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  Partner: UNT Libraries
 Degree Level: Master's
 Collection: UNT Theses and Dissertations
Emerging Ed-tech and Accessibility

Emerging Ed-tech and Accessibility

Date: December 2013
Creator: Vora, Disha
Description: Recent developments in the field of education have led to a proliferation of educational technologies (or “ed-tech”), yet access to educational content for students with special needs remains a challenge. This research study aims to assess the current state of accessibility in emerging ed-tech and to identify barriers in enabling educational content to be born accessible. Detailed discussions with various ed-tech platforms revealed less of a need for technical tools, but a more prevailing need for knowledge and education around accessibility – what it means and how best to incorporate accessibility into their platforms. The more experienced teams advocate incorporating accessibility into product development right from the design phase, while the younger teams expressed challenges in navigating accessibility laws and the dire need for easy-to-follow guidelines and best practices. A detailed review of educators' content creation processes reveals multiple dependencies in the ecosystem of ed-tech where partnerships and compatibilities are crucial in enabling accessibility throughout the process. Likewise, an urgent need exists for increasing awareness of accessibility among instructors authoring educational content using emerging ed-tech.
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Multi-year Operation Effect of Geothermal Heat Exchanger on Soil Temperature for Unt Zero Energy Lab

Multi-year Operation Effect of Geothermal Heat Exchanger on Soil Temperature for Unt Zero Energy Lab

Date: December 2013
Creator: Walikar, Vinayak P.
Description: Ground source heat pump (GSHP) uses earth’s heat to heat or cool space. Absorbing heat from earth or rejecting heat to the earth, changes soil’s constant temperature over the multiple years. In this report we have studied about Soil temperature change over multiple years due to Ground loop heat exchanger (GLHE) for Zero Energy Research Laboratory (ZØE) which is located in Discovery Park, University of North Texas, Denton, TX. We did 2D thermal analysis GLHP at particular Depth. For simulation we have used ANSYS workbench for pre-processing and FLUENT ANYS as solver. TAC Vista is software that monitors and controls various systems in ZØE. It also monitors temperature of water inlet/outlet of GLHE. For Monitoring Ground temperatures at various depths we have thermocouples installed till 8ft from earth surface, these temperatures are measured using LabVIEW. From TAC Vista and LabVIEW Reading’s we have studied five parameters in this report using FLUENT ANSYS, they are; (1) Effect of Time on soil Temperature change over Multi-years, (2) Effect of Load on soil temperature change over Multi-years, (3) Effect of Depth on soil temperature change over Multi-years, (4) Effect of Doubling ΔT of inlet and outlet of GLHE on soil temperature change over ...
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Characterization of Viscoelastic Properties of a Material Used for an Additive Manufacturing Method

Characterization of Viscoelastic Properties of a Material Used for an Additive Manufacturing Method

Date: December 2013
Creator: Iqbal, Shaheer
Description: Recent development of additive manufacturing technologies has led to lack of information on the base materials being used. A need arises to know the mechanical behaviors of these base materials so that it can be linked with macroscopic mechanical behaviors of 3D network structures manufactured from the 3D printer. The main objectives of my research are to characterize properties of a material for an additive manufacturing method (commonly referred to as 3D printing). Also, to model viscoelastic properties of Procast material that is obtained from 3D printer. For this purpose, a 3D CAD model is made using ProE and 3D printed using Projet HD3500. Series of uniaxial tensile tests, creep tests, and dynamic mechanical analysis are carried out to obtained viscoelastic behavior of Procast. Test data is fitted using various linear and nonlinear viscoelastic models. Validation of model is also carried out using tensile test data and frequency sweep data. Various other mechanical characterization have also been carried out in order to find density, melting temperature, glass transition temperature, and strain rate dependent elastic modulus of Procast material. It can be concluded that melting temperature of Procast material is around 337°C, the elastic modulus is around 0.7-0.8 GPa, and yield ...
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Immunohistochemistry of the Gills of the Channel Catfish Ictalurus Punctatus: Cells and Neurochemicals That May Be Involved in the Control of Cardioventilatory Reflexes

Immunohistochemistry of the Gills of the Channel Catfish Ictalurus Punctatus: Cells and Neurochemicals That May Be Involved in the Control of Cardioventilatory Reflexes

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Date: December 2013
Creator: Oden, David S.
Description: In teleost fishes the neurochemicals involved in sensing and responding to hypoxia are unresolved. Serotonergic branchial neuroepithelial cells (NECs) are putative O2 chemoreceptors believed to be homologous to the neural crest (NC) derived APUD (amine-precursor uptake and decarboxylation) pulmonary NECs and carotid body type-1 glomus cells. Branchial NECs contain serotonin (5-HT), thought to be central to the induction of the hypoxic cardioventilatory reflexes. However, application of 5-HT in vivo does not elicit cardioventilatory reflexes similar to those elicited by hypoxia. But previous in vitro neural recordings from glossopharyngeal (IX) afferents innervating O2 chemoreceptors in the trout gill show the same discharge response to hypoxic conditions as does that of acetylcholine (ACh) application. This evidence strongly supports the cholinergic hypothesis of chemoreceptor impulse origin rather than a serotonergic-induced impulse origin model. We therefore hypothesized that NECs contain ACh among other neurochemicals in cells belonging to the APUD series. Although serotonergic branchial NECs did not colocalize with ACh using immunohistochemical methods, several populations of ACh and/or tyrosine hydroxylase (TH) (catecholaminergic) positive, dopamine (DA) negative, cells were found throughout the second gill arch of the channel catfish Ictalurus punctatus. In addition, the NC derivation marker zn-12 labelled the HNK-1-like epitope (Human natural killer) ...
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The Measurement of the Third-order Elastic Constants for La3ga5sio14 (Lgs) and La3ga55ta05o14 (Lgt) Single Crystal

The Measurement of the Third-order Elastic Constants for La3ga5sio14 (Lgs) and La3ga55ta05o14 (Lgt) Single Crystal

Date: December 2013
Creator: Karim, Md Afzalul
Description: Recently, the development of electronic technology towards higher frequencies and larger band widths has led to interest in finding new piezoelectric materials, which could be used to make filters with larger pass band widths and oscillators with better frequency stability. Langasite (La3Ga5SiO14, LGS) and its isomorphs have enticed considerable attention of researchers as a potential substrate material for piezoelectric device applications because of its high frequency stability and fairly good electromechanical coupling factors for acoustic wave devices. Nonlinear effect including drive level dependence, mode coupling, force-frequency effect and electroelasic effect are critical for the design of these devices. Third-order elastic constants (TOEC) play an important role in a quantitative analysis of these nonlinear effects. In particular these elastic constants are of great importance when the BAW (Bulk Acoustic Wave) and SAW (Surface Acoustic Wave) sensors of force, acceleration and so on are designed. Until now Langasite (LGS) and Langatate (LGT) crystal resonators have been qualified in terms of quality factor, temperature effect, isochronism defect and material quality. One of the most important advantages of those crystals is that they will not undergo phase transitions up to its melting temperature of 1450°. Presently there is no data on TOEC of LGT ...
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Tribological Behavior of Spark Plasma Sintered Tic/graphite/nickel Composites and Cobalt Alloys

Tribological Behavior of Spark Plasma Sintered Tic/graphite/nickel Composites and Cobalt Alloys

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Date: December 2013
Creator: Kinkenon, Douglas
Description: Monolithic composites are needed that combine low friction and wear, high mechanical hardness, and high fracture toughness. Thin films and coatings are often unable to meet this engineering challenge as they can delaminate and fracture during operation ceasing to provide beneficial properties during service life. Two material systems were synthesized by spark plasma sintering (SPS) and were studied for their ability to meet these criteria. A dual hybrid composite was fabricated and consisted of a nickel matrix for fracture toughness, TiC for hardness and graphite for solid/self‐lubrication. An in‐situ reaction during processing resulted in the formation of TiC from elemental Ti and C powders. The composition was varied to determine its effects on tribological behavior. Stellite 21, a cobalt‐chrome‐molybdenum alloy, was also produced by SPS. Stellite 21 has low stacking fault energy and a hexagonal phase which forms during sliding that both contribute to low interfacial shear and friction. Samples were investigated by x‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x‐ray spectroscopy (EDS), and electron back‐scattered diffraction (EBSD). Tribological properties were characterized by pin on disc tribometry and wear rates were determined by profilometry and abrasion testing. Solid/self‐lubrication in the TiC/C/Ni system was investigated by Raman and Auger ...
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A Comprehensive Modeling Framework for Airborne Mobility

A Comprehensive Modeling Framework for Airborne Mobility

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Date: December 2013
Creator: Xie, Junfei
Description: Mobility models serve as the foundation for evaluating and designing airborne networks. Due to the significant impact of mobility models on the network performance, mobility models for airborne networks (ANs) must realistically capture the attributes of ANs. In this paper, I develop a comprehensive modeling framework for ANs. The work I have done is concluded as the following three parts. First, I perform a comprehensive and comparative analysis of AN mobility models and evaluate the models based on several metrics: 1) networking performance, 2) ability to capture the mobility attributes of ANs, 3) randomness levels and 4) associated applications. Second, I develop two 3D mobility models and realistic boundary models. The mobility models follow physical laws behind aircraft maneuvering and therefore capture the characteristics of aircraft trajectories. Third, I suggest an estimation procedure to extract parameters in one of the models that I developed from real flight test data. The good match between the estimated trajectories and real flight trajectories also validate the suitability of the model. The mobility models and the estimation procedure lead to the creation of “realistic” simulation and evaluation environment for airborne networks.
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A Textual Analysis of the Closer and Saving Grace: Feminist and Genre Theory in 21St Century Television

A Textual Analysis of the Closer and Saving Grace: Feminist and Genre Theory in 21St Century Television

Date: December 2013
Creator: Stone, Lelia M.
Description: Television is a universally popular medium that offers a myriad of choices to viewers around the world. American programs both reflect and influence the culture of the times. Two dramatic series, The Closer and Saving Grace, were presented on the same cable network and shared genre and design. Both featured female police detectives and demonstrated an acute awareness of postmodern feminism. The Closer was very successful, yet Saving Grace, was cancelled midway through the third season. A close study of plot lines and character development in the shows will elucidate their fundamental differences that serve to explain their widely disparate reception by the viewing public.
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Shortened in Vivo Bioconcentration Factor Testing in Cyprinus Carpio

Shortened in Vivo Bioconcentration Factor Testing in Cyprinus Carpio

Date: December 2013
Creator: Cantu, Mark
Description: Bioconcentration factor testing serves as the most valuable surrogate for the assessment of bioaccumulation. The assessment of potentially harmful chemicals is crucial to not only the health of aquatic environments, but to humans as well. Chemicals that possess the ability to persist in the environment or that have the potential to bioaccumulate, pose a greater risk to organisms that are exposed to these chemicals. The Organization for Economic Cooperation and Development Guideline 305 outlines specific protocols to run an accurate and reliable aquatic flow-through test. However, since its adoption in 1996, very few changes have been made to accommodate the endeavor to lowering the amount of test species to run one of these said tests. Running an aquatic flow-through test, according to 305, takes much time and money as well as numerous amounts of fish. Such burdens can be eliminated through simple modifications to the standard protocols. In this study, we propose an abbreviated study design for aquatic bioconcentration testing which effectively alleviates the burdens of running a flow-through test. Four chemicals were used individually to evaluate the usefulness of the proposed shortened design; 4-Nonyphenol, Chlorpyrifos, Musk Xylene, and DDT. The study consisted of exposing Cyprinus carpio for 7 days ...
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The Acute Hormonal Response to the Kettlebell Swing Exercise

The Acute Hormonal Response to the Kettlebell Swing Exercise

Date: December 2013
Creator: Budnar Jr., Ronald Gene
Description: The purpose of this investigation was to examine the acute hormonal response to a bout of kettlebell swing exercise. Ten healthy men (19-30 y, 23.6 ± 3.5 y, 174.6 ± 5.7 cm, 78.7 ± 9.9 kg) who were engaged in resistance training at least twice per week but were inexperienced with kettlebell swings participated in this study. Participants were familiarized with the kettlebell swing exercise during an initial visit. During the subsequent experimental protocol visit, participants performed 12 rounds of 30 seconds of 16-kg kettlebell swings alternated with 30 seconds of rest. Heart rate (HR) and rating of perceived exertion (RPE) were measured at the end of every round of swings. Fasted blood samples were collected pre-exercise (PRE), immediately post (IP), 15 minutes post (P15), and 30 minutes post exercise (P30) and analyzed for total testosterone (T), growth hormone (GH), cortisol, and lactate concentrations. Participants completed a total of 227 ± 23 swings (average swings per round: 19 ± 2). HR and RPE increased significantly (P < 0.05) throughout the exercise protocol. Lactate concentrations were significantly increased at all post exercise time points compared to PRE. T was significantly increased at IP compared to PRE. GH was significantly increased at ...
Contributing Partner: UNT Libraries
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