Big Chemical Encyclopedia

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

Articles Figures Tables About

May model

This intuition leads us to recognize that the J and rules must be complimentary and that they may model states of water associated with temperature. The choice of these two rules must therefore lead to the attributes of the CA dynamics that have some relationship to the physical properties that change with temperature. These properties then become references for the validity of... [Pg.45]

In this regard, it is noteworthy that while surface bound hydroxycarbenes are postulated species, discrete complexes containing hydroxy- and alkoxy-carbenes have been known since E. O. Fischer s studies beginning in 1964 (56, 57). These complexes are possibly analogous to proposed surface intermediates, and their chemistry may model some of the heterogeneously catalyzed transformations. Coupling of alkoxy carbenes, for example, gives dialkoxy olefins as observed in (20). [Pg.100]

A complementary series of methods for determining the number of significant factors are based on cross-validation. It is assumed that significant components model data , whilst later (and redundant) components model noise . Autopredictive models involve fitting PCs to the entire dataset, and always provide a closer fit to the data the more the components are calculated. Hence the residual error will be smaller if 10 rather than nine PCs are calculated. This does not necessarily indicate that it is correct to retain all 10 PCs the later PCs may model noise which we do not want. [Pg.199]

We may model complex systems by top-down or bottom-up approaches. In the top-down approach, we describe the components from the systemic behavior of the actual system. For example, from the flow balance analysis in a steady-state bacterium, we learn the input and output flows, topology of the network, and the rates of maty metabolic reactions. [Pg.561]

P. M. May, Modelling Metal-Ligand Equihhria in Blood Plasma, in Handbook of Metal-Ligand Interactions in Biological Fluids , ed. G. Berthon, Marcel Dekker Inc., New York, Basel, Hong Kong, 1995, Vol. 2, p. 1184. [Pg.4553]

Snyder and Raghavachari (1984) have suggested that (SiO)2 with the Dy, geometry may model solid amorphous SiO. The existence and structure of solid SiO is a subject of considerable debate. X-ray diffraction (Yasaitis and Kaplow, 1972) yields a Si—O distance of 1.64 A and an O-Si-O angle of 96.7°, in reasonable agreement with those calculated for... [Pg.144]

If we imagine a series of N lenses of focal length = 2q separated by 2/o such that the beam waist occurs midway between any pair of lenses, then we may model the optical system as a transmission line of length 2Nz... [Pg.279]

There are more different ways one can model this situation, depending on the precise type of interaction between the solvated molecule and the solvent. In many cases, these interactions are (partly or purely) of electrostatic nature, meaning that one may model the effects of the solvent as that of creating an external, electrostatic field in which the molecule of interest exists. But, there is also a feed-back between the solute and the solvent. I.e., the solute may in return influence the charge distribution of the solvent, thus ultimately leading to a modified effect of the influence of the solvent. Furthermore, in some cases (that are not at all atypical) hydrogen bonds between the solvent and the solute are important and should, therefore, also be included. [Pg.67]

Dose-response models describe a cause-effect relationship. There are a wide range of mathematical models that have been used for this purpose. The complexity of a dose-response model can range from a simple one-parameter equation to complex multicompartment pharmacokinetic/pharmacodynamic models. Many dose-response models, including most cancer risk assessment models, are population models that predict the frequency of a disease in a population. Such dose-response models typically employ one or more frequency distributions as part of the equation. Dose-response may also operate at an individual level and predict the severity of a health outcome as a function of dose. Particularly complex dose-response models may model both severity of outcome and population variability, and perhaps even recognize the influence of multiple causal factors. [Pg.1174]

Surfactant aggregates (microemulsions, micelles, monolayers, vesicles, and liquid crystals) are recently the subject of extensive basic and applied research, because of their inherently interesting chemistry, as well as their diverse technical applications in such fields as petroleum, agriculture, pharmaceuticals, and detergents. Some of the important systems which these aggregates may model are enzyme catalysis, membrane transport, and drug delivery. More practical uses for them are enhanced tertiary oil recovery, emulsion polymerization, and solubilization and detoxification of pesticides and other toxic organic chemicals. [Pg.265]

The splash zone above the free bubbling zone consists of entrained droplets. We may model this zone as being made up of droplets of uniform size rising in plug flow through the splash zone. The model parameters are... [Pg.319]

The usual treatment of confinement is where the charge p = 37 (r) 2 is essentially zero on the sphere (or hypersphere) r = R and the system may therefore be isolated. For example, if we envisage a large repulsive potential in r > R, then we may model this as an infinite barrier on r = R and consequently F(TJ) = 0. This model isolates the wavefunction completely in r < R and, for the examples considered here, leads to the general form... [Pg.187]

We may model Type 1 integral desaturation by replacing the pure integral term, /, in our simulation by the desaturated integral term. Ip, given at a general time, t, by ... [Pg.286]

The studies of elementary films formed in inverse emulsions and stabilized by different synthetic and natural surfactants revealed that the membrane electric conductivity experiences a sharp increase upon the addition of some biologically active surfactants. For instance, membrane conductivity may increase by five orders of magnitude when trace amounts of valinomycin antibiotic are introduced into the outer aqueous medium of lipid membrane. At the same time the membrane becomes permeable to potassium and hydrogen ions but impermeable to sodium ions. A sharp decrease in electric resistance of synthetic membranes is observed when proteins and enzymes with suitable substrates are introduced into them. By studying the properties of such membranes one may model important biological processes, e.g. the transfer of neural impulses. [Pg.621]

In both cases, as well as in others, one may model the spin behaviour of the system of interest using a Heisenberg Hamiltonian,... [Pg.350]

The binding of norbornene to a triosmium cluster may model the coordination of this molecule to metal surface sites. Reactions of the lightly stabilized cluster Os3(CO)io(NCMe)2 with norbornene (bicyclo[2.2.1]hept-2-ene) led... [Pg.762]

To model the electrodialysis stack, we assume that since there are many cells in a stack the behaviors in different pairs of adjacent dialysate and concentrate channels are the same. If we neglect the potential drop in the electrode cells adjacent to the electrodes as small compared with that in the rest of the system, the potential drop across a channel pair is constant and equal to the total applied voltage divided by the number of channel pairs. The dialysate and concentrate channels are taken to have the same separation 2h (Fig. 6.2.1). Since there is symmetry about the center plane of each channel, we may model the electrodialysis cell pair of Fig. 6.2.1 by one half of the dialysate channel and one half of the adjacent concentrate channel separated by a membrane, as shown in Fig. 6.2.4. For specificity we choose the cation exchange membrane. Both types of membranes are assumed to have the same resistances and thicknesses and to be perfectly selective. To simplify the problem somewhat further, we take the membrane resistance to be small so that the ohmic drop within the membranes may be neglected. [Pg.374]

While results from the task analysis provide task-flow models, they also can provide insights on the manner in which individuals model these process flows (i.e., mental models). Mental models synthesize several steps of a process into an organized imit (Ahen 1997). An individual may model several aspects of a given process, such as the capabflities of a tool or machine, expectations of coworkers, or understandings of support processes (Fischer 1991). These models allow individuals to predict how a process whl respond to a given input, explain a process event, or diagnose the reasons for a malfunction. Mental models are often incomplete and inaccurate, however, so tmder-standings based on these models can be erroneous. [Pg.1210]

In the Nelson and Siegel (1987) method, we may model the implied forward rate yield curve along the entire term stmcture using the following function ... [Pg.109]

By using the aforementioned variables, analysts undertake simulation modelling to generate scenarios of portfolio return. For instance, they may model the number of defaults up to maturity, the recovery rates of these defaults and the timing of defaults. All these variables are viewed as random variables, so they are modelled using a stochastic process. [Pg.483]

When, as in the case of the alanine dipeptide, net charges are present on the atoms, one may model this by means of Coulomb potentials ... [Pg.13]

The second reason lies in the possibility of a multipole containing a sufficiently large number of poles for mimicking a continuous process (the number of poles is not limited). In this way, a multipole may model a transmission line in which dissipation occurs. [Pg.309]


See other pages where May model is mentioned: [Pg.434]    [Pg.101]    [Pg.120]    [Pg.228]    [Pg.2]    [Pg.434]    [Pg.383]    [Pg.112]    [Pg.209]    [Pg.168]    [Pg.2277]    [Pg.358]    [Pg.168]    [Pg.138]    [Pg.667]    [Pg.108]    [Pg.772]    [Pg.387]    [Pg.664]    [Pg.45]    [Pg.1122]    [Pg.239]    [Pg.216]    [Pg.26]    [Pg.344]    [Pg.44]    [Pg.328]   
See also in sourсe #XX -- [ Pg.254 ]




SEARCH



May-van Deemter model

© 2024 chempedia.info