Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

The Topics

A preliminary chapter is used to outline the main building blocks and the basic construction mechanisms employed in the biosynthesis of natural products. Many of these fundamental principles [Pg.2]


A number of networks, addresses the topic of Inspection, have been established around ongoing private or Nationally funded research, such as ... [Pg.932]

Future research relevant under the topics of the ECNDT conference should also find its place under some of the Thematic Research Programmes of the 5th Framework Programme. [Pg.934]

Although the topic of this paper easily extends to other disciplines, only eddy-current inspections will be eonsidered here. Eddy-current inspections do not typically capture spatial information with the signal however, there are large benefits to be found by keeping the spatial component integrated with the eddy-current signal. First, we will explore different approaches to adding spatial data to an eddy-current inspection. [Pg.1015]

The topic of capillarity concerns interfaces that are sufficiently mobile to assume an equilibrium shape. The most common examples are meniscuses, thin films, and drops formed by liquids in air or in another liquid. Since it deals with equilibrium configurations, capillarity occupies a place in the general framework of thermodynamics in the context of the macroscopic and statistical behavior of interfaces rather than the details of their molectdar structure. In this chapter we describe the measurement of surface tension and present some fundamental results. In Chapter III we discuss the thermodynamics of liquid surfaces. [Pg.4]

The preceding material of this section has focused on the most important phenomenological equation that thermodynamics gives us for multicomponent systems—the Gibbs equation. Many other, formal thermodynamic relationships have been developed, of course. Many of these are summarized in Ref. 107. The topic is treated further in Section XVII-13, but is worthwhile to give here a few additional relationships especially applicable to solutions. [Pg.76]

The succeeding material is broadly organized according to the types of experimental quantities measured because much of the literature is so grouped. In the next chapter spread monolayers are discussed, and in later chapters the topics of adsorption from solution and of gas adsorption are considered. Irrespective of the experimental compartmentation, the conclusions as to the nature of mobile adsorbed films, that is, their structure and equations of state, will tend to be of a general validity. Thus, only a limited discussion of Gibbs monolayers has been given here, and none of such related aspects as the contact potentials of solutions or of adsorption at liquid-liquid interfaces, as it is more efficient to treat these topics later. [Pg.92]

The topic of spreading rates is of importance in the technology of the use of mono-layers for evaporation control (see Section IV-6) it is also important, in the opposite sense, in the lubrication of fine bearings, as in watches, where it is necessary that the small drop of oil remain in place and not be dissipated by spreading. Zisman and coworkers have found that spreading rates can be enhanced or reduced by the presence of small amounts of impurities in particular, strongly adsorbed surfactants can form a film over which the oil will not spread [48]. [Pg.111]

Microemulsions are treated in a separate section in this chapter. Unlike macro- or ordinary emulsions, microemulsions are generally thermodynamically stable. They constitute a distinctive type of phase, of structure unlike ordinary homogeneous bulk phases, and their study has been a source of fascination. Finally, aerosols are discussed briefly in this chapter, although the topic has major differences from those of emulsions and foams. [Pg.500]

To proceed with the topic of this section. Refs. 250 and 251 provide oversights of the application of contemporary surface science and bonding theory to catalytic situations. The development of bimetallic catalysts is discussed in Ref. 252. Finally, Weisz [253] discusses windows on reality the acceptable range of rates for a given type of catalyzed reaction is relatively narrow. The reaction becomes impractical if it is too slow, and if it is too fast, mass and heat transport problems become limiting. [Pg.729]

Students and instructors). Each chapter presents first the basic surface chemistry of the topic, with optional material in small print. Derivations are generally given in full and this core material is reinforced by means of problems at the end of the chapter. A solutions manual is available to instructors. It is assumed that students have completed the usual undergraduate year course in physical chemistry. As a text for an advanced course, the basic material is referenced to fundamental, historical sources, and to contemporary ones where new advances have been incorporated. There are numerous examples and data drawn from both the older and from current literature. [Pg.801]

There has been a general updating of the material in all the chapters the treatment of films at the liquid-air and liquid-solid interfaces has been expanded, particularly in the area of contemporary techniques and that of macromolecular films. The scanning microscopies (tunneling and atomic force) now contribute more prominently. The topic of heterogeneous catalysis has been expanded to include the well-studied case of oxidation of carbon monoxide on metals, and there is now more emphasis on the flexible surface, that is, the restructuring of surfaces when adsorption occurs. New calculational methods are discussed. [Pg.802]

For very fast reactions, as they are accessible to investigation by pico- and femtosecond laser spectroscopy, the separation of time scales into slow motion along the reaction path and fast relaxation of other degrees of freedom in most cases is no longer possible and it is necessary to consider dynamical models, which are not the topic of this section. But often the temperature, solvent or pressure dependence of reaction rate... [Pg.851]

At this point, it is instructive to discuss the distinction between molecules, anchors, and quantum mechanical wave functions that represent them. The topic is best introduced by using an example. Consider the H4 system [34]. [Pg.333]

The nonbonding electrons of the nitrogen atom are important in determining spin re-pairing, and thus the conical intersections. This is the physical origin of the topicity concept developed by Salem and co-workers [2,30]. Two different spin... [Pg.374]

Acknowledgement. It is a pleasure to thank M. Hochbruck and Ch. Lubich for their helpful comments on the topics of this paper. [Pg.409]

This book is conceived as a textbook for application in teaching and self-learning of chemoinfoimatics. We aim to present a comprehensive overview of the field of che-moinformatics for students, teachers, and scientists from other areas of chemistry, from biology, informatics, and medicine. Those interested in a more in-depth presentation and analysis of the topics in this Textbook are referred to an accompanying set of four volumes. [Pg.11]

More details on all the topics in this chapter can found in the Handbook. [Pg.161]

First, we have an initial, and probably utterly crude, dataset. Genuine data pre-processing has only just started. The task is to assess the quality of the data. One of the topics for discussion in this chapter is the methods by which one finds out the potential drawbacks of the dataset. [Pg.205]

To get to know various databases covering the topics of bibliographic data, physicochemical properties, and spectroscopic, crystallographic, biological, structural, reaction, and patent data... [Pg.227]

The initial step is to identify which database, from a few thousands worldwide (about 10 000 in 2002), provides the requested information. The next step is to determine which subsection of the topic is of interest, and to identify typical search terms or keywords (synonyms, homonyms, different languages, or abbreviations) (Table 5-1). During the search in a database, this strategy is then executed (money is charged for spending time on some chemical databases). The resulting hits may be further refined by combining keywords or database fields, respectively, with Boolean operators (Table 5-2). The final results should be saved in electronic or printed form. [Pg.230]

Proposed flux models for porous media invariably contain adjustable parameters whose values must be determined from suitably designed flow or diffusion measurements, and further measurements may be made to test the relative success of different models. This may involve extensive programs of experimentation, and the planning and interpretation of such work forms the topic of Chapter 10, However, there is in addition a relatively small number of experiments of historic importance which establish certain general features of flow and diffusion in porous media. These provide criteria which must be satisfied by any proposed flux model and are therefore of central importance in Che subject. They may be grouped into three classes. [Pg.50]

Rather than continuing to deal with abstractions, let us plunge right in by carrying out a bare bones MM calculation. After the reader has a practical sense of how MM calculations work, we shall return to some of the topics referred to above in more detail and we shall introduce some others. [Pg.100]

The real value of direct interaction between a lecturer and his audience is in the interest he can aronse by presenting the topic in a challenging and perhaps personal way as well as in the give-and-take interaction of direct exchange and participation. I have always tried in my lectnres to give my stndents not only a presentation of facts and concepts, but, based on my own experience and involvement, to convey to them the fascination of exploring the intrigning world of chemistry. [Pg.92]

A wide variety of carbocations and carbodications, including those that are aromatically stabilized as well those as stabilized by heteroatoms, were reported in the nearly 200 publications on the topic during my Cleveland years. [Pg.94]

This chapter provides only a brief discussion of relativistic calculations. Currently, there is a small body of references on these calculations in the computational chemistry literature, with relativistic core potentials comprising the largest percentage of that work. However, the topic is important both because it is essential for very heavy elements and such calculations can be expected to become more prevalent if the trend of increasing accuracy continues. [Pg.261]

Of all the topics discussed in this text, mesoscale simulations are probably at the most infantile stage of development. The idea of the mesoscale calculations is very attractive and physically reasonable. However, it is not as simple as one might expect. The choice of bead sizes and parameters is crucial to obtaining physically relevant results. More complex bead shapes are expected to be incorporated in future versions of these techniques. When using one simulation technique to derive parameters for another simulation, very small errors in a low-level calculation could result in large errors in the final stages. [Pg.275]

The modeling of biomolecules is a very broad and sophisticated field. The description given in this chapter is only meant to provide the connections between the topics in this book and this field. Before embarking on a computational biochemical study, it is recommended that the researcher investigate the literature pertaining to this field more closely. The references provided below should provide a good starting point for such a survey. [Pg.298]

Each of the following reactions has been described in the chemical literature and involves an organic starting matenal somewhat more complex than those we have encountered so far Nevertheless on the basis of the topics covered in this chapter you should be able to wnte the structure of the principal organic product of each reaction... [Pg.184]

An important concern to chemists is synthesis the challenge of preparing a particular compound m an economical way with confidence that the method chosen will lead to the desired structure In this section we will introduce the topic of synthesis emphasiz mg the need for systematic planning to decide what is the best sequence of steps to con vert a specified sfarfmg mafenal fo a desired producf (fhe target molecule)... [Pg.265]


See other pages where The Topics is mentioned: [Pg.998]    [Pg.149]    [Pg.328]    [Pg.465]    [Pg.638]    [Pg.802]    [Pg.54]    [Pg.838]    [Pg.1045]    [Pg.1217]    [Pg.1283]    [Pg.2470]    [Pg.2817]    [Pg.277]    [Pg.504]    [Pg.544]    [Pg.2]    [Pg.93]    [Pg.145]    [Pg.156]    [Pg.240]   


SEARCH



Advanced Topic The Color of Metals

Advanced Topic The Fourier Transform Spectrometer

Advanced Topics The Transition State Ensemble for Folding

Brief Analysis of the Different Chapters and their Main Topics

Drug Permeation Through the Skin and Topical Preparations

Overview of the Main Topics

Special topic 1 - Developing no-tillage systems without chemicals the best of both worlds

Special topic 5 - Voice from the other side a Ghanaian view on organics

The Rotation Barrier of Ethane and Related Topics

The topicity of enantioselective reactions

Topic 1.4. Representation of Electron Density by the Laplacian Function

Topic 2.3. The Anomeric Effect in Cyclic Compounds

Topic 4.1. The Role Carbocations and Carbonium Ions in Petroleum Processing

Topical Drugs Used in the Treatment of Skin Disorders

Topics Covered by the AP Chemistry Exam

University-industry relationships the core topics

© 2024 chempedia.info