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2005

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Articles 1 - 30 of 33

Full-Text Articles in Biochemical and Biomolecular Engineering

Experimental Study Of The Solids Velocity Field In Gas-Solid Risers, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Duduković, Steven Trujillo, Timothy J. O'Hern Dec 2005

Experimental Study Of The Solids Velocity Field In Gas-Solid Risers, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Duduković, Steven Trujillo, Timothy J. O'Hern

Chemical and Biochemical Engineering Faculty Research & Creative Works

Solids Flow Dynamics in Gas-Solid Risers is Inherently Complex. Model Refinement through Experimental Validation Requires the Acquisition of Detailed Nonintrusive Measurements. in This Study, Noninvasive Computer-Automated Radioactive Particle Tracking (CARPT) is Employed to Visualize and Quantify in a Three-Dimensional Domain the Solids Dynamics and Mixing in Gas-Solid Risers. This Technique Has the Added Advantage that, along with the Derived Eulerian Solids Flow Field (Time-Average Velocity Map and Various Turbulence Parameters Such as the Reynolds Stresses, Turbulent Kinetic Energy), It Also Provides Directly the Lagrangian Description of the Solids Motion. the Solids Velocity Field Data Are Obtained in Two Different Risers …


Solids Flow Mapping In A High Pressure Slurry Bubble Column, Novica Rados, Ashfaq Shaikh, Muthanna H. Al-Dahhan Nov 2005

Solids Flow Mapping In A High Pressure Slurry Bubble Column, Novica Rados, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Successful Design and Scale-Up of Slurry Bubble Column Reactors (SBCRs) Require Proper Understanding of How Operating Conditions Affect their Flow Behavior. Presently, there is Little Information on the Flow Dynamics of Solids (E.g., Distribution of Velocities and Turbulent Parameters) in Slurry Systems that Are Operated at Industrially Relevant Conditions of High Pressure, High Superficial Gas Velocities, and High Solids Loading. Computer Automated Radio Particle Tracking (CARPT) is Widely Recognized as One of a Few Techniques that Can Be Reliably Used Even in Highly Turbulent and Opaque Slurry Flows. This Work Utilizes an Improved CARPT Technique to Investigate the Effect of …


Polymer-Mediated Synthesis Of Highly Dispersed Pt Nanoparticles On Carbon Black, Min Chen, Yangchuan Xing Sep 2005

Polymer-Mediated Synthesis Of Highly Dispersed Pt Nanoparticles On Carbon Black, Min Chen, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new method was developed to prepare highly dispersed Pt nanoparticles on carbon black to use as proton exchange membrane (PEM) fuel cell catalysts. This method involves using a polymer, poly-(vinylpyrrolidone) (PVP), to prevent particle aggregation and thereby reduce nanoparticle sizes to achieve high dispersion. It was found that Pt nanoparticles mediated by PVP are smaller than those obtained without PVP and have a narrower size distribution. Well-dispersed Pt nanoparticles with metal loadings from 5 to 35 wt % were obtained on carbon black (Vulcan XC-72R). It was found that well-dispersed Pt nanoparticles on carbon black could be synthesized at …


Enhancement Of Protein Secretion In Pichia Pastoris By Overexpression Of Protein Disulfide Isomerase, Mehmet İnan, Dinesh Aryasomayajula, Jayanta Sinha, Michael M. Meagher Sep 2005

Enhancement Of Protein Secretion In Pichia Pastoris By Overexpression Of Protein Disulfide Isomerase, Mehmet İnan, Dinesh Aryasomayajula, Jayanta Sinha, Michael M. Meagher

Papers in Biochemical Engineering

A potential vaccine candidate, Necator americanus secretory protein (Na-ASP1), against hookworm infections, has been expressed in Pichia pastoris. Na- ASP1, a 45 kDa protein containing 20 cysteines, was directed outside the cell by fusing the protein to the preprosequence of the α-mating factor of Saccharomyces cerevisiae. Most of the protein produced by single copy clones was secreted outside the cell. However, increasing gene copy number of Na-ASP1 protein in P. pastoris saturated secretory capacity and therefore, decreased the amount of secreted protein in clones harboring multiple copies of Na-ASP1 gene. Overexpression of the …


The Processing, Mechanical Properties And Bioactivity Of Zinc Based Glass Ionomer Cements, D. Boyd, Mark R. Towler Sep 2005

The Processing, Mechanical Properties And Bioactivity Of Zinc Based Glass Ionomer Cements, D. Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Ionomer Cements (GICs) for use in orthopaedics is retarded by the presence in the glass phase of aluminium, a neurotoxin. Unfortunately, the aluminium ion plays an integral role in the setting process of a GIC and its absence is likely to hinder cement formation. However, zinc oxide, a bacteriocide, can act both as a network modifying oxide and an intermediate oxide in a similar fashion to alumina and so ternary systems based on zinc silicates often have extensive regions of glass formation. The purpose of this research was to produce novel GICs based on calcium zinc …


Crosslinked Chitosan: Its Physical Properties And The Effects Of Matrix Stiffness On Chondrocyte Cell Morphology And Proliferation, Anuradha Subramanian, Hsin-Yi Lin Aug 2005

Crosslinked Chitosan: Its Physical Properties And The Effects Of Matrix Stiffness On Chondrocyte Cell Morphology And Proliferation, Anuradha Subramanian, Hsin-Yi Lin

Papers in Biotechnology

Chitosan [<(1-4)-2 amino-2-deoxy-d-glucose], the natural polyaminosaccharide derived from N-deacetylation of chitin [<(1-4)-2 acetamide-2-deoxy-d-glucose], has been shown to possess attractive biological and cell interactive properties. Recently chitosan and chitosan analogs have also been shown to support the growth and continued function of chondrocytes. In the present study, chitosan substrates are crosslinked with a func-tional diepoxide (1,4 butanediol diglycidyl ether) to alter its mechanical property, and the viability and proliferation of the canine articular chondrocytes seeded on the crosslinked surface are further assayed. Of interest is the impact of substrate stiffness on the growth and proliferation of articular canine chondrocytes. Cross linked scaffolds were also sub-jected to degradation by chitosanase to examine the impact of cross linking on enzyme- assisted degradation. The hydrophilicity and compression modulus of the crosslinked sur-faces were measured via contact-angle measurements and compression tests, respec-tively. Scanning electron microscopy (SEM) and fluorescent staining were used to ob-serve the proliferation and morphology of chondrocyte cells on noncrosslinked and crosslinked surfaces. The crosslinked chitosan was found to be nontoxic to chondrocytes and more hydrophilic. Its compression modulus and stiffness increased, which may im-prove the scaffold resistance to wear and in vivo shrinkage once implanted. The in-creased stiffness also seemed to serve as an additional mechanical stimulus to promote chondrocyte growth and proliferation. The cell morphology on crosslinked scaffolds seen by SEM and fluorescent stain was the typical chondrocytic rounded shape. The method proposed provides a nontoxic way to increase the mechanical strength of the chitosan scaffolds.


Modeling Catalytic Trickle-Bed And Upflow Packed-Bed Reactors For Wet Air Oxidation Of Phenol With Phase Change, Jing Guo, Muthanna H. Al-Dahhan Aug 2005

Modeling Catalytic Trickle-Bed And Upflow Packed-Bed Reactors For Wet Air Oxidation Of Phenol With Phase Change, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In This Study, to Simulate the Steady-State Behavior of Packed-Bed Reactors for Catalytic Wet Oxidation of Phenol, One-Dimensional (1D) Axial Dispersion Model for the Liquid Phase is Coupled with a Cell Stack Model for the Gas Phase, Providing Considerable Phase Change under the Selected Operating Conditions. the Reactor Scale Governing Equations, Reaction Kinetics Involved, and Solution Strategy Are Discussed. the Computational Approach Accounts for the Observed Catalyst Activities, Combined with Local Transport and Catalyst Wetting Effects. the Approach Selected is Shown to Be Suitable and Efficient in Dealing with the Problem in Question. Comparisons of Simulated Model Predictions and Lab …


Purification And Scale-Up Of A Recombinant Heavy Chain Fragment C Of Botulinum Neurotoxin Serotype E In Pichia Pastoris Gs115, Michael P. Dux, Rick Barent, Jayanta Sinha, Mark Gouthro, Todd Swanson, Ardis Barthuli, Mehmet İnan, John T. Ross, Leonard A. Smith, Theresa J. Smith, Robert Webb, Bonnie Loveless, Ian Henderson, Michael M. Meagher Aug 2005

Purification And Scale-Up Of A Recombinant Heavy Chain Fragment C Of Botulinum Neurotoxin Serotype E In Pichia Pastoris Gs115, Michael P. Dux, Rick Barent, Jayanta Sinha, Mark Gouthro, Todd Swanson, Ardis Barthuli, Mehmet İnan, John T. Ross, Leonard A. Smith, Theresa J. Smith, Robert Webb, Bonnie Loveless, Ian Henderson, Michael M. Meagher

Papers in Biochemical Engineering

A recombinant C-terminus heavy chain fragment from Botulinum neurotoxin serotype E (BoNT/E) is proposed as a vaccine against the serotype E neurotoxin. This fragment, rBoNTE(Hc), was produced intracellular in Pichia pastoris GS115 by a three-step fermentation process, i.e., glycerol batch phase and a glycerol fed-batch phase to achieve high cell densities, followed by a methanol fed-batch induction phase. The rBoNTE(Hc) protein was purified from the soluble fraction of cell lysates using three ion-exchange chromatography steps (SP Sepharose Fast Flow, Q Sepharose Fast Flow, Sp Sepharose High Performance) and polished with a hydrophobic charge induction chromatography step (MEP HyperCel). Method development …


Flow Distribution Characteristics Of A Gas-Liquid Monolith Reactor, Shaibal Roy, Muthanna H. Al-Dahhan Aug 2005

Flow Distribution Characteristics Of A Gas-Liquid Monolith Reactor, Shaibal Roy, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Flow Distribution Characteristics in a 0.05 M Diameter Monolith Reactor, Operated Co-Current Downward in the Taylor Flow Regime, Was Investigated and Quantified using Gamma Ray Computed Tomography (CT). the Results Indicate that the Flow Distribution is a Strong Function of Liquid Distributor Design, and Gas and Liquid Superficial Velocities. Additionally, within the Range of Gas and Liquid Superficial Velocities Investigated, a Window of Operating Condition (Gas and Liquid Velocities) Was Identified Which Resulted in a Close to Uniform Phase Distribution. © 2005 Elsevier B.V. All Rights Reserved.


Dynamic Modeling Of Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković Aug 2005

Dynamic Modeling Of Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Multicomponent, One-Dimensional, and Compartment-Based Dynamic Model Developed by Rados Et Al. (Catal. Today 2003, 79-80, 211-218) Has Been Used to Study the Performance of Slurry Bubble Columns Operated with Two Chemical Reaction Systems. One Reaction Causes Contraction in the Gas-Phase Volume, and the Other Causes Expansion. the Change in the Gas Flow Rate (Expansion or Contraction) Along the Reactor as a Result of the Chemical Reaction Kinetics is Accounted for by the overall Mass Balance of the Gas Phase Represented by Large and Small Bubbles. the Importance of Properly Accounting for the Change in the Gas Flow Rate Has …


Multicomponent Flow-Transport-Reaction Modeling Of Trickle Bed Reactors: Application To Unsteady State Liquid Flow Modulation, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković Aug 2005

Multicomponent Flow-Transport-Reaction Modeling Of Trickle Bed Reactors: Application To Unsteady State Liquid Flow Modulation, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

A One-Dimensional Reactor and Catalyst Pellet Scale Flow-Transport-Reaction Model Utilizing the Multicomponent Stefan-Maxwell Formulation for Inter- and Intraphase Transport is Developed to Simulate Unsteady State Operation in Trickle Bed Reactors. the Governing Equations and Method of Solution Are Discussed. Results Are Presented for a Model Reaction System (Hydrogenation of A-Methylstyrene) under Gas Reactant Limiting Conditions, for Liquid Flow Modulation as a Test Case of Unsteady State Operation. Model Simulations Predict that Periodic Liquid Flow Modulation Can Alter the Supply of Liquid and Gaseous Reactants to the Catalyst and Result in Reactor Performance Enhancement above that Achieved in Steady State Operation. …


Multiphase Flow Packed-Bed Reactor Modeling: Combining Cfd And Cell Network Model, Yi Jiang, Jing Guo, Muthanna H. Al-Dahhan Jul 2005

Multiphase Flow Packed-Bed Reactor Modeling: Combining Cfd And Cell Network Model, Yi Jiang, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Performance of a Multiphase Flow Packed-Bed Reactor Was Evaluated by a Mixing-Cell Network Model in Which the Cell-Scale Flow Field Information Was Provided by Multifluid CFD Modeling. Such a Sequentially Combined Modeling Approach Was Able to Show the Heterogeneity of Liquid Species Conversion in a Trickle-Bed Reactor that Has Been Confirmed by in Situ Magnetic Resonance Experiments. 1 a Conventional Plug Flow Model (PFM) and Axial Dispersion Model (ADM) Showed Either overpredicted or Underpredicted Conversion Compared with the Conversion Computed from the CFD-Cell Network Model. Preliminary Case Study Has Shown the Ability of the CFD-Cell Network Model in Assessing …


Modeling And Scale-Up Of Mixing- And Temperature-Sensitive Chemical Reactions, Gary Patterson Jul 2005

Modeling And Scale-Up Of Mixing- And Temperature-Sensitive Chemical Reactions, Gary Patterson

Chemical and Biochemical Engineering Faculty Research & Creative Works

A review of published measurements of yield for complex chemical reactions in mixed reactors of various types and methods of modeling and simulating such reactions for the purpose of reactor scale-up shows the extent of progress that has been made. Reaction kinetics for very fast competitive reactions are usually difficult and expensive to determine. Many reaction processes must be scaled up from bench- and/or pilot-scale experiments that produce yield data under various mixing conditions. the variables that strongly affect the yield results are the reaction types and their rates, feed point in the reactor, feed injection velocity and scale, mixing …


The Phosphoglycolate Phosphatase Gene And The Mutation In The Phosphoglycolate Phosphatase-Deficient Mutant (Pgp1-1) Of Chlamydomonas Reinhardtii, Kensaku Suzuki, Hidenobu Uchida, Tarlan G. Mamedov Jul 2005

The Phosphoglycolate Phosphatase Gene And The Mutation In The Phosphoglycolate Phosphatase-Deficient Mutant (Pgp1-1) Of Chlamydomonas Reinhardtii, Kensaku Suzuki, Hidenobu Uchida, Tarlan G. Mamedov

Papers in Biochemical Engineering

The sequences of the phosphoglycolate phosphatase (PGPase) gene Pgp1 and the 5′-upstream region from Chlamydomonas reinhardtii wildtype 2137 and the pgp1-1 mutant N142 that lacks the activity of PGPase (PGP1) were determined. The comparison revealed the alteration of a G to A at position 98 relative to the start codon. This destroyed the “GT” splice donor site at the beginning of the first intron of this gene, resulting in an extension of the first exon to 49 translatable codons followed by a stop codon, containing the codons corresponding to whole transit peptide for the chloroplast stroma and the first four …


Uv-Vis -Infrared Optical And Afm Study Of Spin-Cast Chitosan Films, W H. Nosal, D. W. Thompson, Sabyasachi Sarkar, Anuradha Subramanian, John A. Woollam, L Yan Jun 2005

Uv-Vis -Infrared Optical And Afm Study Of Spin-Cast Chitosan Films, W H. Nosal, D. W. Thompson, Sabyasachi Sarkar, Anuradha Subramanian, John A. Woollam, L Yan

Papers in Biotechnology

Optical properties OS spin-cast chitosan films have been determined in the infrared, visible, and ultraviolet region or the spectrum ~tsing spectroscopic ellipsometry. Optical constants for the Vvis-near IR spectra from 130 to 1700 nm were determined using Cauchy dispersion forms com-bined with Lorentzian oscillator models in the absorptive shorler wavelength regions. Infrared ndex of refraction and extinction coefficients from 750 to 4000cm-' were determined using ellip-sometric data fits to dispersion models based on harmonic oscillators. This modeling determined that optical onisotropy was present and measurable over all wavelength regions of ellipsomctric data. To obtain information on the micro- and nano-scale …


Chromatographic Purification Of Mabs With Non-Affinity Supports, Anuradha Subramanian Jun 2005

Chromatographic Purification Of Mabs With Non-Affinity Supports, Anuradha Subramanian

Papers in Biotechnology

The introduction of new protein-based therapeutics such as monoclonal antibodies (MAbs), MAb-based vaccines, growth factors and plasma proteins implies the need to study, characterize, and purify. The separation step is likely to be a bottleneck and cost-effective technology will be needed to rectify it. The currently prevalent matrices for chromatographic separation of immunoglobulins (Igs) are based on Protein A or its recombinant versions (Protein G). They display excellent selectivity and specificity, but are expensive. A Protein A matrix costs $8,000 to 12,000 per L-resin. The typical production column volume is 100 L. The million-dollar matrix is far more expensive than …


Liquid Saturation And Gas-Liquid Distribution In Multiphase Monolithic Reactors, Tobias Bauer, Shaibal Roy, Ruediger Lange, Muthanna H. Al-Dahhan Jun 2005

Liquid Saturation And Gas-Liquid Distribution In Multiphase Monolithic Reactors, Tobias Bauer, Shaibal Roy, Ruediger Lange, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Monolith Bed is One of the Promising Catalytic Reactors for a Number of Chemical Gas-Liquid-Solid Processes. in the Present Work, Liquid Saturations for Five Different Monoliths Have Been Investigated Experimentally in a Cold-Flow Unit with a Reactor Diameter of 5.0 Cm. the Influences of Gas and Liquid Flow Rates and of the Direction of Two-Phase Flow on Liquid Saturation Were Examined. the Results Indicate that the Direction of Flow Has No Significant Influence on Liquid Saturation for Proper Gas-Liquid Distribution. the Experimental Results Are in Good Agreement with Predictions of the Drift Flux Model using the Distribution Parameter Proposed …


Modeling Of Immunoglobulin Uptake By N,N,N′,N′-Ethylenediaminetetramethylenephosphonic Acid-Modified Zirconia Particles Under Static And Dynamic Conditions, Sabyasachi Sarkar, Anuradha Subramanian May 2005

Modeling Of Immunoglobulin Uptake By N,N,N′,N′-Ethylenediaminetetramethylenephosphonic Acid-Modified Zirconia Particles Under Static And Dynamic Conditions, Sabyasachi Sarkar, Anuradha Subramanian

Papers in Biotechnology

A matrix developed from N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid-modified zirconia beads (further referred to as r_PEZ); 25–38 μm in diameter and with a pore size of 22 ± 3 nm, was utilized for the separation of immunoglobulins (Igs). r_PEZ has been shown to bind to various Igs originating from a wide variety of species. To understand the mechanisms controlling the uptake of Igs by r_PEZ, static protein uptake experiments were carried out. The protein uptake profiles were further modeled with a kinetic rate constant model. Individual studies were undertaken for human immunoglobulin A, G and M (HIgA, HIgG and HIgM). The kinetic rate …


The Use Of Confocal Laser Scanning Microscopy To Study The Transport Of Biomacromolecules In A Macroporous Support, Anuradha Subramanian, Jennifer Hommerding Apr 2005

The Use Of Confocal Laser Scanning Microscopy To Study The Transport Of Biomacromolecules In A Macroporous Support, Anuradha Subramanian, Jennifer Hommerding

Papers in Biotechnology

Large-pore materials or supports resembling polymer conduits are used as packing material in chromatographic operations. Our ongoing research has shown that, when modified with peptides or ligands, chitosan beads that are 800 m in diameter and have 3.5% solids can be used as matrices in bioseparations. The goal of the present study is to evaluate the transport properties of biomolecules in the modified chitosan beaded matrices. Batch uptake experiments with fluorescently tagged pure human IgG, human IgA and human IgM were conducted to visualize the distribution of binding sites throughout the bead as well as to evaluate restrictions to diffusion, …


Identification Of The Mass Transfer Mechanisms Involved In The Transport Of Human Immunoglobulin - G In N,N,N',N' -Ethylnediaminetetramenthylenephosphonic Acid Modified Zirconia, Sabyasachi Sarkar, Perer W. Carr, Anuradha Subramanian Apr 2005

Identification Of The Mass Transfer Mechanisms Involved In The Transport Of Human Immunoglobulin - G In N,N,N',N' -Ethylnediaminetetramenthylenephosphonic Acid Modified Zirconia, Sabyasachi Sarkar, Perer W. Carr, Anuradha Subramanian

Papers in Biotechnology

Zirconia particles modified with N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid (EDTPA), further referred to as r_PEZ, were studied as a support material for use in chromatography. Our previous studies have demonstrated the utility of r_PEZ in the separation of immunoglobulins from biological fluids. In the present study we sought to understand the underlying factors and identify the rate-limiting mechanisms that govern the transport of biomolecules in r_PEZ. Pulse injection techniques were used to elucidate the individual mass transfer parameters. Elution profiles obtained under retained and unretained conditions were approximated by the Gaussian equation and the corresponding HETP contributions were estimated. The dependence of …


Flow Pattern Visualization In A Mimic Anaerobic Digester Using Cfd, Mehul S. Vesvikar, Muthanna H. Al-Dahhan Mar 2005

Flow Pattern Visualization In A Mimic Anaerobic Digester Using Cfd, Mehul S. Vesvikar, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three-Dimensional Steady-State Computational Fluid Dynamics (CFD) Simulations Were Performed in Mimic Anaerobic Digesters to Visualize their Flow Pattern and Obtain Hydrodynamic Parameters. the Mixing in the Digester Was Provided by Sparging Gas at Three Different Flow Rates. the Gas Phase Was Simulated with Air and the Liquid Phase with Water. the CFD Results Were First Evaluated using Experimental Data Obtained by Computer Automated Radioactive Particle Tracking (CARPT). the Simulation Results in Terms of overall Flow Pattern, Location of Circulation Cells and Stagnant Regions, Trends of Liquid Velocity Profiles, and Volume of Dead Zones Agree Reasonably Well with the Experimental Data. …


Identification And Expression Analysis Of Two Inorganic C-And N-Responsive Genes Encoding Novel And Distinct Molecular Forms Of Eukaryotic Phosphoenolpyruvate Carboxylase In The Green Microalga Chlamydomonas Reinhardtii, Tarlan G. Mamedov, Eric R. Moellering, Raymond Chollet Mar 2005

Identification And Expression Analysis Of Two Inorganic C-And N-Responsive Genes Encoding Novel And Distinct Molecular Forms Of Eukaryotic Phosphoenolpyruvate Carboxylase In The Green Microalga Chlamydomonas Reinhardtii, Tarlan G. Mamedov, Eric R. Moellering, Raymond Chollet

Papers in Biochemical Engineering

Phosphoenolpyruvate carboxylase (PEPC [Ppc]) has been previously purified and characterized in biochemical and immunological terms from two green microalgae, Chlamydomonas reinhardtii and Selenastrum minutum. The findings indicate that these algae possess at least two distinct PEPC enzyme-forms, homotetrameric Class1 and heteromeric Class-2 that differ significantly from each other and their plant and prokaryotic counterparts. Surprisingly, however, green-algal PEPC has been unexplored to date in molecular terms. This study reports the molecular cloning of the two Ppc genes in C. reinhardtii (CrPpc1, CrPpc2), each of which is transcribed in vivo and encodes a fully active, recombinant PEPC that lacks the regulatory, …


Crystallization And Preliminary X-Ray Analysis Of Na-Asp-1, A Multi-Domain Pathogenesis-Related-1 Protein From The Human Hookworm Parasite Necator Americanus, Mehmet İnan, Oluwatoyin A. Asojo, Alex Lucas, Rick Barent, Jicai Huang, Brad Plantz, Amber Swanson, Mark Gouthro, Michael M. Meagher, Peter J. Hotez Mar 2005

Crystallization And Preliminary X-Ray Analysis Of Na-Asp-1, A Multi-Domain Pathogenesis-Related-1 Protein From The Human Hookworm Parasite Necator Americanus, Mehmet İnan, Oluwatoyin A. Asojo, Alex Lucas, Rick Barent, Jicai Huang, Brad Plantz, Amber Swanson, Mark Gouthro, Michael M. Meagher, Peter J. Hotez

Papers in Biochemical Engineering

Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis related- 1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na …


Experimental Investigation Of The Hydrodynamics In A Liquid-Solid Riser, Shantanu Roy, Abdenour Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Mar 2005

Experimental Investigation Of The Hydrodynamics In A Liquid-Solid Riser, Shantanu Roy, Abdenour Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Liquid-Solid Fluid Dynamics Has Been Investigated in a 6-In. (0.15 M) "Cold-Flow" Circulating Fluidized Bed Riser using Non-Invasive Flow Monitoring Methods. Gamma-Ray Computed Tomography (CT) Was Used to Measure the Time-Averaged Cross-Sectional Solids Volume Fraction Distributions at Several Elevations. the Time-Averaged Mean and "Fluctuating" Solids Velocity Fields Were Quantified using the Computer-Automated Radioactive Particle Tracking (CARPT) Technique. the Experimental Equipment, Protocol of Implementation, and Data Analysis Have Been Discussed Briefly, with Particular Emphasis on the Specific Features in the Use of These Techniques for Studying High-Density Turbulent Flows as in a Liquid-Solid Riser. the Experimental Study Examines Nine Operating Conditions, …


Catalytic Wet Air Oxidation Of Phenol In Concurrent Downflow And Upflow Packed-Bed Reactors Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan Feb 2005

Catalytic Wet Air Oxidation Of Phenol In Concurrent Downflow And Upflow Packed-Bed Reactors Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Experimental Study is Presented for Comparing the Behavior of a Packed Bed Reactor in the Catalytic Liquid-Phase Oxidation of Aqueous Phenol with Two Modes of Operation, Downflow and Upflow. the Operating Parameters Investigated Included Temperature, Reactor Pressure, Gas Flowrate, Liquid Hourly Space Velocity and Feed Concentration. Because of the Completely Wetted Catalyst, the Upflow Reactor Generally Performs Better for High Pressures and Low Feed Concentrations When the Liquid Reactant Limitation Controls the Rate. the Interaction between the Reactor Hydrodynamics, Mass Transfer, and Reaction Kinetics is Discussed. for Both Operation Modes, Complete Phenol Removal and Significant Total Organic Carbon (TOC) …


Fractionation Of Cell Mixtures Using Acoustic And Laminar Flow Fields, Manoj Kumar, Donald L. Feke, Joanne M. Belovich Jan 2005

Fractionation Of Cell Mixtures Using Acoustic And Laminar Flow Fields, Manoj Kumar, Donald L. Feke, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A fractionation method applicable to different populations of cells in a suspension is reported. The separation was accomplished by subjecting the suspension to a resonant ultrasonic field and a laminar flow field propagating in orthogonal directions within a thin, rectangular chamber. Steady, laminar flow transports the cell suspension along the chamber, while the ultrasonic field causes the suspended cells to migrate to the mid-plane of the chamber at rates related to their size and physical properties. A thin flow splitter positioned near the outlet divides the effluent cell suspension into two product streams, thereby allowing cells that respond faster to …


Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander Jan 2005

Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander

Papers in Biotechnology

Transgenic animals secreting individual chains and assembled fibrinogen were produced to evaluate the capacity of the mammary gland for maximizing assembly, glycosylation and secretion of recombinant human fibrinogen (rhfib). Transgenes were constructed from the 4.1 kbp murine Whey Acidic Protein promoter (mWAP) and the three cDNAs coding for the Aα,Bβ and γ fibrinogen chains. Transgenic mice secreted fully assembled fibrinogen into milk at concentrations between 10 and 200 μg/ml, with total secretion of subunits approaching 700 μ g/ml in milk. Partially purified fibrinogen was shown to form a visible and stable clot after treatment with human thrombin and factor XIII. …


Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander Jan 2005

Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander

Papers in Biotechnology

Transgenic animals secreting individual chains and assembled fibrinogen were produced to evaluate the capacity of the mammary gland for maximizing assembly, glycosylation and secretion of recombinant human fibrinogen (rhfib). Transgenes were constructed from the 4.1 kbp murine Whey Acidic Protein promoter (mWAP) and the three cDNAs coding for the Aα,Bβ and γ fibrinogen chains. Transgenic mice secreted fully assembled fibrinogen into milk at concentrations between 10 and 200 μg/ml, with total secretion of subunits approaching 700 μ g/ml in milk. Partially purified fibrinogen was shown to form a visible and stable clot after treatment with human thrombin and factor XIII. …


Preparation And Evaluation Of The Electrospun Chitosan/Peo Fibers For Potential Applications In Cartilage Tissue Engineering, Anuradha Subramanian, David Vu, Gustavo F. Larsen, Hsin Yii Lin Jan 2005

Preparation And Evaluation Of The Electrospun Chitosan/Peo Fibers For Potential Applications In Cartilage Tissue Engineering, Anuradha Subramanian, David Vu, Gustavo F. Larsen, Hsin Yii Lin

Papers in Biotechnology

Fibrous materials have morphological similarities to natural cartilage extracellular matrix and have been considered as candidate for bone tissue engineering scaffolds. In this study, we have evaluated a novel electrospun chitosan mat composed of oriented sub-micron fibers for its tensile property and biocompatibility with chondrocytes (cell attachment, proliferation and viability). Scanning electronic microscope images showed the fibers in the electrospun chitosan mats were indeed aligned and there was a slight cross-linking between the parent fibers. The electrospun mats have significantly higher elastic modulus (2.25 MPa) than the cast films (1.19 MPa). Viability of cells on the electrospun mat was 69% …


Physico-Chemical Characteristics Of European Pulverized Coal Combustion Fly Ashes, N. Moreno, X. Querol, J. M. Andrés, K. Stanton, Mark R. Towler, H. Nugteren, M. Janssen-Jurkovicová, R. Jones Jan 2005

Physico-Chemical Characteristics Of European Pulverized Coal Combustion Fly Ashes, N. Moreno, X. Querol, J. M. Andrés, K. Stanton, Mark R. Towler, H. Nugteren, M. Janssen-Jurkovicová, R. Jones

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fly ashes sourced from European pulverized coal burning power plants (from Spain, The Netherlands, Italy and Greece) were characterized in terms of their chemical composition, mineralogy and physical properties. The amount and composition of the glass present in the ashes were also determined. The materials analyzed have very different compositions and were selected with a view to determining their suitability for different applications and for further studies on applications. The results were compared to the literature to determine their similarities to UK coal fly ashes. Chemical analysis has enabled the categorization of the ashes based on their oxide contents. Devitrification …