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Mechanisms general discussion

Chemisoq)tion bonding to metal and metal oxide surfaces has been treated extensively by quantum-mechanical methods. Somoijai and Bent [153] give a general discussion of the surface chemical bond, and some specific theoretical treatments are found in Refs. 154-157 see also a review by Hoffman [158]. One approach uses the variation method (see physical chemistry textbooks) ... [Pg.714]

We first consider tlnee examples as a prelude to the general discussion of basic statistical mechanics. These are (i) non-mteracting spin-i particles in a magnetic field, (ii) non-interacting point particles in a box,... [Pg.379]

For air flow impinging normally to the surface from slots, nozzles, or perforated plates, the heat-transfer coefficient can be obtained from the data of Friedman and Mueller (Proceedings of the General Discussion on Heat Transfer, Institution of Mechanical Engineers, London, and American Society of Mechanical Engineers, New York, 1951, pp. 138-142). These investigators give... [Pg.1191]

We begin by reviewing the regulatory driving force in the United States for air pollution abatement. To appreciate the objectives of our Federal air pollution control regulations, an understanding of the fate and transport mechanisms in the environment is important. Hence, some general discussions on the behavior of pollutants in the atmosphere are included in this chapter. [Pg.1]

Golburn, A. P, Problems in Design and Research on Gon-densers of Vapours and Vapour Mixtures, James Glayton lecture, delivered Sept. 12, (1951), pub. General Discussions of Heat Transfer, The Institution of Mechanical Engineers and ASME, p. 448. [Pg.283]

The historical development of the electronic configuration model is traced and the status of the model with respect to quantum mechanics is examined. The successes and problems raised by the model are explored, particularly in chemical ah initio calculations. The relevance of these issues to whether chemistry has been reduced to quantum mechanics is discussed, as are some general notions on reduction. [Pg.18]

In Sections 42 and 43 we shall describe the accurate and reliable wave-mechanical treatments which have been given the hydrogen molecule-ion and hydrogen molecule. These treatments are necessarily rather complicated. In order to throw further light on the interactions involved in the formation of these molecules, we shall preface the accurate treatments by a discussion of various less exact treatments. The helium molecule-ion, He , will be treated in Section 44, followed in Section 45 by a general discussion of the properties of the one-electron bond, the electron-pair bond, and the three-electron bond. [Pg.208]

When an oxidation or a reduction could be considered in a previous chapter, this was done. For example, the catalytic hydrogenation of alkenes is a reduction, but it is also an addition to the C=C bond and was treated in Chapter 15. This chapter discusses only those reactions that do not fit into the nine categories of Chapters 10-18. An exception to this rule was made for reactions that involve elimination of hydrogen (19-1-19-6), which were not treated in Chapter 17 because the mechanisms generally differ from those in that chapter. [Pg.1510]

Addition of hydrogen sulfide in solution was found to enhance the rate of this process albeit the efficiencies were generally low, partly due to concomitant precipitation of elemental sulfur during the photolytic experiments. The effects of reaction temperature, light intensity, and pH of the electrolyte were studied, and the photo-catalytic mechanism was discussed with reference to the theory of charge transfer at photoexcited metal sulfide semiconductors. [Pg.270]

Research on plasma-deposited a-C(N) H films has been frequently included in the general discussion of carbon nitride solids [2, 3]. However, the presence of hydrogen in its composition, and the complexity of the deposition process, which introduces the nitrogen species in the already intricate hydrocarbon plasma-deposition mechanism, make a-C(N) H films deserve special consideration. This is the aim of the present work to review and to discuss the main results on the growth, structure, and properties of plasma-deposited a-C(N) H films. As this subject is closely related to a-C H films, a summary of the main aspects relative to the plasma deposition of a-C H films, their structure, and the relationship between the main process parameters governing film structure and properties is presented... [Pg.218]

Actually, the first attempts to use the electron density rather than the wave function for obtaining information about atomic and molecular systems are almost as old as is quantum mechanics itself and date back to the early work of Thomas, 1927 and Fermi, 1927. In the present context, their approach is of only historical interest. We therefore refrain from an in-depth discussion of the Thomas-Fermi model and restrict ourselves to a brief summary of the conclusions important to the general discussion of DFT. The reader interested in learning more about this approach is encouraged to consult the rich review literature on this subject, for example by March, 1975, 1992 or by Parr and Yang, 1989. [Pg.47]

For a general discussion of the mechanism of stress corrosion cracking see Fontana (1986). [Pg.291]

Small-scale variation of convected quantities like temperature in turbulent fluid. Part 1. General discussion and the case of small conductivity. Journal of Fluid Mechanics 5, 113-133. [Pg.407]

General Discussion—Pressure Effects and Substitution Mechanisms... [Pg.62]

General Discussion—Proton-Transfer Reaction Rates and Mechanisms... [Pg.84]

In general, there is an array of equilibrium-based mathematical models which have been used to describe adsorption on solid surfaces. These include the widely used Freundlich equation, a purely empirical model, and the Langmuir equation as discussed in the following sections. More detailed modeling approaches of sorption mechanisms are discussed in more detail in Chap. 3 of this volume. [Pg.130]

The functions of these fusion proteins and their precise roles in the induction of cancer are currently the subject of intense investigation (Collins et al., 2006 Huntly et al., 2004 Kindle et al., 2005). In general, it appears that since the proteins are fused in-frame, their catalytic domains continue to function, but these activities are mis-directed by the targeting domains of their fusion partners. The result is aberrant acetylation of chromatin and non-chromatin proteins, as well as sequestration of key nuclear regulators. These mechanisms are discussed in-depth in Chapter 8 of this book. Furthermore, two recent studies have demonstrated that wild-type MOZ is essential for development of hematopoietic stem cells (Katsumoto et al., 2006 Thomas et al., 2006). This suggests that AML may arise not only due to the aberrant activity of the fusion proteins, but also due to the loss of their original function. [Pg.306]

This chapter focuses on silica synthesis via the microemulsion-mediated alkoxide sol-gel process. The discussion begins with a brief introduction to the general principles underlying microemulsion-mediated silica synthesis. This is followed by a consideration of the main microemulsion characteristics believed to control particle formation. Included here is the influence of reactants and reaction products on the stability of the single-phase water-in-oil microemulsion region. This is an important issue since microemulsion-mediated synthesis relies on the availability of surfactant/ oil/water formulations that give stable microemulsions. Next is presented a survey of the available experimental results, with emphasis on synthesis protocols and particle characteristics. The kinetics of alkoxide hydrolysis in the microemulsion environment is then examined and its relationship to silica-particle formation mechanisms is discussed. Finally, some brief comments are offered concerning future directions of the microemulsion-based alkoxide sol-gel process for silica. [Pg.147]

The above observations clearly indicate the inadequacy of the simple second-order law for describing the reaction rate outside the conditions of strongly acidic solutions and low initial cerium(III) concentrations. A more general rate law, suggested by considerations of the reaction mechanism (see Discussion), which takes into account the inhibiting effect of cerium(III), is of the form... [Pg.239]


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General Mechanism

General discussion

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