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

Engineering Commons

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

Articles 1 - 8 of 8

Full-Text Articles in Engineering

Biomass Reburning For Control Of Nitrogen Oxides , Jeffrey James Sweterlitsch Jan 2002

Biomass Reburning For Control Of Nitrogen Oxides , Jeffrey James Sweterlitsch

Retrospective Theses and Dissertations

Fuel-Lean Gas Reburning(TM) (FLGR) is a method of controlling NO x emissions produced during coal combustion in utility boilers by injecting natural gas into the boiler downstream of the primary combustion zone. Whereas traditional reburning requires 10%--20% of the total energy input from the reburn fuel followed by over-fire air to complete combustion of fuel fragments, FLGR uses only 5%--10% of the total energy input from the reburn fuel. Because less fuel is used, the overall environment in the boiler remains fuel-lean, with only localized eddies that are fuel-rich, where the NOx reduction takes place. FLGR does ...


Development Of Novel Polymeric Materials For Gene Therapy And Ph-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, And Analysis , Brian Curtis Anderson Jan 2002

Development Of Novel Polymeric Materials For Gene Therapy And Ph-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, And Analysis , Brian Curtis Anderson

Retrospective Theses and Dissertations

The aim of this work was to obtain a fundamental understanding of drug release mechanisms from polymers that undergo thermoreversible gelation and to synthesize new polymers based on these that exhibit both pH and temperature sensitivity. Novel block and random copolymers with cationic character have been developed for drug delivery and gene therapy applications. The development of these materials began with a study of the mechanism of drug release from poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) block copolymers. This study revealed the release rates of drugs from water-soluble hydrogels composed of the PEO-PPO-PEO block copolymer PluronicRTM F127 ...


Recovery Of Recombinant Proteins From Transgenic Plants: Strategies In Implementation And Optimization , Todd J. Menkhaus Jan 2002

Recovery Of Recombinant Proteins From Transgenic Plants: Strategies In Implementation And Optimization , Todd J. Menkhaus

Retrospective Theses and Dissertations

Strategies to optimize the recovery of recombinant proteins from plant hosts have been investigated. The use of different crops, different product molecules, and different separation techniques was studied to suggest modes of operation that reduce the overall processing cost for obtaining purified recombinant proteins from plants.;Polyelectrolyte precipitation of beta-glucuronidase (GUS), an acidic model protein, with polyethyleneimine (PEI), a polycatonic polymer, from the extracts of canola, corn germ, soybean, and pea met with varying degrees of success. Precipitation from canola required the least amount of PEI and was capable of providing the highest enrichment. In contrast, soy and pea allowed ...


Mechanistic Understanding Of Miscibility Effects On Fracture Strength Of Polymer Interfaces , Russell E. Gorga Jan 2002

Mechanistic Understanding Of Miscibility Effects On Fracture Strength Of Polymer Interfaces , Russell E. Gorga

Retrospective Theses and Dissertations

This research has provided a fundamental framework based on both experiment and theory to understand the fracture behavior as a function of system miscibility for nonreinforced polymer interfaces. The system chosen for study was polystyrene (PS) and the statistically random copolymer poly (styrene-r-4-bromostyrene) (PBS), where the volume fraction of bromine in the copolymer, f, and the degree of polymerization, N, control the miscibility. The phase behavior of thin film blends of PS and PBS as a function of f and N was studied using atomic force microscopy (AFM) and small angle X-ray scattering (SAXS). Simulations based on the Flory-Huggins theory ...


Investigation Of Napl Dissolution And Instability Using A Pore-Scale Network Model: Sensitivity Analysis Of Porous Medium Characteristics , Yanhui Hu Jan 2002

Investigation Of Napl Dissolution And Instability Using A Pore-Scale Network Model: Sensitivity Analysis Of Porous Medium Characteristics , Yanhui Hu

Retrospective Theses and Dissertations

Nonaqueous phase liquids (NAPLs) introduced into an aquifer can cause long-term contamination. While some of the NAPL may be recoverable, most will dissolve into the surrounding water over a period of years or centuries. A three-dimensional pore-scale network model was developed to investigate the NAPL dissolution process in porous media. The model explicitly investigated two dissolution mechanisms: stagnant layer diffusion and channel flow dissolution. Numerical experiments were conducted to determine the effects of ganglion size, aqueous phase flow rate, and porous medium characteristics on the NAPL dissolution rate, ganglion configuration, and ganglion instability, both initial and dissolution-induced. It was found ...


Interdiffusion Phenomena At Partially Miscible Polymer Interfaces , Erin Lynne Jablonski Jan 2002

Interdiffusion Phenomena At Partially Miscible Polymer Interfaces , Erin Lynne Jablonski

Retrospective Theses and Dissertations

This research is focused on understanding the effect of miscibility on interdiffusion phenomena in bilayers of polystyrene (PS) and the statistically random copolymer, poly (styrene-r-4-bromostyrene) (PBS). Miscibility in such systems can be quantified by N*chi, where N* is an effective degree of polymerization and chi the Flory-Huggins interaction parameter. In the PS/PBS system, miscibility decreases as N *chi increases. The extent of interdiffusion at a bilayer interface is ultimately determined by the miscibility of the system. A description of the effect of miscibility on interdiffusion phenomena, interfacial width, phase behavior, and fracture energy and a relationship between these ...


Effects Of Fly Ash On The Oxidation Of Mercury During Post-Combustion Conditions , Hongqun Yang Jan 2002

Effects Of Fly Ash On The Oxidation Of Mercury During Post-Combustion Conditions , Hongqun Yang

Retrospective Theses and Dissertations

Mercury emissions from coal-fired power plants pose impact on human health. The emissions will be regulated in the near future. Mercury speciation in flue gas has an important effect on the efficiency of mercury emission control devices. This study focuses on the role of fly ash on the oxidation of Hg 0 in bench-scale simulated flue gas environment and in laboratory-scale coal combustion flue gas environment. The effects of flue gas matrices, temperature, fly ash mineralogy and morphology on the oxidation of Hg0 are studied. Conclusions are drawn based on the testing results: (1) Mercury chemistry is very complex in ...


A Study Of Rheology, Processing And Phase Behavior Of Engineered Inorganic Glass-Organic Polymer Hybrid Materials , Peter Christopher Guschl Jan 2002

A Study Of Rheology, Processing And Phase Behavior Of Engineered Inorganic Glass-Organic Polymer Hybrid Materials , Peter Christopher Guschl

Retrospective Theses and Dissertations

Due to the consequence of expensive development costs that arise with manufacturing and synthesizing new polymers, interest in polymer blends has gained considerable attention in recent years. It is well known that the production of miscible and immiscible blends of polymers can lead to composite materials with special chemical, thermal, mechanical, and rheological properties. The morphology of immiscible polymer blends arises during mixing and is affected by the processing conditions, particular interactions, and the interfacial tension and viscosity ratio between the components. The significance of the interfacial energy between the blend components and its inherent effect on the rheology is ...