Recent data on low-mass X-ray binaries (LMXBs) and millisecond pulsars (MSPs) pose a challenge to evolutionary theories which neglect the effects of disk and comparison irradiation. Here we discuss the main features of a radiation-driven (RD) evolutionary model that may be applicable to several LMXBs. According to this model, radiation from the accreting compact star in LMXBs vaporizes'' the accretion disk and the companion star by driving a self-sustained mass loss until a sudden accretion-turn off occurs. The main characteristics of the RD-evolution are: (1) lifetime of RD-LMXB's is of order 10{sup 7} years or less; (2) both the orbital period gap and the X-ray luminosity may be consequences of RD-evolution of LMXB's containing lower main sequence and degeneration companion stars; (3) the companion star may transfer mass to the primary even if it underfills its Roche lobe; (4) a class of recycled MSPs can continue to vaporize the low-mass companions by a strong pulsar wind even after the accretion turn-off; (5) the RD-evolutionary model resolves the apparent statistical descrepancy between the number of MSPs and their LMXB progenitors in the Galaxy. We discuss the implications of the discovery of single MSPs in low-density globular clusters and the recent measurements …

In processing radioactive material there are certain steps which have customarily required operators working at glove box enclosures. This can subject the operators to low level radiation dosages and the risk of accidental contamination, as well as generate significant radioactive waste to accommodate the human interaction. An automated system is being developed to replace the operator at the glove box and thus remove the human from these risks, and minimize waste. Although most of the processing can be automated with very little human operator interaction, there are some tasks where intelligent intervention is necessary to adapt to unexpected circumstances and events. These activities will require that the operator be able to interact with the process using a remote manipulator in a manner as natural as if the operator were actually in the work cell. This robot-based remote manipulation system, or telerobot, must provide the operator with an effective means of controlling the robot arm, gripper and tools. This paper describes the effort in progress in Lawrence Livermore National Laboratory to achieve this capability. 8 refs.

A copy of a newspaper article pertaining to Califonia's Proposition 186 and the reaction of the gay and lesbian community.

Radioactive wastes are generated at many DOE laboratories, military facilities, fuel fabrication and enrichment plants, reactors, hospitals, and university research facilities. At all of these sites, wastes must be separated, packaged, categorized, and packed into some sort of container--usually 208-L (55-gal) drums--for shipment to waste-storage sites. Prior to shipment, the containers must be labeled, assayed, and certified; the assay value determines the ultimate disposition of the waste containers. An accurate nondestructive assay (NDA) method would identify all the radioisotopes present and provide a quantitative measurement of their activity in the drum. In this way, waste containers could be routed in the most cost-effective manner and without having to reopen them. Currently, the most common gamma-ray method used to assay nuclear waste drums is segmented gamma-ray scanning (SGS) spectrometer that crudely measures only the amount of {sup 235}U or {sup 239}Pu present in the drum. This method uses a spatially-averaged, integrated, emitted gamma-ray-intensity value. The emitted intensity value is corrected by an assumed constant-attenuation value determined by a spatially-averaged, transmission (or active) measurement. Unfortunately, this typically results in an inaccurate determination of the radioactive activities within a waste drum because this measurement technique is valid only for homogeneous-attenuation or known drum …

The paper contains over eighty rules for editing graphs, arranged under nine major headings in a logical sequence for editing all the graphs in a manuscript. It is excerpted from a monograph used at the Lawrence Livermore National Laboratory to train beginning technical editors in editing graphs; a corresponding Hypercard stack is also used in this training. 6 refs., 4 figs.

Using Lanczos exact diagonalization, we investigate the effects of the competition between the electro-electron and electron-phonon interactions in the context of the 1-D tight-binding Peierls-Hubbard Hamiltonian, studying various structural, optical, and vibrational properties of strongly correlated systems. We use polyacetylene as our experimental guide, and perform a parameter space search to determine the level at which a unique set of parameters can model this prototypical conducting polymer and, more generally, the applicability of the simple'' 1-D Peierls-Hubbard Hamiltonian to these highly interesting materials. 9 refs., 3 tabs.

We describe WARP, a new particle-in-cell code being developed and optimized for ion beam studies in true geometry. We seek to model transport around bends, axial compression with strong focusing, multiple beamlet interaction, and other inherently 3d processes that affect emittance growth. Constraints imposed by memory and running time are severe. Thus, we employ only two 3d field arrays ({rho} and {phi}), and difference {phi} directly on each particle to get E, rather than interpolating E from three meshes; use of a single 3d array is feasible. A new method for PIC simulation of bent beams follows the beam particles in a family of rotated laboratory frames, thus straightening'' the bends. We are also incorporating an envelope calculation, an (r, z) model, and 1d (axial) model within WARP. The BASIS development and run-time system is used, providing a powerful interactive environment in which the user has access to all variables in the code database. 10 refs., 3 figs.

An aluminum piston tank has been developed for applications requiring lightweight, low cost, low pressure, positive-expulsion liquid storage. The 3 liter (183 in{sup 3}) vessel is made primarily from aluminum sheet, using production forming and joining operations. The development process relied mainly on pressurizing prototype parts and assemblies to failure, as the primary source of decision making information for driving the tank design toward its optimum minimum-mass configuration. Critical issues addressed by development testing included piston operation, strength of thin-walled formed shells, alloy choice, and joining the end cap to the seamless deep drawn can. 9 refs., 8 figs.

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Using the theories presented in DOE Orders 4700.1, 1332.1A, and Notice 4700.5 as the basis for system design, the Fernald Environmental Restoration Management Corporation (FERMCO) has developed and implemented a Project Control System (PCS) that complies with requirements and provides DOE and FERMCO management with timely performance measurement information. To this extent, the FERMCO PCS probably is similar to the systems of the majority of the contractors in the DOE complex. In fact. this facet of the FERMCO PCS generally mirrors those used on projects around the world by FERMCO`s parent company, Fluor Daniel. Starting with this {open_quotes}platform{close_quotes}, the vision and challenge of creating a fully integrated system commenced. An open-architecture systems approach is the factor that most greatly influenced and enabled the successful development and implementation of the Project Control System for the Fernald Environmental Management Project. All aspects of a fully integrated system were considered during the design phase. The architecture of the FERMCO system enables seamless, near real-time, transfer of data both from and to the Project Control System with all other related systems. The primary systems that provide and share data with the Project Control System include those used by the Payroll, Accounting, Procurement, and Human …

Cleanup of hazardous waste sites under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) is a complicated and painstaking process, particularly at facilities with a multitude of individual hazardous waste sites, each having a multitude of chemicals and radonuclides. The US Department of Energy-Oak Ridge, Environmental Restoration Division (DOE-OR/ERD) administers five such facilities which are undergoing environmental cleanup under the CERCLA Remedial Investigation and Feasibility Study (RI/FS) process or the Resource Conservation and Recovery Act (RCRA) investigation process. The nature of the wastes treated, stored, or disposed of at the US DOE-OR sites is heterogeneous and often unknown. The amount of environmental sampling, chemical analysis, and document preparation and review required to support a baseline risk assessment alone at each facility often requires years before arriving at a final Record of Decision. Therefore, there is clearly a need to streamline the investigative and decision processes in order to realize the US Environmental Protection Agency`s (EPA) goal of reducing contaminant levels to those that are protective human health and the environment in a timely and cost-effective manner.

The full spectrum of occupied and unoccupied {sigma} and {pi} orbitals is presented for solid C{sub 60}, C{sub 70}, and graphite, using Cls emission and absorption spectroscopy. There are significant differences between C{sub 60} and C{sub 70}, and even larger changes relative to their infinite analog graphite C{sub {infinity}}. A comparison is made with photoemission and inverse photoemission results, along with first principles quasiparticle calculations.

The design of the magnet for the GEM detector at the SSC is described. It is an 18m inner diameter, 30m long superconducting solenoid, with a magnetic field of 0.8T. The basic solenoidal field is shaped by large ferromagnetic cones, to improve detector performance in the ends of the solenoid. Because of the system`s large size and mass, field-fabrication on-site at SSC is required. The challenges in this process, together with the large stored energy of the system, 2.5 GJ, have lead to novel design choices in several areas, including the conductor. The design of the conductor, cold mass, vacuum vessel, cold mass supports, thermal shields, forward field shapers, and auxiliary systems are described.

Since the advent of SN 1987A considerable progress has been made in our understanding of supernova explosions. It is now realized that they are intrinsically multidimensional in nature due to the various hydrodynamical instabilities which take place at almost all stages of the explosion. These instabilities not only modify the observables from the supernova, but are also thought to be at the heart of the supernova mechanism itself, in a way which guarantees robust and self-regulated explosions. In this paper, we review these instabilities placing them into their appropriate context and identifying their role in the genesis of core collapse supernovas.

In this study we present a new cloud treatment in an atmospheric climate model. The water (or ice) content of clouds is a introduced as a prognostic variable, subject to both advective and diffusive transport. In the first phase of the study, the cloud water does not affect the radiative properties of clouds. We then find differences in precipitation and cloud fields, but little effect on the overall climate. In the second phase the cloud water determines the reflectivity of the clouds. This causes large changes in the global circulation, largely due to enhanced reflection from high tropical cirrus clouds. As a third step, the cloud emissivity is also based on the cloud water content. This greatly enhances the outgoing terrestrial radiation and brings the model`s radiative budget quite close to the observed.

The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a small angle. Given the observed distribution of stars in the sky, the need to find a tilt reference star quite close to the object restricts the fraction of the sky over which long-exposure images with diffraction limited resolution can be obtained. In this paper, the authors present a comprehensive performance analysis of tip-tilt compensation systems that use a natural star as a tilt reference, taking into account properties of the atmosphere and of the Galactic stellar populations, and optimizing over the system operating parameters to determine the fundamental limits to the long-exposure resolution. Their results show that for a ten meter telescope on Mauna Kea, if the image of the tilt reference star is uncorrected, about half the sky can be imaged in the V …

Often the tasks of a parallel job compute sets of values that are reduced to a single value or gathered to build an aggregate structure. Since reductions may introduce dependencies, most languages separate computation and reduction. For example, Fortran 90 and HPF provide a rich set of predefined reduction functions but only for extant arrays. Sisal 1.2 is unique in that it supports seven reduction operations as a natural consequence of loop expressions. These reductions are limited and cannot express the variety of reduction operations found in parallel programs. In this paper, the authors present compilation techniques that recognize pairs of computation-reduction expressions in Sisal 1.2 and fuse them into single parallel loops. This optimization overlaps computation and reduction, reduces runtime overhead, and reduces storage requirements. They describe an implementation and they present performance numbers that demonstrate the utility of their techniques.

We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

The proposed cooling system for the muon collider will consist of a 200 meter long line of alternating field straight solenoids interspersed with bent solenoids. The muons are cooled in all directions using a 400 mm long section liquid hydrogen at high field. The muons are accelerated in the forward direction by about 900 mm long, 805 MHz RF cavities in a gradient field that goes from 6 T to -6 T in about 300 mm. The high field section in the channel starts out at an induction of about 2 T in the hydrogen. As the muons proceed down the cooling channel, the induction in the liquid hydrogen section increases to inductions as high as 30 T. The diameter of the liquid hydrogen section starts at 750 mm when the induction is 2 T. As the induction in the cooling section goes up, the diameter of the liquid hydrogen section decreases. When the high field induction is 30 T, the diameter of the liquid hydrogen section is about 80 mm. When the high field solenoid induction is below 8.5 T or 9T, niobium titanium coils are proposed for generating .the magnetic field. Above 8.5 T or 9 T to …

The interaction region (IR) quadrupoles [1] for the Relativistic Heavy Ion Collider (RHIC)[2]are the best field quality superconducting magnets ever built for any major accelerator. This field quality is primarily achieved with the help of eight tuning shims [3] that remove the residual errors from a magnet after it is built and tested. These shims overcome the limitations from the typical tolerances in parts and manufacturing. This paper describes the tuning shims and discusses the evolution of a flexible approach that allowed changes in the design parameters and facilitated using parts with significant dimensional variations while controlling cost and maintaining schedule and field quality. The RHIC magnet program also discovered that quench and thermal cycles cause small changes [4]in magnet geometry. The ultimate field quality performance is now understood to be determined by these changes rather than the manufacturing tolerances or the measurement errors.

We present comparisons of various statistical theories for effective pair interactions (EPI) in alloys. We then evaluate these EPI`s using the Cowley theory, the Krivoglaz-Clapp-Moss (KCM) approximation, the {gamma}-expansion method (GEM) of Tokar, Masanskii and coworkers, and the exact inverse Monte Carlo (IMC) method, introduced by Gerold and Kern. Via a series of model calculations on a hypothetical bcc alloy with a single nearest-neighbor interaction we show that the Cowley theory is successful in evaluating the EPI`s in more dilute alloys but tends to overestimate the magnitude of the nearest neighbor energy at higher concentrations, whereas the KCM expression becomes increasingly inaccurate at lower concentrations. In general, however, the approximate mean field theories are most accurate at higher concentrations and higher temperatures. Recent studies of short-range order in single crystals are discussed in which these EPI`s have been evaluated using the IMC, KCM, GEM and Cowley theories. Examples include the bcc alloy Fe{sub 0.53}Cr{sub 0.47} and the fcc alloys Cu{sub 3} Au, CU{sub 0.69}Zn{sub 0.31} and Ni{sub 0.89}BgCr{sub 0.11}. In all cases the approximate expressions do quite well, especially the GEM.

The authors describe and test spai_1.1, a parallel MPIimplementation of the sparse approximate inverse (SPAI) preconditioner.They show that SPAI can be very effective for solving a set of very largeand difficult problems on a Cray T3E. The results clearly show the valueof SPAI (and approximate inverse methods in general) as the viablealternative to ILU-type methods when facing very large and difficultproblems. The authorsstrengthen this conclusion by showing that spai_1.1also has very good scaling behavior.

In the rush to explore the B system, one should not ignore the potential of rare K decays. The charged and neutral FCNC K {yields} {pi}{nu}{bar {mu}} decays are theoretically very clean, on a par with B {yields} {psi}K{sub S}, which measures {beta}, and much less problematic than B {yields} {pi}{pi} and B{sub s} {yields} K{sup +}K{sup -} or B{sub s} {yields} K*{sup +}K*{sup -} which have been proposed to measure {alpha} and {gamma} respectively. B(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}), which in the Standard Model yields information on |V*{sub ts}V{sub td}|, is closely related to the ratio of B{sub d} - {bar B}{sub d} to B{sub s}-{bar B}{sub s}, mixing, which yields |V{sub td}/V{sub ts}|. It is essential to compare such clean measurements from the B and K sectors, because new physics is likely to manifest itself in apparent disagreements[12]. Measuring the branching ratios of K {yields} {pi}{nu}{bar {nu}} decays is a challenge, but the current proven reach in sensitivity for the charged mode and the prospect of measuring the neutral mode at AGS-2000 indicate that this window into flavor physics is on the verge of becoming an exploitable reality.

In the National Ignition Facility (NIF), currently under design and construction at Lawrence Livermore National Laboratory (LLNL), 192 high-power laser beamlines incorporating over 8,000 large optics, are focused onto a target smaller than a dime. The actual laser path will be contained within the Laser Target Area Building (LTAB), but the smaller adjacent building, the Optics Assembly Building, is where the optic modules are assembled and aligned. After the optics are finished in the OAB they must be transported and installed into the LTAB. While this is done strict cleanliness and handling conditions must be maintained. To maximize the efficiency of this process the optics are assembled into Line Replaceable Units (LRUs), which typically consist of a mechanical housing, laser optics, utilities, actuators and kinematic mounts. In this paper the Optical Transport and Material Handling designs that will be used to deliver the LRUs into the NIF laser bays are presented. Five types of delivery systems have been developed to deliver the LRUs to their locations in the LTAB. They are top loading, bottom loading, side loading, switchyard loading and target area loading. The first three operate in the laser bay of the LTAB and are transported between the OAB …