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

Chemical Engineering Commons™

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

Biochemical and Biomolecular Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1141 - 1170 of 1431

Full-Text Articles in Chemical Engineering

Phase Distribution In A High Pressure Slurry Bubble Column Via A Single Source Computed Tomography, Novica Rados, Ashfaq Shaikh, Muthanna H. Al-Dahhan Jan 2005

Phase Distribution In A High Pressure Slurry Bubble Column Via A Single Source Computed Tomography, Novica Rados, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Due to their Numerous Advantages, Slurry Bubble Column Reactors (SBCR) Are Gaining Wide Importance in the Petroleum, Petrochemical, Chemical, and Biochemical Industries. Most Previous Literature Studies on the Fluid Dynamics and the Phase Holdup Distribution in SBCR Are Limited to Low Superficial Gas Velocity, Low Solids Loading, and the Atmospheric Pressure. Moreover, the Presence of a Solids Phase Poses Difficulties in Probe Measurement Techniques Such as Pitot Tube and Optical Probe and See through Measurement Techniques Such as Particle Image Velocimetry (PIV), Laser Doppler Velocimetry (LDV). Single Source Γ-Ray Computed Tomography (CT) Has Been Used to Measure Cross-Sectional Phase Holdup …

Go to article

Ranque–Hilsch Vortex Tube Thermocycler For Fast Dna Amplification And Real-Time Optical Detection, Ryan J. Ebmeier, Scott E. Whitney, Amitabha Sarkar, Michael Nelson, Nisha Padhye, George Gogos, Hendrik J. Viljoen Dec 2004

Ranque–Hilsch Vortex Tube Thermocycler For Fast Dna Amplification And Real-Time Optical Detection, Ryan J. Ebmeier, Scott E. Whitney, Amitabha Sarkar, Michael Nelson, Nisha Padhye, George Gogos, Hendrik J. Viljoen

Papers in Biochemical Engineering

An innovative polymerase chain reaction (PCR) thermocycler capable of performing real-time optical detection is described below. This device utilizes the Ranque–Hilsch vortex tube in a system to efficiently and rapidly cycle three 20 mL samples between the denaturation, annealing, and elon-gation temperatures. The reaction progress is displayed real-time by measuring the size of a fluo-rescent signal emitted by SYBR green/double-stranded DNA complexes. This device can produce significant reaction yields with very small amounts of initial DNA, for example, it can amplify 0.25 fg (,5 copies) of a 96 bp bacteriophage l-DNA fragment 2.731011-fold by performing 45 cycles in less than …

Go to article

Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Methylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-T, Jayanta Sinha, Bradley A. Plantz, Mehmet Inan, Michael Meagher Dec 2004

Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Methylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-T, Jayanta Sinha, Bradley A. Plantz, Mehmet Inan, Michael Meagher

Papers in Biotechnology

It was observed that during fermentative production of recombinant ovine interferon-H (r-oIFN-H ) in Pichia pastoris, a secreted recombinant protein, the protein was degraded increasingly after 48 h of induction and the rate of degradation increased towards the end of fermentation at 72 h, when the fermentation was stopped. Proteases, whose primary source was the vacuoles, was found in in-creasing levels in the cytoplasm and in the fermentation broth after 48 h of induction and reached maximal values when the batch was completed at 72 h. Protease levels at various cell fractions as well as in the culture supernatant …

Go to article

Optimization Of Batch Reactions In Series With Uncertainty, Keith G. Tomazi Nov 2004

Optimization Of Batch Reactions In Series With Uncertainty, Keith G. Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Certain types of chemical reactions, such as the global deprotection of a polypeptide, are extremely complex. As a result, it may be very difficult or expensive to develop accurate models of these chemical reactions. Without a satisfactory kinetic model for the reaction, it is difficult to develop an optimum operating policy that will maximize the profit. Stochastic optimization is applied in this work to an example process step to obtain the optimum reaction temperature and reaction time. In the case of the "here and now" problem, the optimal conditions are a lower reaction temperature and a longer reaction time than …

Go to article

Monoliths As Multiphase Reactors: A Review, Shaibal Roy, Tobias Bauer, Muthanna H. Al-Dahhan, Peter Lehner, Thomas Turek Nov 2004

Monoliths As Multiphase Reactors: A Review, Shaibal Roy, Tobias Bauer, Muthanna H. Al-Dahhan, Peter Lehner, Thomas Turek

Chemical and Biochemical Engineering Faculty Research & Creative Works

Monolith Reactors Are Being Studied as a Replacement for Conventional Multiphase Reactors Such as Trickle-Bed Reactors, Slurry Reactors, and Slurry Bubble Column Reactors for Gas-Liquid-Solid Reactions. Reactors with Monolith Catalyst Packing Have Been Found to Be Hydrodynamically Superior to Existing Industrial Reactors. This Review Covers Multiphase Reactions Carried Out in Monolith Reactors by Various Researchers. It First Defines the Monolith Reactor and Looks into the Geometrical Aspects of Monolith. the Section Dealing with Hydrodynamics Reviews Pressure Drop, Phase Holdup, Flow Distribution, and Dispersion Characteristics. This Study Also Considers the Tools Used to Characterize the Hydrodynamic Parameters and their Typical Values. …

Go to article

Quantification Of Solids Flow In A Gas-Solid Riser: Single Radioactive Particle Tracking, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Dudukovic Nov 2004

Quantification Of Solids Flow In A Gas-Solid Riser: Single Radioactive Particle Tracking, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Solids in Risers of Circulating Fluidized Beds (CFB) Exhibit Local Backflow and Recirculation. Measurement of the Concentration-Time Response to an Impulse Injection of Tracer, Even at Two Elevations Cannot Determine the Residence Time Distribution (RTD) of Solids Uniquely. Hence, Evaluation of RTD in Risers from Conventional Tracer Responses is Difficult and Often Not Possible. in Addition, Estimating the Solids Circulation Rate in These Closed Loop Systems, is a Non-Trivial Problem. in This Work, a Single Radioactive Particle in the CFB Loop is Tracked during its Multiple Visits to the Riser And, by Invoking Ergodicity, Solids Circulation Rate, Accurate Solids RTD …

Go to article

Liquid Holdup And Pressure Drop In The Gas-Liquid Cocurrent Downflow Packed-Bed Reactor Under Elevated Pressures, Jing Guo, Muthanna H. Al-Dahhan Nov 2004

Liquid Holdup And Pressure Drop In The Gas-Liquid Cocurrent Downflow Packed-Bed Reactor Under Elevated Pressures, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Experimental Investigation of the Residence Time Distribution, Liquid Holdup, and Pressure Drop in a Gas-Liquid Downflow Packed Bed Reactor with Porous Particles Operated under Elevated Pressures is Presented. the Effects of the Two-Phase Flow Rates and Reactor Pressures on the External Liquid Holdup and Pressure Drop Are Discussed. a Mechanistic Model, Which Accounts for the Interaction between the Gas and Liquid Phases by Incorporating the Shear and Velocity Slip Factors between Phases, is Employed to Predict the External Liquid Holdup and Pressure Drop for the Experimentally Covered Flow Regime. the Involved Parameters, Such as Shear and Velocity Slip Factors …

Go to article

Exergy Use In Bioenergetics, Yaşar Demirel Nov 2004

Exergy Use In Bioenergetics, Yaşar Demirel

Papers in Analytical Chemistry

Every developed and adapted biological system extracts useful energy from outside, converts, stores it, and uses for muscular contraction, substrate transport, protein synthesis, and other energy utilizing processes. This energy management in a living cell is called the bioenergetics, and the useful energy is the exergy, which is destroyed in every irreversible process because of the entropy production. The converted exergy is the adenosine triphosphate (ATP) produced through the oxidative phosphorylation coupled to respiration in which the exergy originates from oxidation of reducing equivalents of nutrients. A living cell uses the ATP for all the energy demanding activities; it has …

Go to article

Production And Purification Of A Chimeric Monoclonal Antibody Against Botulinum Neurotoxin Serotype A , Mark C. Mowry, Michael Meagher Lead Investigator, Leonard Smith, Anuradha Subramanian Oct 2004

Production And Purification Of A Chimeric Monoclonal Antibody Against Botulinum Neurotoxin Serotype A , Mark C. Mowry, Michael Meagher Lead Investigator, Leonard Smith, Anuradha Subramanian

Papers in Biotechnology

Production of recombinant antibodies against botulinum neurotoxin is necessary for the development of a post-exposure treatment. CHO-DG44 cells were transfected with a plasmid encoding the light and heavy chains of a chimeric monoclonal antibody (S25) against botulism neurotoxin serotype A. Stable cell lines were obtained by dilution cloning and clones were shown to produce nearly equivalent levels of light and heavy chain antibody by an enzyme-linked immunosorbent assay (ELISA). In suspension culture, cells produced 35 μg/ml of chimeric antibody after 6 days, corresponding to a specific antibody productivity of 3.1 pg/cell/day. A method for the harvest and recovery of an …

Go to article

Haemophilic Factors Produced By Transgenic Livestock: Abundance That Can Enable Alternative Therapies Worldwide, Kevin E. Van Cott, Paul E. Monahan, Timothy C. Nichols, William H. Velander Oct 2004

Haemophilic Factors Produced By Transgenic Livestock: Abundance That Can Enable Alternative Therapies Worldwide, Kevin E. Van Cott, Paul E. Monahan, Timothy C. Nichols, William H. Velander

Papers in Biotechnology

Haemophilia replacement factors, both plasma-derived and recombinant, are in relatively short supply and are high-cost products. This has stymied the study and development of alternative methods of administration of haemophilia therapy even in the most economically advanced countries, owing to the large amounts of material needed because bioabsorption and bioavailability of haemophilic factors can be less than 10% when using non-intravenous routes of delivery. There is therefore a need to increase access to therapy worldwide by decreasing the cost and increasing the abundance so that therapy can be achieved through simplified, alternative delivery methods. Transgenic livestock have been used to …

Go to article

Determining Suitability Of A Fly Ash For Silica Extraction And Zeolite Synthesis, Natàlia Moreno, Xavier Querol, Angel López-Soler, José Manuel Andres, Maria Janssen, Henk Nugteren, Mark R. Towler, Kenneth Stanton Sep 2004

Determining Suitability Of A Fly Ash For Silica Extraction And Zeolite Synthesis, Natàlia Moreno, Xavier Querol, Angel López-Soler, José Manuel Andres, Maria Janssen, Henk Nugteren, Mark R. Towler, Kenneth Stanton

Chemical and Biochemical Engineering Faculty Research & Creative Works

Zeolitic material is obtained from fly ash both by direct conversion of the ash or from SiO2 extracts obtained from fly ash. This study focuses on determining the suitability of a fly ash for SiO2 extraction and for zeolite synthesis by direct conversion. The SiO2 extraction experiments from different fly ashes show that the main parameters governing the SiO2 extraction are: (a) a high bulk SiO2 content (> 52%, for obtaining an extraction yield of 100 g SiO2 kg-1) in the starting fly ash, (b) a high proportion (> 55%) of the bulk SiO …

Go to article

Investigation Into The Ultrasonic Setting Of Glass Ionomer Cements : Part Ii Setting Times And Compressive Strengths, E. Twomey, Mark R. Towler, C. M. Crowley, J. Doyle, S. Hampshire Jul 2004

Investigation Into The Ultrasonic Setting Of Glass Ionomer Cements : Part Ii Setting Times And Compressive Strengths, E. Twomey, Mark R. Towler, C. M. Crowley, J. Doyle, S. Hampshire

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ultrasonic setting of glass ionomer cements (GIC) was discussed. It was observed that the ultrasonic setting resulted in improvements of compressive strength. An increase in the PAA molecular weight from PAA50 to PAA200 resulted in an increase in the strength, but with a further increase in the PAA molecular weight to PAA450, there was a reduction in the strength. Results show that the strength of the ultrasonically set materials after 1 day were close to the values for the 7 days chemically set samples.

Go to article

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo Jun 2004

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

Go to article

Optimization Of Cell Density And Dilution Rate In Pichia Pastoris Continuous Fermentations For Production Of Recombinant Proteins, Wenhui Zhang, Chih-Ping Liu, Mehmet Inan, Michael M. Meagher Jun 2004

Optimization Of Cell Density And Dilution Rate In Pichia Pastoris Continuous Fermentations For Production Of Recombinant Proteins, Wenhui Zhang, Chih-Ping Liu, Mehmet Inan, Michael M. Meagher

Papers in Biomolecular Engineering

This paper provides an approach for optimizing the cell density (Xc) and dilution rate (D) in a chemostat for a Pichia pastoris continuous fermentation for the extracellular production of a recombinant protein, interferon τ (INF-τ). The objective was to maximize the volumetric productivity (Q, mg INF-τ I-1 h-1), which was accomplished using response surface methodology (RSM) to model the response of Q as a function of Xc and D within the ranges 150 ≤ Xc ≤ 450 g cells (wet weight) l-1 and 0.1 μm ≤ D …

Go to article

The Influence Of Strontium Substitution In Fluorapatite Glasses And Glass-Ceramics, R. G. Hill, A. Stamboulis, R. V. Law, A. Clifford, Mark R. Towler, C. Crowley May 2004

The Influence Of Strontium Substitution In Fluorapatite Glasses And Glass-Ceramics, R. G. Hill, A. Stamboulis, R. V. Law, A. Clifford, Mark R. Towler, C. Crowley

Chemical and Biochemical Engineering Faculty Research & Creative Works

Strontium is often substituted for calcium in order to confer radio-opacity in glasses used for dental cements, Biocomposites and bio glass-ceramics. The present paper investigates the influence of substituting strontium for calcium in a glass of the following composition: 4.5SiO23Al2O 31.5P2O53CaO2CaF2, having a Ca:P ratio of 1.67 corresponding to calcium fluorapatite (Ca5(PO 4)3F). The glasses were characterized by magic angle spinning nuclear magnetic resonance (MAS-NMR), by differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD). The 29Si, 27Al and 31P NMR spectra for the glasses with …

Go to article

Growth And Transport Properties Of Complementary Germanium Nanowire Field Effect Transistors, Andrew B. Greytak, Lincoln J. Lauhon, Mark S. Gudiksen, Charles M. Lieber May 2004

Growth And Transport Properties Of Complementary Germanium Nanowire Field Effect Transistors, Andrew B. Greytak, Lincoln J. Lauhon, Mark S. Gudiksen, Charles M. Lieber

Faculty Publications

n- and p-type Ge nanowires were synthesized by a multistep process in which axial elongation, via vapor–liquid–solid (VLS) growth, and doping were accomplished in separate chemical vapor deposition steps. Intrinsic, single-crystal, Ge nanowires prepared by Au nanocluster-mediated VLS growth were surface-doped in situ using diborane or phosphine, and then radial growth of an epitaxial Ge shell was used to cap the dopant layer. Field-effect transistors prepared from these Ge nanowires exhibited on currents and transconductances up to 850 µA/µm and 4.9 µA/V, respectively, with device yields of >85%.

Go to article

Characterisation Of The Glass Fraction Of A Selection Of European Coal Fly Ashes, J. Henry, Mark R. Towler, K. T. Stanton, X. Querol, N. Moreno May 2004

Characterisation Of The Glass Fraction Of A Selection Of European Coal Fly Ashes, J. Henry, Mark R. Towler, K. T. Stanton, X. Querol, N. Moreno

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fly ash largely consists of the inorganic content of coal that remains after combustion. The crystalline phases present in fly ash may form upon cooling of a molten alumino-silicate glass. This view is supported by the spherical shape of many fly ash particles, inferring that they have gone through a viscous fluid state. The amorphous content in fly ash is believed to dominate reactivity behaviour, under both alkaline and acid conditions, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass makes the bond breakage easier. It …

Go to article

A Sequential Approach To Modeling Catalytic Reactions In Packed-Bed Reactors, Jing Guo, Muthanna H. Al-Dahhan May 2004

A Sequential Approach To Modeling Catalytic Reactions In Packed-Bed Reactors, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Sequential Modeling Approach is Proposed to Simulate Catalytic Reactions in Packed-Bed Reactors. the Hydrogenation of Alpha-Methylstyrene and Wet Oxidation of Phenol Are Selected as Studied Cases. the Modeling Scheme Combines a Reactor Scale Axial Dispersion Model with a Pellet Scale Model. Without Involving Any Fitting Parameters, Such an Approach Accounts for the Non-Linear Reaction Kinetics Expression and Different Types of Pellet-Liquid Wetting Contact. to Validate the Developed Modeling Scheme and the Parallel Approach Reported in the Literature, the Experimental Observations for Hydrogenation of Alpha-Methylstyrene to Cumene Have Been Employed. the Predicted Results by Both Approaches Agree Reasonably with the …

Go to article

Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Methylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-Τ, Mehmet İnan, Michael M. Meagher, Bradley A. Plantz, Jayanta Sinha Mar 2004

Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Methylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-Τ, Mehmet İnan, Michael M. Meagher, Bradley A. Plantz, Jayanta Sinha

Papers in Biochemical Engineering

It was observed that during fermentative production of recombinant ovine interferon-τ (r-oIFN-τ) in Pichia pastoris, a secreted recombinant protein, the protein was degraded increasingly after 48 h of induction and the rate of degradation increased towards the end of fermentation at 72 h, when the fermentation was stopped. Proteases, whose primary source was the vacuoles, was found in increasing levels in the cytoplasm and in the fermentation broth after 48 h of induction and reached maximal values when the batch was completed at 72 h. Protease levels at various cell fractions as well as in the culture supernatant were …

Go to article

Analyzing And Modeling Of Photobioreactors By Combining First Principles Of Physiology And Hydrodynamics, Hu Ping Luo, Muthanna H. Al-Dahhan Feb 2004

Analyzing And Modeling Of Photobioreactors By Combining First Principles Of Physiology And Hydrodynamics, Hu Ping Luo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Mixing in Photobioreactors is Known to Enhance Biomass Productivity Considerably, and Flow Dynamics Play a Significant Role in the Reactor's Performance, as They Determine the Mixing and the Cells' Movement. in This Work We Focus on Analyzing the Effects of Mixing and Flow Dynamics on the Photobioreactor Performance. based on Hydrodynamic Findings from the CARPT(Computer Automated Radioactive Particle Tracking) Technique, a Possible Mechanism for the Interaction between the Mixing and the Physiology of Photosynthesis is Presented, and the Effects of Flow Dynamics on Light Availability and Light Intensity Fluctuation Are Discussed and Quantitatively Characterized. Furthermore, a Dynamic Modeling Approach is …

Go to article

Retention And Viability Characteristics Of Mammalian Cells In An Acoustically Driven Polymer Mesh, Zhaowei Wang, Paul Grabenstetter, Donald L. Feke, Joanne M. Belovich Jan 2004

Retention And Viability Characteristics Of Mammalian Cells In An Acoustically Driven Polymer Mesh, Zhaowei Wang, Paul Grabenstetter, Donald L. Feke, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A processing approach for the collection and retention of mammalian cells within a high porosity polyester mesh having millimeter-sized pores has been studied. Cell retention occurs via energizing the mesh with a low intensity, resonant acoustic field. The resulting acoustic field induces the interaction of cells with elements of the mesh or with each other and effectively prevents the entrainment of cells in the effluent stream. Experiments involving aqueous suspensions of polystyrene particles were used to provide benchmark data on the performance of the acoustic retention cell. Experiments using mouse hybridoma cells showed that retention densities of over 1.5 × …

Go to article

Laboratory Automation Curriculum At Keck Graduate Institute, James D. Sterling Jan 2004

Laboratory Automation Curriculum At Keck Graduate Institute, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

A novel curriculum in laboratory automation and high-throughput technologies has been developed at the Keck Graduate Institute (KGI) over the past five years as part of the professional master's degree program in applied life sciences. The goal of this curriculum has been four-fold: (1) motivate study by describing the need for automation through several example problems in combinatorial biological discovery, (2) provide elements of fundamental engineering science that are required for the development of the technologies and tools that enable automation, (3) provide opportunities for the students to see and use state-of-the-art instruments, learn about existing industry standards, and to …

Go to article

Laboratory Automation Education, James D. Sterling Jan 2004

Laboratory Automation Education, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

Go to article

Centrifugal Extraction Of Avocado Oil From The Pulp, J. W. Ntalikwa Dec 2003

Centrifugal Extraction Of Avocado Oil From The Pulp, J. W. Ntalikwa

Tanzania Journal of Engineering and Technology (TJET)

Absract

Go to article

Kinetics Of Wet Air Oxidation Of Phenol Over A Novel Catalyst, Jing Guo, Muthanna H. Al-Dahhan Oct 2003

Kinetics Of Wet Air Oxidation Of Phenol Over A Novel Catalyst, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Wet Air Oxidation Kinetics of an Aqueous Solution of Phenol Was Studied over Extrudates of an Al-Fe Pillared Clay Catalyst in the Temperature Range of 90-150°C and Air Pressure Range of 0.8-2.5 MPa. the Variables Studied Included Reaction Temperature, Air Pressure, Solution PH, Initial Phenol Concentration, and Catalyst Loading. the Obtained Findings Are Compared with Those Obtained using Hydrogen Peroxide Oxidation. a Group of Kinetic Models Considering Both the Power-Law and Langmuir-Hinshelwood Approaches Was Evaluated to Describe the Catalytic Kinetics of the Phenol Disappearance. the Nonlinear Dependence of the Phenol Conversion Rate on the Catalyst Concentration Was Taken into …

Go to article

Preliminary Work On The Antibacterial Effect Of Strontium In Glass Ionomer Cements, A. Guida, Mark R. Towler, J. G. Wall, R. G. Hill, S. Eramo Oct 2003

Preliminary Work On The Antibacterial Effect Of Strontium In Glass Ionomer Cements, A. Guida, Mark R. Towler, J. G. Wall, R. G. Hill, S. Eramo

Chemical and Biochemical Engineering Faculty Research & Creative Works

The antibacterial effect of strontium in glass ionomer cements (GIC) was discussed. The glass transition temperatures were found to decrease with the increasing fluorine content consistent with the fluorine replacing bridging oxygens. However no significant correlation was found between the fluoride release and the antibacterial activity.

Go to article

Computation Of Effectiveness Factors For Partially Wetted Catalyst Pellets Using The Method Of Fundamental Solution, E. Palmisano, P. A. Ramachandran, K. Balakrishnan, M. (Muthanna) H. Al-Dahhan Oct 2003

Computation Of Effectiveness Factors For Partially Wetted Catalyst Pellets Using The Method Of Fundamental Solution, E. Palmisano, P. A. Ramachandran, K. Balakrishnan, M. (Muthanna) H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Trickle Bed Reactors Are Widely Used in Many Process Industries. the Catalyst Particles Are Often Incompletely Wetted Especially in the Trickling Flow Regime and Hence to Design These Reactors, the Effectiveness Factor of Partially Wetted Catalyst Needs to Be Calculated Accurately. Numerical Solutions by Traditional Methods Are Time Consuming and Not Very Accurate, Especially for Some Commonly Used Complex Catalyst Shapes Such as Trilobes, Quadrilobes Etc. the Paper Presents a Novel Numerical Solution for These Problems based on the Method of Fundamental Solutions. the Advantage of the Method is that It Involves Only Boundary Collocation and Can Be Applied to …

Go to article

Resolution Of Multiple Ssdna Structures In Free Solution Electrophoresis, Eve F. Fabrizio, Ali Nadim, James D. Sterling Oct 2003

Resolution Of Multiple Ssdna Structures In Free Solution Electrophoresis, Eve F. Fabrizio, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

By using high concentrations of buffer, electroosmotic flow within uncoated channels of a microfluidic chip was minimized, allowing the free solution electrophoretic separation of DNA. More importantly, because of the ability to efficiently dissipate heat within these channels, field strengths as high as 600 V/cm could be applied with minimal Joule heating (< 2 °C). As a result of the higher field strengths, separations within an 8-cm-long channel were achieved within a few minutes. However, when the electrophoretic separation of single-stranded DNA (ssDNA) less than 22 bases in length was performed, containing the fluorophore Texas Red as an end label, more than the expected single peak was observed at this high electric field. On the other hand, the free solution electrophoresis of a double-stranded DNA (dsDNA) consisting of a random sequence did exhibit the expected single peak. The appearance of these multiple peaks for ssDNA is shown to be dependent upon the base content and sequence of the ssDNA as well as on the chemical structure of the fluorophore used to tag the DNA for detection. Specifically, the peaks can be attributed to different secondary structures that result either from hydrophobic interactions between the DNA bases and an uncharged fluorescent dye or from G-quadruplexes within guanine-rich strands.

Go to article

Expressions For Evaluating The Possibility Of Slip At The Liquid-Solid Interface In Open Tube Capillary Electrochromatography, B. A. Grimes, Athanasios I. Liapis Jul 2003

Expressions For Evaluating The Possibility Of Slip At The Liquid-Solid Interface In Open Tube Capillary Electrochromatography, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, expressions are constructed and solved that describe the velocity field of electroosmotic flow (EOF) in open tube capillary electrochromatography (CEC) systems when the possibility of having unequal tangential velocities at the liquid-solid interface is considered and a slip condition is employed as a boundary condition for the velocity of the EOF at the capillary wall. the coupled equations of hydrodynamics (momentum balance equation) and electrostatics (Poisson equation) are solved numerically in order to obtain the distribution of the velocity field as well as the value of the volumetric flow rate in the open tube. Also, expressions for …

Go to article

Characterization And Optimization Of A Chromatographic Process Based On Ethylenediamine-N,N,N′,N′-Tetra(Methylphosphonic) Acid-Modified Zirconia Particles, Sabyasachi Sarkar, Peter W. Carr, Clayton V. Mcneff, Anuradha Subramanian Jun 2003

Characterization And Optimization Of A Chromatographic Process Based On Ethylenediamine-N,N,N′,N′-Tetra(Methylphosphonic) Acid-Modified Zirconia Particles, Sabyasachi Sarkar, Peter W. Carr, Clayton V. Mcneff, Anuradha Subramanian

Papers in Biotechnology

The primary objective of work was to characterize, optimize and model a chromatographic process based on ethylenediamine-N,N,N′,N′-tetra(methylphosphonic) acid (EDTPA)-modified zirconia particles. Zirconia particles were produced by spray-drying colloidal zirconia. Zirconia spheres produced were further classified, calcined and modified with EDTPA to yield a solid-phase support for use in bio-chromatography (r_PEZ). Specifically, the ability of r_PEZ to selectively bind and enrich IgG, IgA, and IgM from biological fluids was evaluated and demonstrated. To better understand the force of interaction between the IgG and the r_PEZ, the equilibrium disassociation constant (Kd) was determined by static binding isotherms, as a function of temperature …

Go to article

First Prev Next Last