Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Engineering

Effects Of Structural And Kinetic Parameters On The Performance Of Chromatographic Columns Packed With Perfusive And Purely Diffusive Adsorbent Particles, G. A. Heeter, Athanasios I. Liapis Aug 1996

Effects Of Structural And Kinetic Parameters On The Performance Of Chromatographic Columns Packed With Perfusive And Purely Diffusive Adsorbent Particles, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model describing dynamic adsorption in columns with spherical bidisperse perfusive or spherical bidisperse purely diffusive adsorbent particles is used to study the effects of the structural parameters of the adsorbent particles and of the parameters of the adsorption mechanism on the performance of chromatographic systems involving the adsorption of bovine serum albumin onto anion-exchange porous adsorbent particles. Four structural parameters are studied: the particle diameter, d(p), the macropore void fraction, ε(p), the microparticle diameter, d(m) and the parameter φ which affects the value of the permeability of the adsorbent particle. Two parameters of the adsorption mechanism are studied: …


Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian Aug 1996

Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian

Journal of Electrochemistry

Good quality potential-dependent surface Raman spectra of pyridine were obtained for the first time from a series of transition metals,e. g.,Fe,Co,Ni,Ru,Rh,Pd and Pt,which were electrodeposited on non-SERS-active substrates.The influences of the applied potential and the nature of metal on the adsorption behaviors were discussed briefly.This result illustrates that Raman spectroscopy is becoming a more general and powerful tool to study various electrochemical interfaces.


Multi-Component Perfusion Chromatography In Fixed Bed And Periodic Counter Current Column Operation, G. A. Heeter, Athanasios I. Liapis May 1996

Multi-Component Perfusion Chromatography In Fixed Bed And Periodic Counter Current Column Operation, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model of multi-component dynamic adsorption in columns with spherical perfusive and spherical purely diffusive adsorbent particles with a bidisperse porous structure is constructed, solved, and used to study the performance of a binary adsorption system in a single-column fixed-bed process and in a two-column periodic countercurrent process in which the adsorbent is equally distributed over two beds. The total length of the two-column periodic counter-current system is equal to the length of the single-column fixed-bed system. The performance of fixed-bed and periodic counter-current systems with both perfusive and purely diffusive adsorbent particles is examined for different values of …


Determination Of Iron Colloid Size Distribution In The Presence Of Suspended Cells: Application To Iron Deposition Onto A Biofilm Surface, Waihung Lo, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse Apr 1996

Determination Of Iron Colloid Size Distribution In The Presence Of Suspended Cells: Application To Iron Deposition Onto A Biofilm Surface, Waihung Lo, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse

Civil and Environmental Engineering

Transport and deposition of colloidal Fe, Mn and Al oxides play key roles in the cycling of toxic transition metals in aquatic environments because these colloids strongly bind transition metals. Further, attachment of biological cells and biofilm growth on surfaces can indirectly affect toxic metal distribution by influencing the deposition of colloidal oxides to surfaces. To elucidate the mechanisms governing these processes, deposition of colloidal oxides onto surfaces must be evaluated in the presence of suspended and adherent bacterial cells. Both particle size and concentration are expected to influence deposition. An experimental protocol was developed to determine the size distribution …


The Effects Of Multiple Electroplated Zinc Layers On The Inhibition Of Hydrogen Permeation Through An Iron Membrane, D. H. Coleman, G. Zheng, Branko N. Popov, Ralph E. White Jan 1996

The Effects Of Multiple Electroplated Zinc Layers On The Inhibition Of Hydrogen Permeation Through An Iron Membrane, D. H. Coleman, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

The Devanathan-Stachurski permeation technique was used to investigate the rate of hydrogen permeation through an iron membrane with consecutively electroplated zinc layers. Hydrogen evolution rates and hydrogen permeation rates were followed as functions of time at different applied potentials. Hydrogen evolution and permeation decreased with each successive zinc layer until finally reaching an average decrease of 93 and 96%, respectively, as compared with bare iron. Hydrogen surface coverage, exchange current density, absorption-adsorption reaction constant, and hydrogen recombination constant were estimated on bare iron and on zinc-plated iron. It was found that the decrease in the permeation rate of hydrogen through …