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Articles 1 - 11 of 11

Full-Text Articles in Engineering

Engineering Polyanhydride Microspheres For The Stabilization And Controlled Release Of Proteins , Amy Sywassink Determan Jan 2006

Engineering Polyanhydride Microspheres For The Stabilization And Controlled Release Of Proteins , Amy Sywassink Determan

Retrospective Theses and Dissertations

This work investigates the use of polyanhydride microspheres as drug delivery carriers for therapeutic proteins. The polymers investigated are poly(sebacic anhydride) and opolymers of poly[1,6-bis(p-carboxyphenoxy)hexane] (poly(CPH)) and poly(SA), 20:80 (CPH:SA), 50:50 (CPH:SA), and 80:20 (CPH:SA). The model protein bovine serum albumin (BSA) was encapsulated in poly(SA), 20:80 (CPH:SA), 50:50 (CPH:SA), and 80:20 (CPH:SA) microspheres to determine the feasibility of using polyanhydrides as protein carriers. Poly(SA) and 20:80 (CPH:SA) were found to stabilize the encapsulated BSA and were ...


Multicomponent Drying Of Semicrystalline Polymers , Sim-Siong Wong Jan 2006

Multicomponent Drying Of Semicrystalline Polymers , Sim-Siong Wong

Retrospective Theses and Dissertations

The focus of this research is to gain a better understanding of multicomponent drying behavior of semicrystalline polymers. A combination of experimental and theoretical approaches was used in this work. A mathematical model involving free-volume theory and solvent-induced crystallization kinetics as the backbone was developed to examine the complex relationship between polymers and solvents during drying. External conditions such as temperature, external mass transfer rate and film shrinkage were considered. A poly(vinyl alcohol)/water/methanol test system was chosen. The parametric studies of the model show that it can be adapted for wide range of initial and operating conditions ...


Computational Fluid Dynamics Simulation Of Fluidized Bed Polymerization Reactors , Rong Fan Jan 2006

Computational Fluid Dynamics Simulation Of Fluidized Bed Polymerization Reactors , Rong Fan

Retrospective Theses and Dissertations

In this research, a CFD algorithm for simulation of fluidized bed polymerization reactors is described. In order to properly model the evolution of a polydisperse solid phase, population balance equation (PBE) must be solved along with other transport equations. A novel approach---DQMOM is applied to polydisperse fluidized bed to simulate particle aggregation and breakage in the reactors. Two different aggregation and breakage kernels are tested and the performance of the DQMOM approximation with different numbers of nodes are compared. Results show that the approach is very effective in modeling solid segregation and elutriation and in tracking the evolution of the ...


Computational Methods In The Study Of Carbohydrates And Carbohydrate-Active Enzymes , Anthony David Hill Jan 2006

Computational Methods In The Study Of Carbohydrates And Carbohydrate-Active Enzymes , Anthony David Hill

Retrospective Theses and Dissertations

Carbohydrates are important molecules in energy storage and cellular recognition. New methods are used and discussed to capture important structural details of created by the protein/carbohydrate interactions. In particular, the thermodynamics of carbohydrate binding are explored, and a new model to accurately calculate the free energy of binding is developed. Additionally, a new method of describing the pucker of carbohydrate ring with three coordinates is discussed. These methods are then applied to Family 1 Glycoside Hydrolases.


Carbon-13 Metabolic Flux Analysis Of Soybean Central Carbon Metabolism: Response To Temperature And Genotype Effects , Vidya Vaancheeswaran Iyer Jan 2006

Carbon-13 Metabolic Flux Analysis Of Soybean Central Carbon Metabolism: Response To Temperature And Genotype Effects , Vidya Vaancheeswaran Iyer

Retrospective Theses and Dissertations

Soybeans are a major source of high quality protein, edible oil, food products, and also several industrial non food applications such as paper coating, textiles and plastics. It is difficult to develop soybeans with high protein and high oil, however, due to the inverse relationship between these two components. Consequently, increasing seed protein concentration without adversely affecting the yield and oil content has been difficult to achieve. It has been demonstrated that the temperature and genotype of soybeans influence the protein or lipid composition considerably. However, the interactions between various pathways responsible for the changes in the composition are unknown ...


A Comprehensive Dynamic Model For High-Pressure Tubular Low-Density Polyethylene (Ldpe) Reactors , Mothivel B. Mummudi Boopathy Jan 2006

A Comprehensive Dynamic Model For High-Pressure Tubular Low-Density Polyethylene (Ldpe) Reactors , Mothivel B. Mummudi Boopathy

Retrospective Theses and Dissertations

Low-density polyethylene (LDPE) is a versatile polymer which is widely used both in domestic and industrial applications. About 50% of commercial LDPE production around the world is carried out by free-radical polymerization initiated by organic peroxides in high-pressure tubular reactors. The free-radical polymerization is highly sensitive to even small changes in process conditions. As a result, the extreme pressures and temperatures in the high-pressure tubular LDPE reactor (HPTLR) present operational challenges to the plant engineer. A reliable model of the HPTLR will prove to be a valuable tool for the plant engineer in making decisions about reactor operations;In this ...


Directed Growth And Selective Differentiation Of Neural Progenitor Cells Using A Synergistic Combination Of Topographical And Soluble Cues , Jennifer Behr Recknor Jan 2006

Directed Growth And Selective Differentiation Of Neural Progenitor Cells Using A Synergistic Combination Of Topographical And Soluble Cues , Jennifer Behr Recknor

Retrospective Theses and Dissertations

The purpose of this study is to develop strategies to facilitate nerve regeneration using a synergistic combination of guidance cues. We are investigating the cellular mechanisms of development using adult rat hippocampal progenitor cells (AHPCs) and have demonstrated that manipulating a combination of physical, chemical and biological cues can lead to oriented astrocyte and neural progenitor cell outgrowth and can influence progenitor cell differentiation. To provide physical guidance, micropatterned polystyrene (PS) substrates were fabricated and chemically modified with laminin. Astrocytes or AHPCs cultured on these substrates align along the grooves of the patterned surface extending highly elongated processes. To further ...


Recovery Of Monosaccharides Via Catalytic Hydrolysis , Jason Alan Bootsma Jan 2006

Recovery Of Monosaccharides Via Catalytic Hydrolysis , Jason Alan Bootsma

Retrospective Theses and Dissertations

This research has provided a fundamental analysis of the use of novel separation and catalyst techniques for saccharification of lignocellulosic tissues. Separation techniques focused on providing a feedstock that was more amenable to hydrolysis. Catalyst development focused on solid acid materials that would provide processing advantages, cost reductions, and waste reduction. A mechanical separation technique was used on corn stover to separate the parent material into two streams with improved processing characteristics. The desire was to produce a material that was easier to hydrolyze in addition to producing a material with enhanced fiber character. The separation technique was effective; however ...


Recovery And Purification Of Recombinant Protein From Transgenic Corn By Aqueous Two-Phase Partitioning , Zhengrong Gu Jan 2006

Recovery And Purification Of Recombinant Protein From Transgenic Corn By Aqueous Two-Phase Partitioning , Zhengrong Gu

Retrospective Theses and Dissertations

Aqueous two-phase (ATP) partitioning was paired in a variety of ways to use of transgenic corn for protein expression. Systems were developed to selectively partition corn proteins from classes of potential recombinant proteins as well as the specific case of dog gastric lipase. More fundamentally, ATP partitioning was used to expand 2D gel electrophoretic characterization of protein size and pI to the third dimension of hydrophobicity with the usefulness of the method illustrated for corn extracts;ATP partitioning in polyethylene glycol (PEG)-salt systems separates proteins primarily according to their surface hydrophobicity differences. The average hydrophobicity of pH 7 extracts ...


Vibration-Induced Mobilization Of Trapped Non-Aqueous Phase Liquids In Porous Media , Wenqing Li Jan 2006

Vibration-Induced Mobilization Of Trapped Non-Aqueous Phase Liquids In Porous Media , Wenqing Li

Retrospective Theses and Dissertations

Acoustic wave stimulation, such as vibration-induced mobilization, is a promising enhancement approach to remove trapped NAPLs (Non-Aqueous Phase Liquids) usually encountered in multiphase flows through porous media, especially the remediation of underground water contamination and incomplete petroleum recovery from oil reservoirs, with advantages of high efficiency, low cost and environmental safety relative to traditional mobilization methods;According to a simple hypothesized capillary-physics mechanism, specific predictions can be deduced that vibration will be the most effective in mobilizing trapped non-aqueous phase liquids with a comparative higher acceleration amplitude and lower vibration frequency;Quasi-two-dimensional glass micro-model experiments were carried out and it ...


Synthesis And Characterization Of Stimuli Responsive Block Copolymers, Self-Assembly Behavior And Applications , Michael Duane Determan Jan 2006

Synthesis And Characterization Of Stimuli Responsive Block Copolymers, Self-Assembly Behavior And Applications , Michael Duane Determan

Retrospective Theses and Dissertations

Water-soluble stimuli responsive block copolymers are a rapidly emerging class of materials with great potential in biomedical and technological applications. In this work a novel class of pentablock copolymers are synthesized via atom transfer radical polymerization techniques and their stimuli-responsive self-assembly properties are characterized. Aqueous solutions of these materials are observed to form micelles and hydrogels in response to changes in both temperature and pH. Cryogenic transmission electron microscopy (cryo-TEM) and small angle neutron and X-ray scattering (SANS and SAXS) techniques are used to investigate the nanoscale structures formed by these pentablock copolymers in solution. The gel structure and mechanical ...