Modern concepts

Cyanine Dyes Derived from Thiazoiium Salts 3. Modern Conception... 

The Dehye-Hbckel theory of electrolytes based on the electric field surrounding each ion forms the basis for modern concepts of electrolyte behavior (16,17). The two components of the theory are the relaxation and the electrophoretic effect. Each ion has an ion atmosphere of equal opposite charge surrounding it. During movement the ion may not be exacdy in the center of its ion atmosphere, thereby producing a retarding electrical force on the ion. 

Modern concepts have been extended to the chemistry of heterocyclic compounds more slowly than to the chemistry of aromatic and aliphatic systems, but efforts are now being made to classify and explain the properties and reactions of heterocyclic compounds in terms of these newer ideas (cf. reference 11). However, many of the most important heterocyclic compounds are potentially tautomeric, and elucidation of their tautomeric composition must precede a logical treatment of their properties. Further, many natural products such as the nucleic acids and alkaloids contain potentially tautomeric groups and information of this type is needed for a detailed explanation of th reactions which they undergo,... 

Perhaps the first approach to the modern conception of the gas-turbine power plant was that described in... 

The use of mixed acid (mixt of nitric and sulfuric acids) as a nitrating agent was first described in 1846 by Muspratt Hoffman (Ref 1). The sulfuric acid in their mixt was considered to be a dehydrating agent , a view first advanced by Spindler (Ref 4) and developed further by Markovnikov (Ref 7) Sapozhnikov (Ref 8). The modern concept of the role of sulfuric acid in mixed... 

In their more familiarly written form NO(OH)2+ = H2N03+ and N(OH)3++ = H3N03++ are respectively the nitracidium and hydronitracidium ions. For further discussion of early theories of species existing in MA the reader is referred to Urbanski (Ref 74, pp 12—14). Modern concepts will be examined in detail in Section VIII... 

The present article will consist of a brief History of SP (Section II) Representative SP and their Uses (Section III) Production Methods of Representative Propellants (Section. IV) Physical Characteristics of Representative Propellants (Section V) Chemical Characteristics Performance (including modern concepts of ignition and combustion) (Section VI) Explosion Hazards (Section VII) and Brief Summaries of Recent Literature on SP (Section VIII)... 

The Bart reaction shows characteristics similar to the Sandmeyer reaction (anionic reagent, catalysis by copper). However, it has not been investigated in the light of the modern concepts applied to the elucidation of the Sandmeyer reaction (Sec. 8.6). 

Cooke, N. H. C. and Olsen, K., Some modern concepts in reversed-phase liquid chromatography on chemically bonded alkyl stationary phases,. Chromatogr. Sci., 18, 512, 1980. 

Modern Concepts in Nitrate Delivery Systems. Goldberg, A. A. J., Parsons,... 

The specific fundamental idea formulated in paper [1], which found most applications in biophysics, is the concept of incomplete equilibrium, of kinet-ically frozen degrees of freedom. This idea is at the base of modern concepts of enzyme functioning [135-137], and in many cases it is clearly formulated as one originating from the paper [1] of I.M. Lifshitz. 

V) with a reactive methylene group at C6. According to modern concepts, the phenolic hydroxyl group is believed to activate the positions ortho and para to it. In the case of kojic acid, of the three positions in question, only the one ortho position, namely at C6, is available for substitution. This activating effect of the phenolic function would be particularly marked in alkaline media, where kojic acid probably exists in the form of a phenoxide ion (LXIII) the negative charge would be shared by C6 (LXIV), where it... 

However, the majority of small scale tests actually used to measure fire properties are incapable of determining either more than a single property or combined properties. Furthermore, there is, often, no attempt to investigate whether the test results are can be related to results to be expected in full scale fires. This is incompatible, thus, with modern concepts of fire hazard. 

The theories that should feature prominently in the understanding of chemical effects have been summarized in this volume, without demonstrating their application. The way forward has been indicated by Primas [67] and in the second volume of this work the practical use of modern concepts such as spontaneous symmetry breaking, non-local interaction, bohmian mechanics, number theories and space-time topology, to elucidate chemical effects will be explored. The aim is to stimulate renewed theoretical interest in chemistry. 

Soon after the discovery of the neutron (Chadwick, 24 Feb. 1932, letter to N. Bohr), Landau improvised the concept of neutron star in discussion with Bohr (Rosenfeld, 1974). The modern conception of the neutron star origin is... 

Irving Langmuir, "Modern Concepts in Physics and Their Relation to Chemistry," Science 70 (October 25, 1929) 385396, on 390, 394. 

At the Faraday meeting, Langmuir had emphasized the necessity for chemists to explain phenomena in terms of quantum relationships, insisting "A molecule cannot dissociate by a continuous process.. . . We ought to consider these phenomena frankly as quantum phenomena." For Langmuir, it made no sense to talk of a series of frequencies "It is very difficult to get a physical conception of a mechanism which involves the product of several intensities."93 To this, Perrin replied that he meant that the reaction takes place in "steps" in response to different radiation frequencies. 94 Langmuir remained unconvinced in 1929, when he wrote in an article, "Modern Concepts in Physics and Their Relation to Chemistry,"... 

The idea of a unique Jewish physicality or Jewish blood was not new to nineteenth-century America. As James Shapiro has recently argued, theology heavily influenced early modern conceptions of both racial and national difference in Europe, and so the alien Jew figured prominently in European discussion as early as the sixteenth century. In 1590 Andrew Willet argued that Jews have never been grafted onto the stock of other... 

Marie Sklodowska Curie (1867—1934) and Pierre Curie (1859—1906) are credited with discovering polonium as they sought the source of radiation in pitchblende after they removed the uranium from its ore. Their discovery in 1898 led to the modern concepts of the nucleus of the atom, its structure, and how it reacts. 

For him, the survival of antiquity served as a touchstone for the extent to which the conflict between ancient and modern conceptions of faith had penetrated the consciousness of the age. The idea of a formal, intuitive imprint on the viewer came from Anton Springer (Foster, introduction to Warburg 6). 

The chapters in this volume illustrate how molecular concepts underlie catalysis. They illustrate how modern concepts of biology are influencing catalysis and catalyst discovery how concepts of homogeneous and surface catalysis have merged (a theme that is evident in the preceding several volumes of the Advances), exemplified by dendrimer catalysts that have properties of both molecules and surfaces and how concepts of molecular catalysis by bases have influenced the development of new solid-base catalysts and fundamental understanding of how they function. 

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