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open access

Ag on Si(111) from basic science to application

Description: In our work we revisit Ag and Au adsorbates on Si(111)-7x7, as well as experiment with a ternary system of Pentacene, Ag and Si(111). Of particular interest to us is the Si(111)-({radical}3x{radical}3)R30{degree}–Ag (Ag-Si-{radical}3 hereafter). In this thesis I systematically e plore effects of Ag deposition on the Ag-Si-{radical}3 at different temperatures, film thicknesses and deposition fluxes. The generated insight of the Ag system on the Si(111) is then applied to generate novel methods o… more
Date: April 4, 2012
Creator: Belianinov, Aleksey
open access

The analysis and minimization of oxygen contamination in the powder processing of molybdenum disilicide

Description: Problems with MoSi{sub 2} include low-temperature fracture toughness, high-temperature creep resistance, and ``pest`` phenomena. Oxygen introduced by powder processing may be the cause of some of these problems. This study led to the following conclusions: Supplied powders have significant oxygen present prior to processing (up to 2.5 %), in the form of silica on the surface. This oxygen contamination did not increase by exposure to air at room temperature. An improved powder processing method … more
Date: April 24, 1994
Creator: Shannon, K.
open access

ANALYSIS OF THE PERFORMANCE AND COST EFFECTIVENESS OF NINE SMALL WIND ENERGY CONVERSION SYSTEMS FUNDED BY THE DOE SMALL GRANTS PROGRAM

Description: This report presents an analysis of the technical performance and cost effectiveness of nine small wind energy conversion systems (SWECS) funded during FY 1979 by the U.S. Department of Energy. Chapter 1 gives an analytic framework with which to evaluate the systems. Chapter 2 consists of a review of each of the nine projects, including project technical overviews, estimates of energy savings, and results of economic analysis. Chapter 3 summarizes technical, economic, and institutional barriers… more
Date: April 1, 1982
Creator: Kay, J.
open access

Application of Monte Carlo criticality calculations to the Ames Laboratory Research Reactor

Description: >Thesis. The modeling of the Ames Laboratory Research Reactor core region and the input required to utilize the Monte Carlo computer code KENO for criticality calculations are described. Reactivity calculations in terms of k- effective were made for various reactor configurations and compared to measurements made on the actual reactor. (16 references) (auth)
Date: April 1, 1974
Creator: Hull, D.L.
open access

The application of psoralens to the study of DNA structure, function and dynamics

Description: A series of six nitroxide spin-labeled psoralens were designed, synthesized and tested as probes for DNA dynamics. The synthesis of these spin-labeled psoralen derivatives and their photoreactivity with double-stranded DNA fragments is described. The spin labels (nitroxides) were demonstrated to survive the uv irradiation required to bind the probe to the target DNA. EPR spectra of the photobound spin-labels indicate that they do not wobble with respect to the DNA on the time-scales investigate… more
Date: April 1, 1991
Creator: Spielmann, P. H.
open access

Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report

Description: Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, ind… more
Date: April 30, 1990
Creator: Chafetz, H. S.
open access

Baryon stopping and hadronic spectra in Pb-Pb collisions at 158 GeV/nucleon

Description: Baryon stopping and particle production in Pb+Pb collisions at 158 GeV/nucleon are studied as a function of the collision centrality using new proton, antiproton, charged kaon and charged pion production data measured with the NA49 experiment at the CERN Super Proton Synchrotron (SPS). Stopping, which is measured by the shift in rapidity of net protons or baryons from the initial beam rapidity, increases in more central collisions. This is expected from a geometrical picture of the collisions. … more
Date: April 12, 2000
Creator: Cooper, Glenn E.
open access

Behavior of the Diamond Difference and Low-Order Nodal Numerical Transport Methods in the Thick Diffusion Limit for Slab Geometry

Description: The objective of this work is to investigate the thick diffusion limit of various spatial discretizations of the one-dimensional, steady-state, monoenergetic, discrete ordinates neutron transport equation. This work specifically addresses the two lowest order nodal methods, AHOT-N0 and AHOT-N1, as well as reconsiders the asymptotic limit of the Diamond Difference method. The asymptotic analyses of the AHOT-N0 and AHOT-N1 nodal methods show that AHOT-N0 does not possess the thick diffusion limit… more
Date: April 17, 2007
Creator: Gill, D. F.
open access

Behavior of the particle transport coefficients near the density limit in MTX

Description: The perturbed particle transport coefficients were determined for a range of plasma conditions in the Alcator C tokamak, a component of the Microwave Tokamak Experiment (MTX), from analysis of density perturbations created in gas modulation experiments. Density measurements from a 15 chord far-infrared interferometer were sufficiently detailed to allow radial profiles of the transport coefficients to be resolved. Gas modulation experiments were carried out on plasmas over a range of relatively … more
Date: April 1, 1993
Creator: Marinak, M. M.
open access

A calorimetric measurement of the strong coupling constant in electron-positron annihilation at a center-of-mass energy of 91.6 GeV

Description: In this work, a measurement of the strong coupling constant {alpha}{sub s} in e{sup +}e{sup {minus}} annihilation at a center-of-mass energy of 91.6 GeV is presented. The measurement was performed with the SLD at the Stanford Linear Collider facility located at the Stanford Linear Accelerator Center in California. The procedure used consisted of measuring the rate of hard gluon radiation from the primary quarks in a sample of 9,878 hadronic events. After defining the asymptotic manifestation of… more
Date: April 1, 1994
Creator: Martirena, S. G.
open access

Cellulose and cellobiose: adventures of a wandering organic chemist in theoretical chemistry

Description: The energies arising from the rotation of free hydroxyl groups in the central glucose residue of a cellulose crystalline assembly, calculated using RHF, DFT, and FMO2/MP2 methods, will be presented. In addition, interactions of this central glucose residue with some of the surrounding residues (selected on the basis of the interaction strengths) are analyzed. The mechanism of acid-catalyzed hydrolysis of cellobiose, which is the repeating unit of cellulose. Energies corresponding to the differe… more
Date: April 3, 2012
Creator: Baluyut, John
open access

Character and Effective Leadership of the Knowledge Worker

Description: Ulrich in the forward to the Zenger and Folkman (2002) book, ''The Extraordinary Leader'', wrote about the importance of character in leadership stating, ''Everything about great leaders radiates from character. Character improves the probability of exhibiting strong interpersonal skill. Some of this perceived character is innate . . . but more is driven by the leader's self-awareness and interactions with others'' (p. ix). The purpose of this study was to explore the relationship between leade… more
Date: April 20, 2005
Creator: Khoury, A E
open access

Charged particle spectra in {sup 32}S + {sup 32}S interactions at 200 GeV/nucleon from CCD-imaged nuclear collisions in a streamer chamber

Description: We have measured the transverse momentum spectra 1/p{sub T} dN/dp{sub T} and rapidity distributions dN/dy of negatively charged hadrons and protons for central {sup 32}S + {sup 32}S interactions at 200 GeV/nucleon incident energy. The negative hadron dN/dy distribution is too broad to be accounted for by thermal models which demand isotropic particle emission. It is compatible with models which emphasize longitudinal dynamics, by either a particle production mechanism, as in the Lund fragmentat… more
Date: April 1, 1992
Creator: Teitelbaum, L. P.
open access

Chemical dynamics in time and energy space

Description: The development of a versatile picosecond ultraviolet/vacuum ultraviolet temporal spectrometer and its potential use for measuring internal energy redistribution in isolated molecules are described in detail. A detailed description of the double-pass Nd:YAG amplifier and the dye amplifiers is given with the pulse energies achieved in the visible, ultraviolet, and vacuum ultraviolet. The amplified visible pulses are shown to be of sub-picosecond duration and near transform limited. The instrumen… more
Date: April 1, 1993
Creator: Myers, J. D.
open access

Chemistry of coal model compounds: cleavage of aliphatic bridges between aromatic nuclei catalyzed by Lewis acids.

Description: The condensed polynuclear aromatic clusters of coal are believed to be linked principally by straight-chain aliphatic bridges varying from 0 to 4 carbon atoms in length and the cleavage of these linkages is expected to be an important step in the coal liquefaction process. This study focuses on the means by which Lewis acid catalysts, specifically AlCl/sub 3/ and ZnCl/sub 2/, promote the cleavage of these linkages. To facilitate product identification and interpretation of reaction mechanisms, … more
Date: April 1, 1978
Creator: Taylor, N. D.
open access

A Comparison of "Total Dust" and Inhalable Personal Sampling for Beryllium Exposure.

Description: In 2009, the American Conference of Governmental Industrial Hygienists (ACGIH) reduced the Beryllium (Be) 8-hr Time Weighted Average Threshold Limit Value (TLV-TWA) from 2.0 {micro}g/m{sup 3} to 0.05 {micro}g/m{sup 3} with an inhalable 'I' designation in accordance with ACGIH's particle size-selective criterion for inhalable mass. Currently, per the Department of Energy (DOE) requirements, the Lawrence Livermore National Laboratory (LLNL) is following the Occupational Health and Safety Administ… more
Date: April 25, 2012
Creator: Carter, C. M.
open access

Conformal field theory on affine Lie groups

Description: Working directly on affine Lie groups, we construct several new formulations of the WZW model, the gauged WZW model, and the generic affine-Virasoro action. In one formulation each of these conformal field theories (CFTs) is expressed as a one-dimensional mechanical system whose variables are coordinates on the affine Lie group. When written in terms of the affine group element, this formulation exhibits a two-dimensional WZW term. In another formulation each CFT is written as a two-dimensional… more
Date: April 1, 1996
Creator: Clubok, K.S.
open access

CP violating anomalous top-quark coupling in p$\bar{p}$ collision at $\sqrt{s}=1.96$ TeV

Description: We conduct the first study of the T-odd correlations in tt events produced in p{bar p} collision at the Fermilab Tevatron collider that can be used to search for CP violation. We select events which have lepton+jets final states to identify t{bar t} events and measure counting asymmetries of several physics observables. Based on the result, we search the top quark anomalous couplings at the production vertex at the Tevatron. In addition, Geant4 development, photon identification, the discrimina… more
Date: April 1, 2011
Creator: Lee, Sehwook & U., /Iowa State
open access

Cross section measurements for quasi-elastic neutrino-nucleus scattering with the MINOS near detector

Description: The Main Injector Neutrino Oscillation Search (MINOS) is a long baseline neutrino oscillation experiment based at the Fermi National Accelerator Laboratory (FNAL) in Chicago, Illinois. MINOS measures neutrino interactions in two large iron-scintillator tracking/sampling calorimeters; the Near Detector on-site at FNAL and the Far Detector located in the Soudan mine in northern Minnesota. The Near Detector has recorded a large number of neutrino interactions and this high statistics dataset can b… more
Date: April 1, 2008
Creator: Dorman, Mark Edward & London, /University Coll.
open access

Crossed molecular beam studies of atmospheric chemical reaction dynamics

Description: The dynamics of several elementary chemical reactions that are important in atmospheric chemistry are investigated. The reactive scattering of ground state chlorine or bromine atoms with ozone molecules and ground state chlorine atoms with nitrogen dioxide molecules is studied using a crossed molecular beams apparatus with a rotatable mass spectrometer detector. The Cl + O{sub 3} {yields} ClO + O{sub 2} reaction has been studied at four collision energies ranging from 6 kcal/mole to 32 kcal/mol… more
Date: April 1, 1993
Creator: Zhang, Jingsong
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