The Pacific Northwest National Laboratory (PNNL) operates a number of research and development (R&D) facilities for the U.S. Department of Energy at the Hanford Site, Washington. These facilities are subject to Clean Air Act regulations that require sampling of radionuclide air emissions from some of these facilities. A revision to an American National Standards Institute (ANSI) standard on sampling radioactive air emissions has recently been incorporated into federal and state regulations and a re-evaluation of affected facilities is being performed to determine the impact. The revised standard requires a well-mixed sampling location that must be demonstrated through tests specified in the standard. It also carries a number of maintenance requirements, including inspections and cleaning of the sampling system. Evaluations were performed in 2000 – 2002 on two PNNL facilities to determine the operational and design impacts of the new requirements. The evaluation included inspection and cleaning maintenance activities plus testing to determine if the current sampling locations meet criteria in the revised standard. Results show a wide range of complexity in inspection and cleaning activities depending on accessibility of the system, ease of removal, and potential impact on building operations (need for outages). As expected, these High Efficiency Particulate Air …

In Part 1, geometric clusters of the Ising model are studied as possible model clusters for nuclear multifragmentation. These clusters may not be considered as non-interacting (ideal gas) due to excluded volume effect which predominantly is the artifact of the cluster's finite size. Interaction significantly complicates the use of clusters in the analysis of thermodynamic systems. Stillinger's theory is used as a basis for the analysis, which within the RFL (Reiss, Frisch, Lebowitz) fluid-of-spheres approximation produces a prediction for cluster concentrations well obeyed by geometric clusters of the Ising model. If thermodynamic condition of phase coexistence is met, these concentrations can be incorporated into a differential equation procedure of moderate complexity to elucidate the liquid-vapor phase diagram of the system with cluster interaction included. The drawback of increased complexity is outweighted by the reward of greater accuracy of the phase diagram, as it is demonstrated by the Ising model. A novel nuclear-cluster analysis procedure is developed by modifying Fisher's model to contain cluster interaction and employing the differential equation procedure to obtain thermodynamic variables. With this procedure applied to geometric clusters, the guidelines are developed to look for excluded volume effect in nuclear multifragmentation. In part 2, an explanation is …

One and two dimensional time-resolved vibrational spectroscopy has been used to investigate the elementary reactions of several prototypical organometallic complexes in room temperature solution. The electron transfer and ligand substitution reactions of photogenerated 17-electron organometallic radicals CpW(CO){sub 3} and CpFe(CO){sub 2} have been examined with one dimensional spectroscopy on the picosecond through microsecond time-scales, revealing the importance of caging effects and odd-electron intermediates in these reactions. Similarly, an investigation of the photophysics of the simple Fischer carbene complex Cr(CO){sub 5}[CMe(OMe)] showed that this class of molecule undergoes an unusual molecular rearrangement on the picosecond time-scale, briefly forming a metal-ketene complex. Although time-resolved spectroscopy has long been used for these types of photoinitiated reactions, the advent of two dimensional vibrational spectroscopy (2D-IR) opens the possibility to examine the ultrafast dynamics of molecules under thermal equilibrium conditions. Using this method, the picosecond fluxional rearrangements of the model metal carbonyl Fe(CO){sub 5} have been examined, revealing the mechanism, time-scale, and transition state of the fluxional reaction. The success of this experiment demonstrates that 2D-IR is a powerful technique to examine the thermally-driven, ultrafast rearrangements of organometallic molecules in solution.

The realization of tunable, ultrashort pulse x-ray sources promises to open new venues of science and to shed new light on long-standing problems in condensed matter physics and chemistry. Fundamentally new information can now be accessed. Used in a pump-probe spectroscopy, ultrashort x-ray pulses provide a means to monitor atomic rearrangement and changes in electronic structure in condensed-matter and chemical systems on the physically-limiting time-scales of atomic motion. This opens the way for the study of fast structural dynamics and the role they play in phase transitions, chemical reactions and the emergence of exotic properties in materials with strongly interacting degrees of freedom. The ultrashort pulse x-ray source developed at the Advanced Light Source at the Lawrence Berkeley Laboratory is based on electron slicing in storage rings, and generates {approx}100 femtosecond pulses of synchrotron radiation spanning wavelengths from the far-infrared to the hard x-ray region of the electromagnetic spectrum. The tunability of the source allows for the adaptation of a broad range of static x-ray spectroscopies to useful pump-probe measurements. Initial experiments are attempted on transition metal complexes that exhibit relatively large structural changes upon photo-excitation and which have excited-state evolution determined by strongly interacting structural, electronic and magnetic degrees …

The authors report on a search for the decay B{sup {+-}} {yields} D{sub s}{sup (*){+-}} {phi} using 212.2 fb{sup -1} of data collected with the BABAR detector at the PEP-II B Factory at the Stanford Linear Accelerator Center between 1999 and 2004. This sample of 234 x 10{sup 6} e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} events yields no significant signal. They report the Bayesian upper limits {Beta}(B{sup {+-}} {yields} D{sub s}{sup {+-}} {phi}) x {Beta}(D{sub s}{sup {+-}} {yields} {phi}{pi}{sup {+-}}) < 8.6 x 10{sup -8} and {Beta}(B{sup {+-}} {yields} D*{sub s}{sup {+-}}{phi}) x {Beta}(D{sub s}{sup {+-}} {yields} {phi}{pi}{sup {+-}}) < 5.4 x 10{sup -7} at the 90% C.L. Using the latest measurement of {Beta}(D{sub s}{sup {+-}} {yields} {phi}{pi}{sup {+-}}), they report: {Beta}(B{sup {+-}} {yields} D{sub s}{sup {+-}}{phi}) < 1.8 x 10{sup -6} and {Beta}(B{sup {+-}} {yields} D*{sub s}{sup {+-}}{phi}) < 1.1 x 10{sup -5} at the 90% C.L.

We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{sup 0}{bar B}{sup 0} decays collected between 1999 and 2004, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in {tau}{sup -} {yields} {omega}{pi}{sup -} {nu}{sub {tau}}. We also measure the polarization of the D*{sup +} as a function of the {omega}{pi}{sup -} mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*{sup +} to be {Lambda}{sub L}/{Lambda} = 0.654 {+-} 0.042(stat.) {+-} 0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as {bar B}{sup 0} {yields} D*{sup +} {rho}(1450){sup -}, {rho}(1450){sup -} {yields} {omega}{pi}{sup -}. Furthermore, we present the results on the time-dependent CP asymmetry in neutral B meson decays to …

Of the six quarks in the standard model the top quark is by far the heaviest: 35 times more massive than its partner the bottom quark and more than 130 times heavier than the average of the other five quarks. Its correspondingly small decay width means it tends to decay before forming a bound state. Of all quarks, therefore, the top is the least affected by quark confinement, behaving almost as a free quark. Its large mass also makes the top quark a key player in the realm of the postulated Higgs boson, whose coupling strengths to particles are proportional to their masses. Precision measurements of particle masses for e.g. the top quark and the W boson can hereby provide indirect constraints on the Higgs boson mass. Since in the standard model top quarks couple almost exclusively to bottom quarks (t {yields} Wb), top quark decays provide a window on the standard model through the direct measurement of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element V{sub tb}. In the same way any lack of top quark decays into W bosons could imply the existence of decay channels beyond the standard model, for example charged Higgs bosons as expected in two-doublet Higgs …

A search for the rare, flavour-changing neutral current decay B{sup +} {yields} K{sup +} {nu}{bar {nu}} is presented using 81.9 fb{sup -1} of data collected at the {Upsilon}(4S) resonance by the BABAR experiment. Signal candidate events are selected through the identification of a high momentum charged kaon and significant missing energy, where the companion B{sup -} in the event has decayed semileptonically via B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}} X and X is kinematically constrained to be either nothing or a low momentum transition photon or {pi}{sup 0}. The analysis was performed blind and 6 candidates were selected with a background expectation of 3.4 {+-} 1.2. This leads to a limit on the branching fraction of {Beta} (B{sup +} {yields} K{sup +} {nu}{bar {nu}}) < 7.2 x 10{sup -5} at 90% confidence level. We also search for the reaction B{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} and extract a limit on the branching fraction of {Beta}(B{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) < 2.5 x 10{sup -4} at 90% confidence level.

Inclusive transverse momentum spectra of photons and {pi}{sup 0}s at mid-rapidity are studied as a function of collision centrality for {sup 197}Au+ {sup 197}Au collisions at {radical}s{sub NN} = 130 GeV. Photon pair conversions have been reconstructed from charged tracks measured by the main Time Project Chamber of the STAR experiment at the RHIC heavy ion facility. The transverse momentum resolution of photons with this method is estimated to be {Delta}p{sub t}/p{sub t} = 2% at 0.125 GeV/c and 5% at 2.5 GeV/c. Photon spectra were measured up to a transverse momentum of 2.4 GeV/c between {+-} 0.5 units of rapidity. The dominant photon production mechanism, the {pi}{sup 0} {yields} {gamma}{gamma} decay, was measured between 0.25-2.5 GeV/c and {+-} 1 units of rapidity. Spectra are reported for the top 11%, 11-34% and 34-85% centrality classes. It was observed that in mid-central and central collisions the relative contribution of the {pi}{sup 0} {yields} {gamma}{gamma} decay to the inclusive photon spectrum decreases above a transverse momentum of 1.65 GeV/c. In central collisions the magnitude of the decrease from p{sub t} = 1.65 GeV/c to 2.4 GeV/c is 20%. It is unlikely that contributions from other {pi}{sup 0} decay channels and other particle …

High energy-density physics (HEDP) experiments examine the properties of materials under extreme conditions. These experiments rely on the measurement of one or two velocities. These velocities are used to obtain Hugoniot relationships and thermodynamic equations of state. This methodology is referred to as 'velocimetry' and an instrument used to measure the shock wave is called a 'velocimeter' or a '(velocity) diagnostic'. The two most-widely used existing velocity diagnostics are; photonic Doppler velocimetry (PDV) and velocity interferometer system for any reflector (VISAR). PDV's advantages are a fast rise-time and ease of implementation but PDV has an upper velocity limit. Traditional implementations of VISAR have a rise time 10 times slower than PDV and are not easily implemented but are capable of measuring any velocity produced during HEDP experiments. This thesis describes a novel method of combining the positive attributes of PDV and VISAR into a more cost effective diagnostic called a Single-Mode VISAR (SMV). The new diagnostic will consist of PDV parts in a VISAR configuration. This configuration will enable the measurement of any velocity produced during shock physics experiments while the components used to build the diagnostic will give the diagnostic a fast rise time and make it easy to …

This dissertation presents a simultaneous measurement of the branching fractions of ten B {yields} D{sup (*)}{bar D}{sup (*)} decays. The measurements are derived from a sample of 2.32 x 10{sup 8} B{bar B} pairs collected by the BABAR detector at the PEP-II B Factory located at Stanford Linear Accelerator Center. The branching fractions (x 10{sup -4}) are: -0.10 {+-} 0.44 {+-} 0.15 (<0.59) for B{sup 0} {yields} D{sup 0}{bar D}{sup 0}; 1.01 {+-} 1.07 {+-} 0.35 (<2.92) for B{sup 0} {yields} D*{sup 0}{bar D}{sup 0}; -1.31 {+-} 1.05 {+-} 0.41 (<0.92) for B{sup 0} {yields} D*{sup 0}{bar D}*{sup 0}; 2.81 {+-} 0.43 {+-} 0.45 for B{sup 0} {yields} D{sup +}D{sup -}; 5.72 {+-} 0.64 {+-} 0.71 for B{sup 0} {yields} D*{sup +}D{sup -}; 8.11 {+-} 0.57 {+-} 0.97 for B{sup 0} {yields} D*{sup +}D*{sup -}; 3.76 {+-} 0.57 {+-} 0.45 for B{sup -} {yields} D{sup -}D{sup 0}; 3.56 {+-} 0.52 {+-} 0.39 for B{sup -} {yields} D*{sup -}D{sup 0}; 6.30 {+-} 1.32 {+-} 0.93 for B{sup -} {yields} D{sup -}D*{sup 0}; and 8.14 {+-} 1.17 {+-} 1.11 for B{sup -} {yields} D*{sup -}D*{sup 0}. The first uncertainty is statistical while the second is systematic. The number in parentheses is the …

A process for the deposition of yttria stabilized zirconia (YSZ) films, on porous substrates, has been developed. These films have possible applications as electrolyte membranes in fuel cells. The films were deposited from colloidal suspensions through the vacuum infiltration technique. Films were deposited on both fully sintered and partially sintered substrates. A critical cracking thickness for the films was identified and strategies are presented to overcome this barrier. Green film density was also examined, and a method for improving green density by changing suspension pH and surfactant was developed. A dependence of film density on film thickness was observed, and materials interactions are suggested as a possible cause. Non-shorted YSZ films were obtained on co-fired substrates, and a cathode supported solid oxide fuel cell was constructed and characterized.

Experiments and direct numerical simulations have been performed to examine the effects of initial conditions on the dynamics of a Rayleigh-Taylor mixing layer. Experiments were performed on a water channel facility to quantify the interfacial and velocity perturbations initially present at the two-fluid interface in a small Atwood number mixing layer. The measurements have been parameterized for implementation in numerical simulations of the experiment, and two- and three-dimensional direct numerical simulations (DNS) of the experiment have been performed. It is shown that simulations implemented with initial velocity perturbations are required to match experimentally-measured statistics. Data acquired from both the experiment and numerical simulations are used to elucidate the role of initial conditions on the evolution of integral-scale, turbulence, and mixing statistics. Early-time turbulence and mixing statistics will be shown to be strongly dependent upon the early-time transition of the initial perturbation from a weakly- to a strongly-nonlinear flow.

As of the development of this thesis, no commercially available products have been identified for the digital communication of instrumented data across a thick ({approx} 6 n.) steel wall using ultrasound. The specific goal of the current research is to investigate the application of methods for digital communication of instrumented data (i.e., temperature, voltage, etc.) across the wall of a steel pressure vessel. The acoustic transmission of data using ultrasonic transducers prevents the need to breach the wall of such a pressure vessel which could ultimately affect its safety or lifespan, or void the homogeneity of an experiment under test. Actual digital communication paradigms are introduced and implemented for the successful dissemination of data across such a wall utilizing solely an acoustic ultrasonic link. The first, dubbed the ''single-hop'' configuration, can communicate bursts of digital data one-way across the wall using the Differential Binary Phase-Shift Keying (DBPSK) modulation technique as fast as 500 bps. The second, dubbed the ''double-hop'' configuration, transmits a carrier into the vessel, modulates it, and retransmits it externally. Using a pulsed carrier with Pulse Amplitude Modulation (PAM), this technique can communicate digital data as fast as 500 bps. Using a CW carrier, Least Mean-Squared (LMS) adaptive …

Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and quartz crystal microbalance (QCM) have been used to study the molecular surface structure, surface topography and mechanical properties, and quantitative adsorbed amount of biological molecules at the solid-liquid interface. The molecular-level behavior of designed peptides adsorbed on hydrophobic polystyrene and hydrophilic silica substrates has been examined as a model of protein adsorption on polymeric biomaterial surfaces. Proteins are such large and complex molecules that it is difficult to identify the features in their structure that lead to adsorption and interaction with solid surfaces. Designed peptides which possess secondary structure provide simple model systems for understanding protein adsorption. Depending on the amino acid sequence of a peptide, different secondary structures ({alpha}-helix and {beta}-sheet) can be induced at apolar (air/liquid or air/solid) interfaces. Having a well-defined secondary structure allows experiments to be carried out under controlled conditions, where it is possible to investigate the affects of peptide amino acid sequence and chain length, concentration, buffering effects, etc. on adsorbed peptide structure. The experiments presented in this dissertation demonstrate that SFG vibrational spectroscopy can be used to directly probe the interaction of adsorbing biomolecules with a surface or interface. The use of …

This work presents simultaneous branching fraction measurements of the decay modes {tau}{sup -} {yields} K{sup -} n{pi}{sup 0}{nu}{sub {tau}} with n = 0,1,2,3 and {tau}{sup -} {yields} {pi}{sup -} n{pi}{sup 0}{nu}{sub {tau}} with n = 3,4. The analysis is based on a data sample of 427 x 10{sup 6} {tau}{sup +}{tau}{sup -} pairs recorded with the BABAR detector, which corresponds to an integrated luminosity of 464.4 fb{sup -1}. The measured values are {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}}) = (6.57 {+-} 0.03 {+-} 0.11) x 10{sup -3}, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup 0}{nu}{sub {tau}}) = (4.61 {+-} 0.03 {+-} 0.11) x 10{sup -3}, {Beta}({tau}{sup -} {yields} K{sup -} {pi}{sup 0}{pi}{sup 0}{nu}{sub {tau}}) = (5.05 {+-} 0.17 {+-} 0.44) x 10{sup -4}, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup 0}{pi}{sup 0}{pi}{sup 0}{nu}{sub {tau}}) = (1.31 {+-} 0.43 {+-} 0.40) x 10{sup -4}, {Beta}({tau}{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0}{pi}{sup 0}{nu}{sub {tau}}) = (1.263 {+-} 0.008 {+-} 0.078) x 10{sup -2} and {Beta}({tau}{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0}{pi}{sup 0}{pi}{sup 0}{nu}{sub {tau}}) = (9.6 {+-} 0.5 {+-} 1.2) x 10{sup -4}, where the uncertainties are statistical and systematic, respectively. All measurements are compatible with the current world averages whereas the uncertainties are significantly smaller …

The authors present the results of a new measurement of the t{anti t} production cross section using e{mu} channel in p{anti p} collisions at {radical}s = 1.8 TeV. This study corresponds to an integrated luminosity of 108.3 {+-} 5.7 pb{sup {minus}1} acquired by the D0 detector during the Fermilab Tevatron Collider Run 1 (1992--1996). By using neural network techniques instead of the conventional analysis methods, the authors show that the signal acceptance can be increased by 10% (for m{sub t} = 172 GeV/c{sup 2}) while the background remains constant. Four e{mu} events are observed in data with an estimated background of 0.22 {+-} 0.14 corresponding to a t{anti t} production cross section of 9.75 {+-} 5.53 pb.

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Manganese model complexes, relevant to the oxygen-evolving complex (OEC) in photosynthesis, were studied with Mn K-edge X-ray absorption near-edge spectroscopy (XANES), Mn Kb X-ray emission spectroscopy (XES), and vibrational spectroscopy. A more detailed understanding was obtained of the influence of nuclearity, overall structure, oxidation state, and ligand environment of the Mn atoms on the spectra from these methods. This refined understanding is necessary for improving the interpretation of spectra of the OEC. Mn XANES and Kb XES were used to study a di-(mu)-oxo and a mono-(mu)-oxo di-nuclear Mn compound in the (III,III), (III,IV), and (IV,IV) oxidation states. XANES spectra show energy shifts of 0.8 - 2.2 eV for 1-electron oxidation-state changes and 0.4 - 1.8 eV for ligand-environment changes. The shifts observed for Mn XES spectra were approximately 0.21 eV for oxidation state-changes and only approximately 0.04 eV for ligand-environment changes. This indicates that Mn Kb XES i s more sensitive to the oxidation state and less sensitive to the ligand environment of the Mn atoms than XANES. These complimentary methods provide information about the oxidation state and the ligand environment of Mn atoms in model compounds and biological systems. A versatile spectroelectrochemical apparatus was designed to aid the interpretation …

The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence …