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in subjects: "Surfaces"

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08-ERD-071 Final Report: New Molecular Probes and Catalysts for Bioenergy Research

A major thrust in bioenergy research is to develop innovative methods for deconstructing plant cell wall polymers, such as cellulose and lignin, into simple monomers that can be biologically converted to ethanol and other fuels. Current techniques for monitoring a broad array of cell wall materials and specific degradation products are expensive and time consuming. To monitor various polymers and assay their breakdown products, molecular probes for detecting specific carbohydrates and lignins a… more

Date: March 7, 2011

Creator: Thelen, M. P.; Rowe, A. A.; Siebers, A. K. & Jiao, Y.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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10 NSEC Resolution Counter for Multiparticle Atom Probe Time-of-Flight Measurements.

No Description Available.

Date: January 1, 1972

Creator: Berger, A. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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100-keV Faraday cup design: materials and structure

A Faraday cup design for a 1 mA.cm/sup -2/ 100-keV, light-ion-beam measurement in background plasma is proposed. Features of this shielded, three-grid structure with deep target are described, and a mechanical draft is included. In the appendix, we reference and survey results of experiments reporting the number and energy range of secondary electrons and back-scattered ions originating on various metal surfaces bombarded with approximately 100-keV hydrogen and deuterium ions. Choice of target … more

Date: October 11, 1976

Creator: Jones, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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234-5 status reports

On July 14, 1949, and office memorandum was written about operations of a reprocessing building on the Hanford Site being suspended due to the mishandling of some plutonium powder. The letter describes the process of decontamination of the building surfaces, and the ventilation of the rooms of that building. It also describes the problem with the ventilation fans due to increased temperature and pressures.

Date: July 14, 1949

Creator: Lowe, W. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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[12th International workshop on Inelastic Ion-Surface Collisions]

The twelfth international workshop on inelastic ion surface collisions was held at the Bahia Mar Resort and Conference Center on South Padre Island, Texas (USA) from January 24-29, 1999. The workshop brought together most of the leading researchers from around the world to focus on both the theoretical and experimental aspects of particle - surface interactions and related topics.

Date: October 15, 1999

Creator: Rabalais, J. W. & Nordlander, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

14th international symposium on molecular beams

This report discusses research being conducted with molecular beams. The general topic areas are as follows: Clusters I; reaction dynamics; atomic and molecular spectroscopy; clusters II; new techniques; photodissociation & dynamics; and surfaces.

Date: September 1, 1992

Item Type: Article

Partner: UNT Libraries Government Documents Department

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14th International Symposium on Molecular Beams

Date: 1992-22~

Item Type: Article

Partner: UNT Libraries Government Documents Department

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1974 annual summary report

No Description Available.

Date: July 1, 1975

Item Type: Report

Partner: UNT Libraries Government Documents Department

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1st-Principles Step- and Kink-Formation Energies on Cu(111)

In rough agreement with experimental values derived from Cu island shapes vs. temperature, ab-initio calculations yield formation energies of 0.27 and 0.26 eV/ step-edge-atom for (100)- and (111)-micro facet steps on Cu(lll), and 0.09 and 0.12 eV per kink in those steps. Comparison to ab-initio results for Al and Pt shows that as a rule, the average formation energy of straight steps on a close-packed metal surface equals -7% of the metal's cohesive energy.

Date: May 26, 1999

Creator: Feibelman, Peter J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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2005 Chemical Reactions at Surfaces

The Gordon Research Conference (GRC) on 2005 Chemical Reactions at Surfaces was held at Ventura Beach Marriott, Ventura California from February 13, 2005 through February 18, 2005. The Conference was well-attended with 124 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the form… more

Date: March 14, 2006

Creator: Friend, Cynthia M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ab initio calculation of ground- and excited-state properties of surfaces. [Ge(111):As and Si(111):As]

A new approach for surface studies using the density functional formalism for structural determination and a first principles many-body theory for the quasiparticle surface state energies is discussed. The many-body calculation involves the evaluation of the electron self-energy operator including both local fields and dynamical screening effects. Results for the Ge(111):As and Si(111):As surface are in excellent agreement with recent angle-resolved photoemission data and show a substantially l… more

Date: April 1, 1987

Creator: Louie, S.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ab-initio calculations of the hydrogen-uranium system. Part I: Surface phenomena, absorption, transport and trapping

Density functional theory was applied to the initial steps of uranium hydriding: surface phenomena, absorption, bulk transport and trapping. H adsorbs exothermically to the (0 0 1) surface, yet H absorption into the bulk is endothermic, with off-center octahedral absorption having the lowest absorption energy of 0.39 eV, relative to molecular H{sub 2}. H absorption in interstitial sites causes a local softening of the bulk modulus. Diffusion of H in unstrained {alpha}-U has a barrier of 0.6 eV.… more

Date: January 1, 2009

Creator: Taylor, Christopher D & Lillard, R Scott

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ab initio study of the epitaxial growth of Ge on Si(100) surface

We identify the binding sites for adsorption of a single Ge atom on the Si(100) surface using ab initio total energy calculations. The calculated diffusion barriers are in excellent agreement with experimental estimates. Using a large supercell we resolve the controversy regarding the binding geometry and migration path for the adatom, and investigate the influence of the adatom on the buckling of Si dimers. The adatom induces a buckling defect that is frequently observed using scanning tunneli… more

Date: November 1, 1993

Creator: Milman, V.; Pennycook, S. J.; Jesson, D. E.; Payne, M. C. & Stich, I.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ablation of material by front surface spallation

Laser irradiation can be utilized to remove (i.e., ablate) material in a controlled manner by a hydrodynamic process, referred to as front surface spallation. In this process, a thin layer next to a free surface is heated to a level (below vaporization) so rapidly that it cannot undergo thermal expansion during laser heating. This generates a stress pulse, which propagates both inward and toward the free surface, with an initial amplitude that can be calculated using the Grueneisen coefficient.… more

Date: January 1, 1991

Creator: Dingus, R. S. & Scammon, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ABRASIVE BLASTING FOR CLEANING PARTS. (Experiment Performed August 18 through August 25, 1945

No Description Available.

Date: September 1, 1945

Creator: McWherter, J.R. & Yerazunis, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Abrasive wear by diesel engine coal-fuel and related particles

The purpose of the work summarized in this report was to obtain a basic understanding of the factors which are responsible for wear of the piston ring and cylinder wall surfaces in diesel engines utilizing coal-fuel. The approach included analytical studies using scanning electron microscopy and energy dispersive x-ray analyses to characterize coal-fuel and various combustion particles, and two different wear tests. The wear tests were a modified pin-on-disk test and a block-on-ring test capabl… more

Date: September 1, 1994

Creator: Ives, L. K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Absolute dissipative drift-wave instabilities in tokamaks

Contrary to previous theoretical predictions, it is shown that the dissipative drift-wave instabilities are absolute in tokamak plasmas. The existence of unstable eigenmodes is shown to be associated with a new eigenmode branch induced by the finite toroidal couplings.

Date: July 1, 1979

Creator: Chen, L.; Chance, M. S. & Cheng, C. Z.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Acceleration using total internal reflection

This report considers the use of a dielectric slab undergoing total internal reflection as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of the dielectric for polarized incident waves. We present an experimental arrangement for testing the performance of the method, using apparatus under construction for the Grating Acceleration experiment at Brookhaven National Laboratory. 13 refs., 4 figs., 2 tabs.

Date: June 7, 1991

Creator: Fernow, R.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Accumulated surface damage on ZnS crystals produced by closely spaced pairs of picosecond laser pulses

Excitation of a transparent ZnS crystal by repetitive picosecond dye laser pulses causes an accumulated surface modification leading to optical damage. The onset of the damage is detected by an abrupt increase in the emission of neutral Zn (and possibly S/sub 2/) from the surface. Comparison of the neutral emission thresholds with pulse-pair and single-pulse excitation shows that linear absorption is the dominant laser-surface interaction. In general, this measurement technique shows considerab… more

Date: December 1, 1988

Creator: Chase, L. L. & Lee, H. W. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Accurate Micrometer for Corrosion Samples

A micrometer that utilizes eddy current techniques is described. The gage is capable of measuring nominal 0.5000-in. aluminum rods to an accuracy of plus or minus 0.00005 in., and is unaffected by residual nonconductive surface filins such as oxides or corrosion products. (auth)

Date: June 1, 1960

Creator: Woodward, W. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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ACME Algorithms for Contact in a Multiphysics Environment API Version 0.3a

An effort is underway at Sandia National Laboratories to develop a library of algorithms to search for potential interactions between surfaces represented by analytic and discretized topological entities. This effort is also developing algorithms to determine forces due to these interactions for transient dynamics applications. This document describes the Application Programming Interface (API) for the ACME (Algorithms for Contact in a Multiphysics Environment) library.

Date: April 1, 2001

Creator: BROWN, KEVIN H.; GLASS, MICHEAL W.; GULLERUD, ARNE S.; HEINSTEIN, MARTIN W.; JONES, REESE E. & SUMMERS, RANDALL M.

Item Type: Report

Partner: UNT Libraries Government Documents Department