Big Chemical Encyclopedia

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

Articles Figures Tables About

Calculations, basis for

The choice of the basis for a calculation often determines whether the calculation proves to be simple or complex. As with the choice of system boundaries, no all-embracing rules or procedures can be given for the selection of the right basis for [Pg.56]


It is of interest in the present context (and is useful later) to outline the statistical mechanical basis for calculating the energy and entropy that are associated with rotation [66]. According to the Boltzmann principle, the time average energy of a molecule is given by... [Pg.582]

I h c concept of alorn lypes migfii he considered ihc most funda-nicri tal topic in nioiccular m ech an ics an d Iics beh in d all aspects of the approach,. tom types, not atoms, are the fiindamcn tal basis for calculating interactions in rn olecu lar m ech an ics. [Pg.169]

The lattice model that served as the basis for calculating ASj in the last section continues to characterize the Flory-Huggins theory in the development of an expression for AHj . Specifically, we are concerned with the change in enthalpy which occurs when one species is replaced by another in adjacent lattice sites. The situation can be represented in the notation of a chemical reaction ... [Pg.521]

The basis for calculation of partial properties from solution properties is provided by this equation. Moreover, the preceding equation becomes... [Pg.517]

Since the composition of the unknown appears in each of the correction factors, it is necessary to make an initial estimate of the composition (taken as the measured lvalue normalized by the sum of all lvalues), predict new lvalues from the composition and the ZAF correction factors, and iterate, testing the measured lvalues and the calculated lvalues for convergence. A closely related procedure to the ZAF method is the so-called ())(pz) method, which uses an analytic description of the X-ray depth distribution function determined from experimental measurements to provide a basis for calculating matrix correction factors. [Pg.185]

The question whieh then arises is What do we call a defect in a nanotube To answer this question, we need to define what would be a perfeet nanotube. Nanotubes are mieroerystals whose properties are mainly defined by the hexagonal network that forms the eentral cylindrical part of the tube. After all, with an aspect ratio (length over diameter) of 100 to 1000, the tip structure will be a small perturbation except near the ends. This is clear from Raman studies[4] and is also the basis for calculations on nanotube proper-ties[5-7]. So, a perfect nanotube would be a cylindrical graphene sheet composed only of hexagons having a minimum of defects at the tips to form a closed seamless structure. [Pg.71]

Classification is based on laboratory tests with synthetic dust and does not provide a basis for calculation of the life of air filters or assessment of the filter s performance in actual application. Moreover, the dust-holding capacity and average efficiency for each classification vary with final pressure loss and... [Pg.683]

If an energy value is found in literature, it is important to know which equation was used as a basis for calculation. [Pg.314]

Formula for the chemical potentials have been derived in terms of the formation energy of the four point defects. In the process the conceptual basis for calculating point defect energies in ordered alloys and the dependence of point defect concentrations on them has been clarified. The statistical physics of point defects in ordered alloys has been well described before [13], but the present work represents a generalisation in the sense that it is not dependent on any particular model, such as the Bragg-Williams approach with nearest neighbour bond energies. It is hoped that the results will be of use to theoreticians as well as... [Pg.346]

The solubility product is learned from measurements of the solubility. In turn, it can be used as a basis for calculations of solubility. Suppose we wish to know how much cuprous chloride, CuCl, will dissolve in one liter of water. We begin by writing the balanced equation for the reaction ... [Pg.174]

Throughout the main text of this book standard solutions and quantities have all been expressed in terms of molarities, moles and relative molecular masses. However, there are still many chemists who have traditionally used what are known as normal solutions and equivalents as the basis for calculations, especially in titrimetry. Because of this it has been considered desirable to include this appendix defining the terms used and illustrating how they are employed in the various types of determinations. [Pg.845]

The basis for calculation is 1 hour operation and 2 kg acetic acid produced. [Pg.239]

Basics Creep data can be very useful to the designer. In the interest of sound design-procedure, the necessary long-term creep information should be obtained on the perspective specific plastic, under the conditions of product usage (Chapter 5, MECHANICAL PROPERTY, Long-Term Stress Relaxation/Creep). In addition to the creep data, a stress-strain diagram under similar conditions should be obtained. The combined information will provide the basis for calculating the predictability of the plastic performance. [Pg.65]

Brinell hardness A common test used to determine the hardness of a material by indentation of a specimen. Pressing a hardened steel ball generally 10 mm diameter down on a specimen carries out the test, and the diameter of the subsequent impression formed provides a basis for calculating hardness. [Pg.315]

Suspended solids figures represent theoretical values and are not necessarily measurable in practice. They may be used as one basis for calculating boiler BD requirements, based on the actual FW hardness. [Pg.580]

Equation (1.17) is the basis for calculating 5 from molecular properties using statistical mechanical techniques. The procedure is described in Chapter 10. [Pg.18]

The reason that the Second Law has no quantitative relevance to nonequilibrium states is that it gives the direction of change, not the rate of change. So although it allows the calculation of the thermodynamic force that drives the system toward equilibrium, it does not provide a basis for calculating the all... [Pg.2]

The purpose of this chapter is not to discuss the merits, or lack thereof, of using plasma cholinesterase inhibition as an adverse effect in quantitative risk assessments for chlorpyrifos or other organophosphate pesticides. A number of regulatory agencies consider the inhibition of plasma cholinesterase to be an indicator of exposure, not of toxicity. The U.S. Environmental Protection Agency, at this point, continues to use this effect as the basis for calculating the reference doses for chlorpyrifos, and it is thus used here for assessing risks. [Pg.36]

Mulliken, R. S., Rieke, A., Orloff, D., and Orloff, H. (1949). Overlap integrals and chemical binding. /. Chem. Phys. 17, 510, and Formulas and numerical tables for overlap integrals, /. Chem. Phys. 17, 1248-1267. These two papers present the basis for calculating overlap integrals and show the extensive tables of calculated values. [Pg.93]

The derivation of AEGL values based upon potential carcinogenicity is shown in Appendix C. The assessment, following the methods of the NRC (1985), utilized an inhalation slope factor for 1,1-dimethylhydrazine. This slope factor, however, has been withdrawn from the U.S. EPA IRIS and, therefore, is of uncertain validity. Nonetheless, the assessment shows that acute toxicity is clearly more relevant as a basis for calculation of dimethylhydrazine AEGLs. [Pg.199]

Figure 6.9 (a) Collision diameter dAB (b) simplified basis for calculating frequency of A-B collisions... [Pg.129]

Equation 21.3-16 may be used to convert rate constants from a mass to a particle volume basis for calculation of the Thiele modulus (eg., equation 8.5-20b). In this chapter, (—rA) without further designation means ( -rA)m. [Pg.522]

Basis for calculating capital costs on transit and local inventories are the planned product values. The model supports future inventory value planning based on the raw material price offers. Fig. 82 shows results of the inventory value planning. [Pg.221]


See other pages where Calculations, basis for is mentioned: [Pg.474]    [Pg.36]    [Pg.477]    [Pg.542]    [Pg.848]    [Pg.2107]    [Pg.61]    [Pg.262]    [Pg.408]    [Pg.408]    [Pg.26]    [Pg.19]    [Pg.40]    [Pg.538]    [Pg.61]    [Pg.61]    [Pg.281]    [Pg.105]    [Pg.75]    [Pg.708]    [Pg.120]    [Pg.52]   
See also in sourсe #XX -- [ Pg.40 ]




SEARCH



Basis Sets for Relativistic Calculations

Basis Sets for Relativistic Calculations of Molecules

Basis Sets for the Calculation of Molecular Properties

Basis for

Basis for the flow-sheet calculations

Basis of cost calculation for dredging

Calculations, basis

Choice of basis for calculations

© 2024 chempedia.info