fThe safe and verifiable disposition, either by incineration or chemical neutralization of chemical warfare (CW) agents requires correct {ital a priori} identification of each munition or container to be processed. A variety of NDE techniques have been used or tested for the examination and characterization of munitions. In the U.S., three widely used techniques are X-ray radiography, acoustic resonance spectroscopy (ARS), and prompt gamma ray neutron activation analysis (PINS). The technical bases, instrumental implementations, and applications of the U.S. versions of these methods are briefly discussed. 10 refs., 2 figs., 1 tab.

We consider unusual events in the CDF and D0 dilepton+jets sample with very high ET(lepton) and ET(missing). It is possible, but very unlikely, that these events originate from top quark pair production; however, they have characteristics that are better accounted for by decays of supersymmetric quarks with mass in the region of 300 GeV.

Neutron detectors are commonly used by the nuclear materials processing industry to monitor fissile materials in process vessels and tanks. The proper functioning of these neutron monitors must be periodically evaluated. We have developed and placed in routine use a PC-based multichannel analyzer (MCA) system for on-line BF3 and He-3 gas-filled detector function testing. The automated system: 1) acquires spectral data from the monitor system, 2) analyzes the spectrum to determine the detector`s functionality, 3) makes suggestions for maintenance or repair, as required, and 4) saves the spectrum and results to disk for review. The operator interface has been designed to be user-friendly and to minimize the training requirements of the user. The system may also be easily customized for various applications

A dc proton injector is being developed for a 6.7 MeV CW RFQ at Los Alamos. The RFQ input beam requirements are 75 keV energy, 110 mA dc proton current, and 0.20 {pi}mm-mrad rms normalized emittance. The injector has now produced a 75-keV, 117-mA dc proton beam (130 mA total current) with the required emittance. The emittance has been measured after a 2.1 m long two-solenoid beam transport system. The measured emittance can be explained in terms of the ion source emittance and beam transport through the focusing elements. Measured proton fractions are 90-92% of the beam current. Engineering of the accelerating column high-voltage design is being improved to increase the injector reliability. Injector design details and status are presented.

The search reaches for new gauge bosons at future hadron and lepton colliders are summarized for a variety of extended gauge models. Experiments at these energies will vastly improve over present limits and will easily discover a Z` and/or W` in the multi-TeV range.

The search reaches for both scalar(S) and vector(V) leptoquarks at future hadron colliders are summarized. In particular the authors evaluate the production cross sections of both leptoquark types at TeV33 and LHC as well as the proposed 60 and 200 TeV colliders through both quark-antiquark annihilation and gluon-gluon fusion: q{anti q},gg {r_arrow} SS,VV. Experiments at these machines should easily discover such particles if their masses are not in excess of the few TeV range.

Available experimental data on deformation and fracture behavior of polysynthetically twinned (PST) TiAl crystals are analyzed on the basis of the calculated results of bulk and defect properties and shear fault, cleavage and interfacial energies of TiAl and Ti{sub 3}Al. The extent of dissociation width of and ordinary dislocation is calculated to be larger at {alpha}{sub 2}/{gamma} and {gamma}/{gamma} interfaces by about two-fold as compared to the bulk of {gamma}-phase, suggesting the enhances slip along the interfaces when the crystal is a soft orientation. Propagation of (111) cleavage cracks is influenced by the mixed mode (II and III) of external loading applied to the coplanar deformation twinning and ordinary slip, leading to translamellar fracture. According to the calculated interfacial fracture energies, cleavage cracking si to occur on {alpha}{sub 2}/{gamma} boundaries and least likely on true-twin boundaries. Discussion is given on the roles of misfit dislocations, kinetics of dislocation-interface interactions and hydrogen embrittlement in deformation and fracture processes.

Article on the solubility of benzil in binary alkane + methyl tert-butyl ether solvent mixtures.

Article on the solubility of anthracene in binary alkane + methyl tert-butyl ether solvent mixtures at 298.15 K.

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The authors describe how they have parallelized Python, an interpreted object oriented scripting language, and used it to build an extensible message-passing C/C++ applications for the CM-5, Cray T3D, and Sun multiprocessor servers running MPI. Using a parallelized Python interpreter, it is possible to interact with large-scale parallel applications, rapidly prototype new features, and perform application specific debugging. It is even possible to write message passing programs in Python itself. The authors describe some of the tools they have developed to extend Python and applications of this approach.

We present a computational steering approach for controlling, analyzing, and visualizing very large scale molecular dynamics simulations involving tens to hundreds of millions of atoms. Our approach relies on extensible scripting languages and an easy to use tool for building extensions and modules. The system is extremely easy to modify, works with existing C code, is memory efficient, and can be used from inexpensive workstations and networks. We demonstrate how we have used this system to manipulate data from production MD simulations involving as many as 104 million atoms running on the CM-5 and Cray T3D. We also show how this approach can be used to build systems that integrate common scripting languages (including Tcl/Tk, Perl, and Python), simulation code, user extensions, and commercial data analysis packages.

Material that does not come out of a process as product or waste is called holdup. When this is fissile material, its location and quantity must be determined to improve safeguards and security as well as safety at the facility. The most common method for detecting and measuring holdup is with radiation based techniques. When using them, one must consider equipment geometry, geometry of holdup, and effects of background radiation when converting the radiation measurement into a fissile material quantity. We are developing complementary techniques that use tiny acoustic transducers, which are unaffected by background radiation, to improve holdup measurements by aiding in determining the above conversion factors for holdup measurements. Thus far, we have applied three techniques, Acoustic Interferometry, Pulse Echo, and bending Wave Propagation, of which the latter appears most effective. This paper will describe each of these techniques and show how they may ultimately reduce costs and personnel radiation exposure while increasing confidence I and accuracy of holdup measurements.

Latest results on jet production with rapidity gaps at the Fermilab Tevatron Collider are presented. Jet production via color-singlet exchange at high momenta transfer is observed as a class of events with low particle multiplicity (or rapidity gaps) between the two highest transverse energy jets. The particle multiplicity in various regions, and the dependencies on jet pseudorapidity separation and jet transverse energy are studied for these events. Results from two classes of dijet events with one or two forward rapidity gaps are also presented. The topology of these events is consistent with expectations for hard single diffraction and hard double pomeron exchange processes, respectively.

Classical molecular dynamics simulations are used to study damage produced during implantation of semiconductors with different ion masses and energies between 1-25 keV. The time scale for these simulations is only on the order of ns, and therefore problems like transient enhanced diffusion of dopants or formation of extended defects can not be studied with these models. Monte Carlo simulations, including as input the results obtained from molecular dynamics calculations, are used to extend the simulation time, and in particular, to study processes like ion implantation and defects diffusion in semiconductors. As an example, we show results for diffusion of the damage produced by implantation of Si with 5 keV Xe ions at low doses. Results of the simulations are compared with experiments in order to validate the model.

Procyon is a two-stage explosive pulsed-power system, consisting of a MK-IX helical generator and an explosively formed fuse (EFF) opening switch. A complete assembly including load and diagnostics is shown. The system was originally developed for the purpose of powering plasma z-pinch experiments and, in its original concept, was coupled to the plasma z-pinch load through a third pulsed power stage, a plasma flow switch (PFS). The authors have performed plasma z-pinch experiments both with and without a PFS, and they have now conducted the first heavy liner experiment. In this paper, they will summarize the results obtained to date with the system, and briefly discuss future applications.

Fermilab began operating a re-designed satellite refrigerator systems in November 1993. Upgrades were installed to operate the Tevatron at a magnet temperature of 3.5 K, approximately 1K lower than the original design. Refrigerator upgrades included new valve boxes, larger reciprocating expanders, the installation of cold vapor compressors, new sub-atmospheric instrumentation and an entirely new distributed controls system. Cryogenic system reliability data for Colliding Physics Run 1B is presented emphasizing a failure analysis for each aspect of the upgrade. Comparison to data for Colliding Physics Run 1A (previous to upgrade) is presented to show the impact of a major system overhaul. New operational problems and their solutions are presented in detail.

Cellulose, a polymer of glucose, is the principal component of biomass and, therefore, a major source of waste that is either buried or burned. Examples of biomass waste include agricultural crop residues, forestry products, and municipal wastes. Recycling of this waste is important for energy conservation as well as waste minimization and there is some probability that in the future biomass could become a major energy source and replace fossil fuels that are currently used for fuels and chemicals production. It has been estimated that in the United States, between 100-450 million dry tons of agricultural waste are produced annually, approximately 6 million dry tons of animal waste, and of the 190 million tons of municipal solid waste (MSW) generated annually, approximately two-thirds is cellulosic in nature and over one-third is paper waste. Interestingly, more than 70% of MSW is landfilled or burned, however landfill space is becoming increasingly scarce. On a smaller scale, important cellulosic products such as cellulose acetate also present waste problems; an estimated 43 thousand tons of cellulose ester waste are generated annually in the United States. Biocatalysts could be used in cellulose waste minimization and this chapter describes their characteristics and potential in bioconversion and …

The author discusses the mass parameters appearing in the gauge theory of the strong interactions, concentrating on the two flavor case. He shows how the effect of the CP violating parameter {theta} is simply interpreted in terms of the state of the aether via an effective potential for meson fields. For degenerate flavors he shows that a first order phase transition is expected at {theta} = {pi}. The author speculates on the implications of this structure for Wilson`s lattice fermions.

The objective of this project is to develop systems to reduce the cost of treating subquality natural gas. Based on over 1,000 laboratory experiments on vapor-liquid equilibria and mass transfer and simulation studies, the use of N-Formyl Morpholine as a solvent together with structured packings has the following advantages: high capacity for H{sub 2}S and CO{sub 2} removal; little or no refrigeration required; less loss of hydrocarbons (CH{sub 4}, C{sub 2}-C{sub 6}); and dehydration potential. To verify these findings and to obtain additional data base for scale-up, a field test unit capable of processing 1MMSCF/d of natural gas has been installed at the Shell Western E and P Inc. (SWEPI) Fandango processing plant site. The results of the testing at the Fandango site will be presented when available.

Six US Department of Energy Laboratories are carrying out a program of cooperation with the Russian Research Center Kurchatov Institute to improve nuclear material protection, control and accounting (MPC and A) at the Institute. In 1995 the primary emphasis of this program was the implementation of improved physical protection at a demonstration building at Kurchatov, and the upgrading the computerized materials accounting system, measurement instrumentation, and physical inventory procedures for a critical assembly within this building. Work continues in 1996 at this building but now also have begun at the two Kurchatov buildings which constitute the Central Storage Facility. At this facility, there will be upgrades in the physical inventory taking procedures, a test and evaluation of gamma-ray isotopic measurements, and evaluations of nuclear material portal monitors and neutron-based measurement equipment. There will also be implementation of an improved computerized materials accounting system which will include bar code printing and reading equipment, development of a tamper indicating device program, and substantial improvements in physical protection. Finally, vulnerability assessments begun in 1995 are being extended to additional high priority facilities at Kurchatov.

A comprehensive climate system model is under development at Lawrence Livermore National Laboratory. The basis for this model is a consistent coupling of multiple complex subsystem models, each describing a major component of the Earth`s climate. Among these are general circulation models of the atmosphere and ocean, a dynamic and thermodynamic sea ice model, and models of the chemical processes occurring in the air, sea water, and near-surface land. The computational resources necessary to carry out simulations at adequate spatial resolutions for durations of climatic time scales exceed those currently available. Distributed memory massively parallel processing (MPP) computers promise to affordably scale to the computational rates required by directing large numbers of relatively inexpensive processors onto a single problem. We have developed a suite of routines designed to exploit current generation MPP architectures via domain and functional decomposition strategies. These message passing techniques have been implemented in each of the component models and in their coupling interfaces. Production runs of the atmospheric and oceanic components performed on the National Environmental Supercomputing Center (NESC) Cray T3D are described.

A new algorithm that uses a multiparticle PARMILA-based code to match high peak current H{sup +} beam ({approx}21 mA) into the Los Alamos Neutron Science Center (LANSCE) drift tube linac (DTL) has been developed. Two single cell rf bunchers in the low energy beam transport (LEBT) prepare the initially unbunched beam for DTL capture. The transverse distribution at the entrance to the DTL is set with four quadrupoles in the 1.26 m between the last transverse emittance measuring station and the DTL entrance. Previous matching algorithms used TRACE and TRACE 3-D to determine these quadrupole strengths. PARMILA simulation show this procedure produces non-zero mismatch and additional emittance growth through the DTL for high current beams. Because of strong space-charge forces and a rapidly forming longitudinal bunch, simple envelope calculations do not model the beam evolution in the LEBT well. A PARMILA model of this region was combined with ant iterative search routine to set the LEBT quadrupole strengths to achieve a better transverse match into the DTL. Simulations predict a significant reduction in transverse emittance at the exit of the DTL over the typical TRACE 3-D result.

The improved work control system at the Idaho Chemical Processing Plant minimizes review and approval time, maximizes field work time, and maintains full compliance with applicable requirements. The core team method gives ownership and accountability to knowledgeable individuals, and the teams use sophisticated scheduling techniques to improve information sharing and cost control and to establish accurate roll-up master schedules.