Digital Commons Network^™

Statistical Comparisons Of Watershed-Scale Response To Climate Change In Selected Basins Across The United States, John Risley, Hamid Moradkhani, Lauren Hay, Steve Markstrom

Civil and Environmental Engineering Faculty Publications and Presentations

In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual …

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 …

Innovation And Development Of Biofuel Technologies, Nicole Lorenz

Chemical Engineering Undergraduate Honors Theses

The need for viable alternatives to gasoline has lead researchers to explore various options for renewable energy resources. This research study focuses on two major options for renewable energy. The first is biodiesel, which is a fuel that can be made from vegetable oils or animal fats. In this study, biodiesel was made from tall oil, a paper byproduct. A novel reaction method was used, employing high temperature methanol rather than acid or base catalysis. The second option that was investigated is butanol, which is an alcohol with advantages over ethanol. First, a two-step fermentation was examined to improve the …

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 …

Combating Antibiotic Resistance Through Development Of A Novel Antimicrobial Delivery Vehicle, Alex Hatch

Undergraduate Honors Capstone Projects

A thermoreversible gel for antimicrobial agent delivery would provide a novel platform suitable for medical applications from persistent infections arising from localized biofilms. Thermoreversible gels could be used to coat medical implants, to inject for subdermal treatments, or to implement in topical applications. FDA approved Pluronics® form thermoreversible gels and certain Pluronics® display inherent varying degrees of antimicrobial activity. Pluronics® have been shown to affect efflux pumps, and reduce ATP levels within the bacterial cell. In combination with antibiotics and other pharmaceuticals, Pluronics® have been used to sequester drugs and act as a delivery vehicle. With advances in nanomedicine, nanoparticles …

Comparative Studies On Scale-Up Methods Of Single-Use Bioreactors, Emily B. Stoker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was performed to increase knowledge of oxygen mass transfer (kLa) and mixing times in the scale-up of disposable bioreactors.Results of oxygen mass transfer studies showed kLa to increase with increasing agitation and aeration rates. By maintaining a scale-up constant such as gassed power to volume or shear, an almost constant k_La was achieved during scale-up from 50 to 2000 L. Using the scale-up constant P_g/V resulted in statistically higher kLa values at greater reactor volumes. Mixing times were revealed to be significantly affected by agitation, but not by the aeration rates tested. No pattern …

Characterization And Application Of Dynamic In Vitro Models Of Human Airway, Hemangkumar J. Patel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, respiratory diseases have emerged as a leading cause of mortality across the globe. In the United States alone respiratory diseases are the fourth leading cause of deaths annually. Moreover, with the rapid increase of industrialization and urbanization, the occurrences of respiratory diseases are expected to remain high with strong chances of increasing in the future. To ameliorate the epidemic of respiratory disease, it is first important to understand its underlying mechanisms.

Respiratory research studies in animals have elucidated the chronological order of the pathological events and systemic responses inside the lung, but understanding the response of individual …

A Study On The Applications And Toxicity Assessments Of Carbon Nanotubes In Tissue Engineering, Rena Baktur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carbon nanotubes (CNTs) are one of the most popular nanomaterials. There has been increasing interest in the development and applications of carbon nanotubes due to their huge potential in industrial and medical applications. Recent applications of carbon nanotubes include development of scaffolds and drug delivery systems. Despite rapidly emerging applications of CNTs, little is known about the impact of CNTs on cellular processes, especially mesenchymal stem cell (MSC)'s differentiation. Also, the effects of nanoparticle exposure under different conditions on cellular responses have not been well characterized yet.

To characterize the effects of CNTs on creating nanoscale scaffolds for tissue engineering, …

Cellulose Nanocrystals Properties And Applications In Renewable Nanocomposites, Esteban Urena Benavides

All Dissertations

Development of novel bio-based nanocomposites is fundamental to reduce the dependence on fossil resources and provide a sustainable future. In light of this global problem, cellulose nanocrystals (CNCs) have raised interest due to their remarkable mechanical properties. Adequate design of nanocomposites requires a fundamental understanding of how the structure affects the mechanical properties of the material. However, contradictory results in the literature have revealed a lack of comprehension of this relationship for CNC based composites. Consequently, this work provides an explanation to unusual results for CNC nanocomposites presented in the literature and demonstrates the ability to achieve property enhancements in …

Fluid Dynamics Of Cell Printing, Ping He

All Dissertations

Cell printing is an emerging technology that uses droplets to deliver cells to desired positions with resolution potentially comparable to the size of single cells. In particular, ink–jet based cell printing technique has been successfully used to build simple bio–constructs and has shown a promise in building complex bio–structures or even organs. Two important issues in ink–jet based cell printing are the moderate survival rate of delicate cells and the limited cell placement resolution. Resolving these issues is critical for the ink–jet based cell printing techniques to realize their full potential.
In this work, we use numerical simulations to reconstruct …

Comparative Fecal Metagenomics Unveils Unique Functional Capacity Of The Swine Gut, Regina Lamendella, Jorge W. Santo Domingo, Shreya Ghosh, John Martinson, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Background: Uncovering the taxonomic composition and functional capacity within the swine gut microbial consortia is of great importance to animal physiology and health as well as to food and water safety due to the presence of human pathogens in pig feces. Nonetheless, limited information on the functional diversity of the swine gut microbiome is available. Results: Analysis of 637, 722 pyrosequencing reads (130 megabases) generated from Yorkshire pig fecal DNA extracts was performed to help better understand the microbial diversity and largely unknown functional capacity of the swine gut microbiome. Swine fecal metagenomic sequences were annotated using both MG-RAST and …

Salen Mn Complexes Mitigate Radiation Injury In Normal Tissues, Rosalind A. Rosenthal, Brian Fish, Richard P. Hill, Karl D. Huffman, Zelmira Lazarova, Javed Mahmood, Meetha Medhora, Robert C. Molthen, John E. Moulder, Stephen T. Sonis, Philip J. Tofilon, Susan R. Doctrow

Biomedical Engineering Faculty Research and Publications

Salen Mn complexes, including EUK-134, EUK-189 and a newer cyclized analog EUK-207, are synthetic SOD/catalase mimetics that have beneficial effects in many models of oxidative stress. As oxidative stress is implicated in some forms of delayed radiation injury, we are investigating whether these compounds can mitigate injury to normal tissues caused by ionizing radiation. This review describes some of this research, focusing on several tissues of therapeutic interest, namely kidney, lung, skin, and oral mucosa. These studies have demonstrated suppression of delayed radiation injury in animals treated with EUK-189 and/or EUK-207. While an antioxidant mechanism of action is postulated, it …

What Is Inverse-Geometry Ct?, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Inverse-geometry computed tomography (IGCT) systems are being developed to provide improved volumetric imaging. In conventional multislice CT systems, x-rays are emitted from a small area and irradiate a large-area detector. In an IGCT system, x-ray sources are distributed over a large area, with each beam irradiating a small-area detector. Therefore, in the inverse geometry, a series of narrow x-ray beams are switched on and off while the gantry rotates. In conventional CT geometry, cone-beam and scatter artifacts increase with the imaged volume thickness. An inverse geometry may be less susceptible to scatter effects, because only a fraction of the field …

Assessing Phosphorus-Transport From Biosolids Land Application Sites In Utah, Mohan K. Kumar

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Phosphorus Site Index (PSI) is a phosphorus transport assessment tool used to estimate the risk of P transport from soils. Various components, such as soil erosion, P fertilizer application rate, plant available P in soil, etc. that have an influence on P transport from a site, are weighted and given ratings, and a combination of these components are expressed as PSI. This study has considered two biosolids land application sites in Utah, which received biosolids amendments over time, to develop a specialized PSI for the state of Utah.

Phosphorus from land application of biosolids has been considered a potential risk …

Hydrologic Controls On Equilibrium Soil Depths, L. Nicótina, David G. Tarboton, Teklu K. Tesfa, A. Rinaldo

Civil and Environmental Engineering Faculty Publications

This paper deals with modeling the mutual feedbacks between runoff production and geomorphological processes and attributes that lead to patterns of equilibrium soil depth. Our primary goal is an attempt to describe spatial patterns of soil depth resulting from long-term interactions between hydrologic forcings and soil production, erosion, and sediment transport processes under the framework of landscape dynamic equilibrium. Another goal is to set the premises for exploiting the role of soil depths in shaping the hydrologic response of a catchment. The relevance of the study stems from the massive improvement in hydrologic predictions for ungauged basins that would be …

Gpu-Based Global Illumination Using Lightcuts, Tong Zhang

Department of Computer Graphics Technology Degree Theses

Global Illumination aims to generate high quality images. But due to its high
requirements, it is usually quite slow. Research documented in this thesis was
intended to offer a hardware and software combined acceleration solution to
global illumination. The GPU (using CUDA) was the hardware part of the whole
method that applied parallelism to increase performance; the “Lightcuts”
algorithm proposed by Walter (2005) at SIGGRAPH 2005 acted as the software
method. As the results demonstrated in this thesis, this combined method offers
a satisfactory performance boost effect for relatively complex scenes.

Nanocomposite High Displacement Strain Gauges For Use In Human-Machine Interfaces: Applications In Hand Pose Determination, Thomas B. Calkins

Theses and Dissertations

Conductive nanocomposites are finding many uses as multi-functional materials. One recent development involves the creation of high displacement strain gauges, which have potential applications in a variety of engineering roles. The piezoresistive nature of the gauges makes possible their strain sensing capability. The intent of this research is to show that specific High Displacement Strain Gauges can successfully be used in one human-machine interface application that will demonstrate their potential for a range of other human-machine interface applications. This will be shown in the development of these sensors to accomplish hand pose determination. The flexible and inexpensive gauges are attached …

Field Algae Measurements Using Empirical Correlations At Deer Creek Reservoir, Ryan A. Stephens

Theses and Dissertations

Deer Creek Reservoir in Utah has a history of high algae concentrations. Despite recent nutrient reduction efforts, seasonal algae continue to present problems. Cost effective, accurate, and comprehensive monitoring is important to understand the reservoir processes driving this problem and characterizing the algae spatial and temporal distributions are an important part of this effort. Current laboratory methods for accurately measuring algae are expensive and time consuming and are based on water samples taken in the field and transported to the laboratory. This approach only provides data for relatively few point samples because of the time and expense of sample collection …

Construction And Use Of A Direct Calorimeter To Estimate Energy Expenditure In Hibernators, Mark S. Burger, Frank Van Breukelen

Festival of Communities: UG Symposium (Posters)

Metabolic rates have traditionally been estimated through indirect calorimetry (gas exchange or respirometry) due to its ease and availability. Oxygen consumption neglects the contributions of anaerobic metabolism, while direct calorimetry (heat production) estimates both anaerobic and aerobic metabolism. Walsberg and Hoffman (2005) report anaerobic metabolism may be more important to small rodents than was previously thought. During the non-steady state of mammalian hibernation, we hypothesize that anaerobic processes may play an even greater role in fueling metabolism. To address this question, we constructed a very sensitive calorimeter that utilizes the Seebeck effect from a thermoelectric element (Peltier device). We describe …

Event Program, Carl Reiber, Nicholle Booker

Festival of Communities: UG Symposium (Posters)

UNLV Undergraduates from all departments, programs and colleges participated in a campus-wide symposium on April 16, 2011. Undergraduate posters from all disciplines and also oral presentations of research activities, readings and other creative endeavors were exhibited throughout the festival.

Dual-Channel Imaging System For Singlet Oxygen And Photosensitizer For Pdt, Seonkyung Lee, Martin E. Isabelle, Kristin L. Gabally-Kinney, Brian W. Pogue, Steven J. Davis

Dartmouth Scholarship

A two-channel optical system has been developed to provide spatially resolved simultaneous imaging of singlet molecular oxygen (¹O₂) phosphorescence and photosensitizer (PS) fluorescence produced by the photodynamic process. The current imaging system uses a spectral discrimination method to differentiate the weak ¹O₂ phosphorescence that peaks near 1.27 μ m from PS fluorescence that also occurs in this spectral region. The detection limit of ¹O₂ emission was determined at a concentration of 500 nM benzoporphyrin derivative monoacid (BPD) in tissue-like phantoms, and these signals observed were proportional to the PS fluorescence. Preliminary in …

Biodeterioration Of Coastal Concrete Structures By Macro Algae - Ulva Fasciata, Stri Hari Babu Jayakumar, Rama Saravanane, Thirumalai Sundararajan

Journal of Marine Science and Technology–Taiwan

Puducherry is a coastal region in India where the growth of Ulva fasciata (Delile) is very abundant on all marine structures. Though the detrimental effect of this macro algae U. fasciata is a secondary one, its effect has to be investigated. To know its effect, the basic mechanism by which U. fasciata deteriorates concrete structures has been highlighted. To ascertain its detrimental effect on coastal concrete structures, M20 grade concrete cubes were casted and immersed in the coastal area where there is abundant growth of U. fasciata. In addition laboratory simulation has been carried out. Concrete samples collected from the …

Gas Embolic Factors In Cardiovascular Health, Eric L. Cutler

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Gas emboli are a clinical issue often encountered in the space exploration, marine construction, and medical fields.  Individuals involved with these disciplines will often have asympomatic gas emboli circulating throughout their bodies on a regular basis.  A study into the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis in humans is thus presented.  This research utilized a custom built cardiovascular flow simulator and accompanying data acquisition system to experimentally determine the influence of gas emboli under varied circumstances on the mean wall shear stress of a tube in-vitro.  A directly inverse relationship between gas embolus presence in …

Quantitative Reappraisal Of The Helmholtz-Guyton Resonance Theory Of Frequency Tuning In The Cochlea, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

To explore the fundamental biomechanics of sound frequency transduction in the cochlea, a two-dimensional analytical model of the basilar membrane was constructed from first principles. Quantitative analysis showed that axial forces along the membrane are negligible, condensing the problem to a set of ordered one-dimensional models in the radial dimension, for which all parameters can be specified from experimental data. Solutions of the radial models for asymmetrical boundary conditions produce realistic deformation patterns. The resulting second-order differential equations, based on the original concepts of Helmholtz and Guyton, and including viscoelastic restoring forces, predict a frequency map and amplitudes of deflections …

Manipulating Cellular Growth Responses To Patterning, Apoptotic, And Environmental Cues, James N. Mcnamara

Doctoral Dissertations

In this work, various methods of controlling cell growth are examined. Cell-cell interaction, apoptotic cues, three dimensional scaffolds, and non-adherent environments are evaluated for their ability to affect the differentiation, morphology, and growth rate of different cell types. Previous work has shown that cell growth and cell morphology can be influenced by patterns of polymers coated on surfaces in two dimensions, designated here as the x and y dimensions of a standard Cartesian coordinate system. Tissue engineering and regenerative medicine studies have shown limited success in modifying growth in the third, z dimension. This work considers not only the x, …

Ultrasonic Assisted Layer-By-Layer Assembly For Stable Nanocolloids Of Curcumin And Paclitaxel, Zhiguo Zheng

Doctoral Dissertations

Researchers have been trying to fight cancer with synthesis of new bioactive compounds but many of these novel drugs have low solubility in water and it is difficult to deliver them into a patient's body. One way of solving this particular problem is to use nanoscale drug delivery systems. In this dissertation, we describe using an ultrasonic assisted layer-by-layer encapsulation process to prepare anti-cancer drugs with 50∼200 nm particle size with designed coating to achieve sustained release and target delivery.

Two methods for systematic manufacture of low solubility anti-cancer drug nanoparticles were proposed: I) Top-down approach to breakdown larger drug …

The Effect Of Maternal Diet On Fetal Development, Catherine Wilcox

Renée Crown University Honors Thesis Projects - All

Using mice as a model system, this study aimed to compare the effect of a high fat diet (HFD), high sugar diet (HSD) and a control diet (CD) on fetal growth and development at the time of birth (post-natal day 0 or PND 0), post-natal day 7 (PND 7) and post-natal day 14 (PND 14). Published literature has documented the effects of a negative in-utero environment on fetal development, but currently there is limited research regarding the continued effects on development after birth. Mouse pups were harvested and then imaged in 3-D using a high-resolution micro-computed tomography (micro-CT) system. Total …

Do Invasive Riparian Woody Plants Affect Hydrology And Ecosystem Processes?, Julie Huddle, Tala Awada, Derrel Martin, Xinhua Zhou, Sue Ellen Pegg, Scott Josiah

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

© 2011 Copyright by the Center for Greot Plains Studies, University of Nebraska-Lincoln

The Solvent Effectiveness On Extraction Process Of Seaweed Pigment, Warkoyo Warkoyo, Elfi Anis Saati

Makara Journal of Technology

Eucheuma cottonii seaweed is a species of seaweed cultured in Indonesian waters, because its cultivation is relatively easy and inexpensive. It has a wide variety of colors from green to yellow green, gray, red and brown, indicating photosynthetic pigments, such as chlorophyll and carotenoids. An important factor in the effectiveness of pigment extraction is the choice of solvent. The correct type of solvent in the extraction method of specific natural materials is important so that a pigment with optimum quality that is also benefical to the society can be produced. The target of this research is to obtain a high …

Guidance, Navigation And Control Of A Fly-By-Wire Transport Category Airship Designed For Hover Cargo Delivery, Harshad H. Lalan

Master's Theses - Daytona Beach

The purpose of this thesis is to develop fly-by-wire pilot controls for a transport category airship propelled with six thrust vectoring engines, and to develop control laws to maintain position, heading, and attitude during hover and cargo operations. Owing to the large body area, most airships require that they be pointed into the wind to maintain their position. This research aims at controlling an airship attitude and position during hover cargo delivery, irrespective of the wind direction.

Control laws were developed for two primary modes of the airship: Flight (High Speed Mode) and Hover (Cargo Delivery Mode). Different sets of …