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2000

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Articles 91 - 110 of 110

Full-Text Articles in Chemical Engineering

Reconstitution And Characterization Of Membrane Proteins, Sarah Mia Pates Jan 2000

Reconstitution And Characterization Of Membrane Proteins, Sarah Mia Pates

Masters Theses

“A membrane protein, cytochrome c reductase, was crystallized and examined using transmission electron microscopy. Two-dimensional crystals were prepared by two methods. In Method 1, the protein was solubilized in 50 mM Tris-Acetate (pH 6.0)/0.5 mM EDTA70.05% (w/v) Triton X-100 and reconstituted into a mixture of phosphatidylcholine and phosphatidylserine (4:1), dissolved in the same buffer. The Triton X-100 was removed from the mixture by dialysis in the presence of Bio-beads (SM-2) at approximately 25-30 °C. Method 2 was the same as Method 1, except that the vesicles were fractionated before reconstitution, and the pH and temperature for crystallization were 7.0 and …

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Effects Of Cosolvents And Ph On Protein Adsorption On Polystyrene Latex: A Dynamic Light Scattering Study, Da Song, Daniel Forciniti Jan 2000

Effects Of Cosolvents And Ph On Protein Adsorption On Polystyrene Latex: A Dynamic Light Scattering Study, Da Song, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Dynamic light scattering was used to study the adsorption of two proteins with different surface properties (IgG and HSA) on negatively charged polystyrene latex. The proteins were adsorbed from water and from water/methanol and water/glycerol mixtures at various pH. Some striking differences between the adsorption behaviors of the proteins were observed. Whereas the thickness of the adsorbed layer of HSA was extremely sensitive to pH and solvent composition, that of IgG was not. IgG mainly showed an end-on orientation on polystyrene whereas several different surface orientations are suggested for HSA under different conditions. The addition of methanol inhibited the adsorption …

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Drawbacks Of The Dissolution Method For Measurement Of The Liquid-Solid Mass-Transfer Coefficients In Two-Phase Flow Packed-Bed Reactors Operated At Low And High Pressures, Muthanna H. Al-Dahhan, Wes Highfill, Boon Tee Ong Jan 2000

Drawbacks Of The Dissolution Method For Measurement Of The Liquid-Solid Mass-Transfer Coefficients In Two-Phase Flow Packed-Bed Reactors Operated At Low And High Pressures, Muthanna H. Al-Dahhan, Wes Highfill, Boon Tee Ong

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Dissolution Method Was Used Predominantly at Atmospheric Conditions to Measure the Liquid-Solid Mass-Transfer Coefficient in Two-Phase Flow Packed-Bed Reactors. in an Attempt to Investigate the Effect of Reactor Pressure and Gas Flow Rate on the Liquid-Solid Mass-Transfer Coefficient in a Trickle-Bed Reactor using the Dissolution Method, Difficulties Were Encountered in Implementing This Method at Low- to High-Pressure Operation. Noticeable Losses in the Dissolved Material Were Observed as a Result of Flashing/stripping from the Liquid Phase to the Atmosphere and the Effluent Gas Stream. This Leads to Misinterpretation of the Effect of Reactor Pressure and to Improper Conclusions. in This …

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Discriminating Trickle-Flow Hydrodynamic Models: Some Recommendations, F. Larachi, I. Iliuta, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Jan 2000

Discriminating Trickle-Flow Hydrodynamic Models: Some Recommendations, F. Larachi, I. Iliuta, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Forecasting Ability of Five One-Dimensional (1-D) Two-Fluid Phenomenological Models for Liquid Holdup and Two-Phase Pressure Drop in Trickle-Flow Reactors Was Evaluated using the Most Comprehensive Trickle-Flow Regime Database. All of These Models, Namely, the Permeability Model, the Slit Model, the Extended Slit Model, the 1-D CFD Model, and the Double-Slit Model Can Be Used to Predict Liquid Holdup. among Them, the Permeability and the Slit Models, Because of a Much Simpler Structure, Are Recommended. the Extended Slit Model based on Iliuta Et Al. (Ind. Eng. Chem. Res. 1998, 37, 4542) Shear and Slip Constitutive Relationships Can Be Employed for …

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Double-Slit Model For Partially Wetted Trickle Flow Hydrodynamics, I. Iliuta, F. Larachi, M. (Muthanna) H. Al-Dahhan Jan 2000

Double-Slit Model For Partially Wetted Trickle Flow Hydrodynamics, I. Iliuta, F. Larachi, M. (Muthanna) H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Double-Slit Model Developed Can Predict the Frictional Two-Phase Pressure Drop, External Liquid Holdup, Pellet-Scale External Wetting Efficiency, and Gas - Liquid Interfacial Area in Cocurrent Downflow Trickle-Bed Reactors Operated under Partially Wetted Conditions in the Trickle Flow Regime. the Model, an Extension of the Holub Et Al. (1992, 1993) Mechanistic Pore-Scale Phenomenological Approach, Was Designed to Mimic the Actual Bed Void by Two Inclined and Interconnected Slits: Wet and Dry Slit. the External Wetting Efficiency is Linked to Both the Pressure Drop and External Liquid Holdup. the Model Also Predicts Gas - Liquid Interfacial Areas in Partially Wetted Conditions. …

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The Influence Of Poly(Acrylic Acid) Molar Mass On The Properties Of Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Sinead Kenny, Robert G. Hill, Mark R. Towler Jan 2000

The Influence Of Poly(Acrylic Acid) Molar Mass On The Properties Of Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Sinead Kenny, Robert G. Hill, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The influence of poly (acrylic acid) molar mass was investigated on cements formed from zinc oxide-apatite mixtures at three aging times: one, seven and 28 days. Cements based on both hydroxyapatite and fluorapatite were investigated. The compressive strength, un-notched fracture strength and fracture toughness increased markedly with poly (acrylic acid) molar mass. The fracture toughness and un-notched fracture strength increased with aging time for the two highest molar mass cements but decreased with time for the two lowest molar mass cements. The greater chain entanglement density present in the higher molar mass cements is thought to contribute significantly to the …

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Studies On The Capacitance Of Nickel Oxide Films: Effect Of Heating Temperature And Electrolyte Concentration, Venkat Srinivasan, John W. Weidner Jan 2000

Studies On The Capacitance Of Nickel Oxide Films: Effect Of Heating Temperature And Electrolyte Concentration, Venkat Srinivasan, John W. Weidner

Faculty Publications

Nickel oxide films were prepared by electrochemically precipitating the hydroxide and heating it in air to form the oxide. The resulting oxide films behave as a capacitor. The capacitance of the oxide depends on the heating temperature, showing a maximum at 300°C. The mechanism of charge storage was studied by measuring the capacitance and surface area as a function of heating temperature, and the capacitance in different electrolytes and potential windows. The charge-storage mechanism is believed to be a surface redox reaction involving adsorbed hydroxyl ions.

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Production And Purification Of The Heavy Chain Fragment C Of Botulinum Neurotoxin, Serotype A, Expressed In The Methylotrophic Yeast Pichia Pastoris, Karen J. Potter, Wenhui Zhang, Leonard A. Smith, Michael M. Meagher Jan 2000

Production And Purification Of The Heavy Chain Fragment C Of Botulinum Neurotoxin, Serotype A, Expressed In The Methylotrophic Yeast Pichia Pastoris, Karen J. Potter, Wenhui Zhang, Leonard A. Smith, Michael M. Meagher

Michael Meagher Publications

A recombinant Hc fragment of botulinum neurotoxin, serotype A (rBoNTA(Hc)), has been successfully expressed in a Mutt strain of the methylotrophic yeast Pichia pastoris for use as an antigen in a proposed human vaccine. Fermentation employed glycerol batch, glycerol-fed batch, and methanol-fed batch phases to achieve high cell density. Induction times were short to maximize rBoNTA(Hc) production while minimizing proteolytic degradation. Concentration of rBoNTA(Hc) in yeast cell lysates was generally 1-2% of the total protein based on ELISA analysis. The Hc fragment was purified from cell lysates using a multistep ion-exchange (IEC) chromatographic process, including …

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Development Of A New Electrodeposition Process For Plating Of Zn-Ni-X (X = Cd, P) Alloys: I. Corrosion Characteristics Of Zn-Ni-Cd Ternary Alloys, Anand Durairajan, Bala S. Haran, Ralph E. White, Branko N. Popov Jan 2000

Development Of A New Electrodeposition Process For Plating Of Zn-Ni-X (X = Cd, P) Alloys: I. Corrosion Characteristics Of Zn-Ni-Cd Ternary Alloys, Anand Durairajan, Bala S. Haran, Ralph E. White, Branko N. Popov

Faculty Publications

A new Zn-Ni-Cd plating process was developed which offers a unique way of controlling and optimizing the Ni and Cd contents in the final deposit. Zinc-nickel-cadmium alloy was deposited from a 0.5 M NiSO4 + 0.2 M ZnSO4 bath in the presence of 0.015 M CdSO4 and 1 g/L nonyl phenyl polyethylene oxide. Using this process a Zn-Ni-Cd ternary alloy, with a higher nickel content as compared to that obtained from conventional Zn-Ni baths, was synthesized. The Zn-Ni-Cd alloy coatings deposited from an electrolyte containing 0.015 M (0.3%) CdSO4 has a Zn to Ni ratio of …

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Ni-Composite Microencapsulated Graphite As The Negative Electrode In Lithium-Ion Batteries Ii: Electrochemical Impedance And Self-Discharge Studies, P. Yu, James A. Ritter, Ralph E. White, Branko N. Popov Jan 2000

Ni-Composite Microencapsulated Graphite As The Negative Electrode In Lithium-Ion Batteries Ii: Electrochemical Impedance And Self-Discharge Studies, P. Yu, James A. Ritter, Ralph E. White, Branko N. Popov

Faculty Publications

Electrochemical impedance and self-discharge studies were carried out to investigate lithium intercalation into bare and Ni-coated KS10 graphite. Values of the charge-transfer resistances, exchange current densities, surface film resistances, and lithium-ion diffusion coefficients as functions of the state of charge (SOC) all favored the 10 wt % Ni composite KS10 graphite over bare KS10 graphite when these materials were used as the negative electrode in a Li-ion cell with mixed organic electrolyte. The charge-transfer resistances were always lower and gave rise to between 26 and 27% larger exchange current densities, which increased from 137 to 614 mA/g as the SOC …

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A Semianalytical Method For Predicting Primary And Secondary Current Density Distributions: Linear And Nonlinear Boundary Conditions, Dhanwa Thirumalai, Ralph E. White Jan 2000

A Semianalytical Method For Predicting Primary And Secondary Current Density Distributions: Linear And Nonlinear Boundary Conditions, Dhanwa Thirumalai, Ralph E. White

Faculty Publications

No abstract provided.

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Development Of A New Electrodeposition Process For Plating Of Zn‐Ni‐X (X = Cd, P) Alloys: I. Corrosion Characteristics Of Zn‐Ni‐Cd Ternary Alloys, Anand Durairajan, Bala S. Haran, Ralph E. White, Branko Popov Jan 2000

Development Of A New Electrodeposition Process For Plating Of Zn‐Ni‐X (X = Cd, P) Alloys: I. Corrosion Characteristics Of Zn‐Ni‐Cd Ternary Alloys, Anand Durairajan, Bala S. Haran, Ralph E. White, Branko Popov

Faculty Publications

No abstract provided.

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Computational Fluid Dynamics Modeling Of A Lithium/Thionyl Chloride Battery With Electrolyte Flow, W. B. Gu, C. Y. Wang, John W. Weidner, Rudolph G. Jungst, Ganesan Nagasubramanian Jan 2000

Computational Fluid Dynamics Modeling Of A Lithium/Thionyl Chloride Battery With Electrolyte Flow, W. B. Gu, C. Y. Wang, John W. Weidner, Rudolph G. Jungst, Ganesan Nagasubramanian

Faculty Publications

A two-dimensional model is developed to simulate discharge of a lithium/thionyl chloride primary battery. As in earlier one-dimensional models, the model accounts for transport of species and charge, and electrode porosity variations and electrolyte flow induced by the volume reduction caused by electrochemical reactions. Numerical simulations are performed using a finite volume method of computational fluid dynamics. The predicted discharge curves for various temperatures show good agreement with published experimental data, and are essentially identical to results published for one-dimensional models. The detailed two-dimensional flow simulations show that the electrolyte is replenished from the cell head space predominantly through the …

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Development Of A New Electrodeposition Process For Plating Of Zn-Ni-X (X = Cd, P) Alloys: Permeation Characteristics Of Zn-Ni-Cd Ternary Alloys, A. Durairajan, B. S. Haran, Ralph E. White, Branko N. Popov Jan 2000

Development Of A New Electrodeposition Process For Plating Of Zn-Ni-X (X = Cd, P) Alloys: Permeation Characteristics Of Zn-Ni-Cd Ternary Alloys, A. Durairajan, B. S. Haran, Ralph E. White, Branko N. Popov

Faculty Publications

It is shown that an electrodeposited Zn-Ni-Cd alloy coating produced from sulfate electrolyte inhibits the discharge of hydrogen on carbon steel. The newly developed ternary alloys have approximately ten times higher corrosion resistance when compared to a Zn-Ni alloy. Hydrogen permeation characteristics of Zn-Ni-Cd alloy coatings were studied and compared with those of a bare and a Zn-Ni alloy coated steel. The transfer coefficient, a, exchange current density, io, thickness dependent adsorption-absorption rate constant, k0, recombination rate constant, k3, surface hydrogen coverage, θH, were obtained by applying a mathematical model to experimental results. Alloys obtained from baths containing higher concentration …

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Modeling Lithium Intercalation Of A Single Spinel Particle Under Potentiodynamic Control, Dong Zhang, Branko N. Popov, Ralph E. White Jan 2000

Modeling Lithium Intercalation Of A Single Spinel Particle Under Potentiodynamic Control, Dong Zhang, Branko N. Popov, Ralph E. White

Faculty Publications

A mathematical model is presented for the lithium intercalation of a single spinel particle as a microelectrode under the stimulus of a cyclic linear potential sweep. The model includes both lithium diffusion within the particle and kinetics at the particle/electrolyte interface. The model is used to predict that peak current densities depend linearly on the scan rate to a certain power with a constant term, which is different from the predicted peak current density for a conventional redox system.

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Shrinking Core Model For The Discharge Of A Metal Hydride Electrode, Venkat R. Subramanian, Harry J. Ploehn, Ralph E. White Jan 2000

Shrinking Core Model For The Discharge Of A Metal Hydride Electrode, Venkat R. Subramanian, Harry J. Ploehn, Ralph E. White

Faculty Publications

A shrinking core model is presented for the galvanostatic discharge of a metal hydride particle. A quantitative criterion for when the shrinking core can be completely neglected or approximated by a pseudosteady-state solution is presented. The effect of shrinking of the core on the discharge behavior of a metal hydride particle is also studied.

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Production Of 2,3-Butanediol From Molasses, Isita Sengupta Jan 2000

Production Of 2,3-Butanediol From Molasses, Isita Sengupta

Student Works (2000-2009)

2,3-Butanediol is an important chemical, which is used in the manufacture of products such as synthetic rubber, printing inks, perfumes, fumigants, moistening and softening agents, explosives and plasticizers. It has been known as a bacterial fermentation product since early part of the 20th century. Klebsiella oxytoca Is an organism, which can convert a variety of sugars to 2,3-butanediol. Available literature shows that principal monosaccharides of cellulosic substances as well as major hemicellulosic compounds have been used as carbon source. However, there is very little information on the application of waste material as carbon source for fermentation of butanediol. In this …

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Production Of Polyhydroaxyalkanoate (Pha) From Palm Oil By Pseudomonas Oleovorans And Indigenous Bacterial Isolate, Pseudomonas Sp., Zazali Alias Jan 2000

Production Of Polyhydroaxyalkanoate (Pha) From Palm Oil By Pseudomonas Oleovorans And Indigenous Bacterial Isolate, Pseudomonas Sp., Zazali Alias

Student Works (2000-2009)

In this study, the yield of biomass and polyhydroxyalkanoate  (PHA) of Pseudomonas oleovorans grown in batch and fed-batch cultivations were compared. When oleic acid (QA) (0.5% w/v) was used as carbon source, a significant increase in biomass.and PHA content were observed through fedbatch cultivation. The biomass and PHA content obtained from batch cultivation were 1.45±0.19 g/I and 2.50±0.77 % cell dry weight (CDW) respectively, while in the fed-batch cultivation, the biomass and PHA content increased significantly to 3.35±0.78 g/I and 32.72±0.30 %CDW respectively.  When saponified palm olein (SPO) (0.5% w/v) was used as a carbon source, the batch cultivation yielded …

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Urea Hydrolysis Using Immobilized Urease, Anita Arullan Jan 2000

Urea Hydrolysis Using Immobilized Urease, Anita Arullan

Student Works (2000-2009)

An inexpensive carrier matrix. vermiculite was used for immobilizing urease. A cost effective and simple method of coupling was developed using vermiculite. Immobilization of urease on Amberlite MB-land Nylon-6 tube were also studied. Activities of free and immobilized urease were studied and compared: Among all methods used for immobilization of urease. the method of coupling the enzyme to vermiculite gave the highest retained activity of 82% (Method I) and 89% (Method 2) at pH 6.0 and 5.5 respectively. Urease immobilized by Method I retained 69% and 30% of its original activity and Method 2 (using glutaraldehyde as coupling agent) retained …

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Clinical Waste Management In The Northern States Of Peninsular Malaysia, Sabah And Sarawak, Abdul Hai Akbar Ali Jan 2000

Clinical Waste Management In The Northern States Of Peninsular Malaysia, Sabah And Sarawak, Abdul Hai Akbar Ali

Student Works (2000-2009)

Clinical waste management and disposal methods are quite unique due to their infectious and harmful nature. Unlike municipal waste, clinical waste is pathogenic which jeopardizes the biotic community including human beings, if not quelled of its pathogenic effect.. However, shortcomings or drawbacks are still possible in areas of source separation. inappropriate containment and labeling. Improper incineration may also lead to incomplete combustion ultimately leading to air pollution. Though existing system of clinical waste disposal and management in Malaysia seem adequate, still efficient and cost effective mechanisms are needed. The focus of this research is to survey and study the administrative …

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