239 Matching Results

Results open in a new window/tab.

Interfacial Characterization of Chemical Vapor Deposition (Cvd) Grown Graphene and Electrodeposited Bismuth on Ruthenium Surface (open access)

Interfacial Characterization of Chemical Vapor Deposition (Cvd) Grown Graphene and Electrodeposited Bismuth on Ruthenium Surface

Graphene receives enormous attention owing to its distinctive physical and chemical prosperities. Growing and transferring graphene to different substrates have been investigated. The graphene growing on the copper substrate has an advantage of low solubility of carbon on the copper which allow us to grow mostly monolayer graphene. Graphene sheet of few centimeters can be transferred to 300nm silicon oxide and quartz crystal pre-deposited with metal like Cu and Ru. Characterization of the graphene has been done with Raman and contact angle measurement and recently quartz crystal microbalance (QCM) has been employed. The underpotential deposition (UPD) process of Bi on Ru metal surface is studied using electrochemical quartz crystal microbalance (EQCM) and XPS techniques. Both Bi UPD and Bi bulk deposition are clearly observed on Ru in 1mM Bi (NO3)3/0.5M H2SO4. Bi monolayer coverage calculated from mass (MLMass) and from charge (MLCharge) were compared with respect to the potential scanning rates, anions and ambient controls. EQCM results indicate that Bi UPD on Ru is mostly scan rate independent but exhibits interesting difference at the slower scan. Bi UPD monolayer coverage calculated from cathodic frequency change (ΔfCathodic) is significantly smaller than the monolayer coverage derived from integrated charge under the cathodic …
Date: May 2014
Creator: Abdelghani, Jafar
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Source Apportionment Analysis of Measured Volatile Organic Compounds in Corpus Christi, Texas (open access)

Source Apportionment Analysis of Measured Volatile Organic Compounds in Corpus Christi, Texas

Corpus Christi among of the largest industrialized coastal urban areas in Texas. The strategic location of the city along the Gulf of Mexico allows for many important industries and an international business to be located. The cluster of industries and businesses in the region contribute to the air pollution from emissions that are harmful to the environment and to the people living in and visiting the area. Volatile organic compounds (VOC) constitute an important class of pollutants measured in the area. The automated gas chromatography (Auto GC) data was collected from Texas Commission of Environmental Quality (TCEQ) and source apportionment analysis was conducted on this data to identify key sources of VOC affecting this study region. EPA PMF 3.0 was employed in this sources apportionment study of measured VOC concentration during 2005 - 2012 in Corpus Christi, Texas. The study identified nine optimal factors (Source) that could explain the concentration of VOC at two urbane monitoring sites in the study region. Natural gas was found to be the largest contributor of VOC in the area, followed by gasoline and vehicular exhaust. Diesel was the third highest contributor with emissions from manufacturing and combustion processes. Refineries gases and evaporative fugitive emissions …
Date: May 2014
Creator: Abood, Ahmed T.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Development of a Cost Effective Wireless Sensor System for Indoor Air Quality Monitoring Applications (open access)

Development of a Cost Effective Wireless Sensor System for Indoor Air Quality Monitoring Applications

Poor air quality can greatly affect the public health. Research studies indicate that indoor air can be more polluted than the outdoor air. An indoor air quality monitoring system will help to create an awareness of the quality of air inside which will eventually help in improving it. The objective of this research is to develop a low cost wireless sensor system for indoor air quality monitoring. The major cost reduction of the system is achieved by using low priced sensors. Interface circuits had to be designed to make these sensors more accurate. The system is capable of measuring carbon dioxide, carbon monoxide, ozone, temperature, humidity and volatile organic compounds. The prototype sensor node modules were developed. The sensor nodes were the connected together by Zigbee network. The nodes were developed in such a way that it is compact in size and wireless connection of sensor nodes enable to collect air quality data from multiple locations simultaneously. The collected data was stored in a computer. We employed linear least-square approach for the calibration of each sensor to derive a conversion formula for converting the sensor readings to engineering units. The system was tested with different pollutants and data collected was …
Date: May 2014
Creator: Abraham, Sherin
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Exploratory Analysis of Social E-health Behavior (open access)

Exploratory Analysis of Social E-health Behavior

Extant literature has documented well that people seek health information via the internet as patients and consumers. Much less, however, is known about interaction and creation behaviors in the development of new online health information and knowledge. More specifically, generalizable sociodemographic data on who engages in this online health behavior via social media is lacking in the sociological literature. The term “social e-health” is introduced to emphasize the difference between seeking behaviors and interaction and creation behaviors. A 2010 dataset of a large nationally representative and randomly sampled telephone survey made freely available from the Pew Research Center is used to examine social e-health behavior according to respondents’ sociodemographics. The dependent variable of social e-health behavior is measured by 13 survey questions from the survey. Gender, race, ethnicity, age, education, and income are used as independent variables. Logistic regression analysis was used to determine the odds of engagement in social e-health behavior based on the sociodemographic predictors. The social determinants of health and digital divide frameworks are used to help explain why socioeconomic variances exist in social e-health behavior. The findings of the current study suggest that predictable sociodemographic patterns along the dimensions of gender, race, age, education, and income …
Date: May 2014
Creator: Acadia, Spencer
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Family Structure and Marijuana Use Among Adolescents (open access)

Family Structure and Marijuana Use Among Adolescents

Family structure as a predictive variable of juvenile delinquency has been studied for the last hundred years. This relationship originated due to societal belief that divorce was detrimental to adolescents. Due to the changing societal roles in the United States, family structure has been changing. More children are growing up in non-intact families, such as single-parent households, households with stepparents, cohabitating families, and households without a parent present. To study the effect family structure has on juvenile delinquency, researchers have utilized social control theory, differential association, self-control theory and general strain theory to conceptualize variables to explain why family structure influences delinquent behavior. A review of previous literature on this topic indicates that living in intact households, which are households with two biological parents who are married, have, on average, the lowest rates of delinquency. This thesis investigates the relationship between family structure and lifetime marijuana use among eighth and tenth grade adolescents in the United States through the use of secondary data analysis of Monitoring the Future Study, 2012. The results provide support for the relationship between family structure and lifetime marijuana use.
Date: May 2014
Creator: Aguilar, Jamie M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Low Leakage Asymmetric Stacked Sram Cell (open access)

Low Leakage Asymmetric Stacked Sram Cell

Memory is an important part of any digital processing system. On-chip SRAM can be found in various levels of the memory hierarchy in a processor and occupies a considerable area of the chip. Leakage is one of the challenges which shrinking of technology has introduced and the leakage of SRAM constitutes a substantial part of the total leakage power of the chip due to its large area and the fact that many of the cells are idle without any access. In this thesis, we introduce asymmetric SRAM cells using stacked transistors which reduce the leakage up to 26% while increasing the delay of the cell by only 1.2% while reducing the read noise margin of the cell by only 15.7%. We also investigate an asymmetric cell configuration in which increases the delay by 33% while reduces the leakage up to 30% and reducing the read noise margin by only 1.2% compared to a regular SRAM cell.
Date: May 2014
Creator: Ahrabi, Nina
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Space in Space: Privacy Needs for Long-Duration Spaceflight (open access)

Space in Space: Privacy Needs for Long-Duration Spaceflight

Space exploration is a uniquely human activity. As humans continue to push the limits of exploring the unknown, they have sought knowledge supporting the sustenance of life in outer space. New technologies, advancements in medicine, and rethinking what it means to be a “community” will need to emerge to support life among the stars. Crews traveling beyond the Moon will rely on the development of new technologies to support the technological aspects of their missions as well as their quality of life while away from Earth. Likewise, through advancements in medicine, scientists will need to address remaining questions regarding the effects of long-duration spaceflight on the human body and crew performance. Space explorers must learn to utilize these new technologies and medical advancements while learning to adapt to their new environment in space and as a space community. It is important that researchers address these issues so that human survival beyond Earth is not only achievable but so that life among the stars is worth living and sustaining. This thesis addressed these issues in an attempt to extend the trajectory of space exploration to new horizons.
Date: May 2014
Creator: Aiken, Jo
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The Use of Social Media in Informal Scientific Communication Among Scholars: Modeling the Modern Invisible College (open access)

The Use of Social Media in Informal Scientific Communication Among Scholars: Modeling the Modern Invisible College

The concept of the invisible college is a key focus of scientific communication research with many studies on this topic in the literature. However, while such studies have contributed to an understanding of the invisible college, they have not adequately explained the interaction of social and structural processes in this phenomenon. As a consequence, past research has described the invisible college differently based on researchers’ perspectives, resulting in misinterpretations or inconsistent definitions of the relevant social and structural processes. Information science and related disciplines have focused on the structural processes that lead to scholarly products or works while placing less emphasis on the social processes. To advance understanding of the invisible college and its dimensions (including both social processes and structural processes), a proposed model (Modern Invisible College Model, MICM) has been built based on the history of the invisible college and Lievrouw’s (1989) distinction between social and structural processes. The present study focuses on the social processes of informal communication between scholars via social media, rather than on the structural processes that lead to scholarly products or works. A developed survey and an employed quantitative research method were applied for data collection. The research population involved 77 scholars from …
Date: May 2014
Creator: Algarni, Mohammed Ayedh
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Nuestra Voz De North Texas (Fort Worth, Tex.), Vol. 1, No. 7, Ed. 1, May/June 2014 (open access)

Nuestra Voz De North Texas (Fort Worth, Tex.), Vol. 1, No. 7, Ed. 1, May/June 2014

Newspaper providing news and information to the Tarrant and Dallas County Latino communities along with advertising.
Date: May 2014
Creator: Alvarado, Felix
Object Type: Newspaper
System: The Portal to Texas History
Thematic and Formal Narrative in Respighi’s Sinfonia Drammatica (open access)

Thematic and Formal Narrative in Respighi’s Sinfonia Drammatica

Respighi’s scarcely-known orchestral work Sinfonia Drammatica lives up to its title by evoking a narrative throughout the course of its three movements. In this dissertation, I argue how the work’s surface, subsurface, and formal elements suggest this narrative which emerges as a cycle of rising and falling dramatic tension. I explain how Respighi constructs the work’s narrative in the musical surface through a diverse body of themes that employ three motives of contour. The disposition and manipulation of these motives within the themes suggest frequent fluctuations of the level of conflict throughout the symphony as a whole. To show the involvement of musical forms in the work’s narrative, I employ an approach which integrates harmony and thematic behavior. I utilize analytical methods from the current Formenlehre, including terms from James Hepokoski and Warren Darcy’s sonata deformation theory and William Caplin’s theories of formal functions to elucidate ties between the forms of the Sinfonia Drammatica’s movements and those of conventional sonata forms of the late-eighteenth century. This dissertation also employs Heinrich Schenker’s theories of structures, voice leading, and reduction to illustrate large-scale aspects of the Sinfonia Drammatica’s narrative. The resulting analyses show Respighi’s elaborations of common structural paradigms which serve to …
Date: May 2014
Creator: Amato, Alexander G.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Southwest Retort, Volume 66, Number 9, May 2014 (open access)

Southwest Retort, Volume 66, Number 9, May 2014

This publication of the Dallas-Fort Worth Section of the American Chemical Society includes information about research, prominent scientist, organizational business, and various other stories of interest to the community.
Date: May 2014
Creator: American Chemical Society. Dallas/Fort Worth Section.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Consumer Shopping Motivations with Facebook Retailers: Utilitarian Versus Hedonic (open access)

Consumer Shopping Motivations with Facebook Retailers: Utilitarian Versus Hedonic

Retailers increasingly are connecting with consumers using social media. This two-way, networked communication method facilitates word-of-mouth that may ultimately impact retailer loyalty. The purpose of this study was to examine motivations of consumers’ purchase intention from apparel Facebook retailers, and the relationship between purchase intention and loyalty. Consumer motivations were examined in terms of the utilitarian values of cost, convenience, and information and the hedonic values of experiential shopping, bargain perception, sociability, and curiosity. The relationship of purchase intention and loyalty also was investigated. The instrument was developed from existing scales drawn from literature. A consumer panel (N = 250) of Facebook users that connect to apparel retailers was used to collect data through an online Qualtrics survey. Statistical analysis included descriptive statistics of frequency and crosstab distributions, factor analysis, and regression analysis. Factor analysis resulted in four dimensions including convenience, information, experience, and bargains. All motivators were found to be significantly related to both purchase intention and loyalty for this consumer group. The variable with the strongest relationship to both purchase intention and loyalty was experience. Additionally, a strong relationship was found between purchase intention and loyalty. Lastly, practical business implications are reviewed, in addition to limitations of the …
Date: May 2014
Creator: Anderson, Kelley B.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Shall We Dance? Teaching Parents the Communication Dance to Enhance Generalized Communication in Their Children (open access)

Shall We Dance? Teaching Parents the Communication Dance to Enhance Generalized Communication in Their Children

Children diagnosed with autism exhibit deficits in communication that impact their ability to control their immediate environment. Recent research on mand training has been criticized for producing a limited number of mand topographies over a long span of time with limited generalization to novel environments. There is a body of research, however, that successfully establishes larger repertoires. Training parents as change agents may mediate generalization by teaching under naturally maintaining contingencies. Additional effects of parent training may reduce parent reports of stress, increase favorable quality of parent-child interactions, and increase reports of parental self-efficacy. The current study evaluated the effects of a generalized training framework to teach parents how to target generalized mands and expand their child’s communicative topographies. The effects of the training were evaluated using a non-concurrent multiple baseline across participants and skills. Results indicated that parents were able to effectively teach their child to mand for a variety of items and events and to substantially increase the number of different mand topographies and expand the topographies the child emitted. Parents were observed to have higher overall confidence and lower overall stress following intervention. The current study builds on previous research on generalized teaching strategies for parents that …
Date: May 2014
Creator: Baker, Jacqueline R.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Philosophy and an Approach to Teaching Non-professional-track Violin Students (open access)

A Philosophy and an Approach to Teaching Non-professional-track Violin Students

The aim of this dissertation is to lay the groundwork for an integrated approach to violin instruction for children who are not being groomed explicitly for professional careers as instrumentalists. The study presents a particular focus on the age of middle school children, in order to showcase a more specialized and definitive result of research without, however, distinguishing between advantages and limitations of different age groups of children who study music and learn to play the violin. My first goal is to craft a sample method of teaching with a premise that not all students studying music must or need to become professional musicians in their future. I promote an approach based on the premise that music has universal value available to all and that any kind of music education encourages the growth, personality development, and imagination of children. My second goal is to explore how music education functions in 21st century western culture. Research is based on teachings and methods established by Suzuki, Kodaly, Jaques-Dalcroze, and Orff, among others.
Date: May 2014
Creator: Bard-Schwarz, Anna Ewa
Object Type: Thesis or Dissertation
System: The UNT Digital Library

One Bookmark to Rule Them All: How the use of a bookmark linked to the Librarian's LibGuides profile can empower research and serve the instructional materials needs of the Librarian

Poster presented at the Art Libraries Society of North America Annual Conference. This poster discusses how the use of a bookmark linked to the Librarian's LibGuides profile can empower research and serve the instructional materials needs of the Librarian.
Date: May 3, 2014
Creator: Barham, Rebecca
Object Type: Poster
System: The UNT Digital Library
The Efficacy of the Chickasaw Nation Early Care and Education Programs (open access)

The Efficacy of the Chickasaw Nation Early Care and Education Programs

The purposes of this research were to explore the effectiveness of the Chickasaw Nation early care and education program in promoting school readiness while infusing tribally relevant values in children from birth through age five; engaging parents in all aspects of their children’s learning; and supporting children and families through the transitioning to kindergarten. The study used qualitative methods to examine the experiences and perceptions of ten parents, ten teachers, and five administrators within Chickasaw Nation’s early care and education system regarding the four basic areas of school readiness, parent engagement, transition, and culturally relevant pedagogy. Four primary themes emerged from the semi-structured interviews: 1) socialization, school readiness, and transition, 2) learning, curriculum, and assessment, 3) the role of parents, and 4) cultural integrity. Data were collected through semi-structured interviews, transcribed, and analyzed based on four research questions. Findings indicated parents, teachers, and administrators were satisfied that the program was successful with assisting children in making progress toward achieving developmental and school readiness goals and that the children were physically, socially, emotionally, and cognitively prepared to enter kindergarten. The program provided activities to encourage and promote parental involvement; however, parents did not indicate active involvement or participation in the activities. …
Date: May 2014
Creator: Blackmon, Lisa
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Processing and Characterization of Nickel-Carbon Base Metal Matrix Composites (open access)

Processing and Characterization of Nickel-Carbon Base Metal Matrix Composites

Carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) are attractive reinforcements for lightweight and high strength metal matrix composites due to their excellent mechanical and physical properties. The present work is an attempt towards investigating the effect of CNT and GNP reinforcements on the mechanical properties of nickel matrix composites. The CNT/Ni (dry milled) nanocomposites exhibiting a tensile yield strength of 350 MPa (about two times that of SPS processed monolithic nickel ~ 160 MPa) and an elongation to failure ~ 30%. In contrast, CNT/Ni (molecular level mixed) exhibited substantially higher tensile yield strength (~ 690 MPa) but limited ductility with an elongation to failure ~ 8%. The Ni-1vol%GNP (dry milled) nanocomposite exhibited the best balance of properties in terms of strength and ductility. The enhancement in the tensile strength (i.e. 370 MPa) and substantial ductility (~40%) of Ni-1vol%GNP nanocomposites was achieved due to the combined effects of grain refinement, homogeneous dispersion of GNPs in the nickel matrix, and well-bonded Ni-GNP interface, which effectively transfers stress across metal-GNP interface during tensile deformation. A second emphasis of this work was on the detailed 3D microstructural characterization of a new class of Ni-Ti-C based metal matrix composites, developed using the laser engineered net …
Date: May 2014
Creator: Borkar, Tushar Murlidhar
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Texas Principals’ Data Use: Its Relationship to Leadership Style and Student Achievement (open access)

Texas Principals’ Data Use: Its Relationship to Leadership Style and Student Achievement

This study applies an empirical research method determine whether Texas public school principals’ leadership styles, coupled with their use of real time data in a data warehouse, influenced their leadership ability as measured by student achievement. In today’s world of data rich environments that require campuses and districts to make data-driven decisions, principals find themselves having to organize and categorize data to help their school boards, campuses, and citizenry make informed decisions. Most school principals in Texas have access to data in multiple forms including national and state resources and a multitude of other data reports. A random sample of principals was selected to take the Multi Factor Leadership Questionnaire (MLQ5x) and the Principals Data Use Survey. The MLQ5x measured principals’ leadership styles as transformational, transactional, or passive avoidant. The Principals Data Use Survey measured how principals use data to inform campus decisions on student achievement, shaping the vision of the campus, and designing professional development. Data obtained from the survey were correlated to determine the relationship between principals’ use of data warehouses and their leadership styles on student achievement as measured by the Texas Assessment of Knowledge and Skills. The results yielded significant relationships between student achievement, principals’ leadership …
Date: May 2014
Creator: Bostic, Robert E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Physiological and Psychological Effects of an Acute Stressor: Comparing Coping Strategies Among Very Physically Active and Less Active Adults (open access)

Physiological and Psychological Effects of an Acute Stressor: Comparing Coping Strategies Among Very Physically Active and Less Active Adults

The purpose of this study was to examine whether physical activity status of healthy adult males (N = 59) while in a coping strategy condition (association, disassociation, or control) influences psychophysiological responses to an acute painful stimulus. Measures of pain tolerance, state anxiety, body awareness, and salivary cortisol were investigated. Results indicated no significant differences between physical activity groups for pain tolerance, stress responses (i.e., self-reported state anxiety and cortisol levels), or body awareness. Though, those who indicated using a disassociation coping technique during the exit interview tolerated the acute, surface pain longer. More research is required to further understand the effects of physical activity and coping strategies on pain perception and psychophysiological responses.
Date: May 2014
Creator: Brandt, Grace A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 40, Ed. 1 Thursday, May 1, 2014 (open access)

Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 40, Ed. 1 Thursday, May 1, 2014

Weekly newspaper from Mount Vernon, Texas that includes local, state and national news along with advertising.
Date: May 1, 2014
Creator: Bush-Reves, Lillie
Object Type: Newspaper
System: The Portal to Texas History
Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 41, Ed. 1 Thursday, May 8, 2014 (open access)

Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 41, Ed. 1 Thursday, May 8, 2014

Weekly newspaper from Mount Vernon, Texas that includes local, state and national news along with advertising.
Date: May 8, 2014
Creator: Bush-Reves, Lillie
Object Type: Newspaper
System: The Portal to Texas History
Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 42, Ed. 1 Thursday, May 15, 2014 (open access)

Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 42, Ed. 1 Thursday, May 15, 2014

Weekly newspaper from Mount Vernon, Texas that includes local, state and national news along with advertising.
Date: May 15, 2014
Creator: Bush-Reves, Lillie
Object Type: Newspaper
System: The Portal to Texas History
Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 43, Ed. 1 Thursday, May 22, 2014 (open access)

Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 43, Ed. 1 Thursday, May 22, 2014

Weekly newspaper from Mount Vernon, Texas that includes local, state and national news along with advertising.
Date: May 22, 2014
Creator: Bush-Reves, Lillie
Object Type: Newspaper
System: The Portal to Texas History
Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 44, Ed. 1 Thursday, May 29, 2014 (open access)

Mount Vernon Optic-Herald (Mount Vernon, Tex.), Vol. 140, No. 44, Ed. 1 Thursday, May 29, 2014

Weekly newspaper from Mount Vernon, Texas that includes local, state and national news along with advertising.
Date: May 29, 2014
Creator: Bush-Reves, Lillie
Object Type: Newspaper
System: The Portal to Texas History