Component number, computer-simulated

For example, in distillation simulations the distillate and bottoms composition should be called XD(J) and XB(J) in the program. The tray compositions should be called X(NJ), where IV is the tray number starting from the bottom and J is the component number. Many computer scientists put all the compositions into one variable X(NJ) and index it so that the distillate is X(1J), the top tray is X(2J), etc. This gives a more compact program but makes it much more difficult to understand the code. 

Alternatively, results from a computer simulation can be plotted to determine the optimum feed stage. Simulation runs ere performed at several different feed points, keeping the material balance, reflux ratio, and total number of stages constant. Ksy component concentrations in the product streams are plotted against the feed stage number (Fig. 3.7). The minimum is at the optimum feed stage. 

For a number of adsorbate-adsorbent systems it has been found that the intracrystalline self-diffusion of a highly mobile component is drastically reduced by the presence of a second, strongly coadsorbed component. By combining these self-diffusion measurements with a computer simulation of... 

As remarked in the previous subsection, discrete solvent models require the use of statistical procedures to properly describe solvent effects. In exposing the evolution of Warshel s methodologies in Subsection 9.1 several times we indicated the use of computer simulations, and the devices introduced in the model to reduce the number of discrete components, which are objects of the simulation, and hence the computational times. 

A series of computer-simulated chromatograms has been generated to test the validity of a procedure derived from the statistical model for calculating the number of randomly distributed components when many of them are obscured by overlap. Plots of the logarithm of the peak count versus reciprocal peak capacity are used for this purposTI TRese plots are shown to provide reasonable estimates of the total number of components In the synthetic chromatograms. 

These dynamic features in the trans-bUayer direction can be averaged for the collective behavior of many lipid molecules and plotted as the averaged electron density profiles of various Upid groups and segments. In computer simulations, the electron density profile can be calculated on the basis of the atomic number and the so-called partial charges for aU heavy atoms (i.e., G, O, N, and P). The summation of all components gives the total electron density profile, which is typically what is measured experimentally by X-ray diffraction. Figure 3.6 shows an example of an... 

When stimulated by chemoattractants, eukaryotic cells respond through a combination of temporal and spatial dynamics. These responses come about because of the interaction of a large number of signaling components. The complexity of these systems makes it hard to understand without a means of systematically generating and testing hypotheses. Computer simulations have proved to be useful in testing conceptual models. Here we outline the steps required to develop these models. 

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