We report the results of first-principles density functional theory calculations of the Young's modulus and other mechanical properties of hydrogen-passivated Si {l_angle}001{r_angle} nanowires. The nanowires are taken to have predominantly {l_brace}100{r_brace}surfaces, with small {l_brace}110{r_brace} facets according to the Wulff shape. The Young's modulus, the equilibrium length and the constrained residual stress of a series of prismatic beams of differing sizes are found to have size dependences that scale like the surface area to volume ratio for all but the smallest beam. The results are compared with a continuum model and the results of classical atomistic calculations based on an empirical potential. We attribute the size dependence to specific physical structures and interactions. In particular, the hydrogen interactions on the surface and the charge density variations within the beam are quantified and used both to parameterize the continuum model and to account for the discrepancies between the two models and the first-principles results.

In 2004, the Department of Energy (DOE) directed Westinghouse Savannah River Company (WSRC) to develop a Caustic-Side Solvent Extraction (CSSX) process at the Savannah River Site (SRS) capable of removing cesium from 1 million gallons a year of dissolved salt solution. This facility would provide interim processing for cesium containing salt solution until the Salt Waste Processing Facility (SWPF) comes on-line. The DOE design inputs1 were to utilize contactors similar in design to those to be used in the SWPF, assume class C waste with less than 0.5 Ci/gal Cs-137, achieve a Decontamination Factor (DF) greater than 12, include the ability to clean the contactors in place, and assume an operating life of three years. WSRC embarked on a design, test, and build program to achieve these criteria as described in the following text. All DOE design criteria have been met or exceeded by WSRC.

We present the new and updated BABAR measurements of CP-violation studies for many b{yields}s penguin decay modes. We report the first observation of mixing-induced CP-violation in B{sup 0}{yields}{eta}{prime}K{sup 0} with a significance (including systematic uncertainties) of 5.5{sigma}. We also present the first observation of the decay B{sup 0} {yields} {rho}{sup 0}K{sup 0}. Using the time-dependent Dalitz plot analysis of B{sup 0} {yields} K{sup +}K{sup -}K{sup 0} decay, the CP-parameters A{sub CP} and {beta}{sub eff} are measured with 4.8{sigma} significance, and we reject the solution near {pi}/2 -- {beta}{sub eff} at 4.5 {sigma}. We also present the update measurements of CP-violating parameters for B{sup 0} {yields} K{sup 0}{sub S}{pi}{sup 0}, K{sup 0}{sub S}K{sup 0}{sub S}K{sup 0}{sub S} and {pi}{sup 0}{pi}{sup 0}K{sup 0}{sub S} decays. An updated measurements of the CP-violating charge asymmetries for B{sup {+-}} {yields} {eta}{prime}K{sup {+-}}, {eta}K{sup {+-}} {omega}{eta}K{sup {+-}} decays are also presented. The measurements are based on the data sample recorded at the {Upsilon}(4S) resonance with BABAR detector at the PEP-II B-meson Factory at SLAC.

We report a full-vector, three-dimensional, numerical solution of Maxwell's equations for optical propagation within, and scattering by, a random medium of macroscopic dimensions. The total scattering cross-section is determined using the pseudospectral time-domain technique. Specific results reported in this Paper indicate that multiply scattered light also contains information that can be extracted by the proposed cross-correlation analysis. On a broader perspective, our results demonstrate the feasibility of accurately determining the optical characteristics of arbitrary, macroscopic random media, including geometries with continuous variations of refractive index. Specifically, our results point toward the new possibilities of tissue optics--by numerically solving Maxwell's equations, the optical properties of tissue structures can be determined unambiguously.

The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Dark Matter and New Physics Working group has been developing approaches for the indirect detection of in situ annihilation of dark matter. Our work has assumed that a significant component of dark matter is a new type of Weakly Interacting Massive Particle (WIMP) in the 100GeV mass range. The annihilation of two WIMPs results in the production of a large number of high energy gamma rays (>1GeV) that can be well measured by the GLAST LAT. The cold dark matter model implies a significant number of as yet unobserved dark matter satellites in our galaxy. The spectra of these galactic satellites are considerably harder than most, if not all, astrophysical sources, have an endpoint at the mass of the WIMP, and are not power laws. We describe a preliminary feasibility study for the indirect detection of dark matter satellites in the Milky Way using the GLAST LAT.

The threat of nuclear terrorism has become a global concern. Many countries continue to make efforts to strengthen nuclear security by enhancing systems of nuclear material protection, control, and accounting (MPC&A). Though MPC&A systems can significantly upgrade nuclear security, they do not eliminate the "human factor." This paper will describe some of the key elements of a comprehensive, sustainable nuclear security culture enhancement program and how implementation can mitigate the insider threat.

Molecular beam epitaxy was used to deposit body centered cubic single crystal Fe{sub 1-x}Ga{sub x} thin films on MgO(001) and ZnSe/GaAs(001) substrates well beyond the bulk stability concentration of about 28%. The crystal quality of the substrate surface and each deposited layer was monitored in situ by reflection high energy electron diffraction. The magnetization of the samples as a function of Ga is found to decrease more rapidly than a simple dilution effect, and element-specific x-ray magnetic circular dichroism ascribes this trend to a decrease in the Fe moment and an induced moment in the Ga that is antialigned to the Fe moment.

This paper describes how a passive quench protection system can be applied to long superconducting solenoid magnets. When a solenoid coil is long compared to its thickness, the magnet quench process will be dominated by the time needed for uench propagation along the magnet length. Quench-back will permit a long magnet to quench more rapidly in a passive way. Quenchback from a conductive (low resistivity) mandrel is essential for spreading the quench along the length of a magnet. The andrel must be inductively coupled to the magnet circuit that is being quenched. Current induced in the mandrel by di/dt in the magnet produces heat in the mandrel, which in turn causes the superconducting coil wound on the mandrel to quench. Sub-divisions often employed to reduce the voltages to ground within the coil. This paper explores when it is possible for quench-back to be employed for passive quench protection. The role of sub-division of the coil is discussed for long magnets.

Synchrotron-based X-ray microtomography (micro CT) at the Advanced Light Source (ALS) line 8.3.2 at the Lawrence Berkeley National Laboratory produces three-dimensional micron-scale-resolution digital images of the pore space of the reservoir rock along with the spacial distribution of the fluids. Pore-scale visualization of carbon dioxide flooding experiments performed at a reservoir pressure demonstrates that the injected gas fills some pores and pore clusters, and entirely bypasses the others. Using 3D digital images of the pore space as input data, the method of maximal inscribed spheres (MIS) predicts two-phase fluid distribution in capillary equilibrium. Verification against the tomography images shows a good agreement between the computed fluid distribution in the pores and the experimental data. The model-predicted capillary pressure curves and tomography-based porosimetry distributions compared favorably with the mercury injection data. Thus, micro CT in combination with modeling based on the MIS is a viable approach to study the pore-scale mechanisms of CO{sub 2} injection into an aquifer, as well as more general multi-phase flows.

Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal …

The Muon Ionization Cooling Experiment (MICE) spectrometer solenoid magnets will be the first magnets to be installed within the MICE cooling channel. The spectrometer magnets are the largest magnets in both mass and surface area within the MICE ooling channel. Like all of the other magnets in MICE, the spectrometer solenoids are kept cold using 1.5 W (at 4.2 K) pulse tube coolers. The MICE spectrometer solenoid is quite possibly the largest magnet that has been cooled using small coolers. Two pectrometer magnets have been built and tested. This report discusses the results of current and cooler tests of both magnets.

YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) tapes carry significant amount of current at fields beyond the limit of Nb-based conductors. This makes the YBCO tapes a possible conductor candidate for insert magnets to increase the bore field of Nb{sub 3}Sn high-field dipoles. As an initial step of the YBCO insert technology development, two subscale racetrack coils were wound using Kapton-insulated commercial YBCO tapes. Both coils had two layers; one had 3 turns in each layer and the other 10 turns. The coils were supported by G10 side rails and waxed strips and not impregnated. The critical current of the coils was measured at 77 K and self-field. A 2D model considering the magnetic-field dependence of the critical current was used to estimate the expected critical current. The measured results show that both coils reached 80%-95% of the expected values, indicating the feasibility of the design concept and fabrication process.

Photocopy of an editorial from the Abilene Reporter News, section 4-A of the 1978-10-19 paper, discussing the passing and history of Gypsy Ted Sullivan Wylie. The photocopy has three duplicate images on the page.

Over the past several years, computational scientists have observed a frustrating trend of stagnating application performance despite dramatic increases in peak performance of high performance computers. In 2002, researchers at Lawrence Berkeley National Laboratory, Argonne National Laboratory, and IBM proposed a new process to reverse this situation [1]. This strategy is based on new types of development partnerships with computer vendors based on the concept of science-driven computer system design. This strategy will engage applications scientists well before an architecture is available for commercialization. The process is already producing results, and has further potential for dramatically improving system efficiency. This paper documents the progress to date and the potential for future benefits. An example of this process is discussed, using IBM Power architecture with a computer architecture design that can lead to a sustained performance of 50 to 100 Tflo p/s on a broad spectrum of applications in 2006 for a reasonable cost. This partnership will establish a collaborative approach to modifying computer architecture to enable heretofore unrealized achievements in computer capability-limited fields such as nanoscience, combustion modeling, fusion, climate modeling, and astrophysics.

Time periodic solutions are found for the natural convection of a Pr = 0.71 fluid in a differentially heated 8 x 1 cavity at Ra = 3.4 x 10{sup 5} using a ''straight'' Galerkin finite element method with the Q{sub 2}Q{sub 1} element. Time integration is performed with an implicit second-order accurate (in time) trapezoid rule. As expected, the average values of various solution metrics were relatively insensitive to mesh refinement and time integration truncation error, although coarse meshes tend to damp out the time periodic behavior. The amplitude and frequency of the oscillation is sensitive to both mesh and time truncation errors.

We have begun building the ''Mercury'' laser system as the first in a series of new generation diode-pumped solid-state lasers for inertial fusion research. Mercury will integrate three key technologies: diodes, crystals, and gas cooling, within a unique laser architecture that is scalable to kilojoule energy levels for fusion energy applications. The primary performance goals include 10% electrical efficiencies at 10 Hz and 100 J with a 2-10 ns pulse length at 1.047 pm wavelength. When completed, Mercury will allow rep-rated target experiments with multiple target chambers for high energy density physics research.

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This paper describes a work in progress on using multiple sets of input features for robust real-time object tracking in image sequences. Traditional approaches to tracking relied mostly on segmentation of the intensity data using motion or appearance data. Recent availability of real-time range data allows us to use it as an additional unrivaled source of information. We propose a combination of intensity- and range-based input features. Range data enables localized search for' specific features which improves tracking reliability and speed. Proposed approach was successfully tested for the face and gesture tracking application.

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An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

The growth of Cu Layers deposited on Ru(0001) substrates at temperatures between 500 K and 850 K was studied using surface x-ray diffraction. Results are consistent with a Stransky-Krastanov growth mode with a two layer critical thickness.

Normal form analysis and tracking results show that both normal and skew resonances are driven strongly by the nonlinear fields of the IR quadrupoles. We report here on the possibility of improving the dynamic aperture by compensating these resonances with the use of correctors placed in the IRs. The effectiveness of local correction schemes in the presence of beam-beam interactions is also studied.

Silicon Vertex tracks are of fundamental importance for reconstructing B meson decays at a hadron collider. The upgraded CDF detector will deploy an online Silicon Vertex Tracker in the level 2 trigger. We have studied how this new device exploits the Tevatron large B meson production to select hadronic B decays fundamental for measuring CP violation and B{sub s} mixing.

Grain growth experiments and simulations exhibit self-similar grain size distributions quite different from that derived via a mean field approach by Hillert [ 1]. To test whether this discrepancy is due to insufficient anneal times, two different two-dimensional grain structures with realistic topologies and Hillert grain size distributions are generated and subjected to grain growth via the Monte Carlo Potts Model (MCPM). In both cases, the observed self-similar grain size distributions deviate from the initial Hillert form and conform instead to that observed in MCPM grain growth simulations that start from a random microstructure. This suggests that the Hillert grain size distribution is not an attractor.