Big Chemical Encyclopedia

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

Articles Figures Tables About

Thermodynamic approaches to the

T. Umeda, T. Harada, and K. Shiroko, "A Thermodynamic Approach to the Synthesis of Heat Integration Systems in Chemical Processes," Proceedings of the 12th Symposium on Computer Applications in Chemical Engineering, Montreaux, Swit2edand, 1979, p. 487. [Pg.529]

Enzymatic Catalysis. Enzymes are biological catalysts. They increase the rate of a chemical reaction without undergoing permanent change and without affecting the reaction equiUbrium. The thermodynamic approach to the study of a chemical reaction calculates the equiUbrium concentrations using the thermodynamic properties of the substrates and products. This approach gives no information about the rate at which the equiUbrium is reached. The kinetic approach is concerned with the reaction rates and the factors that determine these, eg, pH, temperature, and presence of a catalyst. Therefore, the kinetic approach is essentially an experimental investigation. [Pg.286]

Umeda, T., Itoh, J., and Shiroko, K. (1979). A thermodynamic approach to the synthesis of heat integration systems in chemical processes. Comp. Chem. Eng. 3, 273-282. [Pg.247]

Equation (13) is valid for r/Nlp < 0.25 (Fig. 3). At much higher extension ratios, the force must increase indefinitely since the molecule is almost straightened out. The thermodynamic approach to the problem of coil stretching for a freely-jointed chain was considered by Treloar [32], who obtained the following expression for the stress-strain relationship when the two chain ends are kept a distance r apart ... [Pg.84]

Before we can apply the extended ab initio atomistic thermodynamics approach to the oxygen-covered surface or the surface/bulk oxide, we have to investigate the structure of the bulk electrode. [Pg.149]

Garcia-Araez N, Climent V, Herrero E, Feliu J, Lipkowski J. 2006. Thermodynamic approach to the double layer capacity of a Pt(lll) electrode in perchloric acid solutions. Electrochim Acta 51 3787. [Pg.500]

Cemy, V., "Thermodynamic Approach to the Travelling Salesman Problem An Efficient Simulation Algorithm", J. Opt. Theory Applic., 45,41-51 (1985). [Pg.393]

Schilling, G., Pantehdes, C.C., 1996. A simple continuous-time process scheduling formulation and a novel solution algorithm. Comput. Chem. Eng., 20(Suppl.) S1221-1226 Umeda, T., Harada, T., Shiroko, K., 1979. A thermodynamic approach to the synthesis of heat integration systems in chemical processes. Comput. Chem. Eng., 3 273-282 Wang, Y.P., Smith, R., 1994. Wastewater minimization. Chem. Eng. Sci., 49(7) 981-1002... [Pg.13]

Privalov, P.L. and N.N. Khechinashvili. 1974. A thermodynamic approach to the problem of stabilization of globular protein structure a calorimetric study. J Mol Biol 86 665-684. [Pg.375]

The statistical thermodynamic approach to the derivation of an adsorption isotherm goes as follows. First, suitable partition functions describing the bulk and surface phases are devised. The bulk phase is usually assumed to be that of an ideal gas. From the surface phase, the equation of state of the two-dimensional matter may be determined if desired, although this quantity ceases to be essential. The relationships just given are used to evaluate the chemical potential of the adsorbate in both the bulk and the surface. Equating the surface and bulk chemical potentials provides the equilibrium isotherm. [Pg.420]

Both of these expressions are catered for in the thermodynamic approach to the concept of ion pairs outlined by Denison and Ramsey (44). Their treatment assumes at the outset that the two oppositely charged ions of an electrolyte (1 1) can only be in physical contact (tight or contact ion pair) or infinitely for apart In other words, the critical approach distance is synonomous with the sum of the ionic radii, and the association energy is numerically far in excess of thermal energy k T. Hence the change in the electrostatic free energy of the system resulting from the dissociation... [Pg.9]

Zotin, A.I. (1974). Thermodynamic Approach to the Problems of Development, Growth and Ageing (In Russian). Nauka, Moscow, 183 pp. [Pg.325]

The reaction of 2-chloroisobutyrophenones and nitromethanide anion has stereose-lectively provided ( )-3-nitro allylic alcohols.58 The Gibbs free enthalpies of reaction in DMSO for carbanion addition, epoxide formation, and rearrangement to 3-nitro allylic alcohol, as elementary steps for the reaction, have been estimated from corresponding neutral gas reactions and using a thermodynamic approach to the transfer of gaseous compounds to DMSO. [Pg.258]

Krishna, R., "A Thermodynamic Approach to the Choice of Alternatives to Distillation," I. Chem. E. Symposium Series, No. [Pg.87]

A comparative study of the kinetic and thermodynamic approaches to the glass transition phenomenon was made by Vijayakumar and Kothandaraman (1987). [Pg.152]

Xanthine Oxidase. This molybdoenzyme is readily available from cows milk in gram quantities (28) and is relatively stable, which accounts for the fact that it is by far the most intensively studied molybdoenzyme. Bray and Swann (5) have reviewed comprehensively the earlier literature, and recent papers by Olson et al. (20) summarize combined kinetic and thermodynamic approaches to the states of the prosthetic groups during catalysis. Two molybdenum, four iron-sulfur centers, and two FAD groups are present in each molecule. An important point raised by Edmondson, et al. (29) is that the rates of internal electron transfer among the prosthetic groups appear to be much more rapid than turnover. Olson et al., (20) deduced that the reduction potentials of the two processes Mo(VI) <— Mo(V) <— Mo(IV) were —60 and —31 mv, respectively, relative to the redox potential for one of the iron-sulfur centers (center II) in the molecule. Thus, at equilibrium one can never have more than a small fraction of molybdenum as... [Pg.393]

Important in combustion is not so much the thermal stability of the material itself but rather the amount and nature of the decomposition products. It is sufficient to compare the LOI of poly(vinyl chloride), whose thermal decomposition begins at 160-175 °C with that of heat resistant phenol-formaldehyde fibers (Kynol). The thermodynamic approach to the problem seems to be most reasonable. It allows to consider the polymer structure to explain the details of the combustion reactions and to estimate the heat of combustion of polymers. [Pg.208]

V. Cemy and S.E. Dreyfus, Thermodynamical Approach to the Traveling salesman problem An efficient simulation algorithm. Journal of Optimization Theory and Applications, 45 (1985) 41. [Pg.178]

In the following application of the above-presented thermodynamic approach to the Na3AlF6-Al203 system, we confront the common approach with the new one with regard to the general dissociation scheme of cryolite, which transforms into the form... [Pg.199]

In the thermodynamic approach to the transition state model the equilibrium constant is related to the standard Gibbs energy change for process (7.4.2). Thus, one writes... [Pg.325]

What Derjaguin considers the central issue of colloidal solutions remains largely unresolved for silica sols. This book mentions the ideas of the proponents of both the kinetic and the thermodynamic approach to the problem of stability of silica sols and is intended to stimulate the continuation of the healthy controversy started at the R. K. Iler Memorial Symposium. In this manner a consensus should eventually be reached that will allow the establishment of common quantitative parameters in the treatment of stability of silica sols and other disperse phase materials composed of polyvalent atoms linked by strong covalent bonds and the explanation of their experimentally observed behavior. [Pg.33]

Let us now consider a combined (Statistical Mechanics and Thermodynamic) approach to the problem of calculating defect numbers. [Pg.70]


See other pages where Thermodynamic approaches to the is mentioned: [Pg.511]    [Pg.234]    [Pg.82]    [Pg.35]    [Pg.772]    [Pg.69]    [Pg.245]    [Pg.1602]    [Pg.198]    [Pg.772]    [Pg.68]    [Pg.174]    [Pg.185]    [Pg.465]   
See also in sourсe #XX -- [ Pg.276 ]




SEARCH



Thermodynamic approach

© 2024 chempedia.info