Big Chemical Encyclopedia

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

Articles Figures Tables About

Limit mathematical

The actual value of (7 f) for finite k must lie somewhere between the two limits. Mathematically, this constraint can be expressed as... [Pg.228]

I have tried to present material as clearly and logically as possible, giving sufficient detail in the derivations to make them easy to follow. The text takes into account the limited mathematics and physics background of the average chemistry student. However, in no sense is the treatment superficial or watered down. ... [Pg.252]

Since, as discussed above, it is impossible to achieve dynamic similarity between laboratory and full scale, the predictive capability of empirical modeling of crystallization is limited. Mathematical modeling also has its shortcomings. Suspension flows in crystallizers are turbulent, two and perhaps even three phase (for boiling crystallizers), the particle size is distributed, and the geometry is complicated with perhaps multiple moving parts (impellers). This is of course beyond the possibility of analytical solution of the equations of motion, so we must turn to computational fluid dynamics (CFD). However, even CFD is not capable of successfully dealing with all of these features. Successful computational models of crystallizers to date are limited to very specific limited problems. [Pg.191]

However, the two-sink model as well as other existing adsorption (sink) models do not seem to be able to describe the strong asymmetry between the adsorption/desorption of VOCs on/from indoor surface materials (the desorption process is much slower than the adsorption process). Diffusion combined with internal adsorption is assumed to be capable of explaining the observed asymmetry. Diffusion mechanisms have been considered to play a role in interactions of VOCs with indoor sinks. Dunn and Chen (1993) proposed and tested three unified, diffusion-limited mathematical models to account for such interactions. The phrase unified relates to the ability of the model to predict both the ad/absorption and desorption phases. This is a very important aspect of modeling test chamber kinetics because in actual applications of chamber studies to indoor air quality (lAQ), we will never be able to predict when we will be in an accumulation or decay phase, so that the same model must apply to both. Development of such models is underway by different research groups. An excellent reference, in which the theoretical bases of most of the recently developed sorption models are reviewed, is the paper by Axley and Lorenzetti (1993). The authors proposed four generic families of models formulated as mass transport modules that can be combined with existing lAQ models. These models include processes such as equilibrium adsorption, boundary layer diffusion, porous adsorbent diffusion transport, and conveetion-diffusion transport. In their paper, the authors present applications of these models and propose criteria for selection of models that are based on the boundary layer/conduction heat transfer problem. [Pg.165]

At high quencher concentrations, the decay of the excited state in the aqueous phase will be very fast and the exit from the supramolecular system will be rate limiting. Mathematically, at high quencher concentrations, the last term in Eq. (25) is negligible, and the observed rate constant is either a constant value corresponding to the sum of and kp when fc,(eff) is zero, or a linear dependence with increasing quencher concentration is observed ... [Pg.437]

Burges, C.J.C. (1998). A tutorial on support vector machines for pattern recognition. Data Mining and Knowledge Discovery. Vol. 2, pp. 121-167. ISSN 1384-5810 Chrmg, C.F. (1993). Estimation of covariance matrix from geochemical data with observations below detection limits. Mathematical Geology. Vol. 25, pp. 851-865. ISSN 1573-8868... [Pg.36]

Here we introduce models commonly used to represent the composition dependence of excess properties in liquid mixtures. Just as in 4.5 for volumetric equations of state, the models considered here are semitheoretical they may have some limited mathematical or physical basis, but they inevitably contain parameters whose values must be obtained from experimental data. The emphasis here is on the composition dependence of y, because, for condensed phases, composition is the most important variable temperature is next in importance, and pressure is least important. [Pg.211]

The axial symmetry of a magnetic field, effective as it is in splitting the degeneracy of p (and also d, /, etc.) atomic orbitals, has several disadvantages from the point of view of chemical bonding. The limited mathematical sophistication of many experimentalists leaves them uncomfortable in the face of the... [Pg.33]

There are also some important limitations. Mathematical programming models have a lower level of validity compared to some other typies of models—particularly, simulation. In the supply chain configuration context, mathematical programming models have difficulties representing the dynamic and stochastic aspects of the problem. Additionally, solving of many supply chain configuration problems is computationally challenging. [Pg.152]

This book is intended for first-year graduate and advanced undergraduate courses in qnantnm chemistry. This text provides students with an in-depth treatment of quantnm chemistry, and enables them to nnderstand the basic principles. The limited mathematics backgronnd of many chemistry stndents is taken into account, and reviews of necessary mathematics (snch as complex nnmbers, differential equations, operators, and vectors) are inclnded. Derivations are presented in fnll, step-by-step detail so that students at all levels can easily follow and nnderstand. A rich variety of homework problems (both qnantitative and conceptnal) is given for each chapter. [Pg.712]

The two books on lattice theory that we are recommending have been characterized as Elementary texts recommended for those with limited mathematical maturity It seems therefore appropriate to clarify somewhat ambignons notion of mathematical maturity. What is mathematical matnrity In searching for an answer, we came across a collection of qualities, presented in the list below (most of which we have extracted from [16,17]). On one side, the list below characterizes mathematicians, and on the other side, it allows the rest of us to get an impression of how many mathematical qnalities we may possess We expect many readers may be snrprised to find that they may have several hidden mathematical abilities themselves, which they have not recognized as snch. [Pg.25]

Jean-Marie-Constant Duhamel (1797-1872) rounded off the basic theory by defining its limitations. Mathematical models of real situations could be constructed, but not necessarily solved. Duhamel identified tests for these insoluble forms, which would have to be tackled by other means, the iterative procedures and successive approximations that are suited to mechanical calculators. [Pg.108]


See other pages where Limit mathematical is mentioned: [Pg.104]    [Pg.1074]    [Pg.539]    [Pg.373]    [Pg.98]    [Pg.145]    [Pg.115]    [Pg.233]    [Pg.195]    [Pg.456]    [Pg.461]    [Pg.546]   
See also in sourсe #XX -- [ Pg.113 ]

See also in sourсe #XX -- [ Pg.113 ]




SEARCH



© 2024 chempedia.info