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Articles 1261 - 1290 of 1430

Full-Text Articles in Chemical Engineering

A Red-Dot-Blot Protein Assay Technique In The Low Nanogram Range, Tiilin Marcol, Anuradha Subramanian Jan 1999

A Red-Dot-Blot Protein Assay Technique In The Low Nanogram Range, Tiilin Marcol, Anuradha Subramanian

Papers in Biotechnology

A simple, sensitive, rapid (3 min), and highly reproducible solid-phase assay for the detection of proteins in the low nanogram range (4 ng) is described. The assay is based on differential Pon-ceau S staining of the protein spots on nitrocellulose and quantification of the protein- dye com-plexes on lubricated membranes using a densitometer. The dye solution used for protein stain-ing contained 0.1% Ponceau S in 15% phosphoric acid and 10% ethanol. Proteins were directly spotted onto pre- Ponceau S-stained nitrocellulose membranes, crosslinked with glutaraldehyde, rinsed in NaOH, restained with Ponceau S, and finished by rinsing in acid water at pH …

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A Red-Dot-Blot Protein Assay Technique In The Low Nanogram Range, Tiilin Marcol, Anuradha Subramanian Jan 1999

A Red-Dot-Blot Protein Assay Technique In The Low Nanogram Range, Tiilin Marcol, Anuradha Subramanian

Papers in Biotechnology

A simple, sensitive, rapid (3 min), and highly reproducible solid-phase assay for the detection of proteins in the low nanogram range (4 ng) is described. The assay is based on differential Pon-ceau S staining of the protein spots on nitrocellulose and quantification of the protein- dye com-plexes on lubricated membranes using a densitometer. The dye solution used for protein stain-ing contained 0.1% Ponceau S in 15% phosphoric acid and 10% ethanol. Proteins were directly spotted onto pre- Ponceau S-stained nitrocellulose membranes, crosslinked with glutaraldehyde, rinsed in NaOH, restained with Ponceau S, and finished by rinsing in acid water at pH …

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Liquid Holdup Measurement Techniques In Laboratory High Pressure Trickle Bed Reactors, Muthanna H. Al-Dahhan, Wes Highfill Jan 1999

Liquid Holdup Measurement Techniques In Laboratory High Pressure Trickle Bed Reactors, Muthanna H. Al-Dahhan, Wes Highfill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three Different Techniques, Which Are Tracer, Drainage and Weighing Methods, Are Used to Measure Liquid Holdup in a Laboratory Trickle-Bed Reactor Operated under High Pressure. the Holdup Measurements Are Compared to Determine the Applicability of These Methods at High Pressure Operation. It Was Found that Tracer and Drainage Techniques Give Comparable Values for the Total Liquid Holdup. Although Several Investigators Recommended the Weighing Method over the Others based on their Experiments Performed at Atmospheric Conditions, It Was Found that the Weighing Method Failed to Measure Liquid Holdup Properly at High Pressure Operation.

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Frontal Chromatography Of Proteins: The Effect On Column Performance Of The Restricted Diffusion Of Molecules In Porous Chromatographic Adsorbents, Athanasios I. Liapis, H. Sadikoglu, Orrin K. Crosser Dec 1998

Frontal Chromatography Of Proteins: The Effect On Column Performance Of The Restricted Diffusion Of Molecules In Porous Chromatographic Adsorbents, Athanasios I. Liapis, H. Sadikoglu, Orrin K. Crosser

Chemical and Biochemical Engineering Faculty Research & Creative Works

A theoretical formulation is presented that can be used to describe the dynamic behavior of frontal chromatography of proteins in columns packed with adsorbent particles in which restricted pore diffusion of the adsorbate molecules occurs. The results of this work clearly indicate that the time for breakthrough and the effective utilization of the adsorptive capacity of the chromatographic particles increase as (a) the size of the adsorbate and/or ligand (active site) molecule decreases, (b) the pore connectivity, n(T), of the porous network of the adsorbent particles increases, and (c) the column length, L, increases. Copyright (C) 1998 Elsevier Science B.V.

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Network Modeling Of The Intraparticle Convection And Diffusion Of Molecules In Porous Particles Packed In A Chromatographic Column, J. J. Meyers, Athanasios I. Liapis Dec 1998

Network Modeling Of The Intraparticle Convection And Diffusion Of Molecules In Porous Particles Packed In A Chromatographic Column, J. J. Meyers, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A pore network model (cubic lattice network) is constructed to represent the porous structure in a column packed with porous chromatographic particles. Expressions are developed and used to determine, through the utilization of the pore network model, the intraparticle interstitial fluid velocity and pore diffusivity of a solute as the pore connectivity, n(T), of the porous medium is varied from 2.6 to 6.0. The results show that the intraparticle interstitial velocity and the pore diffusivity increase significantly as the value of the pore connectivity, n(T), increases, and clearly indicate that the pore connectivity, n(T), plays a key role in determining …

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Optimization Of Temperature-Glycerol-Ph Conditions For Fed-Batch Fermentation Process For Recombinant Hookworm (Ancylostoma Caninum) Anticoagulant Peptide (Acap-5) Production By Pichia Pastoris, Mehmet İnan, Vijay Chiruvolu, Kent M. Eskridge, George P. Vlasuk, Kenneth Dickerson, Scott Brown, Michael M. Meagher Dec 1998

Optimization Of Temperature-Glycerol-Ph Conditions For Fed-Batch Fermentation Process For Recombinant Hookworm (Ancylostoma Caninum) Anticoagulant Peptide (Acap-5) Production By Pichia Pastoris, Mehmet İnan, Vijay Chiruvolu, Kent M. Eskridge, George P. Vlasuk, Kenneth Dickerson, Scott Brown, Michael M. Meagher

Papers in Biochemical Engineering

This study was undertaken to determine the optimum pH, temperature and glycerol feed rate for the production of recombinant hookworm (Ancylostoma caninum) anticoagulant peptide (rAcAP-5) by Pichia pastoris using response surface methodology (RSM). A central composite design was used as an experimental design for allocation of treatment combinations in three blocks. The variables selected for study were pH, temperature and glycerol feed rate. pH was the most important variable affecting yield, specific yield and specific activity of rAcAP-5. Glycerol feed rate had a significant effect on the specific activity of rAcAP-5 (% of total secreted protein) while temperature …

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Study On The Estimation And Control Of A Liquid Composite Molding Process, Dennis Sourlas, Susmito Naha, Gary Patterson, Richard Parnas Dec 1998

Study On The Estimation And Control Of A Liquid Composite Molding Process, Dennis Sourlas, Susmito Naha, Gary Patterson, Richard Parnas

Chemical and Biochemical Engineering Faculty Research & Creative Works

An on-line nonlinear receding horizon control algortithm is employed in order to achieve setpoint tracking targets in the context of liquid composite molding processes. The robustness of this control strategy against process-model deviations is tested. Finally, recursive parameter estimation is employed as a means of actively enhancing the performance of the process control algorithm. © 1998 AACC.

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Frontal Chromatography Of Proteins. Effect Of Axial Dispersion On Column Performance, G. A. Heeter, Athanasios I. Liapis Feb 1998

Frontal Chromatography Of Proteins. Effect Of Axial Dispersion On Column Performance, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model describing the dynamic adsorption of proteins in columns packed with spherical porous adsorbent particles is used to study the effect of axial dispersion on the performance of chromatographic systems. The values of the axial dispersion coefficient, D(L), are estimated from a correlation based on a model describing axial dispersion in packed beds that provides satisfactory results when compared with experiment. Simulations of frontal chromatography in systems including axial dispersion and in systems without axial dispersion are made and compared to determine the effect of axial dispersion on the efficiency of the adsorption process; also, the system parameters …

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Modeling Partially Premixed Fast Chemical Reactions In Statistically Homogeneous Turbulent Flow Using One-Dimensional Equations Of Change, Yang Gi Kim, X. B. Reed Jan 1998

Modeling Partially Premixed Fast Chemical Reactions In Statistically Homogeneous Turbulent Flow Using One-Dimensional Equations Of Change, Yang Gi Kim, X. B. Reed

Chemical and Biochemical Engineering Faculty Research & Creative Works

A pseudospectral algorithm has been used to compute solutions u(x,t), Ax,t), B(x,t), and R(x,t) to one-dimensional equations of change incorporating the simple reaction A + B → R for statistically homogeneous random velocity and partially premixed reactant concentration fields. An initial turbulence Reynolds number of 400 has been used, together with Damkohler numbers of 102 and 103 for fast reactions and Schmidt numbers of 10-3, 1, and 102 to span a wide range of diffusivities. Evolving concentration profiles inform intuition in general and provide insight into the evolution of the single-point statistical measures in particular: (A), (B), (a2), (b2), (ab), …

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Experimental Measurements And Simulation Of Mixing And Chemical Reaction In A Stirred Tank, Robertp Zipp, Gary Kent Patterson Jan 1998

Experimental Measurements And Simulation Of Mixing And Chemical Reaction In A Stirred Tank, Robertp Zipp, Gary Kent Patterson

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effects of mixing on the rate of second-order chemical reactions have been studied by measuring the time-average degree of conversion at enough points in a steady-state, continuous-flow stirred reactor to provide comparisons with numerical simulations of the same reactions using a standard Reynolds-averaged turbulence simulation code with an added closure. The reactants were introduced in widely separated feed streams in order to provide a difficult test for the measurements and simulations. Concentration and segregation measurements were made with two fluorescence based methods - one remote and one using a fiber optic probe. The rates of mixing and reaction were simulated …

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Investigation Of A Complex Reaction Network: I. Experiments In A High-Pressure Trickle-Bed Reactor, M. R. Khadilkar, Y. Jiang, M. (Muthanna) H. Al-Dahhan, M. P. Duduković, S. K. Chou, G. Ahmed, R. Kahney Jan 1998

Investigation Of A Complex Reaction Network: I. Experiments In A High-Pressure Trickle-Bed Reactor, M. R. Khadilkar, Y. Jiang, M. (Muthanna) H. Al-Dahhan, M. P. Duduković, S. K. Chou, G. Ahmed, R. Kahney

Chemical and Biochemical Engineering Faculty Research & Creative Works

A High-Pressure Trickle-Bed Reactor Was Used to Achieve High Productivity and Selectivity for the Manufacture of a Key Herbicide Intermediate (Α-Aminomethyl-2-Furanmethanol (Amino Alcohol, AA) from Α-Nitromethyl-2-Furanmethanol (Nitro Alcohol, NA). Raney Nickel Catalysts of Varying Activity Were Prescreened for Suitability in Trickle-Bed Operation. the Effect of Operating Parameters Such as Reactant Feed Concentration, Liquid Mass Velocity, and Temperature on the Yield of Amino Alcohol (AA) for RNi-A Are Discussed. the Superiority of Trickle-Bed Reactors over Others Such as Semibatch and Batch Slurry Systems is Demonstrated. the AA Yield Increases with Decrease in Feed Reactant Concentration and Liquid Mass Velocity, as Well …

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Investigation Of A Complex Reaction Network: Ii. Kinetics, Mechanism And Parameter Estimation, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković, S. K. Chou, G. Ahmed, R. Kahney Jan 1998

Investigation Of A Complex Reaction Network: Ii. Kinetics, Mechanism And Parameter Estimation, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković, S. K. Chou, G. Ahmed, R. Kahney

Chemical and Biochemical Engineering Faculty Research & Creative Works

Conventional Strategies for Discrimination of Intrinsic and Apparent Kinetics from Crushed- and Whole-Catalyst-Pellet Experimental Data, Respectively, Do Not Yield Satisfactory Results for the Reaction Network in the Manufacture of Α-Aminomethyl-2-Furanmethanol (Aminoalcohol) from Α-Nitromethyl-2-Furanmethanol (Nitroalcohol). Laboratory Trickle-Bed Reactor Tests in the Range of Concentration and Product Yield of Commercial Interest Are Utilized to Yield a Reasonable Set of Kinetic Parameters, Which Are Otherwise Unobtainable. This is Accomplished by Proposing a Reaction Network, a Plausible Mechanism, and Optimizing the Kinetic Parameters based on the Reactor-Model-Generated Performance Data to Fit Experimental Output Concentrations of All Species for the Entire Set of Experiments. a …

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Prediction Of Pressure Drop And Liquid Holdup In High-Pressure Trickle-Bed Reactors, M. (Muthanna) H. Al-Dahhan, M. R. Khadilkar, Y. Wu, M. P. Duduković Jan 1998

Prediction Of Pressure Drop And Liquid Holdup In High-Pressure Trickle-Bed Reactors, M. (Muthanna) H. Al-Dahhan, M. R. Khadilkar, Y. Wu, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Holub Et Al. (1992, 1993) Phenomenological Model for Pressure Drop and Liquid Holdup in Trickle Flow Regime at Atmospheric Pressure Was Noted by Al-Dahhan and Duduković (1994) to Systematically Underpredict Pressure Drop at High Pressure and High Gas Flow Rates. in This Study, the Holub Et Al. (1992, 1993) Model Has Been Extended to Account for the Interaction between the Gas and Liquid Phases by Incorporating the Velocity and the Shear Slip Factors between the Phases. as a Result, the Prediction of Pressure Drop at the Operating Conditions of Industrial Interest (High Pressure) Has Been Improved Noticeably Without Any …

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Crossflow Microfiltration Of Recombinant Escherichia Coli Lysates After High Pressure Homogenization, Stuart M. Bailey, Michael M. Meagher Nov 1997

Crossflow Microfiltration Of Recombinant Escherichia Coli Lysates After High Pressure Homogenization, Stuart M. Bailey, Michael M. Meagher

Papers in Biotechnology

Abstract: Crossflow membrane filtration was used to process recombinant Escherichia coli cell lysates containing protein inclusion bodies after high pressure homogenization. The number of passes through the high pressure homogenizer changed the viscosities and average particle sizes of the cell lysates. The different cell lysates were processed with a hollow fiber unit containing microfiltration membranes and a plate and frame unit with either ultrafiltration or microfiltration membranes. There were differences in permeate flux and protein transmission for the various membranes with the best performing membranes giving permeate fluxes greater than 60 L m−2 h−1 and protein transmissions greater than 90%. …

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An Empirical Relation Between The Mark-Houwink-Sakurada Constants, P. Rai, Stephen L. Rosen Sep 1997

An Empirical Relation Between The Mark-Houwink-Sakurada Constants, P. Rai, Stephen L. Rosen

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

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Model Discrimination And Estimation Of The Intraparticle Mass Transfer Parameters For The Adsorption Of Bovine Serum Albumin Onto Porous Adsorbent Particles By The Use Of Experimental Frontal Analysis Data, G. A. Heeter, Athanasios I. Liapis Jul 1997

Model Discrimination And Estimation Of The Intraparticle Mass Transfer Parameters For The Adsorption Of Bovine Serum Albumin Onto Porous Adsorbent Particles By The Use Of Experimental Frontal Analysis Data, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experimental data from a chromatographic system involving the adsorption of bovine serum albumin (BSA) onto porous anion-exchange adsorbent particles packed in a column are presented. The parameters that characterize the mass transfer mechanisms of intraparticle diffusion and convection are estimated by fitting the predictions of dynamic mathematical models describing adsorption in column systems having spherical perfusive and purely diffusive adsorbent Particles to the experimental breakthrough data obtained from the column adsorption system. Both linear and nonlinear expressions for the equilibrium isotherm are considered. The values of the transport parameters are estimated in the time domain for the nonlinear adsorption models …

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Accumulation Of Lead By Anabaena Cylindrica: Mathematical Modeling And An Energy Dispersive X-Ray Study, David T. Swift, Daniel Forciniti Jul 1997

Accumulation Of Lead By Anabaena Cylindrica: Mathematical Modeling And An Energy Dispersive X-Ray Study, David T. Swift, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ability of microorganisms to selectively adsorb various heavy metal ions has been recognized for over a decade. We have investigated the biosorption of lead by an active culture of the cyanobacterium Anabaena cylindrica. Energy dispersive X-ray microanalysis was used to evaluate the different uptake mechanisms in the various subcellular regions. Three were identified; a very fast adsorption mechanism in the cell envelope; a time- dependent deposition reaction on the cell surface; and an adsorption mechanism, also time dependent, on the polyphosphate body inside the cell. Atomic absorption spectrometry was then used to quantify the changes with time of bulk …

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Estimation Of Pore Diameter For Intraparticle Fluid Flow In Hidisperse Porous Chromatographic Particles, G. A. Heeter, Athanasios I. Liapis Feb 1997

Estimation Of Pore Diameter For Intraparticle Fluid Flow In Hidisperse Porous Chromatographic Particles, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A quantitative method is developed and presented for estimating the mean pore diameter, d(pore), that could allow intraparticle fluid flow in the macroporous region of adsorbent particles with a bidisperse porous structure packed in a column. The method is used to estimate the value of d(pore) that is required to obtain specified values of the fraction, F, of the column superficial fluid velocity that is flowing through the macroporous region of the adsorbent particles and the value of d(pore) that is required to obtain specified values of the intraparticle Peclet number, Pe(intra).

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Affinity Adsorption Of Adsorbates Into Spherical Monodisperse And Bidisperse Porous Perfusive And Purely Diffusive Adsorbent Particles Packed In A Column. Parameter Estimation In The Laplace Transform Domain, G. A. Heeter, Athanasios I. Liapis Jan 1997

Affinity Adsorption Of Adsorbates Into Spherical Monodisperse And Bidisperse Porous Perfusive And Purely Diffusive Adsorbent Particles Packed In A Column. Parameter Estimation In The Laplace Transform Domain, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A novel mathematical method for parameter estimation is proposed and used to estimate in the Laplace transform domain the values of the parameters that characterize the mechanisms of intraparticle diffusion and convection in spherical perfusive or purely diffusive adsorbent particles with a monodisperse or with a bidisperse porous structure when the adsorbent particles are packed in a column. The parameter estimation method in the Laplace transform domain presented in this work is significantly simpler, easier to use and dramatically faster than the conventional parameter estimation procedure in the time domain, which requires the repeated numerical solution of the partial differential …

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Assessment Of The Effects Of High-Pressure Operation On The Liquid-Solid Mass-Transfer Coefficient In Trickle-Bed Reactors, M. (Muthanna) H. Al-Dahhan, W. Highfill, M. Friedman Jan 1997

Assessment Of The Effects Of High-Pressure Operation On The Liquid-Solid Mass-Transfer Coefficient In Trickle-Bed Reactors, M. (Muthanna) H. Al-Dahhan, W. Highfill, M. Friedman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Trickle-Bed Reactors Are Used Widely in Industry and Are Usually Operated at High Pressure. All the Studies on Liquid-Solid Mass Transfer in Such Reactors Were Performed under Atmospheric Pressure And, Hence, the Empirical Correlations for Liquid-Solid Mass-Transfer Coefficients (K1s and K1sa) Were Developed based on Atmospheric Data. However, These Correlations Incorporate One or More of the Parameters Affected by Pressure (E.g., Liquid Holdup, Catalyst Wetting Efficiency, Pressure Drop, Gas Density). in This Work the Effects of High Pressure and High Gas Flow Rates on the Predicted Coefficients using Some of These Correlations Are Evaluated. It is Shown that There Are …

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Tomographic And Particle Tracking Studies In A Liquid-Solid Riser, Shantanu Roy, Jinwen Chen, Sailesh B. Kumar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković Jan 1997

Tomographic And Particle Tracking Studies In A Liquid-Solid Riser, Shantanu Roy, Jinwen Chen, Sailesh B. Kumar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Liquid-Solid Circulating Fluidized Bed is a Potential Reactor of Interest in a Variety of Industrial Processes, Such as Petroleum Refining, and in the Synthesis of Fine Chemicals, Petrochemicals, and Foodstuffs. Rapid Deactivation of the Solid Catalyst in These Processes Necessitates Regeneration and Regulation of the Solids into the Riser Section in Which the Principal Reaction is Accomplished. in This Study We Show that Computer-Automated Radioactive Particle Tracking (CARPT) Can Be Used to Obtain Solids Velocity Patterns in the Riser and that Backflow of Solids Exists at the Tested Liquid Velocities. Γ-Ray Computed Tomography (CT) Reveals Slightly Higher Solids Concentrations …

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Limitations And Dynamics Imposed On Multicomponent Batch Distillation By Tray Hydraulics, Keith G. Tomazi Jan 1997

Limitations And Dynamics Imposed On Multicomponent Batch Distillation By Tray Hydraulics, Keith G. Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Batch distillation models incorporating a complete set of hydraulic relations, energy balances, and tray efficiencies and simpler models based upon constant molar holdup and zero holdup (the Rayleigh equation) were used to obtain distillation curves and optimal reflux policies. The approach to hydraulic limitations was monitored in the complete hydraulic model. The results indicate that during a multicomponent batch distillation the combination of the changes in the liquid composition and liquid flow rates causes the molar holdup on the trays to vary with time and, consequently, the characteristic time constant of the trays changes. The predicted composition profiles for descriptions …

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High-Pressure Trickle-Bed Reactors: A Review, Muthanna H. Al-Dahhan, Faical Larachi, Milorad P. Dudukovic, Andre Laurent Jan 1997

High-Pressure Trickle-Bed Reactors: A Review, Muthanna H. Al-Dahhan, Faical Larachi, Milorad P. Dudukovic, Andre Laurent

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Concise Review of Relevant Experimental Observations and Modeling of High-Pressure Trickle-Bed Reactors, based on Recent Studies, is Presented. the Following Topics Are Considered: Flow Regime Transitions, Pressure Drop, Liquid Holdup, Gas-Liquid Interfacial Area and Mass-Transfer Coefficient, Catalyst Wetting Efficiency, Catalyst Dilution with Inert Fines, and Evaluation of Trickle-Bed Models for Liquid-Limited and Gas-Limited Reactions. the Effects of High-Pressure Operation, Which is of Industrial Relevance, on the Physicochemical and Fluid Dynamic Parameters Are Discussed. Empirical and Theoretical Models Developed to Account for the Effect of High Pressure on the Various Parameters and Phenomena Pertinent to the Topics Discussed Are Briefly …

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A Small-Angle Neutron Scattering Study Of Γ-Crystallins Near Their Isoelectric Point, Paul Petitt, Michael Eugene Edwards, Daniel Forciniti Jan 1997

A Small-Angle Neutron Scattering Study Of Γ-Crystallins Near Their Isoelectric Point, Paul Petitt, Michael Eugene Edwards, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this paper, a small-angle neutron scattering study of γII-crystallins near their isoelectric point is presented. The experiments were carried out using protein concentrations of 5.7-85.7 mg/ml at temperatures in the range 11-60°C. The experimental data were analyzed using an ellipsoidal model for intraparticle correlations and the mean spherical approximation for interparticle correlations. Our studies revealed that γII-crystallins have a thick hydration layer, which is possibly due to the special arrangement of polar and ionic groups on their surface. The temperature scan shows that, as a result of relatively strong attractive forces, clusters of two, three, or higher oligomers are …

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Affinity Purification Of Biologically Active Andinactive Forms Of Recombinant Human Protein C Produced In Porcine Mammary Gland, Kevin E. Van Cott, Barry Williams Department Of Chemical Engineering,Virginia Tech University, Blacksburg, Va 24061, Usa, William H. Velander, Francis C. Gwazdauskas, Tim Lee Jerome Holland Laboratory, American Red Cross, Rockville, Md 20855, Usa, Henryk Lubon, William N. Drohan Sep 1996

Affinity Purification Of Biologically Active Andinactive Forms Of Recombinant Human Protein C Produced In Porcine Mammary Gland, Kevin E. Van Cott, Barry Williams Department Of Chemical Engineering,Virginia Tech University, Blacksburg, Va 24061, Usa, William H. Velander, Francis C. Gwazdauskas, Tim Lee Jerome Holland Laboratory, American Red Cross, Rockville, Md 20855, Usa, Henryk Lubon, William N. Drohan

Papers in Biotechnology

Recombinant human protein C (rhPC) secreted in the milk of transgenic pigs was studied. 'Ikansgenes having different regulatory elements of the murine milk protein, whey acidic protein, were used with cDNA and genomic human protein C (hPC) DNA sequences to obtain lower and higher expressing animals. The cDNA pigs had a range of expression of about 0.1-0.5 g/l milk. Two different genomic hPC pig lines have expressed 0.3 and 1-2 g/l, respectively. The rhPC was first purified at yields greater than 60 per cent using a monoclonal antibody (mAb) to the activation site on the heavy chain of hPC. Subsequent …

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Measurement And Analysis Of Oxygen/Nitrogen/5a-Zeolite Adsorption Equilibria For Air Separation, Orhan Talu, Jianmin Li, Ravi Kumar, Paul M. Mathias, J. Douglas Moyer Jr, Joan M. Schork Sep 1996

Measurement And Analysis Of Oxygen/Nitrogen/5a-Zeolite Adsorption Equilibria For Air Separation, Orhan Talu, Jianmin Li, Ravi Kumar, Paul M. Mathias, J. Douglas Moyer Jr, Joan M. Schork

Chemical & Biomedical Engineering Faculty Publications

Multicomponent adsorption equilibrium data are essential for the reliable design of processes and equipment for gas separation by adsorption. We discuss techniques for the measurement and analysis of multicomponent adsorption equilibrium data, and present a comprehensive set of equilibrium data for the adsorption of oxygen and nitrogen on 5A-zeolite.

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Effect Of Antibody Orientation On Immunosorbent, Anuradha Subramanian, William H. Velander Sep 1996

Effect Of Antibody Orientation On Immunosorbent, Anuradha Subramanian, William H. Velander

Papers in Biotechnology

The impact of antibody orientation on immunosorbent efficiency was quantitatively assessed. A pH-dependent murine monoclonal antibody (Mab) against human protein C (hPC), recombinant hPC (rhPC) and two different immobilization chemistries and matrices were used as model systems. The lysyl groups of the rhPC were covalently modified with an acetic acid ester of N-hydroxysuccinimide and this modified rhPC was used as a Fab masking agent (FMA). The FMA was used to mask the antigen bind-ing regions (Fab) of the Mab prior to and during covalent immobilization. Thereafter, the residual active sites of the support were in-activated and the FMA was removed. …

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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: …

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Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh Jun 1996

Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh

Faculty Works

Purple membrane (PM, λ" role="presentation">λmax" role="presentation">max 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue (λ" role="presentation">λmax" role="presentation">max 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI−" role="presentation">− and HPO42−" role="presentation">2−4. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI−" role="presentation">− and HPO42−" role="presentation">2−4 show marked pH effect. At pH 1.0 the efficiency of …

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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 …

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