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Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, Luke Metzler
Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, Luke Metzler
Electronic Theses and Dissertations
The nature of chemical interactions can be difficult to ascertain in the condensed phase; chemistry can be observed, but with the plethora of variables such as solvation, mixes of counter-ions, and complex equilibria, the true intrinsic chemical properties of a given chemical species may be obfuscated. By conducting research in the gas-phase, many of these variables can be reduced, if not eliminated entirely, which can allow for the careful observation of the true physical phenomena driving chemical reactivity.
The research presented herein focuses on the use of ion-trapping (specifically in a linear ion trap) as a method for unveiling the …
Elucidating The Pd Active Sites Of Bimetallic Gold-Palladium Catalysts Using Chemisorption And Titration Techniques, Andrew T. Boucher
Elucidating The Pd Active Sites Of Bimetallic Gold-Palladium Catalysts Using Chemisorption And Titration Techniques, Andrew T. Boucher
Electronic Theses and Dissertations
A bimetallic nanoparticle catalyst combines two different metals on an oxide support, which can increase the selectivity towards useful products that may be too tightly bound to a monometallic catalyst. To explore the surface properties of such a system, we made a group of four PdAu bimetallic catalysts with varying gold mass loadings to compare with a parent Pd catalyst. The parent catalyst was synthesized using ion exchange, and gold was added to this parent Pd catalyst using incipient wetness impregnation (IWI) to create four bimetallic catalysts. All catalysts were characterized using H2 and CO chemisorption in tandem with …
Bioinformatic Analysis Of The Interaction Of Evc And Evc2 Proteins, Md Atikul Islam Mamun
Bioinformatic Analysis Of The Interaction Of Evc And Evc2 Proteins, Md Atikul Islam Mamun
Electronic Theses and Dissertations
Protein to protein interactions are significant to various biological processes, functioning, and the regulation of cells and organisms. Proteins perform essential cellular tasks and often work together in complexes, enabling specific functions like enzymatic activity, signal transduction, DNA replication, and cell division. These interactions are important in signaling pathways, allowing proteins to interact sequentially, leading to specific cellular responses. Some proteins rely on chaperones to fold correctly, and protein to protein interactions enhance stability, preventing degradation.
Researchers at Stanford University School of Medicine discovered that EvC syndrome is related to a malfunction in the Hedgehog (Hh) signaling pathway. They found …
Measurements Of Atmospheric Radicals, Heather L. Runberg
Measurements Of Atmospheric Radicals, Heather L. Runberg
Electronic Theses and Dissertations
Atmospheric particulate matter (PM) is a global health concern. PM2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM2.5 result from events like volcanos and wildfires. Upon inhalation, PM2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.
PM2.5 is small enough to remain aloft and travel many hundreds …
The Impact Of Project-Based Learning On Students In High School Chemistry In Rural Maine, Brianna Degone
The Impact Of Project-Based Learning On Students In High School Chemistry In Rural Maine, Brianna Degone
Electronic Theses and Dissertations
Project-based learning (PBL) is an instructional strategy that is promoted throughout education for its use of active learning and ability to connect to real-world applications. Studies have been conducted on PBL ranging from early elementary grades through graduate courses, however little research considers the effectiveness of PBL at the secondary science level. This thesis considers the use of PBL and describes the implementation of a PBL unit in a rural Maine 11th grade chemistry classroom. The thesis aims to better understand the impact PBL has on students’ content learning and additional skills acquired through the PBL learning process. Along with …
A Computational Approach To Predicting And Understanding New Psychoactive Substances (Nps) For Developing A Database For State And Federal Crime Laboratories, Caroline Amelia Spencer
A Computational Approach To Predicting And Understanding New Psychoactive Substances (Nps) For Developing A Database For State And Federal Crime Laboratories, Caroline Amelia Spencer
Electronic Theses and Dissertations
The object of this dissertation was to use a computational approach to predict and understand new psychoactive substances (NPS) to develop a database for state and federal crime. The primary scope of the dissertation was to better understand the interactions that take place between new psychoactive substances and their corresponding receptors. Through analysis of the interactions between the amino acids within the receptors and the NPS an understanding into the pharmacology and toxicology of these drugs can be gained. NPS such as synthetic cannabinoids fentanyl and its analogs and kratom have become more problematic for both state and federal crime …
Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles
Groundwater Hydrogeolgy And Hydrochemistry Of Karst Springs In The Eastern Peninsula Of Fort Hood Military Installation, William Scribner Welles
Electronic Theses and Dissertations
The eastern peninsula of Fort Hood Military Installation is underlain by a complex karst spring network. These springs are a primary water source in a protected habitat for endangered songbirds, which has only recently begun to be fully investigated. These Fredericksburg Group springs express both epigenetic and hypogenetic karst signatures. The study area is part of a paleo reef trend, a hydraulically disconnected segment of the northern section of the Edwards Aquifer. This study utilized standard ion index values, repeated measures, and principal component analyses on the chemical profiles of six perennial springs to classify spring water sources and their …
Steric Effects Of Alkyl Ammonium Salts On The Combustion Of Exchanged Smectite Clays, Celeste A. Keith
Steric Effects Of Alkyl Ammonium Salts On The Combustion Of Exchanged Smectite Clays, Celeste A. Keith
Electronic Theses and Dissertations
Bomb calorimetry was explored as a new method for determining the cation exchange capacity (CEC) of clays. Smectite clays were modified with several alkyl ammonium salts varying in number of carbons and the spatial orientation of the carbons about the central nitrogen atom. The clays used, standards purchased from the Source Clay Repository, have CECs of 44, 80, 88, and 120 meq/100 g. Theoretically, the combustion energy of the organo-clays should be approximately the same for each salt. Any differences in energy would be due to the different structures of the salts and how they are oriented in the interlamellar …
A Comprehensive Analysis Of Aromatic-Proton Mediated Hydrogen Bonds, Mona S. Alshamrani
A Comprehensive Analysis Of Aromatic-Proton Mediated Hydrogen Bonds, Mona S. Alshamrani
Electronic Theses and Dissertations
Hydrogen bonds play critical role in folding, structure and recognition of biological macromolecules (e.g., proteins, RNA, DNA). In addition to classical hydrogen bonds (e.g., ─OH---O=, ─OH---O─, ─NH---O─ etc.), structural analysis of protein and nucleic acids, almost a decade ago, showed that hydrogen bonds (e.g., CH---O) with hydrogen atoms on aliphatic carbon atoms (hereafter, aliphatic-protons) also play very important role in the structure and function of biomolecules. Even though, protons of aromatic ring systems (hereafter, aromatic-protons) are more polar than the aliphatic-protons, systematic analysis of hydrogen bonds of aromatic-protons have not been carried out. Therefore, I carried out a systematic analysis …
Improvement And Development Of Analytical Forensic Methods: Arson Investigation And Drug Detection In Fingerprints And Hair, Sarah Anne Glenn
Improvement And Development Of Analytical Forensic Methods: Arson Investigation And Drug Detection In Fingerprints And Hair, Sarah Anne Glenn
Electronic Theses and Dissertations
Forensic science is the cornerstone of criminal investigations. Due to the overexposure of forensic science in the media, the true nature of forensic science is often overlooked. Forensic science is a rigorous exacting science that applies methods developed in the wider scientific community to the analysis of evidence collected from crime scenes. As far back as the 6th century people were using forensics to solve crimes. Since then the science behind forensic science has increased exponentially with new methods being researched and developed. This research aims to address two of the larger subsections of forensic science, arson and drug detection. …
Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk
Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk
Electronic Theses and Dissertations
This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.
In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted with halogens …
Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties, Praneeth Reddy Nimmala
Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties, Praneeth Reddy Nimmala
Electronic Theses and Dissertations
The term "Nano" in chemistry refers to particles/molecules in the size range 1 to 100 nm. Gold nanoparticles were used in ancient times in making decorative glass as they produce vibrant, size dependent, colors upon interaction with light. Gold is a preferred choice of metal for the synthesis of nanoparticles mainly due to its inertness to atmospheric conditions and most chemicals. Gold thiolate nanomolecules, which is the primary focus of this dissertation research, are chemical molecules with a fixed number of gold atoms and organo-thiolate ligands. They are of the form Aux(SR)y and possess molecule-like properties as a result of …
Multi-Configurational Investigation Of Thermolytic Pathways Of Highly Strained Ring Systems, Jeffrey Dwayne Veals
Multi-Configurational Investigation Of Thermolytic Pathways Of Highly Strained Ring Systems, Jeffrey Dwayne Veals
Electronic Theses and Dissertations
The isomerization pathways of model high energy structures are of interest because of their relation to high energy density fuels. Electron resonance has been found to greatly affect the relative activation barriers for several isomerization pathways, and the major goal of this research is to accurately describe its role in determining the relative barriers for strain energy release pathways. This research is centered around the potential energy surfaces (PES's) for ? bond breaking and ? bond rotation in these highly strained structures. Of particular interest was how would resonance and or electronegativity affect the allowed/disallonature of the activation barriers in …
Self-Assembly Of Squaraine Dyes, Maher A. Qaddoura
Self-Assembly Of Squaraine Dyes, Maher A. Qaddoura
Electronic Theses and Dissertations
Squaraine dyes have been a subject of extensive investigations lately due to their wide applications in important technological fields such as bioimaging probes, bioconjucation, second generation photosensitizers for photodynamic therapy, second harmonic generating organic dyes, two-photon absorbing materials with large cross section values, and, finally, photoconducting materials in photovoltaic cells. While a large number of patents and papers has been produced regarding their applications limited work has been done concerning their thermotropic behavior, including their liquid crystalline properties, or correlation of the crystalline structure to both the solid state aggregation and their photophysical properties. In the first chapter of this …
Development Of Novel Dart Tofms Analytical Techniques For The Identification Of Organic Contamination On Spaceflight-Related Substrates And Aqueous Media, Kathleen Loftin
Development Of Novel Dart Tofms Analytical Techniques For The Identification Of Organic Contamination On Spaceflight-Related Substrates And Aqueous Media, Kathleen Loftin
Electronic Theses and Dissertations
Organic contamination on spaceflight hardware is an ongoing concern for spaceflight safety. In addition, for the goal of analyzing for possible evidence of extra-terrestrial life, it is necessary to consider the presence of terrestrial contamination. This paper will introduce and evaluate a new method using a direct analysis real time (DART) ionization source paired with a high resolution time of flight mass spectrometer (TOFMS) for the determination of organic contamination involved in spaceflight hardware and ground support materials. This novel analytical technique has significant advantages over current methodologies. Materials analyzed in this study were historically considered as probable contaminants in …
Solution Processible Aromatic Polyimides Via Diels Alder Precursor, Saral Shah
Solution Processible Aromatic Polyimides Via Diels Alder Precursor, Saral Shah
Electronic Theses and Dissertations
Aromatic polyimides are interesting materials since they possess outstanding key properties such as thermoxidative stability, high mechanical strength, high modulus, excellent electrical properties, and superior chemical resistance. However, their low solubility makes them difficult to characterize, process and obtain high molecular weight polymer. In this report, we synthesized a series of precursor polymers that contains Diels-Alder (DA) adducts of anthracene. Different dienophiles were tried. These precursor polymers are soluble in common organic solvents such as chloroform and can be easily processed to thin films. Heating the film above 215 degree induce retro-DA reaction, which generated the fully aromatic polyimides in …
Theoretical Study On The Mechanism Of Removing Nitrogen Oxides Using Isocyanic Acid., Taraneh Nowroozi-Isfahani
Theoretical Study On The Mechanism Of Removing Nitrogen Oxides Using Isocyanic Acid., Taraneh Nowroozi-Isfahani
Electronic Theses and Dissertations
The mechanism of RAPRENOx reactions - RAPid REduction of Nitrogen Oxides using Isocyanic acid - proposed by Robert A. Perry1 in an attempt to help control the emission of nitrogen oxides pollutant into the atmosphere, has been re-investigated theoretically. The study of reaction mechanisms was carried out using Chemist software2. All mathematically possible elementary steps have been evaluated and the chemically reasonable ones have been considered to propose new sets of reaction mechanisms. Density Functional Theory (B3LYP/6-31 G**) calculations using Gaussian 983 were made in order to study the relative energies of all species and …
Grading The General Chemistry Laboratory: A Constructivist Approach., Barbara Stewart
Grading The General Chemistry Laboratory: A Constructivist Approach., Barbara Stewart
Electronic Theses and Dissertations
Constructivist theories of learning posit that instructors cannot transfer their knowledge to students; students must actively construct their own understanding. The Inter-Chem-Net project uses technology and instrumentation to provide an individualized experience within the large general laboratory course, effectively establishing a constructivist methodology. A grading rubric was developed to communicate course expectations and provide an easy and reliable method of evaluating student work in the general chemistry laboratory. The grading rubric separates the learning outcomes into a checklist of skills associated with each particular grade. This checklist provides detailed feedback for individualized choices of experiments, a key component of the …
Chemical Substitutes., Clarence Elmore Parks 1909-1987
Chemical Substitutes., Clarence Elmore Parks 1909-1987
Electronic Theses and Dissertations
No abstract provided.