Digital Commons Network^™

Study On The Electrochemical Behaviors Of Gc Electrode Modified With Carbon Nanotube-Polyelectrolytes And Its Application For Rutin Detection, Liang Hua, Xia-Qin Wu, Rong Wang

Journal of Electrochemistry

The electrochemical behaviors of rutin and ascorbic acid at single-wall carbon nanotube and polyelectrolytes (dimethyl-diallylammonium chloride, PDDA) film modified glassy carbon electrode was investigated. The cyclic voltammetric results showed that electron transfer of rutin at PDDA/SWCNTs/GC modified electrode is an adsorption-controlled process. The separation of oxidation peak potentials of rutin and ascorbic acid was more than 200 mV. The rutin concentration in the presence of AA were detected by differential pulse voltammetry (DPV). The experimental results indicated that the PDDA/SWCNTs/GC modified electrode can be used for the detection of rutin in the presence of high concentration of AA. The DPV …

Bio-Inspired Design Of Bipolar Plate Flow Fields For Polymer Electrolyte Membrane Fuel Cells, Nannan Guo, Ming-Chuan Leu, Maoliang Wu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The flow field of a bipolar plate distributes hydrogen and oxygen for polymer electrolyte membrane (PEM) fuel cells and removes the produced water from the fuel cells. It greatly influences the performance of fuel cells, especially regarding reduction of mass transport loss. Flow fields with good gas distribution and water removal capabilities reduce the mass transport loss, thus allowing higher power density. Inspired by natural structures such as veins in tree leaves and blood vessels in lungs, which efficiently feed nutrition from one central source to large areas and are capable of removing undesirable by-products, a mathematic model has been …

Influence Of Natural Organic Matter On Plutonium Sorption To Gibbsite, Laura Simpkins

All Theses

Understanding plutonium geochemical behavior is imperative to the development of schemes for remediation of plutonium environmental contamination and accurate assessment of risks posed by the disposal of plutonium bearing wastes. The primary mechanism of plutonium mobility in the environment is subsurface transport. The mobility of plutonium is significantly influenced by redox and complexation reactions. Although the effects of surface mediated redox reactions on plutonium's subsurface mobility have been previously documented, little has been done to determine the impact of organic materials on sorption behavior and oxidation states. To adequately predict the behavior of plutonium in the environment, the influence of …

Determination Of Freshwater Algal Biomass And Sulfolipid Content As Functions Of Inorganic Carbon Treatment, Melissa Morella

All Theses

Cultures of mixed freshwater algae were grown in open batch reactors made up of modified BG-11 media that contained 0, 25, 50 or 100% of the suggested inorganic carbon content (0, 0.5, 0.1 and 0.2 g/L Na₂CO₃) to assess the subsequent production of the high-value product, sulfoquinovosyl diacylglycerol (SQDG). After 25 days of growth, the reactors were composed of primarily Oscillatoria growth. All four reactors exhibited a trend of increasing biomass and alkalinity with time, and an initial increase then decrease in pH. The total inorganic carbon (TIC) in all reactors exhibited a mirrored, opposite trend …

Effect Of Different Oxygen Barrier Pouches On The Quality Of Retorted Carrots, Sarah Khor

All Theses

Thermally processed (TP) baby carrots were packaged in pouches with varying oxygen transmission rate (OTR) pouches. The pouches were four layer laminate (PET-Nylon-Barrier-CPP) with barrier layer being foil, aluminum oxide (AlOx), ethylene vinyl alcohol (EVOH), and nylon. Retort pouches were placed in boxes that were stored in an environmental chamber (43 °C, 50%RH). The objective of the study was to determine an alternative barrier retort pouch that is microwavable and still had similar barrier functions to foil for baby carrots and determine how the alternative compare with regard to shelf life. Instrumental analysis of color (L*, a*, b*) and texture …

The Effect Of Barrier Properties Of Non-Foil Retort Films On Shelf Life Of Oxygen Sensitive Foods, Mahalaxmi Dharman

All Theses

A simulated food product sensitive to oxygen, which was a mixture of tomato paste, water, and corn oil (2:2:1), was filled into five different barrier coated pouches, a foil barrier and a low barrier pouch. These pouches were thermally processed at 250¡F for 30 minutes and stored in darkness under accelerated conditions (45±2¡C and 50±2%RH) for up to 180 days.
The simulant was analyzed for lipid oxidation by TBARS and lycopene degradation by colorimetry (L*,a*,b* values and Hue angle). The oxygen permeability (OP) in all the pouches increased by 5 to 500 fold after retort. TBARS values in all pouches …

Effect Of Processing, Packaging And Vibration Treatment On The Sensory Quality Of Fresh-Cut Apple Slices, M. Siddiq, J. B. Harte, S. P. Singh, A. A. Khan, K. D. Dolan, Koushik Saha

Industrial Technology and Packaging

Fresh-cut fruit industry has seen tremendous growth in recent years. The present study was designed with the objective of studying the sensory quality of fresh-cut apple slices that were treated with different antibrowning agents, packed in three types of packaging materials and subjected to vibration treatment to simulate commercial transportation. The slices were treated with two commercial antibrowning agents [NatureSeal (Mantrose-Haeuser Co., Inc., Westport, CT, USA) and Ever-Fresh (Kraft Foods, Inc., Rye Brook, NY, USA)] at 5% (w/v) application rate. The treated slices were packaged in 5 oz polystyrene rigid container, 2 lb polyethylene bag or 2 oz polyethylene bag. …

Anticipating U.S. Population-Level Health And Economic Impacts Using Discrete-Event Simulation To Guide Health Policy Decisions, Odette Reifsnider

All Dissertations

This dissertation presents two applications of discrete-event simulation (DES) to represent clinical processes: (1) a model to quantify the risk of the maternal obese and diabetic intrauterine environment influence on progression to adult obesity and diabetes, and (2) a model to evaluate health and economic outcomes of different smoking cessation strategies. The first application considers the public health impact of the diabetic and obese intrauterine environment's effect on the prevalence of diabetes and obesity across subsequent generations. We first develop a preliminary DES model to investigate and characterize the epidemiology of diabetes during pregnancy and birth outcomes related to maternal …

Arsenic Accumulation In Rice Grains: Effects Of Cultivars And Water Management Practices, Bin Hua, Wengui Yan, Jianmin Wang, Baolin Deng, John Yang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Arsenic (As) accumulation in rice grains is a threat to human health and marketability of rice products. in an effort to minimize as uptake by rice grains, field experiments were conducted to investigate as accumulation in rice grains of three cultivars in monosodium methane arsonate-treated soil under saturated and flooded water management practices. Results indicated that as concentrations in rice grains were cultivar-dependent and influenced by water management. Soil flooding would substantially enhance the as accumulation with a great variation among cultivars. Extractable as in the soil was positively correlated with sodium dithionite-sodium citrate-sodium bicarbonate solution-extractable Fe, suggesting a strong …

Enhanced Degradation Of Fats, Oils And Greases In Domestic Wastewater Sewer Networks And Grease Interception Systems Using Peat Humic Substances, Matthew Hunnemeder

Theses and Dissertations

The efficacy of peat humic substances in enhancing the degradation of fats, oils and greases (FOG) was investigated under controlled laboratory conditions using bench scale well-mixed bioreactors. An experimental design was used to evaluate the effects of temperature and peat humic substance (PHS) concentration on FOG degradation in domestic wastewater for a temperature range from 10 deg.C to 30 deg.C and a PHS concentration range from 0 to 20 ppm(v). Factors and interactions significantly affecting the rate of FOG degradation were identified, and models to predict FOG degradation rates as a function of PHS concentration and temperature were developed. The …

Spinal Implant With Customized And Non-Linear Stiffness, Eric Ray Dodgen

Theses and Dissertations

There is a need for spinal implants that have nonlinear stiffness to provide stabilization if the spine loses stiffness through injury, degeneration, or surgery. There is also a need for spinal implants to be customizable for individual needs, and to be small enough to be unobtrusive once implanted. Past and ongoing work that defines the effects of degeneration on the torque rotation curve of a functional spinal unit (FSU) were used to produce a spinal implant which could meet these requirements. This thesis proposes contact-aided inserts to be used with the FlexSuRe™ spinal implant to create a nonlinear stiffness. Moreover, …

An Investigation Of Data Protection And Computer Security In Small Irish Medical Practices, Sean Mcgrath

Dissertations

Small medical practices store and process the health information of their patients in order to aid in providing care to them. Because of this a level of trust exists between the patients and the practice to ensure the sensitive medical data is kept private and secure. There was no formalised way to test if this trust was well deserved and what level of protection was applied to such sensitive health records. A security model that is applicable to small medical practices for the purpose of protecting and securing the personal health information they store was constructed and validated by a …

Twin-Screw Extrusion Processing Of Distillers Dried Grains With Solubles (Ddgs)-Based Yellow Perch (Perca Flavescens) Feeds, Ferouz Y. Ayadi, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan, Michael L. Brown

Natural Resource Management Faculty Publications

Increases in global aquaculture production, compounded with limited availabilities of fish meal for fish feed, has created the need for alternative protein sources. Twinscrew extrusion studies were performed to investigate the production of nutritionally balanced feeds for juvenile yellow perch (Perca flavescens). Five isocaloric (~3.06 kcal/g) ingredient blends, adjusted to a target protein content of 36.7% db, were formulated with 0%, 10%, 20%, 30%, and 40% distillers dried grains with solubles (DDGS) at an initial moisture content of 5–7%db, with appropriate amounts of fish meal, fish oil, whole wheat flour, corn gluten meal, and vitamin and mineral premixes. …

Using Modeling And Simulation To Improve Oral Health Services Delivery In Hampton Roads, Virginia, Mohammad J. Alzahrani

Health Services Research Dissertations

The purpose of this study is to examine the system performance in delivering oral health services in a public health district based on the Conceptual Framework to Measure Performance of the Public Health System (PHS). Using modeling and simulation, a predictive model based on the conceptual framework dimensions: mission, structural capacity, processes, and outcomes was developed to predict the performance of public health district in delivering oral health services.

This is a retrospective longitudinal study. The main objective of this study is to use a modeling and simulation approach to predict the performance of public health district dental clinic in …

Use Of Electroluminescent Wire For Monitoring Fatigue In Manual Materials Handling, Spencer Martinez, Chester Matkey

Industrial and Manufacturing Engineering

In the field of manual materials handling, millions of dollars are lost each year in accidents caused by physical fatigue. The purpose of this project is to design a device for monitoring fatigue in manual material handling operations. Combining our knowledge of electronics, new product design, ergonomics, and human factors, we were able to design and test a product to meet these specifications in hopes of developing a prototype for marketability. While we have only developed a prototype, the economic justification is performed for mass production of the product. Using statistics gathered on the percentage of injuries caused each year …

Rem Sleep Alarm, Shaun Kelsey, Brendon Soltis

Electrical Engineering

This paper explores the REM Sleep Alarm project that deals with the sleep cycle of the average human, and how it affects our ability to function when waking up in the morning.

The purpose of this project is to build a device that has the ability to wake a person up when they will feel the most rested. From research done, it appears that most people feel the most rested when woken up during the REM stage of their sleep cycle. Our goal is to have the device detect when the user is in this stage of sleep, determine how …

Unlv Stars Unabridged Report, University Of Nevada, Las Vegas

Reports (USI)

University of Nevada, Las Vegas, by earning a 2011 Silver Rating in the Sustainability Tracking, Assessment & Ratings System (STARS), is ahead of the curve among public universities – and improving.

STARS is a voluntary, self–reporting framework developed by the Association for the Advancement of Sustainability in Higher Education (AASHE) to help measure sustainability performance over time and among colleges and universities nationwide. The UNLV Sustainability Council oversaw STARS, which by measuring sustainability can help UNLV to reduce energy consumption and waste, improve education, attract research, and generate jobs.

A rating of Silver puts UNLV in great company – with …

Value Landscape Engineering: Identifying Costs, Water Use, Labor, And Impacts To Support Landscape Choice., Kelly Kopp, Larry Rupp, Paul G. Johnson, Roger K. Kjelgren, David E. Rosenberg, Heidi Kratsch

CWEL Publications

We present a spreadsheet model that identifies the costs, water, labor, fertilizer, pesticides, fuel, energy, carbon emissions, and particulates required of and generated by a user-specified residential or commercial landscape over its economic life. This life includes site preparation, materials purchase, installation, annual maintenance and replacing landscape features that wear out or die. Users provide a variety of site-descriptive information and the model queries an extensive database of landscape data to calculate costs, required inputs, and impacts. We verified model results against observations of water, labor, fertilizer, and fuel use over eight years at three landscapes in the Salt Lake …

Studying Milk Coagulation Kinetics With Laser Scanning Confocal Microscopy, Image Processing, And Computational Modeling, Richard Joseph Hennessy

Master's Theses

The kinetics of milk coagulation are complex and still not well understood. A deeper understanding of coagulation and the impact of the relevant factors would aid in both cheese manufacturing and also in determining the nutritional benefits of dairy products. A method using confocal microscopy was developed to follow the movement of milk fat globules and the formation of a milk protein network during the enzyme-induced coagulation of milk. Image processing methods were then used to quantify the rate of coagulation. It was found that the texture of the protein network is an indicator of the current status of the …

The Effect Of Dynamic Standing On The Bone Mineral Density Of Non-Ambulatory Children: A Pilot Study, Megan Diane Damcott

Theses

In recent decades, research in osteoporosis has expanded to include the effects of prolonged immobilization on the load-bearing bones of non-ambulatory children. One current therapeutic intervention for this population is a passive standing program, in which the body is fully supported and continuous, stationary loading is applied to the bones, leading to the legs being primarily inactive. This research focused upon the effect of passive standing and a new therapeutic intervention of dynamic standing, a standing therapy in which the body is supported but vertical, reciprocal displacements which mimic the walking gait are applied to the feet, causing the muscles …

Rubisco Recovery From Alfalfa Juice By Ion-Exchange Chromatography In Expanded Bed, S. Kerfai, A. Fernandez, S. Mathe, S. Alfenore

Bioenergy III: Present and New Perspectives on Biorefineries

No abstract provided.

Effects Of Agitational Intensity On Production Of Ethanol Using Thermotolerant Yeast Sachharomyces Cerevisiae In A Digitally Controlled Pilot Scale Bioreactor Of 150 Liters, Farman Ali Shah, Shaheen Aziz, Hafeez Memon, Zeenat Ali, M.I. Rajoka

Bioenergy III: Present and New Perspectives on Biorefineries

No abstract provided.

Identification And Characterization Of Polychlorinated Biphenyl Dechlorinating Microorganisms From Lake Hartwell, Sc, Tess Brothersen

All Dissertations

To date, all attempts to isolate PCB dechlorinators using traditional isolation techniques have failed. In addition, the study of PCB dechlorinating organisms has been hampered because researchers were unable to grow the organisms in sediment-free, defined media. Three microbial species capable of reductive dechlorination of polychlorinated biphenyls have been identified. These three species are from two phylogenetically distinct branches, Dehalococcoides (Bedard et al., 2007) and the DF-1/o-17 group (Wu et al., 2002a; Cutter et al., 2001). The three cultures from which polychlorinated biphenyl dechlorinators have been identified used similar strategies to 'wean' the microbes from the sediments. In this research, …

Protein Structure-Based Method For Identification Of Horizontal Gene Transfer In Bacteria, Swetha Billa

School of Computing: Dissertations, Theses, and Student Research

Horizontal Gene Transfer is defined as the movement of genetic material from one strain of species to another. Bacteria, being an asexual organism were always believed to transfer genes vertically. But recent studies provide evidence that shows bacteria can also transfer genes horizontally.

HGT plays a major role in evolution and medicine. It is the major contributor in bacterial evolution, enabling species to acquire genes to adapt to the new environments. Bacteria are also believed to develop drug resistance to antibiotics through the phenomenon of HGT. Therefore further study of HGT and its implications is necessary to understand the effects …

Decolorization Of An Azo And Anthraquinone Textile Dye By A Mixture Of Living And Non-Living Trametes Versicolor Fungus, Christine M. Dykstra

HIM 1990-2015

Wastewater from the textile industry is difficult to treat effectively due to the prevalent use and wide variety of synthetic dyes that are resistant to conventional treatment methods. White-rot fungi, such as Trametes versicolor, have been found to be effective in decolorizing many of these synthetic dyes and current research is focusing on their application to wastewater treatment. Although numerous studies have been conducted on the ability of both living and nonliving Trametes versicolor to separately decolorize textile dyes, no studies were found to have investigated the use of a mixture of live and dead fungus for decolorization. This study …

Characterization Of Potential Health Promoting Lipids In The Co-Products Of De-Flossed Milkweed, Vicki Schlegel, Richard Zbasnik, Tammy Gries, Bo Hyun Lee, Timothy Carr, Ji-Young Lee, Curtis Weller, Susan Cuppett

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The floss and oil of the common milkweed (Asclepias syriaca L.) seeds are currently used to produce comforters/pillows and skin care products, respectively. As an outcome of these products, copious quantities co-products (pressed seed meal and pod biomass) are disposed of each year despite the presence of potential health benefiting lipids. The objective of this project was to determine the feasibility of developing the lipid fraction from of these co-products for the fast growing dietary human health market. Although certain types of lipids were affected by the extraction solvent used (hexane and diethyl ether) as were overall amounts, analysis …

Migration Models - Comparison Of Pvc, Pet And Pla Diffusivity, Combined With A Production Cost Model For Westridge Laboratories, Shelley Cooke, Sarina Surrette

Materials Engineering

This project has two parts: [1] a migration and diffusivity model for candidate plastics used in containers, and [2] a product cost model for Westridge Laboratories (Santa Ana, CA).

Diffusion modeling is a useful tool to predict migration of polymer constituents into exposed liquids.  Polyvinyl chloride (PVC), polyethylene terephthalate (PET) and polylactic acid (PLA) were studied to estimate production costs, and component migration into water-based liquids from plastic containers.  Bis (2-ethylhexyl) phthalate (DEHP), antimony trioxide, and stannous octoate, are components of concern in the three candidate polymers, respectively.  Normal detection limits for these constituents are about 1 - 10 ppb, …

Investigation Of A Simulated Annealing Cooling Schedule Used To Optimize The Estimation Of The Fiber Diameter Distribution In A Peripheral Nerve Trunk, Arya Vigeh

Master's Theses

In previous studies it was determined that the fiber diameter distribution in a peripheral nerve could be estimated by a simulation technique known as group delay. These results could be further improved using a combinatorial optimization algorithm called simulated annealing. This paper explores the structure and behavior of simulated annealing for the application of optimizing the group delay estimated fiber diameter distribution. Specifically, a set of parameters known as the cooling schedule is investigated to determine its effectiveness in the optimization process.

Simulated annealing is a technique for finding the global minimum (or maximum) of a cost function which may …

Effect Of Heavy Metals Found In Flue Gas On Growth And Lipid Accumulation For Green Algae Scenedesmus Obliquus, Reece Butler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years there has been a growing interest within the United States to replace fossil fuels with biofuels for environmental and national security reasons. Algal feedstocks have the potential of producing significantly higher yields of oil for biofuels than any other source. It is well known that high concentrations of CO₂ can increase algal yields. Flue gas from coal fire power plants is an obvious source of CO₂. The flue gas, however, will contain other chemicals besides CO₂ that may not be beneficial to the algae. The research objectives for this study were to determine …

Algal Biofilm Production And Harvesting System For Wastewater Treatment With Biofuels By-Products, Logan Christenson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Excess nitrogen and phosphorus in discharged wastewaters can lead to downstream eutrophication, ecosystem damage, and impaired water quality that may affect human health. Chemical-based and physical-based technologies are available to remove these nutrients; however, they often consume significant amounts of energy and chemicals, greatly increasing treatment costs. Algae are capable of removing these pollutants through biomass assimilation, and if harvested, can be utilized as a feedstock for biomethane or biodiesel production. Currently, difficulties in harvesting, concentrating, and dewatering algae have limited the development of an economically feasible treatment and production process. When algae are grown as surface-attached biofilms, the biomass …