Digital Commons Network^™

Design And Implementation Of An Actively Adjustable Spring Mechanism Via Redundant Actuation, Eleazar Marquez

Theses and Dissertations - UTB/UTPA

This study presents the theoretical results and experimental validation of an adjustable stiffness mechanism. The use of redundant actuation is emphasized in the design of a one-degree-of-freedom Watt II mechanism capable of independently controlling the effective stiffness without a change in equilibrium position. This approach is in contrast to previous spring mechanism designs unable to actively control the spring rate independent of deflection, and has potential applications in various types of suspension and assembly systems. Results indicate that driving the redundantly actuated, unidirectional, spring mechanism requires attaching two direct brush-type direct current motors on each of the two grounded revolute …

Surface Optimization Of High Density Polyethylene And Carbon Nanofiber Composites For The Improvement Of Electromagnetic Shielding Effectiveness, Brandon C. Jarvis

Theses and Dissertations - UTB/UTPA

Nanoreinforced composites of High Density Polyethylene (HDPE) and Carbon Nanofibers (CNF) of varying nanofiber concentration were fabricated via melt mixing. Following fabrication, various metal and metal-nitride thin films were sputter deposited upon the substrates. Volume resistivity measurements of the composite substrates, as well as four point probe analysis of the composites and the deposited films were performed and are reported. Electromagnetic Interference (EMI) Shielding Effectiveness (SE) measurements were performed upon all samples in order to gauge the effects of percolation and the presence of the deposited film(s) upon overall SE. Comparisons of experimental measurements with analytical models available in the …

False Positive Rates In The Neuropsychological Assessment Of Neurologically Intact Bilingual Hispanic American Adults, Cassandra Dayanira Gonzalez

Theses and Dissertations - UTB/UTPA

Hispanic Americans perform more poorly than White Americans on neuropsychological tests, leading to a higher misclassification rate of brain injury (false positives) among Hispanics when using the 50th percentile of published norms as the estimate of preexisting neuropsychological skill. This study aimed to determine if using an individual comparison standard to estimate preexisting skill levels would reduce the number of false positives in a sample of 20 bilingual Hispanic American adults. Two individual comparison standards were used: (a) WMLS-R Picture Vocabulary scores, and (b) WMLS-R Picture Vocabulary scores and WAIS-III Matrix Reasoning scores combined. Both individual comparison standards were found …

Context Versus Rote Learning In The Martial Arts, Pearson F. Klein

Theses and Dissertations - UTB/UTPA

Research has shown that when learning martial arts katas, adults retained the information better “when the katas were taught with the context method than when the katas were taught with the no context method.” (Tovar, M.) It is imperative more experimentation be performed in this area because the findings do not relate to the population of children. Children between ages seven and twelve were instructed in two original katas utilizing two methods of instruction. First the katas with context were taught and then the other taught was purely based on rote completion of the sequential movements. Every subject was tested …

Testing The Neutralizing Effects Of Nonverbal Teacher Immediacy Cues On Offensive Teacher Misbehaviors In Higher Education Classrooms, Claudia Esther Martinez

Theses and Dissertations - UTB/UTPA

The purpose of this study was to determine if the use of nonverbal teacher immediacy cues can neutralize the negative impact that offensive teacher misbehaviors have on student perceptions of teacher credibility, affective learning, and motivation. The sample included a total of 140 participants enrolled in various undergraduate communication and theater courses from a southwestern university. Three one-way ANOVA tests were conducted to test the three hypotheses which proposed that nonverbal teacher immediacy cues may neutralize the negative impact that offensive teacher misbehaviors have on students’ perception of teacher credibility, affective learning, and motivation. Ultimately, findings revealed that teacher immediacy …

Attitudinal Measures Of College Students' Punitiveness Toward Sex Offenders, Antonio Zamorano

Theses and Dissertations - UTB/UTPA

The following experiment investigates punitiveness toward sex offenders using a sample of one hundred sixty students from the University of Texas-Pan American student population recruited from undergraduate introductory psychology courses and compensated with extra course credit. Punitiveness toward sex offenders was measured with six-point bipolar Likert scales using two attitudinal research methodologies: a randomly assigned between group experiment using a manipulated hypothetical crime scenario, and a survey using a shortened version of the Community Attitudes Toward Sex Offenders Scale (CATSOS). A one-way analysis of variance (ANOVA) and multiple comparison tests of attitudinal responses to the hypothetical crime scenario determined that …

The Distribution And Comparative Biogeochemistry Of Silver With Other Selected Trace Metals In Coastal Waters Near Massachusetts, Usa, Christian F. Krahforst

Graduate Doctoral Dissertations

Water samples and hydrologic data were collected during 1994-1996 in New England coastal waters near Massachusetts, USA to examine the distribution of silver and other trace metals (Cu, Pb, Cd, Zn, and Fe) in the coastal systems of Massachusetts and Cape Cod Bays. These investigations were designed to test the hypothesis that silver could serve as a tracer of dispersion of municipal wastewater in Boston Harbor into Massachusetts and Cape Cod Bays and estimate the relative contribution of wastewater discharge to the overall silver budget of the Massachusetts Bays system. Silver concentrations in both particulate and filtered (<0.4 µm) fractions averaged 103 and 117 pmol kg-1 for Boston Harbor, 34 and 10 pmol kg-1 in western Massachusetts Bay, and 11 and 7 pmol kg-1 in the central portion of Massachusetts Bay, respectively. Average Ag concentrations in southern Gulf of Maine coastal waters were 10 and 2 pmol kg-1 for filtered and particulate fractions, respectively. While nearly half of the silver existed in particulate form in Boston Harbor, nearly 80% of the silver in Massachusetts and Cape Cod Bays occurred in the filterable fraction. Coastal water surveys revealed non-conservative Ag behavior and probably the result of incomplete mixing of three or more water masses with unique Ag signatures (e.g., Merrimack River, Boston Harbor, surface and intermediate Gulf of Maine waters). Quasi-steady state mass balance approaches estimate most of the silver entering into the Massachusetts Bays system during the study period was the result of municipal wastewater discharge to Boston Harbor (84-93%).

Multivariate analyses …

Unattainable Beauty: An Analysis Of The Role Of Body Shame And Self-Objectification In Hopelessness Depression Among College-Age Women, Meredith A. Evans

Graduate Doctoral Dissertations

Despite substantial evidence that women suffer from depression at twice the rate of men, the etiology for this difference remains unclear. Prior to puberty, the difference in depression is negligible; however, when adolescence begins, a precipitous rise in female depression occurs that persists across the lifespan. While no definitive biological change has been linked to this phenomenon, objectification theory (Frederickson & Roberts, 1997) can be used to gain insight into the social influences at play during that transitional period. This study of 269 undergraduate women from a northeastern university used structural equation modeling to propose a path leading from self-objectification …

Worker Cooperatives And Revolution: History And Possibilities In The United States, Christopher Wright

Graduate Masters Theses

Worker cooperatives have a long and tortured history, but recently they have been advancing globally on a more stable foundation than before. In this essay I provide a theoretical context for the current growth of cooperatives, drawing on Marxist theory to illuminate their potential. I also consider the sociology and economics of worker cooperatives, in addition to expounding and evaluating their history in the United States.

A case-study of a cooperative printing press in Jamaica Plain gives a more intimate portrayal of worker co-ops, and hopefully provides lessons for future cooperators. I interpret society as on the cusp of a …

Gentility And Gender Roles Within The 18th-Century Merchant Class Of Newport, Rhode Island, Nicki Hise

Graduate Masters Theses

The Capt. Thomas Richardson household rose to prominence in Newport, Rhode Island during the community’s golden age of prosperity in the 18th century when Newport quickly became one of the leading seaports in the New World. However, all prosperity halted due to the hardships and damage Newport suffered during the American Revolutionary War. Much of the city’s property and economic success was destroyed at the hands of occupying British troops, and the Rhode Island community was never able to fully recover. Like others in colonial Newport, Capt. Thomas Richardson achieved genteel status as a merchant, distiller, and slave ship owner …

The Role Of Sulfur In Biomineralization: Argopecten Irradians And The Impact Of Ocean Acidification, Bryanna Joy Broadaway

Graduate Masters Theses

The burning of fossil fuels, and other natural processes, has led to an increase of carbon dioxide (CO₂) in the atmosphere. The equilibration of atmospheric CO₂ with surface waters causes the ocean pH to decrease from the current value of 8.1. Evidence suggests that as the ocean becomes more alkaline, organisms such as the bay scallop, Argopecten irradians¸will become more stressed due to increased energy demands to maintain shell deposition and growth. This stress, as hypothesized here, may cause the deposition of S-bearing organic macromolecules to aid in mineralization as well as the potential for sulfate …

Distributions Of Sharks Across A Continental Shelf In The Northern Gulf Of Mexico, J. Marcus Drymon, Sean P. Powers, John Dindo, Brian Dzwonkowski, Terry A. Henwood

University Faculty and Staff Publications

Declines in shark populations have sparked researchers and fishery managers to investigate more prudent approaches to the conservation of these fish. As managers strive to improve data collection for stock assessment, fisheries-independent surveys have expanded to include data-deficient areas such as coastal regions. To that end, a catch series from a nearshore survey off Alabama was combined with data from a concurrent offshore survey with identical methodology to examine the depth use of sharks across the continental shelf (2–366 m). The combined data set contained 22 species of sharks collected from 1995 to 2008: 21 species in the offshore data …

Product Technical Information, Steel Stud Manufacturers Association

CCFSS Library (1939 - present)

No abstract provided.

Perceptions Of Adjunct Faculty About Their Experiences At Selected Universities In The Upper Midwest Of The United States, Penelope Simons

Theses and Dissertations

No abstract provided.

Ferric Iron Nanoparticle Formation Mediated By Negatively Charged Polypeptides, Vamsi Krishna Aluru

Graduate Theses, Dissertations, and Problem Reports (ETD)

The creation of magnetite particles by magnetotactic bacteria has been of great interest for a number of years. Previous studies have shown that magnetite nanocrystals have been synthesized in the presence of recombinant Mms6 protein. Mms6 plays a vital role in the biomineralization of bacterial magnetite nanocrystals. The objective of this research is to determine the effect of functional group type on size and shape of magnetic nanoparticles formed by biomineralization. Control over the size of nanoparticles is paramount. Use of nanoparticles as contrast agents in MRI is advantageous, as they are small enough to be localized in desired region …

Ecology Of Trifolium Stoloniferum (Muhl. Ex A. Eaton), A Federally Endangered Vascular Plant, At The Fernow Experimental Forest In West Virginia, John Q. Burkhart

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis presents work addressing the ecology of Trifolium stoloniferum, a federally endangered vascular plant species, in the Fernow Experimental Forest, West Virginia. In this thesis, I describe the historical ecology of this species and make a case that at one time it occurred in great abundance in association with trails created by large mammals and humans that intersected rich, open forests. Similar conditions exist at the Fernow Experimental Forest in West Virginia, but instead of large mammals, the requisite soil disturbance, control of competing vegetation, and canopy perforation are created by timber-harvesting related disturbances, particularly gap creation by tree …

Pot Heat Balance Analysis In Continuous Galvanizing Lines, Quang Minh Phuong

Graduate Theses, Dissertations, and Problem Reports (ETD)

Galvanizing is an energy intensive industry. Knowing how much energy is consumed when producing a certain product will help the company in determining which products can be produced to maximize profits. E-GEPDSS was built to explore the potential of saving energy in galvanizing lines by utilizing heat balance analysis. Heat transfer mechanisms of the heat losses for the pot presented in the heat balance are basic heat transfer concepts (i.e. radiation, convection, conduction, and specific heat.;The pot heat balance model was built and applied using the data collected from a host company during the plant visit. Sensitivity analyses were done …

Developing A Cellular Assay For Screening Inhibitors Of Stat4 Phosphorylation, Vivian Marcela Suarez

Graduate Theses, Dissertations, and Problem Reports (ETD)

In order to design better therapeutic strategies, scientists work on understanding the interactions that take place at cell level and have an effect on the immune system. In order to identify a few possible inhibitors that may be up-regulated in tumor environment and that may affect T-cell action, a cellular assay was designed. An Interleukin-12 (IL-12)-responsive murine Th1 cell clone called 2D6 was used as cellular model to study the effects of transforming growth factor-beta (TGF-beta), insulin, and interleukin-6 (IL-6) on the phosphorylation of Signal transducer and activator of transcription 4 (STAT4), a key element in IL-12 signaling. Cells were …

Nanofabrication Of Optofluidic Photonic Crystal Resonators For Biosensing, Henry Bolivar Andagana Junta

Graduate Theses, Dissertations, and Problem Reports (ETD)

Advances in nanofabrication have made possible the development of novel nanophotonics based on Photonic Crystal (PhC) structures. Different types of biosensors have been proposed to take advantage of the unique optical properties of PhCs, which, when combined with microfluidics, provide an enabling approach for biomolecule analysis. In this thesis, nanofabrication of a new biosensor structure integrating a 2D PhC nanocavity resonator with an optofluidic channel is described. The recipes for e-beam lithography of PhC and PhC nanocavity patterns were optimized by carefully tuning the e-beam dose as well as control of the resist baking and development conditions. Two PhC fabrication …

A Comprehensive Simulation Model For Floating Gate Transistors, Steven Joseph Rapp

Graduate Theses, Dissertations, and Problem Reports (ETD)

Floating-gate transistors have proven to be extremely useful devices in the development of analog systems; however, the inability to properly simulate these devices has held back their adoption. The objective of this work was to develop a complete simulation model for a floating-gate (FG) MOSFET using both standard SPICE primitives and also MOSFET models taken directly from foundry characterizations. This new simulation model will give analog designers the ability simulate all aspects of floating-gate device operation including transient, AC and DC characteristics. This work describes the development of this model and demonstrates its use in various applications.

Emotional Intelligence And Facial Affect Recognition Among College Psychopaths Versus Controls, Rebecca L. Schwartz

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study had two purposes: to replicate research on facial affect recognition and to test for differences in emotional intelligence abilities between a college psychopathic and controls population. Two groups were formed based on Psychopathy Personality Inventory-Revised scores with the college psychopathic group scoring above the 75% cut off, and the controls below the 50% cut off. Forty-two college students completed questionnaires including a demographic questionnaire, the Psychopathy Personality Inventory-Revised, the Bar-On EQ-i, and the Illegal Behavior Checklist. They also completed a facial affect recognition task. There were no significant differences between the psychopathic group and the control group on …

An Exploration Of The Spatial Distribution Of National Park Units, Daniel Servian

Graduate Theses, Dissertations, and Problem Reports (ETD)

National Parks can reveal a glimpse into significant aspects of a culture. Visiting and experiencing a National Park can open a window into a culture's heritage, intellectual philosophy, triumphs, and sorrows. As of 2009, the National Park Service administered 393 National Park units, located across America and its territories. The purpose of this paper is to spatially investigate the National Park designation process. Examination of the trends and patterns within the National Park designation process required computation of the data via exploratory data analysis (EDA) and exploratory spatial data analysis (ESDA). This analysis will illustrate significant clusters and correlation between …

Effects Of Acid Mine Drainage And Acid Precipitation On Leaf Litter Breakdown Rates In Appalachian Headwater Streams, Mary Fiona Stewart

Graduate Theses, Dissertations, and Problem Reports (ETD)

Acid precipitation and acid mine drainage have dramatically altered chemical conditions and biological assemblages in streams throughout the central Appalachians. Effects of acidification on functional stream processes such as organic matter decomposition, however, remain poorly understood. The objectives of this study were to: (1) quantify differences in organic matter decomposition among reference streams, streams impacted by acid precipitation, and streams impacted by acid mine drainage; and (2) determine if lowered decomposition rates are the result of reduced microbial activity or altered invertebrate shredder assemblages or both. I quantified water chemistry, organic matter decomposition, microbial activity, and macroinvertebrate community structure in …

Evaluating The Effects Of The Blennerhassett Island Bridge Crossing (Ohio River) On Soil, Vegetation, And Wildlife, Joshua Allen Vance

Graduate Theses, Dissertations, and Problem Reports (ETD)

Corridor D was one of the original 23 highway corridors selected by the Appalachian Highway Development System in 1965 and stretches from Bridgeport, West Virginia to Cincinnati, Ohio. The last piece of Corridor D to be completed was the Blennerhassett Island Bridge which crosses over the Ohio River and Blennerhassett Island near Parkersburg, West Virginia and Belpre, Ohio. The Blennerhassett Island Bridge is a tied-arch style bridge about 1,220 m in length and 24 m above the ground and water surface. Construction of the bridge began in March 2005 and the bridge was opened to the public in June 2008. …

Hydrologic Soil Grouping Determination For Appalachian Minesoils, Anthony Willard

Graduate Theses, Dissertations, and Problem Reports (ETD)

The hydrologic soil group refers to the infiltration potential of the soil after prolonged wetting. This classification system separates soils into four hydrologic groups (A, B, C, and D), based upon the intake and transmission of water under conditions of maximum yearly wetness. Group A has the lowest runoff potential and D the highest. Several soil properties are used to determine the hydrologic soil groupings. In the study of the hydrologic soil nature, soil properties that affect infiltration, such as bulk density, porosity and texture, should be considered. Associated factors that affect infiltration in the field are slope and vegetation. …

Three Essays On Caps Market And Unspanned Volatility, Harumi Hattori

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this thesis we study the caps market. Caps are a contract where the interest rates are capped at some fixed value r¯. Caps consist of caplets which are European options on the forward rates called LIBOR (the London Inter-Bank Offer Rates). Caps are the derivatives of LIBOR. However, their relation is not so simple as the relation between a stock and its derivatives. One important difference is that the volatility in one market does not affect the volatility of the other market as much as in the stock and its derivative markets. This phenomenon is termed unspanned stochastic volatility …

Three Essays On The Foreign Exchange And Equity Returns, Alina F. Klein

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation contains three essays dealing with current issues in the foreign exchange and equity exchange markets. The first essay observes that both markets display behaviors akin to momentum and mean reversion. This essay implements a trading strategy combining mean reversion and momentum in foreign exchange markets. The strategy was originally designed for equity markets, but it also generates abnormal returns when applied to uncovered interest parity deviations for five countries. I find that the pattern for the positions thus created in the foreign exchange markets is qualitatively similar to that found in the equity markets. Quantitatively, this strategy performs …

Sub-Surface Stratigraphy And Petrophysical Analysis Of The Middle Devonian Interval Of The Central Appalachian Basin; West Virginia And Southwest Pennsylvania, Matthew Louis Boyce

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the central Appalachian basin, the Middle Devonian organic-rich shale interval, including the Marcellus Shale, is an important target for natural gas exploration. It has emerged as a giant unconventional resource play due to aerial extent and potential for individual wells to produce large volumes of gas. The Marcellus Shale is well studied on the surface without the incorporation of the subsurface stratigraphy. However, to fully understand the Marcellus economic potential it is important to investigate and map the related Middle Devonian sub-surface stratigraphic units. The interval studied includes the Onondaga Limestone (Eifelian), Marcellus Shale (Eifelian), Purcell Limestone (Eifelian), Mahantango …

Mandatory Reporting In The Context Of Home Visitation Programs, Danielle Marie Davidov

Graduate Theses, Dissertations, and Problem Reports (ETD)

Each year in the United States, 4.8 million physical assaults and rapes are committed against 1.5 million women by an intimate partner. An estimated 3.3 to 10 million children are exposed to some form of intimate partner violence (IPV) in their own homes annually. Although mandatory reporting laws regarding child abuse and/or neglect are implemented in all 50 U.S. states, the extent to which these laws are appropriate for IPV between adults and children exposed to IPV is undetermined. A comprehensive examination of the perspectives of those required to report abuse is critical, as their roles as mandated reporters often …

Understanding Plasmas Through Ion Velocity Distribution Function Measurements, Saikat Chakraborty Thakur

Graduate Theses, Dissertations, and Problem Reports (ETD)

This work concerns measurements of ion velocity distribution functions (IVDF) using three different diagnostic techniques in expanding argon plasmas generated by two different helicon plasma sources. A theoretical prediction by Lieberman et al., of enhanced upstream ionization by electrons accelerating upstream, due to the formation of a stable electrostatic current-free double layer (DL) in an expanding plasma, was verified through laser induced fluorescence (LIF) and retarding field energy analyzer (RFEA) measurements of the IVDF and Langmuir probe measurements of the plasma density. Keeping all other external source parameters constant and varying only the operating frequency of the helicon source HELIX, …