Chemistry Commons^™

Observations Of Greenhouse Gas Isotopologues With Ace-Fts And Waccm, Eric Michael Buzan

Chemistry & Biochemistry Theses & Dissertations

Increases in greenhouse gas concentrations in the atmosphere are the major driver of climate change. Quantifying the sources and sinks of these gases is a major focus of research. Measuring isotopologues, or molecules that differ in isotopic composition, is one useful way of constraining the budget of a molecule as they are highly sensitive to different sources and sinks. However, measurements above the surface have been restricted to a few locations and have only reached the lower stratosphere. Satellite-based remote sensing can achieve nearly global measurement coverage, but so far no satellites have measured isotopologues.

Presented here are measurements of …

Source-Specific Molecular Signatures For Light-Absorbing Organic Aerosols, Amanda Susan Willoughby

Chemistry & Biochemistry Theses & Dissertations

Organic aerosols (OA) are universally regarded as an important component of the atmosphere based on quantitative significance as well as the far-reaching impact they have on global climate forcing and human health. Despite the acknowledged importance, OA amounts and impacts remain the largest uncertainties regarding radiative forcing estimates. Incomplete chemical characterization of aerosol organic matter (OM) and a lack of concrete source apportionment is a major source of this uncertainty. The primary focus of this study is to provide much needed molecular details regarding ambient OA from key emission sources, and establish links between molecular and optical properties.

Complete chemical …

A Diffuse Reflectance Infrared Fourier Transform Spectroscopic Investigation Of The Oxidation Of Co On Platinum/Tin(Iv) Oxide-Based Catalysts, Julie Christi Stiltner Patrick

Chemistry & Biochemistry Theses & Dissertations

Platinum/tin(IV) oxide-based catalysts have been developed for the oxidation of carbon monoxide at 55 °C and 1 atmosphere pressure. A diffuse reflectance infrared fourier transform spectroscopic (DRIFTS) investigation of this oxidation has been performed. Four catalyst samples have been subjected to a 5% carbon monoxide pretreatment at 125 °C, helium exposure at 55 °C, bottled air (20% oxygen) exposure at 55 °c, and exposure to a 2:1 stoichiometric mixture of carbon monoxide and oxygen at 55 °C. During the course of these exposures, evidence for the development of two different surface carbon monoxide configurations has been found: one that is …

Optimization Of The Tungstic Acid Denuder Technique For The Measurement Of Atmospheric Ammonia, Patricia Diane Roberts

Chemistry & Biochemistry Theses & Dissertations

Measurement of - atmospheric ammonia with the tungstic acid denuder technique is discussed. Characterization of denuder tubes for manual sampling in terms of, repeatability, reliability and the development of ammonia blank signals was determined. Field testing of the manual sampling apparatus was performed at ground test sites and in a biomass burn smoke plume. Ammonia emissions from biomass burning are discussed.