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2,606 Matching Results
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Prototype Weigh-In-Motion Performance
Oak Ridge National Laboratory (ORNL) has developed and patented methods to weigh slowly moving vehicles. We have used this technology to produce a portable weigh-in-motion system that is robust and accurate. This report documents the performance of the second-generation portable weigh-in-motion prototype (WIM Gen II). The results of three modes of weight determination are compared in this report: WIM Gen II dynamic mode, WIM Gen II stop-and-go mode, and static (parked) mode on in-ground, static scales. The WIM dynamic mode measures axle weights as the vehicle passes over the system at speeds of 3 to 7 miles per hour (1.3 to 3.1 meters/second). The WIM stop-and-go mode measures the weight of each axle of the vehicle as the axles are successively positioned on a side-by-side pair of WIM measurement pads. In both measurement modes the center of balance (CB) and the total weight are obtained by a straight-forward calculation from axle weights and axle spacings. The performance metric is measurement error (in percent), which is defined as 100 x (sample standard deviation)/(average); see Appendix A for details. We have insufficient data to show that this metric is predictive. This report details the results of weight measurements performed in May 2005 …
Date:
October 1, 2006
Creator:
Abercrombie, Robert K; Beshears, David L; Hively, Lee M; Scudiere, Matthew B & Sheldon, Frederick T
Object Type:
Report
System:
The UNT Digital Library
Accelerating DSMC data extraction.
In many direct simulation Monte Carlo (DSMC) simulations, the majority of computation time is consumed after the flowfield reaches a steady state. This situation occurs when the desired output quantities are small compared to the background fluctuations. For example, gas flows in many microelectromechanical systems (MEMS) have mean speeds more than two orders of magnitude smaller than the thermal speeds of the molecules themselves. The current solution to this problem is to collect sufficient samples to achieve the desired resolution. This can be an arduous process because the error is inversely proportional to the square root of the number of samples so we must, for example, quadruple the samples to cut the error in half. This work is intended to improve this situation by employing more advanced techniques, from fields other than solely statistics, for determining the output quantities. Our strategy centers on exploiting information neglected by current techniques, which collect moments in each cell without regard to one another, values in neighboring cells, nor their evolution in time. Unlike many previous acceleration techniques that modify the method itself, the techniques examined in this work strictly post-process so they may be applied to any DSMC code without affecting its fidelity …
Date:
October 1, 2006
Creator:
Gallis, Michail A. & Piekos, Edward Stanley
Object Type:
Report
System:
The UNT Digital Library
Study of collisons of supersymmetric top Quark in the channel stop anti-stop -> e+- mu-+ sneutrino anti-sneutrino b anti-b with the experience of D0 at the Tevatron. Callibration of the electromagnetic calorimeter at D0.
Supersymmetry is one of the most natural extensions of the Standard Model. At low energy it may consist in the Minimal Supersymmetric Standard Model which is the framework chosen to perform the search of the stop with 350 pb{sup -1} of data collected by D0 during the RunIIa period of the TeVatron. They selected the events with an electron, a muon, missing transverse energy and non-isolated tracks, signature for the stop decay in 3-body ({bar t} {yields} bl{bar {nu}}). Since no significant excess of signal is seen, the results are interpreted in terms of limit on the stop production cross-sections, in such a way that they extend the existing exclusion region in the parameter space (m{sub {bar t}},m{sub {bar {nu}}}) up to stop masses of 168 (140) GeV for sneutrino masses of 50 (94) GeV. Finally because of the crucial role of the electromagnetic calorimeter, a fine calibration was performed using Z {yields} e{sup +}e{sup -} events, which improved significantly the energy resolution.
Date:
October 1, 2006
Creator:
Mendes, Aurelien & /Marseille U., Luminy
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Conservation assessment for the Siskiyou Mountains salamander and Scott Bar salamander in northern California.
The purpose of this conservation assessment is to summarize existing knowledge regarding the biology and ecology of the Siskiyou Mountains salamander and Scott Bar salamander, identify threats to the two species, and identify conservation considerations to aid federal management for persistence of the species. The conservation assessment will serve as the basis for a conservation strategy for the species.
Date:
October 20, 2006
Creator:
Vinikour, W. S.; LaGory, K. E.; Adduci, J. J. & Division, Environmental Science
Object Type:
Report
System:
The UNT Digital Library
Chemical Effects Head-Loss Research in Support of Generic Safety Issue 191.
This summary report describes studies conducted at Argonne National Laboratory on the potential for chemical effects on head loss across sump screens. Three different buffering solutions were used for these tests: trisodium phosphate (TSP), sodium hydroxide, and sodium tetraborate. These pH control agents used following a LOCA at a nuclear power plant show various degrees of interaction with the insulating materials Cal-Sil and NUKON. Results for Cal-Sil dissolution tests in TSP solutions, settling rate tests of calcium phosphate precipitates, and benchmark tests in chemically inactive environments are also presented. The dissolution tests were intended to identify important environmental variables governing both calcium dissolution and subsequent calcium phosphate formation over a range of simulated sump pool conditions. The results from the dissolution testing were used to inform both the head loss and settling test series. The objective of the head loss tests was to assess the head loss produced by debris beds created by Cal-Sil, fibrous debris, and calcium phosphate precipitates. The effects of both the relative arrival time of the precipitates and insulation debris and the calcium phosphate formation process were specifically evaluated. The debris loadings, test loop flow rates, and test temperature were chosen to be reasonably representative of …
Date:
October 31, 2006
Creator:
Park, J. H.; Kasza, K.; Fisher, B.; Oras, J.; Natesan, K.; Shack, W. J. et al.
Object Type:
Report
System:
The UNT Digital Library
Methods for high precision 14C AMS measurement of atmospheric CO2 at LLNL
Development of {sup 14}C analysis with precision better than 2{per_thousand} has the potential to expand the utility of {sup 14}CO{sub 2} measurements for carbon cycle investigations as atmospheric gradients currently approach traditional measurement precision of 2-5{per_thousand}. The AMS facility at the Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, produces high and stable beam currents that enable efficient acquisition times for large numbers of {sup 14}C counts. One million {sup 14}C atoms can be detected in approximately 25 minutes, suggesting that near 1{per_thousand} counting precision is economically feasible at LLNL. The overall uncertainty in measured values is ultimately determined by the variation between measured ratios in several sputtering periods of the same sample and by the reproducibility of replicate samples. Experiments on the collection of one million counts on replicate samples of CO{sub 2} extracted from a whole air cylinder show a standard deviation of 1.7{per_thousand} in 36 samples measured over several wheels. This precision may be limited by the reproducibility of Oxalic Acid I standard samples, which is considerably poorer. We outline the procedures for high-precision sample handling and analysis that have enabled reproducibility in the cylinder extraction samples at the <2{per_thousand} level and describe future directions to …
Date:
October 18, 2006
Creator:
Graven, H D; Guilderson, T P & Keeling, R F
Object Type:
Article
System:
The UNT Digital Library
LHC Olympics Workshop and String Phenomenology 2006 Conference
This is the final report of the organizers of the String Phenomenolgy program of which the LHC Olympics and the String Phenomenolgy conference were a part. In addition, it includes the list of talks from our website which comprise the online proceedings. The KITP no longer publishes conferences proceedings but rather makes recordings and visuals of all talks available on its website at www.kitp.ucsb.edu Program talks are available at http://online.kitp.ucsb.edu/online/strings06/ Conference talks are are at http://online.itp.ucsb.edu/online/strings_c06/ and LHC Olympics talks are at http://online.itp.ucsb.edu/online/lhco_c06/. These talks constitute the proceedings of these meetings.
Date:
October 1, 2006
Creator:
Gross, David
Object Type:
Article
System:
The UNT Digital Library
Microbial Transformations of Radionuclides Released From Nuclear Fuel Reprocessing Plants.
Microorganisms can affect the stability and mobility of the actinides U, Pu, Cm, Am, Np, and the fission products Tc, I, Cs, Sr, released from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been investigated, we have only limited information on the effects of microbial processes. The mechanisms of microbial transformations of the major and minor actinides and the fission products under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed.
Date:
October 18, 2006
Creator:
Francis, A. J.
Object Type:
Article
System:
The UNT Digital Library
Long term biosustainability in a high energy, low diversity crustal biome
Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities for millions of years with no apparent reliance on photosynthetically derived substrates.
Date:
October 1, 2006
Creator:
Lin, L-H.; Wang, P-L.; Rumble, D.; Lippmann-Pipke, J.; SherwoodLollar, B.; Boice, E. et al.
Object Type:
Article
System:
The UNT Digital Library
Photon Production through Multi-step Processes Important in Nuclear Fluorescence Experiments
The authors present calculations describing the production of photons through multi-step processes occurring when a beam of gamma rays interacts with a macroscopic material. These processes involve the creation of energetic electrons through Compton scattering, photo-absorption and pair production, the subsequent scattering of these electrons, and the creation of energetic photons occurring as these electrons are slowed through Bremsstrahlung emission. Unlike single Compton collisions, during which an energetic photon that is scattered through a large angle loses most of its energy, these multi-step processes result in a sizable flux of energetic photons traveling at large angles relative to an incident photon beam. These multi-step processes are also a key background in experiments that measure nuclear resonance fluorescence by shining photons on a thin foil and observing the spectrum of back-scattered photons. Effective cross sections describing the production of backscattered photons are presented in a tabular form that allows simple estimates of backgrounds expected in a variety of experiments. Incident photons with energies between 0.5 MeV and 8 MeV are considered. These calculations of effective cross sections may be useful for those designing NRF experiments or systems that detect specific isotopes in well-shielded environments through observation of resonance fluorescence.
Date:
October 26, 2006
Creator:
Hagmann, C & Pruet, J
Object Type:
Article
System:
The UNT Digital Library
PERC 2 High-End Computer System Performance: Scalable Science and Engineering
During two years of SciDAC PERC-2, our activities had centered largely on development of new performance analysis techniques to enable efficient use on systems containing thousands or tens of thousands of processors. In addition, we continued our application engagement efforts and utilized our tools to study the performance of various SciDAC applications on a variety of HPC platforms.
Date:
October 15, 2006
Creator:
Reed, Daniel
Object Type:
Report
System:
The UNT Digital Library
University/NETL Student Partnership Program
The University/National Energy Technology Laboratory (NETL) Student Partnership Program stimulated basic and applied research in Energy and Environmental Science areas through NETL's Office of Science and Technology (OST). This Partnership Program supported the education of graduate students in Energy and Environmental Sciences, while fostering increased scientific interaction between NETL and the participating universities, by providing graduate student support for research at a NETL facility under the joint supervision of NETL and university faculty. Projects were intended to enhance a previously established scientific or engineering relationship or to create a new relationship. Major areas of research under the Partnership Program included CO{sub 2} sequestration, granular solids flow, multi-phase flow in porous solids, gas hydrates, nanotubes, acid-mine flow identification and remediation, water-gas shift reaction, circulating fluidized beds, slurry bubble column, fuel desulphurization, carbon fibers, and fuel cells.
Date:
October 31, 2006
Creator:
Holder, Gerald; Mathews, Jonathan; Wilson, Thomas; Chuang, Steven; Amon, Cristina; Ertekin, Turgay et al.
Object Type:
Report
System:
The UNT Digital Library
The Role of Nuclear Motion in the Photo-Double Ionization ofMolecular Hydrogen
We examine the origin of recently observed variations with internuclear distance (R) of the fully differential cross sections for double ionization of aligned H2 by absorption of a single photon. Using the results of fully converged numerical solutions of the Schroedinger equation, we show that these variations arise primarily from pronounced differences in the R-dependence of the parallel and perpendicular components of the ionization amplitude. We also predict that R-dependences should be readily observable in the asymmetry parameter for photo-double ionization, even in experimental measurements that are not differential in the energy sharings between ejected photo-electrons.
Date:
October 26, 2006
Creator:
Horner, Daniel A.; Vanroose, Wim; Rescigno, Thomas N.; Martin,Fernando & McCurdy, C. William
Object Type:
Article
System:
The UNT Digital Library
Aerosol sample preparation methods for X-ray diffractive imaging: Size-selected spherical nanoparticles on silicon nitride foils
None
Date:
October 23, 2006
Creator:
Bogan, M. J.; Benner, W. H.; Hau-Riege, S.; Chapman, H. & Frank, M.
Object Type:
Article
System:
The UNT Digital Library
Simple Models and Methods for Estimating the UltrasonicReflectivity of Spot Welds
This paper describes models and methods for estimating theacoustic reflectivity of the welded interfaces between spot-welded sheetsfrom normal-incidence pulse-echo ultrasound signals. The simple geometryof the problem allows an abstraction that does not resort to complex waveequations. Instead, a reflectivity model predicts the timing andamplitude of the echoes arriving at the probe. This reflectivity model isnested in a signal processing model; recovering reflectivity firstrequires deconvolution to recover discrete impulses from the probesignal, then processing these with the reflectivity model. Reflectivitymaps of spot welds generated with this model show promise for predictingweld quality.
Date:
October 15, 2006
Creator:
Davis, William B.
Object Type:
Article
System:
The UNT Digital Library
Orbital HP-Clouds for Solving Schrödinger Equation in Quantum Mechanics
Solving Schroedinger equation in quantum mechanics presents a challenging task in numerical methods due to the high order behavior and high dimension characteristics in the wave functions, in addition to the highly coupled nature between wave functions. This work introduces orbital and polynomial enrichment functions to the partition of unity for solution of Schroedinger equation under the framework of HP-Clouds. An intrinsic enrichment of orbital function and extrinsic enrichment of monomial functions are proposed. Due to the employment of higher order basis functions, a higher order stabilized conforming nodal integration is developed. The proposed methods are implemented using the density functional theory for solution of Schroedinger equation. Analysis of several single and multi-electron/nucleus structures demonstrates the effectiveness of the proposed method.
Date:
October 19, 2006
Creator:
Chen, J. S.; Hu, W. & Puso, M. A.
Object Type:
Article
System:
The UNT Digital Library
Fall Chinook Salmon Spawning Ground Surveys in the Snake River Basin Upriver of Lower Granite Dam, 2005 Annual Report.
Redd counts are routinely used to document the spawning distribution of fall Chinook salmon (Oncorhynchus tshawytscha) in the Snake River basin upriver of Lower Granite Dam. The first reported redd counts were from aerial searches conducted intermittently between 1959 and 1978 (Irving and Bjornn 1981, Witty 1988; Groves and Chandler 1996)(Appendix 1). In 1986, the Washington Department of Fish and Wildlife began an annual monitoring program that, in addition to the Snake River, included aerial searches of the Grande Ronde River the first year (Seidel and Bugert 1987), and the Imnaha River in subsequent years (Seidel et al. 1988; Bugert et al. 1989-1991; Mendel et al. 1992). The U. S. Fish and Wildlife Service and Idaho Power Company began contributing to this effort in 1991 by increasing the number of aerial searches conducted each year and adding underwater searches in areas of the Snake River that were too deep to be searched from the air (Connor et al. 1993; Garcia et al. 1994a, 1994b, 1996-2005; Groves 1993; Groves and Chandler 1996). The Nez Perce Tribe added aerial searches in the Clearwater River basin beginning in 1988 (Arnsberg et. al 1992), and the Salmon River beginning in 1992. Currently searches are …
Date:
October 1, 2006
Creator:
Garcia, A. P.; Bradbury, S.; Arnsberg, B.D.; Rocklage, S.J. & Groves, P.A.
Object Type:
Report
System:
The UNT Digital Library
Evaluation and Characterization of Magnets and Capacitors
Advanced vehicle, fuel cell, hybrid electric vehicle (HEV), and plug in hybrid research and development is conducted by the U.S. Department of Energy (DOE) through its FreedomCAR and Vehicle Technologies (FCVT) program. The mission of this program is to develop more energy efficient and environmentally safe highway transportation technologies. Program activities include research, development, testing, technology validation, and technology transfer. These activities are done at the system and component levels. This report will discuss component level testing of prototype capacitors and magnets. As capacitor and magnet technologies mature, it is important to ascertain the limitations of these new technologies by subjecting the components to standardized tests to evaluate their capabilities. Test results will assist in the determination of their ability to provide improvements in power electronics and motor designs to meet the FCVT goals.
Date:
October 15, 2006
Creator:
Seiber, L. E.; Cunningham, J. P.; Golik, S. S. & Armstrong, G.
Object Type:
Report
System:
The UNT Digital Library
New Phases of Hydrogen-Bonded Systems at Extreme Conditions
We study the behavior of hydrogen-bonded systems under high-pressure and temperature. First principle calculations of formic acid under isotropic pressure up to 70 GPa reveal the existence of a polymerization phase at around 20 GPa, in support of recent IR, Raman, and XRD experiments. In this phase, covalent bonding develops between molecules of the same chain through symmetrization of hydrogen bonds. We also performed molecular dynamics simulations of water at pressures up to 115 GPa and 2000 K. Along this isotherm, we are able to define three different phases. We observe a molecular fluid phase with superionic diffusion of the hydrogens for pressure 34 GPa to 58 GPa. We report a transformation to a phase dominated by transient networks of symmetric O-H hydrogen bonds at 95-115 GPa. As in formic acid, the network can be attributed to the symmetrization of the hydrogen bond, similar to the ice VII to ice X transition.
Date:
October 23, 2006
Creator:
Manaa, M R; Goldman, N & Fried, L E
Object Type:
Article
System:
The UNT Digital Library
Olivine-FeS Partial-Melt
The figure shows Fe-S-filled melt channels in olivine created at high temperature and pressure. The 3D image was obtained on Beamline 8.3.2 at the Advanced Light Source, Lawrence Berkeley Laboratory, with a spatial resolution of better than two microns (bar is 10 microns). Permeability of Fe-S melts in olivine at high temperatures and pressures provides an important constraint on models of planetary core formation. Permeability must be inferred from empirical relationships based on microstructure. To date, estimates of permeability have varied by more than five orders of magnitude. To provide more accurate constraints, we used high-resolution synchrotron radiation computed tomography to image the three-dimensional network of melt-containing pores in an olivine matrix, and calculated the permeability directly by solving the equations of Stokes flow through the actual pore network using a lattice-Boltzmann approach. These calculations provide an independent constraint on models of planetary core formation.
Date:
October 2, 2006
Creator:
Roberts, J.; Siebert, J.; Ryerson, F. J. & Kinney, J.
Object Type:
Article
System:
The UNT Digital Library
A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHCEnergies
Standard jet finding techniques used in elementary particle collisions have not been successful in the high track density of heavy-ion collisions. This paper describes a modified cone-type jet finding algorithm developed for the complex environment of heavy-ion collisions.
Date:
October 1, 2006
Creator:
Blyth, S.-L.; Horner, M.J.; Awes, T.; Cormier, T.; Gray, H.; Klay, J.L. et al.
Object Type:
Article
System:
The UNT Digital Library
Comment on "Paleoclassical Transport in Low-Collisionality Toroidal Plasmas"
Paleoclassical transport [1] is a recently proposed fundamental process that is claimed to occur in resistive plasmas and to be missing in the collisional drift-kinetic equations (DKE) in standard use. In this Comment we raise three puzzles presented by paleoclassical transport as developed in [1], one to do with conservation and two concerning uniqueness.
Date:
October 13, 2006
Creator:
LoDestro, L. L.
Object Type:
Article
System:
The UNT Digital Library
Design and Status of RERTR Irradiation Tests in the Advanced Test Reactor
Irradiation testing of U-Mo based fuels is the central component of the Reduced Enrichment for Research and Test Reactors (RERTR) program fuel qualification plan. Several RERTR tests have recently been completed or are planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory in Idaho Falls, ID. Four mini-plate experiments in various stages of completion are described in detail, including the irradiation test design, objectives, and irradiation conditions. Observations made during and after the in-reactor RERTR-7A experiment breach are summarized. The irradiation experiment design and planned irradiation conditions for full-size plate test are described. Progress toward element testing will be reviewed.
Date:
October 1, 2006
Creator:
Wachs, Daniel M.; Ambrosek, Richard G.; Chang, Gray & Meyer, Mitchell K.
Object Type:
Article
System:
The UNT Digital Library
Spectral Decomposition of Signaling Networks
None
Date:
October 1, 2006
Creator:
Parvin, Bahram; Ghosh, Nimu; Heiser, Laura; Knapp, M.; Talcott,C.; Laderoute, K. et al.
Object Type:
Article
System:
The UNT Digital Library