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Articles 1171 - 1200 of 1431

Full-Text Articles in Chemical Engineering

Catalytic Wet Oxidation Of Phenol By Hydrogen Peroxide Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan Jun 2003

Catalytic Wet Oxidation Of Phenol By Hydrogen Peroxide Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Extrudates of Al-Fe Pillared Clay Catalyst Suitable for Packed-Bed Operations Are Evaluated for Wastewater Treatment Via a Wet Oxidation Process Employing Hydrogen Peroxide as the Oxidant. the Reaction Was Carried Out in a Semibatch Basket Reactor under Rather Mild Conditions. Operational Parameters Were Studied under the Following Conditions: Temperature from 25 to 90 °C, Atmospheric Pressure, Initial Phenol Concentration from 100 to 2000 Ppm of the Liquid Phase, Catalyst Loading from 0 to 10 G/L, and Input H2O2 Concentration from 0.15 to 0.6 Mol/L. under These Conditions, the Al-Fe Pillared Clay Catalyst Achieves a Total Elimination of Phenol and Significant …

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Shape-Controlled Synthesis Of Iron Oxide Nanoparticles, Yangchuan Xing, T. P. Kole, J. L. Katz Jun 2003

Shape-Controlled Synthesis Of Iron Oxide Nanoparticles, Yangchuan Xing, T. P. Kole, J. L. Katz

Chemical and Biochemical Engineering Faculty Research & Creative Works

A study on shape-controlled synthesis of iron oxide nanoparticles was presented. a specially designed counterflow diffusion flame (CDF) reactor was used to synthesize the iron oxide nanoparticles. It was observed that the properties of surface atoms on the nanoparticles are associated with the chemical environments, leading to the preferential growth of a particular crystallographic surface.

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Modeling Of The Fischer-Tropsch Synthesis In Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Dudukovic Apr 2003

Modeling Of The Fischer-Tropsch Synthesis In Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Multicomponent One-Dimensional Dynamic Mathematical Model for the Reacting Slurry Systems with a Change in Gas Flow Rate Due to the Chemical Reaction is Developed. a Change in Gas Flow Rate Caused by the Chemical Reaction is Modeled using the overall Gas Mass Balance. Thus, All Relevant Chemical Species Are Included in the Model. Linear First-Order Reaction Kinetics is Considered. the Gas Phase is Modeled using the Two-Bubble Class Hydrodynamic Model. the Interaction between Small and Large Bubbles is Included as the Cross-Flow. Suspension of Liquid and Solids is Assumed to Form a Pseudo Slurry Phase. Back-Mixing in All of …

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Use Of Combinatorial Genetic Libraries To Humanize N-Linked Glycosylation In The Yeast Pichia Pastoris, Byung-Kwon Choi, Piotr Bobrowicz, Robert C. Davidson, Stephen R. Hamilton, David Kung, Huijuan Li, Robert Miele, Juergen Nett, Stefan Wildt, Tillman Gerngross Apr 2003

Use Of Combinatorial Genetic Libraries To Humanize N-Linked Glycosylation In The Yeast Pichia Pastoris, Byung-Kwon Choi, Piotr Bobrowicz, Robert C. Davidson, Stephen R. Hamilton, David Kung, Huijuan Li, Robert Miele, Juergen Nett, Stefan Wildt, Tillman Gerngross

Dartmouth Scholarship

The secretory pathway of Pichia pastoris was genetically re-engineered to perform sequential glycosylation reactions that mimic early processing of N-glycans in humans and other higher mammals. After eliminating nonhuman glycosylation by deleting the initiating alpha-1,6-mannosyltransferase gene from P. pastoris, several combinatorial genetic libraries were constructed to localize active alpha-1,2-mannosidase and human beta-1,2-N-acetylglucosaminyltransferase I (GnTI) in the secretory pathway. First, >32 N-terminal leader sequences of fungal type II membrane proteins were cloned to generate a leader library. Two additional libraries encoding catalytic domains of alpha-1,2-mannosidases and GnTI from mammals, insects, amphibians, worms, and fungi were cloned to generate catalytic domain libraries. …

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Investigation Into The Ultrasound Setting Of Glass Ionomer Cements. Part I. Postulated Modalities, Mark R. Towler, C. M. Crowley, R. G. Hill Apr 2003

Investigation Into The Ultrasound Setting Of Glass Ionomer Cements. Part I. Postulated Modalities, Mark R. Towler, C. M. Crowley, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fuji IX glass is a low phosphate, low soda containing glass which has strontia incorporated as a radio-pacifier. This glass material was analyzed during exposure to different durations of ultrasound in an attempt to determine how the glass phase reacts. Cross sections of Fuji IX cement, set both conventionally and by ultrasound, were subsequently compared by microscopy. The resultant data were analyzed in detail.

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Transgenic Non-Human Mammals Expressing Human Coagulation Factor Viii And Von Willebrand Factor, Henryk Lubon, William N. Drohan, William H. Velander Feb 2003

Transgenic Non-Human Mammals Expressing Human Coagulation Factor Viii And Von Willebrand Factor, Henryk Lubon, William N. Drohan, William H. Velander

Papers in Biotechnology

A non-human transgenic mammalian animal, as described above, contains an exogenous double stranded DNA sequence stably integrated into the genome of the animal, which comprises cis-acting regulatory units operably linked to a DNA sequence encoding human Factor VIII protein and a signal peptide, where the cis-acting regulatory units are active in mammary gland cells and the signal peptide is active in directing newly expressed Factor VIII into the milk of the animal. The promoter may be a milk protein promoter such as for whey acidic protein, casein, lactalbumin, or beta-lactoglobulin promoter. The transgenic mammals are preferably farm animals, for example, …

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Pichia Pastoris Fermentation With Mixed-Feeds Of Glycerol And Methanol: Growth Kinetics And Production Improvement, Wenhui Zhang, Karen J. Hywood Potter, Bradley A. Plantz, Vicki L. Schlegel, Leonard A. Smith, Michael M. Meagher Jan 2003

Pichia Pastoris Fermentation With Mixed-Feeds Of Glycerol And Methanol: Growth Kinetics And Production Improvement, Wenhui Zhang, Karen J. Hywood Potter, Bradley A. Plantz, Vicki L. Schlegel, Leonard A. Smith, Michael M. Meagher

Papers in Biochemical Engineering

Fed-batch fermentation of a methanol utilization plus (Mut+) Pichia pastoris strain typically has a growth phase followed by a production phase (induction phase). In the growth phase glycerol is usually used as carbon for cell growth while in the production phase methanol serves as both inducer and carbon source for recombinant protein expression. Some researchers employed a mixed glycerol-methanol feeding strategy during the induction phase to improve production, but growth kinetics on glycerol and methanol and the interaction between them were not reported. The objective of this paper is to optimize the mixed feeding strategy based on growth kinetic studies …

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Sequence Dependent Mobility Of Short Oligonucleotides In Free-Solution Electrophoresis, James D. Sterling, Eve F. Fabrizio, Ali Nadim Jan 2003

Sequence Dependent Mobility Of Short Oligonucleotides In Free-Solution Electrophoresis, James D. Sterling, Eve F. Fabrizio, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

No abstract provided.

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Analysis Of Photobioreactors For Culturing High-Value Microalgae And Cyanobacteria Via An Advanced Diagnostic Technique: Carpt, Hu Ping Luo, Abdenour Kemoun, Muthanna H. Al-Dahhan, J. M.Fernández Sevilla, J. L.García Sánchez, F. García Camacho, E. Molina Grima Jan 2003

Analysis Of Photobioreactors For Culturing High-Value Microalgae And Cyanobacteria Via An Advanced Diagnostic Technique: Carpt, Hu Ping Luo, Abdenour Kemoun, Muthanna H. Al-Dahhan, J. M.Fernández Sevilla, J. L.García Sánchez, F. García Camacho, E. Molina Grima

Chemical and Biochemical Engineering Faculty Research & Creative Works

Photosynthetic Algal Cultures Are a Potential Source of Many High-Value Products. in Photobioreactors (PBR), the Availability and the Intensity of the Light, Which Are Affected by the Cells' Movement, Are the Major Factors Controlling the Biomass Productivity. Hydrodynamics, Hence, Play a Significant Role in the Reactor's Performance, as They Determine Not Only the Flow Field, I.e. Liquid Flow and Mixing, Shear Stresses, Etc., But Also the Movements of the Cells. in This Work, Computer-Automated Radioactive Particle Tracking (CARPT) Technique Was Employed to Evaluate its Feasibility for Characterizing PBRs. Liquid Velocity Profiles, Cells' Movement, and the Temporal Irradiance Patterns Obtained by …

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Bubble Dynamics Measurements Using Four-Point Optical Probe, Junli Xue, Muthanna H. Al-Dahhan, M. P. Dudukovic, R. F. Mudde Jan 2003

Bubble Dynamics Measurements Using Four-Point Optical Probe, Junli Xue, Muthanna H. Al-Dahhan, M. P. Dudukovic, R. F. Mudde

Chemical and Biochemical Engineering Faculty Research & Creative Works

By Conducting an Analysis of the Measurement Errors It Was Found that Bubble Dynamics Obtained by Two-Point Probes Can Be Highly Inaccurate. a Four-Point Optical Probe with Appropriate Data Processing Algorithm Has Been Developed So that the Bubble Velocity Vector Can Be Obtained. This Probe Provides Directly the Value of Specific Gas-Liquid Interfacial Area. However, for Obtaining Accurate Values of Bubble Velocity and Size, the Four-Point Probe Must Be Calibrated by a CCD Camera at the Same Conditions. Calibration Columns Have Been Developed for This Purpose Where the Bubble Size and Velocity Can Be Varied to Calibrate the Measurements by …

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Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti Dec 2002

Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computer simulations in conjunction with neutron reflectivity is an excellent combination for the study of biological materials at solid-liquid interfaces: Both techniques have excellent resolution levels (Ångströms) and they are mature. A stronger interaction between physicists and biologists will allow the use of these two approaches in topics of biological-biomedical interest.

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Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis Dec 2002

Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Novel general expressions are constructed and presented that describe the behavior of the height equivalent of a theoretical plate (plate height), H, as a function of the linear velocity, Vx, along the axis, x, of the column and the kinetic parameters that characterize the mass transfer and adsorption mechanisms in chromatographic columns. Open tube capillaries as well as columns packed with either non-porous or porous particles are studied. The porous particles could have unimodal or bimodal pore-size distributions and intraparticle convective fluid flow and pore diffusion are considered. The expressions for the plate height, H, presented in this work could …

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The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis Dec 2002

The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, a mathematical model is constructed and solved to describe the propagation and dispersion of the mass wave of an analyte in a capillary electrochromatography (CEC) column packed with porous adsorbent particles and operated in the analytical mode. The evolution and dynamic behavior of the isoconcentration contours of the concentration of the analyte in the pores of the particles are presented in order to demonstrate the significant impact that the velocity of the intraparticle electroosmotic flow (EOF) encountered in CEC systems could have in reducing the overall intraparticle mass transfer resistance. It is shown that under both unretained …

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Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling Nov 2002

Method, Apparatus And Article For Microfluidic Control Via Electrowetting, For Chemical, Biochemical And Biological Assays And The Like, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

An active-matrix microfluidic platform employs thin film transistor active ("TFT") matrix liquid crystal display ~ technology to manipulate small samples of fluid for chemical, biochemical, or biological assays without moving parts, for example, using a two-dimensional matrix array of drive electrodes. The active-matrix microfluidic platform may employ existing active matrix 0 addressing schemes and/or commercial "off-the-shelf" animation software to program assay protocols. A feedback subsystem may > determine an actual location of a fluid in the microfluidic structure, and provides location information to for display, for example, on an active-matrix display, and/or to control movement of one or more fluid bodies …

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An Approach To Sequence Dna Without Tagging, Sanjun Niu, Ravi F. Saraf Sep 2002

An Approach To Sequence Dna Without Tagging, Sanjun Niu, Ravi F. Saraf

Papers in Biotechnology

Microarray technology is playing an increasingly important role in biology and medicine and its application to genomics for gene expression analysis has already reached the market with a variety of commercially available instruments. In these combinatorial analysis methods, known probe single-strand DNA (ssDNA) ‘primers’ are attached in clusters of typically 100 μm × 100 μm pixels. Each pixel of the array has a slightly different sequence. On exposure to ‘unknown’ target ssDNA, the pixels with the right complementary probe ssDNA sequence convert to double-stranded DNA (dsDNA) by a hybridization reaction. To transduct the conversion of the pixel to dsDNA, the …

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Microbial Cellulose Utilization: Fundamentals And Biotechnology, Lee R. Lynd, Paul J. Weimer, Willem H. Van Zyl, Isak S. Pretorius Sep 2002

Microbial Cellulose Utilization: Fundamentals And Biotechnology, Lee R. Lynd, Paul J. Weimer, Willem H. Van Zyl, Isak S. Pretorius

Dartmouth Scholarship

Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial …

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Fluoride Release From Model Glass Ionomer Cements, A. Guida, R. G. Hill, Mark R. Towler, S. Eramo Jul 2002

Fluoride Release From Model Glass Ionomer Cements, A. Guida, R. G. Hill, Mark R. Towler, S. Eramo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass ionomer cements (GICs) are an important class of biomedical material used extensively for color matched mercury free, dental restorations. GICs can release clinically beneficial amounts of fluoride and have acceptable handling properties which make them suitable as dental restoratives. The fluoride release of model GICs produced from specially synthesized fluoro-alumino-silicate glasses was studied. Nine glasses of varying fluoride content based on 4.5SiO2-3Al2O3-1.5P2O5-(5-Z)CaO-ZCaF2 were synthesized, and cement disks were prepared from them. The glass transition temperature reduced with increasing fluorine content of the glass. Fluoride ion release was measured …

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A Preliminary Study Of An Aluminum-Free Glass Polyalkenoate Cement, Mark R. Towler, C. M. Crowley, D. Murphy, A. M.C. O'Callaghan Jul 2002

A Preliminary Study Of An Aluminum-Free Glass Polyalkenoate Cement, Mark R. Towler, C. M. Crowley, D. Murphy, A. M.C. O'Callaghan

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

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Cfd Of Multiphase Flow In Packed-Bed Reactors: I. K-Fluid Modeling Issues, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Apr 2002

Cfd Of Multiphase Flow In Packed-Bed Reactors: I. K-Fluid Modeling Issues, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Eulerian K-Fluid CFD Model Was Used to Simulate the Macroscale Multiphase Flow in Packed Beds. the Geometric Complexity of the Bed Structure is Resolved by Statistically Describing the Porosity Distribution. the Complicated Multiphase Interactions Are Computed using the Ergun Type of Formula Developed based on Bench-Scale Hydrodynamic Experiments. the Work is Presented in Two Sequential Articles. Part I Discusses Implementation Issues of the K-Fluid CFD Model for Packed Beds. the Drag Exchange Coefficients Are Obtained from the Model of Holub Et Al. for the Particle-Fluid Interfaces Xks and from the Model of Attou Et Al. (1999) for the Gas …

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Cfd Of Multiphase Flow In Packed-Bed Reactors: Ii. Results And Applications, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Apr 2002

Cfd Of Multiphase Flow In Packed-Bed Reactors: Ii. Results And Applications, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Numerical Simulations of Multiphase Flow using the K-Fluid CFD Model Described in Part I of This Issue Are Presented for Packed Beds at Various Operating Conditions. Both Steady-State and Unsteady-State (E.g., Periodic Operation) Feed Conditions Were Studied Numerically. Predictions of the K-Fluid CFD Model Are Comparable with the Experimental Data in the Literature for Liquid Upflow in a Cylindrical Packed Bed. in Addition to the Mean Porosity and the Longitudinally Averaged Radial Porosity Profile, the Variance of the Porosity Distribution is Needed for Predicting the Probability Density Function of the Sectional Flow Velocity. in the Trickling Flow Regime, the K-Fluid …

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Ethylene Oxide And Propylene Oxide Random Copolymer/Sodium Chloride Aqueous Two-Phase Systems: Wetting And Adsorption On Dodecyl-Agarose And Polystyrene, Yingqing Huang, Daniel Forciniti Mar 2002

Ethylene Oxide And Propylene Oxide Random Copolymer/Sodium Chloride Aqueous Two-Phase Systems: Wetting And Adsorption On Dodecyl-Agarose And Polystyrene, Yingqing Huang, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Liquid/liquid partition chromatography is a mild yet powerful separation method for a variety of biological materials. This work demonstrates that it should be feasible to immobilize an ethylene oxide-propylene oxide (EO/PO) random copolymer solution and to use a solution of NaCl equilibrated against the polymer solution as the mobile-phase (poly (EO-PO) [P(EO-PO)] and NaCl form two aqueous phases known as aqueous two-phase systems). Three random copolymers with different molecular weights and EO/PO ratios were used. Dodecyl-agarose and polystyrene were tested as possible supports. The wetting energies of the aqueous two-phase systems on these two kinds of surfaces were calculated as …

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Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol Mar 2002

Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fly ashes exist as a mixture of major amorphous phases and minor crystalline phases. For commercial applications, such as in concretes and for the production of zeolites, it would be desirable to be able to predict the reactivity of fly ashes. The amorphous phase dominates degradation behaviour, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. Despite the large quantities of fly ash produced annually by coal-burning power plants, there have been very few studies investigating the microstructure and composition of …

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Thermodynamics And Bioenergetics, Yaşar Demirel, Stanley I. Sandler Mar 2002

Thermodynamics And Bioenergetics, Yaşar Demirel, Stanley I. Sandler

Papers in Thermal Mechanics

Bioenergetics is concerned with the energy conservation and conversion processes in a living cell, particularly in the inner membrane of the mitochondrion. This review summarizes the role of thermodynamics in understanding the coupling between the chemical reactions and the transport of substances in bioenergetics. Thermodynamics has the advantages of identifying possible pathways, providing a measure of the efficiency of energy conversion, and of the coupling between various processes without requiring a detailed knowledge of the underlying mechanisms. In the last five decades, various new approaches in thermodynamics, non-equilibrium thermodynamics and network thermodynamics have been developed to understand the transport and …

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Thermodynamics And Bioenergetics, Yaşar Demirel, Stanley I. Sandler Mar 2002

Thermodynamics And Bioenergetics, Yaşar Demirel, Stanley I. Sandler

Papers in Thermal Mechanics

Bioenergetics is concerned with the energy conservation and conversion processes in a living cell, particularly in the inner membrane of the mitochondrion. This review summarizes the role of thermodynamics in understanding the coupling between the chemical reactions and the transport of substances in bioenergetics. Thermodynamics has the advantages of identifying possible pathways, providing a measure of the efficiency of energy conversion, and of the coupling between various processes without requiring a detailed knowledge of the underlying mechanisms. In the last five decades, various new approaches in thermodynamics, non-equilibrium thermodynamics and network thermodynamics have been developed to understand the transport and …

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Expression Of Active Human Factor Ix In Mammary Tissue And Of Milk Non Human Transgenic Mammals , William H. Velander, William N. Drohan Feb 2002

Expression Of Active Human Factor Ix In Mammary Tissue And Of Milk Non Human Transgenic Mammals , William H. Velander, William N. Drohan

Papers in Biotechnology

Recombinant Factor IX characterized by a high percentage of active protein can be obtained in the milk of transgenic animals that incorporate chimeric DNA molecules according to the present invention. Transgenic animals of the present invention are produced by introducing into developing embryos DNA that encodes Factor IX, such that the foreign DNA is stably incorporated in the DNA of germ line cells of the mature animal. Particularly efficient expression was accomplished using a chimeric construct comprising a mammary gland specific promoter, Factor IX cDNA that lacked the complete or any portion of the 5'-untranslated and 3'-untranslated region, which is …

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Enzyme Profiles Of Pycnoporus Sanguineus Growing In Solid Substrate Fermentation On Selected Agro-Residues, Renuvathani Madavan Jan 2002

Enzyme Profiles Of Pycnoporus Sanguineus Growing In Solid Substrate Fermentation On Selected Agro-Residues, Renuvathani Madavan

Student Works (2000-2009)

A comparative study was done for solid substrate fermentation (SSF) of sago 'hampas', oil palm frond parenchyma tissue (OPFPI) and rubberwood sawdust with a white-rot fungus, Pycnoporus sanguineous for enzyme production. Xylanase, laccase and cellulase productivity was assayed during degradation. Excellent growth of Pycnoporus sanguineous was observed for all the substrates studied over a 21 day time-course fermentation. Laccase productivity was highest during degradation of sago 'hampas' and OPFPI ranging from 7.4-7.6 U/g substrate on 1111 day of fermentation compared to rubberwood sawdust with a maximum laccase of 5.7 U/g substrate on day 11 of SSF. Xylanase productivity recorded highest …

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Ultrafast Flow Quantification With Segmented K-Space Magnetic Resonance Phase Velocity Mapping, Haosen Zhang, Sandra S. Halliburton, James R. Moore, Orlando P. Simonetti, Paulo R. Schvartzman, Richard D. White, George P. Chatzimavroudis Jan 2002

Ultrafast Flow Quantification With Segmented K-Space Magnetic Resonance Phase Velocity Mapping, Haosen Zhang, Sandra S. Halliburton, James R. Moore, Orlando P. Simonetti, Paulo R. Schvartzman, Richard D. White, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Magnetic resonance (MR) phase-velocity mapping (PVM) is routinely being used clinically to measure blood flow velocity. Conventional nonsegmented PVM is accurate but relatively slow (3–5 min per measurement). Ultrafast k-space segmented PVM offers much shorter acquisitions (on the order of seconds instead of minutes). The aim of this study was to evaluate the accuracy of segmented PVM in quantifying flow from through-plane velocity measurements. Experiments were performed using four straight tubes (inner diameter of 5.6–26.2 mm), under a variety of steady (1.7–200 ml/s) and pulsatile (6–90 ml/cycle) flow conditions. Two different segmented PVM schemes were …

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Biological Reduction Of Perchlorate In Ion Exchange Regenerant Solutions Containing High Salinity And Ammonium Levels, Tina M. Gingras, Jacimaria R. Batista Jan 2002

Biological Reduction Of Perchlorate In Ion Exchange Regenerant Solutions Containing High Salinity And Ammonium Levels, Tina M. Gingras, Jacimaria R. Batista

Civil and Environmental Engineering and Construction Faculty Research

The most promising technologies to remove perchlorate from water are ion exchange and biological reduction. Although successful, ion exchange only separates perchlorate from water; it does not eliminate it from the environment. The waste streams from these systems contain the caustic or saline regenerant solutions used in the process as well as high levels of perchlorate. Biological reduction could be used to treat the regenerant waste solutions from the ion exchange process. A treatment scheme, combining ion exchange and biodegradation, is proposed to completely remove perchlorate from the environment. Perchlorate-laden resins generate brines containing salt concentrations up to 6% or …

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Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol Jan 2002

Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol

Chemical and Biochemical Engineering Faculty Research & Creative Works

The amorphous phase of fly ash dominates degradation behaviour because glass has a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. It would be advantageous to predict the presence and subsequent degradability of glass on the basis of the solid-state chemistry of the fly ash. To this end, and inorganic polymer model was applied to a selection of European fly ashes to determine the value known as cross-link density (CLD). A cross-link density value of less than two implies that the material is amorphous …

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Incorporation Of Cerium And Neodymium In A Uranyl Hydroxide Solid, Chang-Soo Kim, David J. Wronkiewicz, R. J. Finch, E. C. Buck Jan 2002

Incorporation Of Cerium And Neodymium In A Uranyl Hydroxide Solid, Chang-Soo Kim, David J. Wronkiewicz, R. J. Finch, E. C. Buck

Electrical and Computer Engineering Faculty Research & Creative Works

The migration behavior of radionuclides in a nuclear-waste repository will be influenced, in part, by their equilibrium solubilities in the presence of radionuclide-bearing solids and/or adsorption affinities as trace components onto the surfaces of solid host phases. Uranium phases that precipitate on the surface of altered spent nuclear fuel may thus influence the mobility of radionuclides released in the near-field environment, since by proximity, these will be the first phases that the radionuclides encounter following their release from the spent fuel matrix. We have evaluated the potential for incorporating radionuclides into crystalline compounds by precipitating uranyl phases from aqueous solutions …

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