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Inclusion formation and microstructure development in self-shielded flux cored arc welds has been investigated before [1,2]. Results showed that the liquid metal reactions could promote either Al{sub 2}O{sub 3} or AlN formation depending upon the aluminum concentration in the weld metal. The residual aluminum that remained in solution was found to modify the solidification behavior of liquid to {delta}-ferrite and subsequent transformation of {delta}-ferrite to austenite during weld cooling. In this work, the microstructure evolution in the heat-affected-zone (HAZ) of self-shielded flux cored arc weld (FCAW-S) overlays were investigated using in-situ Time-Resolved X-ray Diffraction (TRXRD) with a high flux Synchrotron radiation beam [3, 4].

Experimental studies involving equilibrium solubility and dissolution/precipitation rates were initiated on aluminum hydroxide phases prevalent under geothermal reservoir conditions. A large capacity, hydrogen-electrode concentration cell (HECC) was constructed specifically for this purpose.

With the Jefferson Lab 12 GeV (11 GeV for Halls A, B and C) upgrade, several new physics windows open up. In particular, a large kinematics domain in deep inelastic scattering becomes available. Coupled to the high luminosity and high polarization of beam and targets, Jefferson Lab will be in a unique position to make a significant contribution in the understanding of nucleon and nuclear structure, and strong interaction in the high x region. (For a non-expert, roughly speaking x is the percentage of momentum carried by the leading quark with which the electron is directly interacting). Theoretically, the high x region is relatively clean, where it provides a testing ground for the understanding of the nucleon structure in terms of a simple quark picture. Due to the fact that the quark distribution drops fast when x becomes large, few precision data exists in this region (especially for the spin-dependent nucleon structure). Precision data in this region (at relatively low Q{sup 2}) are not only important for understanding the structure there, but also have a significant impact for a search of new physics beyond the standard model at very high energies. A high luminosity is crucial for getting precise information …

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We have measured proton reaction cross sections over a wide mass and energy range at the Brookhaven AGS accelerator. The samples were elemental Be, C, Al, Cu, W, and Pb; the measurements were carried out at ten incident proton kinetic energies in the range 0.54 to 7.8 GeV. The experiment was similar to an earlier experiment in the 200-550 MeV range by Renberg et al. The new results are in good agreement with those of Renberg et al. at the overlap point near 550 MeV. The combined results of the two experiments show an energy dependence expected from the behavior of the nucleon-nucleon cross sections. The results are reproduced by calculations based on variants of the impulse approximation and Glauber theory.

Energy production, deformation, and fluid transport in reservoirs are linked closely. Recent field, laboratory, and theoretical studies suggest that, under certain stress conditions, compaction of porous rocks may be accommodated by narrow zones of localized compressive deformation oriented perpendicular to the maximum compressive stress. Triaxial compression experiments were performed on Castlegate, an analogue reservoir sandstone, that included acoustic emission detection and location. Initially, acoustic emissions were focused in horizontal bands that initiated at the sample ends (perpendicular to the maximum compressive stress), but with continued loading progressed axially towards the center. This paper describes microscopy studies that were performed to elucidate the micromechanics of compaction during the experiments. The microscopy revealed that compaction of this weakly-cemented sandstone proceeded in two phases: an initial stage of porosity decrease accomplished by breakage of grain contacts and grain rotation, and a second stage of further reduction accommodated by intense grain breakage and rotation.

Wavefront reconstruction techniques using the least-squares estimators are computationally quite expensive. We compare wavelet and Fourier transforms techniques in addressing the computation issues of wavefront reconstruction in adaptive optics. It is shown that because the Fourier approach is not simply a numerical approximation technique unlike the wavelet method, the Fourier approach might have advantages in terms of numerical accuracy. However, strictly from a numerical computations viewpoint, the wavelet approximation method might have advantage in terms of speed. To optimize the wavelet method, a statistical study might be necessary to use the best basis functions or ''approximation tree.''

The Savannah River Technology Center (SRTC) designed and fabricated tritium target/blanket assemblies which were irradiated for six months at the Los Alamos Neutron Science Center (LANSCE). Cooling water was supplied to the assemblies through 1 inch diameter 304L Stainless Steel (SS) tubing. To attach the 304L SS tubing to the modules a 304L SS to 6061-T6 Aluminum (Al) inertia welded transition joint was used. These SS/Al inertia weld transition joints simulate expected transition joints in the Accelerator Production of Tritium (APT) Target/Blanket where as many as a thousand SS/Al weld transition joints will be used. Materials compatibility between the 304L SS and the 6061-T6 Al in the spallation neutron environment is a major concern as well as the corrosion associated with the cooling water flowing through the piping. The irradiated inertia weld examination will be discussed.

Assessment of the long-term performance of nuclear melt glass under saturated conditions provides insight into factors controlling radionuclide release into groundwater. Melt glass samples were collected from an underground nuclear detonation cavity at the Nevada Test Site that was in contact with groundwater for more than 10 years. The samples were made into thin sections and the distribution of alpha activity mapped using CR-39 plastic detectors. The melt glass is visually heterogeneous and the results of the alpha track radiography indicate that the highest alpha activity is associated with areas of dark colored glass. Analyses of the thin sections by alpha spectrometry show the prominent actinide species to be {sup 238}Pu, {sup 239}Pu and {sup 241}Am. Scanning electron microprobe analysis of the bulk glass shows conspicuous alteration layers lining internal vesicle surfaces in the glass. X-ray diffraction patterns for the alteration phases are consistent with clay mineral compositions. Glass dissolution models indicate these layers are too thick to have formed at ambient temperatures over the 10 year period in which they remained in a saturated environment. This implies the alteration layers likely formed at temperatures higher than ambient during cooling of the cavity following the underground detonation. Mobilization of this …

Raman and infrared spectra of several organic superconductors are presented, showing some unusual behaviors of a sharp line at 890 cm{sup {minus}} in both spectra. These include a frequency shift below T{sub c}, a positive deuterium isotope shift, frequency softening at low temperatures and sensitivity to lattice superstructure. It is proposed that either the ion or the neutral molecule has a distortion with a strong v{sub 60}(B{sub 3g}) mode component.

The preheating of laser-heated microballoon targets has been measured by time-resolved x-ray and extreme ultraviolet (euv) spectroscopy on the 30 kJ, 351 nm, 60-beam laser-fusion system at the University of Rochester Laboratory for Laser Energetics. Thin coatings of aluminum overcoated with magnesium served as indicators. both the sequence of the x-ray line emission and the intensity of euv radiation were used to determine a preheating peaking at {approx} 10 ns prior to onset of the main laser pulse, with a power density {approx_equal}1% of the main pulse. The measurements are supported by numerical modeling. Further information is provided by absorption spectra from the aluminum coating, backlighted by continuum from the heated surface. The exact source of the preheating energy remains unknown at present, but most likely arrives from early laser leakage through the system. The present target diagnostic is particularly useful when all beams cannot be monitored directly at all laser wavelengths.

A ceramic waste form composed of glass-bonded sodalite is being developed at Argonne National Laboratory (ANL) for immobilization and disposition of the molten salt waste stream from the electrometallurgical treatment process for metallic DOE spent nuclear fuel. As part of the spent fuel treatment program at ANL, a model is being developed to predict the long-term release of radionuclides under repository conditions. Dissolution tests using dilute, pH-buffered solutions have been conducted at 40, 70, and 90 C to determine the temperature and pH dependence of the dissolution rate. Parameter values measured in these tests have been incorporated into the model, and preliminary repository performance assessment modeling has been completed. Results indicate that the ceramic waste form should be acceptable in a repository environment.

We demonstrate that the X-ray standing wave (XSW) technique is a powerful probe of the electrical double-layer (EDL) structure. Measurements were made of Sr adsorption at the rutile (110)-water interface from aqueous solutions. Our results show that Bragg XSW, using small-period standing waves generated by Bragg diffraction from the substrate, precisely probes the location of ions within the condensed layer, and the in situ partitioning of ions between the condensed and diffuse layers. Such measurements can provide important constraints for the development and verification of theoretical models that describe ion adsorption at the solid-water interface.

In the current study, the generality of the key underpinnings of the Stochastic Finite Element (SFEM) method is exploited in a nonlinear shock and vibration application where parametric uncertainty enters through random variables with probabilistic descriptions assumed to be known. The system output is represented as a vector containing Shock Response Spectrum (SRS) data at a predetermined number of frequency points. In contrast to many reliability-based methods, the goal of the current approach is to provide a means to address more general (vector) output entities, to provide this output as a random process, and to assess characteristics of the response which allow one to avoid issues of statistical dependence among its vector components.

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Instrumentation concepts for the Very Large Hadron Collider (VLHC) are discussed. Different design concepts for the VLHC result in substantially different instrumentation layouts. High field, cold bore magnets have instrumentation requirements very similar to the SSC and LHC. In contrast, the low field warm bore transmission line magnets have very sparse instrumentation and the long magnet length allows the cable plant to be preinstalled on the magnets. Specialized beam instrumentation concepts including permanently sealed semi-rigid coax BLM's and distributed coupled-bunch damping systems are discussed.

We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented.

The motivation, prospects, and R and D plans for future high-intensity muon facilities are described, with an emphasis on neutrino factories. The additional R and D needed for muon colliders is also considered.

Experiments are presented in which electrical-impedance tomography (EIT) and gamma-densitometry tomography (GDT) measurements were combined to simultaneously measure the solid, liquid, and gas radial distributions in a vertical three-phase flow. The experimental testbed was a 19.05-cm diameter bubble column in which gas is injected at the bottom and exits out the top while the liquid and solid phases recirculate. The gas phase was air and the liquid phase was deionized water with added electrolytes. Four different particle classes were investigated for the solid phase: 40--100 {micro}m and 120--200 {micro}m glass beads (2.41 g/cm{sup 3}), and 170--260 {micro}m and 200--700 {micro}m polystyrene beads (1.04 g/cm{sup 3}). Superficial gas velocities of 3 to 30 cm/s and solid volume fractions up to 0.30 were examined. For all experimental conditions investigated, the gas distribution showed only a weak dependence on both particle size and density. Average gas volume fraction as a function of superficial gas velocity can be described to within {+-} 0.04 by curve passing through the center of the data. For most cases the solid particle appeared to be radically uniformly dispersed in the liquid.

The authors develop and evaluate a modified invasion percolation (MIP) model for quasi-static immiscible displacement in horizontal fractures. The effects of contact angle, local aperture field geometry, and local in-plane interracial curvature between phases are included in the calculation of invasion pressure for individual sites in a discretized aperture field. This pressure controls the choice of which site is invaded during the displacement process and hence the growth of phase saturation structure within the fracture. To focus on the influence of local in-plane curvature on phase invasion structure, they formulate a simplified nondimensional pressure equation containing a dimensionless curvature number (C) that weighs the relative importance of in-plane curvature and aperture-induced curvature. Through systematic variation of C, they find in-plane interracial curvature to greatly affect the phase invasion structure. As C is increased from zero, phase invasion fronts transition from highly complicated (IP results) to microscopically smooth. In addition, measurements of fracture phase saturations and entrapped cluster statistics (number, maximum size, structural complication) show differential response between wetting and nonwetting invasion with respect to C that is independent of contact angle hysteresis. Comparison to experimental data available at this time substantiates predicted behavior.

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Both the developed and developing nations of the world would like to move toward a position of sustainable development while paying attention to the restoration of natural resources, improving the environment, and improving the quality of life. The impacts of geothermal development projects are generally positive. It is important, however, that the environmental issues associated with development be addressed in a systematic fashion. Drafted early in the project planning stage, a well-prepared Environmental Impact Assessment (EIA) can significantly add to the quality of the overall project. An EIA customarily ends with the decision to proceed with the project. The environmental analysis process could be more effective if regular monitoring, detailed in the EIA, continues during project implementation. Geothermal development EIAs should be analytic rather than encyclopedic, emphasizing the impacts most closely associated with energy sector development. Air quality, water resources and quality, geologic factors, and socioeconomic issues will invariably be the most important factors. The purpose of an EIA should not be to generate paperwork, but to enable superb response. The EIA should be intended to help public officials make decisions that are based on an understanding of environmental consequences and take proper actions. The EIA process has been defined …