Physical Sciences and Mathematics Commons^™

Surface Modification Of Pvdf Membranes For Treating Produced Waters By Direct Contact Membrane Distillation, Zahra Anari

Graduate Theses and Dissertations

Direct contact membrane distillation is a promising unit operation for treating hydraulic fracturing flow back and produced water. However, while a hydrophobic membrane is essential to prevent the passage of water from the feed to the permeate side, fouling by dissolved organic species can compromise membrane performance and result in wetting of the membrane pores. Here four monomers, hydroxyethylmethacrylate, acrylic acid, 1-vinyl-3-allylimidazolium bromide, and 1-vinyl-3-hexylimidazolium bromide have been grafted from the surface of a PVDF membrane. The modified and base membranes were tested in a direct contact membrane distillation system. All membranes were challenged with real produced water. In addition, …

Determining Water Requirements In Turfgrass Systems, Tyler Quinn Carr

Graduate Theses and Dissertations

Turfgrass lawns are commonly utilized for home and commercial applications because of the aesthetic, environmental, and recreational benefits grasses provide, but many people perceive turfgrass as solely an aesthetic benefit that requires significant water inputs. It is important to identify and use turfgrass cultivars that have known drought tolerance, and also fine-tune and throughout development. A series of field experiments were conducted to determine the water requirements of turfgrass lawn systems with the following objectives: 1) investigate differences in chronic drought resistance and irrigation recommendations among cultivars of Kentucky bluegrass (Poa pratensis L.) and tall fescue (Festuca arundinacea Schreb.) 2) …

The Cognition Of Controversy: Examining Policy Elites’ Narrative Cognition And Communication Around Hydraulic Fracturing Practices In The U.S., Rachael M. Moyer

Graduate Theses and Dissertations

The use of hydraulic fracturing (HF) technologies to extract oil and gas in the United States has sparked contentious policy debates, producing inconsistent and inefficient policies that have done little to address the impacts of HF in any comprehensive way. Debates are accompanied by competing policy narratives that position HF as either an environmental threat or an economic opportunity, but little is known about how policy narratives around HF are used by individuals. This dissertation systematically examines how individuals cognitively internalize elements of competing HF policy narratives. Organized into three empirical chapters, this dissertation analyzes narrative cognition (Jones, Shanahan, and …

Interpreting Potential Groundwater Policies Through Modeling Of Market And Non-Market Benefits And Costs, Grant H. West

Graduate Theses and Dissertations

Current policies leveraging financial incentives and improved irrigation efficiency to mitigate groundwater scarcity have not proven to curtail trends of resource depletion. Groundwater benefits cannot be appropriately valued solely on market forces, and so deeper policy consideration is warranted under a framework that considers the importance of groundwater across all its values to society. Understanding time preferences for groundwater management and preferences for alternative policies is vital to inform efficient policies. Furthermore, climate change remains politically controversial yet has important consequences for critical groundwater resources and their sustainable long-term management. Proliferating policy narratives concerning climate change could influence the way …

Eastern Collared Lizard (Crotaphytus Collaris) Population Declines In Ozark Landscapes: An Assessment Of Environmental Constraints., Casey L. Brewster

Graduate Theses and Dissertations

The Eastern Collared Lizard (Crotaphytus collaris) has experienced extensive population declines over the past half century in the Ozark Mountains. Previous research suggests that glade habitat degradation through woody vegetation encroachment is an important factor resulting in population declines. In this dissertation I used information on time-energy budgets to investigate the link between habitat degradation and shifts in life history traits likely resulting in population declines of Eastern Collared Lizards (Crotaphytus collaris) in the Ozarks. In chapter one, I addressed the influence of dense woody vegetation encroachment on age-specific growth, body size, body condition and reproduction of C. collaris in …

Mammal Species Inventory Using Various Trapping Methods In Zone 4 Of Billy Barquedier National Park, Belize During Rainy Season, Mersady Redding

Animal Science Undergraduate Honors Theses

Belize is a small country, but it is extremely ecologically diverse. Based on the few studies conducted in Belize, the abundance of mammals is low but diversity is high. Particular findings note the number and identity of species differed between four sites in the Maya Mountains of Belize, indicating that a data set from a single site is not representative of the Neotropical region. Insufficient data is available to estimate current species richness of many areas in Belize, including Billy Barquedier National Park (BBNP). The objective of this study was to explore trapping and documentation methods of terrestrial mammals in …

Strategies To Improve Forage Utilization By Sheep Offered Forage Mixtures, Valens Niyigena

Graduate Theses and Dissertations

In the first experiment, alfalfa and novel endophyte-infected tall fescue (NE+) forages were harvested after a killing frost, then mixed to formulate 4 different treatments; alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. After 3 months of storage as silage, Dorper ewe lambs (n = 20; mean BW = 34.7 ± 6.65 kg) were fed silage for ad libitum consumption, using 5 animals per treatment. Increasing the proportion of NE+ tall fescue improved (P < 0.05) silage total acids and lactic acid concentrations and decreased silage ammonia concentration. Digestible dry matter and organic matter intake and nitrogen utilization parameters decreased with increasing inclusion of NE+ in diet. In the second experiment, 16 Dorper ewe lambs (41.8 ± 4.61 kg BW) were assigned to 4 different treatments; alfalfa silage alone (0 g/kg; CONT) or alfalfa silage mixed with chopped sericea lespedeza (SL) hay to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) on a dry matter basis in a randomized complete block design experiment with 2 period to provide 4 observations per treatment for each experimental period. Increasing the proportion of sericea lespedeza in the diet decreased dry matter and organic matter digestibility but did not affect feed intake. Fecal nitrogen (g/kg N intake) increased linearly (P < 0.01) while urinary N (g/ day and g/ kg of N intake) tended to decreased linearly and quadratically (P ≤ 0.1) with increasing the proportion of SL in diet. In the third experiments, 16 gestating Dorper ewe lambs (49.1 ± 4.61 kg BW) were allocated to 4 treatments; alfalfa silage alone (0% g/kg; CONT) or alfalfa silage mixed with lablab purpureus(LP) hay to provide 90 (LOW), 180 (MED), or 270 g/kg LP (HIGH) on a dry matter (DM) basis, in a randomized complete block design experiment with a total 8 replication per treatment. Supplementation of LP in diet increased quadratically (P ≤ 0.04) forage dry matter, organic matter intake, digestible dry matter and digestible organic matter intake (P < 0.05). Nitrogen apparently absorbed and urinary N both decreased linearly (P < 0.01) with adding more LP hay in diet. Harvesting and mixing alfalfa and fescue after a killing frost improved silage fermentation characteristics and supplementation of tannins from SL and polyphenol from LP altered N excretion.

Key words: lablab, sericea lespedeza, alfalfa silage, nitrogen, sheep.

Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz

Graduate Theses and Dissertations

Soybeans (Glycine max) are one of the major row crops in the United States, particularly in Arkansas. Soybean cyst nematode (SCN, Heterodera glycines) and southern root-knot nematode (RKN, Meloidogyne incognita) are two of the most damaging pests that cause major economic losses in soybeans. Little is known concerning the effects of common and alternative agronomic practices on nematodes in fields with nematode population densities below threshold levels. Therefore, the objective of this study was to evaluate the effects of the combination of tillage (conventional tillage and no-tillage), irrigation (irrigated and non-irrigated), wheat (Triticum aestivum) residue burning (burned and no burned), …

Cost Effectiveness Of Greenhouse Gas Reductions Through Afforestation Of Agricultural Land In The Arkansas Delta, Karli A. Moore

Graduate Theses and Dissertations

Sequestration of atmospheric carbon in forested lands offsets carbon emissions from other industries. Conversion of private lands, particularly agricultural tracts in marginal areas, to forests can bolster carbon abatement. The United States government agencies administer some voluntary, incentive-based programs to encourage landowners to adopt production practices with positive environmental outcomes. This policy stream can be used to increase transition of marginal agricultural land to forests, thereby creating new carbon sinks. We analyze an eleven-county study area in the Arkansas Delta to determine feasibility for a subsidy focused on carbon abatement through afforestation. This study area is significant for two reasons: …

Turbidity And Ion Concentrations Vary With Land Use And Underlying Geology At The West Fork Of The White River, Erin E. Scott, Brian E. Haggard

Technical Reports

The West Fork of the White River (WFWR) watershed in northwest Arkansas is a trans-ecoregion watershed and is experiencing land-use changes, especially in the downstream portion of the watershed. The entire 54-km long river has been on the State’s 303(d) list of impaired waterbodies for turbidity, total dissolved solids (TDS), and sulfate for many years. The purpose of this study was to identify which part(s) of the river fail to meet applicable water quality standards (WQS) and to investigate possible sources of pollutants, whether human-caused or naturally occurring. Water samples were collected once or twice a month at 9 sites …

Stream Water Quality To Support Huc 12 Prioritization In The Lake Wister Watershed, Oklahoma: August 2017 Through May 2019, Bradley J. Austin, Brina A. Smith, Brian E. Haggard

Technical Reports

Nonpoint source pollution associated with human land use (agriculture and urbanization) is one of the leading causes of impairment to waterways in the United States (EPA 2000). The primary pollutants associated with agricultural and urban land use are sediment and nutrients which enter nearby streams during rain events and are then carried downstream. These sediments and nutrients may result in water quality issues in the downstream water bodies like increased algal growth or decreased water clarity (e.g. Smith et al., 1999). Best management practices (BMPs) are often used to mitigate the effects of nonpoint source pollution in the watershed. Practices …

Consumer Preferences For Sustainable Rice Practices In Nigeria, Glory Esohe Okpiaifo

Graduate Theses and Dissertations

Improving the sustainability of rice production is important given its position as a global staple and its environmental footprint. The adoption of sustainable practices can generate positive externalities such as lower environmental pollution and improved working conditions for rice industry workers that could be capitalized via the design of consumer-based marketing strategies. The Sustainable Rice Platform (SRP) initiative aims at advancing the adoption of sustainable practices in rice production. We assess consumers’ perceptions of the SRP sustainability indicators using the Best-Worst Scaling approach to rank SRP sustainability attributes according to their preference shares and examine the effects of demographic characteristics …

Nesting Success Of Dickcissel (Spiza Americana) And Non-Breeding Grassland Bird Use Of Northwest Arkansas’ Remnant And Restored Tallgrass Prairies, Alyssa L. Derubeis

Graduate Theses and Dissertations

Dwindling populations of North American grassland birds are linked to habitat loss. Tallgrass prairie only covers 3% of its pre-settlement-era range. Small-scale restoration projects attempt to increase acreage for prairie avifauna, and while some breeding grassland species are present at these sites, nesting success and non-breeding use are still largely unknown. Both life history aspects are required for effective grassland bird conservation. My first objective was to access nest success of the Dickcissel (Spiza americana) at two remnant and two restored tallgrass prairies in Northwest Arkansas. From May-August 2017 and 2018, I found 114 nests that I monitored to determine …

Impact Of Sanitizers On Salmonella Enterica Contamination And Microbial Populations Of Poultry Processing Reuse Water, Andrew Micciche

Graduate Theses and Dissertations

As human populations increase in numbers, access to clean, fresh water is becoming increasingly difficult to balance between agricultural and municipal demands. Water scarcity is a limiting factor of food production in many countries, whether they are emerging or established economies. In conventional poultry processing systems, access to water is particularly critical for the maintenance and disinfection of processing areas, as well as in processing operations such as scalding, chilling, and carcass washing. The need for sustainable alternatives to single-use water supplies is becoming increasingly more urgent, and as a result, the implementation of water reuse in poultry processing plants …

Stable Isotope And Geochemical Characterization Of Nutrient Sources In The Big Creek Watershed Of Northwest Arkansas, Kelly Robin Sokolosky

Graduate Theses and Dissertations

The establishment of a concentrated animal-feeding operation (CAFO) in Newton County, Arkansas near Big Creek, a tributary of the Buffalo National River, has raised concern over potential degradation of water-quality in the watershed. In this study, isotopic tools were combined with standard geochemical approaches to characterize nutrient sources and dynamics in Big Creek. An isotopic and geochemical reference library of potential nutrient sources in the Big Creek watershed was established by direct sampling of representative potential sources, including septic-system effluent, poultry litter, swine and cattle manure, and CAFO waste lagoons. Representative nutrient sources and Big Creek stream samples were analyzed …

On The Path To A Resilient Urban Food System In A Rural State: A Mixed-Method Needs Assessment Of Urban Producers And County Extension Agents In Arkansas, Catherine Elizabeth Dobbins

Graduate Theses and Dissertations

This project utilized a mixed-method needs assessment approach to urban agriculture in Arkansas, a predominately-rural state. Chapter II was a qualitative study, using semi-structured, in-depth interviews, that investigated the perceptions, needs, and experiences of Arkansas urban farmers and their interactions with the University of Arkansas Division of Agriculture Cooperative Extension Service (CES). Interviews were conducted with 16 urban farmers in Northwest and Central Arkansas. The interview data revealed individualized needs based on the size, years in operation, and mission of each urban farmer interviewed. General needs were determined, such as market pricing, co-ops, and access to appropriate equipment, but generally …

Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use a thermoelectric generator module to analyze the relationship between thermal and electrical energies. Using data collection sensors and analysis software, students will investigate the relationship between the temperature gradient across a thermoelectric generator module and the resulting electrical potential. Students will then use their data and analysis to solve problems relating to waste thermal energy in electrical systems and communicate their work to their peers and teacher.

Producer Preferences For Alternative Irrigation Practices In The Arkansas Delta, Robert Edward Rosene

Graduate Theses and Dissertations

We use a bivariate sample selection model to address peer network effects on participation in and/or intensity of use of land being irrigated by alternative irrigation practices in the state of Arkansas. As groundwater in the state becomes more limited, the use of scientific scheduling, flowmeters, and more efficient row crop water application systems will allow producers to better manage water resources. We find relatively large, positive relationships between belonging to a peer network of the same irrigation practice and participation in that practice. Intensity of use of alternative irrigation techniques is mostly influenced by which crop type the practice …

H2 Control For Improved Stability Of Multi-Area Electric Power System With High Levels Of Inverter-Based Generation, Muthanna Abdulkareem Al-Sarray

Graduate Theses and Dissertations

Increased generation capacity from non-dispatchable energy resources such as wind and solar has created challenges to ensuring the reliable delivery of electric power. This research develops a systematic three-step method of assessing the reliability of electric power systems under a variety of different possible fault conditions to ensure that overall system stability is preserved in a manner the meets regulatory requirements. The first step is a risk-based reliability method (RBRM) that accounts for the probability of a line outage versus the severity of impact. This allows system planners to judiciously allocate expenses for reliability improvements based on the greatest economic …

Analysis And Conservation Of Native Forests At Kessler Mountain Fayetteville, Arkansas, Alan James Edmondson

Graduate Theses and Dissertations

Kessler Mountain in Fayetteville Arkansas has long been recognized for its beauty and natural resources. Parts of Kessler Mountain have been homesteaded and developed in the past, but most of the mountain has remained relatively undisturbed. The planned development of over 4,000 housing units to cover Kessler Mountain stimulated controversy and consideration of other management alternatives. A twist of fate involving an economic recession, a dedicated group of outdoor recreation enthusiasts, and environmental conservationists led to the permanent protection of 384 acres in the Kessler Mountain Regional Park. To help evaluate the natural resources at Kessler Mountain, forest composition, structure, …

Reduced Disposal Area Performance Utilizing Secondary-Treated Effluent In Profile-Limiting Soils, David A. Meints

Graduate Theses and Dissertations

Onsite wastewater systems dispose of primary treated effluent by utilizing the soil for final recycling and renovation of wastewater into the environment. Soil and site limitations have become a challenge to design a wastewater system and dispose of onsite wastewater using a conventional pipe and gravel design. Using secondary-treated effluent from an advanced treatment unit applied to a reduced disposal area offers an additional alternative when developing an onsite wastewater system. The objective of this study was to determine the feasibility of hydraulically loading limiting soils with secondary-treated effluent in a reduced disposal area. A reduced disposal area was constructed …

Evaluating Rice Straw As A Substitute For Barley Straw In Inhibiting Algal Growth In Farm Ponds, Jacob Maris

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Algal blooms disrupt aquatic ecosystems and are more common in lakes, ponds, and rivers during the summer months due to nutrient pollution. Livestock production can contribute increased quantities of nutrients to water bodies from runoff of manure. Commonly used mechanical and chemical control methods may have limited success because algae are small and propagate quickly. Barley (Hordeum vulgare) straw has been shown to inhibit the growth of algae as the straw decomposes aerobically in ponds. Therefore, barley represents a natural option for algal biomass control. However, the small amount of barley production in Arkansas limits the availability of …

Lighting And Economic Considerations For A Hydroponic S-Based Greenhouse At Tri Cycle Farms, Laura Gray

Biological and Agricultural Engineering Undergraduate Honors Theses

Hydroponics is an agricultural technology that involves growing plants without soil, instead using other growth media with added nutrients, typically inside a controlled facility such as a greenhouse. Hydroponics-based agriculture has a number of benefits, namely that it is more water efficient, requires less intensive labor, yields higher quality crops consistently in shorter time, and is easier to control. It also has the potential to be economically advantageous, due to its ability to grow certain crops in the off-season. In Fayetteville, Arkansas, a non-profit urban farm known as Tri Cycle Farms has been seeking a way to design, build, and …

Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare

Biological and Agricultural Engineering Undergraduate Honors Theses

Stream discharge is necessary to estimate loads and calibrate and validate watershed models. Access to long-term water quality data and discharge measurements allows for modeling of water quality changes across a watershed over time. However, discharge monitoring stations are often expensive to install and maintain, particularly in small rivers. A more cost-effective method for monitoring streamflow has been implemented in the Upper Poteau River Watershed (UPRW) in Arkansas. This method consists of an SonTek acoustic doppler instrument for measuring storm stream flow, with is combined with manual baseflow discharge measurements. The combined stormflow and baseflow measurements are combined with a …

Biogeography Of Endemic Dragonflies Of The Ozark-Ouachita Interior Highlands, Wade Alexander Boys

Graduate Theses and Dissertations

A common pattern across many taxonomic groups is that relatively few species are widespread while the majority are restricted in their geographic ranges. Such species distributions are used to inform conservation status, which poses unique challenges for rare or cryptic species. Further, priority status is often designated within geopolitical boundaries, which may include only a portion of a species range. This, coupled with lack of distributional data, has resulted in species being designated as apparently rare throughout some portions of their range, which may not accurately reflect their overall conservation need. The Interior Highlands region of the central United States …

Climate Change Governance And The Politics Of Scale: Evaluating Local Climate Protection Policies And Practices In The United States And Germany, Ayure-Inga Mark Anthony Agana

Graduate Theses and Dissertations

When it became evident that the issue of climate change needed to be acted upon, it was projected as a global scale problem. To make this rhetoric concrete, the international relations logic that ‘regimes’ of cooperating nation-states are the most feasible approach to solving problems that are global in nature was adopted. While the national level has performed poorly in climate change mitigation action, as exemplified by the United States’ refusal to ratify the Kyoto Protocol, Canada’s subsequent withdrawal from the Kyoto Protocol in 2011 after initial ratification and, more recently, the United States withdrawal from the Paris Accord, a …

Amphibian And Reptile Community Responses To Forest And Riparian Disturbance, Jacquelyn Christine Guzy

Graduate Theses and Dissertations

Riparian zones are transitional, semi-terrestrial areas regularly influenced by freshwater. These areas serve as dispersal corridors for many animal and plant species and ultimately function as important reservoirs of biodiversity in altered landscapes. While much of the riparian habitat in the United States has been affected by anthropogenic activities, management actions may mitigate potentially negative influences of these activities. For example, Streamside Management Zones (i.e., riparian buffers; SMZs) are commonly implemented within managed forests to protect water quality, but may also provide habitat for riparian-associated wildlife. Yet, little research has rigorously addressed the value of SMZs for wildlife, particularly cryptic …

The Potential Acidification Of The Mulberry River, Arkansas, Jason Richard Burgess-Conforti

Graduate Theses and Dissertations

The Mulberry River is a 110 km long tributary of the Arkansas River in northwest Arkansas and has been designated as a National Wild and Scenic River since 1992. In 2008, the Mulberry River was added to the 303(d) list of impaired water bodies due to the low pH of a 14.6 km segment of the river which has since increased to 68.7 km. To date, there has been little research performed on the Mulberry River and long-term routinely sampled water quality data is unavailable. The objectives of this dissertation were 1) to evaluate changes in water quality of the …

Landuse And Soil Property Effects On Infiltration And Soil Aggregate Stability In The Lower Mississippi River Valley, Rebecca Lynn Anderson

Graduate Theses and Dissertations

Following European settlement of the Lower Mississippi River Valley (LMRV), agricultural expansion and unsustainable, agriculturally related practices have caused groundwater depletion, soil erosion, and surface water contamination by eroded sediments and sediment-bound nutrients to become major environmental threats to the region. The objective of this study was to evaluate the effects of common landuses [i.e., native prairie, deciduous forest, coniferous forest, Conservation Reserve Program (CRP) grassland, and conventional-tillage (CT) and no-tillage (NT) agriculture] on surface water infiltration and aggregate-stability-related properties [i.e., water-stable macroaggregate (WSA) size distribution, total water-stable macroaggregate (TWSA) concentration, and mean weight diameter (MWD)]. The overall infiltration rate …

Constituent Loads And Trends In The Upper Illinois River Watershed And Upper White River Basin: 2015 October Through 2018 September, Erin E. Scott, Brian E. Haggard

Technical Reports

The Arkansas Natural Resources Commission (ANRC) identified two priority hydrologic unit code (HUC) 8 watersheds, the Upper White River Basin (UWRB; HUC 11010001) and the Upper Illinois River Watershed (UIRW; 11110103), in northwest Arkansas. Nonpoint source (NPS) pollution is a concern in these watersheds, such as excess nutrients from agriculture and sediment from changes in land uses. Several NPS pollution projects have been funded by ANRC, including streambank restoration on Sager Creek and best management practices (BMP) to control urban sediment in Fayetteville. The purpose of this project was to collect water samples at 15 sites in the UWRB and …