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Full-Text Articles in Engineering

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin Dec 2017

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin

Electronic Theses and Dissertations

Gas analysis is an important part of our world and gas sensing technology is becoming more essential for various aspects of our life. A novel approach for gas mixture analysis by using portable gas chromatography in combination with an array of highly integrated and selective metal oxide (MOX) sensors has been studied. We developed a system with small size (7 x 13 x 16 inches), low power consumption (~10 W) and absence of special carrier gases designed for portable field analysis (assuming apriori calibration). Low ppb and even sub-ppb level of detection for some VOCs was achieved during the analysis …


A Comparison Of Mean Age Theory And Residence Time Distributions In Mixed Systems., Nolan Theaker Dec 2017

A Comparison Of Mean Age Theory And Residence Time Distributions In Mixed Systems., Nolan Theaker

Electronic Theses and Dissertations

A comparison between mean age theory and conventional residence time distributions over a range of quantified mixing levels was conducted using computational fluid dynamics (CFD). The system was a stirred tubular reactor. The model was validated by comparing computationally derived RTD curves with experimentally obtained RTD curves, with quantified differences less than 3%. Mixing was quantified using the Tanks-in-Series model. Mixing levels were set by varying flow rate and impeller rpm. Mean age distributions at the outlet, where experimental RTD’s were measured, were very narrow for all levels of mixing studied. RTD’s showed expected characteristics; a wider distribution and long …


Novel Processing Approaches For Thin Film Solar And Related Technologies., Brandon Lavery Aug 2017

Novel Processing Approaches For Thin Film Solar And Related Technologies., Brandon Lavery

Electronic Theses and Dissertations

A growing population along with developing nations are increasing the demand for energy. The International Energy Agency forecasts a global electricity demand increase of 70 percent by 2040. This is an increase from nearly 18 TW to over 30 TW. The sun can be a great clean source of achieving this energy demand. Despite the large solar industry development, the market is still growing as solar energy only accounted for 0.87% of the global energy production in 2013. The opportunity exists to manufacture more affordable solar energy that can penetrate more of the global energy market. In this dissertation, a …


Effect Of High Cationic Flocculant On Anaerobic Digestion Of Municipal Wastewater., Prathap D. John May 2017

Effect Of High Cationic Flocculant On Anaerobic Digestion Of Municipal Wastewater., Prathap D. John

Electronic Theses and Dissertations

Anaerobic digestion (AD) of municipal sludge is a widely used stabilization process at municipal wastewater treatment plants. It is highly effective in reducing sludge volume and produces methane gas which is used as fuel in the wastewater plant. Following digestion sludge is sent to a centrifuge to separate the solids from the liquids. Louisville MSD adds flocculent to material in the centrifuge to better coagulate the solids, thereby aiding in separation of the solids from the liquids. The potential for further AD, COD reduction, and methane generation of the liquid effluent from the centrifuge was unknown, particularly in regards to …


Novel Iii-V Alloys For Unassisted Water Splitting., Alejandro Martinez-Garcia May 2017

Novel Iii-V Alloys For Unassisted Water Splitting., Alejandro Martinez-Garcia

Electronic Theses and Dissertations

Direct conversion of solar energy to fuels by photoelectrochemical (PEC) water splitting has been identified as a promising route for sustainable power generation and storage. However, semiconductor materials with suitable opto-electronic properties have yet to be identified. In this dissertation, band gap engineering of III-V alloys, tuning the light sensitivity of GaP and GaN nitride through alloying Sb, is investigated for developing new semiconductor alloys with appropriate opto-electronic properties and their performance with overall water photoelectrolysis. In addition to III-V materials, copper oxide (Cu2O) electrode was investigated for p-type semiconductor material. The new III-V alloy anodes were studied …


Data Driven Discovery Of Materials Properties., Fadoua Khmaissia May 2017

Data Driven Discovery Of Materials Properties., Fadoua Khmaissia

Electronic Theses and Dissertations

The high pace of nowadays industrial evolution is creating an urgent need to design new cost efficient materials that can satisfy both current and future demands. However, with the increase of structural and functional complexity of materials, the ability to rationally design new materials with a precise set of properties has become increasingly challenging. This basic observation has triggered the idea of applying machine learning techniques in the field, which was further encouraged by the launch of the Materials Genome Initiative (MGI) by the US government since 2011. In this work, we present a novel approach to apply machine learning …


Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde Apr 2017

Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde

Electronic Theses and Dissertations

Biomass processing for industrial products and biofuels has gained an increasing presence as society looks to using sustainable resources for manufacturing and renewable fuels for energy. However, these sustainably produced materials and products cannot gain a competitive edge because of the manufacturing expenses that are a result of high process temperatures and pressures. In order to lower these costs, theoretical modeling has described a value-added co-product strategy as one of the best ways to combat high bioprocessing prices. Biomass has been shown to make effective carbons for energy storage devices such as supercapacitors and batteries. These carbons, with the right …