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Strangeness production in minimum-bias events at CDF

Description: In a recently published paper 1 are emphasized, for the soft subsample extracted from the minimum-bias (MB) dataset of p{bar p} collisions, interesting invariances with the c.m. energy of the charged multiplicity and p{sub T} distributions. We present an analogous study on V{sup 0} production.
Date: January 15, 2003
Creator: Moggi, N.
Partner: UNT Libraries Government Documents Department

On-Line Measurements of Beryllium, Chromium, and Mercury by Using Aerosol Beam Focused Laser-Induced Plasma Spectrometer and Time-Integrated Filter Sampling Reference Method

Description: A novel real-time monitor for aerosol particles has been developed by the Oak Ridge National Laboratory (ORNL). The instrument is designed to perform in-situ measurement for the elemental composition of aerosol particles in flue gas. We had tested this monitor at the Eastman Chemical Company in July 2001 taking advantage of the emissions from a waste incinerator operated by the company as the background. To investigate the behavior and response of the monitor under simulated/known conditions, stock solutions of prepared metal concentration(s) were nebulized to provide spikes for the instrument testing. Strengths of the solutions were designed such that a reference method (RM) was able to collect sufficient material on filter samples that were subsequently analyzed in a laboratory to produce 30-minute average data points. Parallel aerosol measurements were performed by using the ORNL instrument. Recorded signal of an individual element was processed and the concentration calculated from a calibration curve established prior to the campaign. RM data were able to reflect the loads simulated in the spiked waste stream. However, it missed one beryllium sample. The possibility of bias exists in the RM determination of chromium that could lead to erroneous comparison between the RM and the real-time monitoring data. With the real-time detection capability, the ORNL instrument was able to reveal the emission variation by making seven measurements within a 30-minute cycle. The ability of the instrument also enables the reconstruction of the baseline chromium emission concentration. The measurements for mercury by both methods are in good agreement.
Date: May 15, 2003
Creator: Cheng, M.D.
Partner: UNT Libraries Government Documents Department

Comparing geophysical measurements to theoretical estimates for soil mixtures at low pressures

Description: The authors obtained good estimates of measured velocities of sand-peat samples at low pressures by using a theoretical method, the self-consistent theory of Berryman (1980), using sand and porous peat to represent the microstructure of the mixture. They were unable to obtain useful estimates with several other theoretical approaches, because the properties of the quartz, air and peat components of the samples vary over several orders of magnitude. Methods that are useful for consolidated rock cannot be applied directly to unconsolidated materials. Instead, careful consideration of microstructure is necessary to adapt the methods successfully. Future work includes comparison of the measured velocity values to additional theoretical estimates, investigation of Vp/Vs ratios and wave amplitudes, as well as modeling of dry and saturated sand-clay mixtures (e.g., Bonner et al., 1997, 1998). The results suggest that field data can be interpreted by comparing laboratory measurements of soil velocities to theoretical estimates of velocities in order to establish a systematic method for predicting velocities for a full range of sand-organic material mixtures at various pressures. Once the theoretical relationship is obtained, it can be used to estimate the soil composition at various depths from field measurements of seismic velocities. Additional refining of the method for relating velocities to soil characteristics is useful for development inversion algorithms.
Date: January 15, 1999
Creator: Wildenschild, D; Berge, P A; Berryman, K G; Bonner, B P & Roberts, J J
Partner: UNT Libraries Government Documents Department

Constructing Integrable High-pressure Full-current Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions

Description: For the (non-axisymmetric) stellarator class of plasma confinement devices to be feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux surfaces; however, the inherent lack of a continuous symmetry implies that magnetic islands responsible for breaking the smooth topology of the flux surfaces are guaranteed to exist. Thus, the suppression of magnetic islands is a critical issue for stellarator design, particularly for small aspect ratio devices. Pfirsch-Schluter currents, diamagnetic currents, and resonant coil fields contribute to the formation of magnetic islands, and the challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary high-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the Princeton Iterative Equilibrium Solver [Reiman and Greenside, Comp. Phys. Comm. 43 (1986) 157] which iterate s the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to preserve certain measures of engineering acceptability and to preserve the stability of ideal kink modes. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible, the plasma is stable to ideal kink modes, and the coils satisfy engineering constraints. The method is applied to a candidate plasma and coil design for the National Compact Stellarator Experiment [Reiman, et al., Phys. Plasmas 8 (May 2001) 2083].
Date: September 15, 2003
Creator: Hudson, S.R.; Monticello, D.A.; Reiman, A.H.; Strickler, D.J.; Hirshman, S.P.; Ku, L-P. et al.
Partner: UNT Libraries Government Documents Department

Laser Acoustic Microstructure Analysis at the Micron and Nanometer Length Scale

Description: Laser acoustic approaches to investigating the interaction of elastic waves with microstructure in materials is presented that probe both the micron and nanometer length scales. At the micron length scale, a full-field imaging approach is described that provides quantitative measurement of amplitude and phase of the out-of-plane acoustical motion at GHz frequencies. Specific lateral acoustic modes can be identified in addition to the primary thickness mode with spatial resolution sufficient to image wavelengths as small as 4.5 microns.
Date: May 15, 2002
Creator: Telschow, K.L. & Hurley, D.H.
Partner: UNT Libraries Government Documents Department

Prospects of discovery for supersymmetry at the Tevatron

Description: We summarize a discovery potential for supersymmetric particles at the p{bar p} collider of Tevatron with center-of-mass energy {radical}s = 2 TeV and integrated luminosity {integral} L dt = 15-30 fb{sup -1}. Any direct search is kinematically limited to below 450 GeV/c{sup 2}. We, however, have a unique opportunity to test various supersymmetric scenarios by a measurement of the branching ratio for the rare decay mode B{sub s} {yields} {mu}{sup +}{mu}{sup -}. Using the background estimate in the CDF analysis of B{sub s} {yields} {mu}{sup +}{mu}{sup -} in Run I, we investigate the prospects for studying this mode in Run II. CDF would be sensitive to this decay for a branching ratio > 1.2 x 10{sup -8} with 15 fb{sup -1} (or, if a similar analysis holds for D0, > 6.5 x 10{sup -9} for the combined data). For tan {beta} > 30, the B{sub s} {yields} {mu}{sup +}{mu}{sup -} search can probe the SUSY parameter space that cannot be probed by direct production of SUSY particles at Run II. An observation of B{sub s} {yields} {mu}{sup +}{mu}{sup -} with a large branching ratio > 7(14) x 10{sup -8} (feasible with only 2 fb{sup -1}) would be sufficient to exclude the mSUGRA model for tan {beta} {le} 50(55) including other experimental constraints. For some models, the branching ratio can be large enough to be detected even for small tan {beta} and large m{sub 1/2}.
Date: January 15, 2003
Creator: Kamon, T.
Partner: UNT Libraries Government Documents Department

SPINning parallel systems software.

Description: We describe our experiences in using Spin to verify parts of the Multi Purpose Daemon (MPD) parallel process management system. MPD is a distributed collection of processes connected by Unix network sockets. MPD is dynamic processes and connections among them are created and destroyed as MPD is initialized, runs user processes, recovers from faults, and terminates. This dynamic nature is easily expressible in the Spin/Promela framework but poses performance and scalability challenges. We present here the results of expressing some of the parallel algorithms of MPD and executing both simulation and verification runs with Spin.
Date: March 15, 2002
Creator: Matlin, O.S.; Lusk, E. & McCune, W.
Partner: UNT Libraries Government Documents Department

PCR+ In Diesel Fuels and Emissions Research

Description: In past work for the U.S. Department of Energy (DOE) and Oak Ridge National Laboratory (ORNL), PCR+ was developed as an alternative methodology for building statistical models. PCR+ is an extension of Principal Components Regression (PCR), in which the eigenvectors resulting from Principal Components Analysis (PCA) are used as predictor variables in regression analysis. The work was motivated by the observation that most heavy-duty diesel (HDD) engine research was conducted with test fuels that had been ''concocted'' in the laboratory to vary selected fuel properties in isolation from each other. This approach departs markedly from the real world, where the reformulation of diesel fuels for almost any purpose leads to changes in a number of interrelated properties. In this work, we present new information regarding the problems encountered in the conventional approach to model-building and how the PCR+ method can be used to improve research on the relationship between fuel characteristics and engine emissions. We also discuss how PCR+ can be applied to a variety of other research problems related to diesel fuels.
Date: April 15, 2002
Creator: McAdams, H.T.
Partner: UNT Libraries Government Documents Department

HIGH SO2 REMOVAL EFFICIENCY TESTING

Description: This final report describes the results of performance tests at six full-scale wet lime- and limestone-reagent flue gas desulfurization (FGD) systems. The objective of these tests was to evaluate the effectiveness of low capital cost sulfur dioxide (SO{sub 2}) removal upgrades for existing FGD systems as an option for complying with the provisions of the Clean Air Act Amendments of 1990. The upgrade options tested at the limestone-reagent systems included the use of organic acid additives (dibasic acid (DBA) and/or sodium formate) as well as increased reagent ratio (higher excess limestone levels in the recirculating slurry solids) and absorber liquid-to-gas ratio. One system also tested operating at higher flue gas velocities to allow the existing FGD system to treat flue gas from an adjacent, unscrubbed unit. Upgrade options for the one lime-based system tested included increased absorber venturi pressure drop and increased sulfite concentration in the recirculating slurry liquor.
Date: October 15, 1997
Creator: Blythe, Gary M. & Phillips, James L.
Partner: UNT Libraries Government Documents Department

Analysis of Tank 43H Samples at the Conclusion of Uranyl Carbonate Addition

Description: Tank 43H serves as the feed Tank to the 2H evaporator. In the months of July and August 2001, about 21,000 gallons of a depleted uranyl carbonate solution were added to Tank 43H and agitated with two Flygt mixers. The depleted uranium addition served to decrease the U-235 enrichment in the Tank 43H supernate so that the supernate could be evaporated with no risk of accumulating enriched uranium.
Date: October 15, 2002
Creator: Oji, L.N.
Partner: UNT Libraries Government Documents Department

CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

Description: Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. In this project a co-firing technology is proposed which would use manure that cannot be used for fertilizer, for power generation. Since the animal manure has economic uses as both a fertilizer and as a fuel, it is properly referred to as feedlot biomass (FB) for cow manure, or litter biomass (LB) for chicken manure. The biomass will be used a as a fuel by mixing it with coal in a 90:10 blend and firing it in existing coal fired combustion devices. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Therefore, it is the goal of the current research to develop an animal biomass cofiring technology. A cofiring technology is being developed by performing: (1) studies on fundamental fuel characteristics, (2) small scale boiler burner experiments, (3) gasifier experiments, (4) computer simulations, and (5) an economic analysis. The fundamental fuel studies reveal that biomass is not as high a quality fuel as coal. The biomass fuels are higher in ash, higher in moisture, higher in nitrogen and sulfur (which can cause air pollution), and lower in heat content than coal. Additionally, experiments indicate that the biomass fuels have higher gas content, release gases more readily than coal, and less homogeneous. Small-scale boiler experiments revealed that the biomass blends can be successfully fired, ...
Date: January 15, 2002
Creator: Annamalai, Kalyan; Sweeten, John; Mukhtar, Saqib; Thien, Ben; Wei, Gengsheng & Priyadarsan, Soyuz
Partner: UNT Libraries Government Documents Department

Integrated computer control system CORBA-based simulator FY98 LDRD project final summary report

Description: The CORBA-based Simulator was a Laboratory Directed Research and Development (LDRD) project that applied simulation techniques to explore critical questions about distributed control architecture. The simulator project used a three-prong approach comprised of a study of object-oriented distribution tools, computer network modeling, and simulation of key control system scenarios. This summary report highlights the findings of the team and provides the architectural context of the study. For the last several years LLNL has been developing the Integrated Computer Control System (ICCS), which is an abstract object-oriented software framework for constructing distributed systems. The framework is capable of implementing large event-driven control systems for mission-critical facilities such as the National Ignition Facility (NIF). Tools developed in this project were applied to the NIF example architecture in order to gain experience with a complex system and derive immediate benefits from this LDRD. The ICCS integrates data acquisition and control hardware with a supervisory system, and reduces the amount of new coding and testing necessary by providing prebuilt components that can be reused and extended to accommodate specific additional requirements. The framework integrates control point hardware with a supervisory system by providing the services needed for distributed control such as database persistence, system start-up and configuration, graphical user interface, status monitoring, event logging, scripting language, alert management, and access control. The design is interoperable among computers of different kinds and provides plug-in software connections by leveraging a common object request brokering architecture (CORBA) to transparently distribute software objects across the network of computers. Because object broker distribution applied to control systems is relatively new and its inherent performance is roughly threefold less than traditional point-to-point communications, CORBA presented a certain risk to designers. This LDRD thus evaluated CORBA to determine its performance and scaling properties and to optimize its use within the ICCS. ...
Date: January 15, 1999
Creator: Bryant, R M; Holloway, F W & Van Arsdall, P J
Partner: UNT Libraries Government Documents Department

Discovery of Disposal of Low-Level Waste in Slit Trench Segments Shallower than Analyzed in Performance Assessment

Description: The effect of disposing of low-level waste in slit trenches that are shallower than those analyzed in the revised performance assessment for the E-Area low-level waste facility is evaluated. The conclusion of the evaluation is that such disposal is bounded by the performance assessment if all of the disposed waste packages meet the slit trench Waste Acceptance Criteria and if at least four feet of soil is placed over the disposed waste packages.
Date: October 15, 2002
Creator: Cook, J.R.
Partner: UNT Libraries Government Documents Department

The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?

Description: In the search for better approaches to magnetic fusion it is important to keep in mind the lessons learned in the 50 years that fusion plasma confinement has been studied. One of the lessons learned is that ''closed'' and ''open'' fusion devices differ fundamentally with respect to an important property of their confinement, as follows: Without known exception closed systems such as the tokamak, the stellarator, or the reversed-field pinch, have been found to have their confinement times limited by non-classical, i.e., turbulence-related, processes, leading to the requirement that such systems must be scaled-up in dimensions to sizes much larger than would be the case in the absence of turbulence. By contrast, from the earliest days of fusion research, it has been demonstrated that open magnetic systems of the mirror variety can achieve confinement times close to that associated with classical, i.e., collisional, processes. While these good results have been obtained in both axially symmetric fields and in non-axisymmetric fields, the clearest cases have been those in which the confining fields are solenoidal and axially symmetric. These observations, i.e., of confinement not enhanced by turbulence, can be traced theoretically to such factors as the absence of parallel currents in the plasma, and to the constraints on particle drifts imposed by the adiabatic invariants governing particle confinement in axisymmetric open systems. In the past the MHD instability of axially symmetric open systems has been seen as a barrier to their use. However, theory predicts MHD-stable confinement is achievable if sufficient plasma is present in the ''good curvature'' regions outside the mirrors. This theory has been confirmed by experiments on the Gas Dynamic Trap mirror-based experiment at Novosibirsk, In this paper a new way of exploiting this stabilizing principle, involving creating a localized ''stabilizer plasma'' outside a mirror, will be discussed. To ...
Date: June 15, 2000
Creator: Post, R.F.
Partner: UNT Libraries Government Documents Department

The impact of thermal loading on repository performance at Yucca Mountain

Description: In the unsaturated zone at Yucca Mountain, liquid flow along preferential fracture pathways is the only credible mechanism capable of bringing water to waste packages and transporting radionuclide to the water table. Three categories of features or mechanisms will mitigate the impact of flow along preferential fracture pathways: (1) discontinuity in fracture pathways, (2) liquid-phase dispersion in fracture networks, and (3) fracture-matrix interaction. For repository areal power densities (APDs) that are too low to result in significant boiling or rock dry-out effects, the primary mode of fracture-matrix interaction is matrix imbibition. For high APDs, boiling and enhanced matrix imbibition due to rock dry-out significantly add to the capacity of the unsaturated zone to retard fracture-dominated flow. With the use of V-TOUGH code, hydrothermal flow calculations are made for a range of APDs and spent fuel ages. For APD > 20 kW/acre, repository-heat-generated flow of vapor and liquid in fractures is found to dominate the ambient hydrological system. For high APDs, boiling conditions can persist for 10,000 yr or longer and rock-dry benefits for at least 100,000 yr.
Date: January 15, 1992
Creator: Buscheck, T.A. & Nitao, J.J.
Partner: UNT Libraries Government Documents Department

Corrosion performance of structural alloys.

Description: Component reliability and long-term trouble-free performance of structural materials are essential in power-generating and gasification processes that utilize coal as a feedstock. During combustion and conversion of coal, the environments encompass a wide range of oxygen partial pressures, from excess-air conditions in conventional boilers to air-deficient conditions in 10W-NO{sub x} and gasification systems. Apart from the environmental aspects of the effluent from coal combustion and conversion, one concern from the systems standpoint is the aggressiveness of the gaseous/deposit environment toward structural components such as waterwall tubes, steam superheaters, syngas coolers, and hot-gas filters. The corrosion tests in the program described in this paper address the individual and combined effects of oxygen, sulfur, and chlorine on the corrosion response of several ASME-coded and noncoded structural alloys that were exposed to air-deficient and excess-air environments typical of coal-combustion and gasification processes. Data in this paper address the effects of preoxidation on the subsequent corrosion performance of structural materials such as 9Cr-1Mo ferritic steel, Type 347 austenitic stainless steel, Alloys 800, 825, 625, 214, Hastelloy X, and iron aluminide when exposed at 650 C to various mixed-gas environments with and without HCI. Results are presented for scaling kinetics, microstructural characteristics of corrosion products, detailed evaluations of near-surface regions of the exposed specimens, gains in our mechanistic understanding of the roles of S and Cl in the corrosion process, and the effect of preoxidation on subsequent corrosion.
Date: July 15, 1999
Creator: Natesan, K.
Partner: UNT Libraries Government Documents Department

Supersymmetric Higgs Boson Pair Production: Discovery Prospects at Hadron Colliders

Description: We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. We perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is re-emphasized. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously.
Date: September 15, 1999
Creator: Mizukoahi, Jose K.
Partner: UNT Libraries Government Documents Department

Concentration of uranium and plutonium in unsaturated spent fuel tests.

Description: Commercial spent fuel is being tested under oxidizing conditions at 90 C in drip tests with simulated groundwater to evaluate its long-term performance in a potential repository at Yucca Mountain [1-4]. The tests allow us to monitor the dissolution behavior of the spent fuel matrix and the release rates of individual radionuclides. This paper reports the U and Pu concentrations in the leachates of drip tests during 3.7 years of reaction. Changes in these concentrations are correlated with changes in the measured pH and the appearance of alteration products on the fuel surface. Although there is little thermodynamic information at 90 C for either uranyl or plutonium compounds, some data are available at 25 C [5-8]. The literature data for the U and Pu solubilities of U and Pu compounds were compared to the U and Pu concentrations in the leachates. We also compare Wilson's [9] U and Pu concentrations in semi-static tests at 85 C on spent fuel with our results.
Date: April 15, 1998
Creator: Finn, P. A.
Partner: UNT Libraries Government Documents Department

Krakow clean fossil fuels and energy efficiency program. Final report: Initial site investigation

Description: Original objective of this project was to retrofit the Balice Boilerhouse with a TCS Coal Micronization system and Amerex baghouses to achieve higher combustion efficiencies and lower air emission, including SO{sub 2}, NO{sub x}, CO and particulate matter. The Balice Boilerhouse is located adjacent to the Krakow Airport and provides heating steam for the Polish Military Unit No. 1616. In May 1995 the Polish Military announced it had decided to convert its boiler house to gas; thus cancelling the TCS Project. The balance of 1995 was spent considering alternative Project sites in Krakow for the application of the TCS coal Micronization technology.
Date: November 15, 1995
Partner: UNT Libraries Government Documents Department

Fissile Material Disposition Program: Deep Borehole Disposal Facility PEIS data input report for direct disposal. Direct disposal of plutonium metal/plutonium dioxide in compound metal canisters. Version 3.0

Description: The US Department of Energy (DOE) is examining options for disposing of excess weapons-usable nuclear materials [principally plutonium (Pu) and highly enriched uranium (HEU)] in a form or condition that is substantially and inherently more difficult to recover and reuse in weapons production. This report is the data input report for the Programmatic Environmental Impact Statement (PEIS). The PEIS examines the environmental, safety, and health impacts of implementing each disposition alternative on land use, facility operations, and site infrastructure; air quality and noise; water, geology, and soils; biotic, cultural, and paleontological resources; socioeconomics; human health; normal operations and facility accidents; waste management; and transportation. This data report is prepared to assist in estimating the environmental effects associated with the construction and operation of a Deep Borehole Disposal Facility, an alternative currently included in the PEIS. The facility projects under consideration are, not site specific. This report therefore concentrates on environmental, safety, and health impacts at a generic site appropriate for siting a Deep Borehole Disposal Facility.
Date: January 15, 1996
Creator: Wijesinghe, A.M. & Shaffer, R.J.
Partner: UNT Libraries Government Documents Department