Novel 3+1 dimensional N = 2 superconformal field theories (with tensionless BPS string solitons) are believed to arise when two sets of M5 branes intersect over a 3+1 dimensional hyperplane. We derive a DLCQ description of these theories as supersymmetric quantum mechanics on the Higgs branch of suitable 4d N = 1 supersymmetric gauge theories. Our formulation allows us to determine the scaling dimensions of certain chiral primary operators in the conformal field theories. We also discuss general criteria for quantum mechanical DLCQ descriptions of supersymmetric field theories (and the resulting multiplicities and scaling dimensions of chiral primary operators).

Advances in the processing and fabrication of Ag-sheathed (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) high-T{sub c} superconductors by the powder-in-tube technique continue to bring this material closer to commercial applications. Enhancement of the transport critical current density (J{sub c}) of Ag-sheathed Bi-2223 tapes was achieved by increasing the packing density of the precursor powder, improving mechanical deformation, and adjusting the cooling rate. Long lengths (>150 m) of multifilamentary Bi-2223 tapes have been fabricated and carry critical currents (I{sub c}) of >50 A (J{sub c} {approx} 25 kA/cm{sup 2}) at 77 K in self-field. A 1260-m-long tape carried an I{sub c} of 18 A (J{sub c} {approx} 12 kA/cm{sup 2}) from end-to-end. Several prototype coils have been assembled from these long-length tapes. Recent progress in the fabrication of Bi-2223 tapes is presented in this paper.

The conclusions of this report are that molybdenum can effectively be separated from uranium and plutonium using TRU-Resin; and that separation of the {sup 99}Mo from the actinides will reduce the analyst's exposure and simplify analysis for the actinide elements.

Many irradiation effects in Fe-Cr-Ni alloys such as radiation-induced segregation, radiation-enhanced diffusion, and void swelling are known to vary with bulk alloy composition. The development of microstructural and microchemical changes during irradiation and during post-irradiation annealing is determined by the rate of diffusion of point defects and alloying elements. To accurately predict the changes in grain boundary chemistry due to radiation-induced segregation and post-irradiation annealing, the composition dependence of diffusion parameters, such as the migration energy, must be known. A model has been developed which calculates migration diffusivity. The advantages of this calculational method are that a single set of input parameters can be used for a wide range of bulk alloy compositions, and the effects of local order can easily be incorporated into the calculations. A description of the model is presented, and model calculations are compared to segregation measurements from seven different iron-chromium-nickel alloys, irradiated with protons to doses from 0.1 to 3.0 dpa at temperatures between 200 C and 600 C. Results show that segregation trends can be modeled using a single set of input parameters with the difference between model calculation and measurement being less than 5 at%, but usually less than 2 at%. Additionally, model …

Following earlier investigations on the dissociation rates of halogen containing molecules, we studied the thermal decompositions of CHCl{sub 3} and CF{sub 3}Br. In addition, we measured the branching ratio and rate constants for the thermal decomposition of H{sub 2}CO. We studied three bimolecular rate processes: H + H{sub 2}CC0, CF{sub 3} + H{sub 2}, and H + CF{sub 3}H. Decomposition studies in reflected shock waves on three reactions were completed using atomic resonance absorption spectroscopic (ARAS) detection and/or the laser schlieren density gradient (LS) method.

In 1996, Argonne National Laboratory (ANL) conducted a preliminary technical and legal evaluation of disposing of nonhazardous oil-field wastes (NOW) into salt caverns. Argonne determined that if caverns are sited and designed well, operated carefully, closed properly, and monitored routinely, they could be suitable for disposing of oil-field wastes. On the basis of these findings, Argonne subsequently conducted a preliminary evaluation of the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from the NOW disposed of in domal salt caverns. Steps used in this evaluation included the following: identifying potential contaminants of concern, determining how humans could be exposed to these contaminants, assessing contaminant toxicities, estimating contaminant intakes, and calculating human cancer and noncancer risk estimates. Five postclosure cavern release scenarios were assessed. These were inadvertent cavern intrusion, failure of the cavern seal, failure of the cavern through cracks, failure of the cavern through leaky interbeds, and a partial collapse of the cavern roof. Assuming a single, generic, salt cavern and generic oil-field wastes, potential human health effects associated with constituent hazardous substances (arsenic, benzene, cadmium, and chromium) were assessed under each of these scenarios. Preliminary results provided excess cancer risk and …

High voltage TEMs were introduced commercially thirty years ago, with the installations of 500 kV Hitachi instruments at the Universities of Nagoya and Tokyo. Since that time 53 commercial instruments, having maximum accelerating potentials of 0.5-3.5 MV, will have been delivered by the end of 1998. Table 1 summarizes the sites and some information regarding those HVEMS which are available in 1998. This corrects, updates and expands an earlier report of this sort [2]. There have been three commercial HVEM manufacturers: AEI (UK), Hitachi and JEOL (Japan). The proportion of the total number of HVEMS produced by each manufacturer is similar to that reflected in Table 1: AEI and Kratos/AEI (12), Hitachi (20) and JEOL (21). The term Kratos/AEI refers to instruments delivered after the takeover of AEI by Grates in the late 1970's. In Table 1 only maximum accelerating potentials are listed, which is generally also the design value for which the resolution for imaging was optimized. It is important to realize that in many applications, especially those studying irradiation effects, much lower voltages may be employed somewhat routinely to minimize atom displacements by the incident electron beam during analysis. These minimum values range from 100 kV for the …

This paper describes the application of an electrical network characterization method to an optimization model that is designed to simulate subarea-level energy transactions. The network characterization method determines subarea clusters of system buses that electrically respond to perturbations in a very similar manner. The method produces a reduced number of transmission constraints and preserves parallel path representations. The least-cost, linear programming (LP) formulation takes advantage of data reduction techniques to simplify model transmission constraints, while supporting parallel path system characteristics and energy tagging of subarea transactions. An overview of the proposed method describes the problem domain and key model features. The paper then presents two model applications that illustrate generator siting and line overload screening analyses.

The magnitudes of both void swelling and radiation-induced segregation (RIS) in iron-chromium-nickel alloys are dependent on bulk alloy composition. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation. This local composition change reduces the subsequent vacancy flux to the void, thereby reducing void swelling. In this work, the resistance to swelling from major element segregation is estimated using diffusivities derived from grain boundary segregation measurements in irradiated iron-chromium-nickel alloys. The resistance to void swelling in iron- and nickel-base alloys correlates with the segregation and both are functions of bulk alloy composition. Alloys that display the greatest amount of nickel enrichment and chromium depletion are found to be most resistant to void swelling, as predicted. Additionally, swelling is shown to be greater in alloys in which the RIS profiles are slow to develop.

The purpose of this report is to describe the thermal hydraulic computer models, the computer model benchmarking and methodology to be used in performing the analysis necessary for the resolution of the high heat safety issue for Tank 241-C, -106.

This document establishes performance requirements for the double-shell tank system. These requirements, in turn, will be incorporated in the System Specification for the Double-Shell Tank System (Grenard and Claghorn 1998). This version of the document establishes requirements that are applicable to the first phase (Phase 1) of the Tank Waste Remediation System (TWRS) mission described in the TWRS Mission Analysis Report (Acree 1998). It does not specify requirements for either the Phase 2 mission or the double-shell tank system closure period.

In July 1993, the Defense Nuclear Facilities Safety Board (DNFSB) transmitted Recommendation 93-5 (Conway 1993) to the US Department of Energy (DOE). Recommendation 93-5 noted that there was insufficient tank waste technical information and the pace to obtain it was too slow to ensure that Hanford Site wastes could be safely stored, that associated operations could be conducted safely, and that future disposal data requirements could be met. In May 1996, the DOE issued Revision 1 of the Recommendation 93-5 Implementation Plan (DOE-RL 1996). The Implementation Plan revision presented a modified approach to achieve the original plan`s objectives. The approach concentrated on actions necessary to ensure that wastes can be safely stored, that operations can be safely conducted, and that timely characterization information for the tank waste Disposal Program could be obtained. The Implementation Plan proposed 28 High Priority tanks, which, if sampled and analyzed, were expected to provide information to answer questions regarding safety and disposal issues. The High Priority tank list was originally developed in Section 9.0 of the Tank Waste Characterization Basis (Brown et al. 1995) by integrating the needs of the various safety and disposal programs. The High Priority tank list represents a set of tanks …

This report evaluates the design of the replacement cross-site transfer system structures, systems, and components for safety related applications as defined in the Tank Waste Remediation Systems Basis for Interim Operations.

Based on previous results [1] further details of the oxidation of copper foil 2 Cu + O{sub 2} {r_arrow} 2 CuO were resolved using high quality, high temperature Cu{sub 2}O and CuO standards for Cu-K XAFS and Cu-K PCA [2] analysis. These were prepared from copper foils using the same experimental techniques as for the oxidation under study. As the reaction can be divided into a step-wise oxidation mechanism: 2 Cu + 0.5 O{sub 2} {r_arrow}Cu{sub 2}O; Cu{sub 2}O + 0.5 O{sub 2} {r_arrow} 2 CuO, we attempted to check whether the formation of CuO is kinetically inhibited (delayed) or whether it takes place simultaneously to the formation of Cu{sub 2}O. To achieve an optimal time resolution the QEXAFS technique [3] was applied. This investigation was completed by XRD and SEM investigations on samples quenched within the oxidation period.

The motion of water adsorbed in Type-Azeotites has been measured using quasielastic and inelastic neutron spectroscopy. Changes in the charge-compensating cation has a dramatic effect on the low frequency vibrational spectrum, which has a well defined low frequency feature for sodium and lithium but no such peak is present for the case of potassium and calcium. At 297K the low frequency feature is still visible, while there is also quasielastic broadening of the elastic line due to diffusion of the water protons. These measurements are interpreted in the light of the results from computer simulations of these materials.