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Full-Text Articles in Physical Sciences and Mathematics

Supersonic Jet Spectroscopy Of Synthetic Foldamers, Multichromophores, And Their Water Containing Clusters, Evan Gardner Buchanan Oct 2014

Supersonic Jet Spectroscopy Of Synthetic Foldamers, Multichromophores, And Their Water Containing Clusters, Evan Gardner Buchanan

Open Access Dissertations

A central theme specific to this dissertation concerns the conformation-specific spectroscopy of flexible molecules in an effort to bridge the complexity gap. Generally, molecules in the complexity gap have several flexible coordinates yet conformational isomerization still occurs along a simple reaction coordinate on the potential energy surface. Molecules in this regime benefit greatly from experiments probing the potential energy surfaces and provide a means to develop and test new theories in an effort to explain more complex system. These measurements are possible through the utilization of a supersonic jet expansion to collisionally cool molecules into their vibrational zero-point levels, collapsing …


Determination Of Disulfide Bond Connecting Patterns Via Tandem Mass Spectrometry (Msn) And Biomolecular Ion/Radical Reactions, Kirt Lenroy Durand Oct 2014

Determination Of Disulfide Bond Connecting Patterns Via Tandem Mass Spectrometry (Msn) And Biomolecular Ion/Radical Reactions, Kirt Lenroy Durand

Open Access Dissertations

Disulfide bond formation is one of the most common post translational modifications to occur in proteins and naturally occurring peptides. Disulfide bond formation plays a critical role in stabilizing their three-dimensional structure; therefore, it is very important to pinpoint the correct disulfide bond connecting pattern in order to fully understand the biological functions of these proteins and peptides. To fully characterize an analyte containing disulfide bonds, the sequence must first be known followed by the disulfide bond connecting pattern. This presents an analytical challenge as there are very few methodologies that can produce those essential pieces of information. The gold …


Excited States Of Chromophores And Vibronic Interactions, Benjamin T. Nebgen Oct 2014

Excited States Of Chromophores And Vibronic Interactions, Benjamin T. Nebgen

Open Access Dissertations

The main focus of my Ph.D. work has been on building a vibronic coupling model for multichromophores and extending that model to more general systems. This Dissertation serves as both a summary of this work as well as a manual for the two vibronic coupling programs I have written. It is my hope that the instructions written here are complete enough for any who would like to replicate my work on vibronic coupling on other systems. ^ Additionally, I have also worked on a few purely computational projects not directly related to the vibronic coupling work. The status of these …


Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan Jul 2014

Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan

Open Access Theses

There are five major mechanisms of water-solid interactions. The primary focus of this thesis was on two of these: deliquescence and hydrate formation. Many crystalline food ingredients are deliquescent compounds (e.g., NaCl, sucrose, and ascorbic acid) and some are both deliquescent and hydrate formers (e.g., glucose, thiamine HCl, citric acid). Deliquescence is the first order phase transformation of a crystalline solid to a solution above a critical relative humidity (RH) known as the deliquescence point (RH0). A crystalline hydrate is a pseudo-polymorph in which water is incorporated into the crystal structure, altering the molecular formula and the physical properties.^ To …


Gas-Phase Ion/Ion Reactions Of Biomolecules: An Examination Of Carboxylate Reactivity And Arginine Based Non-Covalent Complexes, Nathan Zachary Barefoot Jul 2014

Gas-Phase Ion/Ion Reactions Of Biomolecules: An Examination Of Carboxylate Reactivity And Arginine Based Non-Covalent Complexes, Nathan Zachary Barefoot

Open Access Theses

The advent of Electrospray Ionization with the ability to generate multiply charges ions has contributed significantly to the study of gas-phase ion/ion reactions. With the tools available in mass spectrometry it has been shown that these reactions are effective at transforming one type of gaseous ion into another through a series of reactions. This work examines some of these reactions and their application to field of proteomics specifically focusing on the amino acids of arginine and lysine. NHS reagents have been shown to react to both of these molecules with in the gas-phase under different conditions but have relies on …


Fundamental Studies On Copper Zeolites For Catalytic No X Abatement, Anuj Arun Verma Jul 2014

Fundamental Studies On Copper Zeolites For Catalytic No X Abatement, Anuj Arun Verma

Open Access Dissertations

Stringent regulations in mobile NOx emissions have resulted in the development of Standard Selective Catalytic Reduction (SCR) as the dominant NOx abatement technology in lean burn diesel engines. Standard SCR is a reaction of nitric oxide (NO) with ammonia (NH3), in the presence of oxygen (O 2) to form nitrogen (N2) and water (H2O). Copper containing zeolites show commercially viable SCR performance. Cu-SSZ-13 (CHA framework), a member of this family, is a preferred catalyst for SCR applications because it shows exceptional hydrothermal stability in addition to commercially viable SCR performance. Our work focuses …


Investigation Of Isotope Effects Of Ozone As A Function Of Temperature, Daniel J. Mcmahon Apr 2014

Investigation Of Isotope Effects Of Ozone As A Function Of Temperature, Daniel J. Mcmahon

Open Access Theses

Ozone is an important oxidizer in the atmosphere and plays a crucial role as a cleanser, removing various compounds such NOx and SOx. It also is intriguing to those that study stable isotopes as it has a unique signature found in no other oxygen containing molecule. Ozone is observed to fractionate mass independently, which means it does not follow the typical δ 17 O /δ18 O = 0.52 ratio expected for molecules enriched with 17 O and 18 O. The magnitude of ozone's mass independent enrichment has been studied in laboratory experiments and atmospheric observations but its explanation is still …


Reactivity Studies Of Tridhydropyridine Radical Cautions By Using Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry And Advancement Of Mass Spectrometric Analysis Of Asphaltenes And Degradation Products, Mohammad Sabir Aqueel Apr 2014

Reactivity Studies Of Tridhydropyridine Radical Cautions By Using Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry And Advancement Of Mass Spectrometric Analysis Of Asphaltenes And Degradation Products, Mohammad Sabir Aqueel

Open Access Dissertations

Aromatic organic molecules which have unpaired electrons play an important role in a variety of applications in the fields of organic synthesis, organic magnets, and biological activity of organic compounds. Several studies have been published on σ- type carbon-centered mono- and biradicals. Reactive intermediates with three formally unpaired electrons are known as triradicals. They can be defined as species with three electrons distributed in three degenerate or nearly degenerate orbitals, based on Salem's definition of biradicals from the electronic structure point of view. Very little is known about the reactivity of carbon-centered σ,σ,σ- triradicals due to the complexity of studying …