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Full-Text Articles in Engineering

Plasma Catalysis Using Low Melting Point Metals., Maria Carreon Dec 2015

Plasma Catalysis Using Low Melting Point Metals., Maria Carreon

Electronic Theses and Dissertations

Plasma catalysis is emerging as one of the most promising alternatives to carry out several reactions of great environmental importance, from the synthesis of nanomaterials to chemicals of great interest. However, the combined effect of a catalyst and plasma is not clear. For the particular case of 1-D nanomaterials growth, the low temperatures synthesis is still a challenge to overcome for its scalable manufacturing on flexible substrates and thin metal foils. Herein, the use of low-melting-point metal clusters under plasma excitation was investigated to determine the effectiveness in their ability to catalyze the growth of 1-D nanomaterials. Specifically, plasma catalysis …


Heat Transfer Mechanisms In Water-Based Nanofluids., Masoudeh Ahmadi Dec 2015

Heat Transfer Mechanisms In Water-Based Nanofluids., Masoudeh Ahmadi

Electronic Theses and Dissertations

Nanofluids are a class of heat transport fluids created by suspending nano-scaled metallic or nonmetallic particles into a base fluid. Some experimental investigations have revealed that the nanofluids have remarkably higher thermal conductivities than those of conventional pure fluids and are more suited for practical application than the existing techniques of heat transfer enhancement using millimeter and/or micrometer-sized particles in fluids. Use of nanoparticles reduces pressure drop, system wear, and overall mass of the system leading to a reduction in costs over existing enhancement techniques. In this work, the heat transfer coefficient is determined experimentally using copper oxide (CuO) based …


New Visible Light Absorber For Solar Fuels : Ga(Sbx)N1-X Alloys., Swathi Sunkara Dec 2015

New Visible Light Absorber For Solar Fuels : Ga(Sbx)N1-X Alloys., Swathi Sunkara

Electronic Theses and Dissertations

Solar energy conversion to fuels via photoelectrochemical water splitting is one of the most important technological directions toward meeting the global energy and environmental challenge. However, till date, there are no suitable semiconductor materials available that can absorb visible light, possess right kind of band edge energetics and are stable in aqueous environments. In this work, a new III-V alloy material Ga(Sbx)N1-x with dilute antimony concentration is proposed and developed for photoelectrochemical water splitting. Experimental studies were conducted first to synthesize the proposed alloy materials to understand structure-property relationships and compare them to those obtained using first principles computations. Finally, …


Model Of A Tubular Perfusion Bioreactor Using Computational Fluid Dynamics., Matthew James Robeson 1991- Jul 2015

Model Of A Tubular Perfusion Bioreactor Using Computational Fluid Dynamics., Matthew James Robeson 1991-

Electronic Theses and Dissertations

Through recent years, many novel bioreactor designs for tissue engineering have emerged. The Tubular Perfusion System (TPS) is one such bioreactor for bone and cartilage tissue engineering. The TPS is a perfusion type bioreactor, in which media flows through a bed of scaffold beads. The advantage of this system over similar designs is that it requires no special fabrication techniques and operates at low pressure. Experimental trials have shown increased osteoblastic differentiation and mineralization of bone tissue grown using the TPS versus static culture. The effectiveness of the TPS in promoting osteoblastic differentiation is believed to be due to enhanced …


Feasibility Testing Of Chill Filtration Of Brown Spirits To Increase Product Stability., Juan Cristobal Merizalde Carrillo May 2015

Feasibility Testing Of Chill Filtration Of Brown Spirits To Increase Product Stability., Juan Cristobal Merizalde Carrillo

Electronic Theses and Dissertations

This thesis summarizes a feasibility study focused on filtering American whiskey, matured in new toasted and charred casks, at 25 ºF in order to remove haze which forms when product is diluted from cask strength (62% ABV) to bottling strength (40 – 50% ABV). Chill filtration is a process already implemented in the brown spirits industry in order to guarantee the stability of products at different ethyl alcohol concentrations. The filtration trials and cellulose-pad performance were evaluated in terms of economics, turbidity reduction, test time, throughput, color reduction, and shelf life stability. Those trials with satisfactory overall color and stability …


Nanoscale Electrode Architectures For Electrochemical Energy Conversion And Storage., Venkat Kalyan Vendra May 2015

Nanoscale Electrode Architectures For Electrochemical Energy Conversion And Storage., Venkat Kalyan Vendra

Electronic Theses and Dissertations

Nanoscale electrode architectures are at the heart of photoelectrochemical devices converting sunlight into electricity and electrochemical devices that store energy. Advanced nanomaterials encompassing 1-D architectures such as single crystalline metal oxide nanowires, 2-D architectures such graphene nanosheets and nanoparticle-nanowire hybrids have garnered significant interest as promising materials for fabricating thicker electrodes due their unique electronic, phase transformation and strain relaxation properties. However, electrode architectures incorporating these advanced nanomaterials will have a transformational impact on large scale electrode manufacturing only if the challenges associated with the electrode durability are addressed. At a fundamental level, the reactions happening at the electrode-electrolyte interface …


The Production, Properties And Applications Of The Zinc Imidazolate, Zif-8., John L. Tatarko Jr. May 2015

The Production, Properties And Applications Of The Zinc Imidazolate, Zif-8., John L. Tatarko Jr.

Electronic Theses and Dissertations

Venna, Carreon, and Jasinski produced and characterized the first samples of the zinc imidazolate framework ZIF-8 at the University of Louisville in 2010. In this dissertation the production, properties, and applications of this unique metal-organic framework are explored. Previously, only minute laboratory amounts (1/4 gram), of ZIF-8 were produced via time-consuming and expensive processes. Production quantities have been synthesized via both a continuous and a batch process using a spray drying operation to effect separation of the solid product (ZIF-8) from the mother liquor. Approximately 85% of the mother liquor (methanol), can be recovered from the spray dryer resulting in …


Dosi In Novel Geometry Dishes, Jonathan Lawrence Lambert Jones Apr 2015

Dosi In Novel Geometry Dishes, Jonathan Lawrence Lambert Jones

Electronic Theses and Dissertations

Effects of hemodynamic forces on cellular response are well studied. Wall shear stress is regularly accepted as the primary hemodynamic force affecting cellular response. Hemodynamic forces studies utilize Petri dishes on orbital shakers to grow cells for the experiments since this is an easily scalable system. However, characterizing the hemodynamics is difficult since the oscillatory swirling motion creates multidirectional and variable magnitude shear throughout the dish. Thus, a novel geometry dish that could create uniaxial shear with less variation in magnitude would be advantageous for studying shear stress effects on cellular response. The purpose of this thesis was to explore …


Carbon Dioxide Capture With Amine Functionlized Graphene Oxide, Renee Zeleszki Jan 2015

Carbon Dioxide Capture With Amine Functionlized Graphene Oxide, Renee Zeleszki

Electronic Theses and Dissertations

Abstract: amine functionalized graphene oxide was used as sorbent in order to achieve carbon dioxide capture. In this study, micro size graphite flakes was prepared according to modified hummers method and "hummers' method with additional kmno4." Graphene oxide was then functionalized with ethylenediamine (eda). Different purification methods for graphene oxide were studied as well as different functionalization method times. Graphite oxide and functionalized graphene oxide has been analyzed with fourier transform infrared spectroscopy (ftir) for chemical structure. Thermal gravimetric analysis (tga) was used to test co2 capture capacity. Functionalized graphene oxide that has been purified with 30 washes via centrifuge …


Synthetic Materials With Redox-Triggers For Imaging And Drug Delivery, Jungeun Bae Jan 2015

Synthetic Materials With Redox-Triggers For Imaging And Drug Delivery, Jungeun Bae

Electronic Theses and Dissertations

Synthetic materials embedded with stimuli-responsive cleavable bonds have been extensively utilized for the development of site-targeted drug delivery system and selective imaging reporters. We developed stimuli-sensitive materials with two different redox switches including trimethyl-locked quinone propionic acid and nitrobenzyl moieties. Novel redox-sensitive polymeric nanoparticles and micelles were prepared from a synthesized monomer containing trimethyl-locked quinone propionic acid as a redox trigger. A hydrophobic cancer drug, Paclitaxel, was incorporated into the redox-responsive polymeric nanoparticles and micelles prepared from the synthesize polymers. The effect of redox stress on the nanoparticles and micelles was evaluated with a chemical reductant, sodium dithionite demonstrating that …