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Articles 1 - 30 of 184
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Surface Wetting And Friction Studies Of Nano-Engineered Surfaces On Copper Substrate, Julius Sheldon Morehead
Surface Wetting And Friction Studies Of Nano-Engineered Surfaces On Copper Substrate, Julius Sheldon Morehead
Graduate Theses and Dissertations
Nano-engineered-textures on a material surface can dramatically improve the wetting and non-wetting properties of a surface, and they also show promise to address friction issues that affect surfaces in contact. In this work, aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) was used to produce nano-textures on copper (Cu) substrates. A study was performed to examine the effects of changing the annealing conditions and a-Si thickness on nano-texture formation. The creation of various nano-topographies and chemically modifying them using octafluorocyclobutane (C4F8) was performed to control hydrophilicity, hydrophobicity, and oil affinity of nano-textured surfaces. A video-based contact angle measurement system was used …
Influence Of Recycled Asphalt Shingles On Asphalt Binder Content, Mixture Stiffness, And Laboratory Rutting Performance, Joshua David King
Influence Of Recycled Asphalt Shingles On Asphalt Binder Content, Mixture Stiffness, And Laboratory Rutting Performance, Joshua David King
Graduate Theses and Dissertations
Recycled asphalt shingles (RAS) is a technology in which pavement costs can be reduced significantly and pavement properties may be enhanced. Also, incorporating shingles into pavements reduces the impacts of waste shingles in landfills, preserving our environment. However, for this new technology to be practical for implementation, a better understanding of how the ground shingles affect the properties of the asphalt is necessary. The purpose of this research was to examine the effects of recycled asphalt shingles on asphalt binder content, mixture stiffness, and laboratory rutting performance. For this project, shingles were added to hot mix asphalt mixtures at 2.5, …
Removal Of Disinfection By-Product Precursors Using Magnetic Ion Exchange (Miex(R)): The Effects Of Ph And Source Water Variability, Sarah Cousins
Removal Of Disinfection By-Product Precursors Using Magnetic Ion Exchange (Miex(R)): The Effects Of Ph And Source Water Variability, Sarah Cousins
Graduate Theses and Dissertations
Disinfection by-products (DBPs) form as an unintended result of drinking water disinfection, from chemical reactions between disinfectants (e.g., free chlorine) and naturally occurring dissolved organic matter (DOM). At present, 11 DBPs are regulated in treated drinking waters due to potential adverse health effects, including four trihalomethanes (THMs). Despite nearly 40 years of DBP research, compliance with DBP regulations remains a challenge for many drinking water treatment plants (DWTPs), including the four DWTPs located on the Beaver Lake Reservoir in Northwest Arkansas. Due to the high net negative surface charge on DOM, anion exchange is one potentially viable method for removing …
Gene Expression And Physiological Analyses To Study Metabolic Shifts In Medicago Truncatula Subjected To Biotic Stresses, Michelle Ryan Martin
Gene Expression And Physiological Analyses To Study Metabolic Shifts In Medicago Truncatula Subjected To Biotic Stresses, Michelle Ryan Martin
Graduate Theses and Dissertations
Plants are frequently under attack from pests and deploy various defense mechanisms to fight off predators. Many plant defenses are induced following herbivory or pathogen infection. An investment in defense could potentially lead to a diversion of metabolic resources away from primary metabolism, including reduction in plant commitment to photosynthesis. In this thesis, changes in expression levels of representative genes for primary and secondary metabolism were studied using real-time polymerase chain reaction (PCR) in Medicago truncatula Gaertner subjected to beet armyworm (Spodoptera exigua H¨¹bner) damage or Phoma medicaginis Malbr. & Roum. infection. Photosynthetic yield was also measured using chlorophyll fluorescence …
The Marked Tree Site: Evaluation Of Geosynthetic Reinforcements In Flexible Pavements, Taylor Mitchell Goldman
The Marked Tree Site: Evaluation Of Geosynthetic Reinforcements In Flexible Pavements, Taylor Mitchell Goldman
Graduate Theses and Dissertations
This document presents findings from a three-year, full-scale, field research project aimed at determining the benefits of using geosynthetic reinforcements to improve the performance of flexible pavements constructed over poor subgrade soils. The test site, known as the Marked Tree site, is an 850-ft (258-m) long segment of low-volume frontage road along Highway 63 in the town of Marked Tree, Arkansas. The site, constructed in 2005, consists of seventeen 50-ft (15.2-m) long flexible pavement test sections with various types of geosynthetic reinforcements (woven and nonwoven geotextiles, and geogrids), which were all positioned at the base-subgrade interface, and two different nominal …
Increasing Profitability Of Small Scale Cocoa Farmers Through Optimizing Replacement Rate, Mahrizal
Increasing Profitability Of Small Scale Cocoa Farmers Through Optimizing Replacement Rate, Mahrizal
Graduate Theses and Dissertations
The objective of this study is to empirically estimate the optimum annual replacement rate and age of replacement of cocoa trees in order to maximize the net present value of four production practices over time. The study examines the costs and returns of four common cocoa production systems in Ghana associated with changes in cocoa prices, fertilizer prices, inflation rates, and labor prices. While this study focuses on cocoa, the method is applicable to any tree crop industry. This study uses empirical yield curves and cost of production data from Ghana to determine when and what percentage of a cocoa …
Inventory Models For Intermittent Highly Variable Demand And Policy Parameter Adjustments To Meet Desired Service Level Requirements, Yasin Unlu
Graduate Theses and Dissertations
This dissertation consists of three assays. The first assay examines the robustness of lead time demand models for the continuous review (r;Q) inventory policy. A number of classic distributions as well as distribution selection rules are examined under a wide variety of demand conditions. First, the models are compared to each other by assuming a known demand process and evaluating the errors associated with using a different model. Then, the models are examined using a large sample of simulated demand conditions. Approximation results of inventory performance measures - ready, rate excepted number of backorders and on-hand inventory levels are reported. …
Integrated Planning For Rural Rail Transportation, Jeffrey Cohan Gwaltney
Integrated Planning For Rural Rail Transportation, Jeffrey Cohan Gwaltney
Graduate Theses and Dissertations
Population growth in rural areas has led to new interest in rail transportation. Planning a passenger rail system involves numerous difficult decisions, most representing a trade-off between customer service and cost. In this work, we attempt to integrate many of these planning decisions. We consider strategic decisions such as station location and vehicle procurement, as well as tactical issues that include vehicle scheduling. Our integrated model exploits the linear network structure that best suits many rural American communities, including Northwest Arkansas. Due to the intractability of the integrated rail planning problem, we have developed a customized heuristic approach to solve …
Disclosing An Invisible Disability During The Interview Process: A Qualitative Study, John Elias Sassin
Disclosing An Invisible Disability During The Interview Process: A Qualitative Study, John Elias Sassin
Graduate Theses and Dissertations
Rehabilitation professionals, persons with disabilities and employers were asked to participate in a focus group interview exploring the phenomena of disclosing invisible disabilities during the interview process. This Qualitative study examined disclosure of disability from each stakeholder's perspective in an effort to understand its impact on the interview. After transcribing the focus group interview and analyzing the data; five themes emerged reflecting each stakeholder's views on disclosure. The themes revealed the persistence of attitudinal barriers that people with disabilities face in seeking employment; if and when a person should disclose; what are the positive and negative aspects of disclosure and …
A Comparison Of Internet Marketing Methods Utilized By Higher Education Institutions, Joseph Clayton Mccoy
A Comparison Of Internet Marketing Methods Utilized By Higher Education Institutions, Joseph Clayton Mccoy
Graduate Theses and Dissertations
Use of Internet marketing techniques in higher education to attract prospective students is relatively new. While the research is recent, there are several studies that identify what is most valuable to students seeking information on college web sites. Higher education is now facing increasing competition from for-profit schools and reduced funding from typical sources. This study examines how two different Carnegie classifications use Internet marketing techniques and identifies if there is a difference in how much they use these techniques. Content techniques and search engine optimization (SEO) techniques were examined for 56 higher education institutions in this study. Of the …
Investigation Of A Floating Load Buck Dc-Dc Switching Converter, Hong Tan
Investigation Of A Floating Load Buck Dc-Dc Switching Converter, Hong Tan
Graduate Theses and Dissertations
A floating load buck DC-DC switching converter was analyzed, simulated, designed and prototyped. The floating load buck converter is first compared to the conventional buck converter. It was found that both the floating load buck converter and conventional buck converter exhibit similar conversion characteristics despite the differences in the placement of their output inductors. A floating load buck converter was designed to be used as a high-voltage off-line light-emitting diodes (LEDs) driver using a Texas Instruments' TPS92001 controller. Finally, the characteristics of this floating load buck converter LED driver were experimentally examined.
Teachers' Perceptions Toward The Secondary Physical Education Program In The State Of Kuwait, Khaled A. Al-Kandari
Teachers' Perceptions Toward The Secondary Physical Education Program In The State Of Kuwait, Khaled A. Al-Kandari
Graduate Theses and Dissertations
The purpose of this research was to determine the perceptions of physical education teachers and supervisors toward the secondary physical education program in eight domains in the State of Kuwait. Stratified and cluster sampling were used to select two schools of female teachers and two schools of male teachers from each district (6 districts); therefore, 24 schools were selected randomly. One hundred thirty-eight physical education teachers were selected and 66 supervisors were selected. A four-point rating scale (i.e., strongly disagree to strongly agree) and open-ended questions were included in the survey. Cronbach's alpha reliability, descriptive statistics, and independent sample t …
Design Of A Low Noise Amplifier For Wireless Sensor Networks, Ting Liu
Design Of A Low Noise Amplifier For Wireless Sensor Networks, Ting Liu
Graduate Theses and Dissertations
CMOS technology becomes important in Radio Frequency (RF) communication systems which include both a receiver and a transmitter. In a high performance radio receiver, the Low Noise Amplifier (LNA) is the first circuit, and its noise performance dominates the entire receiver. Depending upon the system in which they are used, LNAs can be designed according to various topologies and structures. The LNA needs to have matched input impedance, and at the same time it should amplify the small amplitude input signal without adding too much noise and still have the minimal power consumption. It also needs a good interface with …
Design Of An 866 Mhz On-Chip Frequency Synthesizer, Phaniraj Joshi
Design Of An 866 Mhz On-Chip Frequency Synthesizer, Phaniraj Joshi
Graduate Theses and Dissertations
There is a strong need for stable frequency references with large tuning ranges in today's communication systems. While the crystal oscillators assure good frequency stability, it is not possible to achieve a large frequency range by tuning the passive components attached to them. Frequency synthesizers are usually used for this purpose because of their ability to produce a variety of output frequencies. The Phase Locked Loop (PLL) based frequency synthesizer is the most preferred of all types of synthesizers available because of its additional features like programmability, low noise and low cost as well as high accuracy and stability. The …
Cognitive Agendas And Legal Epistemology, Danny Marrero
Cognitive Agendas And Legal Epistemology, Danny Marrero
Graduate Theses and Dissertations
The domain of legal epistemology is defined from two alternative perspectives: individual epistemology and Social epistemology. Since these perspectives have different objects of evaluation, their judgments privilege and exclude different sets of information. While methodological individualism is concerned with justified beliefs of individual knowers, the Social angle focuses on the institutional conditions of knowledge. I will show that the information that is respectively excluded by both the individual and the Social concepts of legal epistemology weaken their respective evaluations. With this in mind, I will explore one new option of defining legal epistemology. This alternative is more comprehensive, in the …
Creativity In Triadic Supervision: Using Mandalas To Impact The Working Alliance, Kelly Agnes Dunbar
Creativity In Triadic Supervision: Using Mandalas To Impact The Working Alliance, Kelly Agnes Dunbar
Graduate Theses and Dissertations
This qualitative study investigated the use of mandalas as a creative approach with the potential to impact the supervisory working alliance within the context of triadic supervision. Participants (n=7) included master's level counselors-in-Training (CITs), all female, and ranging in age from 23 to 44. Data generated by the formal interviews gained support for using mandalas as a creative approach in triadic supervision as they revealed the potential to impact the working alliance and the goals, task, and bond therein. Of further importance was the finding that the bond between paired CITs in triadic supervision sessions was also impacted by the …
Single Mothers In College: The Effect Of Selected Variables, Rickey Booker
Single Mothers In College: The Effect Of Selected Variables, Rickey Booker
Graduate Theses and Dissertations
Single parent mothers who are currently in poverty may find it difficult to find routes out of poverty and/or even to enrolling in college. Little empirical research has been conducted on low-income single parent mothers who attempt to enroll, persist and graduate college. The current research has shown that single parents are at a high risk of dropping out of college because of many barriers including poverty related issues. This study examined women who had at least one child or dependent, were in poverty, and were first time beginners in college. The purpose for conducting this study was to identify …
Adaptive Intensity Modulated Radiation Therapy Planning Optimization With Changing Tumor Geometry And Biology Enforcing Both Cumulative And Fraction Size Dose Constraints, Behlul Saka
Graduate Theses and Dissertations
Intensity Modulated Radiation Therapy (IMRT) is a modern technique of delivering radiation treatments to cancer patients. In IMRT technology, intensities must be chosen for the many small unit grids into which the beams are divided to produce a desired distribution of dose at points throughout the body with the goal of maximizing dose delivered to the tumor while sparing healthy tissues from excessive radiation and keeping dose homogeneous across the tumor. Although IMRT plans are optimized as a single overall treatment plan, they are delivered over 30-50 treatment sessions (fractions) and both cumulative and per-fraction dose constraints apply. The extended …
A Nietzschean Account Of Human Flourishing: Affirming The Will To Power Inside The Contours Of Friendship, Christian Joshua Roos
A Nietzschean Account Of Human Flourishing: Affirming The Will To Power Inside The Contours Of Friendship, Christian Joshua Roos
Graduate Theses and Dissertations
In this dissertation, I examine Friedrich Nietzsche's notion of the will to power, his account of friendship and his understanding of human flourishing. Through textual analysis, I offer a new way of interpreting the will to power, as the achieving of self-realization. The process of achieving self-realization is undergirded by the satisfaction of seven existential needs that are rooted in the paradoxical human conflict between instincts and consciousness. The existential needs are the need for a frame of orientation, the need for devotion, the need for unity, the need for rootedness, the need for stimulation, the need for effectiveness and …
Factors Determining Media Coverage Of Meat And Poultry Recalls: Evidence From The Ap Newswire, Thais Fregonesi Carvalho
Factors Determining Media Coverage Of Meat And Poultry Recalls: Evidence From The Ap Newswire, Thais Fregonesi Carvalho
Graduate Theses and Dissertations
Food safety is an important public health issue. Product recalls are an important part of the overall food safety system and occur when potentially unsafe products enter the marketplace. However, it is important that information about the recall ultimately reaches the public. This research assesses the publicity that recalls receive by the popular media. The focus is specifically on recalls of meat and poultry products. Publicity is measured by coverage in the AP Newswire. Data were gathered from the United States Department of Agriculture's Food Safety and Inspection Service (FSIS) and cover meat and poultry recalls from 1982 to 2009. …
The Design, Synthesis And Application Of A Novel Class Of N-Heterocyclic Carbene Catalysts, Abigail Lynn Hubbard
The Design, Synthesis And Application Of A Novel Class Of N-Heterocyclic Carbene Catalysts, Abigail Lynn Hubbard
Graduate Theses and Dissertations
A copper carbenoid representative of a novel class of N-heterocyclic carbene (NHC) catalysts has been synthesized. This compound was characterized by X-ray crystallography and was found to confirm the rationale of our synthetic design: The C2-symmetric structure places four stereocenters in close proximity (<5Å) to the reactive site of the carbene via a trans-annular gearing effect. The copper carbenoid was found to catalyze the hydrosilylation of prochiral ketones with superb selectivity in high yield.
Perception Of Aquifer Depletion And The Effects Of Land Use Change Across The Madaba Plain, Jordan, Mohammad Salem
Perception Of Aquifer Depletion And The Effects Of Land Use Change Across The Madaba Plain, Jordan, Mohammad Salem
Graduate Theses and Dissertations
In Jordan, demand for water for agricultural purposes has put a high strain on aquifer resources. Water mining, erosion, and desertification have all increased as global temperatures rise. This along with fragmentation of the landscape have altered the environment in a profound way. The Madaba Plain was chosen for this study due to the agricultural activities that take place there, as well as the proximity to a number of population centers. The purpose of the study is to examine how fragmentation of irrigated landscape has affected the aquifers underneath, while taking into account perceptions of risk of the local population. …
Fathers And Their Views On Discussing Sex And Sexuality With Their Daughters, Kindann M. Stone
Fathers And Their Views On Discussing Sex And Sexuality With Their Daughters, Kindann M. Stone
Graduate Theses and Dissertations
The purpose of this research project was to identify characteristics and perceptions of fathers associated with discussions about sex and sexuality with their daughters. Parental communication, education, and value sharing reduces the risk of STD's and teen pregnancy. Participants were fathers (N=108) who were recruited by their daughters who were attending a Southeastern University. Demographics were utilized and researcher developed modified scales used in previous studies (citation). The newly developed scales were the Sexual Knowledge Inventory (SKI), Value of Self-Efficacy of Sexuality Communication (VSESC), Safe Sex of Self Efficacy of Sexuality Communication (SSSESC), Father's Role as Sex Educators Outcome Expectancy …
Hospitality Students Perceptions About High Risk Behaviors In Relation To Destructive Behaviors And Decision Making, Boris A. Roslov
Hospitality Students Perceptions About High Risk Behaviors In Relation To Destructive Behaviors And Decision Making, Boris A. Roslov
Graduate Theses and Dissertations
This study investigated hospitality students' perceptions regarding alcohol consumption and personal actions related to high risk behaviors. Those behaviors included: sexual encounters and binge drinking, and their effect on academic tasks and performance. The study investigated whether the hospitality student who is employed full time consumes alcohol at a higher level than a hospitality student does that is not employed full time.
Foliar Symptoms Of Acute Ozone Injury And Exposure Response Characteristics Of Select Native Perennials, Susan Denise Frey
Foliar Symptoms Of Acute Ozone Injury And Exposure Response Characteristics Of Select Native Perennials, Susan Denise Frey
Graduate Theses and Dissertations
Twenty seven perennial species native to the Eastern Temperate Forests Level I Ecoregion were exposed to an acute ozone (O3) treatment consisting of a target peak O3 concentration of 2.0 ppm for 30 minutes in a closed chamber environment, during the summer of 2010. Plants were evaluated for visible foliar injury symptoms and symptoms were described and photographically documented. Ten of the 27 species developed visible foliar injury in which interspecific and intraspecific response to O3 was observed. A severity index was used to compare response to acute ozone exposure for the ten species displaying visible foliar injury. Species showing …
Factors Influencing Teaching Efficacy Among Kansas Career And Technical Education Faculty, Douglas Lee Younger
Factors Influencing Teaching Efficacy Among Kansas Career And Technical Education Faculty, Douglas Lee Younger
Graduate Theses and Dissertations
The purpose of this study was to examine the levels of teaching efficacy among postsecondary career and technical education faculty at Kansas technical and community colleges. Postsecondary career and technical education faculty at Kansas technical and community colleges were asked to complete an instrument designed to measure their levels of teaching efficacy based upon a modified version of the Teachers' Sense of Efficacy Scale, originally developed by Woolfolk and Hoy (1998). The entire population of postsecondary career and technical education faculty from Kansas technical and community colleges (N=726) were surveyed and a total of n=181 (24.9%) completed the instrument. Data …
Assessing Biodegradable Containers For Growing Long-Term Greenhouse Crops In Subirrigation System, Stephanie A. Beeks
Assessing Biodegradable Containers For Growing Long-Term Greenhouse Crops In Subirrigation System, Stephanie A. Beeks
Graduate Theses and Dissertations
The objective for this research was to assess the efficacy of biodegradable containers compared to plastic containers for the production of long-term crops using a subirrigation system. Plastic and various biocontainers were used to grow `Rainier Purple' cyclamen (Cyclamen persicum L.) in ebb-and-flood benches. After 15 weeks, the physical properties of the containers were tested. The used plastic containers had strengths of 23.3, 23.5 and 21.9 g for the bottom, middle and top zones respectively. The peat, dairy manure and wood fiber containers had strengths of less than 2 kg for each zone. The peat, dairy manure, wood fiber and …
Enhancing Soybean Profitability Using Portfolio Theory, Osemenkhian Cynthia Onyechere
Enhancing Soybean Profitability Using Portfolio Theory, Osemenkhian Cynthia Onyechere
Graduate Theses and Dissertations
The purpose of this study was to estimate the effect of utilizing portfolio theory on producers' profitability in the production of soybeans in three test locations - Keiser, Marianna and Rohwer - in Arkansas. The study used empirical yield data, their variances and covariances over a nine year period (2002-2010) in selecting a portfolio of soybean varieties that maintains or increases yield while minimizing the yield risk. Furthermore, carbon emissions associated with soybean production was estimated by modeling the effect of a potential carbon tax as well as the potential benefit of carbon offset payments resulting from carbon sequestration. The …
Army Transformation: What Does It Mean?, David Jerome
Army Transformation: What Does It Mean?, David Jerome
Graduate Theses and Dissertations
The way in which senior U.S. Army leaders such as the chiefs of staff define transformative change is important, especially if the meaning of that term is to be interpreted as originally intended by Army field grade officers. An Army chief of staff is responsible for creating a vision and establishing goals for the future, and field grade officers are responsible for pursuing that vision and those goals by implementing objectives that endeavor to arrive at the desired ends. By using both qualitative and quantitative methods, this research analyzes what each of the three chiefs of staff, who have served …
Exploring First Generation African American Graduate Students: Motivating Factors For Pursuing A Doctoral Degree, Stephanie G. Adams
Exploring First Generation African American Graduate Students: Motivating Factors For Pursuing A Doctoral Degree, Stephanie G. Adams
Graduate Theses and Dissertations
The purpose for conducting the study was to examine the factors that motivate African-American first-generation students to pursue doctoral education at a four-year public university. There has been little research on the influence academic or non-academic factors have on first-generation graduate student motivation. Similarly, little research exists that explored how factors might vary by ethnicity. Based on the projected increase of post-baccalaureate enrollment each year (Aud, Hussar, Planty, Snyder, Bianco, Fox, Frohlich, Kemp, Drake, 2010), first-generation African-Americans will become more interested in attending graduate school. It is important to gain a better understanding of the factors and influences that impact …