Resource Type

Language

Small power plant reverse trade mission (open access)

Small power plant reverse trade mission

This draft report was prepared as required by Task No. 2 of the US Department of Energy, Grant No. FG07-89ID12850 Reverse Trade Mission to Acquaint International Representatives with US Power Plant and Drilling Technology'' (mission). As described in the grant proposal, this report covers the reactions of attendees toward US technology, its possible use in their countries, and an evaluation of the mission by the staff leaders. Note this is the draft report of one of two missions carried out under the same contract number. Because of the diversity of the mission subjects and the different attendees at each, a separate report for each mission has been prepared. This draft report has been sent to all mission attendees, specific persons in the US Department of Energy and Los Alamos National Lab., the California Energy Commission (CEC), and various other governmental agencies.
Date: September 6, 1989
Creator: unknown
System: The UNT Digital Library
An Update on the Status of the NIF Power Conditioning System (open access)

An Update on the Status of the NIF Power Conditioning System

The National Ignition Facility (NIF) Power Conditioning System provides the pulsed excitation required to drive flashlamps in the laser's optical amplifiers. Modular in design, each of the 192 Main Energy Storage Modules (MESMs) stores up to 2.2 MJ of electrical energy in its capacitor bank before delivering the energy to 20 pairs of flashlamps in a 400 {micro}s pulse (10% power points). The peak current of each MESM discharge is 0.5 MA. Production, installation, commissioning and operation of the NIF Power Conditioning continue to progress rapidly, with the goals of completing accelerated production and commissioning by early 2008, while maintaining an aggressive operation schedule. To date, more than 97% of the required modules have been assembled, shipped and installed in the facility, representing more that 380 MJ of stored energy available for driving NIF flashlamps. The MESMs have displayed outstanding reliability during daily, multiple-shift operations.
Date: September 6, 2007
Creator: Arnold, P. A.; Hulsey, S.; Ullery, G. T.; Petersen, D. E.; Pendleton, D. L.; Ollis, C. W. et al.
System: The UNT Digital Library
More visible effects of the hidden sector (open access)

More visible effects of the hidden sector

There is a growing appreciation that hidden sector dynamics may affect the supersymmetry breaking parameters in the visible sector (supersymmetric standard model), especially when the dynamics is strong and superconformal. We point out that there are effects that have not been previously discussed in the literature. For example, the gaugino masses are suppressed relative to the gravitino mass. We discuss their implications in the context of various mediation mechanisms. The issues discussed include anomaly mediation with singlets, the mu (B mu) problem in gauge and gaugino mediation, and distinct mass spectra for the superparticles that have not been previously considered.
Date: September 6, 2007
Creator: Murayama, Hitoshi; Murayama, Hitoshi; Nomura, Yasunori & Poland, David
System: The UNT Digital Library
Atomistically-informed Dislocation Dynamics in fcc Crystals (open access)

Atomistically-informed Dislocation Dynamics in fcc Crystals

We develop a nodal dislocation dynamics (DD) model to simulate plastic processes in fcc crystals. The model explicitly accounts for all slip systems and Burgers vectors observed in fcc systems, including stacking faults and partial dislocations. We derive simple conservation rules that describe all partial dislocation interactions rigorously and allow us to model and quantify cross-slip processes, the structure and strength of dislocation junctions and the formation of fcc-specific structures such as stacking fault tetrahedra. The DD framework is built upon isotropic non-singular linear elasticity, and supports itself on information transmitted from the atomistic scale. In this fashion, connection between the meso and micro scales is attained self-consistently with core parameters fitted to atomistic data. We perform a series of targeted simulations to demonstrate the capabilities of the model, including dislocation reactions and dissociations and dislocation junction strength. Additionally we map the four-dimensional stress space relevant for cross-slip and relate our findings to the plastic behavior of monocrystalline fcc metals.
Date: September 6, 2006
Creator: Martinez, E.; Marian, J.; Arsenlis, T.; Victoria, M. & Perlado, J. M.
System: The UNT Digital Library
Recovery of Minerals and Metals from Geothermal Fluids (open access)

Recovery of Minerals and Metals from Geothermal Fluids

None
Date: September 6, 2005
Creator: Bourcier, W L; Lin, M & Nix, G
System: The UNT Digital Library
An atomic force microcopy study of the mechanical and electricalproperties of monolayer films of molecules with aromatic end groups (open access)

An atomic force microcopy study of the mechanical and electricalproperties of monolayer films of molecules with aromatic end groups

The effect of intermolecular {pi}-{pi} stacking on the electrical and mechanical properties of monolayer films molecules containing aromatic groups was studied using atomic force microscopy. Two types of aromatic molecules, (4-mercaptophenyl) anthrylacetylene (MPAA) and (4-mercaptophenyl)-phenylacetylene (MPPA) were used as model systems with different {pi}-{pi} stacking strength. Monolayer films of these molecules on Au(111) surfaces exhibited conductivities differing by more than one order of magnitude, MPAA being the most conductive and MPPA the least conductive. The response to compressive loads by the AFM tip was also found to be very different for both molecules. In MPAA films distinct molecular conductivity changes are observed upon mechanical perturbation. This effect however was not observed on the MPPA film, where intermolecular {pi}-{pi} interactions are likely weaker.
Date: September 6, 2007
Creator: Fang, Liang; Park, J.Y.; Ma, H.; Jen, A.K.-Y. & Salmeron, M.
System: The UNT Digital Library
Interaction of Nocturnal Low-Level Jets with Urban Geometries as seen in Joint URBAN 2003 Data (open access)

Interaction of Nocturnal Low-Level Jets with Urban Geometries as seen in Joint URBAN 2003 Data

As accurate modeling of atmospheric flows in urban environments requires sophisticated representation of complex urban geometries, much work has been devoted to treatment of the urban surface. However, the importance of the larger-scale flow impinging upon the urban complex to the flow, transport and dispersion within it and downwind has received less attention. Building-resolving computational fluid dynamics (CFD) models are commonly employed to investigate interactions between the flow and three-dimensional structures comprising the urban environment, however such models are typically forced with simplified boundary conditions that fail to include important regional-scale phenomena that can strongly influence the flow within the urban complex and downwind. This paper investigates the interaction of an important and frequently occurring regional-scale phenomenon, the nocturnal low-level jet (LLJ), with urban-scale turbulence and dispersion in Oklahoma City using data from the Joint URBAN 2003 (JU2003) field experiment. Two simulations of nocturnal tracer release experiments from JU2003 using Lawrence Livermore National laboratory's FEM3MP CFD model yield differing levels of agreement with the observations in wind speed, turbulence kinetic energy (TKE) and concentration profiles in the urban wake, approximately 750m downwind of the central business district. Profiles of several observed turbulence parameters at this location indicate characteristics of both …
Date: September 6, 2006
Creator: Lundquist, J. K. & Mirocha, J. D.
System: The UNT Digital Library
Geometric metastability, quivers and holography (open access)

Geometric metastability, quivers and holography

We use large N duality to study brane/anti-brane configurations on a class of Calabi-Yau manifolds. With only branes present, the Calabi-Yau manifolds in question give rise to N=2 ADE quiver theories deformed by superpotential terms. We show that the large N duality conjecture of hep-th/0610249 reproduces correctly the known qualitative features of the brane/anti-brane physics. In the supersymmetric case, the gauge theories have Seiberg dualities which are represented as flops in the geometry. Moreover, the holographic dual geometry encodes the whole RG flow of the gauge theory. In the non-supersymmetric case, the large N duality predicts that the brane/anti-brane theories also enjoy such dualities, and allows one to pick out the good description at a given energy scale.
Date: September 6, 2007
Creator: Aganagic, Mina; Aganagic, Mina; Beem, Christopher & Freivogel, Ben
System: The UNT Digital Library
Optical switching and contrast enhancement in intense laser systems by cascaded optical parametric amplification (open access)

Optical switching and contrast enhancement in intense laser systems by cascaded optical parametric amplification

Optical parametric chirped-pulse amplification (OPCPA) can be used to improve the prepulse contrast in chirped-pulse amplification systems by amplifying the main pulse with a total saturated OPCPA gain, while not affecting the preceding prepulses of the seed oscillator mode-locked pulse train. We show that a simple modification of a multistage OPCPA system into a cascaded optical parametric amplifier (COPA) results in an optical switch and extreme contrast enhancement which can completely eliminate the preceding and trailing oscillator pulses. Instrument-limited measurement of prepulse contrast ratio of 1.4 x 10{sup 11} is demonstrated from COPA at a 30-mJ level.
Date: September 6, 2005
Creator: Jovanovic, I; Haefner, C; Wattellier, B & Barty, C J
System: The UNT Digital Library
Exploring Lifetime Effects in Femtoscopy (open access)

Exploring Lifetime Effects in Femtoscopy

We investigate the role of lifetime effects from resonances and emission duration tails in femtoscopy at RHIC in two Blast-Wave models. We find the non-Gaussian components compare well with published source imaged data, but the value of R{sub out} obtained from Gaussian fits is not insensitive to the non-Gaussian contributions when realistic acceptance cuts are applied to models.
Date: September 6, 2005
Creator: Brown, D.; Soltz, R.; Newby, J. & Kisiel, A.
System: The UNT Digital Library
Alignment validation (open access)

Alignment validation

The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.
Date: September 6, 2008
Creator: ALICE; ATLAS; CMS; LHCb & Golling, Tobias
System: The UNT Digital Library
Material dynamics under extreme conditions of pressure and strain rate (open access)

Material dynamics under extreme conditions of pressure and strain rate

Solid state experiments at extreme pressures (10-100 GPa) and strain rates ({approx}10{sup 6}-10{sup 8}s{sup -1}) are being developed on high-energy laser facilities, and offer the possibility for exploring new regimes of materials science. These extreme solid-state conditions can be accessed with either shock loading or with a quasi-isentropic ramped pressure drive. Velocity interferometer measurements establish the high pressure conditions. Constitutive models for solid-state strength under these conditions are tested by comparing 2D continuum simulations with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples. Lattice compression, phase, and temperature are deduced from extended x-ray absorption fine structure (EXAFS) measurements, from which the shock-induced {alpha}-{omega} phase transition in Ti and the {alpha}-{var_epsilon} phase transition in Fe are inferred to occur on sub-nanosec time scales. Time resolved lattice response and phase can also be measured with dynamic x-ray diffraction measurements, where the elastic-plastic (1D-3D) lattice relaxation in shocked Cu is shown to occur promptly (< 1 ns). Subsequent large-scale molecular dynamics (MD) simulations elucidate the microscopic dynamics that underlie the 3D lattice relaxation. Deformation mechanisms are identified by examining the residual microstructure in recovered samples. The slip-twinning threshold in single-crystal Cu shocked along the [001] direction is shown to …
Date: September 6, 2005
Creator: Remington, Bruce A.; Allen, Patrick; Bringa, Eduaro; Hawreliak, Jim; Ho, Darwin; Lorenz, K. Thomas et al.
System: The UNT Digital Library
Ablation gas dynamics of low-Z materials illuminated by soft x-rays (open access)

Ablation gas dynamics of low-Z materials illuminated by soft x-rays

Though many of our results will have much greater generality, the main purpose of this paper is to provide a simple, accurate, physical theory of what happens when a Planckian spectrum of soft x-rays is incident on one side of the slab of initially cold, dense material, of small nuclear charge Z. Our approach will be to consider in some detail the idealized situation. A semi-infinite (x {le} 0) slab of initially cold (T < 300 K), dense ({rho} {approximately} 1 {minus} 10 g/cc), low-Z (Z < 5) material is suddenly subjected at time t = 0 and thereafter to radiation incoming from x = +{infinity} with a specific intensity in directions toward the slab that is Planckian, characterized by a black-body temperature, T{sub R} in the soft x-ray region.
Date: September 6, 1991
Creator: Hatchett, S.P.
System: The UNT Digital Library
A high resolution capacitive imaging sensor for manufacturing applications (open access)

A high resolution capacitive imaging sensor for manufacturing applications

A high resolution capacitive image sensing technique for measuring edge and surface profiles during manufacturing processes has been invented. A prototype device utilizing this technique consists of two 0.020 in. (500 {mu}m) diameter electrodes fabricated on a printed circuit board with a 0.010 in. (250 {mu}m) gap between them. As the device is mechanically scanned over the workpiece, the spatial variations in the edge or surface to be measured interfere with an electric field imposed between the electrodes, altering the mutual capacitance. The sensor functions as a near field proximity sensor producing range images of surface imperfections. This sensor has been used in applications requiring a preview image of burrs on the edge of a machined part and other processes requiring an inspection image after automated deburring operations. 10 refs., 8 figs.
Date: September 6, 1990
Creator: Novak, J. L. & Wiczer, J. J.
System: The UNT Digital Library
Design of Long Induction Linacs (open access)

Design of Long Induction Linacs

A self-consistent design strategy for induction linacs is presented which addresses the issues of brightness preservation against space charge induced emittance growth, minimization of the beam breakup instability and the suppression of beam centroid motion due to chromatic effects (corkscrew) and misaligned focusing elements. A simple steering algorithm is described that widens the effective energy bandwidth of the transport system.
Date: September 6, 1990
Creator: Caporaso, G.J. & Cole, A.G.
System: The UNT Digital Library
Inertial Fusion and High-Energy-Density Science in the United States (open access)

Inertial Fusion and High-Energy-Density Science in the United States

Inertial fusion and high-energy density science worldwide is poised to take a great leap forward. In the US, programs at the University of Rochester, Sandia National Laboratories, Los Alamos National Laboratory, Lawrence Livermore National Laboratory (LLNL), the Naval Research Laboratory, and many smaller laboratories have laid the groundwork for building a facility in which fusion ignition can be studied in the laboratory for the first time. The National Ignition Facility (NIF) is being built by the Department of Energy's National Nuclear Security Agency to provide an experimental test bed for the US Stockpile Stewardship Program (SSP) to ensure the dependability of the country's nuclear deterrent without underground nuclear testing. NIF and other large laser systems being planned such as the Laser MegaJoule (LMJ) in France will also make important contributions to basic science, the development of inertial fusion energy, and other scientific and technological endeavors. NIF will be able to produce extreme temperatures and pressures in matter. This will allow simulating astrophysical phenomena (on a tiny scale) and measuring the equation of state of material under conditions that exist in planetary cores.
Date: September 6, 2001
Creator: Tarter, C B
System: The UNT Digital Library
Simultaneous reactions at disk and porous electrodes (open access)

Simultaneous reactions at disk and porous electrodes

Advances in electrochemical engineering are reviewed and the methodology of analysis of electrochemical systems outlined. Examples illustrative of current research concern simultaneous reactions for flow-through porous electrodes and the more fundamental system of a rotating-disk electrode. Here the undesirable side reaction is the formation of dissolved hydrogen, and the main reaction is the deposition of copper from sulfuric acid solutions. Distributions of reaction rate, concentration, and potential describe the detailed system behavior. The side reaction is responsible for the poorly defined limiting-current plateau on the disk electrode and provides a limit for the maximum flow rate at which good recovery can be achieved with the porous electrode. 16 figures.
Date: September 6, 1976
Creator: Newman, J.
System: The UNT Digital Library
Construction and Operational Experience with a Superconducting Octupole Used to Trap Antihydrogen (open access)

Construction and Operational Experience with a Superconducting Octupole Used to Trap Antihydrogen

A superconducting octupole magnet has seen extensive service as part of the ALPHA experiment at CERN. ALPHA has trapped antihydrogen, a crucial step towards performing precision measurements of anti-atoms. The octupole was made at the Direct Wind facility by the Superconducting Magnet Division at Brookhaven National Laboratory. The magnet was wound with a six-around-one NbTi cable about 1 mm in diameter. It is about 300 mm long, with a radius of 25 mm and a peak field at the conductor of 4.04 T. Specific features of the magnet, including a minimal amount of material in the coil and coil ends with low multipole content, were advantageous to its use in ALPHA. The magnet was operated for six months a year for five years. During this time it underwent about 900 thermal cycles (between 4K and 100K). A novel operational feature is that during the course of data-taking the magnet was repeatedly shut off from its 950 A operating current. The magnet quenches during the shutoff, with a decay constant of 9 ms. Over the course of the five years, the magnet was deliberately quenched many thousands of times. It still performs well.
Date: September 6, 2011
Creator: Wanderer, P.; Escallier, J.; Marone, A. & Parker, B.
System: The UNT Digital Library
Zero and One Jet Combined NLO Analysis of the Top Quark Forward-backward Asymmetry (open access)

Zero and One Jet Combined NLO Analysis of the Top Quark Forward-backward Asymmetry

None
Date: September 6, 2013
Creator: Hoeche, Stefan; Huang, Junwu; Luisoni, Gionata; Schoenherr, Marek & Winter, Jan
System: The UNT Digital Library
Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources (open access)

Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources

Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original …
Date: September 6, 2012
Creator: Chao, Alex; Ratner, Daniel & Jiao, Yi
System: The UNT Digital Library
Enhanced and multiplexed detection via a novel RCA-aptamer based sensing system (open access)

Enhanced and multiplexed detection via a novel RCA-aptamer based sensing system

None
Date: September 6, 2006
Creator: Fischer, N O; Dolan, C E; Tarasow, T M & Tok, J H
System: The UNT Digital Library
A Conceptual model of coupled biogeochemical and hydrogeologicalprocesses affected by in situ Cr(VI) bioreduction in groundwater atHanford 100H Site (open access)

A Conceptual model of coupled biogeochemical and hydrogeologicalprocesses affected by in situ Cr(VI) bioreduction in groundwater atHanford 100H Site

The overall objective of this presentation is to demonstratea conceptual multiscale, multidomain model of coupling of biogeochemicaland hydrogeological processes during bioremediation of Cr(VI)contaminated groundwater at Hanford 100H site. A slow releasepolylactate, Hydrogen Release Compound (HRCTM), was injected in Hanfordsediments to stimulate immobilization of Cr(VI). The HRC injectioninduced a 2-order-of-magnitude increase in biomass and the onset ofreducing biogeochemical conditions [e.g., redox potential decreased from+240 to -130 mV and dissolved oxygen (DO) was completely removed]. Athree-well system, comprised of an injection well and upgradient anddowngradient monitoring wells, was used for conducting the in situbiostimulation, one regional flow (no-pumping) tracer test, and fivepumping tests along with the Br-tracer injection. Field measurements wereconducted using a Br ion-selective electrode and a multiparameter flowcell to collect hourly data on temperature, pH, redox potential,electrical conductivity, and DO. Groundwater sampling was conducted bypumping through specially designed borehole water samplers.Cross-borehole radar tomography and seismic measurements were carried outto assess the site background lithological heterogeneity and themigration pathways of HRC byproducts through groundwater after the HRCinjection.
Date: September 6, 2006
Creator: Faybishenko, B.; Long, P. E.; Hazen, T. C.; Hubbard, S. S.; Williams, K. H.; Peterson, J. E. et al.
System: The UNT Digital Library
Dissolution of FB-Line Residues Containing Beryllium Metal (open access)

Dissolution of FB-Line Residues Containing Beryllium Metal

Scrap materials containing plutonium (Pu) metal were dissolved at the Savannah River Site (SRS) as part of a program to disposition nuclear materials during the deactivation of the FB-Line facility. Some of these items contained both Pu and beryllium (Be) metal as a composite material. The Pu and Be metals were physically separated to minimize the amount of Be associated with the Pu; however, a dissolution flowsheet was required to dissolve small amounts of Be combined with the Pu metal using a dissolving solution containing nitric acid (HNO{sub 3}) and potassium fluoride (KF). Since the dissolution of Pu metal in HNO{sub 3}/fluoride (F{sup -}) solutions was well understood, the primary focus of the flowsheet development was the dissolution of Be metal. Initially, small-scale experiments were used to measure the dissolution rate of Be metal foils using conditions effective for the dissolution of Pu metal. The experiments demonstrated that the dissolution rate was nearly independent of the HNO{sub 3} concentration over the limited range of investigation and only a moderate to weak function of the F{sup -} concentration. The effect of temperature was more pronounced, significantly increasing the dissolution rate between 40 and 105 C. The offgas analysis from three Be …
Date: September 6, 2005
Creator: RUDISILL, TRACY S. & CROWDER, MARK L.
System: The UNT Digital Library
Use of Plasmon Coupling to Reveal the Dynamics of DNA Bending and Cleavage by Single EcoRV Restriction Enzymes (open access)

Use of Plasmon Coupling to Reveal the Dynamics of DNA Bending and Cleavage by Single EcoRV Restriction Enzymes

Pairs of Au nanoparticles have recently been proposed asplasmon rulers based on the dependence of their light scattering on theinterparticle distance. Preliminary work has suggested that plasmonrulers can be used to measure and monitor dynamic distance changes overthe 1 to 100nm length scale in biology. Here, we substantiate thatplasmon rulers can be used to effectively measure dynamical biophysicalprocesses by applying the ruler to a system that has been investigatedextensively using ensemble kinetic measurements: the cleavage of DNA bythe restriction enzyme EcoRV. Temporal resolutions of up to 240 Hz wereobtained, and the end-to-end extension of up to 1000 individual dsDNAenzyme substrates could be monitored in parallel for hours. The singlemolecule cleavage trajectories acquired here agree well with valuesobtained in bulk through other methods, and confirm well-known featuresof the cleavage process, such as the fact that the DNA is bent prior tocleavage. New dynamical information is revealed as well, for instance,the degree of softening of the DNA just prior to cleavage. The unlimitedlife time, high temporal resolution, and high signal/noise make theplasmon ruler an excellent tool for studying macromolecular assembliesand conformational changes at the single molecule level.
Date: September 6, 2006
Creator: Reinhard, Bjorn; Sheikholeslami, Sassan; Mastroianni, Alexander; Alivisatos, A. Paul & Liphardt, Jan
System: The UNT Digital Library