Concepts, advanced

Lemieux and Spohr (Alberta) here trace our understanding of enzyme specificity in broad perspective as they assess Emil Fischer s lock and key concept advanced a century ago in relation to current ideas of molecular recognition. It may be noted that the very first article in Volume 1 of Advances, by Claude S. Hudson, was devoted to the Fischer cyanohydrin synthesis and the consequences of asymmetric induction. 

Using solid-state physics and physical metallurgy concepts, advanced non-destructive electronic tools can be developed to rapidly characterize material properties. Non-destructive tools operate at the electronic level, therefore assessing the electronic structure of the material and any perturbations in the structure due to crystallinity, defects, microstructural phases and their features, manufacturing and processing, and service-induced strains.1 Electronic, magnetic, and elastic properties have all been correlated to fundamental properties of materials.2 5 An analysis of the relationship of physics to properties can be found in Olson et al.1... 

The Systematic Approach. The systematic approach for deriving rate equations was first devised by Fromm based on certain concepts advanced by Volkenstein and Goldstein. Its underlying principles, however, are more akin to the graphic method of King and Altman. The procedure to be described here is a modified method that includes the contributions from the aforementioned workers and from Wong and Hanes. ... 

Heat Pulse. (Also see Detonation, Flash-Across, Heat Pulse and Hypervelocity Phenomena in Vol 4, p D348-49). A concept advanced by M.A. Cook (Refs 1 2) to provide a theoretical mechanism for the shock initiation of explosives. Cook also used the heat pulse concept in his explanation of certain unusual luminosity effects observed primarily in the detonation of liquid explosives. Briefly stated, Cook believes that detonation is initiated when as a result of rising temperature, produced by reaction in the already shocked region of an explosive, a portion of the explosive becomes thermally super-conductive and a heat-pulse flashes thru it and catches up with the shock front. Studies conducted by Kendrew Whitbread (Ref 3) tend to discount the necessity for postulating a heat-pulse in a theoretical explanation of shock initiation or the above unusual luminosity effects. More recent studies of shock initiation have also failed to produce any conclusive evidence of a heat-pulse ... 

LEWIS ELECTRON THEORY. A theory involving acid and base formation, neutralization, and related phenomena on the basis of exchange of electrons between substances and the formation of coordinate bonds. It represented an important advance in chemical theory. largely replacing earlier concepts. Advanced in 1923 by Gilbert N Lewis, it contributed much to the development of coordination chemistry- in which the base is represented by the ligand and the acid by the metal ion. 

To test the concepts advanced by Weil t al., 82 studies covering 122 compounds and 566 dose levels were collected from the literature. These studies were analyzed for effects obtained at 13 weeks and at two years. The analysis is shown in Table XII. 

The basic concepts advanced at the beginning of our discussion permit other possible routes of conversion. Scheme 56.3 depicts one of these hypotheses, which, for all its obeisance to the rules of good chemistry, is perhaps more a mental divertissement than anything else. Yet, this new sequence serves its pur-... 

Photosensitive onium salts provide the means for the development of novel positive and negative photoresists based on the concepts advanced in this paper. Work is currently proceeding both at this laboratory and in others to explore the unique opportunities for photoresists based on these materials as latent photochemical sources of strong protonic acids. 

B. Hammer, J.K. Norskov, Theoretical surface science and catalysis - calculations and concepts. Advances in Catalysis, 45(2000) 71. 

Superelectrophilic Activation or Superelectrophilic Solvation. Trifluoromethanesulfonic acid (triflic acid, TfOH) has been extensively employed as a superacid Ho= —14.1) in superelectrophilic activation (or superelectrophilic solvation), both concepts advanced by Olah. Superelectrophilic activations may occur when a cationic electrophile reacts with a Bronsted or Lewis acid to give a dicationic (doubly electron-deficient) superelectrophile. However, it should be recognized that the activation may proceed through superelectrophilic solvation without necessarily forming limiting dicationic intermediates. The frequently used depiction of protosolvated species as their limiting dications is just for simplicity. ... 

The concept advanced by Marsh and Drabkin that protein deficiency leads to hyperlipoproteinemia does not seem to apply to other protein-deficiency states such as cirrhosis of the liver (Man et al. 1945), malnutrition (Man and Gildea, 1938), kwashiorkor (Schwartz and Dean, 1957), or idiopathic hypoalbuminemia (Gordon et al, 1959). It should be pointed out, however, that the conclusions by Marsh and Drahkin were based on experiments conducted in the early stage of experimental... 

Such a complicated character of F(6/T) is clarified in the theory of heat capacity for linear polymers, established by Dole [94] and described in detail by Wunderlich and, Baur [95]. It is based on a concept advanced by Tarasov [96] and developed by Lifshitz [97] for chain solids. 

The first three strategies are considered briefly in the present article. The physical modification category is discussed in considerable detail elsewhere in this compilation, with emphasis on plasma and corona procedures. Inherent modifications, which are an integral feature of the acid/base concepts advanced in preceding section, are discussed in greater detail. 

In our opinion, the concepts advanced herein, though they need further elaboration and refinement, have the potential to accommodate much of the accumulated information about the varied regulatory effects on plant morphogenesis produced by the several phytohormones and by some other morphogenically active substances. 

Element 94 was named plutonium after the planet discovered last, Pluto. In 1941, the first 0.5 /rg of the fissionable isotope Pu were produced by irradiating 1.2 kg of uranyl nitrate with cyclotron-generated neutrons. In 1948, trace amounts of Pu were found in nature, formed by neutron capture in uranium. In chemical studies, plutonium was shown to have properties similar to uranium and not to osmium as suggested earlier. The actinide concept advanced by G. T. Seaborg, to consider the actinide elements as a second / transition series analogous to the lanthanides, systematized the chemistry of the transuranium elements and facilitated the search for heavier actinide elements. The actinide elements americium (95) through fermium (100) were produced first either via neutron or helium-ion bombardments of actinide targets in the years between 1944 and 1955. 

It is possible to account for these features by extending the atomic liquid theory described above. This account has been checked in recent simulation work which provides detailed corroboration for the concepts advanced here. 

IX-1] KITAMURA, H., et al., ABWR-II Development The economically competitive 1700 MW(e) BWR with large bundle concept. Advanced Nuclear Power Plants (Proc. Int. Congress, Cordoba, Spain May 4-7, 2003), ICAPP 03, No. 3119 (2003). 

Nowakowski, T, Werbihska-Wojciechowska, S. (2012). Developments of time dependencies modeling concepts, Advances in safety, reliability and risk management. Proc. of the European Safety and Reliability Conference, ESREL 2011, Troyes, France, 18-22 September 2011. eds. B6renguer Ch., Grail A., Guedes Soares C., Leiden CRC Press/Balkema 832-838. 

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