Physical Sciences and Mathematics Commons^™

An Experimental And Computational Evaluation Of The Importance Of Molecular Diffusion In Gas Gravity Currents, Jeremy Jac Herman

Graduate Theses and Dissertations

The accidental release of hazardous, denser-than-air gases during their transport or manufacture is a vital area of study for process safety researchers. This project examines the importance of molecular diffusion on the developing concentration field of a gas gravity current released into a calm environment. Questions which arose from the unexpectedly severe explosion in 2005 at Buncefield, England were of particular interest. The accidental overfilling of a large tank with gasoline on a completely calm morning led to a massive open air explosion. Forensic evidence showed that at the time of ignition, a vapor cloud, most of which now appears …

Attitudes And Behaviors In Online Communities: Empirical Studies Of The Effects Of Social, Community, And Individual Characteristics, Richard Kumi

Graduate Theses and Dissertations

Online communities and communities of practice bring people together to promote and support shared goals and exchange information. Personal interactions are important to many of these communities and one of the important outcomes of personal interactions in online communities and communities of practice is user-generated content. The three essays in the current study examines behavior motivation in online communities and communities of practice to understand how Social and personal psychological factors, and user-generated influence attitudes, intentions and behaviors in online communities.

The first essay addresses two research questions. First, how does Social capital influence exchange and combination behaviors in online …

Bedrock Geological Map Of The Rockhouse Quadrangle, Carroll And Madison Counties, Arkansas, Douglas Eben Jones

Graduate Theses and Dissertations

A digital geologic map of the Rockhouse quadrangle, Carroll and Madison counties, Arkansas, was created on a 1:24,000 scale using ArcMap 10 and Photoshop CS4. The data obtained in the field are digitized onto the United States Geological Survey (USGS) digital raster graphic (DRG) of the Rockhouse quadrangle. The geology in the Rockhouse quadrangle consist entirely of sedimentary rocks that are Paleozoic ranging from Lower Ordovician to Mississippian in age. The Ordovician System is represented by the Cotter, Powell, Everton, and St. Peter Formations. The Cotter and Powell are the prominent bluff forming units throughout the quadrangle and along the …

Evaluation Of Broiler Litter Heat Production During Windrowing & Nitrogen Based Gas Emission Mitigation Using Biofilter, Min Lei

Graduate Theses and Dissertations

Ammonia emission from animal feeding operations (AFOs) has negative effects on environment and animals' health. Thus measuring and mitigating ammonia emission from AFOs is important for environmental protection. In chapter I, different ammonia measurements were discussed and a mitigation technology- biofilter was represented.

In-house windrowing of built-up litter has been used by broiler producers to reduce pathogen loads and rejuvenate litter for the next flock. When litter is piled up for an extended period during downtime, heat generated by the litter pile can become a substantial heat source due to the metabolism of microorganisms. In chapter II, heat production rates …

Evaluation Of Water Sanitation Options For Poultry Production, Pramir Maharjan

Graduate Theses and Dissertations

An evaluation of poultry farm water supplies was conducted to determine the value and impact of water system sanitation practices in commercial broiler houses on microbial levels. Water line cleaning between flocks using concentrated disinfectant solution before placing chicks reduced biofilms retained in the lines to a safe level. Occasional microbial surges were noticed during different points of flock grow-out period even when daily water sanitation was present indicating water is highly susceptible to microbial contamination. However, the daily water sanitation practice controlled the occasional microbial surges in water from sustaining and kept drinking water to a microbiologically acceptable level. …

A Geomechanical Study Of The Mississippian Boone Formation, Karen Nicole Mason Buckland

Graduate Theses and Dissertations

The Boone Formation in northwest Arkansas is a chert-limestone sequence analogous to the subsurface Mississippi Lime reservoir in parts of Oklahoma and Kansas. It has low permeability and produces via horizontal drilling and hydraulic fracturing. The response to stimulation by fracturing is dependent on the quantity of chert in the area. Chert nodules and laterally extensive chert layers in the sequence are variable. Locally, cm- to dm-scale chert bedding is continuous and comprises up to 50% of the outcrop. Elsewhere, the chert is nodular and intermittent.

Samples collected from representative outcrops spanning the thickness and aerial extent of the formation …

Student Motivation For Pursuing A Minor In Environmental Sustainability, Luanne Woods Lewis

Graduate Theses and Dissertations

Environmental sustainability dominates the global conversation seeking to increase awareness and change the culture of thinking concerning the relationship between humans and the Earth. Because many universities offer programs relative to environmental sustainability, a need exists to understand why students pursue these programs. This study examined student motivation for pursuing an environmental sustainability minor in one institution of higher education. Career, learning, monetary, and Social responsibility were the motivational factors considered in this study. The results of this study indicated significant differences among the motivational factors for pursuing a minor in sustainability among those students surveyed. Significant differences existed for …

Agricultural Production And Stability Of Settlement Systems In Upper Mesopotamia During The Early Bronze Age (Third Millennium Bce), Tuna Kalayci

Graduate Theses and Dissertations

This study investigates the relationship between rainfall variation and rain-fed agricultural production in Upper Mesopotamia with a specific focus on Early Bronze Age urban settlements. In return, the variation in production is used to explore stability of urban settlement systems. The organization of the flow of agricultural goods is the key to sustaining the total settlement system.

The vulnerability of a settlement system increases due to the increased demand for more output from agricultural lands. This demand is the key for the success of urbanization project. However, without estimating how many foodstuffs were available at the end of a production …

The Consciousness Of Water: Narrative Flows, Environmental Change, And The Voice Of Yemen, Tricia Nellessen

Graduate Theses and Dissertations

Icebergs are melting in the Arctic. The Gulf of Mexico is warming and producing hurricanes such as Katrina. The delta of the southern United States is drying. And, Yemen will be the first country in modern history to experience a lack of accessible ground water, as soon as 2017 possibly. Yemen's situation has been tracked by scholars and governments since the 1960s. Despite this fact, cities have expanded in Yemen and the population has increased its use of water while little has been invested in desalination or infrastructure to offset growth. Climate change has affected humans for thousands of years; …

Cost-Benefit Analysis Of Farmer Training In Ghanaian Cocoa Farming, Michael Norton

Agricultural Economics and Agribusiness Undergraduate Honors Theses

While billions of dollars flow into low-income countries each year to help alleviate poverty, assessing the effectiveness of these dollars is a challenging task. The literature is rich in studies that measure the benefits of rural development programs. However, many of these studies lack a temporal dimension because they measure cost and benefits for only capital investments and for only a single, static year, while not accounting for skill enhancement. By only measuring net producer benefits during the life of the development program, the cost-benefit analyses (CBA) may not truly capture the full net benefits of a given program. In …

Breckenridge Shelter Geoarchaeology, Trevor John Seekamp

Graduate Theses and Dissertations

My graduate research mainly focuses on Breckenridge Shelter (3CR002), Carroll County, Arkansas. As a geoarchaeologist, my concerns are geomorphological and geological processes affecting the shelter and surrounding hill slope. Breckenridge is one of several similar, Pine Hollow bluff shelters, about Beaver Lake, an impoundment of the White River, in northwest Arkansas.

Classification Of Satellite Time Series-Derived Land Surface Phenology Focused On The Northern Fertile Crescent, Brian Embree Bunker

Graduate Theses and Dissertations

Land surface phenology describes events in a seasonal vegetation cycle and can be used in a variety of applications from predicting onset of future drought conditions, to revealing potential limits of historical dry farming, to guiding more accurate dating of archeological sites. Traditional methods of monitoring vegetation phenology use data collected in situ. However, vegetation health indices derived from satellite remote sensor data, such as the normalized difference vegetation index (NDVI), have been used as proxy for vegetation phenology due to their repeated acquisition and broad area coverage. Land surface phenology is accessible in the NDVI satellite record when images …

Personalized News Recommender Using Twitter, Satya Srinivasa Nirmal Jonnalagedda

Graduate Theses and Dissertations

Online news reading has become a widely popular way to read news articles from news sources around the globe. With the enormous amount of news articles available, users are easily swamped by information of little interest to them. News recommender systems are one approach to help users find interesting articles to read. News recommender systems present the articles to individual users based on their interests rather than presenting articles in order of their occurrence. In this thesis, we present our research on developing personalized news recommendation system with the help of a popular micro-blogging service "Twitter". The news articles are …

Assessment Of Students’ Crisis Communications Skill Increase Based On Classroom Instruction And Second Life™ Training, Gregory C. Jernigan, Jessica R. England, Leslie D. Edgar

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Crisis communication training and skill development are critical to ensure the sustainability of the agriculture industry. The purpose of this study was to assess students’ perceptions of knowledge, ability, and skills on select crisis-related skills, tasks, and activities in order to identify the potential effectiveness of a Second LifeTM (SL) simulation. Pre- and post-test data were collected to determine the potential changes in skill in the seven crisis communication constructs of (a) related knowledge; (b) mass, group, and intrapersonal communications; (c) contingency planning; (d) use of related supplies and tools; (e) identifying learning and training needs; (f) related areas of …