Big Chemical Encyclopedia

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

Articles Figures Tables About

Tables purpose

Standard general purpose software as given in table 5 is used... [Pg.456]

The data given in Table II-4 were selected with the purpose of providing a working stock of data for use in problems as well as a convenient reference to... [Pg.37]

Neural networks have been applied to IR spectrum interpreting systems in many variations and applications. Anand [108] introduced a neural network approach to analyze the presence of amino acids in protein molecules with a reliability of nearly 90%. Robb and Munk [109] used a linear neural network model for interpreting IR spectra for routine analysis purposes, with a similar performance. Ehrentreich et al. [110] used a counterpropagation network based on a strategy of Novic and Zupan [111] to model the correlation of structures and IR spectra. Penchev and co-workers [112] compared three types of spectral features derived from IR peak tables for their ability to be used in automatic classification of IR spectra. [Pg.536]

The set of parameters given in Table 11.1 is by no means unique, since any independent set of combinations of the given parameters will serve equally well. The particular set adopted will depend primarily on the purpose for which they are to be used. Thus, if we are interested in the dependence of the effectiveness factor on one particular physical variable, it is obviously convenient to choose the dimensionless parameters in such a way that all but one are independent of this variable. A plot of the effectiveness factor against one dimensionless parameter will then summarize the desired information. [Pg.126]

The parameters given In Table 11.1 are not well suited for this purpose, since both 3 and depend on. However, if we replace by Che parameter... [Pg.126]

The properties of a number of sugars are coUected in Table 111,139 the specific rotations in water are included for reference purposes. [Pg.456]

The melting points of the derivatives of a number of selected sulphonic acids are collected in Table IV,33 the melting points of the corresponding sulphonyl chlorides are included for purposes of reference. [Pg.555]

Davies and Warren have investigated the nitration of naphthalene, ace-naphthene and eight dimethylnaphthalenes in acetic anhydride at o °C. Rates relative to naphthalene were determined by the competition method, and the nitro-isomers formed were separated by chromatographic and identified by spectrophotometric means. The results, which are summarised in the table, were discussed in terms of various steric effects, and the applicability of the additivity rule was examined. For the latter purpose use was made of the data of Alcorn and Wells (table 10.2) relating to the nitration of monomethyl-naphthalenes at 25 °C. The additivity rule was found to have only limited utility, and it was suggested that the discrepancies might be due in part to the... [Pg.228]

The heats of formation of most organic com pounds are derived from heats of reaction by arith metic manipulations similar to that shown Chemists find a table of AH values to be convenient because it replaces many separate tables of AH° values for indi vidual reaction types and permits AH° to be calcu lated for any reaction real or imaginary for which the heats of formation of reactants and products are available It is more appropriate for our purposes however to connect thermochemical data to chemi cal processes as directly as possible and therefore we will cite heats of particular reactions such as heats of combustion and heats of hydrogenation rather than heats of formation... [Pg.86]

In Table 1.8 are listed characteristic groups that are cited only as prefixes (never as suffixes) in substitutive nomenclature. The order of listing has no significance for nomenclature purposes. [Pg.17]

The abbreviated table on the next page, which gives critical values of z for both one-tailed and two-tailed tests at various levels of significance, will be found useful for purposes of reference. Critical values of z for other levels of significance are found by the use of Table 2.26b. For a small number of samples we replace z, obtained from above or from Table 2.26b, by t from Table 2.27, and we replace cr by ... [Pg.200]

Table 8.19 pH Values of Biological and Other Buffers for Control Purposes 8.110... [Pg.828]

A saturated aqueous solution in contact with an excess of a definite solid phase at a given temperature will maintain constant humidity in an enclosed space. Table 11.4 gives a number of salts suitable for this purpose. The aqueous tension (vapor pressure, in millimeters of Hg) of a solution at a given temperature is found by multiplying the decimal fraction of the humidity by the aqueous tension at 100 percent humidity for the specific temperature. For example, the aqueous tension of a saturated solution of NaCl at 20°C is 0.757 X 17.54 = 13.28 mmHg and at 80°C it is 0.764 X 355.1 = 271.3 mmHg. [Pg.1083]

This book is the result of a number of years experience in the compiling and editing of data useful to chemists. In it an effort has been made to select material to meet the needs of chemists who cannot command the unlimited time available to the research specialist, or who lack the facilities of a large technical library which so often is not conveniently located at many manufacturing centers. If the information contained herein serves this purpose, the compiler will feel that he has accomplished a worthy task. Even the worker with the facilities of a comprehensive library may find this volume of value as a time-saver because of the many tables of numerical data which have been especially computed for this purpose. [Pg.1289]

The pore systems of solids are of many different kinds. The individual pores may vary greatly both in size and in shape within a given solid, and between one solid and another. A feature of especial interest for many purposes is the width w of the pores, e.g. the diameter of a cylindrical pore, or the distance between the sides of a slit-shaped pore. A convenient classification of pores according to their average width originally proposed by Dubinin and now officially adopted by the International Union of Pure and Applied Chemistry is summarized in Table 1.4. [Pg.25]

Sample Distributions and the Central Limit Theorem Let s return to the problem of determining a penny s mass to explore the relationship between a population s distribution and the distribution of samples drawn from that population. The data shown in Tables 4.1 and 4.10 are insufficient for our purpose because they are not large enough to give a useful picture of their respective probability distributions. A better picture of the probability distribution requires a larger sample, such as that shown in Table 4.12, for which X is 3.095 and is 0.0012. [Pg.77]

Precision The precision of a potentiometric measurement is limited by variations in temperature and the sensitivity of the potentiometer. Under most conditions, and with simple, general-purpose potentiometers, the potential can be measured with a repeatability of +0.1 mV. From Table 11.7 this result corresponds to an uncertainty of +0.4% for monovalent analytes, and +0.8% for divalent analytes. The reproducibility of potentiometric measurements is about a factor of 10 poorer. [Pg.495]

The elements listed in the table of Figure 15.2 are of importance as environmental contaminants, and their analysis in soils, water, seawater, foodstuffs and for forensic purposes is performed routinely. For these reasons, methods have been sought to analyze samples of these elements quickly and easily without significant prepreparation. One way to unlock these elements from their compounds or salts, in which form they are usually found, is to reduce them to their volatile hydrides through the use of acid and sodium tetrahydroborate (sodium borohydride), as shown in Equation 15.1 for sodium arsenite. [Pg.99]

The previous discussion has concentrated on major factors likely to be important in choosing the best mass spectrometer for a given defined purpose. Clearly, there are likely to be other issues that need to be considered, and instrument price will be one of these. The major considerations are listed in Tables 39.1-4. [Pg.285]

The Maxwell and Voigt models of the last two sections have been investigated in all sorts of combinations. For our purposes, it is sufficient that they provide us with a way of thinking about relaxation and creep experiments. Probably one of the reasons that the various combinations of springs and dash-pots have been so popular as a way of representing viscoelastic phenomena is the fact that simple and direct comparison is possible between mechanical and electrical networks, as shown in Table 3.3. In this parallel, the compliance of a spring is equivalent to the capacitance of a condenser and the viscosity of a dashpot is equivalent to the resistance of a resistor. The analogy is complete... [Pg.172]

The purpose of this problem is to consider numerically the effect of including more than two Maxwell elements in the model for a relaxation experiment. Prepare a table analogous to Table 3.2 for a set of four Maxwell elements having the following properties ... [Pg.194]

The purpose of such scmbbing operations may be any of the following gas purification (eg, removal of air pollutants from exhaust gases or contaminants from gases that will be further processed), product recovery, or production of solutions of gases for various purposes. Several examples of appHed absorption processes are shown in Table 1. [Pg.18]

Typical values of important properties of general purpose acetal resins (homopolymer and copolymer) are collected in Table 2. Properties in the table were deterrnined on specimens subjected only to the conditioning required by the ASTM procedure. In this case, values measured for homopolymer are characteristically higher than those for copolymer. [Pg.56]

Table 4. Nonfilled Acetal Resins, General Purpose... Table 4. Nonfilled Acetal Resins, General Purpose...
Development of toughened acetals has recendy dourished. One such grade, Delrin lOOST, boasts a notched-impact strength of 900 J/m (16.86 ft-lb/in.) at 23°C, substantially higher than that of nonmodified, general purpose grades (Table 2). [Pg.59]

Table 1. Material Properties of General Purpose and Heat Distortion Resistant ABS ... Table 1. Material Properties of General Purpose and Heat Distortion Resistant ABS ...
Olefin fibers are used for a variety of purposes from home furnishings to industrial appHcations. These include carpets, upholstery, drapery, rope, geotextiles (qv), and both disposable and nondisposable nonwovens. Fiber mechanical properties, relative chemical inertness, low moisture absorption, and low density contribute to desirable product properties. Table 7 gives a breakdown of olefin fiber consumption by use (73—75). Olefin fiber use in apparel... [Pg.321]

Tables 2—5 Hst some typical properties or ranges of properties for the more common film and sheet products. Although these values are good for comparative purposes, actual performance tests are best to determine suitabiHty for use. Properties of multiple-layer films or sheets in laminar stmctures cannot always be predicted from values for the individual polymer layers. Use conditions of stress, temperature, humidity, and light exposure all strongly influence performance. Film and sheet manufacturers can recommend product combinations or variations that may provide significant performance advantages to the user. Tables 2—5 Hst some typical properties or ranges of properties for the more common film and sheet products. Although these values are good for comparative purposes, actual performance tests are best to determine suitabiHty for use. Properties of multiple-layer films or sheets in laminar stmctures cannot always be predicted from values for the individual polymer layers. Use conditions of stress, temperature, humidity, and light exposure all strongly influence performance. Film and sheet manufacturers can recommend product combinations or variations that may provide significant performance advantages to the user.

See other pages where Tables purpose is mentioned: [Pg.179]    [Pg.742]    [Pg.179]    [Pg.742]    [Pg.942]    [Pg.175]    [Pg.144]    [Pg.139]    [Pg.236]    [Pg.159]    [Pg.82]    [Pg.8]    [Pg.75]    [Pg.135]    [Pg.276]    [Pg.432]    [Pg.202]    [Pg.217]    [Pg.13]    [Pg.195]    [Pg.340]    [Pg.60]   
See also in sourсe #XX -- [ Pg.533 ]




SEARCH



© 2024 chempedia.info