UNT Libraries - 4,301 Matching Results

Search Results

prev Results: 891 - 914 next
open access

Design of Voltage Boosting Rectifiers for Wireless Power Transfer Systems

Description: This thesis presents a multi-stage rectifier for wireless power transfer in biomedical implant systems. The rectifier is built using Schottky diodes. The design has been simulated in 0.5µm and 130nm CMOS processes. The challenges for a rectifier in a wireless power transfer systems are observed to be the efficiency, output voltage yield, operating frequency range and the minimum input voltage the rectifier can convert. The rectifier outperformed the contemporary works in the mentioned criteria.
Date: May 2019
Creator: Suri, Ramaa Saket
open access

Design Principle on Carbon Nanomaterials Electrocatalysts for Energy Storage and Conversion

Description: We are facing an energy crisis because of the limitation of the fossil fuel and the pollution caused by burning it. Clean energy technologies, such as fuel cells and metal-air batteries, are studied extensively because of this high efficiency and less pollution. Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are essential in the process of energy storage and conversion, and noble metals (e.g. Pt) are needed to catalyze the critical chemical reactions in these devices. Funct… more
Date: May 2017
Creator: Zhao, Zhenghang
open access

Design Principles for Metal-Coordinated Frameworks as Electrocatalysts for Energy Storage and Conversion

Description: In this dissertation, density functional theory calculations are performed to calculate the thermodynamic and electrochemical properties of metal coordinated frameworks for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Gibb's free energy, overpotential, charge transfer and ligands effect are evaluated. The charge transfer analysis shows the positive charges on the metal coordinated frameworks play an essential role in improving the electrochemical properties of the metal … more
Date: December 2018
Creator: Lin, Chun-Yu
open access

Design Space Exploration of Domain Specific CGRAs Using Crowd-sourcing

Description: CGRAs (coarse grained reconfigurable array architectures) try to fill the gap between FPGAs and ASICs. Over three decades, the research towards CGRA design has produced number of architectures. Each of these designs lie at different points on a line drawn between FPGAs and ASICs, depending on the tradeoffs and design choices made during the design of architectures. Thus, design space exploration (DSE) takes a very important role in the circuit design process. In this work I propose the design spa… more
Date: August 2014
Creator: Sistla, Anil Kumar
open access

Design, Synthesis, and Characterization of Aqueous Polymeric Hybrid Composites and Nanomaterials of Platinum(II) and Gold(I) Phosphorescent Complexes for Sensing and Biomedical Applications

Description: The two major topics studied in this dissertation are the gold(I) pyrazolate trimer {[Au(3-R,5-R’)Pz]3} complexes in aqueous chitosan polymer and phosphorescent polymeric nanoparticles based on platinum(II) based complex. The first topic is the synthesis, characterization and optical sensing application of gold(I) pyrazolate trimer complexes within aqueous chitosan polymer. A gold(I) pyrazolate trimer complex, {[Au(3-CH3,5-COOH)Pz]3}, shows high sensitivity and selectivity for silver ions in aq… more
Date: December 2015
Creator: Upadhyay, Prabhat Kumar

Design, Synthesis and Characterization of Polymer and Protein Coated Hybrid Nanomaterials: Investigation of Prototypes for Antimicrobial and Anticancer Applications

Description: This work involves synthesis and characterization of isotropic and anisotropic noble metal nanoparticles for applications ranging from antimicrobial uses to anticancer applications. These nanomaterials are stabilized in genuinely benign biomaterials ranging from polymers to cross linked proteins for targeted cancer treatments. The nanoparticles are found to have tunable optical properties.
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: May 2019
Creator: Korir, Daniel Kiplangat
open access

Design, Synthesis and Optoelectronic Properties of Monovalent Coinage Metal-Based Functional Materials toward Potential Lighting, Display and Energy-Harvesting Devices

Description: Groundbreaking progress in molecule-based optoelectronic devices for lighting, display and energy-harvesting technologies demands highly efficient and easily processable functional materials with tunable properties governed by their molecular/supramolecular structure variations. To date, functional coordination compounds whose function is governed by non-covalent weak forces (e.g., metallophilic, dπ-acid/dπ-base stacking, halogen/halogen and/or d/π interactions) remain limited. This is unlike t… more
Date: August 2017
Creator: Ghimire, Mukunda Mani
open access

Design, Synthesis and Screening of Homoleptic and Heteroleptic Platinum(ii) Pyridylazolate Complexes for N-type Semiconducting and Light-emitting Devices

Description: A series of heteroleptic and homoleptic platinum(II) complexes has been synthesized and characterized towards their use in thin film devices such as organic light-emitting diodes (OLEDs) and organic thin film transistors (OTFTs). Pyridylpyrazolate- and pyridyltetrazolate-containing ligands were selected due to their structural rigidity and ease of functionalization. Single-crystal x-ray diffraction studies of two selected heteroleptic complexes show strong aggregation with preferential stacking… more
Date: August 2012
Creator: Oswald, Iain William Herbert
open access

Design, Synthesis and Study of Supramolecular Donor – Acceptor Systems Mimicking Natural Photosynthesis Processes

Description: This dissertation investigates the chemical ingenuity into the development of various photoactive supramolecular donor – acceptor systems to produce clean and carbon free energy for the next generation. The process is inspired by the principles learned from nature’s approach where the solar energy is converted into the chemical energy through the natural photosynthesis process. Owing to the importance and complexity of natural photosynthesis process, we have designed ideal donor-acceptor system… more
Date: December 2015
Creator: KC, Chandra Bikram
open access

Designing Tools to Probe the Calcium-dependent Function of Arabidopsis Tonneau2

Description: Plants possess unique features in many aspects of development. One of these features is seen in cell wall placement during cytokinesis, which is determined by the position of the preprophase band (PPB) and the subsequent expansion of the phragmoplast that deposits the new cell wall. During phragmoplast expansion, the phragmoplast tracks to the cortical division site, which was delineated by the PPB. Thus the position of the PPB determines the orientation of the division plane. In Arabidopsis … more
Date: December 2013
Creator: Oremade, Oladapo O.
open access

Desire Lines: Dérive in Heterotopias

Description: This study provides an examination and application of heterotopic dérive, a concept that combines spatial theories originated by Foucault and psychogeographical methods advocated by the Situationists, as enacted within theatrical performance spaces. The first chapter reviews theories related to space, place, and heterotopias, as well as the psychogeographical methods of the Situationists, particularly the dérive. The literature review is augmented with accounts of my experiences of serendipit… more
Date: August 2018
Creator: Snider, Jesse Rhea
open access

A Detailed Investigation, Comparison, and Analysis of the Practice Habits of Undergraduate Vocal and Piano Performance Majors

Description: For musicians of all kinds, practice is an essential component in establishing and refining their skills. How a musician learns the art of practicing, and at what point in their musical and cognitive development can vary drastically. The purpose of this research is to understand how two groups of musicians, undergraduate vocal performance majors and undergraduate piano performance majors, developed (or consequently failed to develop) their respective knowledge pertaining to effective practice p… more
Date: December 2018
Creator: Radziun, Barrett
open access

Detecting Component Failures and Critical Components in Safety Critical Embedded Systems using Fault Tree Analysis

Description: Component failures can result in catastrophic behaviors in safety critical embedded systems, sometimes resulting in loss of life. Component failures can be treated as off nominal behaviors (ONBs) with respect to the components and sub systems involved in an embedded system. A lot of research is being carried out to tackle the problem of ONBs. These approaches are mainly focused on the states (i.e., desired and undesired states of a system at a given point of time to detect ONBs). In this paper,… more
Date: May 2018
Creator: Bhandaram, Abhinav
open access

Detection and Classification of Heart Sounds Using a Heart-Mobile Interface

Description: An early detection of heart disease can save lives, caution individuals and also help to determine the type of treatment to be given to the patients. The first test of diagnosing a heart disease is through auscultation - listening to the heart sounds. The interpretation of heart sounds is subjective and requires a professional skill to identify the abnormalities in these sounds. A medical practitioner uses a stethoscope to perform an initial screening by listening for irregular sounds from the … more
Date: December 2016
Creator: Thiyagaraja, Shanti
open access

Detection of Generalizable Clone Security Coding Bugs Using Graphs and Learning Algorithms

Description: This research methodology isolates coding properties and identifies the probability of security vulnerabilities using machine learning and historical data. Several approaches characterize the effectiveness of detecting security-related bugs that manifest as vulnerabilities, but none utilize vulnerability patch information. The main contribution of this research is a framework to analyze LLVM Intermediate Representation Code and merging core source code representations using source code properti… more
Date: December 2018
Creator: Mayo, Quentin R
open access

Detection of Harmful Chemicals in the Air using Portable Membrane Inlet Mass Spectrometry

Description: Portable mass spectrometry has become an important analytical tool for chemical detection and identification outside of a lab setting. Many variations and applications have been developed to benefit various fields of science. Membrane inlet mass spectrometry is used to allow certain analytes to pass into the mass spectrometer without breaking vacuum or letting in large particulate matter. These two important analytical tools have been applied to the detection of harmful chemicals in the air. Ea… more
Date: August 2018
Creator: Kretsch, Amanda Renee
open access

Detection of Mercury Among Avian Trophic Levels at Caddo Lake and Lake Lewisville, TX

Description: Mercury (Hg) is a globally distributed toxicant that has been shown to have negative effects on birds. in the United States, avian taxa have been shown to possess high Hg concentrations in the northeast, Great Lakes and Everglades ecosystems; however, few studies have measured avian Hg concentrations in other geographic regions. Previous studies have documented high Hg concentrations in multiple organisms in east Texas, but birds were not included in these studies. the main objective of the pre… more
Date: May 2012
Creator: Schulwitz, Sarah E.
open access

Detection of Temporal Events and Abnormal Images for Quality Analysis in Endoscopy Videos

Description: Recent reports suggest that measuring the objective quality is very essential towards the success of colonoscopy. Several quality indicators (i.e. metrics) proposed in recent studies are implemented in software systems that compute real-time quality scores for routine screening colonoscopy. Most quality metrics are derived based on various temporal events occurred during the colonoscopy procedure. The location of the phase boundary between the insertion and the withdrawal phases and the amount … more
Date: August 2013
Creator: Nawarathna, Ruwan D.
open access

Detection of Ulcerative Colitis Severity and Enhancement of Informative Frame Filtering Using Texture Analysis in Colonoscopy Videos

Description: There are several types of disorders that affect our colon’s ability to function properly such as colorectal cancer, ulcerative colitis, diverticulitis, irritable bowel syndrome and colonic polyps. Automatic detection of these diseases would inform the endoscopist of possible sub-optimal inspection during the colonoscopy procedure as well as save time during post-procedure evaluation. But existing systems only detects few of those disorders like colonic polyps. In this dissertation, we address … more
Date: December 2015
Creator: Dahal, Ashok
open access

Determinacy-related Consequences on Limit Superiors

Description: Laczkovich proved from ZF that, given a countable sequence of Borel sets on a perfect Polish space, if the limit superior along every subsequence was uncountable, then there was a particular subsequence whose intersection actually contained a perfect subset. Komjath later expanded the result to hold for analytic sets. In this paper, by adding AD and sometimes V=L(R) to our assumptions, we will extend the result further. This generalization will include the increasing of the length of the seq… more
Date: May 2013
Creator: Walker, Daniel
open access

The Determinants and Consequences of Empathic Parenting: Testing an Expansion of Belsky's Model of Parenting Using SEM

Description: An understanding of factors that enhance empathic parenting behaviors is of considerable importance to the study of child development and to the development of parenting interventions to promote child adjustment. Moreover, gaining a better understanding of the factors that predict empathic parenting with older children is of interest since most research examining parental empathy focuses on infants. These were the goals of the current study. Guided by Belsky's 1984 process model of the determ… more
Date: May 2010
Creator: Morse, Margaret K.
open access

Determinants and Impacts of Pinterest Consumer Experiences

Description: Pinterest is one of the fastest growing social networking sites and is attracting the interest of retailers as an effective way to interact with consumers. The purpose of this study was to examine: 1) determinants and impacts of Pinterest consumer experiences. Specifically, this study examined the impacts of retailer reputation, trust, perceived ease of use, and perceived usefulness on Pinterest consumer experiences on retailer SNS. 2) To identify the impacts of Pinterest consumer experiences o… more
Date: December 2014
Creator: Vasquez, Lauren
open access

Determinants of Citizens’ 311 Use Behaviors: 311 Citizen-initiated Contact, Contact Channel Choice, and Frequent Use

Description: Facing increasingly complex policy issues and diminishing citizen satisfaction with government and service performance, managing the quality of citizen relationship management has become a main challenge for public managers. Solutions to complex policy problems of service performance and low level of citizen participation often must be developed by encouraging citizens to make their voices heard through the various participation mechanisms. Reflecting on this need, the municipal governments in … more
Date: May 2015
Creator: Wu, Wei-Ning
open access

Determinants of Corporate Governance Choices: Evidence from Listed Foreign Firms on U.S. Stock Exchanges

Description: This study analyzes corporate governance practices of foreign (non-U.S.) issuers listed on the New York Stock Exchange (NYSE) and Nasdaq. Specifically, I examine the extent to which these foreign issuers voluntarily comply with U.S. stock exchange corporate governance requirements applicable to domestic issuers. My sample consists of 201 foreign companies primarily domiciled in Brazil, China, Israel, and the United Kingdom. I find that 151 (75 per cent) of the sample firms do not elect to compl… more
Date: May 2017
Creator: Attachot, Weerapat
Back to Top of Screen