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Soft Landing Ion Mobility Mass Spectrometry: History, Instrumentation and an Ambient Pressure Application

Preparative mass spectrometry is an important method for the synthesis of new materials. Recently, soft landing mass spectrometry has been used to land ions on surfaces to coat or otherwise alter them. Commercial soft landing instruments do not yet exist, and the physical phenomenon of soft landing has not yet been fully described. For future ion mobility soft landing research, the theory of ion mobility, ion optics and soft landing is discussed, and 2 soft landing instruments have been built a… more

Date: December 2010

Creator: Birdwell, David

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Comparison of Homework Systems (Four Web-Based) used in First-Semester General Chemistry

Web-based homework systems are becoming more common in general chemistry as instructors face ever-increasing enrollment. Yet providing meaningful feedback on assignments remains of the utmost importance. Chemistry instructors consider completion of homework integral to students' success in chemistry, yet only a few studies have compared the use of Web-based systems to the traditional paper-and-pencil homework within general chemistry. This study compares the traditional homework system to four … more

Date: May 2009

Creator: Belland, Joshua

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Synthesis and Screening of a Combinatorial Peptide Library for Ligands to Target Transferrin: Miniaturizing the Library

Combinatorial libraries are used in the search for ligands that bind to target proteins. Fmoc solid-phase peptide synthesis is routinely used to generate such libraries. Microwave-assisted peptide synthesis was employed here to decrease reaction times by 80-90%. Two One-Bead-One-Compound combinatorial libraries were synthesized on 130μm beads (one containing 750 members and the other 16, 807). The use of smaller solid supports would have many important practical advantages including; increased … more

Date: August 2010

Creator: Brown, Jennifer Marie

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Forensic Science Applications Utilizing Nanomanipulation-Coupled to Nanospray Ionization-Mass Spectrometry for the Analysis of Ultra-Trace Illicit Drugs

Presented in this thesis are two methods that are coupled to the instrumentation for the recovery and analysis of ultra-trace illicit drug residues. The electrostatic dust lifting process is coupled with nanomanipulation-nanospray ionization to retrieve drug particles off of hard surfaces for analysis. For the second method, drug residues from fingerprint impressions are extracted followed by analysis. The methodology of these hyphenated techniques toward forensic science applications is applie… more

Date: December 2010

Creator: Wallace, Nicole

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Data Mining Using Direct Injection Triple Quadrupole Mass Spectrometry, Infrared Spectroscopy, Inductively Coupled Plasma Optical Emission Spectroscopy, and Polymerase Chain Reaction for the Rapid Identification of Nutraceuticals and Contaminants

There has been a rapid surge toward "organic" products devoid of GMOs, MSGs, and other common compounds found in processed foods that continue to indicate an association with an increased risk for disease. These consumers seek nutrients and vitamins that are lacking in their diet and lifestyle in the form of nutraceuticals for disease prevention and treatment as well as overall lifestyle enhancement. However, these products generally lack clinical evidence as well as legal definition. Due to th… more

Date: December 2022

Creator: Yazici, Micayla Rose Morgan

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

FTIR-ATR Characterization of Hydrogel, Polymer Films, Protein Immobilization and Benzotriazole Adsorption on Copper Surface

Plasma polymerization techniques were used to synthesize and deposit hydrogel on silicon (Si) substrate. Hydrogel is a network of polymer chains that are water-insoluble and has a high degree of flexibility. The various fields of applications of hydrogel include drug release, biosensors and tissue engineering etc. Hydrogel synthesized from different monomers possess a common property of moisture absorption. In this work two monomers were used namely 1-amino-2-propanol (1A2P) and 2(ethylamin… more

Date: December 2007

Creator: Pillai, Karthikeyan

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Study of Silver Deposition on Silicon (100) by IR Spectroscopy and Patina Formation Study of Oxygen Reduction Reaction on Ruthenium or Platinum

To investigate conditions of silver electroless deposition on silicon (100), optical microscope, atomic force microscope (AFM) and attenuated total reflection infrared spectroscopy (ATR-FTIR) spectroscopy were used. Twenty second dipping in 0.8mM AgNO3/4.9% solution coats a silicon (100) wafer with a thin film of silver nanoparticles very well. According to AFM results, the diameter of silver particles is from 50 to 100nm. After deposition, arithmetic average of absolute values roughness (Ra) i… more

Date: August 2009

Creator: Yang, Fan

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Electrodeposition of Copper on Ruthenium Oxides and Bimetallic Corrosion of Copper/Ruthenium in Polyphenolic Antioxidants

Copper (Cu) electrodeposition on ruthenium (Ru) oxides was studied due to important implications in semiconductor industry. Ruthenium, proposed as the copper diffusion barrier/liner material, has higher oxygen affinity to form different oxides. Three different oxides (the native oxide, reversible oxide, and irreversible oxide) were studied. Native oxide can be formed on exposing Ru in atmosphere. The reversible and irreversible oxides can be formed by applying electrochemical potential. Investi… more

Date: August 2007

Creator: Venkataraman, Shyam S.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Applications of Nanomanipulation Coupled to Nanospray Mass Spectrometry in Trace Fiber Analysis and Cellular Lipid Analysis.

The novel instrumentation of nanomanipulation coupled to nanospray mass spectrometry and its applications are presented. The nanomanipulator has the resolution of 10nm step sizes allowing for specific fine movement used to probe and characterize objects of interest. Nanospray mass spectrometry only needs a minimum sample volume of 300nl and a minimum sample size of 300attograms to analyze an analyte making it the ideal instrument to couple to nanomanipulation. The nanomanipulator is mounted to … more

Date: December 2008

Creator: Ledbetter, Nicole

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Semiconducting Aromatic Boron Carbide Films for Neutron Detection and Photovoltaic Applications

Semiconducting aromatic-boron carbide composite/alloyed films formed by plasma enhanced chemical vapor deposition from carborane and aromatic precursors have been demonstrated to be excellent detectors for thermal neutrons because of the large 10B cross section. The electronic properties of these films derived from XPS show that the properties of boron carbide can be tuned by co-deposition of aromatic compounds and carborane. Aromatic doping results in narrower indirect band gaps (1.1 - 1.7 eV … more

Date: December 2019

Creator: Oyelade, Adeola O

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Characterization of Ionic Liquid As a Charge Carrier for the Detection of Neutral Organometallic Complexes Using Electrospray Ionization Mass Spectrometry

A novel application of ionic liquid as a charge carrier for the analysis and detection of neutral organometallic complexes using a mass spectrometer has been presented. The mass spectrometer detects only charged compounds which raise a difficulty in analyzing a neutral molecule that lacks a basic site to associate with charge. Therefore, an effective way of providing charge has always been an area of keen interest in the field of mass spectrometry. Ionic liquids have a very fascinating property… more

Date: August 2012

Creator: Joshi, Ubisha

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Novel LC-MS Method for the Analysis of Beta-Hydroxybutyric Acid (BHB) in Health Formulations

The rise of nutraceutical health formulations has increased the need for more stringent analytical testing methods. Complex matrices present a new problem when determining concentration of compounds of interest. The presented method uses LC-MS analysis with a novel sample preparation method in the determination of Beta-hydroxybutyric acid in health formulations. The use of an aqueous analytical column allows for separations of polar compounds after non-polar compounds are removed through C18 pa… more

Date: May 2022

Creator: Smith, Garret Mackenzie

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Analysis of N-Acylethanolamines in the Oilseed Crop Camelina sativa

To better understand the nature and function of N-acylethanolamines (NAEs) in Camelina sativa, we used mass spectrometry analysis to identify and quantify NAE types in developing seeds, desiccated seeds and seedlings. Developing seeds showed a differential increase in individual NAE species and an overall increase in NAE content with seed development and maturation. The NAE composition in mature, desiccated seeds mostly reflected the total fatty acid composition in the seed tissues, except fo… more

Date: August 2020

Creator: Corley, Chase D

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Utilizing Rapid Mass Spectrometry Techniques to Profile Illicit Drugs from Start to Finish

The increasingly complex world of illicit chemistry has created a need for rapid, selective means of determining the threat posed by new drugs as they are encountered by law enforcement personnel. To streamline this process, the entirety of the problem, from the production of illicit drugs all the way to the final analysis have been investigated. A series of N-alkylated phenethylamine analogues were synthesized in a shotgun method and subjected to direct-infusion analysis. A range of products w… more

Date: August 2018

Creator: McBride, Ethan

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

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

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

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Analysis of Trace Amounts of Adulterants Found in Powders/Supplements Utilizing Direct Inject, Nanomanipulation, and Mass Spectrometry

The regulations of many food products in the United States have been made and followed very well but unfortunately some products are not put under such rigorous standards as others. This leads to products being sold, that are thought to be healthy, but in reality contain unknown ingredients that may be hazardous to the consumers. With the use of several instrumentations and techniques the detection, characterization and identification of these unknown contaminates can be determined. Both the AZ… more

Date: August 2016

Creator: Nnaji, Chinyere

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Atomic Layer Deposition of H-BN(0001) on Transition Metal Substrates, and In Situ XPS Study of Carbonate Removal from Lithium Garnet Surfaces

The direct epitaxial growth of multilayer BN by atomic layer deposition is of critical significance forfo two-dimensional device applications. X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) demonstrate layer-by-layer BN epitaxy on two different substrates. One substrate was a monolayer of RuO2(110) formed on a Ru(0001) substrate, the other was an atomically clean Ni(111) single crystal. Growth was accomplished atomic layer deposition (ALD) cycles of BCl3/NH… more

Date: May 2020

Creator: Jones, Jessica C.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Study of Novel Ion/surface Interactions Using Soft-landing Ion Mobility

Preparative mass spectrometry is a gas-phase ion deposition technique aimed at deposition of monodisperse ion beams on a surface. This is accomplished through the implementation of a soft-landing ion mobility system which allows for high ion flux of conformationally selected ion packets. The soft-landing ion mobility system has been applied to a number of unique chemical problems including the deposition of insulators on graphene, the preparation of reusable surface enhanced Raman spectroscop… more

Date: December 2012

Creator: Hoffmann, William Darryle

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Impact of Texas High School Science Teacher Credentials on Student Performance in High School Science

A study was conducted to determine the relationship between the credentials held by science teachers who taught at a school that administered the Science Texas Assessment on Knowledge and Skills (Science TAKS), the state standardized exam in science, at grade 11 and student performance on a state standardized exam in science administered in grade 11. Years of teaching experience, teacher certification type(s), highest degree level held, teacher and school demographic information, and the percen… more

Date: August 2012

Creator: George, Anna Ray Bayless

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Miniature Mass Spectrometry: Theory, Development and Applications

As mass analyzer technology has continued to improve over the last fifty years, the prospect of field-portable mass spectrometers has garnered interest from many research groups and organizations. Designing a field portable instrument entails more than the scaling down of current commercial systems. Additional considerations such as power consumption, vacuum requirements and ruggedization also play key roles. In this research, two avenues were pursued in the initial development of a portable… more

Date: December 2013

Creator: Fox, James D.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Design and Development of a Paper Spray Air Sampling Device for Use in Clinical, Defense, and Environmental Applications

Environmental monitoring is becoming increasingly important, primarily in urban areas due to the concentrated levels of human activities. The air sampling device presented is a novel method to sample air which harnesses the power of paper spray ionization paired with the intrinsic advantages of mass spectrometry such as high sensitivity, high selectivity, high throughput, and the ability to monitor multiple compounds at once.

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Date: December 2023

Creator: Murillo, Wilbert Alberto

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Studies on the Porphyrin and Phthalocyanine Modified on Sno2 Photoelectrochemical Cells

The world is facing a tough challenge regarding fulfilling human energy needs. Scientists are motivated to find alternative ways to the fossil fuel at a lower cost with little or no environmental pollution. Among the available renewable resources, the solar energy is an alternative energy to fossil fuel. Scientists are engaged in mimicking the photosynthesis to create the new energy devices such as dye sensitized solar cells. The fundamental theory and properties of the dye sensitized solar cel… more

Date: December 2013

Creator: Lin, Chunyu

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Laser Ablation Inductively Coupled Plasma Mass Spectrometry and Raman Spectroscopy Imaging of Biological Tissues

Laser Ablation Inductively coupled plasma mass spectrometry (LA-ICP-MS) and Raman spectroscopy are both powerful imaging techniques. Their applications are numerous and extremely potential in the field of biology. In order to improve upon LA-ICP-MS an in-house built cold cell was developed and its effectiveness studied by imaging Brassica napus seeds. To further apply LA-ICP-MS and Raman imaging to the field of entomology a prong gilled mayfly (Ephemeroptera: Leptophlebiidae) from the Róbalo Ri… more

Date: May 2016

Creator: Gorishek, Emma Lee

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Applications of Metallic Clusters and Nanoparticles via Soft Landing Ion Mobility, from Reduced to Ambient Pressures

Nanoparticles, simple yet groundbreaking objects have led to the discovery of invaluable information due to their physiological, chemical, and physical properties, have become a hot topic in various fields of study including but not limited to chemistry, biology, and physics. In the work presented here, demonstrations of various applications of chemical free nanoparticles are explored, from the determination of a non-invasive method for the study of the exposome via using soft-landing ion mobil… more

Date: August 2018

Creator: Aguilar Ayala, Roberto

Item Type: Thesis or Dissertation

Partner: UNT Libraries