Digital Commons Network^™

Exploring Energy, Comfort, And Building Health Impacts Of Deep Setback And Normal Occupancy Smart Thermostat Implementation, Zachary Ethan Alderman

Graduate Theses and Dissertations

As smart thermostat adoption rates continue to increase, it becomes worthwhile to explore what unanticipated outcomes may result in their use. Specific attention was paid to smart thermostat impacts to deep setback and normal occupancy states in a variety of conditions while complying with the ventilation and temperature requirements of ASHRAE 90.2-2013. Custom weather models and occupancy schedules were generated to efficiently explore a combination of weather conditions, building constructions, and occupancy states. The custom modeling approach was combined with previous experimental data within the Openstudio graphics interface to the EnergyPlus building modeling engine. Results indicate smart thermostats add the …

On The Fatigue Of Headed Shear Studs In Steel-Concrete Composite Bridge Girders, Brianna Laurene Ovuoba

Graduate Theses and Dissertations

Shear connectors are commonly used in steel bridges to join the concrete deck and steel superstructure, providing a mechanism for shear transfer across the steel-concrete interface. The most common shear connector is the headed shear stud. In the current AASHTO LRFD Bridge Specifications on composite design, shear stud fatigue often governs over static strength, and a large number of shear connectors often result. This dissertation investigates headed shear stud fatigue capacities and demands, and provides insight into conservancies in existing design specifications through examination of existing high-traffic bridge performance.

To investigate stud capacity, a total of six high-cycle fatigue tests …

Investigating Fate Of Silver Nanoparticles In Wastewater Biofilms, Connie Marie Walden

Graduate Theses and Dissertations

As industrial advances make everyday life easier for human kind, the processes by which we need to maintain sanitary conditions for both water and wastewater treatment will become increasingly complex. Innovations in food packaging and textile design incorporate engineered nanoparticles (ENPs) to increase antimicrobial properties of clothing, maintain product color, and keep food in packaging from spoilage. For most products, ENPs released will enter the sanitary sewer system, and ultimately wastewater treatment plants. Biofilms grow universally on surfaces where a protective layer of extracellular polymeric substances (EPS) shields attached cells from stressors. In wastewater treatment, complex biofilms are utilized as …

Cost-Savings Of Implementing Site-Specific Ground Motion Response Analysis In Design Of Mississippi Embayment Bridges, Ethan Ryan Benton Baker

Graduate Theses and Dissertations

Deep dynamic site characterization and a site-specific ground motion response analysis (SSGMRA) were conducted for a bridge site in Monette, Arkansas. The SSGMRA indicated the design acceleration response spectrum determined using the American Association of State Highway and Transportation Officials (AASHTO) general seismic procedure could be reduced by 1/3 for the short period range due to attenuation of the short-period ground motions. The steel girder pile-bent bridge, originally designed using the AASHTO general seismic design procedure, was redesigned using the updated seismic demands estimated from SSGMRA. A cost-savings analysis was then conducted to determine the potential savings associated with conducting …

Development Of An Internal Camera-Based Volume Determination System For Triaxial Testing, Sean Elliott Salazar

Graduate Theses and Dissertations

Accurate measurement of axial, radial, and volumetric strain parameters are critical to the understanding of phase relationships and the constitutive behavior for saturated and unsaturated soils. The use of photographic monitoring techniques for laboratory-based measurement of these parameters have become common. A novel technique that utilized camera instrumentation located within the triaxial testing cell was developed and validated. By placing the instrumentation inside of the cell, instead of the instrumentation being located outside of the cell, the technique eliminated cumbersome corrections required to account for optical distortions due to 1) the refraction of light at the confining fluid-cell wall-atmosphere interfaces, …

Automated Pin-Dot Marking Effects On A709-Gr50 Steel Plate Fatigue Capacity, Michael Andrew Noernberg

Graduate Theses and Dissertations

During fabrication of multi-piece steel bridge assemblies, markings are often made on the steel surface to identify/track individual pieces or to provide reference for fabrication layout or later erection. Automated marking methods such as computer numerically controlled (CNC) pin-dot marking offer fabrication efficiencies; however, for marked steel sections subjected to frequent or repeated loading (i.e. bridge girders) many code specifications require experimental testing to verify any marking effects on fatigue capacity. In this study, the effects of automated pin-dot markings on the fatigue capacity of A709-Gr50 bridge steel are experimentally investigated from 13 specimens considering 2 marking frequencies (corresponding to …

An Evaluation Of Borehole Hydraulic Conductivity Equations And Field Determined Soil Water Characteristic Curves, Johnathan Dale Blanchard

Graduate Theses and Dissertations

The methods utilized to determine the hydraulic conductivity of compacted clay liners (CCLs) are of importance for safe guarding the environment from landfill leachate. Therefore, the methods utilized in the analysis of the Two Stage Borehole (TSB) test, as described in the ASTM D6391-11 (Method A, B, and C) standard, were evaluated. Data from hydraulic conductivity tests, as performed on three test pads, were utilized to review the ASTM D6391-11 equations. Additionally, two test pads were instrumented with volumetric water content and soil water matric potential sensors to facilitate the determination of field-obtained soil water characteristic curves (SWCCs) and hydraulic …

Evaluation Of Water Resources And Hydraulic Influences In The Restoration Of The Western Part Of The Mesopotamian Marshlands, Ali Kareem Al-Quraishi

Graduate Theses and Dissertations

The purpose of this study is to assess the water resources and water conveyance system of the western part of the Mesopotamian marshes (Al-Hammar marsh) as well as develop a water conveyance system to distribute water throughout the western Al-Hammar marsh. These processes are significant to identify the current restoration problems and help to create restoration strategies for the marsh. Also, proper management strategy to the Al-Hammar marsh is necessary to preserve the marsh ecosystem, irrigate lands, and provide domestic necessities in the villages.

The overall project is divided into three main chapters which address the current ecological and hydrological …

Be Here Now, Katrina Luehrmann Rattermann

Graduate Theses and Dissertations

Drawing from my religious upbringing and my identity as a millennial, Be Here Now investigates my personal conflicts with the Art object. The exhibition, comprised of two pink, celebratory installations made-on-site and displayed in adjacent spaces, is an exploration of superficiality. Displayed in spaces that are externally visible from the street, the installations invite audience participation. Through the use of placement, color, construction and material make up, the works provoke visceral reactions from the viewer. Though viewers are able to approach the installations from various vantage points, they are unable to physically enter the works and become immersed within the …

Offside, Maryamsadat Amirvaghefi

Graduate Theses and Dissertations

OFFSIDE highlights the parallels between artists and athletes, as well as the professional communities in which both operate. Through the use of sports related imagery, the artwork explores notions of ethnicity, gender, and politics. While much of the work is autobiographical, OFFSIDE is able to consider the political and personal views surrounding a young Muslim woman while lives with constant uncertainty in the United States and trying to start a career in one of the most competitive cultural fields.

3d Printed Pcu/Uhmwpe Polymeric Blends For Artificial Knee Meniscus, Raissa Araujo Borges

Graduate Theses and Dissertations

3D printing was used to fabricate porous artificial knee meniscus material from biocompatible polymeric blends of polycarbonate-urethane (PCU) and ultra-high-molecular-weight polyethylene (UHMWPE) to enable “weep” lubrication that mimics the native meniscus. 3D printed and molded pure PCU, as well as molded PCU and UHMWPE, were used for comparison. Preliminary printing was done to evaluate the impact of process parameters on the results. The samples were subject to a variety of rotational oscillating friction and wear tests under simulated body fluid and loading conditions to replicate the natural motion of the knee. Results show that 3D printed PCU samples yielded a …

Identifying Genetic Factors Influencing Sperm Mobility Phenotype In Chicken Using Genome Wide Association Studies, Primordial Germ Cell Transplantation, And Rnaseq., Sohita Ojha

Graduate Theses and Dissertations

Sperm mobility is a major determinant of male fertility in chicken. In spite of low heritability of reproductive traits, sperm mobility has high heritability index which suggests presence of quantitative trait loci (QTLs) governing the trait. Our research focused on three objectives: i) to identify the QTLs affecting low mobility phenotype in chicken, ii) to understand the impact of Sertoli-cells and germ cells interactions in influencing the mobility phenotype and iii) to identify the genes and gene networks differentially expressed in male and female PGCs. To detect the QTLs, genome wide association studies (GWAS) was conducted which revealed the presence …

The Economic Benefits Of The South African Agricultural Research Council’S Wheat Breeding Program: 1992–2015, Matthew James Coale

Graduate Theses and Dissertations

Although classified as an upper middle-income country by the World Bank, food insecurity is still a concern throughout South Africa, as was evident in 2014–2015 when a drought left 22% of households food insecure. As such, agricultural research in South Africa is needed specifically in plant breeding to increase yields and help mitigate future food insecurity. To fill this need, the South African government funds the Agricultural Research Council (ARC), which conducts holistic research on wheat and other crops. Wheat is important to South African food security; due to the significant drop in wheat area planted since the abolishment of …

Bank Lending Channel And Changing Credit Standards In The Residential Mortgage Market, Salman Tahsin

Graduate Theses and Dissertations

My dissertation examines the relationship between bank conditions and the residential mortgage market. The first essay investigates the effect of bank distress on the residential mortgage market during the 2007-09 financial crisis. We use the county-aggregated change in the ratio of jumbo to nonjumbo mortgage acceptance rate as an instrumental variable to control for endogeneity between bank distress and county economic conditions. The median decrease in the instrumental variable explains an additional 1.5 percentage point decline in county home prices and a 20 basis point rise in the county unemployment rate, which represent 15% and 5%, respectively, of their median …

Assessing The Current Efficiencies Of Farm Credit Of Western Arkansas, Hailey Paulsen

Agricultural Economics and Agribusiness Undergraduate Honors Theses

Farm Credit is a unique banking structure, as it is a cooperative which pays patronage dividends to its members. As such, the rates for loans (nominal interest rates) that Farm Credit offers can be slightly higher than larger commercial banks because the patronage payment can offset some, all or more of interest rate difference, which results in an effective rate. Farm Credit, like other globally evolving industries, must continuously look for ways to differentiate themselves to compete for new customers and retain existing ones. Thus, this study sets out to survey the members of Western Farm Credit of Arkansas to …

Profitability Analysis Of Varying Herd Sizes Based On Price Signals In Cow-Calf Operations, Colson Tester

Agricultural Economics and Agribusiness Undergraduate Honors Theses

The third most consumed meat around the world is beef. Despite global growth in demand, cattle markets experience price cycles related to biological production lags causing variability in cash flow and profitability for producers. Price-driven herd size management strategies thus have received attention. This study adds to that literature by analyzing both price and production risk using three herd size management strategies: i) steady state – holding herd size constant; ii) dollar cost averaging – keeping reinvestment constant by varying the number of replacement heifers retained at a constant long run average dollar total; and iii) moving average – using …

Shallow Aggregate Ebb-And-Flow System For Greenhouse Lettuce Production, Joseph Chidiac

Graduate Theses and Dissertations

A novel soilless technique for the production of lettuce was developed and evaluated for its viability for ornamental greenhouse growers adapting their ebb-and-flood irrigation benching systems to diversify into growing lettuce, without having to purchase the conventional nutrient film technique (NFT) or deep flow technique (DFT) hydroponic systems. The experimental design was a three by four factorial, with three treatments for aggregate depth (19, 38, and 57 mm) and four treatments for irrigation frequency (once every 1, 2, 4, or 8 hours), for a total of twelve treatment combinations. Each treatment was replicated three times in a randomized complete block …

Modelling The Impact Of National Development Strategies For The East African Rice Sector, Florence Muthee

Graduate Theses and Dissertations

The 2008 food crisis prompted many food importing nations to reconsider the need to be self-sufficient especially in their staple food needs. This awakening led to the launch of the Coalition for Africa Rice Development (CARD) initiative with a goal to double rice production in Africa. Under the CARD umbrella member countries drafted individual National Rice Development Strategies (NRDS). This study is a quantitative assessment of four East African countries’ NRDS: Kenya, Rwanda, Tanzania and Uganda within dynamic global rice economy models. The NRDS targets and strategies are not realistic and included under estimation of rice consumption for Kenya, an …

New Technologies For Evaluating Putting Green Surface Characteristics, Daniel Patrick O'Brien

Graduate Theses and Dissertations

Golf course putting greens require a high level of inputs predicated on timely, well informed decisions. Putting green quality is ultimately defined by performance of the turfgrass, and this performance encompasses both (i) the health and vitality of the turfgrass plants, and (ii) the ability of the turfgrass to exist as a playing surface, as it interacts with the golf ball. For golf course superintendents, accurately and efficiently assessing moisture levels and nutrient status are critical for guiding maintenance practices. This research sought to examine new ways for measuring each of these parameters, and compared them to ground-truth data and/or …

Economic And Policy Evaluations And Impacts Of The National Rice Development Policy Strategies In Malaysia: Self-Sufficiency, International Trade, And Food Security, Roslina Binti Ali

Graduate Theses and Dissertations

Despite the fact that the recent rice policy has been moving to a strategy of self-sufficiency while the status quo of the national rice economy remains ambiguous, Malaysia has made an extreme policy decision to pursue an autarky economy in its rice sector, thus closing borders from the international markets in the future. The goal of this dissertation research is to comprehensively evaluate a deep-rooted rice policy in Malaysia and analyze the holistic impacts of the self-sufficiency and international trade policies at the national and farm-household levels, utilizing economic frameworks. The protectionist policy measures using a Policy Analysis Matrix reveals …

Analyzing The Fundamental Aspects And Developing A Forecasting Model To Enhance The Student Admission And Enrollment System Of Msom Program, Sultanul Nahian Hasnat

Graduate Theses and Dissertations

A forecasting model, associated with predictive analysis, is an elementary requirement for academic leaders to plan course requirements. The M.S. in Operations Management (MSOM) program at the University of Arkansas desires to understand future student enrollment more accurately. The available literature shows that there is an absence of forecasting models based on quantitative, qualitative and predictive analysis. This study develops a combined forecasting model focusing on three admission stages. The research uses simple regression, Delphi analysis, Analysis of Variance (ANOVA), and classification tree system to develop the models. It predicts that 272, 173, and 136 new students will apply, matriculate …

Free-Space Measurements Of Dielectrics And Three-Dimensional Periodic Metamaterials, Clifford E. Kintner

Graduate Theses and Dissertations

This thesis presents the free-space measurements of a periodic metamaterial structure. The metamaterial unit cell consists of two dielectric sheets intersecting at 90 degrees. The dielectric is a polyetherimide-based material 0.001” thick. Each sheet has a copper capacitively-loaded loop (CLL) structure on the front and a cut-wire structure on the back. Foam material is used to support the unit cells. The unit cell repeats 40 times in the x-direction, 58 times in the y-direction and 5 times in the z-direction. The sample measures 12” × 12” × 1” in total. We use a free-space broadband system comprised of a pair …

Our Land Is Not Just Soil: Knowing, Feeling, And Doing Environmental Activism In The Arkansas Ozarks, Ramey Arlen Moore

Graduate Theses and Dissertations

The Ozarks is a holey place, an ancient plateau formed from ancient rocks and the sediment of millions of years of living things. The Ozarks is also, from another perspective a place made from a mesh of overlapping lines, lines of migration, lines of living things, lines of water movement over and through the land. This dissertation engages with the practice of conservation and environmentalism as it is performed and lived by Ozarkers and Arkansawyers, natives and transplants. Based on more than a year of ethnographic fieldwork conducted with the Buffalo River Watershed Alliance, Save the Ozarks, Arkansas Master Naturalists, …

A Portrayal Of An Ottoman City And Its Inhabitants: Administration, Society, And Economy In Ottoman Antakya (Antioch), 1750-1840, Ali Capar

Graduate Theses and Dissertations

This dissertation examines the main features of the social and economic life of the district of Antakya between 1750 and 1840 to essentially understand the characteristics of the daily life of society, administration, political developments, and economic activities in this particular city. While elucidating the city administration, demography, neighborhood life, trade, marketplace, guilds, religious minorities, women, children, and the politics of notables in the district of Antakya between 1750 and 1840; my observations revealed the main aspects of social, economic, and politic life of the city of Antakya- one of the most important religious, political, and commercial centers in the …

Fungi Of Forests: Examining The Diversity Of Root-Associated Fungi And Their Responses To Acid Deposition, Donald Jay Nelsen

Graduate Theses and Dissertations

Global importance of forests is difficult to overestimate, given their role in oxygen production, ecological roles in nutrient cycling and supporting numerous living species, and economic value for industry and as recreational zones. Fitness of the forest-forming trees strongly depends on microbial communities associated with tree roots. In particular, fungi impact tree fitness: mycorrhizal species provide water and nutrients for the trees in exchange for C, endophytic fungi play key roles in host defense against pathogenic organisms, and saprotrophic fungi decompose dead organic matter and facilitate nutrient cycling. In addition, pathogenic fungal species strongly affect forest fitness. Despite their importance, …

Effects Of Pre-Chiller Temperature On The Microbial Ecology Of Whole Bird Carcass Rinses, Rachael Elizabeth Blevins

Graduate Theses and Dissertations

Upon entering a poultry processing facility, birds are already contaminated with a variety of microorganisms. It is the responsibility of the processor to reduce these numbers to deliver a wholesome product to customers. This is not an easy task as there are ample opportunities for further microbial contamination. Some of these opportunities are obvious. For example, any areas where contaminants could be washed off one bird and onto another are always an area for concern, i.e. the scalder or the chiller. There are numerous opportunities for contamination that are not so obvious. These incidents of contamination are not necessarily due …

Experimental Simulation Of A Cross-Flow Rice Dryer, Sangeeta Mukhopadhyay

Graduate Theses and Dissertations

After harvest, rough rice is dried, then dehulled and typically milled before consumption. A broad objective of the “rice drying process”, which comprises drying and tempering, is to maximize the yield of “whole, intact milled kernels”, quantified by the “head rice yield” (HRY). Since rough rice is commonly dried using cross-flow (CF) dryers in the United States of America, the aim of this research was to assess the effect of drying and tempering treatments on milling yields when rice was dried in an experimentally-simulated CF drying column. First, because airflow rate was found to be the least-studied “drying variable”, its …

Population Dynamics Of Ouachita Dusky Salamanders (Desmognathus Brimleyorum) In A Managed Forest Landscape, Kelly Marie Halloran

Graduate Theses and Dissertations

With anthropogenic alteration of landscapes increasing world-wide, managed forests are increasingly important as providers of ecosystem services including habitat for numerous wildlife species. It is crucial to maintain a balance between timber production and conservation of biodiversity on managed landscapes. Salamander populations can play key roles in the function and diversity of temperate forest ecosystems. Several studies have reported negative effects of forestry on terrestrial plethodontid salamanders, but less research has focused on stream-dwelling species, evaluated mechanisms driving observed shifts in abundance, or described the dynamics of populations residing in managed forests. Using a Before-After-Control-Impact design, we examined the effects …

A Study Of The Prevalence Of Gastrointestinal Nematodes In Goats Obtained From Northwest Arkansas, Christine Rose Weingartz

Graduate Theses and Dissertations

Parasitic helminths have always been an issue in small ruminant production; pathogens that pose great negative impact on goat health and productivity. Insufficient work has been done to document the prevalence of parasitic helminths in the United States, especially in the south and southeast, where the largest goat populations are found.

The aim of this study was to survey the prevalence of infections by gastrointestinal nematodes in goats in Northwestern Arkansas. Gastrointestinal tracts were examined from 41 goats of various locations around Northwest Arkansas. Worm species were identified and population burdens were determined. Coprology was correlated with the actual worm …

Agronomic Management Practice Effects On Particulate Organic Matter And Infiltration In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Johan Desrochers

Graduate Theses and Dissertations

Improving the understanding of conventional and alternative management practices and their interactions on aggregate-derived particulate organic matter (POM) fractions and soil hydraulic properties, particularly infiltration, is instrumental to soil and groundwater management and long-term sustainability in the Lower Mississippi River Delta (LMRD) region of eastern Arkansas. The objective of this long-term wheat (Triticum aestivum L.)-soybean (Glycine max [L.] Merr.), double-crop (WSDC) field study in a silt-loam soil (Glossaquic Fraglossudalf) in the LMRD region of eastern Arkansas was to evaluate the effects of conventional and alternative management practices, including wheat-residue level, residue burning, tillage and irrigation, on i) POM fractions and …