Two studies were conducted involving rare earth elements. In the
first study, the use of rare earth diethylenetriaminepentaacetic acid
(DTPA) complexes as stable actiable tracers, a method of stable-isotope
tracing with post-sampling neutron activation analysis, was explored.
The persistence of rare earth DTPA complexes in estuarine waters was
measured in...
In this dissertation, the structural properties, thermodynamics and defect behavior of amorphous metal oxides and polyoxometalates are studied. Amorphous metal oxides have many applications, most notably as a semiconducting material used as the active matrix of thin film transistors. Alas, the amorphous nature of these materials makes studying them rather...
Water is an absolute necessity for life as we know it. It provides a useful medium in which chemical reactions take place that allowed for the development of single cellular organisms. When combined with the evolutionary accident that was pho- tosynthesis, water became not only a useful medium chemical reactions,...
Uranyl peroxide clusters are the newest family of polyoxometalates, discovered in 2015. Although this family is new, over 70 topologies have been reported. However, we lack the fundamental understanding of assembly mechanisms, particularly the role of the alkali countercations. Here, we use a wide range of solution and solid-state characterization...
A nonflame method for atomic absorption spectroscopy is
described. A helical tungsten filament from a commercially available
6-V, 4-A light bulb, heated to :incandescence in an argon atmosphere
is used to atomize 2-μl aqueous samples for metals analyses. Studies
of two hollow cathode lamp tungsten filament orientations, a
modulated light...
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants formed from the incomplete combustion of organic material. These contaminants are of concern because of their widespread presence in the environment and toxic properties. In addition, PAHs encompass a class of diverse compounds with varying physicochemical properties and exist in the environment as...
In this report, three studies are presented that utilize computations to predict transformations, identities, and properties of environmental organic molecules. Each study shows how computations can lead to models of chemical behavior. The importance of this research is rooted in the need for understanding how human behavior and health intersect...
In this report, two studies are presented that utilize computations to predict and elucidate the reaction mechanisms of two different copper catalyzed reactions. Each study provides insight into the various chemical transformations, as well as the how and why behind regioselectivity and isotopic selectivity. The importance of this research is...
In this dissertation, the spectroscopic properties and thermodynamic stability of a class of materials known as metal oxo and hydroxo clusters are studied. In aqueous solutions, many metals can aggregate into discrete clusters of metals bridged by oxo or hydroxo ligands. These clusters are of particular interest to us for...
A molecular approach to metal oxides allows to the study to fundamental bonding and formation behavior for such metals. Moreover, the molecular nature of such oxides or metal-oxo clusters allows the possibility of exploitation of the properties of the parent oxides. The tetravalent metals, in specific, (M=Zr, Hf, Ce, Th,...
Eleven hand specimen whole rock (WR) samples (25-200 g each) and
33 fragments (0.5-0.8 g each) from a single basaltic flow at Picture
Gorge, Oregon were analyzed via instrumental neutron activation
analysis (INAA) for 12 elements (Na, Fe, Cr, Sc, Co, La, Sm, Eu, Yb,
Lu, Hf and Ta). Standard...
As scientists, we have an affinity for order: repeating crystal structures, Euclidean space, continuous functions… Even concepts such as defects are discussed in the context of distracting from order. Things are most logical and best described in straightforward, taxonomical fashion. But what happens when the very application desired is dependent...
Studies of anisotropic and isotropic Raman line shape yield information about the rotational motion (rotational correlation function) and non-reorientational (vibrational) lifetimes. The rotational motion of carbon disulfide has been studied previously by the techniques of Raman spectroscopy (6, 43), Rayleigh scattering (43, 46) and direct measurement (47). This work was...
Due to its importance, the phenomenon of hydrogen
bonding has been the subject of much research over the
years. Among the different techniques used to study
hydrogen bonded systems, vibrational spectroscopy is
perhaps the most sensitive because of the striking
changes induced in molecular spectra by the formation of
hydrogen...
High-resolution mass spectrometry was used to measure a range of volatile organic compounds (VOCs) in real time as they were produced by the ubiquitous marine cyanobacterium Synechococcus WH8102 during a 24-hour light/dark cycle. Ethenone, acetaldehyde, ethanol, isoprene, acetic acid, dimethyl sulfide (DMS), acetone, phenol, and several as-yet unidentified compounds were...
Water and methanol adsorption isotherms at 25° and 37° C.
were determined on a series of organo-bentonite clays. The clays
differed in the length of the carbon chain attached to the amine adsorbed
in the cation exchange position. The amines used had carbon
chains of 4, 6, 8, 10, 12,...
The work presented here is focused on applying basic principles of solid-state chemistry to the study and development of new wide band-gap semiconductors and insulators for photovoltaic and electronic-device applications. Analysis of crystal structure, band structure, optical band gap, morphology and transport properties provides fundamental insight into materials performance as...
This thesis consists of an autoethnography of a sexual assault survivor written using poems, journal entries, annotations, photographs and song lyrics. The ethnography is a chronological record of feelings the author experienced during the day prior to the attack and emotions she navigated during the year and a half after...
The core-electron ionization potentials for mono- and
di(trifluoromethyl)benzene, for chlorofluoromethanes and for
chlorine have been measured in order to give information on
the electron distribution in these molecules and to investigate
differences between the inductive effect of fluorine
and that of CF3. For trifluoromethylbenzene the measured
ionization potentials in eV...
Lamellar x-ray diffraction was studied from thin films of L-α-1,2-dipalmitoyl lecithin (DPL) and a 1:1 mixture (BrDPL) of L-α-l-palmitoyl-2-(9- bromopaimitoyl) lecithin and its 10-bromo analog. The specimens had high lamellar order, with an upper bound on the mosaicity of 6 mrad (0.4°) for DPL and BrDPL. With various water contents,...
In this dissertation, I present electronic spectra of a few polycyclic aromatic hydrocarbons (PAHs): tetracene, pentacene, pyrene, benzo[g,h,i]perylene and benzo[a]pyrene using resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The work of tetracene and pentacene also combine a laser desorption source with a ZEKE spectrometer, demonstrating...
In this dissertation, I describe spectroscopic studies of jet-cooled polycyclic aromatic hydrocarbons (PAH) and one nitrogen substituted PAH (PANH) using pulsed field zero kinetic energy (ZEKE) photoelectron spectroscopy and resonantly enhanced multiphoton ionization (REMPI) spectroscopy. Recently, there has been a demand for far-infrared (FIR) spectral information of astrophysically relevant molecules...