Big Chemical Encyclopedia

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

Articles Figures Tables About

Small component definition

Hence, = I + 1 if k > 0 and = I — 1 if k < 0. Consequently, in the Dirac-Pauli representation and have definite parity, (—1) and (—1) respectively. It is customary in atomic physics to assign the orbital angular momentum label I to the state fnkm.j- Then, we have states lsi/2, 2si/2) 2ri/2, 2p3/2, , if the large component orbital angular momentum quantum numbers are, respectively, 0,0,1, ,... while the corresponding small components are eigenfunctions of to the eigenvalues 1,1,0,2,. [Pg.220]

For low energy surfaces, the dispersion force component is larger than the nondispersion force component which, however, cannot be neglected or assumed to be nonexistent. An exception is paraffin wax. The results of Table III for paraflBn confirm that ya is zero, consistent with a surface composed completely of hydrocarbon entities with no polar components. By this treatment, Tefion turns out to have a small but definite polar component of y (10). [Pg.147]

While organic matter is a small component of sea water, it is important to the biological, chemical and physical processes occurring in the ocean. The analysis of this organic matter in sea water is complicated by the matrix in which it is found and by the arbitrary operational or working definitions (DOC, POC and VOC) used to describe it. The oxidation methods used for analysis of organic carbon in sea water are similar and with skilled opera-... [Pg.436]

This is a valid definition, as it only requires that the small component be integrable, which is certainly the case sinee must be square integrable in order to normalize the Dirac wave function. The pseudo-large component now has the same symmetry properties as the large component. The nonrelativistic limit of the pseudo-large component is the large component, since... [Pg.279]

Here we are explicitly taking into account the fact that the metric has a relativistic correction, a feature that in the Pauli approximation was avoided with the consequence of the appearance of pathological operators. The metric in fact is a combination of projectors onto the large and small components. Using the definitions from (15.40),... [Pg.337]

An alternative to the operator approach is to start from the matrix equations (Filatov 2002). Then the elimination the small-component, the construction of the transformation and the transformed Fock matrix are all straightforward. There is no difficulty with interpretation because the inverse of a matrix is well defined. The matrix to be inverted is positive definite so it presents no numerical problems. The drawback of a matrix method is that the basis set for the small component must be used, at least to construct the potentials that appear in the inverse. In that case, the same number of integrals is required as in the full Dirac-Hartree-Fock method, and there is no reduction in the integral work or the construction of the Fock matrix. [Pg.377]

In contrast to the traditional scientific mechanistic approach, systems engineers prefer the "top>-down" approach that broadens the definition of the system and is more likely to include causes of corrosion failures such as human behavior. This is consistent with the lessons to be learned from the U.K. Hoar Report, which stated that corrosion control of even small components could result in major cost savings because of the effect on systems rather than just the components [2]. [Pg.209]

According to the U.S. Code of Federal Regulations, food additives may be defined as "substances. .. the intended use of which results or may reasonably be expected to result, directly or indirectly, either in their becoming a component of food or otherwise affecting the characteristics of food" (1). Canada and the European Community have adopted similar definitions. According to this broad definition, a food additive is synonymous to a food ingredient. In practice, however, the word additive is limited to substances that are used in small quantities. [Pg.435]

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. [Pg.296]

Time-Dependent Cascade Behavior. The period of time during which a cascade must be operated from start-up until the desired product material can be withdrawn is called the equiUbrium time of the cascade. The equiUbrium time of cascades utilizing processes having small values of a — 1 is a very important quantity. Often a cascade may prove to be quite impractical because of an excessively long equiUbrium time. An estimate of the equihbrium time of a cascade can be obtained from the ratio of the enriched inventory of desired component at steady state, JT, to the average net upward transport of desired component over the entire transient period from start-up to steady state, T . In equation form this definition can be written as... [Pg.83]

Colloidal suspensions are, per definition, mixtures of mesoscopic particles and atomic liquids. What happens if there are several different species of particles mixed in the solvent One can invent several different sorts of mixtures small and large particles, differently charged ones, short and long rods, spheres and rods, and many more. Let us look into the literature. One important question when dealing with systems with several components is whether the species can be mixed or whether there exists a miscibility gap where the components macroscopically phase-separate. [Pg.755]

A typical behavior of amplitude dependence of the components of dynamic modulus is shown in Fig. 14. Obviously, even for very small amplitudes A it is difficult to speak firmly about a limiting (for A -> 0) value of G, the more so that the behavior of the G (A) dependence and, respectively, extrapolation method to A = 0 are unknown. Moreover, in a nonlinear region (i.e. when a dynamic modulus depends on deformation amplitude) the concept itself on a dynamic modulus becomes in general not very clear and definite. [Pg.93]

The importance of dilfusion in a tubular reactor is determined by a dimensionless parameter, SiAt/S = QIaLKuB ), which is the molecular diffusivity of component A scaled by the tube size and flow rate. If SiAtlB is small, then the elfects of dilfusion will be small, although the definition of small will depend on the specific reaction mechanism. Merrill and Hamrin studied the elfects of dilfusion on first-order reactions and concluded that molecular diffusion can be ignored in reactor design calculations if... [Pg.265]

The activities of the various components 1,2,3. .. of an ideal solution are, according to the definition of an ideal solution, equal to their mole fractions Ni, N2,. . . . The activity, for present purposes, may be taken as the ratio of the partial pressure Pi of the constituent in the solution to the vapor pressure P of the pure constituent i in the liquid state at the same temperature. Although few solutions conform even approximately to ideal behavior at all concentrations, it may be shown that the activity of the solvent must converge to its mole fraction Ni as the concentration of the solute(s) is made sufficiently small. According to the most elementary considerations, at sufficiently high dilutions the activity 2 of the solute must become proportional to its mole fraction, provided merely that it does not dissociate in solution. In other words, the escaping tendency of the solute must be proportional to the number of solute particles present in the solution, if the solution is sufficiently dilute. This assertion is equally plausible for monomeric and polymeric solutes, although the... [Pg.269]

Note that the lipophilicity parameter log P is defined as a decimal logarithm. The parabolic equation is only non-linear in the variable log P, but is linear in the coefficients. Hence, it can be solved by multiple linear regression (see Section 10.8). The bilinear equation, however, is non-linear in both the variable P and the coefficients, and can only be solved by means of non-linear regression techniques (see Chapter 11). It is approximately linear with a positive slope (/ ,) for small values of log P, while it is also approximately linear with a negative slope b + b for large values of log P. The term bilinear is used in this context to indicate that the QSAR model can be resolved into two linear relations for small and for large values of P, respectively. This definition differs from the one which has been introduced in the context of principal components analysis in Chapter 17. [Pg.390]


See other pages where Small component definition is mentioned: [Pg.215]    [Pg.215]    [Pg.221]    [Pg.2257]    [Pg.328]    [Pg.213]    [Pg.159]    [Pg.622]    [Pg.632]    [Pg.622]    [Pg.289]    [Pg.316]    [Pg.317]    [Pg.437]    [Pg.523]    [Pg.532]    [Pg.843]    [Pg.54]    [Pg.357]    [Pg.337]    [Pg.1557]    [Pg.2648]    [Pg.27]    [Pg.471]    [Pg.160]    [Pg.122]    [Pg.1287]    [Pg.190]    [Pg.554]    [Pg.214]    [Pg.103]    [Pg.160]    [Pg.27]    [Pg.206]    [Pg.21]   
See also in sourсe #XX -- [ Pg.45 ]




SEARCH



Component definition

© 2024 chempedia.info