfeld |
The Jameson Cell is a high-intensity froth flotation cell that was invented by Laureate Professor Graeme Jameson of the University of Newcastle (Australia) and developed in conjunction with Mount Isa Mines Limited ("MIM", a subsidiary of MIM Holdings Limited and now part of the Glencore group of companies). [ 1 ]
The high intensity of the Jameson Cell means that it is much shorter than conventional column flotation cells (see Figure 1), and it does not require air compressors to aerate the suspension of ground ore particles and water (known as a slurry or pulp ) in the flotation cell. [ 2 ] The lack of a requirement for compressed air and the lack of moving parts means that power consumption is less than for the equivalent mechanical or conventional column flotation cell. [ 3 ]
In contrast to most types of flotation cell , the Cell introduces the feed and the air to the Cell in a combined stream via one or more cylindrical columns referred to as "downcomers". Other types of flotation cell typically introduce the feed and the air separately to the cell. [ 2 ]
The Cell produces fast mineral flotation rates, especially for very fine mineral particles. [ 3 ] It produces high concentrate grades from fast floating liberated particles [ 4 ] and is able to do this from a single stage of flotation. [ 4 ] The high carrying capacity of the Jameson Cell is particularly beneficial when high yields (mass pulls) are required, such as in recleaning in metals flotation and in the flotation of metallurgical coal , where yields can exceed 80%. [ 5 ]
The Cell was initially developed as a lower-cost alternative to conventional column flotation cells for recovering fine particles, and was first used in the Mount Isa lead–zinc concentrator in 1988. [ 6 ] Since then, use of the technology has spread to include coal flotation, base and precious metal flotation, potash flotation, oil sands flotation, molybdenum flotation, graphite flotation and cleaning solvent extraction liquors. [ 7 ] Xstrata Technology, Glencore Xstrata's technology marketing arm, listed 328 Jameson Cell installations in May 2013. [ 7 ] Cells have been installed by 94 companies in 27 countries. [ 7 ] Today, the technology is the standard in the Australian Coal Industry [ 8 ] where well over one hundred Cells have been installed to recover coal fines. [ 9 ] [ 10 ] It is mainly used in metals applications to solve final grade and capacity issues from conventional cell cleaner circuits. [ 5 ] It has found a niche in transforming traditional circuit designs where its inclusion allows cleaner circuits to be designed with fewer cells in a smaller footprint, while achieving cleaner and/or higher grade concentrates. [ 5 ] It has also made possible the recovery of previously discarded fine materials, such as coal [ 11 ] and phosphate fines, [ 12 ] thereby increasing the efficiency and extending the life of the world's non-renewable natural resources.
Froth flotation is achieved by mixing chemicals known as collectors with the ore slurry. The collectors adsorb onto the surfaces of the particles of select minerals (usually the valuable mineral that is targeted for concentration), making these minerals hydrophobic. Air is passed through the slurry in a tank known as a flotation cell. The air is broken into tiny bubbles by various mechanisms (depending on the design of the flotation cell), and the now-hydrophobic minerals attach to the bubbles, rising with them to the surface of the flotation cell, where they form a froth . The froth flows over the top edge (or "lip") of the flotation cell and forms the flotation concentrate. Ideally, none of the unwanted mineral particles float, and they remain behind as the flotation tailings .
However, the selectivity of the collection mechanism is not perfect. Some unwanted (" gangue ") minerals are also carried into the froth, largely by entrainment with the water rising with the bubbles. This is particularly the case for particles less than 10 μm in size. [ 13 ] Some of the gangue particles follow the water between the bubbles as it drains back to the underlying pulp. This process can be assisted by the application of sufficient "wash water" to the froth to displace the water entrained with the bubbles and the fine gangue particles brought with them. [ 2 ] Column flotation cells, invented in Canada by Boutin and Tremblay in 1961, [ 14 ] grew increasingly popular in the 1980s and 1990s as a way of reducing entrainment of fine gangue particles during "cleaning" of flotation concentrates. [ 13 ] [ 15 ] With heights usually between 6 and 14 meters, [ 16 ] they could have froth depths up to 2 m, [ 15 ] providing more residence time than conventional cells and more stable froth surfaces that enable better froth washing.
Froth flotation efficiency is determined by a series of probabilities: those of particle–bubble contact, particle–bubble attachment, transport between the pulp and the froth, and froth collection into the product launder. [ 17 ]
In a conventional mechanically agitated cell, the void fraction is low (5–10%) and the bubble size is large (2–3 mm), which results in a low interfacial area with a low probability of particle–bubble contact. [ 17 ] In a conventional flotation column, the void fraction is similarly low, and so the probability of particle–bubble contact is increased by increasing the height of the column to provide greater residence time. [ 17 ]
Traditionally, the ore slurry and the air are introduced separately to the flotation cell (see Figure 2). The Jameson Cell differs from this traditional approach by mixing the slurry with the air in the downcomers.
The slurry is introduced at the top of the downcomer as a jet that draws in air through a second pipe to form a stable two-phase mixture (see Figure 3). [ 1 ] The plunging slurry jet shears and then entrains the air. [ 18 ] The target minerals, with their collector-coated surfaces, attach to the bubbles and this mixture travels down the downcomer, driven by hydrostatic forces, [ 19 ] before it is discharged into the tank portion of the Jameson Cell (see Figure 4). [ 1 ] The downcomer is designed to provide high-intensity mixing of the air and the slurry to generate a dense foam of fine bubbles and maximise the contact between the target mineral particles and the bubbles. [ 20 ] The probability of particle–bubble contact is "virtually 100%" with a slurry residence time in the downcomer of 5–10 seconds. [ 17 ]
The high probability of particle–bubble contact, and subsequent short residence times (five to ten seconds in the downcomer, [ 17 ] allows for a much more compact column design than conventional column flotation cells (see Figure 1). [ 2 ] The fine nature of the bubbles (0.3 to 0.5 mm in diameter [ 4 ] ) gives them enhanced carrying capabilities for fine mineral particles. [ 2 ] Fine bubbles also improve the separation of minerals, as they intensify the difference in the flotation kinetics of the valuable minerals from the gangue minerals, thus allowing higher grade concentrates to be produced. [ 5 ]
The foam in the downcomer is about 50–60% air. [ 20 ] Because of this, the pulp is distributed in the form of thin interfacial slurry films between the bubbles, providing an ideal environment for particle–bubble contact. [ 17 ] Collection occurs by migration of the particles within the thin films, which are not much thicker than the diameter of the particles. [ 20 ]
The best collection occurs when the volume of air roughly equals that of the injected slurry. [ 20 ]
The Cell is operated by initially closing the air inlet at the top of the downcomer and feeding the flotation pulp in through the nozzle. [ 19 ] The air in the downcomer is entrained in the pulp, creating a partial vacuum that draws pulp from the tank up into the downcomer. [ 19 ] The pulp level quickly reaches the nozzle, which is at a level above that of the liquid level in the tank. [ 19 ] This creates a hydrostatic head in the downcomer, meaning that the pressure inside the top of the downcomer is lower than the atmospheric pressure. [ 19 ] When the inlet is opened, air is drawn into the top space of the downcomer by this lower pressure, where it too is entrained into the downcomer contents by the plunging jet. [ 19 ] At the same time, a downward flow is established in the pulp in the downcomer that is sufficient to counter the buoyancy of the bubbles, and the aerated pulp discharges into the tank. [ 19 ]
Once in the tank, the wider cross sectional area of the tank reduces the downward superficial velocity of the mixture, [ 19 ] allowing mineral-laden bubbles to disengage from the liquid [ 19 ] and rise to the surface as they would in a conventional cell, where they form the froth. [ 1 ] The velocity of the mixture discharging into the tank, and the large density differential between it and the remainder of the pulp in the tank, results in recirculating fluid patterns that keep the particles in the tank in suspension without requiring mechanical agitation. [ 18 ]
The purpose of the tank is simply for bubble–pulp separation, so the volume of the tank is small compared with alternative technologies. [ 4 ]
The froth that forms at the top of the tank flows over its lip to be collected. This froth can be "washed" by a light flow of water, if desired. [ 6 ] The bubbles flowing over the lip of the cell are smaller in diameter than those that flow over the lip of conventional flotation columns. [ 3 ]
The non-floating tailings are discharged through a hole in the bottom of the tank. [ 2 ]
The Cell has no moving parts and no requirement for compressed air or sparging mechanisms. [ 21 ] This results in lower power consumption than the equivalent mechanical or column flotation cells. [ 4 ] Maintenance costs are also lower because the only wearing part is the slurry lens used to create the jet in the downcomer. [ 4 ]
The Jameson Cell grew out of a long-term research program aimed at improving the recovery of fine particles by flotation. The work started at Imperial College London , and continued when Jameson moved in 1978 to the University of Newcastle, NSW, Australia, where he is Laureate Professor (2015).
Jameson's research into flotation began when he was at Imperial College London, in 1969. A colleague, Dr J. A. Kitchener of the Royal School of Mines , pointed out that many of the new mineral deposits being found around the world required fine grinding to separate the valuable particles from the rock in which they were embedded, and the flotation technologies available at the time were relatively inefficient for recovering fine particles. Kitchener felt that improvements could best be achieved by an increased knowledge of the physics of flotation, rather than the chemistry of the reagents. Jameson had gained some expertise in the properties of bubbles and particles in suspensions whilst a PhD student at Cambridge. He began research into the fluid mechanics of the flotation process and set in train a series of experimental projects into the effect of particle diameter and bubble size on the flotation rate constant. Much of the research was conducted by honours students in chemical engineering. Jameson accepted the challenge of coming up with practical solutions to remedy the situation, if these could be identified.
Jameson's research showed that the kinetics of flotation of fine particles was a strong function of the bubble diameter [ 22 ] [ 23 ] and that the way to improve recoveries was to use small bubbles in the order of 300 microns (μm) in diameter. What was needed was a practical method of making such bubbles in large quantities, of the order of billions per second. The device needed to be simple to construct and operate, capable of running for long periods with minimal maintenance, and should be resistant to blockage by stray large particles in the feed. He began to look at the theory of bubble breakup in sheared flows, that is, in flow fields in which layers of liquid slide over each other. Lewis and Davidson [ 24 ] had recently published a theory to predict the maximum size of bubbles in a well-characterised flow environment. By balancing the forces acting on a bubble in a shearing flow, including the disruptive dynamic stresses from the liquid motion and the restoring force of surface tension , it was possible to predict the critical shear rate required to produce a bubble of given size. Jameson then looked for simple and practical ways of generating the required shear rates , and found inspiration in the kitchen sink. If a jet of water from a tap plunges into a basin full of water, a shear layer develops around the jet, that entrains air from the atmosphere into the water, and at the same time, breaks up the entrained air into fine bubbles. The effect is magnified if there is a detergent in the water. Detergents, known as frothers, are used in flotation to prevent bubble coalescence, and to create stable froths. By the correct choice of jet velocity and diameter, it is possible to provide a controlled shear environment that can generate bubbles of a suitable size for flotation, with the added advantage that the air is naturally aspirated by the jet, so there is no need for a compressor or blower. Thus the idea of the Jameson Cell was born.
After a number of failures, the radical new process for flotation emerged in the laboratory at the University of Newcastle. Jameson filed a provisional patent application in 1986. After an initial trial at the Renison Bell tin mine in Tasmania, certain design features were modified. He led a further plant trial with a small cell in the lead-zinc concentrator at Mt Isa Mines Ltd in Queensland, initially working alone. The plant metallurgists took an interest in the technology and helped to refine it, particularly checking the scale-up procedures that Jameson had devised. In 1988 a recent graduate was assigned full-time for a year to verify and validate the performance of the Cell. In 1989 a worldwide exclusive license was negotiated between Tunra Ltd on behalf of the University of Newcastle, Jameson, and MIM Holdings Limited, for the use of the Cell for metallurgical purposes. Summary papers on the theory [ 25 ] and practice [ 19 ] have been published.
There have been ongoing significant changes to the design of the Cell since it was first developed in the late 1980s.
The commercial development of the Cell occurred indirectly as a result of problems being experienced in MIM's Mount Isa lead–zinc concentrator (sometimes referred to as a "mill" in the mining industry). MIM had been operating a lead–zinc concentrator at Mount Isa since 1931, [ 26 ] although lead–zinc ore was substituted with copper ore for a time between mid-1943 and mid-1946. [ 27 ] Over time, the lead, zinc and other mineral grains in the ore became progressively finer, the ore grade decreased and it became more difficult to treat. [ 28 ] These trends, combined with an increase in the concentrator's throughput, significantly reduced the concentrator's performance in the 1980s, resulting in a "tense" period of "an endless circle of circuit changes, reagent changes, operator changes, metallurgist changes, and so on". [ 28 ] The decreasing grain size and pushing the grinding circuit beyond its design throughput meant a reduction in the degree of separation of the individual mineral grains (referred to as "liberation") during grinding. From 1984 to 1991, the liberation of sphalerite (the zinc-bearing mineral, ZnS) decreased from almost 70% to just over 50%. [ 28 ] This decrease in liberation resulted in a reduction in the recovery of zinc to saleable zinc concentrate. [ 28 ]
The initial response to the problem of decreased zinc recovery was in 1986 to start to produce a lower-grade concentrate that was a mixture of zinc and lead (known in the industry as a "bulk concentrate" and referred to at Mount Isa as the "low-grade middlings concentrate"). [ 28 ] This concentrate typically contained 34% zinc and 13% lead, compared to the normal zinc concentrate composition of at least 50% zinc and less than 3% lead. [ 28 ]
By producing the bulk concentrate, the total recovery of zinc for sale was maintained at over 70% until 1989. [ 28 ] However, the high lead content meant that the bulk concentrate could not be treated by the electrolytic zinc process , and it had to be sold to zinc smelters using the more-expensive Imperial Smelting Process . Initially, MIM received good revenue from its bulk concentrate, but as the nature of the ore continued to deteriorate, the production of the bulk concentrate increased and saturated the market. Payment terms declined until MIM received less than half the payment for zinc in the bulk concentrate than it received for zinc in the zinc concentrate. [ 28 ]
The problems in the concentrator also affected the performance of MIM's Mount Isa lead smelter. [ 28 ] [ 29 ] The lead–zinc ore also contained increasing amounts of fine-grained, carbonaceous pyrite (FeS 2 ). [ 28 ] This material was naturally hydrophobic and floated without the aid of a collector into the lead concentrate, diluting it. The additional sulfur from the pyrite in the lead concentrate reduced the lead smelter's lead production because the ability to eliminate sulfur from the concentrate was lead smelter's capacity bottleneck. [ 28 ]
As part of the effort to try to fix the problems, MIM installed some column flotation cells in the zinc concentrate and bulk concentrate sections of the plant. [ 28 ] In those days, the air was introduced into flotation columns using air spargers , usually in the form of a bag or sheath around a pipe. [ 15 ] The spargers were high-maintenance items, and their performance was critical to the operation of the column. [ 15 ]
In 1985, MIM commissioned Jameson to undertake a project to improve the sparger design for flotation columns. [ 30 ] Instead, he developed the concept of using a jet in a downcomer to create the bubbles and eliminate the need for a sparger in conventional flotation columns. [ 30 ]
The concept of the Cell followed when further investigations showed that most of the bubble–particle interactions were occurring in the downcomer, rendering unnecessary the collection zone of flotation columns. [ 30 ] The idea of the downcomer and short separation tank was developed and a provisional patent application was lodged in 1986. [ 30 ] This patent was later assigned to TUNRA Limited ("TUNRA"), [ 30 ] the technology transfer company of the University of Newcastle that is now known as "Newcastle Innovation". [ 31 ] [ 32 ]
A pilot two tonne per hour (t/h) Jameson Cell with a 100 mm downcomer and using an orifice plate to create the jet was tested in MIM's lead–zinc concentrator. [ 30 ] Subsequently, in 1988, MIM tested the flotation of a stream of fine lead-bearing particles in a conventional mechanical flotation cell, a conventional column and the Jameson Cell. [ 30 ] The Cell gave the best recoveries. [ 30 ] This was thought to be a combination of the short residence time of the particles in the Cell and the fact that the hydrophobicity of the lead particles decreased over time. [ 30 ]
As a result of this work, in 1989 MIM ordered four full-scale Cells, two for the Mount Isa lead–zinc concentrator and another two for the new Hilton lead–zinc concentrator [ 30 ] to be built at the Hilton Mine, located about 20 kilometers north of Mount Isa. [ 33 ] The Mount Isa cells had diameters of 1.9 m, [ 34 ] with three downcomers each, [ 7 ] while those at Hilton were 1.3 m in diameter [ 33 ] and had two downcomers each. [ 7 ]
In parallel with this work, the Cell was tested for the recovery of fine coal at the Newlands coal mine , also owned by MIM Holdings Limited. [ 30 ] This fines stream was cyclone overflow , which contained 15–50% ash and was previously discarded. [ 10 ] The particle size of this stream was less than 25 μm. [ 10 ] Pilot plant testing showed that it was possible to achieve greater than 90% recovery of coal, with less than 10% ash in the product. [ 10 ]
Subsequently, a full-scale plant was commissioned at Newlands in the 1988–89 financial year, with six rectangular Cells (1.5 m × 3.5 m) installed in a two-stage arrangement. [ 30 ] The cells in the first stage had seven downcomers, while those in the second had six. [ 30 ] These cells were in continuous operation at Newlands for 15 years until a new washing plant was built to replace the old one in 2006. [ 10 ]
Two additional Cells were installed at MIM Holdings' Collinsville Coal operations in 1990. These had 10 downcomers each. [ 7 ]
Also in 1989, Peko Mines, then a division of North Broken Hill Peko Limited , also engaged Jameson to undertake test work in its Warrego concentrator near Tennant Creek in Australia's Northern Territory . [ 1 ] The objective was to determine the Jameson Cell's performance in cleaning copper concentrate to improve its grade by removing gangue minerals, including pyrite, magnetite , hematite and quartz . [ 1 ] Peko Mines personnel also tested a conventional flotation column for comparison. Following the test work, Peko Mines installed two full-scale, 1.4 m diameter Jameson Cells in the concentrator, each with three downcomers. [ 1 ]
Peko Mines' decision was based on:
Peko Mines reported a payback on the investment in the Cells of two months. [ 1 ]
Solvent extraction – electrowinning (often referred to as "SX–EW") is a process frequently applied for recovering copper from low-grade and/or oxidised copper ore. It involves leaching the copper from the ore using an acidic solution, collecting the leach liquor containing the copper and contacting this solution with an organic extractant. The copper ions in the leach liquor transfer to the organic extractant, moving from a relatively low concentration to a higher concentration. The extractant is subsequently brought into contact with a second aqueous solution that is more acid than the original leach liquor, and the copper again moves, this time from the extractant into the aqueous solution. The result is an acidic solution of copper in which the copper concentration is high enough for it to be recovered by electrowinning. The solution destined for electrowinning is known as the electrolyte . [ 35 ]
The electrolyte solution usually contains traces of the organic extractant that exist as tiny droplets within it. [ 36 ] These need to be removed before the copper can be recovered in the electrowinning process, as the presence of minimal amounts of the extractant can cause difficulties by stripping and damaging the cathodes with a subsequent loss of cathode copper quality. [ 37 ]
In the late 1980s, MIM built an SX–EW plant at Mount Isa to recover copper leached from low grade ore stockpiled while mining its Black Rock open cut in the 1960s. [ 36 ] In a world first, a Jameson Cell was used to clean the electrolyte solution by removing the remaining organic solvent. [ 36 ] This replaced the sand filters traditionally used. [ 6 ]
The cell was 3 m high, twice the height of the early Cells used in MIM's lead–zinc concentrators, as it was thought that additional residence time would enhance recovery. [ 6 ] It used a single downcomer. [ 7 ] The downcomer was used to contact the electrolyte with air and the droplets of the organic extractant attached themselves to the air bubbles created in the downcomer. [ 36 ]
After some initial modifications to the orifice size, the Cell was able to remove 70–90% of the entrained organic extractant. [ 6 ]
In April 1989, MIM Holdings Limited acquired the world rights to the Jameson Cell from TUNRA, with TUNRA retaining the rights to use the Cell for waste water treatment. [ 30 ]
After the initial applications within the MIM Holdings group of companies, the years to 1994 saw Jameson Cells installed by various base and precious metals companies in Asia, South Africa, Canada and the United States, mainly in concentrate cleaning duties, but also in SX–EW electrolyte cleaning duties. [ 7 ] The installation by Phelps Dodge (now Freeport-McMoRan ) for electrolyte cleaning at its Morenci operation in Arizona was notable for having a large cell 6.5 m in diameter with 30 downcomers. [ 7 ] The Morenci Jameson Cell consistently recovered over 82% of the organic extractant. [ 6 ]
Toward the end of the period, Cells were installed in coal preparation plants operated by the BHP Mitsubishi Alliance and by Peabody for fines recovery. [ 7 ]
Improvements to this early design included a focus on the weight and wear of the downcomer. [ 30 ] The downcomer was originally built with polyurethane -lined steel, and then changed to a high-density polyethylene ("HDPE") construction with seven elements. [ 30 ]
The orifice plate used to generate the slurry jet was a high-wear item and its materials of construction were also a focus of the development effort. [ 30 ] After testing high-chromium hardened steel and various ceramics, high-density alumina was found to have excellent wear properties, and it became the standard. [ 30 ]
The original Jameson Cell design had the following features:
In 1994 MIM launched the Mark II model Cell. [ 10 ] It incorporated the following changes:
These changes resulted in a higher capacity design. [ 10 ]
One of the problems encountered with the Mark I Cell was that its performance was reduced if the feed rate to the cell varied, which was a common occurrence arising from normal fluctuations in operating concentrators. [ 3 ] This problem was resolved by recycling some of the tailings to the cell feed via an external splitter box called an "External Recycle Mechanism" or "ERM" box separate to the flotation cell. [ 3 ] Thus, when the production of the feed stream to the Jameson Cell decreased as a result of a fluctuation elsewhere in the concentrator, a higher percentage of the tailings was automatically recycled to the downcomers, producing a constant flow rate, hence feed pressure, to the cell. [ 3 ] This had the added benefit of giving a proportion of the tailings (typically 40%) a second pass through the system, which resulted in higher recoveries. [ 3 ] In coal fines flotation, this allowed a single Cell to achieve the same recovery of combustibles as had previously been achieved in some two-stage Cell systems. [ 10 ]
Subsequently, an internal recycling system, referred to as the "internal recycle control" or "IRC" was developed. This was mainly used in integrated rectangular cells (see Figure 6), where the feed tank and tailings recycling system could easily be built in a single unit with the flotation cell. This system reduced the cell installation costs and made the cell more compact. [ 3 ]
During this period, the orifice diameter was increased from the 28 mm design used in 1990 to 34 mm with the Mark II model and 38 mm in 1997. [ 30 ] This, together with the larger Mark II downcomer diameter, allowed the slurry flow per downcomer to be doubled from 30 m 3 /h in 1990 to 60 m 3 /h in 1997. [ 30 ]
The increased distance between the downcomers reduced the interaction of aerated slurry discharging from adjacent downcomers. [ 30 ] This interaction could reduce overall cell recovery by causing particles collected by bubbles in the downcomer to detach in the pulp tank. [ 30 ]
There was significant turbulence in the areas beneath the downcomers. [ 30 ] that could result in particles detaching from bubbles. [ 30 ] These turbulent areas were calmed by the addition of conical diffusers beneath each downcomer. [ 30 ] They allowed uniform bubble rise velocities across the surface of the cell by slowing the superficial gas velocity in the high void-fraction area immediately around the downcomer and provided a more even bubble dispersion. [ 30 ] It was reported that the diffusers reduced the turbulence by 69% compared with a standard downcomer with no diffuser. [ 30 ]
While the JamesonCell continued to expand in base metals concentrate cleaning, SX–EW electrolyte cleaning and coal fines recovery applications, it also found new applications in cleaning potash slimes [ 38 ] and was adopted by the Philex Mining Corporation as the sole flotation machine for its Benguet copper concentrator. [ 39 ] This is not the normal application for the Cell. No other metals concentrator operates solely using Jameson Cells. [ 7 ]
Cleveland Potash Limited extracts and refines sylvinite ore from a deposit in North Yorkshire, England. [ 38 ] Its processing plant uses froth flotation to produce a product rich in potassium chloride ("KCl"). [ 38 ] After a test work campaign in which it compared the performance of the Cell with mechanical flotation cells in various duties in the flotation circuit, Cleveland Potash ordered a Cell with 6 downcomers for recovering potash slimes. [ 7 ] The test work had shown a 4.8% increase in the recovery of potash slimes, equivalent at the time to an increase in revenue of approximately £518,000 per year. [ 38 ]
In 1993 Philex Mining Corporation, a Philippines mining company, replaced the mechanical cleaner circuit with Cells at its Benguet copper concentrator. [ 39 ] Following their successful operation, Philex replaced the mechanical cells in its cleaner-scavenger circuit in 1994 and began the phased introduction of Cell rougher and scavenger lines that was completed in early 1996. [ 39 ] This was the first operation in which the external recycle mechanism system was applied. [ 3 ] By the time the last Jameson Cell was installed, the entire flotation circuit was composed of Jameson Cells. [ 39 ]
The motivation for installing Jameson Cells was, in part, to take advantage of their space-saving capabilities and to improve copper recovery at a minimum cost. [ 39 ] The Cell circuit occupied 60% less floor area and achieved equivalent results to the mechanical banks with 40% of their residence time. [ 39 ] They provided a power saving of 18%. [ 39 ]
In addition to these benefits, the use of the Jameson Cells in the rougher and rougher–scavenger section of the plant resulted in a 3.3% increase in copper recovery and a 4.5% increase in gold recovery. [ 39 ] When combined with the other Cells in the cleaner, recleaner and cleaner–scavenger section, there was a 2.6% increase in final copper concentrate grade and a 3.5% increase in plant copper recovery, with a 2.6% increase in plant gold recovery. [ 39 ]
The Mark III design encompassed the greatest improvement in the technology since its commercialisation. The focus was to make the technology more robust and easier to use in operations. The total redesign of the downcomer assembly allowed it to be isolated and unblocked much more easily compared to the Mark II design. The Mark III design also saw slurry flow per downcomer to be increased from 60 m 3 /h to 75–85 m 3 /h using larger orifice sizes in the slurry lenses. [ 40 ]
The Mark III Cell was introduced in 2000. It included the following improvements:
The earlier models of the Jameson Cell used orifice plates to generate the downcomer jet. [ 3 ] The new slurry lens design had a smooth, shallow entry angle that created an optimum flow regime over the ceramic, reducing wear and extending its life. [ 30 ] The shape resulted in a decrease in power consumption by the feed slurry pump by up to 10% and resulted in better jet formation that improved air entrainment. [ 30 ]
For coal applications, the wash water addition system was changed from a tray to stainless-steel circular rings attached to a manual lifting system. [ 30 ] This allowed the flexibility of an easy transition from above-froth wash water addition to the in-froth addition that might be necessary for high concentrate-grade operations. [ 30 ] For metals applications, new design wash water trays consisting of removable rubber mats for easy maintenance were used. [ 40 ]
The AISE valves were developed to prevent solids being sucked back into the air lines when individual downcomers become blocked. Solids depositing in the air lines and their build up in the air distributor decreases flotation performance as it prevents air from being efficiently entrained in the downcomers. [ 30 ]
This period was one of rapid growth for the Jameson Cells in the existing applications. [ 7 ] Seventy-seven Cells were installed in concentrators around the world, mainly in coal and base metal operations. [ 7 ] However, during this time, the Cell also moved into the Canadian oil sands industry for the flotation of bitumen. [ 7 ]
Flotation is one of the unit processes used to separate the bituminous component of oil sands as part of the process of oil extraction. [ 41 ] Some of the bitumen is not recovered in the primary separation vessel and reports to the tailings. [ 41 ] These tailings are typically retreated in a scavenging operation to try to recover some of the remaining bitumen. [ 41 ]
Three industrial-size single downcomer Jameson Cells were sold by Xstrata Technology to Shell Canada in 2007 for a large scale pilot plant project and eight 500 mm downcomers were sold to Syncrude Limited in 2008. [ 7 ] In the latter case, the downcomers were used to treat middlings in an existing tertiary oil recovery vessel in a bitumen recovery process patented by Syncrude. [ 41 ]
The Mark IV Cell design was introduced in 2009. It included the following improvements:
In base and precious metals flotation, the Jameson Cell has established itself as being particularly useful in several applications in flotation circuits that also use other types of flotation cells, such as mechanical cells. These applications include:
The Jameson Cell has been found to be particularly effective in cleaning and recovering fine coal particles. For example, at BHP Coal's Goonyella mine (now part of the BHP Mitsubishi Alliance) eight Cells were installed to replace the entire 32 mechanical cell flotation circuit in 1995 in its 1800 t/h coal flotation plant. [ 10 ] [ 21 ] The result was an overall increase in yield for the plant of 3.5% (better than the predicted yield of 2.1% that was used to justify the project) and the production of a low-ash product. [ 21 ]
Since then, Jameson Cells have been installed in many coal preparation plants around the world, [ 7 ] with the largest installation at the Curragh coal mine in Australia, where 12 Cells treat over 5 million t/y of coal fines. [ 42 ]
The Cell can also be applied to coal preparation plant tailings to recover fine coal previously discarded.
The Jameson Cell is used to recover the organic solvent in solvent extraction – electrowinning plants from both the electrolyte and raffinate streams. [ 42 ]
Contamination of the electrolyte increases operating costs and reduces the quality of the copper product. [ 42 ] Any solvent remaining in the raffinate stream represents a loss of solvent and hence an increase in operating costs. [ 42 ]
Major users of the Cell in SX–EW plants include Freeport McMoRan at its Morenci operations, BHP Billiton at its Olympic Dam operations and Grupo México at its Cananea and La Caridad operations. [ 7 ] In all, Xstrata Technology reports 41 SX–EW applications. [ 7 ]
Recent developments in the Cell design for SX–EW applications include large, flat-bottomed cell design to allow it to sit on the ground and large (500 mm diameter) downcomers that can have multiple liquor (there being no slurry in SX–EW applications) lenses fitted to each downcomer.
The biggest operating Cell is at the Olympic Dam operations, treating 3000 m 3 /h of raffinate. [ 42 ]
The first potash application was in England in 1993, where Jameson Cells were used to treat potash slimes (see Potash flotation ). [ 38 ] It has subsequently been applied at Israel Chemicals Limited's Dead Sea Works and by an unnamed producer in the Saskatchewan province of Canada. [ 7 ]
The Jameson Cell has been adopted by Shell Canada and Syncrude for floating bitumen in the oil sands industry (see Bitumen flotation ). [ 7 ] Syncrude bought an additional eight 500 mm downcomers for its plant in 2012. [ 7 ]
The Jameson Cell can be used for the reverse flotation of silica from iron ore, where flotation columns have traditionally been used. [ 40 ]
Phosphate processing operations that use flotation as the principal mechanism to concentrate the phosphate-bearing minerals usually discard particles smaller than 20 μm in diameter. [ 12 ] This is because the fine particles have had poor flotation performance and because their presence decreases the flotation performance of the coarse particles. [ 12 ]
Legend International Holdings Incorporated ("Legend") owns major phosphate deposits that average 20–60% particles less than 20 μm that contain up to 50% of the phosphate. [ 12 ] This makes the traditional phosphate concentration practice uneconomic for these deposits. [ 12 ] In response, Legend developed a process based on using the Jameson Cell in a rougher-scavenger-cleaner configuration to recover at least 80% of the phosphate at a grade of at least 32% P 2> O 5 from a feed with a particle size distribution of up to 80% less than 20 μm. [ 12 ]
The Jameson Cell reportedly has the following advantages: | https://en.wikipedia.org/wiki/Jameson_cell |
Jami al-tafsir , also spelled as Jame Tafasir, is a multimedia software produced by the Noor Computer Research Center of Islamic Sciences . It is a tafsir in the form of an encyclopedia of the Qur'an .
The Jame tafsir contains an exhibition of complete texts of 184 commentaries of different Islamic sects in 1225 volumes such as: Min Wahy al-Qur`an, al-Tebyan Fi Tasfir al-Qur`an , Noor al-Thaqalain , Kashful Asrar wa Edatol Abrar , Tafsir al-Qur`an al-Karim , al-Amthal Fi Tafsir al-Ketab al-Munzal, al-Mizan Fi Tafsir al-Qur`an from Muhammad Husayn Tabatabaei , Tafsir Nemouneh , Majma’ al-Bayan Fi Tafsir al-Qur`an , Tafsir Rawdh al-Jinan and Tafsir Beidhawi. [ 1 ]
The aim of the software is to provide content and options to simplify the research path for researchers of Islamic sciences and Qur'anic scholars.
This Islam-related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jami_al-tafsir |
Jamming is the physical process by which the viscosity of some mesoscopic materials, such as granular materials , glasses , foams , polymers , emulsions , and other complex fluids , increases with increasing particle density. The jamming transition has been proposed as a new type of phase transition , with similarities to a glass transition but very different from the formation of crystalline solids . [ 1 ]
While a glass transition occurs when the liquid state is cooled, the jamming transition happens when the density, or the packing fraction of the particles, is increased. This crowding of the constituent particles prevents them from flowing under an applied stress and from exploring phase space , thus making the aggregate material behave as a solid. The system may be able to unjam if volume fraction is decreased, or external stresses are applied such that they exceed the yield stress. This transition is interesting because it is nonlinear with respect to volume fraction.
The jamming phase diagram relates the jamming transition to inverse density, stress
and temperature. [ 2 ]
The density at which systems jam is determined by many factors, including the shape of their components, the deformability of the particles, frictional interparticle forces, and the degree of dispersity of the system. The overall shape of the jamming manifold may depend on the particular system. For example, a particularly interesting feature of the jamming transition is the difference between attractive and repulsive particle systems. Whether the jamming surface diverges for high enough densities or low temperatures is uncertain.
Simulations of jammed systems study particle configurations leading to jamming in both static systems and systems under shear. Under shear stress , the average cluster size may diverge after a finite amount of strain, leading to a jammed state. A particle configuration may exist in a jammed state with a stress required to "break" the force chains causing the jam.
The simplest realization of a static jammed system is a random sphere packing of frictionless soft spheres that are jammed together upon applying an external hydrostatic pressure to the packing. Right at the jamming transition, the applied pressure is zero and the shear modulus is also zero, which coincides with the loss of rigidity and the unjamming of the system. Also, at the jamming point the system is isostatic. Above the jamming point, the applied pressure causes an increase of volume fraction by squeezing the soft spheres closer together, and thus creates additional contacts between neighboring spheres. This leads to an increase of the average number of contacts z {\displaystyle z} . As shown in numerical simulations by Corey O'Hern and collaborators, the shear modulus G increases with increasing z {\displaystyle z} following the law: G ∼ ( z − 2 d ) {\displaystyle G\sim (z-2d)} , where d is the dimension of space. [ 3 ] A first-principles microscopic theory of elasticity developed by Alessio Zaccone and E. Scossa-Romano quantitatively explains this law in terms of two contributions: the first term is a bonding-type contribution, thus proportional to z {\displaystyle z} , and related to particle displacements which exactly follow the applied shear deformation ; the second (negative) term is due to internal relaxations needed to keep local mechanical equilibrium in a strained disordered environment, and thus proportional to the total number of degrees of freedom, hence the dependence on space dimension d . [ 4 ] This model is relevant for compressed emulsions, where the friction between particles is negligible.
Another example of static jammed system is a sand pile, which is jammed under the force of gravity and no energy is being dissipated.
Systems which are consuming energy are also sometimes described as being jammed. An example is traffic jams , where due to jamming the average velocity of cars on a road may drop sharply. Here the cars on a road may be thought of like a granular material or a non-Newtonian fluid that is being pumped through a tube. There under certain conditions the effective viscosity may rapidly increase, dramatically increasing the granular material or fluids 's resistance to flowing and so causing the velocity to drop or even come to a complete stop. In this analogy the cars are like the grains in a granular material and if they are dense enough (i.e., closely enough spaced along the road) then interactions between the cars (as they must avoid each other to avoid crashing) cause jamming. A simple model of this behavior is the Nagel-Schreckenberg model .
The notion of jamming can also be considered from a biophysical perspective to characterize the arrest of cellular motion. [ 5 ] Cell motility is of importance in many biological processes including tissue morphogenesis, wound healing, and cancer invasion. [ 6 ] [ 7 ] Characterizing the mechanisms that result in these "jamming" and "unjamming" phenomena can yield a more nuanced view of tissue development and aid in identifying new targets for disease therapies. [ 5 ] [ 8 ] Identifying properties defining these cellular phase changes has been a topic of recent interest. Cell density-based jamming is analogous to particle jamming in physical science, as the viscosity of a group of cells, like a group of particles, will increase as cell density increases. Other key parameters uniquely discussed for cell jamming include cell shape, cell-cell contact, and cell motion, studied in both embryonic organization [ 9 ] and asthma. [ 10 ] These factors are closely related to each other. In one attempt to illustrate the mechanisms of cell jamming, Lawson-Keister et. al. use three factors: a) density, b) geometric incompatibility, and c) fluctuations. [ 5 ] Efforts of experimentally quantifying cellular viscoelastic phases include in-vivo injection of force-sensing ferrofluid , [ 11 ] micropipette aspiration, [ 12 ] and 3D digital image correlation of cellular displacement. [ 13 ] | https://en.wikipedia.org/wiki/Jamming_(physics) |
Jan-Erik Ingvar Roos (16 October 1935 – 15 December 2017) [ 1 ] was a Swedish mathematician whose research interests were in abelian category theory , homological algebra , and related areas.
He was born in Halmstad , in the province of Halland on the Swedish west coast. [ 2 ] Roos enrolled at Lund University in 1954, and started studying mathematics with Lars Gårding in 1957. [ 3 ] Under Gårding's direction he wrote a thesis on ordinary differential equation , and graduated in 1958 with a licentiate degree. [ 2 ] [ 4 ] Later that year he went to Paris on a doctoral scholarship; [ 3 ] there, he gravitated towards the mathematical environment at the Institut Henri Poincaré , and the various seminars held there. After a while, he started attending Alexander Grothendieck 's seminar at the Institut des hautes études scientifiques in Bures-sur-Yvette , where he became interested in abstract algebra and algebraic geometry . [ 5 ] In 1967 he was invited by Saunders Mac Lane to visit the University of Chicago for three months; Mac Lane was impressed by Roos and later wrote a very positive letter of recommendation for him. [ 3 ]
Upon his return to Sweden, Roos was appointed Professor of Mathematics at Stockholm University in 1970, and started building a strong algebra school. [ 2 ] He was elected to the Royal Swedish Academy of Sciences in 1980 and was its President from 1980 to 1982. [ 6 ] While serving on the Academy, he was on the committees deciding the Rolf Schock Prizes in Mathematics [ 7 ] and the Crafoord Prize in Astronomy and Mathematics. [ 8 ]
Roos made important contributions to homological algebra , and did extensive computer-assisted studies of Hilbert–Poincaré series and their rationality. [ 9 ] A special issue of the journal Homology, Homotopy and Applications ("The Roos Festschrift volume") was published in 2002, on the occasion of his 65th birthday. [ 10 ]
He died on 15 December 2017 at his home in Uppsala [ 2 ] and is buried at the Uppsala old cemetery . | https://en.wikipedia.org/wiki/Jan-Erik_Roos |
Jan C. A. Boeyens FRSSAf [ 1 ] (October 2, 1934 – August 26, 2015) was a South African chemist and educator.
Boeyens was educated at the University of Pretoria . He worked at the Council for Scientific and Industrial Research of South Africa and at Stanford University . He became a professor of chemistry at the University of the Witwatersrand and Extraordinary Professor at UNISA .
He has written or co-written more than 600 scientific contributions. Some of his books are used as textbooks of theoretical chemistry all over the world.
As an emeritus he wrote books challenging the current scientific consensus about the adequacy of quantum mechanics in which he presented a way to establish more accurate modern physics and chemistry without using higher mathematics by using elementary number theory .
Jan Boeyens was born 2 October 1934 in Wesselsbron, Free State, South Africa. He attended the University of the Orange Free State and in 1955 he obtained a BSc (Chemistry, Physics, Mathematics), in 1956 a BSc(Hons) (Chemistry) and in 1957 MSc ( Cum Laude ) (Chemistry). He was appointed lecturer in chemistry at the University of the Orange Free State from 1958 to 1960.
He was lecturer in Physical Chemistry at the University of South Africa (UNISA) and worked at the National Physical Laboratory of the Council for Scientific and Industrial Research (CSIR) where he was Chief Research officer and Head of Crystallography division: Physical Chemistry Group from 1961 to 1963.
He attended the University of Pretoria from 1963 to 1964 and obtained a DSc (with Honours) (Physical and Theoretical Chemistry). His postdoctoral studies were at Stanford University from 1965 to 1966 where he was a Research Associate: Physical Chemistry.
He worked at the National Institute for Metallurgy, MINTEK as Chief Scientist and Director of Mintek Research Group for Applied Structural Chemistry, Rand Afrikaans University from 1971 to 1973. He was appointed Honorary Lecturer at Rand Afrikaans University from 1973 to 1975. In 1976 he was a Visiting Researcher at the University of Sussex , England.
He returned to the National Physical Laboratory of the CSIR in 1976 where he worked as Head: Physical Chemistry (Structural Chemistry and X-ray Crystallography) until 1980.
He was appointed Professor of Theoretical Physics at the University of the Witwatersrand (WITS) from 1981 to 1999. He was also a visiting professor at Texas A&M University in 1984. Boeyens was appointed Head: Department of Chemistry at WITS from 1984 to 1990 and again from 1997 to 1999. From 1986 to 1999 he was the Director: Centre for Molecular Design at WITS and from 1991 to 1993 became the Dean: Faculty of Science. He was visiting professor at the Free University of Berlin in 1994, and at the University of Heidelberg , Germany in 1998, 2005, 2006, 2007 and 2010.
He lectured as professor of chemistry and was Head, Department of Chemistry at the University of Pretoria from 2000 to 2004. In 2005 he was appointed Extraordinary Professor at the Centre for Advancement of Scholarship, University of Pretoria.
Boeyens married Martha Hunter in 1960. They had three children, Jan, Aletta and Larisa. [ 3 ] He died on 28 August 2015 in Broederstroom, North West, South Africa after returning home from a crystallography conference. [ 4 ]
Boeyens belonged to the followings societies: [ 2 ]
He received the following awards: [ 2 ]
The first Jan Boeyens Medal for outstanding young scientists (younger than 40 years) in theoretical Chemistry or Physics was awarded to Prof Gideon Steyl from the University of the Free State Chemistry department in 2009. [ 5 ]
Boeyens authored 7 books [ 6 ] and more than 270 other publications. [ 7 ] His books are listed below.
In some of his books and articles Boeyens held some dissident views [ 8 ] on several subjects:
Numerologists can interpret great historical and cosmic events, predict the future and explain human nature. [ 9 ]
Volumes have been written about the red herring known as Schrödinger’s cat . Without science writers looking for sensation, it is difficult to see how such nonsense could ever become a topic for serious scientific discussion. [ 10 ]
He was also a strong believer in practical work to obtain tangible results over theoretical calculations:
All advances in chemistry happen at the bench, as it should, but without the theoretical understanding, even of common events such as intramolecular rearrangement. No calculation can predict chemical reactions. [ 10 ]
His book Number Theory and the Periodicity of Matter (co-authored with Demetrius C. Levendis) references the work of Peter Plichta. In it they try to replace modern quantum physics with elementary number theory, but unlike Plichta they do not question the general theory of relativity :
It is a myth that chemistry derives from quantum theory. More fundamental than both is the periodic table that reduces the properties of matter to a number basis, which is revealed only peripherally in the differential equations of quantum theory. [ 9 ] | https://en.wikipedia.org/wiki/Jan_C._A._Boeyens |
Jan A. Nolta is an American scientist and the director of the stem cell program at the UC Davis School of Medicine and Institute for Regenerative Cures. She is Scientific Director for the UC Davis Good Manufacturing Practice and editor of the journal Stem Cells . Nolta is known for her work with stem cell-related regenerative medicine . Nolta's current research focuses on treatment of Huntington's disease using mesenchymal stem cells . She was elected a AAAS Fellow in 2013. [ 1 ]
Nolta received a Bachelor of Science degree in biology from California State University, Sacramento in 1984, took master’s classes at University of California, Davis , and later earned a Ph.D. in molecular microbiology from the University of Southern California . She was an assistant professor at USC Keck School of Medicine before becoming an associate professor at Washington University School of Medicine in St. Louis . After serving as scientific director of the Cell Processing and Gene Therapy Good Manufacturing Practice facility at Washington University in St. Louis , Nolta joined University of California, Davis in 2006. [ 2 ]
While working towards her masters at UC Davis, Nolta was hired by Donald Kohn at the Children's Hospital Los Angeles and worked on gene therapy procedures.
Nolta now serves as the director of the Stem Cell Program at the UC Davis School of Medicine, as well as the director of the UC Davis Institute for Regenerative Cures, a facility supported by the California Institute for Regenerative Medicine (CIRM). [ 3 ] [ 4 ]
Nolta's research focuses on human stem cells and regenerative medicine therapies. Nolta's work focuses primarily on neurodegenerative diseases, especially therapeutics for Huntington's disease. She also studies Parkinson's disease , ALS , Liver disease , lysosomal storage diseases , and peripheral vascular disease . [ 3 ] Her lab uses genetically engineered mesenchymal stem cells from the bone marrow of healthy donors to transport enzymes and proteins to other cells. [ 4 ]
Nolta has acted as editor and editorial board member on eight scientific journals, including Stem Cells . She has published numerous peer-reviewed scientific journals and book chapters, and served on review panels for the National Institutes of Health and other grant-funding agencies. [ 2 ] | https://en.wikipedia.org/wiki/Jan_Nolta |
Jan Trlifaj (born 30 December 1954) is a professor of Mathematics at Charles University whose research interests include Commutative algebra , Homological algebra and Representation theory . [ 1 ]
Jan Trlifaj studied mathematics at the Faculty of Mathematics and Physics, Charles University , from which he received MSc. in 1979, Ph.D. in 1989 under Ladislav Bican. [ 2 ] and Prof. of Mathematics in the field Algebra and number theory in 2009.
In the academic year 1994/95 he had the position as Postdoctoral Fellow of the Royal Society at Department of Mathematics at University of Manchester. In Fall 1998 he received the J.W.Fulbright Scholarship at the Department of Mathematics, University California at Irvine. During Fall 2002 and 2006 he was a visiting professor at Centre de Recerca Matemàtica , Barcelona.
Since 1990, he has completed numerous short term visiting appointments and given over 100 invited lectures at conferences and seminars worldwide. [ 3 ]
Since 2017, he is Fellow of Learned Society of the Czech Republic . [ 4 ]
He served in the organizing committee of 18th International Conference on
Representations of Algebras (ICRA 2018), held for 250 participants from 34 countries in August 2018 in Prague, Czech Republic. [ 5 ]
He has been elected Fellow of the American Mathematical Society (AMS) in 2020, for contributions to homological algebra and tilting theory for non finitely generated modules. [ 6 ]
He serves as Member of the Science board for Neuron prize that is awarded to best Czech scientists by Neuron Endowment Fund. [ 7 ]
[[Category:21st-century Czech mathematicians]] | https://en.wikipedia.org/wiki/Jan_Trlifaj |
Jane is a discontinued GUI -based integrated software package for the Apple II , [ 1 ] Commodore 64 and Commodore 128 personal computers. It was developed by Arktronics in 1984, and the Commodore version was published by Commodore in 1985. The same year, it was also published for the French computer Thomson MO5 . Like Commodore's earlier Magic Desk software, it used a literal desktop metaphor with the interface consisting of an onscreen graphic of a desktop with icons representing associated business tools: a typewriter represented the word processor component (JaneWrite), a filing cabinet for the database (JaneList), a calculator for the spreadsheet (JaneCalc) and so on. It was designed to be controlled by either a joystick , a mouse or a light pen . Like most of the other examples of integrated software for home computers , Jane's components were criticized for being slow and limited. [ 2 ] [ 3 ] It was not a success in the marketplace but represented an early example of a graphical interface on an 8-bit computer.
Arktronics was a software development company in Ann Arbor, Michigan , founded by Howard Marks and Bobby Kotick . Jane was originally intended to be a package not only for the Apple and Commodore lines, but also for Atari 8-bit computers and others. This transportability was engineered by a combination of higher level systems written in the C language and machine specific drivers written in the assembly language for each machine (6502 Assembly for the Apple II and Commodore 64). For the C64, DOS manager was written by Howard K. Weiner, and the font manager/windows manager was written by Daniel J. Weiner. The Weiner brothers, both went on to attend the University of Michigan Integrated Pre-medical-Medical (Inteflex) Program. Other programmers included Andrew Marcheff and Thomas Naughton. [ citation needed ]
This software article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jane_(software) |
Jane Osbourn , OBE, is a scientist and former chair of the UK BioIndustry Association. [ 1 ]
A Natural Sciences graduate of Queens' College, Cambridge , Osbourn completed several post-graduate qualifications before moving into industry at Cambridge Antibody Technology , that became MedImmune and AstraZeneca .
In the Queen's Birthday Honours list of 2019, Osbourn was awarded the Order of the British Empire medal for services to "Human Monoclonal Antibody Drug Research and Development and Biotechnology". [ 2 ]
Osbourn was born in Bingley , West Yorkshire, and attended Bingley Grammar School . She is married to John Richer, Professor of Physics at the Cavendish Laboratory, Cambridge. [ 3 ]
She is the sister of Professor Anne Osbourn FRS [ 4 ] who investigates plant natural product biosynthesis .
Osbourn went on to study at the Queens' College, Cambridge , where she obtained a 1st class degree in Natural Sciences (Biochemistry). She was recognised in 1986 for playing netball at Queens, [ 5 ] and was awarded both a third year Foundation Scholarship and The Henry Mosseri prize. [ 6 ]
She went on to complete a PhD degree at the John Innes Centre for Plant Science Research in Norwich , which resulted in the publication of Evidence that nucleocapsid disassembly and a later step in virus replication are inhibited in transgenic tobacco protoplasts expressing TMV coat protein . [ 7 ] Following this, she completed a post-doctoral position at Rutgers University , New Jersey , United States, undertaking research directed towards clarification of the sequence elements responsible for the translational enhancement effect conferred by the 5' untranslated region of Tobacco Mosaic Virus known as omega. [ 8 ]
Osbourn then moved into medical research through a British Heart Foundation Post-Doctoral Fellowship at the Department of Medicine at Addenbrooke's Hospital in Cambridge. [ 9 ]
In 1993 she moved to a small, Cambridge-based, start-up biotechnology company called Cambridge Antibody Technology . [ 10 ] CAT, as it was called, would pioneer the use of Phage Display technology that ultimately discovered important drugs such as Humira . [ 11 ]
She was the key author of several scientific papers, including Human Antibodies with Sub-nanomolar Affinities Isolated from a Large Non-immunized Phage Display Library, Nature Biotechnology, 1996 [ 12 ] and Human Antibodies by Design, Nature Biotechnology, 1998 . [ 13 ] She is co-author of several others pertaining to antibody discovery and development:
Osbourn is listed as an inventor on several patents, which are (in chronological order):
Osbourn also created a technique to assist with the discovery of proximity-guided selection of antibodies, so called Proximol. [ 30 ]
CAT was acquired by AstraZeneca in 2006 [ 31 ] and in the following year was merged with a US-based company called MedImmune [ 32 ] to form AstraZeneca’s global biologics R&D arm. During this time Osbourn began to speak about opportunities for diversity in science. [ 33 ]
In 2013, AstraZeneca announced its decision to relocate its headquarters to Cambridge , UK. [ 34 ] Jonathan Burroughs, of Creative Places, wrote in 2015 that Osbourn had an influence over this decision. [ 35 ]
In February 2019, it was announced that Osbourn would be leaving AstraZeneca. [ 36 ] Since November 2019, Osbourn has been Chief Scientific Office of antibody therapeutics discovery company Alchemab Therapeutics.
Her early interest in science has grown into a passion for science education, supporting and championing life science education programmes and she is established as an advisor and mentor to many young researchers in the life science sector. She has been acknowledged by a number of different pharmaceutical media groups for these qualities. [ citation needed ]
In 2014 Osbourn was elected to join the board of the BioIndustry Association, becoming Chair in 2016; [ 1 ] and in this role she has been working to support the development of the biotechnology sector in the UK. She also does this through her roles as a Director of Babraham Bioscience Technologies [ 44 ] and as a Director of Cambridge Enterprise, the technology transfer organisation for University of Cambridge. [ 45 ]
Osbourn has presented at a number of parliamentary Select Committees. At the Business, Innovation and Skills Committee, on Tuesday 13 May 2014, she gave evidence on behalf of AstraZeneca as it faced a potential takeover from Pfizer . [ 46 ] [ 47 ]
On 1 July that year, Osbourn gave evidence to the Science and Technology Select Committee: Priorities for Scientific Research. [ 48 ]
Osbourn has also has previously served as a Member of the UK Medical Research Council Industry Grant Award Assessment Panel. [ 49 ]
In 2018 the Nobel Prize for Chemistry was awarded jointly to Sir Greg Winter , George Smith and Frances Arnold . Winter received his award for the phage display of peptides and antibodies. [ 50 ] Sir Greg and David Chiswell had founded Cambridge Antibody Technology to exploit this science. Osbourn says of this time, "There was a cohort of really able intellect in Cambridge – in CAT and other companies, in the MRC LMB and in the University – and what happened was a condensation of that focus… Once we decided to make phage display work, we set some really tough goals and then just got on with it." [ 51 ] To recognise Jane’s contribution to the prize, she, along with David Chiswell and John McCafferty , accompanied Sir Greg to the Nobel ceremony. [ 51 ]
On 7 June 2019 she was awarded an OBE for services to Human Monoclonal Antibody Drug Research and Development and Biotechnology. [ 2 ] CEO of AstraZeneca , Pascal Soriot , said of the award "On behalf of AstraZeneca, I am delighted to congratulate Dr Jane Osbourn for her award of an OBE in recognition of her services to human monoclonal antibody drug research and development and biotechnology . This well-deserved honour reflects her contribution to biopharmaceutical science over more than 25 years, from Cambridge Antibody Technology to AstraZeneca and MedImmune . Jane’s leadership in UK life sciences includes championing the biotech sector through her position as chair of the BIA and contributing to the growth of the UK’s scientific ecosystem. I would also like to recognise her authentic commitment to building skills through STEM and education outreach, in particular for women in science". [ 52 ] [ 53 ] | https://en.wikipedia.org/wiki/Jane_Osbourn |
Since Dimitri Mendeleev formulated the periodic law in 1871, and published an associated periodic table of chemical elements , authors have experimented with varying types of periodic tables including for teaching, aesthetic or philosophical purposes.
Earlier, in 1869, Mendeleev had mentioned different layouts including short, medium, and even cubic forms. It appeared to him that the latter (three-dimensional) form would be the most natural approach but that "attempts at such a construction have not led to any real results". [ 2 ] [ n 1 ] On spiral periodic tables, "Mendeleev...steadfastly refused to depict the system as [such]...His objection was that he could not express this function mathematically." [ 4 ]
In 1934, George Quam, a chemistry professor at Long Island University, New York, and Mary Quam, a librarian at the New York Public Library compiled and published a bibliography of 133 periodic tables using a five-fold typology: I. short; II. long (including triangular); III. spiral; IV. helical, and V. miscellaneous.
In 1952, Moeller expressed disdain as to the many types of periodic table:
The literature is replete with suggested (and discarded) modifications of the M periodic table. In fact so many modifications have appeared that one is tempted to conclude that practically every author has his [sic] own concept of what a workable arrangement must be. Unfortunately, the majority of the tabulations proposed are either unwieldy or utterly worthless, and only a few valuable suggestions have been made. Geometry does not permit of an arrangement which is sufficiently ideal to serve all the required purposes equally well. Thus the many three-dimensional models, embracing globes, helices, cones, prisms, castles, etc., are interesting but lacking in utility. To a lesser extent, the more involved two-dimensional arrangements do little toward solving the difficulty, and essentially the only suggestions as to modifications which are truly constructive are those centering in reflection of electronic configurations.
Certainly the most useful of these modifications, and at the same time one of the earliest to be proposed, is the so-called long or [18-column]...table. [ 5 ]
In 1954, Tomkeieff referred to the three principal types of periodic table as helical, rectilinear, and spiral. He added that, "unfortunately there also a number of freaks". [ 6 ]
In 1974 Edward Mazurs , a professor of chemistry, published a survey and analysis of about seven hundred periodic tables that had been published in the preceding one hundred years; he recognized short, medium, long, helical, spiral, series tables, and tables not classified.
In 1999 Mark Leach, a chemist, inaugurated the INTERNET database of Periodic Tables. It has over 1200 entries as of May 2023. [ n 2 ] While the database is a chronological compilation, specific types of periodic tables that can be searched for are spiral and helical; 3-dimensional; and miscellaneous.
For convenience, periodic tables may be typified as either: 1. short; 2. triangular; 3. medium; 4. long; 5. continuous (circular, spiral, lemniscate, or helical); 6. folding; or 7. spatial. Tables that defy easy classification are counted as type 8. unclassified.
Short tables have around eight columns. This form became popular following the publication of Mendeleev's eight-column periodic table in 1871.
Also shown in this section is a modernized version of the same table.
Mendeleev and others who discovered chemical periodicity in the 1860s had noticed that when the elements were arranged in order of their atomic weights there was as an approximate repetition of physiochemical properties after every eight elements. Consequently, Mendeleev organized the elements known at that time into a table with eight columns. He used the table to predict the properties of then unknown elements. While his hit rate was less than 50% it was his successes that propelled the widespread acceptance of the idea of a periodic table of the chemical elements. [ 8 ] The eight-column style remains popular to this day, most notably in Russia, Mendeleev's country of birth.
An earlier attempt by John Newlands , an English chemist, to present the nub of the same idea to the London Chemical Society , in 1866, was unsuccessful; [ 9 ] members were less than receptive to theoretical ideas, as was the British tendency at the time. [ 10 ] He referred to his idea as the Law of Octaves , at one point drawing an analogy with an eight-key musical scale.
John Gladstone , a fellow chemist, objected on the basis that Newlands's table presumed no elements remained to be discovered. "The last few years had brought forth thallium, indium, caesium, and rubidium, and now the finding of one more would throw out the whole system." [ 9 ] He believed there was as close an analogy between the metals named in the last vertical column as in any of the elements standing on the same horizontal line.
Fellow English chemist Carey Foster humorously inquired of Newlands whether he had ever examined the elements according to the order of their initial letters. Foster believed that any arrangement would present occasional coincidences, but he condemned one which placed so far apart manganese and chromium, or iron from nickel and cobalt.
The advantages of the short form of periodic table are its compact size and that it shows the relationships between main group elements and transition metal groups
Its disadvantages are that it appears to group dissimilar elements, such as chlorine and manganese, together; the separation of metals and nonmetals is hard to discern; there are "inconsistencies in the grouping together of elements giving colorless, diamagnetic ions with elements giving colored, paramagnetic ions; and [a] lack of reasonable positions for hydrogen, the lanthanide elements, and the actinide elements." [ 11 ]
Some other notable short periodic tables include:
Triangular tables have column widths of 2-8-18-32 or thereabouts. An early example, appearing in 1882, was provided by Bayley. [ 27 ]
Through the use of connecting lines, such tables make it easier to indicate analogous properties among the elements.
In some ways they represent a form intermediate between the short and medium tables, since the average width of the fully mature version (with widths of 2+8+18+32 = 60) is 15 columns.
An early drawback of this form was to make predictions for missing elements based on considerations of symmetry. For example, Bayely considered the rare earth metals to be indirect analogues of other elements such as, for example, zirconium and niobium, a presumption which turned out to be largely unfounded. [ 28 ]
Advantages of this form are its aesthetic appeal, and relatively compact size; disadvantages are its width, the fact that it is harder to draw, and interpreting certain periodic trends or relationships may be more challenging compared to the traditional rectangular format.
Some other notable triangular periodic tables include:
Medium tables have around 18 columns. The popularity of this form is thought to be a result of it having a good balance of features in terms of ease of construction and size, and its depiction of atomic order and periodic trends. [ 43 ]
Deming's version of a medium table, which appeared in the first edition of his 1923 textbook "General Chemistry: An Elementary Survey Emphasizing Industrial Applications of Fundamental Principles", has been credited with popularizing the 18-column form. [ 44 ] [ n 6 ]
LeRoy [ 45 ] referred to Deming's table, "this...being better known as the 'eighteen columns'-form" as representing "a very marked improvement over the original Mendeleef type as far as presentation to beginning classes is concerned."
Merck and Company prepared a handout form of Deming's table, in 1928, which was widely circulated in American schools. By the 1930s his table was appearing in handbooks and encyclopedias of chemistry. It was also distributed for many years by the Sargent-Welch Scientific Company. [ 46 ] [ 47 ] [ 48 ]
The advantages of the medium form are that it correlates the positions of the elements with their electronic structures, accommodates the vertical, horizontal and diagonal trends that characterise the elements, and separates the metals and nonmetals; its disadvantages are that it obscures the relationships between main group elements and transition metals.
Some other notable medium tables include:
Long tables have around 32 columns. Early examples are given by Bassett (1892), [ 58 ] with 37 columns arranged albeit vertically rather than horizontally; Gooch & Walker (1905), [ 59 ] with 25 columns; and by Werner (1905), [ 60 ] with 33 columns.
In the first image in this section, of a so-called left step table:
The elements remain positioned in order of atomic number ( Z ).
The left step table was developed by Charles Janet , in 1928, originally for aesthetic purposes. That being said it shows a reasonable correspondence with the Madelung energy ordering rule this being a notional sequence in which the electron shells of the neutral atoms in their ground states are filled.
A more conventional long form of periodic table is included for comparison.
The advantage of the long form is that shows where the lanthanides and actinides fit into the periodic table; its disadvantage is its width.
Some other notable long tables include:
Encompassing circular, spiral , lemniscate , or helical tables.
Crookes's lemniscate periodic table, shown in this section, has the following elements falling under one another:
The collocation of manganese with iron, nickel and cobalt is later seen in the modernised version of von Bichowsky's table of 1918, in the unclassified section of this article.
The French geologist Alexandre-Émile Béguyer de Chancourtois was the first person to make use of atomic weights to produce a classification of periodicity. He drew the elements as a continuous spiral around a metal cylinder divided into 16 parts. [ 73 ] The atomic weight of oxygen was taken as 16 and was used as the standard against which all the other elements were compared. Tellurium was situated at the centre, prompting vis tellurique , or telluric screw .
The advantage of this form is that it emphasizes, to a greater or lesser degree, that the elements form a continuous sequence; that said, continuous tables are harder to construct, read and memorize than the traditional rectangular form of periodic table.
Some other notable forms of continuous periodic tables include:
Such tables, which incorporate a folding mechanism, are relatively uncommon:
The advantages of such tables are their novelty and that they can depict relationships that ordinarily require spatial periodic tables, yet retain the portability and convenience of two-dimensional tables. A disadvantage is that they require marginally more effort to construct.
Spatial tables pass through three or more dimensions (helical tables are instead classed as continuous tables). Such tables are relatively niche and not as commonly used as traditional tables. While they offer unique advantages, their complexity and customization requirements make them more suitable for specialized research, advanced education, or specific areas of study where a deeper understanding of multidimensional relationships is desired.
Advantages of periodic tables of three or more dimensions include:
Disadvantages are:
Some other notable spatial periodic tables include:
Unclassified periodic tables defy easy classification: | https://en.wikipedia.org/wiki/Janet's_Left_Step_periodic_table |
Janet E. Mertz (born 1949) is an American biochemist, molecular biologist, and cancer researcher. [ 3 ] She is currently the Elizabeth McCoy Professor of Oncology in the McArdle Laboratory for Cancer Research at the University of Wisconsin–Madison . [ 4 ] Mertz is best known for disputing Lawrence Summers ' 2005 suggestion that women lack the intrinsic aptitude to excel in mathematics at the highest level [ 5 ] [ 6 ] [ 7 ] [ 8 ] and for discovering an easy method for joining DNAs from different species . [ 9 ] [ 10 ] [ 11 ] [ 12 ] This latter finding initiated the era of genetic engineering whose ramifications form the basis of modern genetics and the biotechnology industry.
After completing bachelor's degrees in biology and electrical engineering at the Massachusetts Institute of Technology, Mertz attended graduate school at Stanford University from 1970 to 1975, earning a Ph.D. in Biochemistry . Also in the year 1970, Mertz joined Paul Berg 's lab which was located in the biochemistry department at Stanford. [ 13 ] Berg said that Mertz was "as smart as all hell." [ 13 ] While taking a course held at the Cold Spring Harbor Laboratory in summer 1971, she mentioned her plan to grow mutants of the oncovirus , SV40 , by molecular cloning of them in the human gut bacterium , E. coli . This event led, initially, to a voluntary moratorium on cloning of viral oncogenes and, later on, the cloning of any DNA that might contain potentially biohazardous materials until theoretical safety concerns could be addressed and guidelines for their safe use could be developed and implemented.
In the interim, in collaboration with Ronald W. Davis , Mertz discovered that DNA ends generated by cutting with the EcoRI restriction enzyme are "sticky", permitting any two such DNAs to be readily "recombined". Using this discovery, in June 1972 she created the first recombinant DNA that could have been cloned in bacteria. [ 14 ] [ 15 ] [ 16 ] Her success with this project contributed to her thesis adviser, Paul Berg , receiving the 1980 Nobel Prize in Chemistry . [ 17 ] However, Mertz did not proceed with this cloning because of the moratorium in place at that time, leaving it for Herbert Boyer , Stanley N. Cohen and their colleagues to prove in 1973 that recombinant DNAs made by this method can actually self-replicate in bacteria. [ 18 ] Thus, most of Mertz's Ph.D. thesis centered, instead, around developing other ways to create, select, and grow mutants of SV40 for studying this virus' functions and so it could be used as the first eukaryotic cloning vector . [ 19 ] The US Patent 4,237,224, "Process for Producing Biologically Functional Molecular Chimeras", which generated over $250 million in licensing and royalty income, listed only Boyer and Cohen as co-inventors. [ 12 ] [ 20 ] Some have questioned whether these patents were valid given the earlier publications by Peter Lobban and A. Dale Kaiser [ 21 ] [ 22 ] and the Berg laboratory [ 14 ] [ 23 ] that were already in the public domain at the time this application was filed in November 1974. [ 12 ] [ 24 ]
Mertz spent 15 months as a postdoctoral researcher at the Medical Research Council . In collaboration with John B. Gurdon and Edward M. De Robertis , she showed that biological macromolecules injected into frog oocytes are properly used, providing the first way to study many aspects of gene expression in a higher eukaryote . [ 25 ] [ 26 ]
Mertz has been a member of the University of Wisconsin - Madison faculty since 1976. Her laboratory studies regulation of expression of the genes of the DNA oncoviruses SV40, hepatitis B virus , and Epstein–Barr virus and the roles the nuclear receptor estrogen-related receptor α plays in breast cancer and regulating the activities of estrogen receptor α. | https://en.wikipedia.org/wiki/Janet_E._Mertz |
Janet Gretchen Osteryoung (March 1, 1939 – September 21, 2021) was an American chemist who was the director of the Chemistry Division of the National Science Foundation from 1994 to 2001. Her research furthered the development of electroanalysis and especially that of square wave voltammetry . She was elected a Fellow of the American Association for the Advancement of Science in 1984 and awarded the Garvan–Olin Medal in 1987.
Janet Gretchen Jones was born in Pittsburgh, Pennsylvania , and grew up in Vero Beach, Florida . [ 1 ] She was an undergraduate student at Swarthmore College , where she was a Merit scholar. [ 2 ] Jones was a graduate student at California Institute of Technology , [ 3 ] where she worked alongside Fred Anson on ligand bridging in charge transfer reactions. [ 4 ] Robert Osteryoung was a Visiting Associate in the Department of Chemistry at Caltech at this same time. After marrying, Janet and Robert Osteryoung both continued to carry out research in the field of electroanalytical chemistry.
Osteryoung was appointed to the faculty at Montana State University in 1967. [ 3 ] She moved to Colorado State University a year later, where she worked in the Departments of Civil Engineering and Microbiology. [ 3 ] In 1977, Osteryoung moved to the National Science Foundation , where she was the program director for chemical analysis. [ 5 ]
Osteryoung was made associate professor at the State University of New York at Buffalo in 1979 and professor in 1982. In 1985 Osteryoung was awarded a Guggenheim Fellowship and spent a year at the University of Southampton , where she investigated the fundamentals of solid electrodes. [ 5 ]
Osteryoung moved to North Carolina State University in 1992, where she served as head of department for two years. [ 6 ] In 1994, she returned to the National Science Foundation, where she was made director of the division of chemistry. She was the first woman to win the Jacob F. Schoellkopf medal in 1992. [ 7 ]
Janet Jones was once married to Robert Osteryoung, who was also an award-winning chemist. [ 16 ] In April 2010, she married Chris Cobb in Washington, D.C. [ 1 ] [ 17 ] Together, Jones and Cobb established the Comis Foundation, a family philanthropic foundation to benefit children and youth. [ 18 ] | https://en.wikipedia.org/wiki/Janet_G._Osteryoung |
In mathematics, a Janet basis is a normal form for systems of linear homogeneous partial differential equations (PDEs) that removes the inherent arbitrariness of any such system. It was introduced in 1920 by Maurice Janet . [ 1 ] It was first called the Janet basis by Fritz Schwarz in 1998. [ 2 ]
The left hand sides of such systems of equations may be considered as differential polynomials of a ring, and Janet's normal form as a special basis of the ideal that they generate. By abuse of language, this terminology will be applied both to the original system and the ideal of differential polynomials generated by the left hand sides. A Janet basis is the predecessor of a Gröbner basis introduced by Bruno Buchberger [ 3 ] for polynomial ideals. In order to generate a Janet basis for any given system of linear PDEs a ranking of its derivatives must be provided; then the corresponding Janet basis is unique. If a system of linear PDEs is given in terms of a Janet basis its differential dimension may easily be determined; it is a measure for the degree of indeterminacy of its general solution. In order to generate a Loewy decomposition of a system of linear PDEs its Janet basis must be determined first.
Any system of linear homogeneous PDEs is highly non-unique, e.g. an arbitrary linear combination of its elements may be added to the system without changing its solution set. A priori it is not known whether it has any nontrivial solutions. More generally, the degree of arbitrariness of its general solution is not known, i.e. how many undetermined constants or functions it may contain. These questions were the starting point of Janet's work; he considered systems of linear PDEs in any number of dependent and independent variables and generated a normal form for them. Here mainly linear PDEs in the plane with the coordinates x {\displaystyle x} and y {\displaystyle y} will be considered; the number of unknown functions is one or two. Most results described here may be generalized in an obvious way to any number of variables or functions. [ 4 ] [ 5 ] [ 6 ] In order to generate a unique representation for a given system of linear PDEs, at first a ranking of its derivatives must be defined.
Definition :
A ranking of derivatives is a total ordering such that for any two derivatives δ {\displaystyle \delta } , δ 1 {\displaystyle \delta _{1}} and δ 2 {\displaystyle \delta _{2}} , and any derivation operator θ {\displaystyle \theta } the relations δ ≤ θ δ {\displaystyle \delta \leq \theta \delta } and δ 1 ≤ δ 2 → δ δ 1 ≤ δ δ 2 {\displaystyle \delta _{1}\leq \delta _{2}\rightarrow \delta \delta _{1}\leq \delta \delta _{2}} are valid.
A derivative δ 2 {\displaystyle \delta _{2}} is called higher than δ 1 {\displaystyle \delta _{1}} if δ 2 > δ 1 {\displaystyle \delta _{2}>\delta _{1}} . The highest
derivative in an equation is called its leading derivative . For the derivatives up to order two of a single function z {\displaystyle z} depending on x {\displaystyle x} and y {\displaystyle y} with x > y {\displaystyle x>y} two possible order are
Here the usual notation ∂ x z = z x , ∂ y z = z y , … {\displaystyle \partial _{x}z=z_{x},\partial _{y}z=z_{y},\ldots } is used. If the number of functions is higher than one, these orderings have to be generalized appropriately, e.g. the orderings T O P {\displaystyle TOP} or P O T {\displaystyle POT} may be applied. [ 7 ] The first basic operation to be applied in generating a Janet basis is the reduction of an equation e 1 {\displaystyle e_{1}} w.r.t. another one e 2 {\displaystyle e_{2}} . In colloquial terms this means the following: Whenever a derivative of e 1 {\displaystyle e_{1}} may be
obtained from the leading derivative of e 2 {\displaystyle e_{2}} by suitable differentiation, this differentiation is performed and the
result is subtracted from e 1 {\displaystyle e_{1}} . Reduction w.r.t. a system of PDEs means reduction w.r.t. all elements of the system. A system of linear PDEs is called autoreduced if all possible reductions have been performed.
The second basic operation for generating a Janet basis is the inclusion of integrability conditions . They are obtained as follows: If two equations e 1 {\displaystyle e_{1}} and e 2 {\displaystyle e_{2}} are such that by suitable differentiations two new equations may be obtained with like leading derivatives, by cross-multiplication with its leading coefficients and subtraction of the resulting equations a new equation is obtained, it is called an integrability condition. If by reduction w.r.t. the remaining equations of the system it does not vanish it is included as a new equation to the system.
It may be shown that repeating these operations always terminates after a finite number of steps with a unique answer which is called the Janet basis for the input system. Janet has organized them in terms of the following algorithm.
Janet's algorithm : Given a system of linear differential polynomials S ≡ { e 1 , e 2 , … } {\displaystyle S\equiv \{e_{1},e_{2},\ldots \}} , the Janet basis corresponding to S {\displaystyle S} is returned.
Here A u t o r e d u c e {\displaystyle Autoreduce} is a subalgorithm that returns its argument with all possible reductions performed, C o m p l e t i o n {\displaystyle Completion} adds certain equations to the system in order to facilitate determining the integrability conditions. To this end the variables are divides into multipliers and non-multipliers ; details may be found in the above references. Upon successful termination a Janet basis for the input system will be returned.
Example 1 : Let the system { e 1 ≡ z x y − x 2 y 2 z x − x − y y 2 z = 0 , e 2 ≡ z x + 1 x z y + x z = 0 } {\displaystyle \left\{e_{1}\equiv z_{xy}-{\frac {x^{2}}{y^{2}}}z_{x}-{\frac {x-y}{y^{2}}}z=0,e_{2}\equiv z_{x}+{\frac {1}{x}}z_{y}+xz=0\right\}} be given with ordering GRLEX and x > y {\displaystyle x>y} . Step S1 returns the autoreduced system
Steps S3 and S4 generate the integrability condition c 3 , 2 ≡ ∂ e 3 ∂ x − ∂ 2 e 2 ∂ y 2 {\displaystyle c_{3,2}\equiv {\frac {\partial e_{3}}{\partial x}}-{\frac {\partial ^{2}e_{2}}{\partial y^{2}}}} and reduces it to z = 0 {\displaystyle z=0} , i.e. the Janet basis for the originally given system is { z = 0 } {\displaystyle \{z=0\}} with the trivial solution z = 0 {\displaystyle z=0} .
The next example involves two unknown functions w {\displaystyle w} and z {\displaystyle z} , both depending on x {\displaystyle x} and y {\displaystyle y} .
Example 2 : Consider the system
in GRLEX, w > z , x > y {\displaystyle w>z,x>y} ordering. The system is already autoreduced, i.e. step S1 returns it unchanged. Step S3 generates the two integrability conditions
Upon reduction in step S4 they are
In step S5 they are included into the system and the algorithms starts again with step S1 with the extended system. After a few more iterations finally the Janet basis { z y + 1 2 x w = 0 , z x = 0 , w y = 0 , w x − 1 x w = 0 } {\displaystyle \left\{z_{y}+{\frac {1}{2x}}w=0,z_{x}=0,w_{y}=0,w_{x}-{\frac {1}{x}}w=0\right\}}
is obtained. It yields the general solution z = C 1 − C 2 x , w = 2 C 2 y {\displaystyle z=C_{1}-C_{2}x,w=2C_{2}y} with two undetermined constants C 1 {\displaystyle C_{1}} and C 2 {\displaystyle C_{2}} .
The most important application of a Janet basis is its use for deciding the degree of indeterminacy of a system of linear homogeneous partial differential equations. The answer in the above Example 1 is that the system under consideration allows only the trivial solution. In the second Example 2 a two-dimensional solution space is obtained. In general, the answer may be more involved, there may be infinitely many free constants in the general solution; they may be obtained from the Loewy decomposition of the respective Janet basis. [ 8 ] Furthermore, the Janet basis of a module allows to read off a Janet basis for the syzygy module. [ 5 ]
Janet's algorithm has been implemented in Maple. [ 9 ] | https://en.wikipedia.org/wiki/Janet_basis |
Jani Ingram is a professor of chemistry and biochemistry at Northern Arizona University . Ingram researches the chemistry and health impacts of environmental pollutants, especially uranium and arsenic. Ingram is a member of the Navajo tribe, and the Naneesht’ezhi clan. [ 1 ] She leads the Bridging Arizona Native American Students to Bachelor's Degrees (NIH Bridges to Baccalaureate) program and the Native American Cancer Prevention Program. She promotes educational and professional opportunities for Native American students in chemistry through a number of initiatives and for this work was awarded the 2018 American Chemical Society Award for Encouraging Disadvantaged Students into Careers in the Chemical Sciences. [ 2 ]
Ingram began her academic studies at Yavapai Community College in Arizona where she earned an associate's degree. She subsequently studied at New Mexico State University and earned a bachelor's degree in chemistry. [ 3 ] Her Ph.D. is in chemistry from the University of Arizona . [ 4 ]
Ingram's research areas are analytical chemistry and environmental chemistry . She specializes on environmental uranium and arsenic contamination and how they effect the food chain and water supplies of the Navajo nation. [ 5 ] [ 6 ] She also researches traditional Navajo food ingredients and their health benefits, for example juniper ash as a calcium source. [ 7 ] In light of the COVID-19 pandemic , her research laboratory repurposed their facilities to produce hand sanitizer which was donated to the Navajo Nation . [ 8 ] | https://en.wikipedia.org/wiki/Jani_Ingram |
Janice Musfeldt is a professor at University of Tennessee, Knoxville in physical and materials chemistry and experimental physics . She received her B.S. degree in chemical engineering from the University of Illinois in 1987 and a Ph.D. in physical chemistry from the University of Florida in 1992. [ 1 ] She served as a post-doctoral research associate at the Departement de Physique, Universite de Sherbrooke in 1993-1994. She received the 2001 Creativity award from the Division of Materials Research, National Science Foundation and the 2010 Chancellor's award for research and creative achievement at the University of Tennessee . [ 1 ] She has served on the user committee of the National High Magnetic Field Laboratory between 2010 and 2013 and between 2018 and the present [ 2 ] and was elected its chair in 2010. [ 3 ] In 2014 she founded the biannual Gordon Research Conference on Multiferroics and Magnetoelectric materials. [ 4 ] In 2017, she was elected as a Fellow of the American Physical Society for her contribution to the spectroscopy of quantum materials with an emphasis on high magnetic field effects in multiferroics, quantum magnets, and nanomaterials. [ 5 ]
This biographical article about a scientist is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Janice_Musfeldt |
In biochemistry, a Janin plot , like a Ramachandran plot , is a way to visualize dihedral angle distributions in protein structures. While a Ramachandran plot relates the two backbone dihedral angles, a Janin plot relates the first side chain dihedral angle χ-1 against χ-2. Because not all amino acids have these dihedral angles, a Janin plot is not applicable to all such acids.
This correlation is different for the various amino acids and can depend on the type of secondary structure (Helix, Sheet, etc.) local to that residue. The plot is named for Joël Janin, who studied these correlations in 1978 with Shoshana Wodak . [ 1 ] | https://en.wikipedia.org/wiki/Janin_Plot |
In mathematics , Janiszewski's theorem , named after the Polish mathematician Zygmunt Janiszewski , is a result concerning the topology of the plane or extended plane. It states that if A and B are closed subsets of the extended plane with connected intersection, then any two points that can be connected by paths avoiding either A or B can be connected by a path avoiding both of them. The theorem has been used as a tool for proving the Jordan curve theorem [ 1 ] and in complex function theory .
This topology-related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Janiszewski's_theorem |
The jansky (symbol Jy , plural janskys ) is a non- SI unit of spectral flux density , [ 1 ] or spectral irradiance , used especially in radio astronomy . It is equivalent to 10 −26 watts per square metre per hertz .
The spectral flux density or monochromatic flux , S , of a source is the integral of the spectral radiance, B , over the source solid angle : S = ∬ source B ( θ , ϕ ) d Ω . {\displaystyle S=\iint \limits _{\text{source}}B(\theta ,\phi )\,\mathrm {d} \Omega .}
The unit is named after pioneering US radio astronomer Karl Guthe Jansky and is defined as
Since the jansky is obtained by integrating over the whole source solid angle, it is most simply used to describe point sources; for example, the Third Cambridge Catalogue of Radio Sources (3C) reports results in janskys.
Jansky units are not a standard SI unit, so it may be necessary to convert the measurements made in the unit to the SI equivalent in terms of watts per square metre per hertz (W·m −2 ·Hz −1 ). However, other unit conversions are possible with respect to measuring this unit.
The flux density in janskys can be converted to a magnitude basis, for suitable assumptions about the spectrum. For instance, converting an AB magnitude to a flux density in microjanskys is straightforward: [ 4 ] S v [ μ Jy ] = 10 6 ⋅ 10 23 ⋅ 10 − AB + 48.6 2.5 = 10 23.9 − AB 2.5 . {\displaystyle S_{v}~[\mathrm {\mu } {\text{Jy}}]=10^{6}\cdot 10^{23}\cdot 10^{-{\tfrac {{\text{AB}}+48.6}{2.5}}}=10^{\tfrac {23.9-{\text{AB}}}{2.5}}.}
The linear flux density in janskys can be converted to a decibel basis, suitable for use in fields of telecommunication and radio engineering.
1 jansky is equal to −260 dBW ·m −2 ·Hz −1 , or −230 dBm ·m −2 ·Hz −1 : [ 5 ] P dBW ⋅ m − 2 ⋅ Hz − 1 = 10 log 10 ( P Jy ) − 260 , P dBm ⋅ m − 2 ⋅ Hz − 1 = 10 log 10 ( P Jy ) − 230. {\displaystyle {\begin{aligned}P_{{\text{dBW}}\cdot {\text{m}}^{-2}\cdot {\text{Hz}}^{-1}}&=10\log _{10}\left(P_{\text{Jy}}\right)-260,\\P_{{\text{dBm}}\cdot {\text{m}}^{-2}\cdot {\text{Hz}}^{-1}}&=10\log _{10}\left(P_{\text{Jy}}\right)-230.\end{aligned}}}
The spectral radiance in janskys per steradian can be converted to a brightness temperature , useful in radio and microwave astronomy.
Starting with Planck's law , we see B ν = 2 h ν 3 c 2 1 e h ν / k T − 1 . {\displaystyle B_{\nu }={\frac {2h\nu ^{3}}{c^{2}}}{\frac {1}{e^{h\nu /kT}-1}}.} This can be solved for temperature, giving T = h ν k ln ( 1 + 2 h ν 3 B ν c 2 ) . {\displaystyle T={\frac {h\nu }{k\ln \left(1+{\frac {2h\nu ^{3}}{B_{\nu }c^{2}}}\right)}}.} In the low-frequency, high-temperature regime, when h ν ≪ k T {\displaystyle h\nu \ll kT} , we can use the asymptotic expression : T ∼ h ν k ( B ν c 2 2 h ν 3 + 1 2 ) . {\displaystyle T\sim {\frac {h\nu }{k}}\left({\frac {B_{\nu }c^{2}}{2h\nu ^{3}}}+{\frac {1}{2}}\right).}
A less accurate form is T b = B ν c 2 2 k ν 2 , {\displaystyle T_{b}={\frac {B_{\nu }c^{2}}{2k\nu ^{2}}},} which can be derived from the Rayleigh–Jeans law B ν = 2 ν 2 k T c 2 . {\displaystyle B_{\nu }={\frac {2\nu ^{2}kT}{c^{2}}}.}
The flux to which the jansky refers can be in any form of radiant energy .
It was created for and is still most frequently used in reference to electromagnetic energy, especially in the context of radio astronomy.
The brightest astronomical radio sources have flux densities of the order of 1–100 janskys. For example, the Third Cambridge Catalogue of Radio Sources lists some 300 to 400 radio sources in the Northern Hemisphere brighter than 9 Jy at 159 MHz. This range makes the jansky a suitable unit for radio astronomy .
Gravitational waves also carry energy, so their flux density can also be expressed in terms of janskys. Typical signals on Earth are expected to be 10 20 Jy or more. [ 6 ] However, because of the poor coupling of gravitational waves to matter, such signals are difficult to detect.
When measuring broadband continuum emissions, where the energy is roughly evenly distributed across the detector bandwidth , the detected signal will increase in proportion to the bandwidth of the detector (as opposed to signals with bandwidth narrower than the detector bandpass). To calculate the flux density in janskys, the total power detected (in watts) is divided by the receiver collecting area (in square meters), and then divided by the detector bandwidth (in hertz). The flux density of astronomical sources is many orders of magnitude below 1 W·m −2 ·Hz −1 , so the result is multiplied by 10 26 to get a more appropriate unit for natural astrophysical phenomena. [ 7 ]
The millijansky, mJy, was sometimes referred to as a milli-flux unit (mfu) in older astronomical literature. [ 8 ]
Note: Unless noted, all values are as seen from the Earth's surface. [ 10 ] | https://en.wikipedia.org/wiki/Jansky |
The Janssen Medal is an astrophysics award presented by the French Academy of Sciences to those who have made advances in this area of science. [ 1 ]
The award was founded in 1886, though the first medal was not awarded until a year later. The commission formed to decide on the first recipient of the medal selected the German physicist Gustav Kirchhoff for his work on the science of spectroscopy . However, Kirchhoff died aged 63 on 17 October 1887, a few months before the award would have been announced. Rather than chose a new recipient for the award, the commission announced at the Academy's session of 26 December 1887 that the inaugural medal would be placed on his grave, in "supreme honour of the memory of this great scholar of Heidelberg". [ 2 ]
The award had been intended to be biennial, but was awarded in 1888 and again in 1889. A statement in the 1889 volume of Comptes rendus de l'Académie des sciences clarified that the award would be presented annually for the first seven years, and then biennially from 1894 onwards. [ 3 ]
This award is distinct from the Prix Jules Janssen (created in 1897), an annual award presented by the French Astronomical Society . Both awards are named for the French astronomer Pierre Janssen (1824–1907) (better known as Jules Janssen). Janssen founded the Academy award, and was a member of the inaugural commission.
The list above is complete up to 2019. | https://en.wikipedia.org/wiki/Janssen_Medal_(French_Academy_of_Sciences) |
The Janssen revolver ( French : revolver photographique ) was invented by the French astronomer Pierre Jules César Janssen in 1874. It was the instrument that originated chronophotography , a branch of photography based on capturing movement from a sequence of images. To create the apparatus Pierre Janssen was inspired by the revolving cylinder of Samuel Colt 's revolver. [ 1 ]
The revolver used two discs and a sensitive plate, the first with twelve holes ( shutter ) and the second with only one, on the plate. The first one would take a full turn every eighteen seconds, so that each time a shutter window passed in front of the window of the second (fixed) disk, the sensitive plate was discovered in the corresponding portion of its surface, creating an image. In order for the images not to overlap, the sensitive plate rotated with a quarter of the shutter speed. The Shutter Speed was one and a half seconds. A mirror on the outside of the apparatus reflected the movement of the object towards the lens that was located in the barrel of this photographic revolver. When the revolver was in operation it was capable of taking forty-eight images in seventy-two seconds.
In the mid-nineteenth century, one of the scientific challenges of the moment was to determine with the greatest accuracy possible the distance between the Earth and the Sun , the so-called Astronomical Unit , which indicates the size of the Solar System . At that time, the only way to know it was through the astronomical phenomenon of Venus transit : the passage of Venus ahead of the Sun, which required two simultaneous observations being made at a time from different land latitudes and measure the total duration of the event. With this data and applying the laws of Kepler , which describe the behavior of planetary orbits, the distance with the rest of the planets of the Solar System could be obtained.
The method had two drawbacks: the frequency of the phenomenon and technical problems of getting the start and end of the transit. The Venus transit in 1874 was a unique opportunity, which was why more than sixty co-ordinated expeditions from up to ten different countries were dispatched to locations in China, Vietnam, New Caledonia, some Pacific islands and Japan. The distortion caused by the terrestrial atmosphere, the diffraction of the telescopes, the subjectivity of the observer and the " black drop effect " (an optical effect that distorts the silhouette of Venus just in the instant that enters and leaves the solar disk) meant the attempt faced huge technical challenges, which had previously been insurmountable.
Janssen's invention of the photographic revolver was designed in an attempt to overcome these difficulties.
Janssen tested the device with the support of the French government in Nagasaki (Japan).
As the exact moment in which the transit of Venus would take place was impossible to predict, he added a watch set to create a sequence of images. The revolver recorded 48 photographs in 72 seconds in a daguerreotype , material that was no longer used but was ideal for the sunlight that was presented in the situation, since it could capture the light in a great time of exposure and obtain clearer results.
The British expeditions photographed the transit from different geographic points by using apparatuses inspired by the revolver of Janssen. [ 2 ] Unfortunately, the quality of the resulting images of the two expeditions was not sufficient to accurately calculate the Astronomical Unit , and the observations were more reliable at eye. Even so, Janssen introduced his revolver to the Société Francaise de Photographie in 1875 and the Académie des Sciences in 1876, to which he suggested the possibility of using his apparatus for the study of the animal movement, especially of the birds, because of the rapidity of the movement of their wings. [ 3 ]
In 1882, the physiologist Etienne-Jules Marey concluded that a galloping horse would have four legs in the air at a certain moment. Four years previously, Eadweard Muybridge was the first to record the movement of living beings, in The Horse in Motion , with 12 serialized cameras that allowed him to play and even project those photographs in a row. The action was not being reconstructed from the point of view of an observer, but from a camera that accompanied the subject - such as a tracking shot - and in which, in each photograph, the action had a different viewpoint. Marey , based on the invention of Janssen, managed to solve these problems with his 1882 photo gun, which captured 12 small photos on a circular plate and at regular intervals. This improvement allowed the image to be captured by a fragile glass plate, so that it was no longer used by the impractical daguerreotype , thus reducing the exposure time.
It was, therefore, the first camcorder , although it still had certain differences of conception with the later camcorders: On one hand, the obtained images had as a goal the decomposition of the movement for its study, and not for their projection; and on the other hand, being obtained on a glass disk, the duration of the action that could be recorded was necessarily very short. [ 4 ]
Both inventions were a first step in the development of the first film cameras, but they can not be considered as such because their main objective was not the projection of films, but to study movement as a result of its decomposition. [ citation needed ] | https://en.wikipedia.org/wiki/Janssen_revolver |
A Janus molecule (or Janus-faced molecule) is a molecule which can represent both beneficial and toxic effects. The term Janus-faced molecule is derived from the ancient Roman god, Janus. Janus is depicted as having two faces; one facing the past and one facing the future. [ 1 ] This is synonymous to a Janus molecule having two distinct purposes: a beneficial and a toxic purpose depending on its quantity.
Examples of a Janus-faced molecule are nitric oxide [ 2 ] and cholesterol . [ 3 ] In the case of cholesterol, the property that makes cholesterol useful in cell membranes, namely its absolute insolubility in water, also makes it lethal. When cholesterol accumulates in the wrong place, for example within the walls of an artery, it cannot be readily mobilized, and its presence eventually leads to the development of an atherosclerotic plaque.
One such example of a Janus-faced molecule is S100A8 / A9 protein complex; this complex is associated with autoimmune and abnormal growth of cells disorders. S100 is integral in the fight against cancer, S100 induces phagocytes that phagocytize malignant tumor cells which results in apoptosis. [ 4 ]
Proteoglycans are another class of molecules that display this duality, under certain chemical conditions these molecules can emerge as inhibitors or promoters. [ 5 ] Recent studies have shown that proteoglycans can play an integral role in the metastasis of cancer. Another molecule that falls within this class of molecules is DKK1. This molecule's presence can trigger cancers to display both metastatic as well as anti-metastatic properties especially pertaining to breast cancers. It has been studied that DKK1 secretion can be associated with promoting breast cancer metastasis to the bone as well as the suppression of metastasis to the lungs. [ 6 ] Botulinum neurotoxins also portray these dichotomous roles. This specific molecule is formed by Clostridium Botulinum, a spore forming bacteria. If this bacteria contaminates food, the results can be fatal and can lead to death. Yet, despite their toxicity which is lethal even in small doses, these molecules can be used in a wide array of pharmacological applications; one such application is the one utilized in cosmetology . [ 7 ]
Gamma peptide nucleic acid (PNA) (synthetic DNA and RNA analogs) is another Janus molecule which slips between DNA strands. [ 8 ] The gamma PNA could be inserted between strands of DNA or RNA to recognize sequences or elements that could potentially cause known diseases through its bifacial recognition. It does so by inserting itself when the DNA or RNA strand is undergoing transcription to conduction transcriptional regulation. However, there are still ongoing challenges with this Janus molecule that requires further research and experimentation. [ 9 ]
Some fungi are capable of producing secondary metabolites called mycotoxins which are toxic and affect human and animal health. [ 10 ] Mycotoxins are often found in farmed ingredients such as corn and rice while it is being harvested or kept in storage; When these ingredients are largely manufactured towards humans and animals, there is the possibly of consumption of these toxins. The toxicity of these mycotoxins were intensively studied and appeared to be affective in killing microbes as well as inhibiting/killing tumor cell growth. [ 11 ] This exhibits janus-faced molecule characteristics because it kills indiscriminitely. A consequence of using mycotoxins against tumor cell growth in cancer treatment is an increase risk of mutations. | https://en.wikipedia.org/wiki/Janus-faced_molecule |
Janus kinase ( JAK ) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine -mediated signals via the JAK-STAT pathway . They were initially named " just another kinase " 1 and 2 (since they were just two of many discoveries in a PCR -based screen of kinases), [ 1 ] but were ultimately published as "Janus kinase". The name is taken from the two-faced Roman god of beginnings, endings and duality, Janus , because the JAKs possess two near-identical phosphate-transferring domains. One domain exhibits the kinase activity, while the other negatively regulates the kinase activity of the first.
The four JAK family members are:
Transgenic mice that do not express JAK1 have defective responses to some cytokines, such as interferon-gamma . [ 2 ] JAK1 and JAK2 are involved in type II interferon (interferon-gamma) signalling, whereas JAK1 and TYK2 are involved in type I interferon signalling. Mice that do not express TYK2 have defective natural killer cell function. [ 3 ]
Since members of the type I and type II cytokine receptor families possess no catalytic kinase activity, they rely on the JAK family of tyrosine kinases to phosphorylate and activate downstream proteins involved in their signal transduction pathways. The receptors exist as paired polypeptides, thus exhibiting two intracellular signal-transducing domains.
JAKs associate with a proline -rich region in each intracellular domain that is adjacent to the cell membrane and called a box1/box2 region. After the receptor associates with its respective cytokine / ligand , it goes through a conformational change, bringing the two JAKs close enough to phosphorylate each other. The JAK autophosphorylation induces a conformational change within itself, enabling it to transduce the intracellular signal by further phosphorylating and activating transcription factors called STATs (Signal Transducer and Activator of Transcription, or Signal Transduction And Transcription) . [ 4 ] The activated STATs dissociate from the receptor and form dimers before translocating to the cell nucleus , where they regulate transcription of selected genes .
Some examples of the molecules that use the JAK/STAT signaling pathway are colony-stimulating factor , prolactin , growth hormone , and many cytokines . Janus Kinases have also been reported to have a role in the maintenance of X chromosome inactivation . [ 5 ]
JAK inhibitors are used for the treatment of atopic dermatitis and rheumatoid arthritis . They are also being studied in psoriasis , polycythemia vera , alopecia , essential thrombocythemia , ulcerative colitis , myeloid metaplasia with myelofibrosis and vitiligo . [ 6 ] [ 7 ] Examples are tofacitinib , baricitinib , upadacitinib and filgotinib . [ 8 ]
In 2014 researchers discovered that oral JAK inhibitors, when administered orally, could restore hair growth in some subjects and that applied to the skin, effectively promoted hair growth. [ 9 ]
JAKs range from 120-140 kDa in size and have seven defined regions of homology called Janus homology domains 1 to 7 (JH1-7). JH1 is the kinase domain important for the enzymatic activity of the JAK and contains typical features of a tyrosine kinase such as conserved tyrosines necessary for JAK activation (e.g., Y1038/Y1039 in JAK1, Y1007/Y1008 in JAK2, Y980/Y981 in JAK3, and Y1054/Y1055 in Tyk2). Phosphorylation of these dual tyrosines leads to the conformational changes in the JAK protein to facilitate binding of substrate . JH2 is a pseudokinase domain , a domain structurally similar to a tyrosine kinase and essential for a normal kinase activity, yet lacks enzymatic activity. This domain may be involved in regulating the activity of JH1, and was likely a duplication of the JH1 domain which has undergone mutation post-duplication. The JH3-JH4 domains of JAKs share homology with Src-homology -2 ( SH2 ) domains. The amino terminal (NH 2 ) end (JH4-JH7) of Jaks is called a FERM domain (short for band 4.1 , ezrin , radixin and moesin ); this domain is also found in the focal adhesion kinase (FAK) family and is involved in association of JAKs with cytokine receptors and/or other kinases. [ 4 ] | https://en.wikipedia.org/wiki/Janus_kinase |
The Janzen–Connell hypothesis is a well-known hypothesis for the maintenance of high species biodiversity in the tropics. It was published independently in the early 1970s by Daniel Janzen , [ 1 ] who focused on tropical trees, and Joseph Connell [ 2 ] who discussed trees and marine invertebrates. According to their hypothesis, host -specific herbivores , pathogens , or other natural enemies (sometimes also referred to as predators [ 1 ] ) make the areas near a parent tree (the seed-producing tree) inhospitable for the survival of seeds or seedlings. These natural enemies are referred to as 'distance-responsive predators' if they kill seeds or seedlings near the parent tree, or 'density-dependent predators' if they kill seeds or seedlings where they are most abundant (which is typically near the parent tree [ 1 ] ). Such predators can prevent any one species from dominating the landscape, because if that species is too common, there will be few safe places for its seedlings to survive. Both Janzen and Connell originally proposed that for natural enemies to increase local diversity, they must be host-specific (also called specialists ) and relatively immobile, such that they disproportionately reduce the density of the more locally common tree species. This prevents any one species from becoming dominant and excluding other species through competition, allowing more species to coexist in small areas. This can be classified as a stabilizing mechanism .
Notably, Janzen–Connell effects provide a recruitment advantage to locally-rare trees, since they act primarily on seeds and seedlings. These effects promote the establishment of rare tree species, but do nothing to ensure the survival of these species post-germination.
The Janzen–Connell hypothesis has been called a special case of keystone predation , predator partitioning or the pest pressure hypothesis. [ 3 ] [ 4 ] The pest pressure hypothesis states that plant diversity is maintained by specialist natural enemies. [ 5 ] The Janzen–Connell hypothesis expands on this, by claiming that the natural enemies are not only specialists, but also are distance-responsive or density-responsive. [ 1 ]
Both Connell and Janzen, [ 1 ] but particularly Connell, [ 2 ] proposed that natural enemies will be more likely to prevent competitive dominance in more climatically stable environments. This lead both authors to predict that natural enemies contribute to the latitudinal diversity gradient by promoting local coexistence of many species in the warm, stable, highly productive climates of the wet tropics. This does not negate that Janzen-Connell effects may also happen in temperate forests. The black cherry is one such example of a temperate forest species whose growth patterns can be explained by the Janzen–Connell hypothesis.
Daniel Janzen published his hypothesis in 1970 in The American Naturalist under the article "Herbivores and the Number of Tree Species in Tropical Forests." [ 1 ] His hypothesis was based on the observation that in tropical forests (when compared to temperate forests), there were few new adult trees in the immediate vicinity of their parent tree. He explained the low density of tropical trees and lack of "bunching" of tree types around parent trees for two reasons: (1) the number of seeds decline with distance from the parent tree and (2) that the adult tree, its seeds, and seedlings are a source of food for host-specific parasites and diseases.
Using his observations, Janzen created a model demonstrating the probability of a seed maturation or a seedling survival as a function of distance from the parent tree (as well as total seed count, dispersal mechanism, and predatory activity).
Joseph Connell published his hypothesis in 1970 in Dynamics of Populations . [ 2 ] Unlike Janzen, Connell proposed experiments that focused on the key prediction that exclusion of host-specific predators would cause a decrease in diversity as tree species with greater establishment or competitive ability formed low-diversity seedling and sapling communities where dominance was concentrated in a few species.
He formed his hypothesis through observations in Queensland , Australia. Along with Jack Greening Tracey and Larry Johnson Webb, he mapped trees in two rainforests and observed that smaller seedlings tended to occur in single-species clumps. Smaller seedlings also exhibited greater mortality , especially when their nearest neighbor was an individual of the same species. This pattern lessened with growth and age until seedlings exhibited similar pattern diversity to adults. To reinforce these observations, Connell ran an experiment showing that adult trees have a deleterious effect on smaller trees of the same species. In another experiment, Connell found that pre-germination predation was greater on seeds near adults of the same species than those near adults of others. Through these observations, Connell suggests that each tree species has host-specific enemies that attack it and any of its offspring which are close to the parent. This emphasizes the importance of the role of predation in preventing trees from forming single-species groves, which is probably the only way in which one species of tree could exclude others by interspecies competition.
Plant pathogens follow infectious disease dynamics . The basic reproductive rate ( R 0 ) {\displaystyle (R_{0})} of a disease is dependent on three variables such that:
R 0 = β LS where β is the transmission rate or infectiousness of the disease, L is the average infection time of the host, and S is the density of the host population. By decreasing any one of the variables, the reproduction rate of the disease decreases. Since seed dispersal is such that the highest density of seeds is around the parent with density decreasing with distance from the parent, the reproduction rate of a disease infecting seeds and seedlings will be highest around the parent and decrease with distance. Thus, seedlings close to the parent are likely to die due to the disease prevalence. However, seedlings farther away are less likely to encounter the disease and therefore will more likely grow into adults.
Specialist herbivores who consume plant matter can also be thought of as having a "transmission rate" between individuals similarly to a disease. Tree predators (especially herbivorous insects) are limited by the ease of movement. When individuals are closer together at high density, movement between trees is easier and the predators quickly spread out. However, at low tree density, predators can not find the next individual with as much ease and thus often have low transmission rates leading to less specialist predation.
Many studies examining the Janzen–Connell hypothesis have shown supporting patterns with a number of tree species, but despite this there are also problematic aspects of the hypothesis.
Many tests of the Janzen-Connell hypothesis focus on whether seed or seedling survival is lower when they are closer to a conspecific (same-species) tree (distance dependence) or when seeds or seedlings are closer to seeds or seedlings of the same species (density dependence), [ 11 ] rather than testing the prevalence or attack rates of natural enemies explicitly. Fewer studies assess the geographic implication that Janzen-Connell effects are stronger in the tropics.
There have been many studies designed to test predictions of this hypothesis in tropical and other settings. Studies that have supported the Janzen–Connell hypothesis include:
Studies questioning the Janzen–Connell hypothesis:
It is tricky to form conclusions regarding the accuracy of the Janzen–Connell hypothesis as it is difficult to falsify. This is because:
It is likely that a number of mechanisms underscore the coexistence of similar species and thus cause biodiversity in ecosystems. It is possible the Janzen–Connell hypothesis is applicable only for some species depending on species characteristics. The hypothesis may also be affected by the kind of predator or pathogen as preliminary research has shown that the hypothesis is true only when host-specific predators have limited mobility with a range less than the seed dispersal range. [ 19 ] | https://en.wikipedia.org/wiki/Janzen–Connell_hypothesis |
In fluid dynamics , Janzen–Rayleigh expansion represents a regular perturbation expansion using the relevant mach number as the small parameter of expansion for the velocity field that possess slight compressibility effects. The expansion was first studied by O. Janzen in 1913 [ 1 ] and Lord Rayleigh in 1916. [ 2 ]
Consider a steady potential flow that is characterized by the velocity potential φ ( x ) . {\displaystyle \varphi (\mathbf {x} ).} Then φ {\displaystyle \varphi } satisfies
where c = c ( v 2 ) {\displaystyle c=c(v^{2})} , the sound speed is expressed as a function of the velocity magnitude v 2 = ( ∇ φ ) 2 . {\displaystyle v^{2}=(\nabla \varphi )^{2}.} For a polytropic gas , we can write
where γ {\displaystyle \gamma } is the specific heat ratio , c 0 2 = h 0 ( γ − 1 ) / 2 {\displaystyle c_{0}^{2}=h_{0}(\gamma -1)/2} is the stagnation sound speed (i.e., the sound speed in a gas at rest) and h 0 {\displaystyle h_{0}} is the stagnation enthalpy . Let U {\displaystyle U} be the characteristic velocity scale and c 0 {\displaystyle c_{0}} is the characteristic value of the sound speed , then the function c ( v 2 ) {\displaystyle c(v^{2})} is of the form
where M = U / c 0 {\displaystyle M=U/c_{0}} is the relevant Mach number .
For small Mach numbers, we can introduce the series [ 3 ]
Substituting this governing equation and collecting terms of different orders of M a {\displaystyle Ma} leads to a set of equations. These are
and so on. Note that φ 1 {\displaystyle \varphi _{1}} is independent of γ {\displaystyle \gamma } with which the latter quantity appears in the problem for φ 2 {\displaystyle \varphi _{2}} .
A simple method for finding the particular integral for φ 1 {\displaystyle \varphi _{1}} in two dimensions was devised by Isao Imai and Ernst Lamla . [ 4 ] [ 5 ] [ 6 ] In two dimensions, the problem can be handled using complex analysis by introducing the complex potential f ( z , z ¯ ) = φ + i ψ {\displaystyle f(z,{\overline {z}})=\varphi +i\psi } formally regarded as the function of z = x + i y {\displaystyle z=x+iy} and its conjugate z ¯ = x − i y {\displaystyle {\overline {z}}=x-iy} ; here ψ {\displaystyle \psi } is the stream function , defined such that
where ρ ∞ {\displaystyle \rho _{\infty }} is some reference value for the density. The perturbation series of f {\displaystyle f} is given by
where f 0 = f 0 ( z ) {\displaystyle f_{0}=f_{0}(z)} is an analytic function since φ 0 {\displaystyle \varphi _{0}} and ψ 0 {\displaystyle \psi _{0}} , being solutions of the Laplace equation, are harmonic functions. The integral for the first-order problem leads to the Imai–Lamla formula [ 7 ] [ 8 ]
where F ( z ) {\displaystyle F(z)} is the homogeneous solution (an analytic function), that can be used to satisfy necessary boundary conditions. The series for the complex velocity potential g = u − i v {\displaystyle g=u-iv} is given by
where g 0 = d f 0 / d z {\displaystyle g_{0}=df_{0}/dz} and [ 9 ] | https://en.wikipedia.org/wiki/Janzen–Rayleigh_expansion |
The Japan Association for International Chemical Information (JAICI) ( 一般社団法人化学情報協会 , ippan shadanhoujin kagaku jouhou kyoukai ) is a nonprofit organization in Tokyo, Japan . It indexes chemical information and translates abstracts between Japanese and English. It works in collaboration with the Chemical Abstracts Service (CAS) in Columbus, Ohio . [ 1 ]
JAICI was founded with the help of Hideaki Chihara in 1971. It succeeded an earlier organization, the Japanese CA Abstractors' Association, which was started in 1954. [ 2 ]
This article about an organization or organization-related topic in Japan is a stub . You can help Wikipedia by expanding it .
This article about a chemistry organization is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Japan_Association_for_International_Chemical_Information |
The Japan Confederation of Petroleum Industry Workers' Unions ( Japanese : 全国石油産業労働組合連合会 , Sekiyu Roren) was a trade union representing workers in the oil industry in Japan.
The union was founded on 11 April 1947 as a loose council and became a more centralised federation in 1953. [ 1 ] It was initially known as the All Japan Oil Workers' Union (Zensekiyu). It was a founding affiliate of the Federation of Independent Unions (Churitsuroren), and by 1967, it had 24,611 members. [ 2 ] In the late 1980s, it became affiliated with the Japanese Trade Union Confederation , and by 1996 it had 29,505 members. [ 3 ] In 2002, it merged with the Japanese Federation of Chemistry Workers' Unions , the National Organization of All Chemical Workers , and the National Federation of Cement Workers' Unions of Japan to form the Japan Federation of Energy and Chemistry Workers' Unions . [ 4 ] | https://en.wikipedia.org/wiki/Japan_Confederation_of_Petroleum_Industry_Workers'_Unions |
The Japan Electric Association ( 日本電気協会 ) ( JEA ) is a membership organisation for the electricity sector in Japan and, although it has roots dating back to 1892, was founded in October 1921. [ 1 ] It currently has around 4,800 corporate and individual members. [ 1 ]
The JCA has a number of committees that set national technical guidelines (JEAGs), codes (JEACs) and standards covering areas ranging from electrical safety to the design of nuclear power stations [ 2 ] some of which are regarded as optional 'independent standards of the private sectors' while others have official status as the 'standards of academic societies and associations'. [ 3 ]
The JCA also acts as the main lobby group for the Japanese power companies [ 4 ] and is active in promoting nuclear power. [ 2 ]
Among its other work, the JCA promotes education, publishes a range of books and guides, and holds lectures, seminars and cultural events. [ 2 ] Since 1942 the ECA has published The Denki Shimbun (The Electric Daily News), founded in 1907 as the Electrical News. [ 5 ]
Through the work of its committees, the JCA prepares and publishes a number of codes and guides for the Japanese nuclear power industry , including the Rules of Quality Assurance for Safety of Nuclear Power Plants (JEAC 4111-2003) and the Guideline for Development and Design of Computerized Human-Machine Interface in the Central Control Room (JEAG 4617-2005), intended to meet the performance requirements specified under the Electricity Utilities Industry Law [ 3 ] As of 2007, the Nuclear and Industrial Safety Agency were engaged in the process of evaluating certain standards produced by the JEA and others for technical adequacy. [ 3 ]
There have been allegations that the JEA wields too much power in setting standards. Professor Katsuhiko Ishibashi , one of the seismologists on a Japanese government subcommittee that produced the 2006 Regulatory Guide for Reviewing Seismic Design of Nuclear Power Reactor Facilities [ 6 ] claimed that the review process was 'unscientific' [ 7 ] [ 8 ] and the outcome rigged [ 4 ] [ 8 ] to suit the interests of the JEA, which had 11 of its committee members on the 19-member government subcommittee [ 4 ] and that among other problems the guide was 'seriously flawed' as a consequence because it underestimated the design basis earthquake ground motion . [ 9 ]
Between 1923 and January 1, 1965, the JEA was one of the bodies authorised to inspect electricity meters , a function subsequently transferred to the Japan Electric Meters Inspection Corporation (JEMIC). [ 10 ]
The Japan Electrical Safety & Environment Technology Laboratories (JET) were founded as the Japan Electrical Testing Laboratories of Japan Electric Association in February 1963. [ 11 ] | https://en.wikipedia.org/wiki/Japan_Electric_Association |
The Japan Federation of Energy and Chemistry Workers' Unions ( Japanese : 日本化学エネルギー産業労働組合連合会 , JEC RENGO) is a trade union representing workers in various related industries in Japan.
The union was founded in October 2002, with the merger of the Japanese Federation of Chemistry Workers' Unions , the National Organization of All Chemical Workers , the Japan Confederation of Petroleum Industry Workers' Unions , and the National Federation of Cement Workers' Unions of Japan . [ 1 ] Like all of its predecessors, it has been affiliated with the Japanese Trade Union Confederation . In 2009, it had 158,958 members, but by 2020 this had fallen to 104,038. [ 2 ] [ 3 ] | https://en.wikipedia.org/wiki/Japan_Federation_of_Energy_and_Chemistry_Workers'_Unions |
Japan Radio Co., Ltd. ( 日本無線株式会社 , Nihon Musen Kabushiki-gaisha ) is a Japanese company specialising in the field of wireless electronics for the communications industry.
Established in 1915, the company has produced a wide variety of products including marine electronics , measuring equipment for telecommunication , radio broadcasting equipment, and amateur radio equipment, including the JST-145dx/JST-245dx HF transceivers, which were the last amateur radio transceivers produced by JRC, ending in 2002.
This article about a Japanese corporation- or company-related topic is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Japan_Radio_Company |
The Japan Society for Bioscience, Biotechnology, and Agrochemistry ( JSBBA ) is a scientific society dedicated to bioscience , biotechnology and agrochemistry , founded in 1924 as the Agricultural Chemical Society of Japan. The society took its current name in 1989.
In 1957, it was officially recognized as a society by the Ministry of Education, Science, Sports, and Culture of Japan . The current membership consists of researchers, technologists, students and private organizations in various fields of bioscience and biotechnology. [ 1 ]
This article about a chemistry organization is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Japan_Society_for_Bioscience,_Biotechnology,_and_Agrochemistry |
Japan Society for Industrial and Applied Mathematics (JSIAM) is a Japanese non-profit organization for the field of applied mathematics . JSIAM is not a branch but a Japanese counterpart of the Society for Industrial and Applied Mathematics (SIAM) based in the United States .
As same as SIAM, JSIAM publishes academic journals in Japanese and English, hold academic conferences, [ 1 ] and give awards to applied mathematicians with JSIAM membership.
The finance of JSIAM is based on membership fee and support from their corporate sponsors. Their sponsors include Canon , Nissan , NEC , NTT , Hitachi , Fujitsu and Ricoh . [ 4 ]
EASIAM (East Asia Section of SIAM) aims to advance the studies of applied mathematics in eastern Asia. As part of the Eastern Asian community, JSIAM is partially supporting EASIAM. Within their support, EASIAM is publishing the East Asian Journal of Applied Mathematics from the Global Science Press, [ 5 ] and hold the EASIAM conference every year. [ 6 ]
JSIAM has announced that they will be organizing the International Congress on Industrial and Applied Mathematics in 2023 with the Mathematical Society of Japan . [ 7 ] | https://en.wikipedia.org/wiki/Japan_Society_for_Industrial_and_Applied_Mathematics |
Japan Society of Civil Engineers ( JSCE ) ( 土木学会 , doboku gakkai ) is a professional scientific nonprofit organization of the civil engineering field of Japan . It was established as an incorporated association in 1914 and its offices are located in Yotsuya , Shinjuku , Tokyo . JSCE currently has 35,553 members. [ 2 ] | https://en.wikipedia.org/wiki/Japan_Society_of_Civil_Engineers |
Japanese Existing and New Chemical Substances (ENCS) is an inventory database for the management of existing and new chemicals primarily aimed at manufacturers of chemicals within, and importers of chemicals to Japan. [ 1 ]
This database -related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Japanese_Existing_and_New_Chemical_Substances |
The Japanese Federation of Chemical Industry Workers' Unions ( Japanese : 全国化学産業労働組合同盟 , Kagaku Domei) was a trade union representing workers in various industries in Japan.
The union was established on 16 June 1951, with the merger of unions representing chemical and general workers; rubber workers; and workers in the tyre-manufacturing industry. [ 1 ] It affiliated to the General Council of Trade Unions of Japan , and by 1958 it had 41,644 members. [ 2 ] The affiliates representing rubber workers split away in 1965, to form the National Federation of Rubber Industry Workers' Unions , [ 1 ] and as a result, by 1970 its membership had declined to 32,963. In 1972, it absorbed the All Japan Glass and Bottle Makers' Union. [ 3 ] In 1978, it merged with part of the Japanese Federation of Synthetic Chemistry Workers' Unions , to form the Japanese Federation of Chemical Workers' Unions . [ 1 ] | https://en.wikipedia.org/wiki/Japanese_Federation_of_Chemical_Industry_Workers'_Unions |
The Japanese Federation of Chemical Workers' Unions ( Japanese : 全国化学労働組合総連合 , Kagaku Soren) is a trade union representing workers in the chemical industry in Japan.
The union was founded in 1978, with the merger of the Japanese Federation of Chemical Industry Workers' Unions with part of the Japanese Federation of Synthetic Chemistry Workers' Unions . [ 1 ] Like its predecessors, it was affiliated with the General Council of Trade Unions of Japan until the late 1980s, and then with its successor, the Japanese Trade Union Confederation (RENGO). By 1996, it had 67,629 members. [ 2 ]
In 2002, the union became affiliated with the Japan Federation of Energy and Chemistry Workers' Unions (JEC), while maintaining its separate organization. [ 3 ] It moved to the right wing of the trade union movement, co-operating closely with management and, in 2016 it withdrew from both the JEC and from RENGO, objecting to their support for the Democratic Party of Japan . [ 4 ] By 2021, it had only 4,791 members in five affiliated company unions. [ 1 ] | https://en.wikipedia.org/wiki/Japanese_Federation_of_Chemical_Workers'_Unions |
The Japanese Federation of Chemical and General Workers' Unions ( Japanese : 全国化学一般労働組合同盟 ; Zenka Domei) was a trade union representing workers in various industries, especially the chemical industry, in Japan.
The union was established in 1951, [ 1 ] affiliated with the Japanese Federation of Labour , and later, with the Japanese Confederation of Labour . [ 2 ] In 1958, it had 31,801 members, [ 3 ] growing to 88,233 by 1967. [ 4 ] It was later a founding affiliate of the Japanese Trade Union Confederation . In 1995, it merged with the National Federation of General Workers' Unions to form the Japanese Federation of Chemical, Service and General Trade Unions . [ 5 ] | https://en.wikipedia.org/wiki/Japanese_Federation_of_Chemical_and_General_Workers'_Unions |
The Japanese Federation of Chemistry Workers' Unions (Kagaku League) was a trade union representing workers in the chemical and pharmaceutical industries in Japan.
The union was established in 1998, when the Japanese Federation of Synthetic Chemistry Workers' Unions merged with the All Japan Chemistry Workers' Union . Like both its predecessors, it became affiliated with the Japanese Trade Union Confederation . [ 1 ] By 2002, it had 104,000 members. [ 2 ] That year, it merged with the National Organization of All Chemical Workers , the Japan Confederation of Petroleum Industry Workers' Unions , and the National Federation of Cement Workers' Unions of Japan to form the Japan Federation of Energy and Chemistry Workers' Unions . [ 3 ] | https://en.wikipedia.org/wiki/Japanese_Federation_of_Chemistry_Workers'_Unions |
The Japanese Federation of Synthetic Chemistry Workers' Unions ( Japanese : 合成化学産業労働組合連合 , Gokaroren) was a trade union representing workers in the chemical industry in Japan.
The union was founded in 1950, with the merger of two unions representing ammonium sulfate and phosphate workers. [ 1 ] The same year, it was a founding affiliate of the General Council of Trade Unions of Japan (Sohyo). [ 2 ] From 1953 until 1957, it was chaired by Ōta Kaoru . [ 3 ] By 1967, it had 121,324 members. [ 4 ]
The union was affiliated with the Japanese Trade Union Confederation from the late 1980s, and by 1996, it had 91,242 members. [ 5 ] The All Japan Chemistry Workers' Union split away in 1987, but merged with Goka Roren in 1998 to form the Japanese Federation of Chemistry Workers' Unions . [ 6 ] [ 7 ] | https://en.wikipedia.org/wiki/Japanese_Federation_of_Synthetic_Chemistry_Workers'_Unions |
The Japanese Red List ( レッドリスト , reddo risuto ) is the Japanese domestic counterpart to the IUCN Red List of Threatened Species. The national Red List is compiled and maintained by the Ministry of the Environment , alongside a separate Red List for marine organisms. Similarly drawing on the relevant scientific authorities, NGOs, and local governments, the Ministry of the Environment also prepares and publishes a Red Data Book ( レッドドデータブック , reddo dēta bukku ) that provides further information on species and habitats . [ 3 ] [ 4 ]
The first Red List was published by the then Environmental Agency as part of the first Red Data Book in 1991; in 2020, the fifth edition of the fourth version of the Red List was published. [ 2 ] [ 5 ] In line with the Marine Biodiversity Conservation Strategy, decided upon by the Ministry in 2011, in 2017 the first Marine Life Red List was published, excluding species subject to international agreements, such as those within the remit of the Western and Central Pacific Fisheries Commission (WCPFC) ( e.g. , Pacific bluefin tuna ) and International Whaling Commission (IWC), species under evaluation by the Fisheries Agency , smaller Cetaceans , and those already evaluated for the Red List. [ 6 ]
With the renewed focus on evaluating the rarity or otherwise of marine life in line with the National Biodiversity Strategy 2012–2020, using the same evaluation criteria and categories as the Ministry of the Environment, and working in collaboration with the Ministry, the Fisheries Agency has also produced a Red List of marine resources and smaller Cetaceans , excluding species subject to international agreements, such as those in the remit of the WCPFC and IWC. [ 7 ] Evaluations of 94 species were published in 2017, all falling outside the rankings ( i.e. , being of Least Concern ), other than Pleuronichthys japonicus (Data Deficient). [ 2 ] [ 7 ]
The Red List (and Red Data Book) itself has no legal force but is intended to be used to provide information and to serve as a "warning to society". [ 3 ] Appropriate action may be taken under the 1992 Conservation of Endangered Species of Wild Fauna and Flora Act [ja] . [ 6 ]
As of the 2020 edition, thirteen taxa are used for classification purposes by the Ministry of the Environment: [ 3 ] [ 8 ]
Five further taxa are used for the Marine Life Red List: [ 3 ] [ 6 ]
The following categories are used to indicate organisms' conservation status specifically within Japan; where a species or subspecies is endemic , the status EX ( Extinct ) is indicative of its global status. [ 3 ]
Localized Red Lists and Red Data are also prepared and published by a number of Prefectural Governments , including those of Hokkaidō [ 11 ] and Okinawa . [ 12 ] | https://en.wikipedia.org/wiki/Japanese_Red_List |
In relation to the Japanese language and computers many adaptation issues arise, some unique to Japanese and others common to languages which have a very large number of characters. The number of characters needed in order to write in English is quite small, and thus it is possible to use only one byte (2 8 =256 possible values) to encode each English character. However, the number of characters in Japanese is many more than 256 and thus cannot be encoded using a single byte - Japanese is thus encoded using two or more bytes, in a so-called "double byte" or "multi-byte" encoding. Problems that arise relate to transliteration and romanization , character encoding, and input of Japanese text.
There are several standard methods to encode Japanese characters for use on a computer, including JIS , Shift-JIS , EUC , and Unicode . While mapping the set of kana is a simple matter, kanji has proven more difficult. Despite efforts, none of the encoding schemes have become the de facto standard, and multiple encoding standards were in use by the 2000s. As of 2017, the share of UTF-8 traffic on the Internet has expanded to over 90% worldwide, and only 1.2% was for using Shift-JIS and EUC. Yet, a few popular websites including 2channel and kakaku.com are still using Shift-JIS. [ 1 ]
Until 2000s, most Japanese emails were in ISO-2022-JP ("JIS encoding") and web pages in Shift-JIS and mobile phones in Japan usually used some form of Extended Unix Code . [ 2 ] If a program fails to determine the encoding scheme employed, it can cause mojibake ( 文字化け , "misconverted garbled/garbage characters", literally "transformed characters") and thus unreadable text on computers.
The first encoding to become widely used was JIS X 0201 , which is a single-byte encoding that only covers standard 7-bit ASCII characters with half-width katakana extensions. This was widely used in systems that were neither powerful enough nor had the storage to handle kanji (including old embedded equipment such as cash registers) because Kana-Kanji conversion required a complicated process, and output in kanji required much memory and high resolution. This means that only katakana, not kanji, was supported using this technique. Some embedded displays still have this limitation.
The development of kanji encodings was the beginning of the split. Shift JIS supports kanji and was developed to be completely backward compatible with JIS X 0201 , and thus is in much embedded electronic equipment. However, Shift JIS has the unfortunate property that it often breaks any parser (software that reads the coded text) that is not specifically designed to handle it.
For example, some Shift-JIS characters include a backslash (0x5C "\") in the second byte, which is used as an escape character in many programming languages.
A parser lacking support for Shift JIS will recognize 0x5C 0x82 as an invalid escape sequence, and remove it. [ 3 ] Therefore, the phrase cause mojibake.
This can happen for example in the C programming language, when having Shift-JIS in text strings. It does not happen in HTML since ASCII 0x00–0x3F (which includes ", %, & and some other used escape characters and string separators) do not appear as second byte in Shift-JIS, and backslash is not an escape characters there. But it can happen for JavaScript which can be embedded in HTML pages.
EUC , on the other hand, is handled much better by parsers that have been written for 7-bit ASCII (and thus EUC encodings are used on UNIX, where much of the file-handling code was historically only written for English encodings). But EUC is not backwards compatible with JIS X 0201, the first main Japanese encoding. Further complications arise because the original Internet e-mail standards only support 7-bit transfer protocols. Thus RFC 1468 (" ISO-2022-JP ", often simply called JIS encoding ) was developed for sending and receiving e-mails.
In character set standards such as JIS , not all required characters are included, so gaiji ( 外字 "external characters") are sometimes used to supplement the character set. Gaiji may come in the form of external font packs, where normal characters have been replaced with new characters, or the new characters have been added to unused character positions. However, gaiji are not practical in Internet environments since the font set must be transferred with text to use the gaiji. As a result, such characters are written with similar or simpler characters in place, or the text may need to be encoded using a larger character set (such as Unicode) that supports the required character. [ 4 ]
Unicode was intended to solve all encoding problems over all languages. The UTF-8 encoding used to encode Unicode in web pages does not have the disadvantages that Shift-JIS has. Unicode is supported by international software, and it eliminates the need for gaiji. There are still controversies, however. For Japanese, the kanji characters have been unified with Chinese; that is, a character considered to be the same in both Japanese and Chinese is given a single number, even if the appearance is actually somewhat different, with the precise appearance left to the use of a locale-appropriate font. This process, called Han unification , has caused controversy. [ citation needed ] The previous encodings in Japan, Taiwan Area , Mainland China and Korea have only handled one language and Unicode should handle all. The handling of Kanji/Chinese have however been designed by a committee composed of representatives from all four countries/areas. [ citation needed ]
Written Japanese uses several different scripts: kanji (Chinese characters), 2 sets of kana (phonetic syllabaries) and roman letters. While kana and roman letters can be typed directly into a computer, entering kanji is a more complicated process as there are far more kanji than there are keys on most keyboards. To input kanji on modern computers, the reading of kanji is usually entered first, then an input method editor (IME), also sometimes known as a front-end processor, shows a list of candidate kanji that are a phonetic match, and allows the user to choose the correct kanji. More-advanced IMEs work not by word but by phrase, thus increasing the likelihood of getting the desired characters as the first option presented. Kanji readings inputs can be either via romanization ( rōmaji nyūryoku, ローマ字入力 ) or direct kana input ( kana nyūryoku, かな入力 ). Romaji input is more common on PCs and other full-size keyboards (although direct input is also widely supported), whereas direct kana input is typically used on mobile phones and similar devices – each of the 10 digits (1–9,0) corresponds to one of the 10 columns in the gojūon table of kana, and multiple presses select the row.
There are two main systems for the romanization of Japanese, known as Kunrei-shiki and Hepburn ; in practice, "keyboard romaji" (also known as wāpuro rōmaji or "word processor romaji") generally allows a loose combination of both. IME implementations may even handle keys for letters unused in any romanization scheme, such as L , converting them to the most appropriate equivalent. With kana input, each key on the keyboard directly corresponds to one kana. The JIS keyboard system is the national standard, but there are alternatives, like the thumb-shift keyboard , commonly used among professional typists.
Japanese can be written in two directions . Yokogaki style writes left-to-right, top-to-bottom, as with English. Tategaki style writes first top-to-bottom, and then moves right-to-left.
To compete with Ichitaro , Microsoft provided several updates for early Japanese versions of Microsoft Word including support for downward text, such as Word 5.0 Power Up Kit and Word 98. [ 5 ] [ 6 ]
QuarkXPress was the most popular DTP software in Japan in 1990s, even it had a long development cycle. However, due to lacking support for downward text, it was surpassed by Adobe InDesign which had strong support for downward text through several updates. [ 7 ] [ 8 ]
At present, [ when? ] handling of downward text is incomplete. For example, HTML has no support for tategaki and Japanese users must use HTML tables to simulate it. However, CSS level 3 includes a property " writing-mode " which can render tategaki when given the value " vertical-rl " (i.e. top to bottom, right to left). Word processors and DTP software have more complete support for it.
The lack of proper Japanese character support on computers limited the influence of large American firms in the Japanese market during the 1980s. Japan, which had been the world's second largest market for computers after the United States at the time, was dominated by domestic hardware and software makers such as NEC and Fujitsu . [ 9 ] [ 10 ] Microsoft Windows 3.1 offered improved Japanese language support which played a part in reducing the grip of domestic PC makers throughout the 1990s. [ 11 ] | https://en.wikipedia.org/wiki/Japanese_language_and_computers |
Japaridze's polymodal logic ( GLP ) is a system of provability logic with infinitely many provability modalities . This system has played an important role
in some applications of provability algebras in proof theory , and has been extensively studied since the late 1980s. It is named after Giorgi Japaridze .
The language of GLP extends that of the language of classical propositional logic by including the infinite series [0],[1],[2],... of necessity operators. Their dual possibility operators <0>,<1>,<2>,... are defined by < n > p = ¬[ n ]¬ p .
The axioms of GLP are all classical tautologies and all formulas of one of the following forms:
And the rules of inference are:
Consider a sufficiently strong first-order theory T such as Peano Arithmetic PA .
Define the series T 0 , T 1 , T 2 ,... of theories as follows:
For each n , let Pr n ( x ) be a natural arithmetization of the predicate " x is the Gödel number of a sentence provable in T n " .
A realization is a function * that sends each nonlogical atom a of
the language of GLP to a sentence a * of the language of T . It extends to all formulas
of the language of GLP by stipulating that * commutes with the Boolean connectives, and
that ([ n ] F )* is Pr n (' F *') , where ' F *' stands for (the numeral for) the Gödel number of F * .
An arithmetical completeness theorem [ 1 ] for GLP states that a formula F is provable in GLP if and only if, for every interpretation * , the sentence F * is provable in T .
The above understanding of the series T 0 , T 1 , T 2 ,... of theories is not the only natural understanding yielding the soundness and completeness of GLP. For instance, each theory T n can be understood as T augmented with all true Π n sentences as additional axioms. George Boolos showed [ 2 ] that GLP remains sound and complete with analysis ( second-order arithmetic ) in the role of the base theory T .
GLP has been shown [ 1 ] to be incomplete with respect to any class of Kripke frames .
A natural topological semantics of GLP interprets modalities as derivative operators of a polytopological space . Such spaces are called
GLP-spaces whenever they satisfy all the axioms of GLP. GLP is complete with respect to the class of all GLP-spaces. [ 3 ]
The problem of being a theorem of GLP is PSPACE-complete . So is the same problem restricted to only variable-free formulas of GLP. [ 4 ]
GLP, under the name GP, was introduced by Giorgi Japaridze in his PhD thesis "Modal Logical Means of Investigating Provability" ( Moscow State University , 1986) and published two years later [ 1 ] along with (a) the completeness theorem for GLP with respect to its provability interpretation (Beklemishev subsequently came up with a simpler proof of the same theorem [ 5 ] ) and (b) a proof that Kripke frames for GLP do not exist. Beklemishev also conducted a more extensive study of Kripke models for GLP. [ 6 ] Topological models for GLP were studied by Beklemishev, Bezhanishvili, Icard and Gabelaia. [ 3 ] [ 7 ] The decidability of GLP in polynomial space was proven by I. Shapirovsky, [ 8 ] and the PSPACE-hardness of its variable-free fragment was proven by F. Pakhomov. [ 4 ] Among the most notable applications of GLP has been its use in proof-theoretically analyzing Peano arithmetic , elaborating a canonical way for recovering ordinal notation up to ɛ 0 from the corresponding algebra, and constructing simple combinatorial independent statements (Beklemishev [ 9 ] ).
An extensive survey of GLP in the context of provability logics in general was given by George Boolos in his book The Logic of Provability . [ 10 ] | https://en.wikipedia.org/wiki/Japaridze's_polymodal_logic |
The Japp–Klingemann reaction is a chemical reaction used to synthesize hydrazones from β-keto-acids (or β-keto-esters) and aryl diazonium salts . [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] The reaction is named after the chemists Francis Robert Japp and Felix Klingemann .
The hydrazone products of the Japp–Klingemann reaction are most often used as intermediates in syntheses of more complex organic molecules. For example, a phenylhydrazone product can be heated in the presence of strong acid to produce an indole via the Fischer indole synthesis . [ 7 ] [ 8 ]
If there is a leaving group elsewhere in the Japp–Klingemann product, the hydrazone instead can cyclize at that site via a substitution reaction to give a pyrazole . This process is a key part of the synthesis of pyraclofos [ de ] and related compounds: [ 9 ]
To illustrate the mechanism, the Japp-Klingemann ester variation will be considered. The first step is the deprotonation of the β-keto-ester. The nucleophilic addition of the enolate anion 2 to the diazonium salt produces the azo compound 3 . Intermediate 3 has been isolated in rare cases. However, in most cases, the hydrolysis of intermediate 3 produces a tetrahedral intermediate 4 , which quickly decomposes to release the carboxylic acid 6 . After hydrogen exchange, the final hydrazone 7 is produced. | https://en.wikipedia.org/wiki/Japp–Klingemann_reaction |
The Japp–Maitland condensation is an organic reaction and a type of Aldol reaction and a tandem reaction . In a reaction between the ketone 3-pentanone and the aldehyde benzaldehyde catalyzed by base the bis Aldol adduct is formed first. The second step is a ring-closing reaction when one hydroxyl group displaces the other in a nucleophilic substitution forming an oxo- tetrahydropyran .
The reaction was first described by Francis Robert Japp and William Maitland in 1904. [ 1 ]
The Japp–Maitland reaction is of some importance to synthetic organic chemistry for example as part of the synthesis of biomolecule centrolobine : [ 2 ] [ 3 ] | https://en.wikipedia.org/wiki/Japp–Maitland_condensation |
Jared C. Roach is an American biologist who invented the pairwise end sequencing strategy while a graduate student at the University of Washington . [ 1 ] [ 2 ] [ 3 ] [ 4 ]
Roach attended Cornell University , where he received his Bachelor of Science in biology in 1990. He then attended the University of Washington , where he received his PhD in immunology in 1998, and his MD in 1999. He trained in internal medicine at the University of Utah through 2001. [ 5 ]
Starting as a graduate student in the 1990s, Roach worked on the Human Genome Project from its early days through its conclusion in 2003. [ 4 ] [ 6 ] He invented pairwise end-sequencing while a graduate student in Leroy Hood 's laboratory. [ 4 ] [ 7 ] [ 3 ]
Roach was a senior fellow at the department of molecular biotechnology at the University of Washington from 1999 to 2000. In 2001, he became a research scientist at the Institute for Systems Biology . [ 8 ]
In 2009, Roach was first author on a project which sequenced the whole genomes of a family of four, including two children affected by Miller syndrome and primary ciliary dyskinesia . [ 9 ] [ 10 ] This effort identified the cause of Miller syndrome, a simple recessive Mendelian disorder . [ 11 ] It also produced the first complete whole-chromosomal parental haplotypes in humans. [ 5 ] Parental haplotyping is the process of assigning all the variants in the genome to paternal and maternal chromosomes. [ 12 ] The team applied these techniques to identify genetic mutations related to several genetic diseases , including genes for Adams–Oliver syndrome , alternating hemiplegia of childhood , certain subtypes of epilepsy , palmoplantar keratoderma , and Fanconi anemia . [ 13 ] [ 14 ] [ 15 ] [ 16 ] [ 17 ]
From 2007 to 2009, he was scientific director of the High-Throughput Analysis Core (HAC) laboratory at Seattle Children's Hospital . Since 2009, he has been a senior research scientist at the Institute for Systems Biology . Roach's group currently applies systems biology to complex genetic diseases, including Alzheimer's disease . [ 18 ] [ 19 ]
In 2020, Roach was involved in a project to map out the molecular phylogenetics of Washington state's initial SARS-CoV-2 outbreak. [ 20 ] [ 21 ] [ 22 ]
Roach has authored more than 70 publications with over 9000 citations. [ 23 ] [ 24 ] | https://en.wikipedia.org/wiki/Jared_Roach |
The Jarman–Bell principle is a concept in ecology that the food quality of a herbivore 's intake decreases as the size of the herbivore increases, but the amount of such food increases to counteract the low quality foods. [ 1 ] [ 2 ] [ 3 ] It operates by observing the allometric (non- linear scaling) properties of herbivores. [ 2 ] [ 3 ] The principle was coined by P.J Jarman (1968. [ 4 ] ) and R.H.V Bell (1971 [ 5 ] ). [ 6 ]
Large herbivores can subsist on low quality food. [ 3 ] [ 7 ] Their gut size is larger than smaller herbivores. [ 2 ] The increased size allows for better digestive efficiency, and thus allow viable consumption of low quality food. [ 8 ] Small herbivores require more energy per unit of body mass compared to large herbivores. [ 6 ] [ 8 ] A smaller size, thus smaller gut size and lower efficiency, imply that these animals need to select high quality food to function. [ 6 ] Their small gut limits the amount of space for food, so they eat low quantities of high quality diet. [ 9 ] Some animals practice coprophagy , where they ingest fecal matter to recycle untapped/undigested nutrients. [ 8 ]
However, the Jarman–Bell principle is not without exception. [ 3 ] Small herbivorous members of mammals, birds and reptiles were observed to be inconsistent with the trend of small body mass being linked with high-quality food. [ 9 ] There have also been disputes over the mechanism behind the Jarman–Bell principle; that larger body sizes does not increase digestive efficiency. [ 10 ]
The implications of larger herbivores ably subsisting on poor quality food compared to smaller herbivores mean that the Jarman–Bell principle may contribute evidence for Cope's rule . [ 3 ] [ 11 ] Furthermore, the Jarman–Bell principle is also important by providing evidence for the ecological framework of "resource partitioning, competition, habitat use and species packing in environments" [ 3 ] and has been applied in several studies.
Allometry refers to the non-linear scaling factor of one variable with respect to another. The relationship between such variables is expressed as a power law , where the exponent is a value not equal to 1 (thereby implying a non-linear relationship). [ 9 ]
Allometric relationships can be mathematically expressed as follow:
y = a B M b , b ≠ 1 {\displaystyle y=aBM^{b},b\neq 1} [ 9 ] (BM = body mass)
Kleiber's law describes how larger animals use less energy relative to small animals. Max Kleiber developed a formula that estimates this phenomenon (the exact values are not always consistent). [ 12 ]
M R = 70 ∗ W 0.75 {\displaystyle MR=70*W^{0.75}} [ 8 ] Where MR = metabolic rate (kcal/day), W = weight/body mass (Kg)
Gut capacity scales linearly with body size (gut capacity = BM 1.0 ) but maintenance metabolism (energy required to maintain homeostasis ) scales fractionally ( = BM 0.75 ). [ 8 ] Both of these factors are linked through the MR/GC (metabolic requirement to gut capacity ratio). [ 8 ] If body mass increases, then the observed ratio demonstrates how large bodies display a lower MR/GC ratio relative to a small body. [ 8 ] That is, smaller herbivores require more metabolic energy per unit of body mass than a large one. [ 8 ]
The allometric scaling of retention time (the time that food remains inside the digestive system [ 13 ] ) with respect to body mass:
T r = 7.67 ∗ D ∗ W 0.346 {\displaystyle T_{r}=7.67*D*W^{0.346}} [ 8 ] Where T r = retention time (hours), D = digestibility of the food, W = weight/body mass (Kg).
This formula was refined from a previous iteration because the previous formula took into account the entire gut, rather than focusing on the fermentation site where cellulose (the fibrous substance) is broken down. [ 8 ]
The energy gained food depends on the rate of digestion, retention time and the digestible content of the food. [ 8 ]
As herbivores , food intake is achieved through three main steps: ingestion , digestion , and absorption . [ 14 ]
Plant- based food is hard to digest [ 15 ] and is done so with the help of symbiotic microbes in the gut of the herbivore. [ 14 ] [ 15 ] When food is passed through the digestive system (including multiple stomach chambers), it breaks down further through symbiotic microbes [ 14 ] [ 16 ] at fermentation site(s).
There exists different types of stomach plans: [ 17 ]
In order, the stomach plans represent the general level of efficiency when digesting plant-based food; ruminants are better compared to pseudoruminants and monogastrics. [ 8 ] The development of the rumen not only allows a site for fermentation but also decrease the food digestion (increase retention time). [ 8 ] However, a body mass ranging from 600 to 1200 kg is enough to cause sufficient digestion regardless of stomach plan. [ 8 ]
The Jarman–Bell Principle implies that the food quality a herbivore consumes is inversely proportional to the size of the herbivore, but the quantity of such food is proportional. [ 6 ] The principle relies on the allometric (non-linear) scaling of size and energy requirement.
The metabolic rate per unit of body mass of large animals is slow enough to subside on a consistent flow of low-quality food. [ 1 ] However, in small animals, the rate is higher and they cannot draw sufficient energy from low-quality food to live on. [ 1 ]
The length of the digestive tract scales proportionally to the size of the animal. [ 8 ] A longer digestive tract allows for more retention time and hence increases the efficiency of digestion and absorption. [ 8 ]
Poorer quality food selects animals to grow larger in size, and hence develop an increased digestive efficiency compared to smaller animals. [ 6 ] Larger sized animals have a larger/longer digestive tract, allowing for more quantities of low quality food to be processed (retention time). [ 2 ] Although herbivores can consume high quality food, the relative abundance of low quality food and other ecological factors such as resource competition and predator presence influence foraging behavior of the animal [ 18 ] [ 19 ] to primarily consume low quality food. Other factors include the size of the mouth constraining the selective ability of foraging, and the absolute energy large animals require compared to small (though smaller animals require higher energy per unit body mass). [ 20 ]
Smaller animals have a limited digestive tract relative to larger animals. As such, they have a shorter retention time of food and cannot digest and absorb food to the same degree as larger animals. [ 2 ] To counteract this disadvantage, high-quality food is selected, with quantity being limited by the animals gut size. Another method to counteract this is to practice coprophagy , where re-ingestion of fecal matter recycles untapped/undigested nutrients. [ 8 ]
However, there are also reports of larger animals, including primates and horses (under dietary restrictions), practicing coprophagy. [ 8 ]
Through the extra flexibility of subsisting on low-quality food, the Jarman–Bell Principle suggests an evolutionary advantage of larger animals and hence provides evidence for Cope's rule. [ 3 ]
The Jarman–Bell Principle has some notable exceptions. [ 3 ] Small herbivorous members of class Mammalia , Aves and Reptilia were observed to be inconsistent with the trend of small body mass being linked with high quality food. [ 9 ] This discrepancy could be due to ecological factors which apply pressure and encourage an adaptive approach to the given environment, rather than taking on an optimal form of digestive physiology. [ 9 ]
Small rodents subjected to low quality diet were observed to increase food intake and increase the size of their cecum and intestine, counteracting their low quality diet by allowing viable consumption of such food and hence refuting the link between diet quality and body size. [ 21 ] [ 22 ]
Although the pattern of low food quality and body size appears consistent across multiple species, the explanation behind the principle (bigger size allowed better digestion via more retention time) has been disputed. [ 3 ] [ 10 ] [ 20 ]
M. Clauss et al. argues that retention time is not proportional to body mass above 500 grams. [ 10 ] That is, smaller species (that are above 500 grams but not too large) have been observed to rival larger species in their mean retention time.
Retention time being proportional to food intake was only observed in non-ruminant animals, not ruminants. Clauss et al. [ 10 ] suggests that this is due to the diverse adaptations that support the rumen such that the digestive efficiency of ruminants remain consistent and independent of body size and food intake. [ 10 ]
In addition to providing evidence for ecological frameworks such as "resource partitioning, competition, habitat use and species packing in environment" and Cope's rule, [ 3 ] [ 11 ] the Jarman–Bell Principle has been applied to model primate behaviours and explain sexual segregation in ungulates .
Sexual segregation in Soay sheep ( Ovis aries ) has been observed. [ 7 ] Soay sheep are polygynous in nature; males have multiple partners (opposed to polygynandry ). Two main hypotheses have been proposed to explain the observed phenomena. [ 7 ]
Male soay sheep are morphologically larger than females . Larger overall size implies larger gut size, and hence digestive efficiency. As males are larger they can subsist on lower quality food. This leads to resource partitioning of males and females and thus sexual segregation on an intraspecies level. [ 7 ]
The time taken to process food depends on the food quality; poorer/high fibre food requires more time to process and ruminate. [ 7 ] This extra time influences behaviour and, over a group of ungulates, lead to segregation via food quality. [ 7 ] Since males are larger and can handle low quality food, their feeding and ruminating activity will differ from females. [ 7 ]
Pérez-Barbería F. J., et al. (2008) tested the proposed hypothesis by feeding Soay sheep grass hay and observing the digestive efficiency between both sexes via their faecal output. [ 7 ] Given that the supplied food is the same, more faecal matter implies less digestion and thus lower digestive effectiveness. [ 7 ] Male Soay sheep produced less faecal matter than females. [ 7 ] Although this result is consistent with the Jarman–Bell principle in that it observes the relationship between size and food quality, it does not adequately explain the proposed hypotheses. [ 7 ]
For hypothesis (1), the sheep were kept in an environment where the food abundance and quality were controlled. There was no need for resources to be partitioned and segregation to occur. [ 7 ]
For hypothesis (2), there are many external factors which may influence behavioural changes in males, enough to induce sexual segregation, that are not explored in Pérez-Barbería F. J, et al. experiment. [ 7 ] In the experiment, the sheep were kept in a controlled environment with a controlled diet (monitoring for digestive efficiency only). Males consume more food than females, thereby having a greater allowance of energy to expend. [ 7 ] Activities such as predator lookout, migration or simply standing all use energy, and since males have more energy, there could be enough leeway to induce sexual segregation. [ 7 ] However, the cost:benefit ratio of segregating from a group remains equivocal and hard to test. [ 7 ]
By observing effective food digestibility in Soay sheep, the Jarman–Bell principle seems to apply at an intraspecific level. [ 7 ] The threshold at which this occurs was tested at 30%, but other studies (Ruckstuhl and Neuhaus 2002) have shown the threshold to be close to 20% [ 7 ]
Primates are very diverse in their dietary range, general morphological and physiological adaptations. [ 1 ] The Jarman–Bell principle was used to help organise these variables. [ 1 ] It expects a negative trend between body size and food quality. [ 1 ] This trend is supported by observed primate adaptations and how they help them survive in their environment. [ 1 ] It can also be used to hypothesis the general diet of newly discovered/mysterious primates that have not been researched by taking into account the animal's body size. [ 1 ] For example, information about pygmy chimpanzees was scarce around 1980s. [ 1 ] However, it was expected to have a fruity diet . [ 1 ]
Steven J. C. Gaulin examined 102 primate species (from various scientific literature) for links between size and diet, and hence the Jarman–Bell principle. [ 1 ] Omnivorous primates seemed inconsistent with the trend, likely due to the diversity of their diet. [ 1 ]
Both of the above omnivores and the majority of primate omnivores live in open ranges, particularly ecotonal regions (where two biomes meet). [ 1 ] In these environments, food abundance is comparatively lower than forest biomes. [ 1 ] The diet would shift to a mixture of low amounts of high-quality food, and high amounts of low-quality food to maximise forage and energy. [ 1 ]
Deviations from the expected trend question the universality of the principle. Steven J. C. Gaulin notes that, when the principle is applied to offer any type of explanation, it is subjected to numerous other phenomena that occur at the same time. [ 1 ] For example, the habitat range constrains the size of an organism; large primates are too heavy to live on tree tops. [ 1 ] Or perhaps the use of adaptations or even tools were enough to allow viable consumption of food quality that would not otherwise be sufficient. [ 1 ]
Extinct dinosaurs, particularly the large sauropods , can be imagined primarily through two methods. [ 9 ] Method one involves fossil records; bones and dentition . Method two involves drawing ideas from extant animals and how their body mass is linked with their diet. [ 9 ]
Reptiles generally have a shorter retention time than mammals. [ 9 ] However, this loss of digestive efficiency is offset by their ability to process food into smaller particles for digestion. [ 9 ] Smaller particles are easier to digest and ferment. [ 9 ]
As sauropods are reptiles, it would be expected that they have a similar retention time to extant reptiles. [ 9 ] However, the lack of particle reduction mechanisms (e.g. gastric mills , chewing teeth) challenges this expectation. [ 9 ] Marcus Clauss et al. hypothesised that sauropods have a very enlarged gut capacity to account for this. [ 9 ] Retention time is inversely proportional to intake amount. [ 9 ] Therefore, an enlarged gut cavity allows increased intake, and thus shorter retention time similar to other herbivorous reptiles. [ 9 ]
D. M. Wilkinson and G. D. Ruxton considered the available nutrients as a driving factor for sauropod gigantism. Sauropods appeared during the late triassic period and became extinct at the end of the cretaceous period. [ 23 ] During this time period, herbivorous plant matter such as conifers , ginkgos , cycads , ferns and horsetails may have been the dietary choice of sauropods. [ 24 ] [ 25 ] [ 26 ] These plants have a high carbon/nitrogen content. Large amounts of these plant matter would be consumed to meet the bodily nitrogen requirement. Hence, more carbon content is consumed than required. [ 24 ]
Clauss Hummel et al. (2005), cited in D. M. Wilkinson and G. D. Ruxton's paper, [ 24 ] argues that larger sizes does not necessarily improve digestive efficiency. Rather, it allows nutrient prioritisation. [ 24 ] For example, if there exists a diet with high carbon but low nitrogen content, then meeting the nitrogen dietary requirement suggests consuming a high level of carbon diet. Since gut volume scales linearly with body mass, larger animals have more capacity to digests food. | https://en.wikipedia.org/wiki/Jarman–Bell_principle |
Jaroslav Heyrovský ( Czech: [ˈjaroslav ˈɦɛjrofskiː] ⓘ ; 20 December 1890 – 27 March 1967) was a Czech chemist and inventor who received the Nobel Prize in Chemistry in 1959 for his invention of polarography . [ 2 ] [ 1 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ]
Jaroslav Heyrovský was born in Prague on December 20, 1890, the fifth child of Leopold Heyrovský, Professor of Roman Law at the Charles University in Prague , and his wife Clara, née Hanl von Kirchtreu. [ 8 ] He obtained his early education at secondary school until 1909 when he began his study of chemistry , physics , and mathematics at the Charles University in Prague. From 1910 to 1914 he continued his studies at University College London , under Professors Sir William Ramsay , W. C. McC. Lewis, and F. G. Donnan , taking his B.Sc. degree in 1913. He was particularly interested in working with Professor Donnan, on electrochemistry. [ citation needed ]
During the First World War Heyrovský worked in a military hospital as a dispensing chemist and radiologist , which enabled him to continue his studies and to take his Ph.D. degree in Prague in 1918 and D.Sc. in London in 1921.
Heyrovský started his university career as assistant to Professor B. Brauner in the Institute of Analytical Chemistry of the Charles University, Prague; he was promoted to Associate Professor in 1922 and in 1926 he became the university's first professor of physical chemistry.
Heyrovský's invention of the polarographic method dates from 1922 and he concentrated his whole further scientific activity on the development of this new branch of electrochemistry . He formed a school of Czech polarographers in the university, and was himself in the forefront of polarographic research. In 1950 Heyrovský was appointed as the Director of the newly established Polarographic Institute, which was incorporated into the Czechoslovak Academy of Sciences in 1952.
In 1926 Professor Heyrovský married Marie (Mary) Koranová, and the couple had two children, a daughter, Jitka, and a son, Michael.
Jaroslav Heyrovský died on March 27, 1967. He was interred in the Vyšehrad cemetery in Prague.
Many universities and seats of learning honored Heyrovský. He was elected Fellow of University College, London, in 1927, and received honorary doctorates from the Technical University, Dresden in 1955, the University of Warsaw in 1956, the University Aix-Marseille in 1959, and the University of Paris in 1960. He was granted honorary membership in the American Academy of Arts and Sciences in 1933; in the Hungarian Academy of Sciences in 1955; the Indian Academy of Sciences, Bangalore, in 1955; the Polish Academy of Sciences, Warsaw, in 1962; was elected Corresponding Member of the German Academy of Sciences, Berlin, in 1955; member of the German Academy of Natural Scientists, Leopoldina (Halle-Saale) in 1956; Foreign Member of the Royal Danish Academy of Sciences, Copenhagen, in 1962; Vice-President of the International Union of Physics from 1951 to 1957; President and first honorary member of the Polarographic Society, London; honorary member of the Polarographic Society of Japan; honorary member of the Chemical Societies of Czechoslovakia, Austria, Poland , England and India. In 1965, Heyrovský was elected a Foreign Member of the Royal Society (ForMemRS) in 1965 . [ 1 ]
In Czechoslovakia Heyrovský was awarded the State Prize, First Grade, in 1951, and in 1955 the Order of the Czechoslovak Republic.
Heyrovský lectured on polarography in the United States in 1933, the USSR in 1934, England in 1946, Sweden in 1947, the People's Republic of China in 1958, and in U.A.R. (Egypt) in 1960 and 1961.
The crater Heyrovský on the Moon is named in his honour. | https://en.wikipedia.org/wiki/Jaroslav_Heyrovský |
In computer science and statistics , the Jaro–Winkler similarity is a string metric measuring an edit distance between two sequences. It is a variant of the Jaro distance metric [ 1 ] (1989, Matthew A. Jaro) proposed in 1990 by William E. Winkler . [ 2 ]
The Jaro–Winkler distance uses a prefix scale p {\displaystyle p} which gives more favourable ratings to strings that match from the beginning for a set prefix length ℓ {\displaystyle \ell } .
The higher the Jaro–Winkler distance for two strings is, the less similar the strings are. The score is normalized such that 0 means an exact match and 1 means there is no similarity. The original paper actually defined the metric in terms of similarity, so the distance is defined as the inversion of that value (distance = 1 − similarity).
Although often referred to as a distance metric , the Jaro–Winkler distance is not a metric in the mathematical sense of that term because it does not obey the triangle inequality .
The Jaro similarity s i m j {\displaystyle sim_{j}} of two given strings s 1 {\displaystyle s_{1}} and s 2 {\displaystyle s_{2}} is
Where:
Jaro similarity score is 0 if the strings do not match at all, and 1 if they are an exact match. In the first step, each character of s 1 {\displaystyle s_{1}} is compared with all its matching characters in s 2 {\displaystyle s_{2}} . Two characters from s 1 {\displaystyle s_{1}} and s 2 {\displaystyle s_{2}} respectively, are considered matching only if they are the same and not farther than ⌊ max ( | s 1 | , | s 2 | ) 2 ⌋ − 1 {\displaystyle \left\lfloor {\frac {\max(|s_{1}|,|s_{2}|)}{2}}\right\rfloor -1} characters apart. For example, the following two nine character long strings, FAREMVIEL and FARMVILLE, have 8 matching characters. 'F', 'A' and 'R' are in the same position in both strings. Also 'M', 'V', 'I', 'E' and 'L' are within three (result of ⌊ max ( 9 , 9 ) 2 ⌋ − 1 {\displaystyle \lfloor {\tfrac {\max(9,9)}{2}}\rfloor -1} ) characters away. [ 3 ] If no matching characters are found then the strings are not similar and the algorithm terminates by returning Jaro similarity score 0.
If non-zero matching characters are found, the next step is to find the number of transpositions. Transposition is the number of matching characters that are not in the right order divided by two. In the above example between FAREMVIEL and FARMVILLE, 'E' and 'L' are the matching characters that are not in the right order. So the number of transposition is one.
Finally, plugging in the number of matching characters m {\displaystyle m} and number of transpositions t {\displaystyle t} the Jaro similarity of FAREMVIEL and FARMVILLE can be calculated, 1 3 ( 8 9 + 8 9 + 8 − 1 8 ) = 0.88 {\displaystyle {\frac {1}{3}}\left({\frac {8}{9}}+{\frac {8}{9}}+{\frac {8-1}{8}}\right)=0.88}
Jaro–Winkler similarity uses a prefix scale p {\displaystyle p} which gives more favorable ratings to strings that match from the beginning for a set prefix length ℓ {\displaystyle \ell } . Given two strings s 1 {\displaystyle s_{1}} and s 2 {\displaystyle s_{2}} , their Jaro–Winkler similarity s i m w {\displaystyle sim_{w}} is:
where:
The Jaro–Winkler distance d w {\displaystyle d_{w}} is defined as d w = 1 − s i m w {\displaystyle d_{w}=1-sim_{w}} .
Although often referred to as a distance metric , the Jaro–Winkler distance is not a metric in the mathematical sense of that term because it does not obey the triangle inequality . [ 4 ] The Jaro–Winkler distance also does not satisfy the identity axiom d ( x , y ) = 0 ↔ x = y {\displaystyle d(x,y)=0\leftrightarrow x=y} .
There are other popular measures of edit distance , which are calculated using a different set of allowable edit operations. For instance,
Edit distance is usually defined as a parameterizable metric calculated with a specific set of allowed edit operations, and each operation is assigned a cost (possibly infinite). This is further generalized by DNA sequence alignment algorithms such as the Smith–Waterman algorithm , which make an operation's cost depend on where it is applied. | https://en.wikipedia.org/wiki/Jaro–Winkler_distance |
The Jarzynski equality ( JE ) is an equation in statistical mechanics that relates free energy differences between two states and the irreversible work along an ensemble of trajectories joining the same states. It is named after the physicist Christopher Jarzynski (then at the University of Washington and Los Alamos National Laboratory , currently at the University of Maryland ) who derived it in 1996. [ 1 ] [ 2 ] Fundamentally, the Jarzynski equality points to the fact that the fluctuations in the work satisfy certain constraints separately from the average value of the work that occurs in some process.
In thermodynamics , the free energy difference Δ F = F B − F A {\displaystyle \Delta F=F_{B}-F_{A}} between two states A and B is connected to the work W done on the system through the inequality :
with equality holding only in the case of a quasistatic process , i.e. when one takes the system from A to B infinitely slowly (such that all intermediate states are in thermodynamic equilibrium ). In contrast to the thermodynamic statement above, the JE remains valid no matter how fast the process happens. The JE states:
Here k is the Boltzmann constant and T is the temperature of the system in the equilibrium state A or, equivalently, the temperature of the heat reservoir with which the system was thermalized before the process took place.
The over-line indicates an average over all possible realizations of an external process that takes the system from the equilibrium state A to a new, generally nonequilibrium state under the same external conditions as that of the equilibrium state B . This average over possible realizations is an average over different possible fluctuations that could occur during the process (due to Brownian motion, for example), each of which will cause a slightly different value for the work done on the system. In the limit of an infinitely slow process, the work W performed on the system in each realization is numerically the same, so the average becomes irrelevant and the Jarzynski equality reduces to the thermodynamic equality Δ F = W {\displaystyle \Delta F=W} (see above). Away from the infinitely slow limit, the average value of the work obeys Δ F ≤ W ¯ , {\displaystyle \Delta F\leq {\overline {W}},} while the distribution of the fluctuations in the work are further constrained such that e − Δ F / k T = e − W / k T ¯ . {\displaystyle e^{-\Delta F/kT}={\overline {e^{-W/kT}}}.} In this general case, W depends upon the specific initial microstate of the system, though its average can still be related to Δ F {\displaystyle \Delta F} through an application of Jensen's inequality in the JE, viz.
in accordance with the second law of thermodynamics.
The Jarzynski equality holds when the initial state is a Boltzmann distribution (e.g. the system is in equilibrium) and the system and environment can be described by a large number of degrees of freedom evolving under arbitrary Hamiltonian dynamics. The final state does not need to be in equilibrium. (For example, in the textbook case of a gas compressed by a piston, the gas is equilibrated at piston position A and compressed to piston position B ; in the Jarzynski equality, the final state of the gas does not need to be equilibrated at this new piston position).
Since its original derivation, the Jarzynski equality has been verified in a variety of contexts, ranging from experiments with biomolecules to numerical simulations. [ 3 ] The Crooks fluctuation theorem , proved two years later, leads immediately to the Jarzynski equality. Many other theoretical derivations have also appeared, lending further confidence to its generality.
Taking the log of E [ e − β W ] = e − β Δ F {\displaystyle E[e^{-\beta W}]=e^{-\beta \Delta F}} , and use the cumulant expansion up to the second cumulant, we obtain E [ W ] − Δ F ≈ 1 2 β σ W 2 {\displaystyle E[W]-\Delta F\approx {\frac {1}{2}}\beta \sigma _{W}^{2}} . The left side is the work dissipated into the heat bath, and the right side could be interpreted as the fluctuation in the work due to thermal noise.
Consider dragging an overdamped particle in a viscous fluid with temperature T {\displaystyle T} at constant force f {\displaystyle f} for a time t {\displaystyle t} . Because there is no potential energy for the particle, the change in free energy is zero, so we obtain E [ W ] = 1 2 β σ W 2 = 1 2 β f 2 σ x 2 {\displaystyle E[W]={\frac {1}{2}}\beta \sigma _{W}^{2}={\frac {1}{2}}\beta f^{2}\sigma _{x}^{2}} .
The work expended is f x {\displaystyle fx} , where x {\displaystyle x} is the total displacement during the time. The particle's displacement has a mean part due to the external dragging, and a varying part due to its own diffusion, so σ x 2 = 2 D t {\displaystyle \sigma _{x}^{2}=2Dt} , where D {\displaystyle D} is the diffusion coefficient. Together, we obtain f = k B T D E [ x ] / t {\displaystyle f={\frac {k_{B}T}{D}}E[x]/t} or γ D = k B T {\displaystyle \gamma D=k_{B}T} , where γ {\displaystyle \gamma } is the viscosity . This is the fluctuation-dissipation theorem . [ 4 ]
In fact, for most trajectories, the work is positive, but for some rare trajectories, the work is negative, and those contribute enormously to the expectation, giving us an expectation that is exactly one.
A question has been raised about who gave the earliest statement of the Jarzynski equality. For example, in 1977 the Russian physicists G.N. Bochkov and Yu. E. Kuzovlev (see Bibliography) proposed a generalized version of the fluctuation-dissipation theorem which holds in the presence of arbitrary external time-dependent forces. Despite its close similarity to the JE, the Bochkov-Kuzovlev result does not relate free energy differences to work measurements, as discussed by Jarzynski himself in 2007. [ 1 ] [ 2 ]
Another similar statement to the Jarzynski equality is the nonequilibrium partition identity , which can be traced back to Yamada and Kawasaki. (The Nonequilibrium Partition Identity is the Jarzynski equality applied to two systems whose free energy difference is zero - like straining a fluid.) However, these early statements are very limited in their application. Both Bochkov and Kuzovlev as well as Yamada and Kawasaki consider a deterministic time reversible Hamiltonian system . As Kawasaki himself noted this precludes any treatment of nonequilibrium steady states. The fact that these nonequilibrium systems heat up forever because of the lack of any thermostatting mechanism leads to divergent integrals etc. No purely Hamiltonian description is capable of treating the experiments carried out to verify the Crooks fluctuation theorem , Jarzynski equality and the fluctuation theorem . These experiments involve thermostatted systems in contact with heat baths.
For earlier results dealing with the statistics of work in adiabatic (i.e. Hamiltonian) nonequilibrium processes, see:
For a comparison of such results, see:
For an extension to relativistic Brownian motion, see: | https://en.wikipedia.org/wiki/Jarzynski_equality |
Jasna Rakonjac is a New Zealand microbiologist, and is a full professor at Massey University , specialising in the biology and structure of bacteriophages , and the development of technology for use in veterinary, medical, and agriculture fields. Rakonjac has founded two biotechnology spin-out companies.
Rakonjac was born in Serbia , and travelled to the US for a Fulbright Fellowship in New York. [ 1 ] Rakonjac completed Bachelor of Science and Master of Science degrees in molecular biology and biochemistry at the University of Belgrade , and then a PhD in biomedical sciences at the Rockefeller University . [ 2 ] [ 3 ] After postdoctoral research at Rockefeller, Rakonjac joined Plant & Food Research in New Zealand in 1990. [ 3 ] Rakonjac joined the faculty of Massey University in 2003, rising to full professor in 2023. [ 4 ]
Rakonjac specialises in the biology and structure of bacteriophages , and the development of technology for use in veterinary, medical, and agriculture fields. [ 2 ] [ 4 ] In 2003, she was awarded a Marsden grant to study bacteriophage technology, and in 2010 she was an associate investigator on a Fast Start Marsden grant led by Massey researcher Dragana Gagic, titled Stuck on you: exploring the role of adhesins in microbial symbioses . [ 1 ] [ 5 ] Rakonjac invented a new technology for the production of nanorods from bacteriophages, and is the recipient of several MBIE -funded grants to explore antibiotic resistance, develop diagnostic tests for COVID-19 and develop the nanorods production system. [ 6 ] [ 2 ] Rakonjac has founded two companies, Nanophage Technologies and Retrabac Therapeutics. Retrabac Therapeutics is developing topical antibiotic treatments for drug-resistant bacteria, [ 7 ] while Nanophage Technologies, a collaboration with BridgeWest Ventures, is developing technology for diagnostic tests and delivery of vaccines. [ 7 ] [ 3 ]
Rakonjac led the redesign of the microbiology degree at Massey. [ 2 ]
In 2019, Rakonjac was awarded the New Zealand Microbiology Society's Distinguished Orator Award. [ 8 ] [ 2 ] | https://en.wikipedia.org/wiki/Jasna_Rakonjac |
Jason Barnes (born 1989 in Guam ) is an American amputee drummer with a robotic arm . [ 1 ]
Having started out a career with a music band, in 2012 Barnes lost one of his arms in an accident. After the amputation, Barnes created his own prosthetic arm in an attempt to be able to play the drums; he was accepted into the drumming program at the Atlanta Institute of Music. [ 1 ]
Later on he started working with Gil Weinberg [ 1 ] at the Georgia Institute of Technology Institute for Robotics and Intelligent Machines to develop a cyborg arm that enables him to play his drum kit. [ 2 ]
In 2015 he took part in the Geek Picnic festival in Moscow. [ 3 ] [ 4 ] He also took part at Robotronica in Brisbane , Australia. [ 5 ]
Currently, the experience gathered around Barnes is helping create future technology for people with disabilities . [ 6 ]
This article on a United States drummer is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Jason_Barnes_(drummer) |
Jason S. Lewis is a British radiochemist whose work relates to oncologic therapy and diagnosis . His research focus is a molecular imaging-based program focused on radiopharmaceutical development as well as the study of multimodality ( PET , CT & MRI ) small- and biomolecule -based agents and their clinical translation. [ 1 ] He has worked on the development of small molecules as well as radiolabeled peptides and antibodies probing the overexpression of receptors and antigens on tumors . [ 2 ]
Jason S. Lewis was born and raised in Horndean, Hampshire, England. Lewis received his Bachelor of Science in chemistry, B.Sc. from the University of Essex in 1992. He received his Master of Science in chemistry from the University of Essex in 1993.
In 1996, he received his Doctor of Philosophy in Biochemistry at the University of Kent .
Lewis taught Radiology at the Washington University School of Medicine , Mallinckrodt Institute of Radiology from 2000 to 2008. [ citation needed ] He is the Emily Tow Jackson Chair in Oncology, the Vice Chairman for Research (Radiology) and Chief Attending of the Radiochemistry and Imaging Sciences Service at Memorial Sloan Kettering Cancer Center . He also heads a laboratory in the Sloan Kettering Institute's Molecular Pharmacology Program and is a professor at the Gerstner Sloan Kettering Graduate School of Biomedical Sciences. [ 3 ] [ 4 ]
Lewis holds joint appointments in the Departments of Radiology and the Department of Pharmacology at Weill Cornell Medical School , NY. [ citation needed ]
Lewis is a proponent of development imaging tools for use in personalized medicine . Lewis designs and develops radiochemical probes for use in nuclear medicine as well as multi-modality molecular imaging. [ 5 ] The use of these probes span from oncological metabolic detection to understanding the biological processes of cancer and pharmacological modification. These probes can be used for biomarkers in clinical trials as well as used as an agent for oncological diagnostics. [ 6 ] [ 7 ] He has developed multiple new small molecules that target tumor metabolism, as well as radiolabeled peptides and antibodies for use in probing overexpression of receptors and antigens on tumors for research, clinical trials and in the clinic. [ 8 ] | https://en.wikipedia.org/wiki/Jason_S._Lewis |
Jason X.-J. Yuan (born 1963) is an American physician scientist whose research interests center on pulmonary vascular pathobiology and pulmonary hypertension. His current research is primarily focused on the pathogenic mechanisms of pulmonary vascular diseases and right heart failure.
He was born in 1963 in Xintian County , Hunan Province, China. Yuan completed his medical training at the Suzhou Medical College in 1983, and received his doctoral degree from the Chinese Academy of Medical Sciences and Peking Union Medical College in 1993. He completed his postdoctoral fellowship at the University of Maryland School of Medicine (1988-1991).
Yuan began his academic career as a Research Assistant Professor of Medicine at the University of Maryland School of Medicine (1993-1998) where he established a translational research project using lung tissues and cells isolated from patients with idiopathic pulmonary arterial hypertension to study pathogenic mechanisms of the disease. He received a Parker B. Francis Fellowship from the Francis Families Foundation in 1994 and a Giles F. Filley Memorial Award for Excellence in Respiratory Physiology and Medicine from the American Physiological Society in 1995 for his translational research work. [ 1 ] He was also the Winner of the 1995 Cournand and Comroe Young Investigator Award of the American Heart Association. In 1998, Yuan obtained an Established Investigator Award from the American Heart Association for his pioneer work in identifying novel therapeutic approaches for pulmonary vascular disease. [ 2 ] He was recognized as one of the highly promising young investigators in the translational research field of pulmonary vascular disease and right heart failure. In 1999, Yuan moved to the University of California, San Diego and became a Professor in 2003. His research interest was then extended to study pathogenic and therapeutic mechanisms of chronic thromboembolic pulmonary hypertension, functional role of ion channels in stem cell proliferation and differentiation, and pharmacogenetics associated with idiopathic and associated pulmonary arterial hypertension. [ 3 ] While at the University of California, San Diego, he was the Vice Chair for Research of the Department of Medicine (2007-2010) and Associate Director for Research Training in the Division of Pulmonary and Critical Care Medicine (2003-2010). In July, 2010, Yuan moved to the University of Illinois at Chicago to assume a position of Program Director in the newly established Institute for Personalized Respiratory Medicine (2010-2014). He was also Vice Chair for Scholarly Activities of the Department of Medicine at the College of Medicine and Director of the Program in Pulmonary Vascular Disease and Right Heart Dysfunction at the Center for Cardiovascular Research in the University of Illinois at Chicago. [ 4 ] In May, 2010, he was appointed Associate Vice President for Translational Health Sciences of the University of Arizona . [ 5 ] At the same time, he became the founding Chief of the Division of Translational and Regenerative Medicine at the Department of Medicine of the College of Medicine. [ 6 ]
His pulmonary vascular disease research propels the field on pathogenic roles of membrane receptors and ion channels and provides a new research direction for developing therapeutic approaches for the disease. [ 7 ] He has been continuously funded by the NIH since 1993 when he received his FIRST award.
Yuan is a Fellow of the American Heart Association, the American Association for the Advancement of Science, and the American Physiological Society. He is also a Guggenheim Fellow. He is an elected Member of the American Society for Clinical Investigation and the Association of American Physicians. Yuan has served on many advisory committees and editorial boards, including Chair of the Respiratory Integrative Biology and Translational Research study section of the National Institutes of Health (NIH), and Chair of the Pulmonary Circulation Assembly of the American Thoracic Society. He is currently a regular member of the Vascular Cell and Molecular Biology study section of the NIH, Editor-in-Chief of the journal Pulmonary Circulation , and Associate Editor of the American Journal of Physiology Cell Physiology [ 8 ]
He is the leading editor of a comprehensive reference book in the field of pulmonary circulation, Textbook of Pulmonary Vascular Disease (Springer, New York, NY, 2011) and an editor or co-editor of the following books: Hypoxic Pulmonary Vasoconstriction: Cellular and Molecular Mechanisms (Kluwer Academic Publishers, Boston, MA, 2004); Ion Channels in the Pulmonary Vasculature (Taylor & Francis Group, Boca Raton, FL, 2005); Membrane Receptors, Channels, and Transporters in Pulmonary Circulation (Humana Press-Springer, New York, NY, 2010); Advances in the Management of Pulmonary Arterial Hypertension (Future Medicine, London, UK. 2013); and Lung Stem Cells in the Epithelium and Vasculature (Humana Press/Springer Cham Heidelberg New York Dordrecht London, 2015). He is a co-author (with Kim Barrett, Susan Barman and Heddwen Brooks) of Ganong’s Review of Medical Physiology (26th edition) (McGraw Hill Education/Chicago, 2019).
Yuan has received over 20 citations and awards: | https://en.wikipedia.org/wiki/Jason_X.-J._Yuan |
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