Computer-assisted calculations

An alternative metlrod of solution to these analytical procedures, which is particularly useful in computer-assisted calculations, is the finite-difference technique. The Fourier equation describes the accumulation of heat in a thin slice of the heated solid, between the values x and x + dx, resulting from the flow of heat tlirough the solid. The accumulation of heat in the layer is the difference between the flux of energy into the layer at x = x, J and the flux out of the layer at x = x + dx, Jx +Ox- Therefore the accumulation of heat in the layer may be written as... 

Molecular modeling itself can be simply described as the computer-assisted calculation, modulation, and visualization of realistic 3D-molecular structures and their physical-chemical properties using force fields/ molecular mechanics. 

Finkelstein, N. P., 1999. Addendum to The activation of sulphide minerals for flotation a review. Inter. J. Miner. Process, 55(4) 283 - 286 Fomasiero, D., Montalti, M., Ralston, J., 1995. Kinetics of adsorption of ethyl xanthate on pyrrhotite in situ UV and infiared spectroscopic studies. Langmuir, 11 467 - 478 Forssberg, K. S. E., Antti, B. M., Palsson, B., 1984. Computer-assisted calculations of thermodynamic equilibria in the chalcopyrite-ethyl xanthate system. In M. J. Jones and R. Oblatt (eds.). Reagents in the Minerals Industry. IMM, Rome, Italy, 251 - 264 Fuerstenau, M. C., Kuhn, M. C., Elgillani, D. A., 1968. The role of dixanthogen in xaomthate flotation ofpyrite. Trans. AIME, 241 437 Fuerstenau, M. C. and Sabacky, B. J., 1981. Inter. J. Miner. Process, 8 79 - 84 Fuerstenau, M. C., Misra, M., Palmer, B. R., Xanthate adsorption on selected sulphides in the presence of oxygen. Inter. J. Miner. Process... 

The mechanism of (3-lactam formation has been investigated extensively. But the rationale for the observed diastereoselectivity in certain cases remains unknown. It has been demonstrated that the stereoselectivity depends on the structure of the imine, acid-chloride, order of addition of the reagents, solvent, temperature, bases, and many other conditions. In many cases, cis (3-lactam was found to be the exclusive or major product when acid chloride (equivalent) was added drop-wise at low-to-room temperature to the solution of imines and a base. However, a trans (3-lactam was the major or exclusive product obtained when a tertiary base was slowly added to the imine and acid chloride (equivalent) solution at high temperature. Georg and Ravikumar established a few rules regarding stereoselectivity in the formation of (3-lactam rings [122]. Computer-assisted calculations were advanced to explain the stereochemical preferences [140-144]. Cossio et al. [140-143] and... 

The exact percentage of ketone formation via the alcohol intermediate cannot be defined at this point. Moreover, no evidence exists for the formation of similar intermediates from the analogous primary mercurials. Further rate studies, including computer-assisted calculations for coupled consecutive and competing reaction systems, are clearly needed to solve this complex problem. 

An algorithm [3] suitable for manual or computer-assisted calculations proceeds as follows ... 

This study emphasises the special behaviour of ceria-zirconia catalysts and related compounds exhibiting very high oxygen diffusivity. The use of refined mathematical models and computer-assisted calculations are required for processing the data of isotopic exchange with the highest efficiency and accuracy. 

With the development of tools and techniques for computer-assisted calculations and simulations, knowledge of thermophysical properties at elevated temperatures up into the liquid phase has become even more important for the metal-working industry and related fields. Advances in computer-based simulations allow simulations of heat transport, solidification shrinkage, residual stress, or even predictions of microstructures, to name a few. 

A more simple, but purely empirical, approach to the estimation of 7 was suggested by Meissner and Tester (1972) who claimed applicability up to saturation or 20 molar. They noted that for over a 100 electrolytes a plot of a reduced activity coefficient versus the ionic strength, I, formed a family of non-intersecting curves. They proposed methods of interpolation and extrapolation working from the basis of at least one known value of 7 for a concentrated solution of the chosen electrolyte. A survey of the use of this method, and its subsequent development for computer-assisted calculations (Meissner and... 

If the amino acid sequence of an enzyme is known either entirely or even in part, computer-assisted calculations can provide estimated three-dimensional structures of enzymes [336]. This is done by comparing the known parts of the enzyme in question with other enzymes whose amino acid sequence and three-dimensional structures are already known. Depending on the percentage of the homology, i.e., overlap , of the amino acid sequences, the results are more or less certain. In general, an overlap of about 60% is sufficient for good results less is considered too inaccurate. 

In addition some computer assisted calculations will help to simulate the dosages of the product and see if they are compatible with lab study (MIC, killing tests). Other simulation can be carried out using lithium chloride and measuring by atomic absorption its dilution with time in the circuits after a shock dosage. 

The batch house is solely responsible for the raw materials and cullets. Through cooperation with the Purchasing, the Research and Development, and the Melting Departments, a reliable, inexpensive supply of materials for the melting process is ensured. The computer-assisted calculation of the glass batch, taking the current raw materials analyses into consideration, and automatic batch weighing-in are indispensable aids. 

Figure 2 Effect of hypoxia on cellular p53. Relative cellular fluorescence intensity of p53 immunofluorescence-stained neurons was determined by computer-assisted calculation of the ratio of the mean pixel intensity of experimental over control (21% O2). Note that altering either the severity or duration increased the percentage of neurons showing p53.

Computer assisted calculations were carried out on the basis of the kinetic scheme shown. 

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