Engineering Commons^™

Design, Fabrication, And Measurement Of A Multiple-Input Multiple-Output (Mimo) Antenna For Mobile Communication, Christopher Charles Arnold

Graduate Theses and Dissertations

This thesis presents the design, fabrication and characterization of a multiband uniplanar MIMO antenna for hand-held mobile communication devices on LTE, WLAN, and WMAN networks. The antenna design methodology combined a variety of broadbanding techniques that resulted in a single-layer hybrid monopole antenna coupled to a meander line element and parasitic structures. The 115×55×1.54 mm antenna was fabricated using an FR4 composite material and occupies only a fractional volume within the size of an average cellular phone allowing ample space to integrate with existing hardware. Characterization of the MIMO antenna included input impedance, scattering parameters and radiation pattern cross sections …

Multiplexed Microfluidic Loop-Mediated Isothermal Amplification Of The 16s Rrna Gene For The Diagnosis Of Neonatal Sepsis In Resource-Limited Environments, Griffin Thomas Sonaty

Biomedical Engineering Undergraduate Honors Theses

Bacterial infection, or sepsis, places a disproportionately high burden on newborns in developing countries. This is due in part to a lack of diagnostic tools suitable for sustainable use in resource-limited nurseries. One potential vehicle for a new diagnostic assay is loop-mediated isothermal amplification (LAMP), a high-yield DNA amplification method. LAMP has been used to detect single genes from bacteria in blood serum samples to aid in sepsis diagnosis. While specific, this approach can only provide detection for one species at a time. LAMP could be adapted to detect a broader set of bacteria, while retaining a degree of specificity …

Effect Of Sodium Acetate On Butanol Production By Clostridium Saccharoperbutylacetonicum Via Abe Fermentation, Brigetta Super

Chemical Engineering Undergraduate Honors Theses

Clostridium saccharoperbutylacetonicum is used in ABE fermentation which historically produces a solvent mixture of 3:6:1 parts acetone, butanol, and ethanol respectively. The fermentation process undergoes two phases, an acidogenesis phase which produces butyric acid, and a solventogenic phase which reutilizes the butyric acid, making butanol. For ABE fermentation to compete economically with butanol production from petroleum, the concentration of butanol in the solvent product must be increased dramatically. Unpublished research by Carver student Kayla Kimbrough in the summer of 2012 showed that the addition of salts (sodium acetate) to PYG fermentation media increased butanol production from Clostridium saccharoperbutylacetonicum significantly. When …

Electrocoagulation For Sulfate Removal, Michael A. Layton

Chemical Engineering Undergraduate Honors Theses

In the United States, one of the major rising issues is water shortage, especially in Western, inland states with arid climates. Not only do deficiencies exist for potable water, but for irrigation and agricultural purposes as well. Currently, the Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico has four separate wells that are being used for experimentation. A major concern is that a considerable amount of this water is currently wasted by being sent to evaporation ponds without any sort of treatment for human consumption. The WERC-A-HOLICS have identified two possible methods to alleviate this problem. Electrocoagulation (EC) …

Electrocoagulation For Sulfate Removal, Hailey Marie Dunsworth

Chemical Engineering Undergraduate Honors Theses

In the United States, one of the major rising issues is water shortage, especially in Western, inland states with arid climates. Not only do deficiencies exist for potable water, but for irrigation and agricultural purposes as well. Currently, the Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico has four separate wells that are being used for experimentation. A major concern is that a considerable amount of this water can be used as another reliable source for potable water if treated. The WERC-A-HOLICS have identified two possible methods to alleviate this problem. Electrocoagulation (EC) is a technology useful for …

Electrocoagulation For Sulfate Removal, Gina Marie Densmore

Chemical Engineering Undergraduate Honors Theses

In the United States, one of the major rising issues is water shortage, especially in Western, inland states with arid climates. Not only do deficiencies exist for potable water, but for irrigation and agricultural purposes as well. Currently, the Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico has four separate wells that are being used for experimentation. A major concern is that a considerable amount of this water is currently wasted by being sent to evaporation ponds without any sort of treatment for human consumption. The WERC-A-HOLICS have identified two possible methods to alleviate this problem. Electrocoagulation (EC) …

Using The Triple Bottom Line To Select Sustainable Suppliers For A Major Oil And Gas Company, Pandarinath Adarsh Sunkari

Graduate Theses and Dissertations

Companies have primarily been focusing on the financial bottom line i.e., on increasing profits by increasing revenues and reducing costs. With high energy usage and environmental change posing threats to the environment and business operations, companies are now considering sustainability. Since some global suppliers have low cost labor, Social well-being and human development has also emerged as major goals of a company performing global operations. Focusing on these three goals is termed the "Triple Bottom Line" (TBL). We study and explore the TBL benefits that could be realized by an oil and gas company by focusing on sustainable suppliers. A …

Novel Separation Methods Using Electrodialysis/Electrodeionization For Product Recovery And Power Generation, Alexander Miguel Lopez-Rosa

Graduate Theses and Dissertations

The use of electrodialytic separations for the purification of products has been a vital technique for the past 50 years in the chemical industry. Originally used for demineralization and desalination, electrodialysis and its counterparts have expanded to assist in product purification, waste and hazard removal, and power generation. This research focused on the development of high purity organic acids purification with low power requirements. Work resulted in the development of a new type of electrodialysis process, specifically the use of ionic liquids as a secondary solvent for the development of dual solvent electrodialysis. Through dual solvent electrodialysis, ions were recovered …

Multiplexed Loop-Mediated Isothermal Amplification Of The 16s Rrna Gene For The Diagnosis Of Neonatal Sepsis In Resource-Limited Environments, Griffin T. Sonaty

Inquiry: The University of Arkansas Undergraduate Research Journal

Sepsis, or dysregulated inflammation caused by bacterial infection, places a disproportionately high burden on newborns in developing countries. This is due in part to a lack of diagnostic tools suitable for sustainable use in resource-limited nurseries. One potential vehicle for a new diagnostic assay is loop-mediated isothermal amplification (LAMP), a high-yield DNA amplification method. LAMP has previously been used to detect genes from single species of bacteria in blood serum samples to aid in sepsis diagnosis. LAMP could be adapted to detect a broad set of bacteria, while retaining a degree of specificity that allows clinicians to begin directed antimicrobial …

Development Of A Heart Rate Variability Measurement System Using Embedded Electronics, Naresh Kumar Velmurugan

Graduate Theses and Dissertations

Recent advances in embedded electronics have a remarkable influence on the health care system. One of the most important applications is to monitor the health care of the patients at anytime and anyplace. In the last two decades, many researchers have focused mainly on heart rate variability (HRV) measurements. Patient's heart rate variability should be continuously monitored to help them in case of emergency. Under these circumstances, patients are required to have a HRV measuring kit for a constant observation.

The proposed project focuses on the development of a heart rate variability measurement system with the use of embedded electronics. …

Integration Of Energy Storage Into A Future Energy System With A High Penetration Of Distributed Photovoltaic Generation, Arthur K. Barnes

Graduate Theses and Dissertations

Energy storage units (ESU) are increasingly used in electrical distribution systems because they can perform many functions compared with traditional equipment. These include peak shaving, voltage regulation, frequency regulation, provision of spinning reserve, and aiding integration of renewable generation by mitigating the effects of intermittency.

As is the case with other equipment on electric distribution systems, it is necessary to follow appropriate methodologies in order to ensure that ESU are installed in a cost-effective manner and their benefits are realized. However, the necessary methodologies for integration of ESU have not kept pace with developments in both ESU and distribution systems. …

Durability Of Silane Sealer In A Highly Alkaline Environment, Cameron David Murray

Graduate Theses and Dissertations

Alkali-silica reaction (ASR) is a chemical reaction between siliceous minerals present in certain aggregates and alkalis in the concrete pore solution. The reaction can lead to expansion and severe damage in concrete members. One method to mitigate ASR expansion is to use a penetrating sealer such as silane. A set of columns located in a food preparation facility was treated with silane and a complimentary laboratory study was performed. A cleaning regimen involving application of an alkaline cleaner is employed at the facility, followed by rinsing with hot, pressurized water. The purpose of this research is to evaluate the effectiveness …

A Swat Model For A Cocoa Growing Region In Ghana, Russell Thomas Bair

Biological and Agricultural Engineering Undergraduate Honors Theses

For agricultural outputs to rise with population, more sustainable and productive methods must be identified. Watershed modeling is a way to relatively quickly compare possible impacts of large scale agricultural practice changes. The goal of this project was to develop a watershed model for the Pra River basin in southern Ghana, a cocoa growing region, that could be used for future impact studies of land management practice options. The model was developed using the Soil Water Assessment Tool (SWAT) and calibrated using the best daily stream flow data that could be readily located. With an R2 value of 0.57 and …

Coal Fires: An Environmental Disaster, Edward K. Jenner

Chemical Engineering Undergraduate Honors Theses

Coal Fires are an environmental disaster.

Water System For Developing Countries / Disaster Relief Made With Local Materials, Dong Joon Lee

Chemical Engineering Undergraduate Honors Theses

As the equipment builder of the team, I was responsible for building the treadle pump, the sand filter tank, the hand pump, and generating the instructions for each equipment. Each team member was responsible for certain parts of the water purification system, but everyone worked cohesively on all parts of the design when assistance was necessary. The original design for the treadle pump was a two-man powered pump which discharged water at 15 gallons per minute. Since our system only required less than half of the flow rate, and required another person to operate the bicycle, the pump was redesigned …

Understanding The Influence Of Interfacial Chemistry In Core, Core/Shell And Core/Shell/Shell Quantum Dots On Their Fluorescence Properties, Omondi Bernard Omogo

Graduate Theses and Dissertations

Colloidal semiconductor nanocrystals (quantum dots) have received a great deal of attention due to their superior size tunable properties and promising applications in many areas. Some of the most practical areas of their applications include light emitting diodes (LED), photovoltaic and biological studies. Synthetic methods of these crystals is becoming more established with new strategies being reported every now and then. However, quantitative studies connecting the processes at the interface, namely core-ligand, core-shell and shell-shells, to the overall quantum dots fluorescence properties are not well understood. Specifically for cores, relating surface-atoms interactions, solvents, ligands nature, density and functional groups on …

Return To Traffic Of Full Depth Reclamation Pavements, Robert Benjamin Hill

Graduate Theses and Dissertations

Full-Depth Reclamation (FDR) is a cost-effective rehabilitation treatment for deteriorated pavements. However, when using asphalt emulsion based rehabilitation techniques one of the most challenging aspects of FDR is determining when traffic can be returned to the rehabilitated pavement surface. Since asphalt emulsion mixtures need ample time for curing, they cannot be sealed with a surface layer until the water has evaporated from the rehabilitated layer. It is often not possible to keep the road closed until all of the water has evaporated and the surface layer is placed, therefore, at some point the traffic needs to be returned to the …

Full Depth Reclamation: Bringing Developing Countries' Transportation Up To Speed, Sadie Smith

Civil Engineering Undergraduate Honors Theses

Often, a direct correlation is observed between a country’s transportation network and economic development. Evidence of this is observed all over the world. Full Depth Reclamation (FDR) is a roadway recycling technique that mills and mixes the existing roadway with a stabilizing agent and then re-compacts the mixture to create a thicker, stabilized pavement layer. This method is both cost effective and environmentally friendly, making it a very appealing option as the need to rehabilitate or increase the structural capacity of existing roads grows. In this study, the material characterization of FDR was examined as a composite material of both …

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …

Full Depth Reclamation: Compaction And Moisture Content, Alexander Jackson

Civil Engineering Undergraduate Honors Theses

Many times a road will fail and will be in need of both a structural increase and a repair. Full Depth Reclamation (FDR) is a road rehabilitation technique able to offer both. This method also has a lower total cost and significantly lower material usage than traditional overlaying repair methods. FDR is a road repair method which mills up the current road down into the subgrade, and then stabilizes and compacts the milled material. This is also useful for correcting deeper problems in the road structure which are not addressed by traditional methods. In this study, three different suggestions of …

Evaluating Arkansas Roadway Intersection Accidents Using Traffic Safety Analysis Methods: Generalized Estimating Equations And Roadway Observation, Jacob Mercer

Industrial Engineering Undergraduate Honors Theses

Considerable research has been made in recent years to evaluate road traffic safety. This is especially true with the United States, whose international rank in public safety is rapidly declining. In 2004, Arkansas ranked as the third highest in traffic fatalities among all the states. These are striking numbers that reflect the lack of attention that the state has received in terms of evaluating road traffic safety. Historically, this safety is measure by one of two methods: Statistical analyses of historical data or hands-on, observational analyses of present safety conditions. Rarely in research are both methods used within the same …

Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J.F. Alvarez Barreto

Inquiry: The University of Arkansas Undergraduate Research Journal

High value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs often occur. When compared to traditional solvents, water can be viewed as an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50'C, 70'C, 85'C and 100'C water as a function of time. For taxifolin, silychristin, …

Proceedings Of The Arkansas Academy Of Science - Volume 24 1970, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.