The focus of this dissertation is the use of chromatographic methods coupled with electrospray mass spectrometry (ES-MS) for the determination of both organic and inorganic compounds in aqueous solutions. The combination of liquid chromatography (LC) methods and ES-MS offers one of the foremost methods for determining compounds in complex aqueous solutions. In this work, LC-ES-MS methods are devised using ion exclusion chromatography, reversed phase chromatography, and ion exchange chromatography, as well as capillary electrophoresis (CE). For an aqueous sample, these LC-ES-MS and CE-ES-MS techniques require no sample preparation or analyte derivatization, which makes it possible to observe a wide variety of analytes as they exist in solution. The majority of this work focuses on the use of LC-ES-MS for the determination of unknown products and intermediates formed during electrochemical incineration (ECI), an experimental waste remediation process. This report contains a general introduction to the project and the general conclusions. Four chapters have been removed for separate processing. Titles are: Chapter 2: Determination of small carboxylic acids by ion exclusion chromatography with electrospray mass spectrometry; Chapter 3: Electrochemical incineration of benzoquinone in aqueous media using a quaternary metal oxide electrode in the absence of a soluble supporting electrolyte; Chapter 4: The …

Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

This study of the RAgSb{sub 2} series of compounds arose as part of an investigation of rare earth intermetallic compounds containing antimony with the rare earth in a position with tetragonal point symmetry. Materials with the rare earth in a position with tetragonal point symmetry frequently manifest strong anisotropies and rich complexity in the magnetic properties, and yet are simple enough to analyze. Antimony containing intermetallic compounds commonly possess low carrier densities and have only recently been the subject of study. Large single grain crystals were grown of the RAgSb{sub 2} (R=Y, La-Nd, Sm, Gd-Tm) series of compounds out of a high temperature solution. This method of crystal growth, commonly known as flux growth is a versatile method which takes advantage of the decreasing solubility of the target compound with decreasing temperature. Overall, the results of the crystal growth were impressive with the synthesis of single crystals of LaAgSb{sub 2} approaching one gram. However, the sample yield diminishes as the rare earth elements become smaller and heavier. Consequently, no crystals could be grown with R=Yb or Lu. Furthermore, EuAgSb{sub 2} could not be synthesized, likely due to the divalency of the Eu ion. For most of the RAgSb{sub 2} compounds, …

Chapter 1 of this thesis describes the various stages of tumor development and a multitude of diagnostic techniques used to detect cancer. Chapter 2 gives an overview of the aspects of hole burning spectroscopy important for its application to the study of cellular systems. Chapter 3 gives general descriptions of cellular organelles, structures, and physical properties that can serve as possible markers for the differentiation of normal and cancerous cells. Also described in Chapter 3 are the principles of cryobiology important for low temperature spectroscopy of cells, characterization of MCF-10F (normal) and MCF-7 (cancer) cells lines which will serve as model systems, and cellular characteristics of aluminum phthalocyanine tetrasulfonate (APT), which was used as the test probe. Chapters 4 and 5 are previously published papers by the author pertaining to the results obtained from the application of hole burning to the study of cellular systems. Chapter 4 presents the first results obtained by spectral hole burning of cellular systems and Chapter 5 gives results for the differentiation of MCF-10F and MCF-7 cells stained with APT by an external applied electric (Stark) field. A general conclusion is presented in Chapter 6. Appendices A and B provide additional characterization of the cell/probe …

Methyltrioxorhenium (MTO) catalyzes the desulfurization of thiiranes by triphenylphosphine. Enormous enhancement in rate is observed when the catalyst is pretreated with hydrogen sulfide prior to the reaction. Using 2-mercaptomethylthiophenol as a ligand, the author synthesized several model complexes to study the mechanism of this reaction. With suitable model systems, they were able to show that the active catalyst is a Re(V) species. The reactions are highly stereospecific and very tolerant to functional groups. As part of the studies, he synthesized and crystallographically characterized the first examples of neutral terminal and bridging Re(V)sulfidocomplexes. Some of these complexes undergo fast oxygen atom transfer reactions with organic and inorganic oxidants. Studies on these model complexes led them to the discovery that MTO catalyzes the selective oxidation of thiols to disulfides. This report contains the Introduction; ``Chapter 6: Isomerization of Propargylic Alcohols to Enones and Enals Catalyzed by Methylrhenium Trioxide``; and Conclusions.

Net proton (proton minus antiproton) and negative charge hadron spectra (h-) from central Pb+Pb collisions at 158 GeV per nucleon at the CERN Super Proton Synchrotron were measured and compared to spectra from central collisions of the lighter S+S system. Net baryon distributions were derived from those of net protons and net lambdas. Stopping, or rapidity shift with respect to the beam, of net protons and net baryons increase with system size. The mean transverse momentum &60;pT&62; of net protons also increase with system size. The h- rapidity density scales with the number of participant nucleons for nuclear collisions, where their &60;pT&62; is independent of system size. The &60;pT&62; dependence upon particle mass and system size is consistent with larger transverse flow velocity at midrapidity for central collisions of Pb+Pb compared to that of S+S.

The author discusses the photodissociation of light elements due to the radiative decay of a massive particle, and he has shown how to constrain the model parameters from the observed light-element abundances. He adopted two quasar absorption system (QAS) D/H values, as well as solar system data for D/H and {sup 3}He/H. For each of these, he used two {sup 4}He values. He presents his results in terms of the confidence level at which each theoretical parameter set (i.e., the set of properties of a radiatively decaying particle) is excluded by the observed abundances. His algorithm for computing the confidence level is consistent and general enough to apply not only to the scenarios investigated in this work, but also to many other non-standard theories of BBN.

Inductively coupled plasma mass spectrometry (ICP-MS) has become the method of choice for elemental and isotopic analysis. Several factors contribute to its success. Modern instruments are capable of routine analysis at part per trillion levels with relative detection limits in part per quadrillion levels. Sensitivities in these instruments can be as high as 200 million counts per second per part per million with linear dynamic ranges up to eight orders of magnitude. With standards for only a few elements, rapid semiquantitative analysis of over 70 elements in an individual sample can be performed. Less than 20 years after its inception ICP-MS has shown to be applicable to several areas of science. These include geochemistry, the nuclear industry, environmental chemistry, clinical chemistry, the semiconductor industry, and forensic chemistry. In this introduction, the general attributes of ICP-MS will be discussed in terms of instrumentation and sample introduction. The advantages and disadvantages of current systems are presented. A detailed description of one method of sample introduction, laser ablation, is given. The paper also gives conclusions and suggestions for future work. Chapter 2, Quantitative analysis of solids by laser ablation inductively coupled plasma mass spectrometry using dried solution aerosols for calibration, has been removed …

Addition of a novel anionic surfactant, namely lauryl polyoxyethylene sulfate, to an aqueous-acetonitrile electrolyte makes it possible to separate nonionic organic compounds by capillary electrophoresis. Separation is based on differences in the association between analytes and the surfactant. Highly hydrophobic compounds such as polyaromatic hydrocarbons are well separated by this new surfactant. Migration times of analytes can be readily changed over an unusually large range by varying the additive concentration and the proportion of acetonitrile in the electrolyte. Several examples are given, including the separation of four methylbenz[a]anthracene isomers and the separation of normal and deuterated acetophenone. The effect of adding this new surfactant to the acidic electrolyte was also investigated. Incorporation of cetyltrimethylammonium bromide in the electrolyte is shown to dynamically coat the capillary and reverse electroosmotic flow. Chiral recognition mechanism is studied using novel synthetic surfactants as chiral selectors, which are made from amino acids reacting with alkyl chloroformates. A satisfactory separation of both inorganic and organic anions is obtained using electrolyte solutions as high as 5 M sodium chloride using direct photometric detection. The effect of various salts on electrophoretic and electroosmotic mobility is further discussed. Several examples are given under high-salt conditions.

The peak profile of individual degranulation events from the on-column release of serotonin from single rat peritoneal mast cells (RPMCs) was monitored using capillary electrophoresis with laser-induced native fluorescence detection (CE-LINF). Serotonin, an important biogenic amine, is contained in granules (0.25 fL) within RPMCs and is extruded by a process termed exocytosis. The secretagogue, Polymyxin B sulfate, was used as the CE running buffer after injection of a single RPMC into the separation capillary to stimulate the release of the granules. Because the release process occurs on a ms time scale, monitoring individual exocytotic events is possible with the coupling of high-speed CE and LINF detection.

Measurements of electrical resistivity as a function of temperature from 25 to 1,500 C were conducted on polycrystalline samples in the Mo-Si-B system. Single phase, or nearly single phase, samples were prepared for the following phases: Mo{sub 3}Si, Mo{sub 5}SiB{sub 2}, Mo{sub 5}Si{sub 3}B{sub x}, MoB, MoSi{sub 2}, and Mo{sub 5}Si{sub 3}. Thesis materials all exhibit resistivity values within a narrow range(4--22 x 10{sup {minus}7}{Omega}-m), and the low magnitude suggests these materials are semi-metals or low density of states metals. With the exception of MoSi{sub 2}, all single phase materials in this study were also found to have low temperature coefficient of resistivity(TCR) values. These values ranged from 2.10 x 10{sup {minus}10} to 4.74 x 10{sup {minus}10}{Omega}-m/{degree} C, and MoSi{sub 2} had a TCR of 13.77 x 10{sup {minus}10}{Omega}-m/{degree} C. The results from the single phase sample measurements were employed in a natural log rule-of-mixtures model to relate the individual phase resistivity values to those of multiphase composites. Three Mo-Si-B phase regions were analyzed: the binary Mo{sub 5}Si{sub 3}-MoSi{sub 2} system, the ternary phase field Mo{sub 5}Si{sub 3}B{sub x}MoB-MoSi{sub 2}, and the Mo{sub 3}Si-Mo{sub 5}SiB{sub 2}-Mo{sub 5} Si{sub 3}B{sub x} ternary region. The experimental data for samples in each of …

This research explores the application of a new technique, termed electrochemically modulated liquid chromatography (EMLC), to the chiral separations of pharmaceutical compounds. The introduction section provides a literature review of the technique and its applications, as well as brief overview of the research described in each of the next two chapters. Chapter 2 investigates the EMLC-based enantiomeric separation of a group of chiral benzodiazepines with {beta}-cyclodextrin as a chiral mobile phase additive. Chapter 3 demonstrates the effects of several experimental parameters on the separation efficiency of drug enantiomers. The author concludes with a general summary and possible directions for future studies. Chapters 2 and 3 are processed separately.

This report summarized the four parts of the research study and describes the general conclusions. Individual chapters have been removed for separate processing. The chapter titles are: A study of the dissociation of CH{sub 3}SH{sup +} by collisional activation: Observation of non-statistical behavior; High resolution vacuum ultraviolet pulsed field ionization photoelectron band for OCS{sup +}(X{sup 2}{Pi}): An experimental and theoretical study; Rotationally resolved pulsed field ionization photoelectron bands of H{sub 2}{sup +} ({Chi}{sup 2}{Sigma}{sup +}{sub g}, v{sup +} = 0--18); and Rotationally resolved pulsed field ionization photoelectron bands of HD{sup +} ({Chi}{sup 2}{Sigma}{sup +}, v{sup +} = 0--21).

The study of thermoelectric phenomena in solids provides a wealth of opportunity for exploration of the complex interrelationships between structure, processing, and properties of materials. As thermoelectricity implies some type of coupled thermal and electrical behavior, it is expected that a basic understanding of transport behavior in materials is the goal of such a study. However, transport properties such as electrical resistivity and thermal diffusivity cannot be fully understood and interpreted without first developing an understanding of the material's preparation and its underlying structure. It is the objective of this dissertation to critically examine a number of diverse systems in order to develop a broad perspective on how structure-processing-property relationships differ from system to system, and to discover the common parameters upon which any good thermoelectric material is based. The alloy systems examined in this work include silicon-germanium, zinc oxide, complex intermetallic compounds such as the half-Heusler MNiSn, where M = Ti, Zr, or Hf, and rare earth chalcogenides.

Crenulative turbulence is a nonlinear extension of the Bell-Plesset instability, usually observed in a converging system in which there is a nonhomogeneous response of stress to strain and/or strain rate. In general, crenelation occurs in any circumstance in which the mean flow streamlines converge the material more strongly than the compressibility can accommodate. Elements of the material slip past each other, resulting in local fluctuations in velocity from that of the mean flow, producing a type of turbulence that is more kinematic than inertial. For a homogeneous material, crenelation occurs at the atomic or molecular scale. With nonhomogeneous stress response at larger scales, the crenulative process can also occur at those larger scales. The results are manifested by a decrease in the rate of dissipation to heat, and by the configurationally-irreversible mixing of nonhomogeneities across any mean-flow-transported interface. We obtain a mathematical description of the crenulative process by means of Reynolds decomposition of the appropriate variables, and the derivation of transport equations for the second-order moments that arise in the mean-flow momentum and energy equations. The theory is illustrated by application to the spherical convergence of an incompressible fluid with nonhomogeneous distribution of kinematic viscosity.

Yucca Mountain, Nevada has been chosen as a possible site for the first high level radioactive waste repository in the United States. As part of the site investigation studies, we need to make scientifically rigorous estimations of radionuclide migration in the event of a repository breach. Performance assessment models used to make these estimations are computationally intensive. We have developed two reactive transport modeling techniques to simulate radionuclide transport at Yucca Mountain: (1) the selective coupling approach applied to the convection-dispersion-reaction (CDR) model and (2) a reactive stream tube approach (RST). These models were designed to capture the important processes that influence radionuclide migration while being computationally efficient. The conventional method of modeling reactive transport models is to solve a coupled set of multi-dimensional partial differential equations for the relevant chemical components in the system. We have developed an iterative solution technique, denoted the selective coupling method, that represents a versatile alternative to traditional uncoupled iterative techniques and the filly coupled global implicit method. We show that selective coupling results in computational and memory savings relative to these approaches. We develop RST as an alternative to the CDR method for solving large two- or three-dimensional reactive transport simulations for cases …

By definition a plasma is an electrically conducting gaseous mixture containing a significant concentration of cations and electrons. The Inductively Coupled Plasma (ICP) is an electrodeless discharge in a gas at atmospheric pressure. This discharge is an excellent one for vaporizing, atomizing, and ionizing elements. The early development of the ICP began in 1942 by Babat and then by Reed in the early 1960s. This was then followed by the pioneering work of Fassel and coworkers in the late 1960s. Commercial ICP spectrometers were introduced in the mid 1970s. A major breakthrough in the area of ICP took place in the early 1980s when the ICP was shown to be an excellent ion source for mass spectrometry.

The objective of this work was to investigate and develop a magnetomechanical material with high magnetomechanical response and low hysteresis. This material will be used in electronic torque sensors for advanced steering systems in automobiles which will replace the costly and fuel inefficient hydraulic steering systems currently in use. Magnetostruction and the magnetomechanical effect under torsional stress of magnetostrictive composites have been investigated in the present study.

Time resolved dynamics of high intensity laser interactions with atomic clusters have been studied with both theoretical analysis and experiment. A short-pulse Ti:sapphire laser system, which could produce 50 mJ of energy in a 50 fs pulse, was built to perform these experiments. The laser used a novel single grating stretcher and was pumped, in part, by a custom Nd:YLF laser system, including 19 mm Nd:YLF amplifiers. It was found that there is an optimal pulse width to maximize absorption for a given cluster size. This optimal pulse width ranged from 400 fs for 85 A radius xenon clusters to 1.2 ps for 205 {angstrom} radius xenon clusters. Using a pump-probe configuration, the absorption of the probe radiation was observed to reach a maximum for a particular time delay between pump and probe, dependent on the cluster size. The delay for peak absorption was 800, 1400, and 2100 fs for 85 {angstrom}, 130 {angstrom}, and 170 {angstrom} radius xenon clusters respectively. Model calculations suggest that these effects are due to resonant heating of the spherical plasma in agreement with the hydrodynamic interpretation of cluster interactions. While this simple hydrodynamic code produces reasonable agreement with data, it does not include bulk …

In chapter 1 the author reviews some elements of string theory relevant to the rest of this report. He touches on both the classical, i.e. perturbative, string physics before D-branes rise to prominence, and some of the progresses they brought forth. In chapter 2 he proceeds to give an exact algebraic formulation of D-branes in curved spaces. This allows one to classify them in backgrounds of interest and study their geometric properties. He applies this formalism to string theory on Calabi-Yau and other supersymmetry preserving manifolds. Then he studies the behavior of the D-branes under mirror symmetry in chapter 3. Mirror symmetry is known to be a symmetry of string theory perturbatively. He finds evidence for its nonperturbative validity when D-branes are also considered and compute some dynamical consequences. In chapter 4 he turns to examine the consistency of curved and/or intersecting D-brane configurations. They have been used recently to extract information about the field theories that arise in certain limits. It turns out that there are potential quantum mechanical inconsistencies associated with them. What saves the day are certain subtle topological properties of D-branes. This resolution has implications for the conserved charges carried by the D-branes, which he computes …

The effect of process parameters and chemical additives on the specific cake resistance of zinc hydroxide precipitates was investigated. The ability of a slurry to be filtered is dependent upon the particle habit of the solid and the particle habit is influenced by certain process variables. The process variables studied include neutralization temperature, agitation type, and alkalinity source used for neutralization. Several commercially available chemical additives advertised to aid in solid/liquid separation were also examined in conjunction with hydroxide precipitation. A statistical analysis revealed that the neutralization temperature and the source of alkalinity were statistically significant in influencing the specific cake resistance of zinc hydroxide precipitates in this study. The type of agitation did not significantly effect the specific cake resistance of zinc hydroxide precipitates. The use of chemical additives in conjunction with hydroxide precipitation had a favorable effect on the filterability. The morphology of the hydroxide precipitates was analyzed using scanning electron microscopy.

Partial transient liquid phase (PTLP) bonding is a technique which can be used to join ceramics with metals and is used to form niobium-based joints for alumina. The principal advantage to PTLP bonding is that it enables refractory joints to be fabricated at temperatures below those typically required by solid state diffusion bonding. A thorough review of the important parameters (chemical compatibility, thermal expansion match, sufficient wettability of the liquid phase on the solid phases) in choosing a joining material for ceramics by the PTLP method is provided. As in conventional PTLP joining, the current study uses thin (=3 (mu)m) copper layers sandwiched between the alumina (bulk) and niobium (127 (mu)m). However, unlike the case of copper/nickel/copper obium is limited. Consequently, the copper is not entirely dissolved in the process, resulting in a two phase (copper-rich and niobium-rich phases) microstructure. Different processing conditions (temperature and applied load) result in different morphologies of the copper-rich and niobium-rich phases at the interface. These different microstructures exhibit distinct strength characteristics. Extended annealing of as-processed joints can influence the strengths differently depending on the ambient partial oxygen pressure at the annealing temperature. The focus of this work is to correlate processing conditions, microstructure, and …

This dissertation presented several results which add to the general knowledge base regarding organothiolates monolayer spontaneously adsorbed at gold films. Common to the body of this work is the use of voltammetric reductive resorption and variants of scanning probe microscopy to gain insight into the nature of the monolayer formation process as well as the resulting interface. The most significant result from this work is the success of using friction force microscopy to discriminate the end group orientation of monolayer chemisorbed at smooth gold surfaces with micrometer resolution (Chapter 4). The ability to detect the differences in the orientational disposition is demonstrated by the use PDMS polymer stamp to microcontact print an adlayer of n-alkanethiolate of length n in a predefine pattern onto a gold surface, followed by the solution deposition of a n-alkanethiol of n {+-} 1 to fill in the areas on the gold surface intentionally not coated by the stamping process. These two-component monolayers can be discriminated by using friction force microscopy which detects differences in friction contributed by the differences in the orientation of the terminal groups at surfaces. This success has recently led to the detection of the orientation differences at nanometer scale. Although the …

A methodology that can monitor and identify inorganic elements in biological and environmental systems was developed. Size exclusion chromatography (SEC) separates biomolecules, which are then nebulized by a microconcentric nebulizer. The resulting aerosol is desolved and introduced into either a high resolution ICP-MS device or a quadrupole device with a collision cell. Because of the high sensitivity and spectral resolution and high sample introduction efficiency, many unusual or difficult elements, such as Cr, Se, Cd and U, can be observed at ambient levels bound to proteins in human serum. These measurements are made in only a few minutes without preliminary isolation and preconcentration steps. Serum samples can be titrated with spikes of various elements to determine which proteins bind a given metal and oxidation state. Experiments concerning the effects of breaking disulfide linkages and denaturation on metal binding in proteins were also investigated. Elemental distribution in liver extract was also obtained.