Surveys Critical

Crowther, J. (1997). Soil phosphate surveys critical approaches to sampling, analysis and interpretation. Archaeological Prospection 4 93-102. 

This chapter summarizes important data for intrinsic viscosity and translational friction coefficient of polypeptides. The first half of the chapter discusses the data obtained in helicogenic solvents and in helix-breaking solvents. It is actually a supplement to the review article by Benoit et al. (61), in which such data published by 1967 were surveyed critically. The second half of the chapter is concerned with the helix-coil transition region. The context here is largely descriptive because of the lack of relevant theory. 

This chapter will attempt to survey critically the major areas of experimentally determined kinetic data which are available on polycondensation reactions and their mechanisms, and to emphasize the mechanistic similarities of many of the reactions. The statistics of polycondensation reactions will be touched on only to the extent that it helps understand the reactions and their kinetics. The general approach to the subject of kinetics is designed to be of primary use and interest to those polymer chemists who are concerned with the synthesis of products having desired properties, and with the understanding of their synthetic processes. 

When minute amounts of polymer cause significant changes in a flow, the key fluid property thought to be associated with the effect is extensional viscosity. Consequently, there is considerable interest in this non-Newtonian property and current research activity is devoted to devising means of measuring the property and to understanding its origins at the microscopic level. To help focus on this property, this survey critically examines the evidence which links extensional viscosity to the observed effects, and reviews the techniques which are used to measure the property. 

This chapter introduces the experimental work described in the following chapters. Some mechanistic aspects of the Diels-Alder reaction and Lewis-acid catalysis thereof are discussed. This chapter presents a critical survey of the literature on solvent ejfects on Diels-Alder reactions, with particular emphasis on the intriguing properties of water in connection with their effect on rate and selectivity. Similarly, the ejfects of water on Lewis acid - Lewis base interactions are discussed. Finally the aims of this thesis are outlined. 

In Chapter 6 we survey what has been accomplished and indicate directions for future research. Furthermore, we critically review the influence of water on Lewis acid - Lewis base interactions. This influence has severe implications for catalysis, in particular when hard Lewis acids and bases are involved. We conclude that claims of Lewis-acid catalysis should be accompanied by evidence for a direct interaction between catalyst and substrate. 

Tables 5.17 and 5.18 contain a selected group of compounds for which the dipole moment is given. An extensive collection of dipole moments (approximately 7000 entries) is contained in A. L. McClellan, Tables of Experimental Dipole Moments, W. H. Freeman, San Francisco, 1963. A critical survey of 500 compounds in the gas phase is given by Nelson, Tide, and Maryott, NSRDS-NBS 10, Washington, D.C., 1967.

In addition, researchers can survey the surface and clefts of a macromolecule for potential receptor sites based on Hgand distance ranges "use the common distance range of the superimposed atoms" (116) to faciHtate the development of a "pharmacophore" or critical contact assembly besides the Hgand... 

A. Noshay and J. E. McGrath, Block Copolymers Overview and Critical Survey, Academic Press, Inc., New York, 1977. 

With disk diameters above 5.25 in., all parameters, eg, water absorption and thermal expansion, become more critical which aggravates the expansion or warp of disks. If in the future disk rotation speeds have to be increased significantly to boost data transfer rates, higher demands will be placed on warp (tilt angle) and modulus to avoid creeping (ie, irreversible elongation in radial direction). A survey of the requirement profile for the substrate material of optical disks is given in Table 5 (182,186,187,189). 

In this section a survey is given of the critical protection potentials as well as the critical potential ranges for a possible application of electrochemical protection. The compilation is divided into four groups for both cathodic and anodic protection with and without a limitation of the protection range to more negative or more positive potentials respectively. 

Volume 2 The Control of the Reactivity of Solids. A Critical Survey of the Factors that... 

Non-complex and/or non-critical applications in mechanical design can also make use of probabilistic design techniques and justify a more in-depth approach if the benefits are related to practitioners and customers alike. Surveys have indicated that many products in the industrial sector have in the past been overdesigned (Kalpakjian, 1995). That is, they were either too bulky, were made of materials too high in quality, or were made with unwarranted precision for the intended use. Overdesign may result from uncertainties in design calculations or the concern of the designer and manufacturer over product safety in order to avoid user injury or... 

Detailed, critical surveys of the variants and complexities of crystal growth from the melt were published for low-melting metals by Goss (1963) and for high-melting metals (which present much greater difficulties) by Schadler (1963). 

Something rather different was the set of 7 volumes of the International Critical Tables masterminded by the International Union of Pure and Applied Physics, edited by Edward Washburn, and given the blessing of the International Research Council (the predecessor of the International Council of Scientific Unions, ICSU). This appeared in stages, 1926-1933, once only when Washburn died in 1934, the work died with him . This last quotation comes from a lively survey of the history of ICSU (Greenaway 1996) this book has an entire chapter devoted to Data, and Scientific Information . 

Information about this splendid compilation came to me from a chemist, Robert Weast (1985), who was editor from 1952 until 1988... 37 years He also informed me that the creation (jointly by the American Chemical Society and the American Institute of Physics) of the Journal of Physical and Chemical Reference Data, which began publication in 1972, was encouraged by the results of a survey which indicated how widely the Rubber Bible was used. Weast describes this journal as a truly outstanding source of critically evaluated data . In saying this, he underlined the crucial role of editors and contributors critical judgment in selecting data for such compilations. David Tide, the editor of the journal, in 1989 succeeded Robert... 

Numerous methods for the alkaloidal assay of lobelia and its galenical preparations have been published and two recent critical surveys, by a special committee of the Society of Public Analysts and by Caulkin, indicate that the process of Markwell is satisfactory. Processes for the isolation and separation of the various alkaloids have been protected by patent. Balandin states that Lobelia sessiliflora contains less alkaloid than L. injiata but yields a high-quality lobeline. 

Tobacco and its alkaloids have long ceased to have any therapeutic importance, but their extensive use as insecticides and the demand for nicotine for the manufacture of nicotinic acid have stimulated interest in processes of extraction and methods of estimation. On the latter subject there is a voluminous literature, of which critical resumes have been published by various authors.Recent work on this subject has been specially concerned with (1) the development of miero- and semi-miero-methods suitable for estimating nieotine in tobacco smoke and the distribution of nieotine on sprayed garden produce, in treated soils and in tobaeeo leaves,(2) the study of conditions necessary to ensure satisfactory results in using particular processes, " and (3) methods of separation and estimation of nicotine, nomicotine and anabasine in mixtures of these bases. ) In the United States and in Russia considerable interest is being shown in the cultivation of types of tobacco rich in nicotine, in finding new industrial uses for tobacco and its alkaloids, and in possible by-products from tobacco plants such as citric and malic acids, i " Surveys of information on tobacco alkaloids have been published by Jackson, i Marion and Spath and Kuffner. ... 

A number of groups have criticized the ideas of Dauben and Noyce, especially the concept of PDC. Kamernitzsky and Akhrem, " in a thorough survey of the stereochemistry of addition reactions to carbonyl groups, accepted the existence of SAC but not of PDC. They point out that the reactions involve low energies of activation (10-13 kcal/mole) and suggest that differences in stereochemistry involve differences in entropies of activation. The effect favoring the equatorial alcohols is attributed to an electrostatic or polar factor (see also ref. 189) which may be determined by a difference in the electrostatic fields on the upper and lower sides of the carbonyl double bond, connected, for example, with the uncompensated dipole moments of the C—H bonds. The way this polar effect is supposed to influence the attack of the hydride is not made clear. 

If a survey is administered throughout a facility, it is critical that it be understood and believed to be confidential staff should be encouraged to forward their responses directly to the PSM team and signatures should be optional. 

Data on operating conditions can also be obtained from shift logsheets, where critical conditions are often recorded, or by conducting a survey of conditions in the control room and in the field. 

These remarkable observations stimulated an investigation to understand the origin of the directing effect. To clarify the contribution of the axially- and equato-rially-oriented oxygen atoms in the ketal, a survey of the reaction of three confor-mationally biased t-butyl cyclohexenone ketals 78, 81 and 84 was undertaken (Scheme 3.26) [56]. In each case, careful conformational analysis provides critical clues to rationalizing selectivity. 

The first step is to determine the types of plant equipment and systems that are to be included in your program. A plant survey of your process equipment should be developed that lists every critical component within the plant and its impact on both production capacity and maintenance costs. A plant process layout is invaluable during this phase of program development. It is very easy to omit critical machines or components during the audit. Therefore, care should be taken to ensure that all components that can limit production capacity are included in your list. 

Ulanovskii, I. B., Conditions for Cathodic Protection of Stainless Steels in Crevices , Zashchita Metal, 1, 643 (1965) C.A., 64, 10751 Holmes, D. R. and Mann, G. M. W., A Critical Survey of Possible Factors Contributing to Internal Boiler Corrosion , Corrosion, 21, 370 (1965)... 

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