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Modeling wild type and mutant glutathione synthetase.

Description: Glutathione syntethase (GS) is an enzyme that belongs to the ATP-grasp superfamily and catalyzes the second step in the biosynthesis of glutathione. GS has been purified and sequenced from a variety of biological sources; still, its exact mechanism is not fully understood. Four highly conserved residues were identified in the binding site of human GS. Additionally, the G-loop residues that close the active site during catalysis were found to be conserved. Since these residues are important for catalysis, their function was studied computationally by site-directed mutagenesis. Starting from the reported crystal structure of human GS, different conformations for the wild type and mutants were obtained using molecular dynamics technique. The key interactions between residues and ligands were detected and found to be essential for enzyme activity.
Date: August 2004
Creator: Dinescu, Adriana

'...and one of time.': A Composition for Full Orchestra with Narration

Description: ‘...and one of time.' is a reinterpretation of a small musical moment from Philip Glass' opera, Einstein on the Beach, centered around the phrase "Berne, Switzerland 1905." This reinterpretation is realized through the use of several different compositional techniques including spectral composition, micropolyphony and dodecaphony, as well as the application of extra-musical models developed by Alan Lightman, John Gardner, Italo Calvino and Albert Einstein.
Date: December 1999
Creator: Rinker, John Thomas

Development of a Coaxiality Indicator

Description: The geometric dimensioning and tolerancing concept of coaxiality is often required by design engineers for balance of rotating parts and precision mating parts. In current practice, it is difficult for manufacturers to measure coaxiality quickly and inexpensively. This study examines feasibility of a manually-operated, mechanical device combined with formulae to indicate coaxiality of a test specimen. The author designs, fabricates, and tests the system for measuring coaxiality of holes machined in a steel test piece. Gage Repeatability and Reproducibility (gage R&R) and univariate analysis of variance is performed in accordance with Measurement System Analysis published by AIAG. Results indicate significant design flaws exist in the current configuration of the device; observed values vary greatly with operator technique. Suggestions for device improvements conclude the research.
Date: December 1999
Creator: Arendsee, Wayne C.

Chemotactic Response of Lumbricus terrestris Coelomocytes to Larval and Adult Stages of Rhabditis pellio

Description: Experiments were performed to assess the suitability of Rhabditis pellio, a nematode found in earthworms, as a challenge organism for use in development of a biomarker assay to determine the potential of chemicals to suppress the immunocompetence of the non-specific immune system. To accomplish this goal, information on the life cycle of R. pellio was determined; including effects of incubation time and temperature on growth rates; along with information on the immune response elicited in the earthworm, Lumbricus terrestris. Immune parameters measured were coelomocyte migration toward and attachment to R. pellio larvae and adults. Preliminary background information showed that R. pellio has potential as a challenge organism for development of a biomarker assay.
Date: December 1999
Creator: Medrano, Jennifer Centurion

The Concept of Dignity in the Early Science Fiction Novels of Kurt Vonnegut.

Description: Kurt Vonnegut's early science fiction novels depict societies and characters that, as in the real world, have become callous and downtrodden. These works use supercomputers, aliens, and space travel, often in a comical manner, to demonstrate that the future, unless people change their concepts of humanity, will not be the paradise of advanced technology and human harmony that some may expect. In fact, Vonnegut suggests that the human condition may gradually worsen if people continue to look further and further into the universe for happiness and purpose. To Vonnegut, the key to happiness is dignity, and this key is to be found within ourselves, not without.
Date: May 2003
Creator: Dye, Scott Allen

Differences in Mother and Father Perceptions, Interactions and Responses to Intervention with a Special-needs Adoptive Child.

Description: Parents' perceptions of their child's behavior may differ for mothers and fathers. Differences in parental perception may also be apparent in cases of special needs adoptive families with high demands of their child for time, interventions and attention. This paper examines the differences in mother-child and father-child interactions, child behavior as reported by mothers, and fathers and changes in both after participation in an intervention program. Results suggest notable differences between mothers' and fathers' parent-child interaction scores and reports of child behavior. In addition, interaction scores and behavior reports showed some correlations. Finally, there seemed to be notable differences in the trends for the Child Behavior Checklist compared to the two attachment measures (Randolph Attachment Disorder Questionnaire and Beech Brook Attachment Disorder Checklist). Several possible explanations for mother and father differences are discussed.
Date: August 2004
Creator: Meland, Angela M.

The Effects of Timed Readings on Recall and Comprehension in a Child with Asperger's Syndrome.

Description: The effects of timed readings on recall and comprehension in a child with Asperger's syndrome were examined by employing a multiple-baseline design across two books with reversals. Recall timings consisted of the student's free-say compilation of what she just read. Comprehension tests consisted of the participant's answers to predetermined questions after her recall period. No consequences or feedback was given during any of the conditions. Results indicate that, initially, as the time required to read decreased, the number of unrelated words during the recall period for the two books also decreased. Related words were not as affected. Scores on comprehension tests were high. There was, however, little correspondence between the participant's recall words and the main ideas answered correctly in the comprehension test.
Date: December 2005
Creator: Young, Christina A.

Effects of Hedonic and Utilitarian Shopping Satisfaction on Mall Consumption

Description: The modern consumer expects a consumption experience with both hedonic and utilitarian rewards during a single visit to the mall. The orchestrating of both hedonic and utilitarian benefits in one visit challenges mall management and retailers to deliver the maximum shopping experience. This study seeks to reveal relationships among six variables: demographic characteristics, mall shopping orientation, mall perception, hedonic satisfaction, utilitarian satisfaction, and mall consumption. The intercept survey was conducted at a major entertainment-themed mall in north Texas. Multiple regression analyses (N = 202) indicate that demographic characteristics and mall shopping orientation were significant predictors of mall perception. Also, two mall perception factors (Sensation and Physical Environment) were predictors of hedonic and utilitarian mall shopping satisfaction. However, hedonic and utilitarian mall shopping satisfaction were found not to predict mall consumption in terms of cross-shopping, money spent, and time spent.
Date: August 2002
Creator: Buhrman, Tiffany

The Effects of Alternative Contingencies on Instruction Following.

Description: The purpose of this experiment was to evaluate the effects of alternative contingencies on instruction following by an ABA design. Three college students consistently pressed keys 1-5-3 and 4-8-6 in the presence of the written instruction "Press 153" or "Press 486." During condition A, the contingencies for following and not following the instruction were the same: CON FR5 FR5 and CON FR20 FR20. During condition B, the contingencies for following and not following the instruction were different: CON FR20 FR5. For one participant, the schedule of reinforcement was then changed to FR30. The results showed that subjects followed instructions when the schedule of reinforcement was the same for instruction following and not following.
Date: May 2003
Creator: Patti, Nicole

The Effect of Punishment Threat on Children's Ability to Resist Temptation to Transgress and Lie

Description: Children's response to a resistance-to-temptation (RTT) task was investigated under three punishment threat conditions: negative consequence, removing an anticipated reward, and no explicit punishment. Ninety first and second graders participated in the RTT task and seventy-three parents completed the Behavior Assessment System for Children and the Psychopathy Screening Device. As only 4% of children transgressed, results are unclear. Hypotheses tested using approximations of transgression showed no differences in RTT. Children with temperaments characterized by hyperactivity, impulsivity, attention problems, and conduct problems (HIA-CP) had the highest levels of psychopathic traits compared to all others. In addition, spanked children were rated as having significantly more behavioral problems than non-spanked children. Limitations of the current study and suggestions for future research are discussed.
Date: December 2001
Creator: Collins, Michelle

Accuracy Variations in Human Facial Identification Based on Time of Exposure.

Description: This study examined the relationship between time of exposure to the human face and accurate subsequent photo line-up identification. A volunteer group of 124 undergraduate students was divided into three approximately equal sized subgroups. The three groups were then exposed to a video or a portion of a video depicting a theft. Exposure times ranged from two minutes to 30 seconds. The subjects were then given a questionnaire and shown a photo line-up of the mock perpetrator and five foils. Subjects were asked to identify the perpetrator and mark that identification on the questionnaire. Results of the experiment indicated that the longer a subject was exposed the greater the possibility of an accurate identification.
Date: December 2006
Creator: Cowle, Kenneth M.

Hungering for Independence: The Relationship between Food and Morale in the Continental Army, 1775-1783

Description: An adequate supply of the right kinds of foods is critical to an army's success on the march and on the battlefield. Good food supplies and a dire lack of provisions have profound effects on the regulation, confidence, esprit de corps, and physical state of an army. The American War of Independence (1775-1783) provides a challenging case study of this principle. The relationship between food and troop morale has been previously discussed as just one of many factors that contributed to the success of the Continental Army, but has not been fully explored as a single issue in its own right. I argue that despite the failures of three provisioning system adopted by the Continental Congress - the Commissariat, the state system of specific supplies, and the contract system - the army did keep up its morale and achieve the victory that resulted in independence from Great Britain. The evidence reveals that despite the poor provisioning, the American army was fed in the field for eight years thanks largely to its ability to forage for its food. This foraging system, if it can be called a system, was adequate to sustain morale and perseverance.
Date: May 2016
Creator: Maxwell, Nancy

Highly Stretchable Miniature Strain Sensor for Large Dynamic Strain Measurement

Description: This thesis aims to develop a new type of highly stretchable strain sensor to measure large deformation of a specimen subjected to dynamic loading. The sensor was based on the piezo-resistive response of carbon nanotube(CNT)/polydimethysiloxane (PDMS) composites thin films, some nickel particles were added into the sensor composite to improve the sensor performance. The piezo-resistive response of CNT composite gives high frequency response in strain measurement, while the ultra-soft PDMS matrix provides high flexibility and ductility for large strain measuring large strain (up to 26%) with an excellent linearity and a fast frequency response under quasi-static test, the delay time for high strain rate test is just 30 μs. This stretchable strain sensor is also able to exhibit much higher sensitivities, with a gauge factor of as high as 80, than conventional foil strain gauges.
Date: May 2016
Creator: Yao, Shulong

Microstructural Phase Evolution In Laser Deposited Compositionally Graded Titanium-Chromium Alloys

Description: A compositionally graded Ti-xCr (10≤x≤30 wt%) alloy has been fabricated using Laser Engineered Net Shaping (LENSTM) to study the microstructural phase evolution along a compositional gradient in both as-deposited and heat treated conditions (1000°C followed by furnace cooling or air cooling). The alloys were characterized by SEM BSE imaging, XRD, EBSD, TEM and micro-hardness measurements to determine processing-structure-property relations. For the as-deposited alloy, α-Ti, β-Ti, and TiCr2 (C15 Laves) phases exist in varying phase fractions, which were influential in determining hardness values. With the furnace cooled alloy, there was more homogeneous nucleation of α phase throughout the sample with a larger phase fraction of TiCr2 resulting in increased hardness values. When compared to the air cooled alloy, there was absence of wide scale nucleation of α phase and formation of ω phase within the β phase due to the quicker cooling from elevated temperature. At lower concentrations of Cr, the kinetics resulted in a diffusionless phase transformation of ω phase with increased hardness and a lower phase fraction of TiCr2. In contrast at higher Cr concentrations, α phase separation reaction occurs where the β phase is spinodally decomposed to Cr solute-lean β1 and solute-rich β2 resulting in reduced hardness.
Date: May 2016
Creator: Thomas, Jonova

Social Anxiety and Non-Medical Prescription Stimulant Use among College Students

Description: Current evidence suggests that non-medical prescription stimulant (NMPS) use is on the rise, particularly among college students. Identifying individuals at risk for regular and problematic use is a critical step towards the development of effective intervention efforts. A growing body of work has noted that individuals with elevated levels of social anxiety (SA) or social anxiety disorder are at an enhanced risk for developing substance use problems, including NMPS use disorder. Despite the relevance of SA and NMPS use among college students, no studies have attempted to examine subclinical SA or the relation between SA and NMPS use among college students specifically. Thus, the present study sought to extend this area by testing the relation of SA symptoms and NMPS use frequency among college students. A large online study of college students was conducted (N=1604) to identify 252 NMPS users (18-25 years; 68.3% female). A hierarchical linear regression was used to test the moderation of positive prescription stimulant expectancies on SA symptoms in predicting past year NMPS use frequency. A subsample of 15 participants was also brought into the lab to assess subjective (State Anxiety) and physiological (salivary cortisol) responding to a social stressor task. Overall, the current study did not provide evidence that SA, via retrospective self-report or real-time responding was related to past year NMPS use frequency. Additional research is needed to resolve the discrepancies between the present findings and prior work.
Date: May 2016
Creator: Cloutier, Renee

Adhesion and Surface Energy Profiles of Large-area Atomic Layers of Two-dimensional MoS2 on Rigid Substrates by Facile Methods

Description: Two-dimensional (2D) transition metal dichalcogenides (TMDs) show great potential for the future electronics, optoelectronics and energy applications. But, the studies unveiling their interactions with the host substrates are sparse and limits their practical use for real device applications. We report the facile nano-scratch method to determine the adhesion energy of the wafer scale MoS2 atomic layers attached to the SiO2/Si and sapphire substrates. The practical adhesion energy of monolayer MoS2 on the SiO2/Si substrate is 7.78 J/m2. The practical adhesion energy was found to be an increasing function of the MoS2 thickness. Unlike SiO2/Si substrates, MoS2 films grown on the sapphire possess higher bonding energy, which is attributed to the defect-free growth and less number of grain boundaries, as well as less stress and strain stored at the interface owing to the similarity of Thermal Expansion Coefficient (TEC) between MoS2 films and sapphire substrate. Furthermore, we calculated the surface free energy of 2D MoS2 by the facile contact angle measurements and Neumann model fitting. A surface free energy ~85.3 mJ/m2 in few layers thick MoS2 manifests the hydrophilic nature of 2D MoS2. The high surface energy of MoS2 helps explain the good bonding strength at MoS2/substrate interface. This simple adhesion energy and surface energy measurement methodology could further apply to other TMDs for their widespread use.
Date: May 2016
Creator: Wu, Min

Predicting Posttraumatic Stress Disorder Symptoms During Adolescence: A Longitudinal Study of The Role of Hypothalamic-Pituitary-Adrenal (HPA) Axis Dysfunction

Description: Posttraumatic stress disorder (PTSD) is a trauma-related disorder that may develop in response to traumatic or stressful events. Dysfunction of the Hypothalamic-Pituitary-Adrenal (HPA) axis has been implicated in the disorder. Studies support such dysfunction as being a consequence of PTSD, rather than a precursor. However, most studies of the HPA are either cross-sectional or have been carried out in adults. The aim of the present study was to identify whether HPA dysregulation interacts with stressful experiences to increase the likelihood of developing PTSD symptoms in a community-recruited sample of healthy adolescent girls. Adolescent girls (N = 550) and one of their parents participated. Adolescents’ clinical symptoms were assessed at baseline and at a nine month follow-up. Saliva samples were collected from all adolescent participants at waking, 30 minutes after waking, and 8 pm on 3 consecutive days. Flattened diurnal slope of cortisol at baseline was associated with increased PTSD symptoms nine months later. Baseline cortisol awakening response (CAR) per se was not prospectively related to developing PTSD symptoms, but its interactions with stressful experience was associated with elevated PTSD symptoms at follow-up. Effects were small and need to be replicated in samples with more severe stressors, as well as more clinical levels of PTSD. Nevertheless, findings suggest that dysregulated basal HPA functioning may be involved in the development of PTSD symptoms.
Date: May 2016
Creator: Liu, Keke

Role of Combat Exposure and Insomnia in Student Veterans' Adaptation to College

Description: Since 2002, the number of veterans enrolled in universities has nearly doubled, although 30-40% of veterans fail to complete their degree. While research efforts to understand the challenges veterans face transitioning from military life to college has increased in recent years, few studies have looked beyond the effects of post-traumatic stress disorder (PTSD). Insomnia is the most frequently reported symptom of combat veterans and can have serious implications for college students. The purpose of this study was to examine the role of insomnia and student veteran adaptation to college relative to civilian students. College students (N = 588) were administered a Background Information Questionnaire, the Insomnia Severity Index, the Deployment Risk and Resilience Inventory, and the Student Adaptation to College Questionnaire. Results revealed that students with insomnia reported significantly lower adaptation to college than students without insomnia. Student veterans reported better academic and personal-emotional adaptation to college than civilian students, while civilians reported better social adjustment than veterans. Although combat veterans without insomnia scored consistently higher academic adjustment than non-combat veterans and civilian students, when present insomnia seemed to have a greater negative effect on combat veterans’ academic adjustment relative to civilian students. Furthermore, insomnia mediated the relationship between combat exposure and veteran’s personal-emotional adjustment to college. Implications and future directions for research are discussed.
Date: May 2016
Creator: McGuffin, James J

Exploring Inorganic Catalysis with Electronic Structure Simulations

Description: Organometallic catalysis has attracted significant interest from both industry and academia due to its wide applications in organic synthetic transformations. Example of such transformations include the reaction of a zinc carbenoid with olefins to form cyclopropanes. The first project is a computational study using both density functional and correlated wavefunction methods of the reaction between ethylene and model zinc carbenoid, nitrenoid and oxenoid complexes (L-Zn-E-X, E = CH2, NH or O, L = X = I or Cl). It was shown that cyclopropanation of ethylene with IZnCH2I and aziridination of ethylene with IZnNHI proceed via a single-step mechanism with an asynchronous transition state. The reaction barrier for the aziridination with IZnNHI is lower than that of cyclopropanation. Changing the leaving group of IZnNHI from I to Cl, changes the mechanism of the aziridination reaction to a two-step pathway. The calculation results from the epoxidation with IZnOI and ClZnOCl oxenoids suggest a two-step mechanism for both oxenoids. Another important example of organometallic catalysis is the formation of alkyl arenes from arenes and olefins using transition metal catalysis (olefin hydroarylation). We studied with DFT methods the mechanism of a novel Rh catalyst (FlDAB)Rh(TFA)(η2–C2H4) [FlDAB = N,N’ -bis(pentafluorophenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene; TFA = trifluoroacetate] that converts benzene, ethylene and air-recyclable Cu(II) oxidants to styrene. Possible mechanisms are discussed.
Date: May 2016
Creator: Karbalaei Khani, Sarah

Evaluating the Pulse Sensor as a Low-Cost and Portable Measurement of Blood Pulse Waveform

Description: This study was aimed at determining whether the digital volume pulse waveform using the Pulse Sensor can be used to extract features related to arterial compliance. The Pulse Sensor, a low-cost photoplethysmograph, measures green light reflection in the finger and generates output, which is indicative of blood flow and can be read by the low-cost Arduino UNO™. The Pulse Sensor code was modified to increase the sampling frequency and to capture the data in a file, which is subsequently used for waveform analysis using programs written in the R system. Waveforms were obtained using the Pulse Sensor during two 30-s periods of seated rest, in each of 44 participants, who were between the ages of 20 and 80 years. For each cardiac cycle, the first four derivatives of the waveform were calculated and low-pass filtered by convolution before every differentiation step. The program was written to extract 19 features from the pulse waveform and its derivatives. These features were selected from those that have been reported to relate to the physiopathology of hemodynamics. Results indicate that subtle features of the pulse waveform can be calculated from the fourth derivative. Feature misidentification occurred in cases of saturation or low voltage and resulted in outliers; therefore, trimmed means of the features were calculated by automatically discarding the outliers. There was a high efficiency of extraction for most features. Significant relationships were found between several of the features and age, and systolic, diastolic, and mean arterial blood pressure, suggesting that these features might be employed to predict arterial compliance. Further improvements in experimental design could lead to a more detailed evaluation of the Pulse Sensor with respect to its capability to predict factors related to arterial compliance.
Date: May 2016
Creator: Smithers, Breana Gray

Developing Policy for a Tech Program Based on Understanding Organizational Practices

Description: This thesis contributes to research that informs the studies of organizational management and organizational anthropology. It examines the internal hierarchy and organizational practices of a Tech Company and describes how findings contributed to policy recommendations aimed towards supporting a “guild” model for organizational success. The data collecting and research were undertaken while working as an employee of the Tech Program and subsequent analysis continued past the end of that phase of work. Methods included semi-structured interviews which captured the sentiments and understandings of employees within the organization, and a questionnaire which revealed sentiments and experiences from former employees. These were buttressed with participant observation engaged through a participatory action research methodology. Findings add to the work directed towards understanding the effect of Founder’s Syndrome within organizations. Additionally, this thesis contributes to a growing body of research centered on best practices for fostering positive organizational growth by creating lines of communication from front-line employees to management level employers.
Date: May 2016
Creator: Machado Perez, Luis Daniel

Learning from small data set for object recognition in mobile platforms.

Description: Did you stand at a door with a bunch of keys and tried to find the right one to unlock the door? Did you hold a flower and wonder the name of it? A need of object recognition could rise anytime and any where in our daily lives. With the development of mobile devices object recognition applications become possible to provide immediate assistance. However, performing complex tasks in even the most advanced mobile platforms still faces great challenges due to the limited computing resources and computing power. In this thesis, we present an object recognition system that resides and executes within a mobile device, which can efficiently extract image features and perform learning and classification. To account for the computing constraint, a novel feature extraction method that minimizes the data size and maintains data consistency is proposed. This system leverages principal component analysis method and is able to update the trained classifier when new examples become available . Our system relieves users from creating a lot of examples and makes it user friendly. The experimental results demonstrate that a learning method trained with a very small number of examples can achieve recognition accuracy above 90% in various acquisition conditions. In addition, the system is able to perform learning efficiently.
Date: May 2016
Creator: Liu, Siyuan

Bioinspired and biocompatible coatings of poly(butylene adipate-co-terephthalate) and layer double hydroxide composites for corrosion resistance

Description: Hierarchical arrangement of biological composites such as nacre and bone containing high filler (ceramic) content results in high strength and toughness of the natural material. In this study we mimic the design of layered bone microstructure and fabricate an optimal multifunctional bio-nanocomposite having strength, toughness and corrosion resistance. Poly (butylene adipate-co-terephthalate) (PBAT), a biodegradable polymer was used as a substrate material with the reinforcement of LDH (Layered double hydroxide) as a nanofiller in different concentrations to achieve enhancement in mechanical properties as well as processing related thermostability. Corrosion resistance was increased by mimicking a layered structured which incorporated a tortuous diffusion path.
Date: May 2016
Creator: Rizvi, Syed Hussain

Surface Topography and Aesthetics of Recycled Cross-Linked Polyethylene Wire and Cable Coatings

Description: Our research focuses on re-using a waste a material, cross-linked polyethylene abbreviated XLPE, which is a widely used coating for wires. XLPE is strong and has excellent thermal properties due to its chemical structure - what leads to the significance of recycling this valuable polymer. Properties of XLPE include good resistance to heat, resistance to chemical corrosion, and high impact strength. A wire is usually composed of a metal core conductor and polymeric coating layers. One creates a new coating, including little pieces of recycled XLPE in the lower layer adjacent to the wire, and virgin XLPE only in the upper layer. Industries are often wasting materials which might be useful. Mostly, some returned or excess products could be recycled to create a new type of product or enable the original use. This method helps cleaning the waste, lowers the costs, and enhances the income of the manufacturing company. With the changing of the thickness of the outer layer, the roughness changes significantly. Moreover, different processing methods result in surfaces that look differently.
Date: December 2014
Creator: Xie, Wa