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Full-Text Articles in Physical Sciences and Mathematics
Complex Mixtures: Identifying And Characterizing Secondary Organic Aerosols, Emma Quinn Walhout
Complex Mixtures: Identifying And Characterizing Secondary Organic Aerosols, Emma Quinn Walhout
Dissertations, Theses, and Masters Projects
Complex organic mixtures in the environment can contain hundreds to thousands of different organic molecules, and their composition and reactivity can have important environmental implications. In addition to gases, the atmosphere is made of a variety of small liquids and solids called aerosols. These aerosols have large impacts on human health, climate, and atmospheric chemical reactions. Here, secondary organic aerosol (SOA) from the ozonolysis of α-pinene is characterized. The atmospheric lifetime of SOA is very uncertain, but recent laboratory and modeling studies have demonstrated that photolysis is potentially an important process for organic mass loss from aerosol particles.1-5 Photolysis modifies …
Computational Investigations Of The Structure And Spectroscopy Of Small Biomolecules In The Gas Phase, Zachary Michael Smith
Computational Investigations Of The Structure And Spectroscopy Of Small Biomolecules In The Gas Phase, Zachary Michael Smith
Dissertations, Theses, and Masters Projects
Small biomolecule systems were interrogated using infrared multiple photon dissociation (IRMPD) action spectroscopy and corresponding quantum chemical calculations with a particular focus on peptide fragmentation and protonation site preference. b2+ and b3+ fragment ions with a terminal lysine homolog residue were investigated using IRMPD in the fingerprint region (1000 cm-1 – 2000 cm-1) and a variety of computational methods. We present the first spectroscopic confirmation of b-ion formation with a lactam structure. Infrared spectra for b2+ fragment system indicate the presence of a mixture of structures, though final determination will require further investigation. The b3+ fragment ion infrared spectra show …
Monitoring Infection Of E. Coli By Bacteriophage T7 Through Mass Spectrometry-Based Proteomics, Amy Swayne Schienschang
Monitoring Infection Of E. Coli By Bacteriophage T7 Through Mass Spectrometry-Based Proteomics, Amy Swayne Schienschang
Dissertations, Theses, and Masters Projects
Mass spectrometry-based proteomics has become an important and versatile tool in analytical chemistry, making sense of complex biological samples and shedding light on the intricate proteomes of living organisms. Bottom-up proteomics studies are used to elucidate the changes in gene expression of bacteriophage T7 over the course of infection of Escherichia coli. E. coli cultures were infected with T7, sampled over time, and proteins were isolated and enzymatically digested. Nanoflow liquid chromatography combined with tandem mass spectrometry was used to detect proteolytic peptides and identify host and phage proteins. Generally, phage proteins were detected on a time scale fitting the …
Studies Of Molecular Dynamics Of Fmoc Amino Acids Using Solid State Deuteron Nuclear Magnetic Resonance Spectroscopy, Wei Xu
Dissertations, Theses, and Masters Projects
The purpose of devising and validating models for intramolecular motions for FMOC amino acids is to quantify side chain motion in proteins which plays an important role in understanding biological structure function relations of proteins. In this thesis, spin lattice relaxation times (Ti) of FMOC amino acids were m easured under both static and magic angle spinning (MAS) condition at variable tem peratures. Lower activation energies of the relaxation times than the normal amino acids observed indicate a less sterically crowded environment for the rotation methyl group. A three-site jump model for the methyl group w as developed to fit …
Surface-Enhanced Raman And Single-Molecule Spectroscopy Studies Of Fugitive Artists' Pigments, Kristen A. Frano
Surface-Enhanced Raman And Single-Molecule Spectroscopy Studies Of Fugitive Artists' Pigments, Kristen A. Frano
Dissertations, Theses, and Masters Projects
No abstract provided.
Electroless Gold Deposition With Self-Assembled Monolayers For Gas Chromatography Stationary Phases, Jessica Lynn Belton
Electroless Gold Deposition With Self-Assembled Monolayers For Gas Chromatography Stationary Phases, Jessica Lynn Belton
Dissertations, Theses, and Masters Projects
No abstract provided.
Surface Modifications For Gas Chromatography Micro Columns, Daniel Andre Hirtenstein
Surface Modifications For Gas Chromatography Micro Columns, Daniel Andre Hirtenstein
Dissertations, Theses, and Masters Projects
No abstract provided.
Thermochemistry Of Amino Acids And Constrained Diamines, Erica Jane Tullo
Thermochemistry Of Amino Acids And Constrained Diamines, Erica Jane Tullo
Dissertations, Theses, and Masters Projects
The gas-phase proton affinities of several highly basic amino acids and diamines were determined using the extended kinetic method in an ESI-quadrupole ion trap instrument. The non-protein amino acid L-canavanine is structurally related to L-arginine with an oxygen substituted for the terminal methylene group of L-arginine and is highly toxic to humans. The proton affinity of L-arginine, a protein amino acid, was determined to be 1036 kJ mol -1, whereas the proton affinity of L-canavanine was determined to be 1005 kJ mol-1. Thus, substitution of an oxyguanidino group for the guanidine group in L-arginine results in a large decrease in …
The Development And Application Of An Antibody-Based Biosensor For The Detection Of The Petroleum-Derived Compounds, Candace Rae Spier
The Development And Application Of An Antibody-Based Biosensor For The Detection Of The Petroleum-Derived Compounds, Candace Rae Spier
Dissertations, Theses, and Masters Projects
Petroleum is one of the most important natural resources, but can also be problematic to environmental and human health. Petroleum is comprised of thousands of compounds, including polycyclic aromatic hydrocarbons (PAHs) and heterocycles, some of which are toxic and/or carcinogenic. Traditional analytical methods for environmental monitoring of low-level PAHs are time-consuming labor-intensive, and often laboratory-bound. Efforts to achieve timely, sensitive, and accurate analysis of PAHs in the field have become a priority for environmental research and monitoring. Antibody-based biosensors are presently being developed for environmental analysis. Anti-PAH antibody molecules can be coupled with electronic transducers to provide new biosensor technology …
Bioavailability Of Biosolids- And Consumer Product-Associated Polybrominated Diphenyl Ether (Pbde) Flame Retardants To Terrestrial Invertebrates, Michael O. Gaylor
Bioavailability Of Biosolids- And Consumer Product-Associated Polybrominated Diphenyl Ether (Pbde) Flame Retardants To Terrestrial Invertebrates, Michael O. Gaylor
Dissertations, Theses, and Masters Projects
The primary objectives of this research were therefore to evaluate polybrominated diphenyl ether (PBDE) bioavailability to ecologically distinct soil invertebrates exposed to Penta-BDE-treated consumer polyurethane foam (PUF) products and biosolid products with incurred PBDEs. In laboratory bioassays, earthworms (Eisenia fetida) bioaccumulated SigmaPBDEs (47+99+100+183) up to 11,000 mug/kg lipid after 28 days from a mixture of artificial soil and anaerobically-digested sludge biosolid (ADB). Earthworms also bioaccumulated SigmaPBDEs (47+99+100+153+154+183) up to 13,500 and 838,000 mug/kg lipid after 28 d from a mixture of artificial soil and composted sludge biosolid (CB) and Penta-BDE-spiked artificial soil (SAS), respectively. No previous lab studies on bioaccumulation …
Identification And Quantification Of Polycyclic Musks And Methyl-Triclosan In Unknown Freshwater Fish Tissue Samples, Elizabeth Mara Jacobs
Identification And Quantification Of Polycyclic Musks And Methyl-Triclosan In Unknown Freshwater Fish Tissue Samples, Elizabeth Mara Jacobs
Dissertations, Theses, and Masters Projects
No abstract provided.
Environmental Analysis Of Selected Estrogens And Androgens: Applying Ultra-Performance Liquid Chromatography And Combating Matrix Interference, Stacie L. Rice
Environmental Analysis Of Selected Estrogens And Androgens: Applying Ultra-Performance Liquid Chromatography And Combating Matrix Interference, Stacie L. Rice
Dissertations, Theses, and Masters Projects
Investigations of environmental hormone contamination commonly utilize solidphase extraction (SPE) followed by high-performance liquid chromatography / (electrospray ionization) tandem mass spectrometry (HPLC/(ESI)MS2) in the detection of estrogens. Matrix interference is widely reported. In this study, androgens were targeted alongside estrogens as environmentally co-introduced endocrine disrupting chemicals. Analytical methods were developed in parallel for detection of several hormones from each class, with comparison of protocols and instrumental parameters. Ultraperformance LC (UPLC®), an emerging technology advertised for reduced retention times, was used in place of HPLC for hormone separation. Applicability to diverse aqueous samples was tested. Matrix interference was combated with two …
Novel Derivatizing Agents For The Determination Of Methylmercury By Gas Chromatography Using Electron Capture Detection, Crystal Marie Irwin
Novel Derivatizing Agents For The Determination Of Methylmercury By Gas Chromatography Using Electron Capture Detection, Crystal Marie Irwin
Dissertations, Theses, and Masters Projects
No abstract provided.
Automated Peak Identification For Time -Of -Flight Mass Spectroscopy, Haijian Chen
Automated Peak Identification For Time -Of -Flight Mass Spectroscopy, Haijian Chen
Dissertations, Theses, and Masters Projects
The high throughput capabilities of protein mass fingerprints measurements have made mass spectrometry one of the standard tools for proteomic research, such as biomarker discovery. However, the analysis of large raw data sets produced by the time-of-flight (TOF) spectrometers creates a bottleneck in the discovery process. One specific challenge is the preprocessing and identification of mass peaks corresponding to important biological molecules. The accuracy of mass assignment is another limitation when comparing mass fingerprints with databases.;We have developed an automated peak picking algorithm based on a maximum likelihood approach that effectively and efficiently detects peaks in a time-of-flight secondary ion …
Heavy Metal Complexes Of Mixed S,N Donor Ligands: X-Ray Crystallography And Solution-State 1h Nmr, Wei Lai
Heavy Metal Complexes Of Mixed S,N Donor Ligands: X-Ray Crystallography And Solution-State 1h Nmr, Wei Lai
Dissertations, Theses, and Masters Projects
No abstract provided.
Characterization Of Ionic, Dipolar And Molecular Mobility In Polymer Systems, Zhenrong Guo
Characterization Of Ionic, Dipolar And Molecular Mobility In Polymer Systems, Zhenrong Guo
Dissertations, Theses, and Masters Projects
Changes in the ionic and dipolar molecular mobility in a polymer system are the basis for the changes in the dielectric mechanical properties of polymer materials. Frequency Dependent Dielectric Measurements (FDEMS) and Ion Time-of-Flight (ITOF) are two important techniques to investigate ionic and dipolar molecular mobility in polymer systems. The results can be related to the macro- and molecular dielectric, electrical and dynamic properties of polymeric materials. The combination of these two methods provides a full view of electric, dielectric and dynamic behavior for the systems as they undergo chemical and/or physical changes during polymerization crystallization, vitrification, and/or phase separation.;The …
Development Of A Technique To Isolate Measurement Of Ionic Mobility, Jie Guo
Development Of A Technique To Isolate Measurement Of Ionic Mobility, Jie Guo
Dissertations, Theses, and Masters Projects
No abstract provided.
Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin
Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin
Dissertations, Theses, and Masters Projects
The interactive effects of humic acids (HAs) and salinity on the bioavailability and toxicity of the pesticides chlorpyrifos and 4,4'-dichlorodiphenyltrichloroethane (DDT) were investigated. The effects of various HAs on the toxicity of chlorpyrifos were initially assessed with the chronic MicrotoxRTM test. Environmentally relevant concentrations of Aldrich, Peat, Leonardite and Suwannee River HAs had no significant effect on the toxicity of either chlorpyrifos or copper (Cu), the test's positive control. as reductions in contaminant toxicity had previously been reported for some contaminants by HAs, it appeared that salinity might be a mitigating factor. Thus salinity effects were further investigated with Aldrich …
Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Imidazole Based Ligands By X-Ray Crystallography And Nmr Spectroscopy, Geoffrey Murphy
Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Imidazole Based Ligands By X-Ray Crystallography And Nmr Spectroscopy, Geoffrey Murphy
Dissertations, Theses, and Masters Projects
No abstract provided.
Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers
Determination Of Trace Levels Of Lead In Whole Blood By Graphite Furnace Atomic Absorption Spectroscopy, Leslie A. Sombers
Dissertations, Theses, and Masters Projects
No abstract provided.
Development Of A Quantitative Competetive Polymerase Chain Reaction Assay For The Detection And Quantitation Of Perkinsus Marinus In Oyster Tissues And Environmental Water Samples, Heather A. Yarnall
Development Of A Quantitative Competetive Polymerase Chain Reaction Assay For The Detection And Quantitation Of Perkinsus Marinus In Oyster Tissues And Environmental Water Samples, Heather A. Yarnall
Dissertations, Theses, and Masters Projects
No abstract provided.
The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins
The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins
Dissertations, Theses, and Masters Projects
No abstract provided.
Development Of Supercritical Fluid Extraction (Sfe) For The Determination Of Polychlorinated Biphenyls In Tissues Of Aquatic Biota, Michael O. Gaylor
Development Of Supercritical Fluid Extraction (Sfe) For The Determination Of Polychlorinated Biphenyls In Tissues Of Aquatic Biota, Michael O. Gaylor
Dissertations, Theses, and Masters Projects
No abstract provided.
Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Nitrogen Based Ligands By Nmr Spectroscopy And X-Ray Crystallography, Rachel E. Freer
Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Nitrogen Based Ligands By Nmr Spectroscopy And X-Ray Crystallography, Rachel E. Freer
Dissertations, Theses, and Masters Projects
No abstract provided.
Spectroscopic Characterization Of Hg(Ii) Coordination Complexes, Sharon Rosemary Fitzhenry
Spectroscopic Characterization Of Hg(Ii) Coordination Complexes, Sharon Rosemary Fitzhenry
Dissertations, Theses, and Masters Projects
No abstract provided.
Direct Determination Of Trace Metals In Saline Water Samples Using Gfaas, Michael Joseph Wassell
Direct Determination Of Trace Metals In Saline Water Samples Using Gfaas, Michael Joseph Wassell
Dissertations, Theses, and Masters Projects
No abstract provided.
A Helium Discharge Detector For The Determination Of Organosulfur And Phosphorus Compounds, Tamara L. Tieman
A Helium Discharge Detector For The Determination Of Organosulfur And Phosphorus Compounds, Tamara L. Tieman
Dissertations, Theses, and Masters Projects
No abstract provided.
Evaluation Of A Technique To Quantify Lipids In Bivalve Larvae Crassostrea Virginica Gmelin, Using Nile Red And Epiflourescence Microscopy, Laura Liliana Castell Perez
Evaluation Of A Technique To Quantify Lipids In Bivalve Larvae Crassostrea Virginica Gmelin, Using Nile Red And Epiflourescence Microscopy, Laura Liliana Castell Perez
Dissertations, Theses, and Masters Projects
No abstract provided.
Dielectric Monitoring Of The Chemical, Rheological, And Morphological Changes Incurred During Cure Of Epoxide-Amine Systems, Dara Elyn Levy
Dielectric Monitoring Of The Chemical, Rheological, And Morphological Changes Incurred During Cure Of Epoxide-Amine Systems, Dara Elyn Levy
Dissertations, Theses, and Masters Projects
No abstract provided.
Evaluation Of Scavenger Gases In A Helium Discharge Detector, Sandra Lynn Poteat
Evaluation Of Scavenger Gases In A Helium Discharge Detector, Sandra Lynn Poteat
Dissertations, Theses, and Masters Projects
No abstract provided.