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Alternatives to conventional diesel fuel-some potential implications of California's TAC decision on diesel particulate.

Description: Limitations on the use of petroleum-based diesel fuel in California could occur pursuant to the 1998 declaration by California's Air Resources Board (CARB) that the particulate matter component of diesel exhaust is a carcinogen, therefore a toxic air contaminant (TAC) subject to provisions of the state's Proposition 65. It is the declared intention of CARB not to ban or restrict diesel fuel, per se, at this time. Assuming no total ban, Argonne National Laboratory (ANL) explored two feasible ''mid-course'' strategies. (1) Increased penetration of natural gas and greater gasoline use in the transportation fuels market, to the extent that some compression-ignition (CI) applications revert to spark-ignition (SI) engines. (2) New specifications requiring diesel fuel reformulation based on exhaust products of individual diesel fuel constituents. Each of these alternatives results in some degree of (conventional) diesel displacement. In the first case, diesel fuel is assumed admissible for ignition assistance as a pilot fuel in natural gas (NG)-powered heavy-duty vehicles, and gasoline demand in California increases by 32.2 million liters per day overall, about 21 percent above projected 2010 baseline demand. Natural gas demand increases by 13.6 million diesel liter equivalents per day, about 7 percent above projected (total) consumption level. In the second case, compression-ignition engines utilize substitutes for petroleum-based diesel having similar ignition and performance properties. For each case we estimated localized air emission plus generalized greenhouse gas and energy changes. Economic implications of vehicle and engine replacement were not evaluated.
Date: August 10, 1999
Creator: Eberhardt, J. J.; Rote, D. M.; Saricks, C. L. & Stodolsky, F.
Partner: UNT Libraries Government Documents Department

Microstructural development in waste form alloys cast from irradiated cladding residual from the electrometallurgical treatment of EBR-II spent fuel.

Description: A metallic waste form alloy that consists primarily of stainless steel and zirconium is being developed by Argonne National Laboratory to contain metallic waste constituents that are residual from an electrometallurgical treatment process for spent nuclear fuel. Ingots have been cast in an induction furnace in a hot cell using actual, leftover, irradiated, EBR-II cladding hulls treated in an electrorefiner. The as-cast ingots have been sampled using a core-drilling and an injection-casting technique. In turn, generated samples have been characterized using chemical analysis techniques and a scanning electron microscope equipped with energy dispersive and wavelength-dispersive spectrometers. As-cast ingots contain the predicted concentration levels of the various constituents, and most of the phases that develop are analogous to those for alloys generated using non-radioactive surrogates for the various fission products.
Date: June 10, 1999
Creator: Keiser, D. D., Jr.
Partner: UNT Libraries Government Documents Department

Application of the FD-TD method to the electromagnetic modeling of patch antenna arrays

Description: FD-TD method and the Berenger Perfectly Matched Layer (PML) absorbing condition are applied to the modeling of a 32-element patch array. Numerical results for the return loss at the array feed are presented and compared to measured results for the purpose of model validation.
Date: January 10, 1996
Creator: Pasik, M.F.; Aguirre, G. & Cangellaris, A.C.
Partner: UNT Libraries Government Documents Department

Vicarious amination of nitroarenes with trimethylhydrazinium iodine

Description: This paper investigated the use of 1,1,1-trimethylhydrazinium iodide as a vicarious nucleophilic substitution reagent for introducing amino groups into nitroaromatic substrates. The substrates included nitroarenes, polynitrobenzenes, picramide, TNB,TNT, and dinitropyrazole; other nitroazoles are being studied.
Date: November 10, 1995
Creator: Pagoria, P.F.; Schmidt, R.D. & Mitchell, A.R.
Partner: UNT Libraries Government Documents Department

Advanced biochemical processes for geothermal brines current developments

Description: A research program at Brookhaven National Laboratory (BNL) which deals with the development and application of processes for the treatment of geothermal brines and sludges has led to the identification and design of cost-efficient and environmentally friendly treatment methodology. Initially the primary goal of the processing was to convert geothermal wastes into disposable materials whose chemical composition would satisfy environmental regulations. An expansion of the R&D effort allowed to identify a combination of biochemical and chemical processes which became a basis for the development of a technology for the treatment of geothermal brines and sludges. The new technology satisfies environmental regulatory requirements and concurrently converts the geothermal brines and sludges into commercially promising products. Because the chemical composition of geothermal wastes depends on the type of the resource and therefore differs, the emerging technology has to be also flexible so that it can be readily modified to suit the needs of a particular type of resource. Recent conceptional designs for the processing of hypersaline and low salinity brines and sludges will be discussed.
Date: March 10, 1997
Creator: Premuzic, E.T.; Lin, M.S. & Bohenek, M.
Partner: UNT Libraries Government Documents Department

3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes

Description: We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and axial planes. The resultant volumetric image data, consisting of fluorescence intensities for typically {approximately}50 million voxels in XYZ space, can be used to reconstruct the three-dimensional structure of the two-phase medium. We present several examples of this application, including studying pore geometry in sandstone, characterizing brittle failure processes in low-porosity rock deformed under triaxial loading conditions in the laboratory, and analyzing the microstructure of porous ceramic insulations. We then describe approaches to extract statistical microgeometric descriptions from volumetric image data, and present results derived from confocal volumetric data sets. Finally, we develop the use of confocal image data to automatically generate a three-dimensional mesh for numerical pore-scale flow simulations.
Date: February 10, 1999
Creator: Fredrich, J.T.
Partner: UNT Libraries Government Documents Department

Multilayer reflective coatings for extreme-ultraviolet lithography

Description: Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These improvements in EUV multilayer mirror technology will enable us to meet the stringent specifications for coating the large optical substrates for our next-generation EUV lithography system.
Date: March 10, 1998
Creator: Montcalm, C., LLNL
Partner: UNT Libraries Government Documents Department

Back-Contact Crystalline-Silicon Solar Cells and Modules

Description: This paper summarizes recent progress in the development of back-contact crystalline-silicon (c-Si) solar cells and modules at Sandia National Laboratories. Back-contact cells have potentially improved efficiencies through the elimination of grid obscuration and allow for significant simplifications in the module assembly process. Optimization of the process sequence has improved the efficiency of our back-contact cell (emitter wrap through) from around 12% to near 17% in the past 12 months. In addition, recent theoretical work has elucidated the device physics of emitter wrap-through cells. Finally, improvements in the assembly processing back-contact cells are described.
Date: March 10, 1999
Creator: Bode, M.D.; Garrett, S.E.; Gee, J.M.; Jimeno, J.C. & Smith, D.D.
Partner: UNT Libraries Government Documents Department

Beam rounders for circular colliders

Description: By means of linear optics, an arbitrary uncoupled beam can be locally transformed into a round (rotation-invariant) state and then back. This provides an efficient way to round beams in the interaction region of circular colliders.
Date: December 10, 2002
Creator: Nagaitsev, A. Burov and S.
Partner: UNT Libraries Government Documents Department

Beauty and charm production at fixed-target experiments

Description: Fixed-target experiments continue to provide insights into the physics of particle production in strong interactions. The experiments are performed with different types of beam particles of varying energies, and many different target materials. Studies of beauty and charm production are of particular interest, since experimental results can be compared to perturbative QCD calculations. It is in this context that recent results from fixed-target experiments on beauty and charm production will be reviewed.
Date: December 10, 2003
Creator: Gottschalk, Erik E.
Partner: UNT Libraries Government Documents Department

Status of the CDF Run II Silicon Detector

Description: A snapshot of the status of the CDF Run II Silicon Detector is presented, with a summary of commissioning issues since the start of Run II, current performance of the detector, and the use of the data in both the trigger and offline reconstruction.
Date: April 10, 2003
Creator: Nahn, S.
Partner: UNT Libraries Government Documents Department

RECENT SNO RESULTS.

Description: Solar Neutrinos from the decay of {sup 8}B have been detected at the Sudbury Neutrino Observatory (SNO) by charged current (CC) and neutral current (NC) interactions on deuterium and elastic scattering (ES) of electrons. The SNO data indicate that with the assumption of undistorted {sup 8}B shape, the flux for v{sub e} is {phi}{sub e} = 1.76{sub -0.05}{sup +0.05}(stat.){sub -0.09}{sup +0.09}(syst.) x 10{sup 6} cm{sup -2} s{sup -1} for a kinetic energy threshold of 5 MeV. The non-v{sub e} flux is {phi}{sub {mu}{tau}} = 3.41{sub -0.45}{sup +0.45}(stat.){sub -0.45}{sup +0.48}(syst.) x 10{sup 6} cm{sup -2}s{sup -1}. This provides strong evidence for solar v{sub e} flavor transformation. The day and night solar neutrino energy spectra and rates have also been measured. For CC events, the v{sub e} asymmetry is 14.0% {+-} 6.3%{sub -1.4}{sup +1.5}%. By additionally constraining the total (NC) flux of active neutrinos to have no asymmetry, the v{sub e} asymmetry becomes 7.0% {+-} 4.9%{sub -1.2}{sup +1.3}%. A global solar neutrino analysis strongly favors the Large Mixing Angle (LMA) solution in a two-flavor neutrino oscillation model.
Date: December 10, 2002
Creator: YEH,M.
Partner: UNT Libraries Government Documents Department

The readout of the LHC beam luminosity monitor: Accurate shower energy measurements at a 40 MHz repetition rate

Description: The LHC beam luminosity monitor is based on the following principle. The neutrals that originate in LHC at every PP interaction create showers in the absorbers placed in front of the cryogenic separation dipoles. The shower energy, as it can be measured by suitable detectors in the absorbers is proportional to the number of neutral particles and, therefore, to the luminosity. This principle lends itself to a luminosity measurement on a bunch-by-bunch basis. However, detector and front-end electronics must comply with extremely stringent requirements. To make the bunch-by-bunch measurement feasible, their speed of operation must match the 40 MHz bunch repetition rate of LHC. Besides, in the actual operation the detector must stand extremely high radiation doses. The front-end electronics, to survive, must be located at some distance from the region of high radiation field, which means that a properly terminated, low-noise, cable connection is needed between detector and front-end electronics. After briefly reviewing the solutions that have been adopted for the detector and the front-end electronics and the results that have been obtained so far in tests on the beam, the latest version of the instrument in describe in detail. It will be shown how a clever detector design, a suitable front-end conception based on the use of a ''cold resistance'' cable termination and a careful low-noise design, along with the use of an effective deconvolution algorithm, make the luminosity measurement possible on a bunch-by-bunch basis at the LHC bunch repetition rates.
Date: May 10, 2003
Creator: Manfredi, P.F.; Ratti, L.; Speziali, V.; Traversi, G.; Manghisoni, M.; Re, V. et al.
Partner: UNT Libraries Government Documents Department

Antiproton acceleration in the Fermilab Main Injector using 2.5 MHz (H=28) and 53 MHz (H=588) rf systems

Description: During the Run II era at Fermilab, the Recycler stores antiprotons at 8 GeV and the Main Injector accelerates the antiprotons and the protons from 8 GeV to 150 GeV for Tevatron injection. The Recycler injects antiprotons to the Main Injector in 2.5 MHz rf buckets. This report presents an acceleration scheme for the antiprotons that involves a slow ramp with initial 2.5 MHz acceleration and subsequent fast acceleration with 53 MHz rf system. Beam acceleration and rf manipulation with space charge and beam loading effects are simulated using the longitudinal simulation code ESME. Simulation suggests that one can expect about 15% emittance growth for the entire acceleration cycle with beam loading compensations. Preliminary experimental results with proton beam will also be presented.
Date: June 10, 2003
Creator: al., Vincent Wu et
Partner: UNT Libraries Government Documents Department

Modeling of geochemical interactions between acidic and neutral fluids in the Onikobe Geothermal Reservoir

Description: Two types of fluids are encountered in the Onikobe geothermal reservoir, one is neutral and the other is acidic (pH=3). It is hypothesized that acidic fluid might be upwelling along a fault zone and that an impermeable barrier might be present between the acidic and neutral fluid zones. We carried out reactive geothermal transport simulations using TOUGHREACT (Xu and Pruess, 1998 and 2001) to test such a conceptual model. One-dimensional models were used to study the geochemical behavior due to mixing of the two fluids. Mn-rich smectite precipitated near the mixing front and is likely to form an impermeable barrier between regions with acidic and neutral fluids.
Date: January 10, 2003
Creator: Todaka, Norifumi; Akasaka, Chitoshi; Xu, Tianfu & Pruess, Karsten
Partner: UNT Libraries Government Documents Department

Programming Robots with Associative Memories

Description: Today, there are several drawbacks that impede the necessary and much needed use of robot learning techniques in real applications. First, the time needed to achieve the synthesis of any behavior is prohibitive. Second, the robot behavior during the learning phase is � by definition � bad, it may even be dangerous. Third, except within the lazy learning approach, a new behavior implies a new learning phase. We propose in this paper to use self-organizing maps to encode the non explicit model of the robot-world interaction sampled by the lazy memory, and then generate a robot behavior by means of situations to be achieved, i.e., points on the self-organizing maps. Any behavior can instantaneously be synthesized by the definition of a goal situation. Its performance will be minimal (not evidently bad) and will improve by the mere repetition of the behavior.
Date: July 10, 1999
Creator: Touzet, C.
Partner: UNT Libraries Government Documents Department

Higgs searches at the Tevatron

Description: One of the highest priority physics goals for the upgraded Tevatron experiments, CDF and D0, is the search for the Higgs boson. We present the initial results from both experiments, based on 40-90 pb{sup -1} integrated luminosity, of Higgs searches in several final states, including WH and ZH, H {yields} WW, and doubly-charged Higgs.
Date: June 10, 2003
Creator: Li, Qizhong
Partner: UNT Libraries Government Documents Department

Shadowing effects on vector boson production

Description: We explore how nuclear modifications to the nucleon structure functions, shadowing, affect massive gauge boson production in heavy ion collisions at different impact parameters. We calculate the dependence of Z{sup 0}, W{sup +} and W{sup -} production on rapidity and impact parameter to next-to-leading order in Pb+Pb collisions at 5.5 TeV/nucleon to study quark shadowing at high Q{sup 2}. We also compare our Pb+Pb results to the pp rapidity distributions at 14 TeV.
Date: November 10, 2000
Creator: Vogt, R.
Partner: UNT Libraries Government Documents Department