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Full-Text Articles in Chemistry
Evolution Of Selected Isoprene Oxidation Products In Dark Aqueous Ammonium Sulfate, D.M. Ashraf Ul Habib
Evolution Of Selected Isoprene Oxidation Products In Dark Aqueous Ammonium Sulfate, D.M. Ashraf Ul Habib
Dissertations, Master's Theses and Master's Reports - Open
The aqueous phase processing of glyoxylic acid, pyruvic acid, oxalic acid and methylglyoxal was studied simulating dark and radical free atmospheric aqueous aerosol. A novel observation of the cleavage of a carbon-carbon bond in pyruvic acid and glyoxylic acid leading to their decarboxylation was made in the presence of ammonium salts but no decarboxylation was observed from oxalic acid. The empirical rate constants for decarboxylation were determined. The structure of the acid, ionic environment of solution and concentration of species found to affect the decarboxylation process. A tentative set of reaction mechanisms was proposed involving nucleophilic attack by ammonia on …
Non-Chromatographic Purification Of Synthetic Bio-Oligomers, Durga Prasad Pokharel
Non-Chromatographic Purification Of Synthetic Bio-Oligomers, Durga Prasad Pokharel
Dissertations, Master's Theses and Master's Reports - Open
Synthetic oligonucleotides and peptides have found wide applications in industry and academic research labs. There are ~60 peptide drugs on the market and over 500 under development. The global annual sale of peptide drugs in 2010 was estimated to be $13 billion. There are three oligonucleotide-based drugs on market; among them, the FDA newly approved Kynamro was predicted to have a $100 million annual sale. The annual sale of oligonucleotides to academic labs was estimated to be $700 million. Both bio-oligomers are mostly synthesized on automated synthesizers using solid phase synthesis technology, in which nucleoside or amino acid monomers are …
Ionic Liquid Extraction Unveils Previously Occluded Humicbound Iron In Peat Porewater, Timothy J. Veverica
Ionic Liquid Extraction Unveils Previously Occluded Humicbound Iron In Peat Porewater, Timothy J. Veverica
Dissertations, Master's Theses and Master's Reports - Open
Extracellular iron reduction has been suggested as a candidate metabolic pathway that may explain a large proportion of carbon respiration in temperate peatlands. However, the o-phenanthroline colorimetric method commonly employed to quantitate iron and partition between redox species is known to be unreliable in the presence of humic and fulvic acids, both of which represent a considerable proportion of peatland dissolved organic matter. We propose ionic liquid extraction as a more accurate iron quantitation and redox speciation method in humic-rich peat porewater. We evaluated both o-phenanthroline and ionic liquid extraction in four distinct peatland systems spanning a gradient of physico-chemical …
Molecular Characterization Of Atmospheric Organic Matter In Biogenic Secondary Organic Aerosol, Ambient Aerosol And Clouds, Yunzhu Zhao
Dissertations, Master's Theses and Master's Reports - Open
Atmospheric aerosol affects the Earth’s energy budget, reduces visibility and influences human health. The organic composition of aerosol is quite complex and continuously evolves through various atmospheric processes. To gain a deeper understanding of the molecular composition of atmospheric organic matter (AOM), chamber-generated biogenic secondary organic aerosol (SOA), ambient aerosol and cloud water samples were studied. Ultrahigh resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry was used to provide detailed molecular characterization of the atmospheric samples. Due to the extremely high mass resolution and mass accuracy, thousands of individual molecular formulas were identified in all of the samples studied. Multivariate …
Design, Synthesis And Applications Of Fluorescent And Electrochemical Probes, Giri K. Vegesna
Design, Synthesis And Applications Of Fluorescent And Electrochemical Probes, Giri K. Vegesna
Dissertations, Master's Theses and Master's Reports - Open
“Seeing is believing” the proverb well suits for fluorescent imaging probes. Since we can selectively and sensitively visualize small biomolecules, organelles such as lysosomes, neutral molecules, metal ions, anions through cellular imaging, fluorescent probes can help shed light on the physiological and pathophysiological path ways. Since these biomolecules are produced in low concentrations in the biochemical pathways, general analytical techniques either fail to detect or are not sensitive enough to differentiate the relative concentrations. During my Ph.D. study, I exploited synthetic organic techniques to design and synthesize fluorescent probes with desirable properties such as high water solubility, high sensitivity and …
Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray
Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray
Dissertations, Master's Theses and Master's Reports - Open
This work presents a 1-D process scale model used to investigate the chemical dynamics and temporal variability of nitrogen oxides (NOx) and ozone (O3) within and above snowpack at Summit, Greenland for March-May 2009 and estimates surface exchange of NOx between the snowpack and surface layer in April-May 2009. The model assumes the surface of snowflakes have a Liquid Like Layer (LLL) where aqueous chemistry occurs and interacts with the interstitial air of the snowpack. Model parameters and initialization are physically and chemically representative of snowpack at Summit, Greenland and model results are compared to …