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2006

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Articles 1 - 30 of 30

Full-Text Articles in Biochemical and Biomolecular Engineering

Deposition Of Metallic Nanoparticles On Carbon Nanotubes Via A Fast Evaporation Process, Guoqiang Ren, Yangchuan Xing Nov 2006

Deposition Of Metallic Nanoparticles On Carbon Nanotubes Via A Fast Evaporation Process, Guoqiang Ren, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new technique was developed for the deposition of colloidal metal nanoparticles on carbon nanotubes. It involves fast evaporation of a suspension containing sonochemically functionalized carbon nanotubes and colloidal nanoparticles. It was demonstrated that metallic nanoparticles with different sizes and concentrations can be deposited on the carbon nanotubes with only a few agglomerates. the technique does not seem to be limited by what the nanoparticles are, and therefore would be applicable to the deposition of other nanoparticles on carbon nanotubes. PtPd and CoPt3 alloy nanoparticles were used to demonstrate the deposition process. It was found that the surfactants used to …

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Procedure To Quantify Biofilm Activity In Carriers Used In Wastewater Treatment Systems, James Bolton, Archana Tummala, Chirag Kapadia, Manoj Dandamudi, Joanne M. Belovich Nov 2006

Procedure To Quantify Biofilm Activity In Carriers Used In Wastewater Treatment Systems, James Bolton, Archana Tummala, Chirag Kapadia, Manoj Dandamudi, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A procedure is presented for evaluating and comparing the biological activity of biofilms attached to various biofilm carriers by measurement of the glucose consumption rate. This technique allows for the economical design and selection of small particulate biofilm carriers that will maximize substrate removal when used in industrial-scale fluidized bioreactors. Methods for ensuring reproducible results are described. To support the glucose consumption rate findings, biofilm dry weights were obtained at the conclusion of activity rate experiments, and scanning electron micrographs were taken to evaluate the presence of biofilm and to view surface characteristics. Fourteen different biofilm carriers were evaluated ranging …

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Enzyme–Microbe Synergy During Cellulose Hydrolysis By Clostridium Thermocellum, Yanpin Lu, Yi-Heng P. Zhang, Lee R. Lynd Oct 2006

Enzyme–Microbe Synergy During Cellulose Hydrolysis By Clostridium Thermocellum, Yanpin Lu, Yi-Heng P. Zhang, Lee R. Lynd

Dartmouth Scholarship

Specific cellulose hydrolysis rates (g of cellulose/g of cellulase per h) were shown to be substantially higher (2.7- to 4.7-fold) for growing cultures of Clostridium thermocellum as compared with purified cellulase preparations from this organism in controlled experiments involving both batch and continuous cultures. This “enzyme–microbe synergy” requires the presence of metabolically active cellulolytic microbes, is not explained by removal of hydrolysis products from the bulk fermentation broth, and appears due to surface phenomena involving adherent cellulolytic microorganisms. Results support the desirability of biotechnological processes featuring microbial conversion of cellulosic biomass to ethanol (or other products) in the absence of …

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The Effects Of Tgf-Beta1 And Igf-I On The Biomechanics And Cytoskeleton Of Single Chondrocytes, Nic Leipzig Oct 2006

The Effects Of Tgf-Beta1 And Igf-I On The Biomechanics And Cytoskeleton Of Single Chondrocytes, Nic Leipzig

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Objective Ascertaining how mechanical forces and growth factors mediate normal and pathologic processes in single chondrocytes can aid in developing strategies for the repair and replacement of articular cartilage destroyed by injury or disease. This study examined effects of transforming growth factor-β1 (TGF-β1) and insulin-like growth factor-I (IGF-I) on the biomechanics and cytoskeleton of single zonal chondrocytes. Method Superficial and middle/deep bovine articular chondrocytes were seeded on tissue culture treated plastic for 3 and 18 h and treated with TGF-β1 (5 ng/mL), IGF-I (100 ng/mL), or a combination of TGF-β1 (5 ng/mL) + IGF-I (100 ng/mL). Single chondrocytes from all …

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Designing A Nanotube Using Naturally Occurring Protein Building Blocks, Jie Zheng Oct 2006

Designing A Nanotube Using Naturally Occurring Protein Building Blocks, Jie Zheng

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Here our goal is to carry out nanotube design using naturally occurring protein building blocks. Inspection of the protein structural database reveals the richness of the conformations of proteins, their parts, and their chemistry. Given target functional protein nanotube geometry, our strategy involves scanning a library of candidate building blocks, combinatorially assembling them into the shape and testing its stability. Since self-assembly takes place on time scales not affordable for computations, here we propose a strategy for the very first step in protein nanotube design: we map the candidate building blocks onto a planar sheet and wrap the sheet around …

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Evaluation And Engineering Of Saccharomyces Cerevisiae For Cellulase Expression And Growth On Insoluble Cellulose, John Mcbride Sep 2006

Evaluation And Engineering Of Saccharomyces Cerevisiae For Cellulase Expression And Growth On Insoluble Cellulose, John Mcbride

Link Foundation Energy Fellowship Reports

The conversion of cellulosic biomass into fuels and chemicals promises to be a major revolution for the United States economy, but is dependent on the advancement of low-cost conversion technology. Of the natural resources available to human societies, biomass is one of the most abundant, and is the sole sustainable source of organic fuels, chemicals, and materials [1]. Biomass derived fuels and chemicals can achieve net zero carbon emissions on a lifecycle basis, provide substantial income to rural communities, and eliminate the security issues associated with fossil resources. Cellulosic biomass (wood, grass, agricultural residues, etc.) can be produced cheaply and …

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Magnetic Nanoparticle Supported Catalyst For Atom Transfer Radical Polymerization, Shijie Ding, Yangchuan Xing, Maciej Radosz, Youqing Shen Sep 2006

Magnetic Nanoparticle Supported Catalyst For Atom Transfer Radical Polymerization, Shijie Ding, Yangchuan Xing, Maciej Radosz, Youqing Shen

Chemical and Biochemical Engineering Faculty Research & Creative Works

Magnetic nanoparticles were used to support an ATRP catalyst for the polymerization of methyl methacrylate (MMA) for minimized adverse effect of catalyst support and easy catalyst separation. the nanoparticle-supported catalyst mediated a living/controlled radical polymerization of MMA as effectively as unsupported catalysts. with the addition of 22 mol % of CuBr 2, the polymer molecular weights were well-controlled with an initiator efficiency of 0.85 and polydispersity lower than 1.2. the supported catalysts could be easily separated/isolated using an external magnetic field and reused with slightly decreased activity but further improved control. the activity of the recycled catalyst was regenerated by …

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Electrochemical Durability Of Carbon Nanotubes In Noncatalyzed And Catalyzed Oxidations, Liang Li, Yangchuan Xing Sep 2006

Electrochemical Durability Of Carbon Nanotubes In Noncatalyzed And Catalyzed Oxidations, Liang Li, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

Noncatalyzed and catalyzed electrochemical oxidations of multiwalled carbon nanotubes (CNTs) were studied with the aim to understand their durability as catalyst support in polymer electrolyte membrane (PEM) fuel cells. Bare and Pt-deposited CNTs were investigated in 1.0 M sulfuric acid at a constant potential of 1.2 V. Carbon black (CB, Vulcan XC-72R) was also studied under the same experimental conditions. the carbons were oxidized at room temperature in the form of thin-film electrodes with time durations up to 48 h. Cyclic voltammetry was used to monitor the surface oxide redox reactions as a way to quantify the degree of surface …

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Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis Sep 2006

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Influence of two changes in the composition of a self-curing acrylic bone cement on some of its properties are discussed. Acrylic bone cements are widely used in orthopedic surgery for the fixation of joint prosthesis and in vertebroplasty and kyphoplasty for the stabilization and augmentation of fractured vertebrae. The cement's curing process is the result of a free-radical polymerization of a mixture of poly (methyl 1 methacrylate) [PMMA] containing powder and a liquid monomer that has methyl methacrylate (MMA) in it. It is initiated by the decomposition of benzoyl peroxide (BPO) in the powder, activated by a tertiary amine in …

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The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler Sep 2006

The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of ultrasonic setting on fluoride release from glass polyalkenoate cements (GPC) were investigated. Cements based on two different aluminosilicate glasses that contained silica, alumina, phosphate, and strontia were used for the experiment. A series of GPCs were examined to show that increased release F- ion occurs, regardless of GPC composition. The results show that there is a greater release of fluoride from the ultrasonically set samples than those set chemically, regardless of the chemical composition. The snap set caused by the ultrasound is likely to be due to a combination of cavitation, improved mixing of the constituents, …

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Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill Sep 2006

Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calcium and zinc ion release from hydroxyapatite-zinc oxide-poly (acrylic acid) (HAZnO-PAA) composite cements into deionised water was investigated as a function of HA content, PAA concentration, PAA molecular weight and maturation time. At any given maturation time, zinc ion release was constant until the HA content was at the maximum loading (60 wt%) resulting in the cement matrix breaking up, allowing exacerbated ion release. The calcium ion release increased with increased HA content in the composite until the maximum loading where the release drops off. Up to this point, the release of both ionic species was proportional to square root …

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Flow Regime Identification In A Bubble Column Based On Both Statistical And Chaotic Parameters Applied To Computed Tomography Data, Stoyan Nedeltchev, Ashfaq Shaikh, Muthanna H. Al-Dahhan Sep 2006

Flow Regime Identification In A Bubble Column Based On Both Statistical And Chaotic Parameters Applied To Computed Tomography Data, Stoyan Nedeltchev, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Kolmogorov Entropy (KE) Algorithm Was Applied Successfully to Single Source Γ-Ray Computed Tomography (CT) Data Measured in a 0.162 M ID Bubble Column Equipped with a Perforated Plate Distributor (163 Holes · Ø 1.32 Mm). Dried Air Was Used as the Gas Phase and Therminol LT (ΡL = 886 Kg M-3, ΜL = 0.88 · 10-3 Pa S, Σ = 17 · 10-3 N M-1) Was Used as a Liquid Phase. Three Different Pressures, P, of 0.1, 0.4, and 1.0 MPa Were Examined. at Each Pressure the Superficial Gas Velocity, UG, Was Increased Stepwise by Steps of 0.01 Ms-1 …

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Electrowetting Droplet Microfluidics On A Single Planar Surface, Christopher G. Cooney, Chao Yi Chen, Michael R. Emerling, Ali Nadim, James D. Sterling Sep 2006

Electrowetting Droplet Microfluidics On A Single Planar Surface, Christopher G. Cooney, Chao Yi Chen, Michael R. Emerling, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Electrowetting refers to an electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on a surface. Most designs ground the droplet by either sandwiching the droplet with a grounding plate on top or by inserting a wire into the droplet. Washizu and others have developed systems capable of generating droplet motion without a top plate while allowing the droplet potential to float. In contrast to these designs, we demonstrate an electrowetting system in which the droplet can be electrically grounded from below using thin conductive lines on top of the dielectric layer. This alternative method of …

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Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor Jun 2006

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

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The Antibacterial Effects Of Zinc Ion Migration From Zinc-Based Glass Polyalkenoate Cements, D. Boyd, H. Li, D. A. Tanner, Mark R. Towler, J. G. Wall Jun 2006

The Antibacterial Effects Of Zinc Ion Migration From Zinc-Based Glass Polyalkenoate Cements, D. Boyd, H. Li, D. A. Tanner, Mark R. Towler, J. G. Wall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Zinc-based glass polyalkenoate cements have been synthesised and their potential use in orthopaedic applications investigated. Zinc ions were released from the materials in a rapid burst over the first 24 h after synthesis, with the release rate falling below detectable levels after 7 days. Cement-implanted bone samples were prepared, and the released zinc was shown, using energy dispersive X-ray analysis, to penetrate from the cement into the adjacent bone by up to 40 μm. Finally, the cements exhibited antibacterial activity against Streptococcus mutans and Actinomyces viscosus that reflected the pattern of zinc release, with the inhibition of growth greatest shortly …

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Methane Production In A 100-L Upflow Bioreactor By Anaerobic Digestion Of Farm Waste, Abhijeet P. Borole, K. Thomas Klasson, Whitney Ridenour, Justin Holland, Khursheed Karim, Muthanna H. Al-Dahhan Jun 2006

Methane Production In A 100-L Upflow Bioreactor By Anaerobic Digestion Of Farm Waste, Abhijeet P. Borole, K. Thomas Klasson, Whitney Ridenour, Justin Holland, Khursheed Karim, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Manure Waste from Dairy Farms Has Been Used for Methane Production for Decades, However, Problems Such as Digester Failure Are Routine. the Problem Has Been Investigated in Small Scale (1-2 L) Digesters in the Laboratory; However, Very Little Scale-Up to Intermediate Scales Are Available. We Report Production of Methane in a 100-L Digester and the Results of an Investigation into the Effect of Partial Mixing Induced by Gas Upflow/recirculation in the Digester. the Digester Was Operated for a Period of About 70 D (With 16-D Hydraulic Retention Time) with and Without the Mixing Induced by Gas Recirculation through an Internal …

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Efficient, Thermally Stable, Second Order Nonlinear Optical Response In Organic Hybrid Covalent/Ionic Self-Assembled Films, Kevin E. Van Cott May 2006

Efficient, Thermally Stable, Second Order Nonlinear Optical Response In Organic Hybrid Covalent/Ionic Self-Assembled Films, Kevin E. Van Cott

Papers in Biomolecular Engineering

A covalent/electrostatic layer-by-layer self-assembly method was used to achieve polar ordering of a water soluble, reactive dye in the fabrication of nonlinear optical (NLO) films. We observed a quadratic relationship between the second harmonic intensity I2 and bilayer number for all films made with Procion Brown MX-GRN, demonstrating that the polar ordering of the chromophores is consistent in each successive bilayer. As the ionic strength of the dye deposition solution was increased to 0.5 M NaCl, the of the films increased by approximately 250% to 50 × 10-9 esu, with a corresponding average chromophore tilt angle of 38. This was …

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Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall May 2006

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

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Thermal Analysis Of Adsorbed Poly(Methyl Methacrylate) On Silica, Frank D. Blum, Erin N. Young, Gregory Smith, Oliver C. Sitton May 2006

Thermal Analysis Of Adsorbed Poly(Methyl Methacrylate) On Silica, Frank D. Blum, Erin N. Young, Gregory Smith, Oliver C. Sitton

Chemistry Faculty Research & Creative Works

Modulated differential scanning calorimetry has been used to quantify the glass transitions of small, adsorbed amounts of poly (methyl methacrylate) (PMMA) on silica. While a relatively narrow, single glass transition was found for bulk PMMA, broader two-component transitions were found for the adsorbed polymer. a two-state model based on loosely bound polymer (glass transition similar to bulk) and more tightly bound polymer (glass transition centered around 156°C) was used to interpret the thermograms. on the basis of this model, the amount of tightly bound polymer was found to be approximately 1.3 mg/m 2, corresponding to a 1.1 nm thick layer. …

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An Investigation Into The Structure And Reactivity Of Calcium-Zinc-Silicate Ionomer Glasses Using Mas-Nmr Spectroscopy, D. Boyd, Mark R. Towler, R. V. Law, R. G. Hill May 2006

An Investigation Into The Structure And Reactivity Of Calcium-Zinc-Silicate Ionomer Glasses Using Mas-Nmr Spectroscopy, D. Boyd, Mark R. Towler, R. V. Law, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Polyalkenoate Cements (GPCs) for orthopaedic applications is retarded by the presence in the glass phase of aluminum, a neurotoxin. Unfortunately, the aluminum ion plays an integral role in the setting process of GPCs and its absence is likely to hinder cement formation. However, the authors have previously shown that aluminum-free GPCs may be formulated based on calcium zinc silicate glasses and these novel materials exhibit significant potential as hard tissue biomaterials. However, there is no data available on the structure of these glasses. 29Si MAS-NMR, differential thermal analysis (DTA), X-ray diffraction (XRD), and network crosslink density …

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Gas Holdup In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan Apr 2006

Gas Holdup In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Sectionalization of Conventional Bubble Columns by Perforated Trays into Trayed Bubble Columns (TBCs) Has Much Potential in Biochemical and Petroleum Refining Processes, as an Effective Way to Improve the Gas-Liquid Contacting Efficiency and Reduce the Liquid Back mixing. in This Work, the Effects of Tray Geometry, Superficial Gas Velocity, and Superficial Liquid Velocity on the overall Gas Holdup Have Been Investigated. It Was Determined that the Trays Significantly Increase the overall Gas Holdup. the Tray Hole Diameter and Superficial Gas Velocity Were Determined to Be the Most Important Factors. © 2006 American Chemical Society.

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Ultrasonically Set Glass Polyalkenoate Cements For Orthodontic Applications, D. A. Tanner, N. Rushe, Mark R. Towler Apr 2006

Ultrasonically Set Glass Polyalkenoate Cements For Orthodontic Applications, D. A. Tanner, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is an accepted clinical requirement for a luting cement that can be command set upon satisfactory placement of an orthodontic appliance onto dentition. This work evaluates the suitability of ultrasound, imparted from a dental scaler, as a potential mechanism for achieving this. The net setting times and subsequent compressive strengths of a range of commercial and experimental glass polyalkenoate cements (GPCs) were evaluated, using modified ISO 9917 methods, when set both chemically and by ultrasound. The ultrasound was applied to the GPC through an orthodontic brace. It was possible to command set GPCs by the application of five to …

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Optimisation Of The Composition Of An Acrylic Bone Cement: Application To Relative Amounts Of The Initiator And The Activator/Co-Initiator In Surgical Simplex®P, S. Madigan, M. R. Towler, G. Lewis Apr 2006

Optimisation Of The Composition Of An Acrylic Bone Cement: Application To Relative Amounts Of The Initiator And The Activator/Co-Initiator In Surgical Simplex®P, S. Madigan, M. R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In cemented arthroplasties, the two-part self-curing acrylic bone cement is currently the only material used for anchoring the total joint replacement to the contiguous bone. In virtually all commercially available formulations of this cement, the agents used for the initiation and activation/co-initiation of the radical polymerisation reaction are benzoyl peroxide (BPO) and N, N dimethyl-paratoluidine (DMPT), respectively. There are no reports in the open literature on the rationale for the amounts of these and other constituents in the formulations of the cement. Given the concerns that have been raised in the literature regarding the effect of residual DMPT on the …

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Use Of A Modified Zirconia Support In The Separation Of Immunoproteins, Anuradha Subramanian, Sabyasachi Sarkar Mar 2006

Use Of A Modified Zirconia Support In The Separation Of Immunoproteins, Anuradha Subramanian, Sabyasachi Sarkar

Papers in Biotechnology

Zirconia beads (25–38 μm in diameter) were modified with N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid to generate a zirconia based pseudoaffinity support, further referred to as r_PEZ. The influence of pH, salt concentration and temperature on the binding of human immunoglobulin G (hIgG) to r_PEZ was studied. Temperature had no significant impact on the maximum binding capacity (Qmax), and the equilibrium-binding constant (Kd), whereas pH and the salt concentration had a noticeable impact on both Qmax and Kd. The Qmax value of 55 mg hIgG/ml of bead was obtained at a pH of 5.5 and found to decrease with an increase of pH. The …

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A Comparative Study Of Monoclonal Antibodies (Mabs) Purified From Cell Culture Supernatant On Edtpa-Modified Zirconia Beads And Protein A-Hyper D Support, Anuradha Subramanian, Blanca Martinez, Jill Holm, Peter W. Carr, Clayton V. Mcneff Mar 2006

A Comparative Study Of Monoclonal Antibodies (Mabs) Purified From Cell Culture Supernatant On Edtpa-Modified Zirconia Beads And Protein A-Hyper D Support, Anuradha Subramanian, Blanca Martinez, Jill Holm, Peter W. Carr, Clayton V. Mcneff

Papers in Biotechnology

Colloidal zirconia was spray dried to yield zirconia particles, which were further modified with N, N, N0, N0- Ethylenediamine tetra methylenephosphonic acid (EDTPA) to yield a sup-port for use in bioseparations. EDTPA modified zirconia particles will be further referred to as, r_PEZ. Cell culture supernatants rich in monoclonal antibody (Mab) subtypes IgG1, IgG2a, IgG2b, and IgG3 were chromatographed on a r_PEZ column, and on a protein A-hyper D col-umn that was purchased commercially. All Mab subtypes bound to r_PEZ and process yields in the range of 88 to 99% were obtained. The purity of the Mab products were ascertained by …

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Liquid Phase Mixing In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan Mar 2006

Liquid Phase Mixing In Trayed Bubble Column Reactors, Javier Alvaré, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Compartmentalization of Conventional Bubble Columns by Perforated Trays Constitutes a Very Effective Method to Reduce the Liquid Back mixing. the Effect of Tray Design and Operating Conditions on the overall Liquid Mixing Was Studied in a Bench-Scale Trayed Bubble Column. the Extent of Liquid Back mixing in the Column Was Investigated in Light of Liquid-Phase Tracer Response Experiments. in Average, a Three-Fold Reduction in the Liquid Back mixing Was Achieved in the Trayed Column as Compared to the Column Without the Trays. Moreover, the Tray Open Area and the Superficial Liquid Velocity Were Found to Have the Strongest Effects …

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The Comet Assay To Determine The Mode Of Cell Death For The Ultrasonic Delivery Of Doxorubicin To Human Leukemia (Hl-60 Cells) From Pluronic P105 Micelles, Ghaleb A. Husseini, Kim L. O'Neill, William G. Pitt Feb 2006

The Comet Assay To Determine The Mode Of Cell Death For The Ultrasonic Delivery Of Doxorubicin To Human Leukemia (Hl-60 Cells) From Pluronic P105 Micelles, Ghaleb A. Husseini, Kim L. O'Neill, William G. Pitt

Faculty Publications

This notes examines the mode of cell death of HL-60 cells exposed to 70 kHz and 1.3 W/cm2 in the presence of 1% Pluronic P105 and 1.67 μg/ml doxorubicin (Dox). The cells were ultrasonicated for 30, 60 and 120 minutes. They were then lysed, electrophorised, stained using propidium iodide, and their DNA profile captured using a fluorescent microscope. The gradual DNA damage observed and the comet tails captured after 1 and 2 hours of insonation suggest that the mode of cell killing is apoptosis.

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Phase Distribution In An Upflow Monolith Reactor Using Computed Tomography, M. (Muthanna) H. Al-Dahhan, A. Kemoun, A. R. Cartolano Feb 2006

Phase Distribution In An Upflow Monolith Reactor Using Computed Tomography, M. (Muthanna) H. Al-Dahhan, A. Kemoun, A. R. Cartolano

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computed Tomography (CT) is Known to Be a Viable Technique for Determining Flow Maldistribution in Two-Phase Flow through Packed Beds. in This Study, Gamma Ray Computed Tomography Has Been Used to Quantify the Flow Distribution in a Monolith Catalytic Bed, with Water as the Liquid Phase and Air as the Gas Phase, Flowing Co-Currently Upward. the Flow Conditions Were Selected to Bracket Some Commercially Viable Operating Conditions for Such Reactors. in the Monolith Core Region, Fairly Uniform Flow Distribution Has Been Obtained for All the Flow Conditions Used. This Distribution is Quantified using the Standard Deviation of the Holdup Distribution. …

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Ultrafiltration Membrane Process For Pyrogen Removal In The Preparation Of Water For Injection (Wfi), Thet N. Soe Jan 2006

Ultrafiltration Membrane Process For Pyrogen Removal In The Preparation Of Water For Injection (Wfi), Thet N. Soe

Inquiry: The University of Arkansas Undergraduate Research Journal

An artificial kidney process based on ultrafiltration (called hemodiafiltration) more effectively removes blood toxins, particularly those of higher molecular weight, than conventional dialysis. In hemodiafiltration, replacement liquid must be added directly to the patient's blood to replace liquid filtered out of the blood in the ultrafiltration cartridge. This replacement liquid is made up of' "water for injection" (WFI) and other components such as salts and glucose. WFI is produced either by distillation or reverse osmosis and has a cost of $1.00 per liter. A patient with kidney problems would require three hemodiafiltration treatments per week, each requiring 70-80 liters of …

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Nanoparticles For Enhanced Delivery Of Chemotherapeutics, Emily J. Bahram-Ahi Jan 2006

Nanoparticles For Enhanced Delivery Of Chemotherapeutics, Emily J. Bahram-Ahi

Opportunities for Undergraduate Research Experience Program (OURE)

Delivery of the anticancer drug paclitaxel (commercially known as Taxol®) is difficult due to its limited solubility in aqueous media. This study proposes a novel bubble bursting technique to generate nanoparticles of the chemotherapeutic in an effort to decrease potential side effects and improve the bioavailability of hydrophobic drugs. The bubble bursting apparatus will be used to produce nanoparticles of a biodegradable polymer, poly(lactide-co-glycolide) (PLGA), as carriers for paclitaxel. The dissolved paclitaxel in this biodegradable polymer matrix will be released at a controlled rate for a more efficient delivery of the drug throughout the body.

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