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Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

Description: In this work we address two problems in computational chemistry relevant to biomolecular modeling. In the first project, we consider the conformer space of melatonin as a a representative example of “real-life” flexible biomolecules. Geometries for all 52 unique conformers are optimized using spin-component scaled MP2, and then relative energies are obtained at the CCSD (T) level near the complete basis set limit. These are then used to validate a variety of DFT methods with and without empiric… more
Date: August 2013
Creator: Fogueri, Uma
Item Type: Refine your search to only Thesis or Dissertation
open access

Acceptor-sensitizers for Nanostructured Oxide Semiconductor in Excitonic Solar Cells

Description: Organic dyes are examined in photoelectrochemical systems wherein they engage in thermal (rather than photoexcited) electron donation into metal oxide semiconductors. These studies are intended to elucidate fundamental parameters of electron transfer in photoelectrochemical cells. Development of novel methods for the structure/property tuning of electroactive dyes and the preparation of nanostructured semiconductors have also been discovered in the course of the presented work. Acceptor sensiti… more
Date: August 2014
Creator: Berhe, Seare Ahferom
Item Type: Refine your search to only Thesis or Dissertation
open access

Accuracy and Efficiency in Computational Chemistry: The Correlation Consistent Composite Approach

Description: One of the central concerns of computational chemistry is that of efficiency (i.e. the development of methodologies which will yield increased accuracy of prediction without requiring additional computational resources – RAM, disk space, computing time). Though the equations of quantum mechanics are known, the solutions to these equations often require a great deal of computing power. This dissertation primarily concerns the theme of improved computational efficiency (i.e. the achievement of g… more
Date: August 2011
Creator: Wilson, Brent R.
Item Type: Refine your search to only Thesis or Dissertation
open access

Accurate and Reliable Prediction of Energetic and Spectroscopic Properties Via Electronic Structure Methods

Description: Computational chemistry has led to the greater understanding of the molecular world, from the interaction of molecules, to the composition of molecular species and materials. Of the families of computational chemistry approaches available, the main families of electronic structure methods that are capable of accurate and/or reliable predictions of energetic, structural, and spectroscopic properties are ab initio methods and density functional theory (DFT). The focus of this dissertation is to … more
Date: August 2013
Creator: Laury, Marie L.
Item Type: Refine your search to only Thesis or Dissertation
open access

Accurate Energetics Across the Periodic Table Via Quantum Chemistry

Description: Greater understanding and accurate predictions of structural, thermochemical, and spectroscopic properties of chemical compounds is critical for the advancements of not only basic science, but also in applications needed for the growth and health of the U.S. economy. This dissertation includes new ab initio composite approaches to predict accurate energetics of lanthanide-containing compounds including relativistic effects, and optimization of parameters for semi-empirical methods for transitio… more
Date: December 2015
Creator: Peterson, Charles Campbell
Item Type: Refine your search to only Thesis or Dissertation
open access

Advancements in Instrumentation for Fourier Transform Microwave Spectroscopy

Description: The efforts of my research have led to the successful construction of several instruments that have helped expand the field of microwave spectroscopy. The classic Balle-Flygare spectrometer has been modified to include two different sets of antenna to operate in the frequency ranges 6-18 GHz and 18-26 GHz, allowing it to function for a large range without having to break vacuum. This modified FTMW instrument houses two low noise amplifiers in the vacuum chamber to allow for the LNAs to be as cl… more
Date: August 2011
Creator: Dewberry, Christopher Thomas
Item Type: Refine your search to only Thesis or Dissertation
open access

Affordances of Instrumentation in General Chemistry Laboratories

Description: The purpose of this study is to find out what students in the first chemistry course at the undergraduate level (general chemistry for science majors) know about the affordances of instrumentation used in the general chemistry laboratory and how their knowledge develops over time. Overall, students see the PASCO™ system as a useful and accurate measuring tool for general chemistry labs. They see the probeware as easy to use, portable, and able to interact with computers. Students find that the … more
Date: August 2010
Creator: Sherman, Kristin Mary Daniels
Item Type: Refine your search to only Thesis or Dissertation
open access

Allowing Students to Have VOICES (Voluntary Options in Chemical Education Schedules) in General Chemistry I

Description: The purpose of this investigation (a quasi-experimental design called a non-equivalent design group (NEDG)) was to determine if allowing students in a science majors general Chemistry I course the choice in establishing the due dates that their homework was due to the instructor would improve course averages. This study covered two semesters with a total of 288 students participating with n = 158 in the fall and n = 130 in the spring. The students self-selected the homework group, VOICES, tha… more
Date: December 2018
Creator: Ford, Robyn Lynn
Item Type: Refine your search to only Thesis or Dissertation
open access

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

Description: 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: Refine your search to only Thesis or Dissertation

Application-Focused Investigation of Monovalent Metal Complexes for Nanoparticle Synthesis

Description: Over the last 20 years, there has occurred an increase in the number, scope, and impact of nanomaterials projects. By leveraging the Surface Plasmon Resonance of metallic nanoparticles for labelling, sensing, and treatment, researchers have demonstrated the versatile utility of these nanomaterials in medicine. The literature provides evidence of use of simple, well-known chemistry for nanomaterials synthesis when the focus is new applications of nanomaterials. A case in point, is the synthes… more
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Date: August 2019
Creator: Kamras, Brian Leon
Item Type: Refine your search to only Thesis or Dissertation
open access

Application of the Correlation Consistent Composite Approach to Biological Systems and Noncovalent Interactions

Description: Advances in computing capabilities have facilitated the application of quantum mechanical methods to increasingly larger and more complex chemical systems, including weakly interacting and biologically relevant species. One such ab initio-based composite methodology, the correlation consistent composite approach (ccCA), has been shown to be reliable for the prediction of enthalpies of formation and reaction energies of main group species in the gas phase to within 1 kcal mol-1, on average, of w… more
Date: May 2015
Creator: Riojas, Amanda G.
Item Type: Refine your search to only Thesis or Dissertation
open access

Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths

Description: The continuously increasing demand for innovation in the miniaturization of microelectronics has driven the need for ever more precise fabrication strategies for device packaging, especially for printed circuit boards (PCBs). Subtractive copper etching is a fundamental step in the fabrication process, requiring very precise control of etch rate and etch factor. Changes in the etching chemical equilibrium have significant effects on etching behavior, and CuCl2 / HCl etching baths are typically m… more
Date: August 2017
Creator: Lambert, Alexander S.
Item Type: Refine your search to only Thesis or Dissertation
open access

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

Description: 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: Refine your search to only Thesis or Dissertation
open access

Applications of Single Reference Methods to Multi-Reference Problems

Description: Density functional theory is an efficient and useful method of solving single-reference computational chemistry problems, however it struggles with multi-reference systems. Modifications have been developed in order to improve the capabilities of density functional theory. In this work, density functional theory has been successfully applied to solve multi-reference systems with large amounts of non-dynamical correlation by use of modifications. It has also been successfully applied for geometr… more
Date: May 2015
Creator: Jeffrey, Chris C.
Item Type: Refine your search to only Thesis or Dissertation
open access

Biological Applications of a Strongly Luminescent Platinum (II) Complex in Reactive Oxygen Species Scavenging and Hypoxia Imaging in Caenorhabditis elegans

Description: Phosphorescent transition metal complexes make up an important group of compounds that continues to attract intense research owing to their intrinsic bioimaging applications that arise from bright emissions, relatively long excited state lifetimes, and large stokes shifts. Now for biomaging assay a model organism is required which must meet certain criteria for practical applications. The organism needs to be small, with a high turn-over of progeny (high fecundity), a short lifecycle, and low m… more
Date: December 2015
Creator: Kinyanjui, Sophia Nduta
Item Type: Refine your search to only Thesis or Dissertation
open access

Boron Nitride by Atomic Layer Deposition: A Template for Graphene Growth

Description: The growth of single and multilayer BN films on several substrates was investigated. A typical atomic layer deposition (ALD) process was demonstrated on Si(111) substrate with a growth rate of 1.1 Å/cycle which showed good agreement with the literature value and a near stoichiometric B/N ratio. Boron nitride films were also deposited by ALD on Cu poly crystal and Cu(111) single crystal substrates for the first time, and a growth rate of ~1ML/ALD cycle was obtained with a B/N ratio of ~2. The re… more
Date: August 2011
Creator: Zhou, Mi
Item Type: Refine your search to only Thesis or Dissertation
open access

Carbon Nanostructure Based Donor-acceptor Systems for Solar Energy Harvesting

Description: Carbon nanostructure based functional hybrid molecules hold promise in solarenergy harvesting. Research presented in this dissertation systematically investigates building of various donor-acceptor nanohybrid systems utilizing enriched single walled carbon nanotube and graphene with redox and photoactive molecules such as fullerene, porphyrin, and phthalocyanine. Design, synthesis, and characterization of the donor-acceptor hybrid systems have been carefully performed via supramolecular binding… more
Date: December 2013
Creator: Das, Sushanta Kumar
Item Type: Refine your search to only Thesis or Dissertation
open access

Characterization of Aprotic Solutes and Solvents Using Abraham Model Correlations

Description: Experimental data were obtained for the computation of mole fraction solubilities of three dichloronitrobenzenes in organic solvents at 25oC, and solubility ratios were obtained from this data. Abraham model equations were developed for solutes in tributyl phosphate that describe experimental values to within 0.15 log units, and correlations were made to describe solute partitioning in systems that contain either "wet" or "dry" tributyl phosphate. Abraham model correlations have also been devel… more
Date: December 2016
Creator: Brumfield, Michéla L.
Item Type: Refine your search to only Thesis or Dissertation
open access

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

Description: 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: Refine your search to only Thesis or Dissertation
open access

Characterization of Ionic Liquid Solvents Using a Temperature Independent, Ion-Specific Abraham Parameter Model

Description: Experimental data for the logarithm of the gas-to-ionic liquid partition coefficient (log K) have been compiled from the published literature for over 40 ionic liquids over a wide temperature range. Temperature independent correlations based on the Gibbs free energy equation utilizing known Abraham solvation model parameters have been derived for the prediction of log K for 12 ionic liquids to within a standard deviation of 0.114 log units over a temperature range of over 60 K. Temperature inde… more
Date: December 2014
Creator: Stephens, Timothy W.
Item Type: Refine your search to only Thesis or Dissertation
open access

Characterization of Novel Solvents and Absorbents for Chemical Separations

Description: Predictive methods have been employed to characterize chemical separation mediums including solvents and absorbents. These studies included creating Abraham solvation parameter models for room-temperature ionic liquids (RTILs) utilizing novel ion-specific and group contribution methodologies, polydimethyl siloxane (PDMS) utilizing standard methodology, and the micelles cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) utilizing a combined experimental setup methodology with … more
Date: May 2011
Creator: Grubbs, Laura Michelle Sprunger
Item Type: Refine your search to only Thesis or Dissertation
open access

Characterization of Post-Plasma Etch Residues and Plasma Induced Damage Evaluation on Patterned Porous Low-K Dielectrics Using MIR-IR Spectroscopy

Description: As the miniaturization of functional devices in integrated circuit (IC) continues to scale down to sub-nanometer size, the process complexity increases and makes materials characterization difficult. One of our research effort demonstrates the development and application of novel Multiple Internal Reflection Infrared Spectroscopy (MIR-IR) as a sensitive (sub-5 nm) metrology tool to provide precise chemical bonding information that can effectively guide through the development of more efficient … more
Date: May 2016
Creator: Rimal, Sirish
Item Type: Refine your search to only Thesis or Dissertation
open access

Chemical and Electronic Structure of Aromatic/Carborane Composite Films by PECVD for Neutron Detection

Description: Boron carbide-aromatic composites, formed by plasma-enhanced co-deposition of carboranes and aromatic precursors, present enhanced electron-hole separation as neutron detector. This is achieved by aromatic coordination to the carborane icosahedra and results in improved neutron detection efficiency. Photoemission (XPS) and FTIR suggest that chemical bonding between B atoms in icosahedra and aromatic contents with preservation of π system during plasma process. XPS, UPS, density functional theo… more
Date: December 2016
Creator: Dong, Bin
Item Type: Refine your search to only Thesis or Dissertation
open access

Chirped-Pulse Fourier Transform Microwave Spectroscopy of Fluoroiodoacetonitrile and Chloropentafluoroacetone

Description: This work focuses on finding the complete iodine and nitrogen nuclear electric quadrupole coupling tensors for fluoroiodoacetonitrile using chirped-pulse Fourier transform microwave spectroscopy. Fluoroiodoacetonitrile contains two hyperfine nuclei, iodine (I=5/2) and nitrogen (I=1) and the spectra were observed with great resolution. A total of 499 transitions were observed for this molecule. The a, b and c rotational constants were obtained. A study of chloropentafluoroacetone was also done u… more
Date: December 2010
Creator: Kadiwar, Gautam
Item Type: Refine your search to only Thesis or Dissertation
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