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Chemical Engineering Commons

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Full-Text Articles in Chemical Engineering

Enzyme- Facilitated Transport And Separation Of Organic Acids Through Liquid Membranes, David C. Rethwisch, Anuradha Subramanian, Gao Yi, Jonathan S. Dordick Jan 1990

Enzyme- Facilitated Transport And Separation Of Organic Acids Through Liquid Membranes, David C. Rethwisch, Anuradha Subramanian, Gao Yi, Jonathan S. Dordick

Papers in Biotechnology

The selective separation of organic acids is important for the production of numerous biologially functional rnuleculcs, including amino acids, peptidcs, fats, and pharmaceuticals.' Enzyme, specificalty lipases and proteases, have been used to selectively separate a variety of organic acids; however, multiple steps are usually required,Vn additiun, carbonic anhydrase has been usd in a variety of Eiquid membranes for transport of CO2.) In the present study, we have coupled the selectiviey of enzymes with liquid membranes to provide a single-step method to scicctiveiy separate and purify organic acids.


Increased Separation By Variable-Temperature Stepwise Desorption In Multicomponent Adsorption Processes, Suvit Kulvaranon, Marshall E. Findley, Athanasios I. Liapis Jan 1990

Increased Separation By Variable-Temperature Stepwise Desorption In Multicomponent Adsorption Processes, Suvit Kulvaranon, Marshall E. Findley, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

When more components than desired are adsorbed, adsorption-desorption separation processes may not be satisfactory. However, in the cases of ethanol and water adsorption on activated carbon, propane and propylene adsorption on molecular sieves, and hydrogen sulfide, carbon dioxide, and propane adsorption on molecular sieves, it has been found that a variable-temperature stepwise desorption (VTSD) procedure following the adsorption stage can significantly increase the degree of separation achieved compared to a complete desorption of all adsorbed components. Studies indicate that these increased separations are in part due to nonequilibrium effects. An estimation of economic factors in separating low concentration propylene in …


Effect Of Viscoplastic Flow Rules On The Initiation And Growth Of Shear Bands At High Strain Rates, R. C. Batra, Chang-Soo Kim Jan 1990

Effect Of Viscoplastic Flow Rules On The Initiation And Growth Of Shear Bands At High Strain Rates, R. C. Batra, Chang-Soo Kim

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Marchand and Duffy have reported detailed measurements of the temperature and strain as a shear band develops in a HY-100 steel. Assuming their torsional tests in thin-wall tubes can be adequately modeled by a viscoplastic block undergoing overall adiabatic simple shearing deformations, we investigate the effect of modeling the viscoplastic response of the material by a.power law, and flow rules proposed by Litonski, Bodner and Partom, and Johnson and Cook. Each of these flow rules is first calibrated by using the test data at a nominal strain-rate of 3300 s-1. Then predictions from the use of these flow rules at …