The lower boundary condition of sea surface temperature (SST) and sea-ice concentration (sic) is a critical forcing of the lower frequencies in multi-decadal global atmospheric reanalyses such as ERA-40. Partly in response to the ERA-40 project, new SST/sic data sets have been developed that are considerably improved over those available to the first-generation reanalyses. This paper documents the input SST/sic data sets and the processing that created the daily SST/sic specification for the ERA-40 period 1956-2001. The source data are: (1) the monthly mean HadISST data set from the UKMO Hadley Centre for 1956-1981; and (2) the weekly NCEP 2DVAR data for 1982-present. Both data sets are reanalyses of satellite and conventional SST/sic observations. The principal reason for the higher quality of these source data sets is the use of a common consensus sic and a common sic-SST relationship in the sea ice margins. The use of a common sic resulted in a very smooth transition between HadISST and NCEP 2DVAR, despite differences in data assimilation techniques and monthly versus weekly analyses. No special action was required to insure consistency at the transition unlike as was necessary for the AMIP II experiment (Fiorino, 1997). The only special processing was application …

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Rheological and physical properties testing were conducted on actual AN-107 and AW-101 pretreated feed samples prior to the addition of glass formers. Analyses were repeated following the addition of glass formers. The AN-107 and AW-101 pretreated feeds were tested at the target sodium values of nominally 6, 8, and 10 M. The AW-101 melter feeds were tested at these same concentrations, while the AN-107 melter feeds were tested at 5, 6, and 8 M with respect to sodium. These data on actual waste are required to validate and qualify results obtained with simulants.

Wet-etch figuring (WEF), a computer-controlled method for generating arbitrarily shaped optical surfaces using wet chemical etching, has been developed. This method uses applicator geometry and surface tension gradients (the Marangoni Effect) to define and confine the footprint of a wetted etchant zone on the surface. Capillary forces attach the flowing etchant solution to the underside of the optic being figured. No mechanical or thermal stresses or residues are applied to the optic by this process. This enables interferometric measurement of the glass thickness while surfacing, which then controls the placement and dwell time of the wetted zone. The result is a truly deterministic, closed-loop figuring process with a high degree of optical precision. This process can figure sub-millimeter thickness, large-aperture plates or sheets that are very difficult to finish by conventional methods. Automated linear and circular spot etching tools were used to demonstrate surfacing on 380 micron-thick glass sheets, to Strehl better than 0.8, as specified by data array or Zernike polynomials.

We have developed an Integrated Vehicle Simulation Testbed (InVeST). InVeST is based on the concept of Co-simulation, and it allows the development of virtual vehicles that can be analyzed and optimized as an overall integrated system. The virtual vehicle is defined by selecting different vehicle components from a component library. Vehicle component models can be written in multiple programming languages running on different computer platforms. At the same time, InVeST provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all vehicle components. InVeST has been recently demonstrated using a transmission model and a transmission controller model. The transmission model was written in SABER and ran on a Sun/Solaris workstation, while the transmission controller was written in MATRIXx and ran on a PC running Windows NT. The demonstration was successfully performed. Future plans include the applicability of Co-simulation and InVeST to analysis and optimization of multiple complex systems, including those of Intelligent Transportation Systems.

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (fuel flexibility, lower energy requirement for hydrogen liquefaction and reduced evaporative losses). The work described here is directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen. The use of commercially available pressure vessels significantly reduces the cost and complexity of the insulated pressure vessel development effort. This paper describes a series of tests that have been done with aluminum-lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. All analysis and experiments to date indicate that no significant damage has resulted. Required future tests are described that will prove that no technical barriers exist to the safe use of aluminum-fiber vessels at cryogenic temperatures. Future activities also include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for obtaining certification for insulated pressure vessels.

We performed Monte Carlo calculations of the neutron and gamma ray spectra and neutron and gamma dose rates outside the shielding of the UF{sub 6} mass flowmeter. The UF{sub 6} mass flowmeter and the UF{sub 6} mass flowmeter are the two main components of the Blend Down Monitoring System (BDMS) equipment. The BDMS equipment is designed to continuously monitor the UF{sub 6} enrichment and mass flow rates in processing pipes at uranium facilities. The UF{sub 6} mass flowmeter incorporates four {sup 252}Cf neutron sources, surrounded by a polyethylene shielding block. The uranium fission products generated by the {sup 252}Cf neutrons are detected down the pipe, thus confirming the UF{sub 6} mass flow rate. The dose calculations used both U.S. and Russian gamma and neutron fluence-to-dose conversion coefficients. The purpose of these calculations was to facilitate proper interpretation of the neutron dose rate measurements from rem meters (e.g., rem balls) outside of BDMS shielding. An accurate determination of the dose rate is particular interest in that it enables dose rates to be compared with the applicable regulatory limit. The calculations show that neutrons outside of BDMS shielding are significantly reduced in energy, i.e., the spectrum is shifted (i.e., moderated) towards lower …

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Increasingly in industry, software design and implementation is object-oriented, developed in C++ or Java, and relies heavily on pre-existing software libraries (e.g. the Microsoft Foundation Classes for C++, the Java API for Java). A similar but more tentative trend is developing in high-performance parallel scientific computing. The transition from serial to parallel application development considerably increases the need for library support: task creation and management, data distribution and dynamic redistribution, and inter-process and inter-processor communication and synchronization must be supported. PADRE is a library to support the interoperability of parallel applications. We feel there is significant need for just such a tool to compliment the many domain-specific application frameworks presently available today, but which are generally not interoperable.

The quest for metallic hydrogen has been going on for over one hundred years. Before hydrogen was first condensed into a liquid in 1898, it was commonly thought that condensed hydrogen would be a metal, like the monatomic alkali metals below hydrogen in the first column of the Periodic Table. Instead, condensed hydrogen turned out to be transparent, like the diatomic insulating halogens in the seventh column of the Periodic Table. Wigner and Huntington predicted in 1935 that solid hydrogen at 0 K would undergo a first-order phase transition from a diatomic to a monatomic crystallographically ordered solid at {approx}25 GPa. This first-order transition would be accompanied by an insulator-metal transition. Though searched for extensively, a first-order transition from an ordered diatomic insulator to a monatomic metal is yet to be observed at pressures up to 120 and 340 GPa using x-ray diffraction and visual inspection, respectively. On the other hand, hydrogen reaches the minimum electrical conductivity of a metal at 140 GPa, 0.6 g/cm{sup 3}, and 3000 K. These conditions were achieved using a shock wave reverberating between two stiff sapphire anvils. The shock wave was generated with a two-stage light-gas gun. This temperature exceeds the calculated melting temperature …

An integrating solid state detector with segmentation has been developed that addresses the needs in scanning transmission x-ray microscopy below 1 keV photon energy. The detector is not cooled and can be operated without an entrance window which leads to a total photon detection efficiency close to 100%. The chosen segmentation with 8 independent segments is matched to the geometry of the STXM to maximize image mode flexibility. In the bright field configuration for 1 ms integration time and 520 eV x-rays the rms noise is 8 photons per integration.

Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx} 100 ns) for the extracted beam pulse must …

Single solid-state devices or arrays of solid-state devices are being incorporated into many pulsed power applications as a means of generating fast, high-power, high repetition-rate pulses and ultimately replacing hard tubes and thyratrons. While vendors' data sheets provide a starting point for selecting solid-state devices, most data sheets do not have sufficient information to determine performance in a pulsed application. To obtain this relevant information, MOSFET's and IGBT's from a number of vendors have been tested to determine rise times, fall times and current handling capabilities. The emphasis is on the evaluation of devices that can perform in the range of 100ns pulse widths and the test devices must be capable of switching 1000 volts or greater at a pulsed current of at least 25 amperes. Additionally, some devices were retest with a series magnetic switch to evaluate the effects on switching parameters and specifically rise times. All devices were evaluated under identical conditions and the complete test results are presented.

Modern antennas especially arrays are being placed in layers of materials on complex environments. This technique produces aesthetically pleasing structures if necessary, allows for more freedom in structure planning, and can improve antenna performance. In the past, buried antennas have been studied by numerous authors such as in Reference. Recent work on this subject uses spectral and/or numerical moment method formulations. For high frequency analysis it is important to find efficient and accurate methods for design purposes. A rigorous recursive method for plane waves reflection and transmission coefficients by Richmond has been used in the past for dipoles above multilayer slabs. This solution is modified in this paper to account for forward and backward traveling rays with appropriate spread factors for a dipole in the media. Extensive validation for this approximate method shows good agreement with a Method of Moments code. This code is developed at Lawrence Livermore National Laboratory. The geometry for these comparisons uses a dipole in nontruncated dielectric multilayer slabs.

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Major improvements in models of chemically peculiar stars have been achieved in the past few years. With these new models it has been possible to test quantitatively some of the processes involved in the formation of abundance anomalies and their effect on stellar structure. The models of metallic A (Am) stars have shown that a much deeper mixing has to be present to account for observed abundance anomalies. This has implications on their variability, which these models also reproduce qualitatively. These models also have implications for other chemically inhomogeneous stars such as HgMn B stars which are not known to be variable and {lambda} Booetis stars which can be. The study of the variability of chemically inhomogeneous stars can provide unique information on the dynamic processes occurring in many types of stars in addition to modeling of the evolution of their surface composition.

In this paper we will describe the synthesis of several amino- and nitro-substituted heterocycles, examples from a continuing research project targeted at the synthesis of new, insensitive energetic materials that possess at least 80% the power of HMX (28% more power than TATB). Recently we reported the synthesis and scale-up of the insensitive energetic material, 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105). The energy content (81% the power of HMX) and thermal stability of LLM-105 make it a viable candidate material for insensitive boosters and deep oil perforation. We will report on recent synthetic improvements and several performance and safety tests performed on LLM-105, including a 1 in. cylinder shot and plate dent. We will also report on the synthesis and characterization of 4-amino-3,5-dinitropyrazole (LLM-116), an interesting new insensitive energetic material with a measured crystal density of 1.90 g/cc, to our knowledge the highest density yet measured for a five-membered heterocycle containing amino- and nitro-substituents. LLM-116 was synthesized by reacting 3,5-dinitropyrazole with 1,1,1-trimethylhydrazinium iodide (TMHI) in DMSO in the presence of base. The synthesis and characterization of 4-amino-5-nitro-1,2,3-triazole (ANTZ) and 43-dinitro-1,2,3-triazole (DNTZ), first described by Baryshnikov and coworkers, will also be presented along with the synthesis of several new energetic materials derived from ANTZ and …

The deployment and operation of large wireless sensor networks can pose difficult problems, particularly in time critical situations, over large geographic areas, or in rugged terrain. An approach to this problem is to use unmanned air vehicles to first deploy the sensors, and then provide communication services to the sensors. This paper presents a network model that describes the flow of data through such a sensor network. Simulation results are presented that illustrate the behavior of the data flow in steady state and transient conditions.

This paper presents a proposal for modifying the current employee annual evaluation process in SCAD. It purports to simplify that process, primarily by breaking up the resultant document into a set of more or less independent components. It claims to reduce the overall time and effort required from each actor.

In phase two of the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT-II), four electron beam pulses of variable pulse length strike an X-ray converter target to produce time-resolved X-ray image. An important requirement for the converter target is to minimize the hydrodynamic expansion of the converter material so that there is enough material to generate the required X-ray dose for all four pulses. Minimizing the hydrodynamic expansion is also important from the standpoint of beam transport. If there is too much expansion of the converter material, the spot-size of the beam will deteriorate due to the charge neutralization of the beam by the target plasma. The beam spot size can also be deteriorated by backstreaming ions. However, this effect can be minimized by placing a barrier foil in front of the target. In this paper, we present a converter target design, based on the simulations using the radiation hydrodynamics code LASNEX and the Monte Carlo radiation transport code MCNP, that can produce the required X-ray dose for all four pulses with tolerable X-ray spot size variation. Our calculations also show that the barrier foil may block the backstreaming ions for all four pulses.

The High Average Power Laser Program (HAPL) is a multi-institutional, coordinated effort to develop a high-energy, repetitively pulsed laser system for Inertial Fusion Energy and other DOE and DOD applications. This program is building a laser-fusion energy base to complement the laser-fusion science developed by DOE Defense programs over the past 25 years. The primary institutions responsible for overseeing and coordinating the research activities are the Naval Research Laboratory (NRL) and LLNL. The current LLNL proposal is a companion proposal to that submitted by NRL, for which the driver development element is focused on the krypton fluoride excimer laser option. Aside from the driver development aspect, the NRL and LLNL companion proposals pursue complementary activities with the associated rep-rated laser technologies relating to target fabrication, target injection, final optics, fusion chamber, materials and power plant economics. This report requests continued funding in FY02 to support LLNL in its program to build a 1kW, 100J, diode-pumped, crystalline laser. In addition, research in high gain laser target design, fusion chamber issues and survivability of the final optic element will be pursued. These technologies are crucial to the feasibility of inertial fusion energy power plants and also have relevance in rep-rated stewardship experiments.

A proposed stave design for the D0 Run IIb silicon tracker outer layers featuring central cooling channels and a composite shell mechanical structure is evaluated for self-deflection and deflection due to external loads. This paper contains an introduction to the stave structure, a section devoted to composite lamina and laminate properties and finally a section discussing the beam deflections expected for assembled staves using these laminates.

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