The purpose of this analysis is to provide insight into the unsaturated-zone (UZ) subsystem performance through particle tracking analyses of the base-case flow fields. The particle tracking analyses will not be used directly in total-system performance-assessment (TSPA) calculations per se. The objective of this activity is to evaluate the transport of radionuclides through the unsaturated zone and to determine how different system parameters such as matrix diffusion, sorption, water-table rise, and perched water influence the transport to the water table. Plots will be generated to determine normalized cumulative breakthrough curves for selected radionuclides. The scope of this work is limited to the particle tracking analyses of ''base-case'' flow fields that are to be used by the code FEHM (Finite Element Heat and Mass; Zyvoloski 1997) for particle tracking simulations in ''Total System Performance Assessment-Site Recommendation Report'' (TSPA-SR).

This paper analyzes convergence properties of the Bayesian optimization algorithm (BOA). It settles the BOA into the framework of problem decomposition used frequently in order to model and understand the behavior of simple genetic algorithms. The growth of the population size and the number of generations until convergence with respect to the size of a problem is theoretically analyzed. The theoretical results are supported by a number of experiments.

This report consists of a chronology with internet access with budget FY 2000.

Proton-exchange membrane fuel cell (PEMFC) is one of the strongest contenders as a power source for space & electric vehicle applications. Platinum catalyst is used for both fuel and air electrodes in PEMFCs. CO contamination of H{sub 2} greatly affects electrocatalysts used at the anode of polymer electrolyte fuel cells and decrease the cell performance. Pt-Ru catalyst had been recognized to alleviate this problem by showing better tolerance to CO poisoning than only Pt catalyst. This irreversible poisoning of the anode can be happened even in concentrations as little as a few ppm, and therefore, require expensive scrubbing to reduce the contaminant concentration to acceptable level. In order to commercialize this environmentally sound source of energy/power system, development of suitable impurity tolerant catalyst is needed. This project will develop novel electrocatalysts for the PEMFCs and demonstrate the feasibility of a H{sub 2}/O{sub 2} fuel cell base on these materials. This project, if successful, will reduce the costs due to reduce Pt catalyst loading or use non-precious metals. It will increase the PEM fuel cell performance by increasing catalyst tolerance to methanol oxidation intermediate products (CO) and fuel impurities (H{sub 2}S), which will generate substantial interest for commercialization of the PEM …

Volumetric pulse heating of a thick-walled hollow sphere is numerically investigated. The primary objective is to validate a variety of LLNL 30 hydrocodes for modeling the dynamic behavior of fissile/fissionable metals subject to rapid ''fission-heating'' transients. The 30 codes tested include both DYNA3D and NIKE3D, as well as the ''ASCI'' code, ALE3D. The codes are compared ''head-to-head'' and are benchmarked against a 1D finite difference solution to the problem that is derived from basic principles. Three pulse-heating transients are examined with full-width-half-maximum pulse durations of 41{micro}s, 85{micro}s, and 140{micro}s, respectively. These three transients produce a significant range of dynamic responses in the thermo-elastic regime. We present results for dynamic radial displacements and stresses for each pulse, and also discuss which code features/options worked best for these types of calculations. In general, the code results are in excellent agreement for the simple system considered. Validation of code numerics in simple systems is a key first step toward future application of the codes in more complicated geometries (U).

The effect of line disorder induced by heavy ion irradiation and of point disorder induced by proton and electron irradiation on the upper and lower critical points in the vortex phase diagram of YBCO is presented. The authors find that dilute line disorder induces a Bose glass transition at low fields which is replaced at the lower critical point by first order melting at higher fields. Strong pinning point defects raise the lower critical point, while weak pinning point defects have little or no effect on the lower critical point. The upper critical point is lowered by point disorder, but raised by line disorder. First order melting is suppressed by point disorder in two ways, by lowering of the upper critical point only for weak point pins, or by merging of the upper and lower critical points for strong point pins. The differing responses of the upper and lower critical points to line and point disorder can be understood in a picture of transverse and longitudinal spatial fluctuations.

The femtosecond laser utilizes an unusually short laser pulse that results in little, if any, metallurgical damage in stainless steel and other materials. Studies of the process demonstrated high quality wall contours (metallurgically clean) when the laser was used to cut grooves in stainless steel discs. This study did prove the feasibility of the process as an alternate potential for the existing process for making burst discs. Significant additional work is required to increase groove reproducibility and produce three-dimensional cuts, requiring development of appropriate tooling and controllers.

Polytechnic University PhD student working on research projects in the area of fossil energy and renewable energy were supported in this program and did their research work at Brookhaven National Laboratory in the Department of Applied Sciences. One of these students had completed an MS degree in Chemical Engineering at Howard University while doing his research at Brookhaven. This student continued his studies by becoming a Polytechnic PhD student while doing his research work at Brookhaven.

Television image display using red, green, and blue solid state lasers is discussed.

Hydrogen atoms are ubiquitous species in radiolysis of many liquid and solid systems. They serve a very important role in passivation of solid-state defects in silica-based devices and there is concern about the role of radiolytic generation of molecular hydrogen in radioactive waste storage. The authors have made extensive studies of H atoms in water, ice and amorphous silica using conventional and time-resolved magnetic resonance. H atoms are exquisite probes of reaction dynamics and phase structure in these systems. Furthermore, via the study of Chemically Induced Dynamic Electron Polarization (CIDEP), additional insights into the mechanisms of radiolytic generation of H atoms and their fate can be obtained. With this considerable experience they embarked on the study of H atoms in zeolites and mesoporous solids to address the following questions: (1) What is the source of H atoms--bound hydroxyls or confined water? (2) Do the H atom dynamics in the water-saturated powders exhibit kinetics and spin relaxation that is similar to that in bulk silica, liquid water or ice? (3) What are the formation and destruction pathways of H atoms? This could be important for understanding radiolysis in silica-water systems, e.g., nuclear waste.

The last five years have witnessed a rapid increase in the volume of data on proton decaying nuclei. The path was led by decay studies with recoil mass separators equipped with double-sided Si strip detectors. The properties of many proton-decaying states were deduced, which triggered renewed theoretical interest in the process of proton decay. The decay experiments were closely followed by in-beam {gamma}-ray studies which extended one's knowledge of high-spin states of proton emitters. The unparalleled selectivity of the Recoil-Decay Tagging method combined with the high efficiency of large arrays of Ge detectors allowed, despite small cross sections and overwhelming background from strong reaction channels, the observation of excited states in several proton emitters. Recently, in-beam studies of the deformed proton emitters {sup 141}Ho and {sup 131}Eu have been performed with the GAMMASPHERE array of Ge detectors and the Fragment Mass Analyzer at ATLAS. Evidence was found for rotational bands in {sup 141}Ho and {sup 131}Eu. The deformations and the single-particle configurations proposed for the proton emitting states from the earlier proton-decay studies were confronted with the assignments deduced based on the in-beam data. It should be noted that the cross section for populating {sup 131}Eu is only about 50 …

The emphasis of this work was on investigating the mechanisms and factors that control the recovery of heavy oil, with the objective to improve recovery efficiencies. For this purpose, the interaction of flow, transport and reaction at various scales (from the pore-network to the field scales) were studied. Particular mechanisms investigated included the onset of gas flow in foamy oil production and in in-situ steam drive, gravity drainage in steam process, the development of sustained combustion fronts and the propagation of foams in porous media. Analytical, computational and experimental methods were utilized to advance the state of the art in heavy oil recovery. Successful completion of this research was expected to lead to improvements in the recovery efficiency of various heavy oil processes.

The authors consider the magnetic field dependence of the plasma resonance frequency in vortex crystal state. The authors found that low magnetic field induces a small correction to the plasma frequency proportional to the field. The slope of this linear field dependence is directly related to the average distance between the pancake vortices in the neighboring layers, wandering length. This length is determined by both Josephson and magnetic couplings between layers. At higher fields the Josephson coupling is suppressed collectively and is determined by elastic energy of the vortex lattice. Analyzing experimental data, they found that (1) the wandering length becomes comparable with the London penetration depth near {Tc}, (2) at small melting fields (< 20 G) the wandering length does not change much at the melting transition demonstrating existence of the line liquid phase in this field range, and (3) the self consistent theory of pancake fluctuations describes very well the field dependence of the Josephson plasma resonance frequency up to the melting point.

The assembly and packaging of MEMS (Microelectromechanical Systems) devices raise a number of issues over and above those normally associated with the assembly of standard microelectronic circuits. MEMS components include a variety of sensors, microengines, optical components, and other devices. They often have exposed mechanical structures which during assembly require particulate control, space in the package, non-contact handling procedures, low-stress die attach, precision die placement, unique process schedules, hermetic sealing in controlled environments (including vacuum), and other special constraints. These constraints force changes in the techniques used to separate die on a wafer, in the types of packages which can be used in the assembly processes and materials, and in the sealing environment and process. This paper discusses a number of these issues and provides information on approaches being taken or proposed to address them.

This report covers the work performed in the various physicochemical factors for the improvement of oil recovery efficiency. In this context the following general areas were studied: (1) The understanding of vapor-liquid flows in porous media, including processes in steam injection; (2) The effect of reservoir heterogeneity in a variety of foams, from pore scale to macroscopic scale; (3) The flow properties of additives for improvement of recovery efficiency, particularly foams and other non-Newtonian fluids; and (4) The development of optimization methods to maximize various measures of oil recovery.

While sulfur in diesel fuels helps reduce friction and prevents wear and galling in fuel pump and injector systems, it also creates environmental pollution in the form of hazardous particulates and SO{sub 2} emissions. The environmental concern is the driving force behind industry's efforts to come up with new alternative approaches to this problem. One such approach is to replace sulfur in diesel fuels with other chemicals that would maintain the antifriction and antiwear properties provided by sulfur in diesel fuels while at the same time reducing particulate emissions. A second alternative might be to surface-treat fuel injection parts (i.e., nitriding, carburizing, or coating the surfaces) to reduce or eliminate failures associated with the use of low-sulfur diesel fuels. This research explores the potential usefulness of a near-frictionless carbon (NFC) film developed at Argonne National Laboratory in alleviating the aforementioned problems. The lubricity of various diesel fuels (i.e., high-sulfur, 500 ppm; low sulfur, 140 ppm; ultra-clean, 3 ppm; and synthetic diesel or Fischer-Tropsch, zero sulfur) were tested by using both uncoated and NFC-coated 52100 steel specimens in a ball-on-three-disks and a high-frequency reciprocating wear-test rig. The test program was expanded to include some gasoline fuels as well (i.e., regular gasoline …

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the Nuclear Regulatory Commission's (NRC) shift to a risk-informed regulation, focusing on the: (1) views of NRC's staff on the quality of the work that NRC performs, the management of and staff's involvement in changes occurring in the agency, and the move to a risk-informed regulatory approach; and (2) status of NRC's efforts to develop a strategy to implement a risk-informed regulatory approach."

This report summarizes the AWT design, the testing and modeling completed on the design, the operating history of AWT turbines, and the additional work required to commercialize the design.

The question of how to proceed toward ever more realistic plasma simulation studies using ever increasing computing power is addressed. The answer presented here is the M3D (Multilevel 3D) project, which has developed a code package with a hierarchy of physics levels that resolve increasingly complete subsets of phase-spaces and are thus increasingly more realistic. The rationale for the multilevel physics models is given. Each physics level is described and examples of its application are given. The existing physics levels are fluid models (3D configuration space), namely magnetohydrodynamic (MHD) and two-fluids; and hybrid models, namely gyrokinetic-energetic-particle/MHD (5D energetic particle phase-space), gyrokinetic-particle-ion/fluid-electron (5D ion phase-space), and full-kinetic-particle-ion/fluid-electron level (6D ion phase-space). Resolving electron phase-space (5D or 6D) remains a future project. Phase-space-fluid models are not used in favor of delta f particle models. A practical and accurate nonlinear fluid closure for noncollisional plasmas seems not likely in the near future.

Using supercritical fluids as solvents is useful for both practical and theoretical reasons. It has been proposed to use supercritical CO{sub 2} as a solvent for synthesis because it eliminates the air pollution arising from other solvents. The properties of supercritical fluids can be easily varied with only modest changes in temperature and density, so they provide a way of testing theories of chemical reactions. It has also been proposed to use supercritical fluids for the treatment of hazardous mixed waste. For these reasons the authors have studied the production of radiolytic species in supercritical CO{sub 2} and have measured their reactivity as a function of density. They have shown that the C{sub 2}O{sub 4}{sup +} is formed. They also have shown that the electron transfer reactions of dimethylaniline to C{sub 2}O{sub 4}{sup +} and CO{sub 2}(e{sup {minus}}) to benzoquinone are diffusion controlled over a considerable density range.

A previous calculation of the renormalized dissipation in the nonconservatively forced one-dimensional Burgers equation, which encountered a catastrophic long-wavelength divergence approximately [k min]-3, is reconsidered. In the absence of velocity shear, analysis of the eddy-damped quasi-normal Markovian closure predicts only a benign logarithmic dependence on kmin. The original divergence is traced to an inconsistent resonance-broadening type of diffusive approximation, which fails in the present problem. Ballistic scaling of renormalized pulses is retained, but such scaling does not, by itself, imply a paradigm of self-organized criticality. An improved scaling formula for a model with velocity shear is also given.

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Astrophysics has traditionally been pursued at astronomical observatories and on theorists' computers. Observations record images from space, and theoretical models are developed to explain the observations. A component often missing has been the ability to test theories and models in an experimental setting where the initial and final states are well characterized. Intense lasers are now being used to recreate aspects of astrophysical phenomena in the laboratory, allowing the creation of experimental testbeds where theory and modeling can be quantitatively tested against data. We describe here several areas of astrophysics--supernovae, supernova remnants, gamma-ray bursts, and giant planets--where laser experiments are under development to test our understanding of these phenomena.

This paper presents calculations of the selection intensity of common selection and replacement methods used in genetic algorithms (GAs) with generation gaps. The selection intensity measures the increase of the average fitness of the population after selection, and it can be used to predict the average fitness of the population at each iteration as well as the number of steps until the population converges to a unique solution. In addition, the theory explains the fast convergence of some algorithms with small generation gaps. The accuracy of the calculations was verified experimentally with a simple test function. The results of this study facilitate comparisons between different algorithms, and provide a tool to adjust the selection pressure, which is indispensable to obtain robust algorithms.