The total photo-absorption cross section of {sup 4}He is evaluated microscopically using two- (NN) and three-nucleon (NNN) interactions based upon chiral effective field theory ({chi}EFT). The calculation is performed using the Lorentz integral transform method along with the ab initio no-core shell model approach. An important feature of the present study is the consistency of the NN and NNN interactions and also, through the Siegert theorem, of the two- and three-body current operators. This is due to the application of the {chi}EFT framework. The inclusion of the NNN interaction produces a suppression of the peak height and enhancement of the tail of the cross section. We compare to calculations obtained using other interactions and to representative experiments. The rather confused experimental situation in the giant resonance region prevents discrimination among different interaction models.

In today's world, the use of parallel programming and architectures is essential for simulating practical problems in engineering and related disciplines. Remarkable progress in CPU architecture (multi- and many-core, SMT, transactional memory, virtualization support, etc.), system scalability, and interconnect technology continues to provide new opportunities, as well as new challenges for both system architects and software developers. These trends are paralleled by progress in parallel algorithms, simulation techniques, and software integration from multiple disciplines. In its 6th year ParSim continues to build a bridge between computer science and the application disciplines and to help with fostering cooperations between the different fields. In contrast to traditional conferences, emphasis is put on the presentation of up-to-date results with a shorter turn-around time. This offers the unique opportunity to present new aspects in this dynamic field and discuss them with a wide, interdisciplinary audience. The EuroPVM/MPI conference series, as one of the prime events in parallel computation, serves as an ideal surrounding for ParSim. This combination enables the participants to present and discuss their work within the scope of both the session and the host conference. This year, ten papers with authors in ten countries were submitted to ParSim, and after a quick …

Maintaining a smaller, aging U.S. nuclear weapons stockpile without underground nuclear testing requires the capability to verify and validate the complex computer calculations on which stockpile confidence is based. This capability, in turn, requires nonnuclear hydrodynamic tests (hydrotests) that can x-ray stages of the implosion process, providing freeze-frame photos of materials imploding at speeds of more than 16,000 kilometers per hour. The images will yield important information on shapes and densities of metals and other materials under the extreme pressures and temperatures generated by the detonation of high explosives. The Dual-Axis Radiographic Hydrodynamics Test (DARHT) Facility at Los Alamos national Laboratory is a two-arm x-ray imaging system that will provide such images, capturing the inner workings of a mock nuclear explosion with high resolution. Scientists compare the radiographic images with computer models, examine the differences, and refine the models to more accurately represent weapon behavior. One of DARHT's arms (now called DARHT-II) recently got a ''leg up'' through a collaboration of Lawrence Livermore and Los Alamos scientists, using a Livermore accelerator to test its subsystems and codes.

Age is one of the most important risk factors for human malignancies, including breast cancer; in addition, age-at-diagnosis has been shown to be an independent indicator of breast cancer prognosis. However, except for inherited forms of breast cancer, there is little genetic or epigenetic understanding of the biological basis linking aging with sporadic breast cancer incidence and its clinical behavior.

As flight speed increases, aerodynamic drag rises more sharply than the availability of atmospheric oxygen. The ratio of oxygen mass flux to dynamic pressure cannot be improved by changing altitude. The maximum possible speed for airbreathing propulsion is limited by the ratio of air capture area to vehicle drag area, approximately Mach 6 at equal areas. Simulation of vehicle acceleration shows that the use of atmospheric oxygen offers a significant potential for minimizing onboard consumables at low speeds. These fundamental calculations indicate that a practical airbreathing launch vehicle would accelerate to near steady-state speed while consuming only onboard fuel, then transition to rocket propulsion. It is suggested that an aircraft carrying a rocket-propelled vehicle to approximately Mach 5 could be a realistic technical goal toward improving access to orbit.

Previous studies had been done in order to show the attenuation of alpha particles in filter media. These studies provided an accurate correction for this attenuation, but there had not yet been a study with sufficient results to properly correct for attenuation due to dust loading on the filters. At the Savannah River Site, filter samples are corrected for attenuation due to dust loading at 20%. Depending on the facility the filter comes from and the duration of the sampling period, the proper correction factor may vary. The objective of this study was to determine self-absorption curves for each of three counting instruments. Prior work indicated significant decreases in alpha count rate (as much as 38%) due to dust loading, especially on filters from facilities where sampling takes place over long intervals. The alpha count rate decreased because of a decrease in the energy of the alpha. The study performed resulted in a set of alpha absorption curves for each of three detectors. This study also took into account the affects of the geometry differences in the different counting equipment used.

Purpose. This study was designed to elucidate the role of amplification at 8q24 in the pathophysiology of ovarian and breast cancer since increased copy number at this locus is one of the most frequent genomic abnormalities in these cancers. Experimental Design. To accomplish this, we assessed the association of amplification at 8q24 with outcome in ovarian cancers using FISH to tissue microarrays and measured responses of ovarian and breast cancer cell lines to specific small interfering RNAs (siRNA) against the oncogene, MYC, and a putative noncoding RNA, PVT1, both of which map to 8q24. Results. Amplification of 8q24 was associated with significantly reduced survival duration. In addition, siRNA-mediated reduction in either PVT1 or MYC expression inhibited proliferation in breast and ovarian cancer cell lines in which they were both amplified and over expressed but not in lines in which they were not amplified/over expressed. Inhibition of PVT1 expression also induced a strong apoptotic response in cell lines in which it was over expressed but not in lines in which it was not amplified/over expressed. Inhibition of MYC, on the other hand, did not induce an apoptotic response in cell lines in which MYC was amplified and over expressed. Conclusions. These …

It is planned to use the highly corrosion resistant titanium grade 7 (Ti Gr 7) and a high strength titanium alloy (Ti Gr 29) to fabricate the drip shield for the Yucca Mountain repository. Ti Gr 7 contains 0.15% Palladium (Pd) to increase its corrosion performance, mainly under reducing conditions. It was important to determine the corrosion behavior of Ti Gr 7 in concentrated brines at temperatures higher than 100 C, which may represent the behavior of dust deliquescence solutions. Tests were performed in concentrated NaCl + KCl solutions containing also nitrates and fluorides. Results show that Ti Gr 7 was highly resistant to general and localized corrosion. Some specimens were polarized to potentials higher than 4 volts. None of the tightly creviced specimens suffered crevice corrosion. The presence of fluoride promoted localized corrosion around the edges of the crevice former.

Amorphous metal and ceramic thermal spray coatings have been developed that can be used to enhance the corrosion resistance of containers for the transportation, aging and disposal of spent nuclear fuel and high-level radioactive wastes. Iron-based amorphous metal formulations with chromium, molybdenum and tungsten have shown the corrosion resistance believed to be necessary for such applications. Rare earth additions enable very low critical cooling rates to be achieved. The boron content of these materials, and their stability at high neutron doses, enable them to serve as high efficiency neutron absorbers for criticality control. Ceramic coatings may provide even greater corrosion resistance for container applications, though the boron-containing amorphous metals are still favored for criticality control applications. These amorphous metal and ceramic materials have been produced as gas atomized powders and applied as near full density, non-porous coatings with the high-velocity oxy-fuel process. This paper summarizes the performance of these coatings as corrosion-resistant barriers, and as neutron absorbers. Relevant corrosion models are also discussed, as well as a cost model to quantify the economic benefits possible with these new materials.

First-principles methods are employed to calculate the ground-state atomic densities (or volumes) of {alpha}-Pu alloyed with Al, Ga, and Am. Three configurations for the alloying atom are considered. (1) It is located at the most open and energetically most favorably site. (2) It is located in the least open site. (3) It is randomly distributed within the {alpha}-Pu matrix. When alloyed with Al or Ga, {alpha}-Pu behaves similarly, it expands considerably for configurations (2) and (3), while for (1) only small changes of the density occurs. Interestingly, for Am the alloying effects are quite different from that of Al and Ga. Small expansion is noted for the ordered configurations (1) and (2), whereas for the disordered (3), only insignificant changes of the density take place. The bonding character is thus differently influenced in Pu by the addition of Al and Ga on one hand and Am on the other. This is consistent with the view that Al and Ga stabilize the {delta} over the {alpha} phase in Pu by a different mechanism than Am, as has been discussed in recent publications.

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CERES is a dilepton experiment at the CERN SPS, known for its observation of enhanced production of low mass efe- pairs in collisions between heavy nuclei [1]. The upgrade of CERES in 1997-1998 by a radial Time Projection Chamber (TPC) [2] allowed to improve the momentum resolution and the particle identification capability while retaining the cylindrical symmetry. The upgraded experiment is shown in Fig. 1. The upgrade also extended the sensitivity of CERES to hadrons and made possible results like those described below. The measurement of central Pb+Au collisions at the maximum SPS energy of 158 GeV per nucleon in the fall of 2000 was the first run of the fully upgraded CERES and at the same time the last run of this experiment. About 30 million Pb+Au collision events at 158 GeV per nucleon were collected, most of them with centrality within the top 7% of the geometrical cross section {sigma}{sub G} = 6.94 b. Small samples of the 20% and the minimum bias collisions, as well as a short run at 80 AGeV, were recorded in addition. The dilepton mass spectra from this experiment were published in [3]. In this talk I present two particular results of hadron …

Recent BABAR results for decays of B-mesons to combinations of non-charm mesons are presented. This includes B decays to two vector mesons, B {yields} {eta}{prime}({pi}, K, {rho}) modes, and a comprehensive Dalitz Plot analysis of B {yields} KKK decays.

Repeating earthquakes (REs) are sequences of events that have nearly identical waveforms and are interpreted to represent fault asperities driven to failure by loading from aseismic creep on the surrounding fault surface at depth. We investigate the occurrence of these REs along faults in central California to determine which faults exhibit creep and the spatio-temporal distribution of this creep. At the juncture of the San Andreas and southern Calaveras-Paicines faults, both faults as well as a smaller secondary fault, the Quien Sabe fault, are observed to produce REs over the observation period of March 1984-May 2005. REs in this area reflect a heterogeneous creep distribution along the fault plane with significant variations in time. Cumulative slip over the observation period at individual sequence locations is determined to range from 5.5-58.2 cm on the San Andreas fault, 4.8-14.1 cm on the southern Calaveras-Paicines fault, and 4.9-24.8 cm on the Quien Sabe fault. Creep at depth appears to mimic the behaviors seen of creep on the surface in that evidence of steady slip, triggered slip, and episodic slip phenomena are also observed in the RE sequences. For comparison, we investigate the occurrence of REs west of the San Andreas fault within the …

We have derived ambient black carbon (BC) concentrations and estimated emission factors for on-road diesel vehicles from archived Coefficient of Haze (COH) data that was routinely collected beginning in 1967 at 11 locations in the San Francisco Bay Area. COH values are a measure of the attenuation of light by particles collected on a white filter, and available data indicate they are proportional to BC concentrations measured using the conventional aethalometer. Monthly averaged BC concentrations are up to five times greater in winter than summer, and, consequently, so is the population?s exposure to BC. The seasonal cycle in BC concentrations is similar for all Bay Area sites, most likely due to area-wide decreased pollutant dispersion during wintertime. A strong weekly cycle is also evident, with weekend concentrations significantly lower than weekday concentrations, consistent with decreased diesel traffic volume on weekends. The weekly cycle suggests that, in the Bay Area, diesel vehicle emissions are the dominant source of BC aerosol. Despite the continuous increase in diesel fuel consumption in California, annual Bay Area average BC concentrations decreased by a factor of ~;;3 from the late 1960s to the early 2000s. Based on estimated annual BC concentrations, on-road diesel fuel consumption, and …

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The amount of tritium remaining within and the release rate out of stainless steel process waste from the 232-F Tritium Facility at SRS is calculated as a function of time using the historical exposure of pipe during operation of the facility (1955-1958) and its subsequent deactivation and lay-up. The solution and diffusion of tritium in the wall is the mechanism that governs both the tritium contamination of the pipe during operation and its gradual release after deactivation, including radioactive decay while in the metal. This analysis applies to Segment 6 of the so-called Components in Grout waste form. Results of these calculations will be used in the Groundwater Transport assessment, part of the analysis of the Components in Grout.

Most expert analyses of the projected world energy needs show utilization of nuclear energy will be essential for the next few decades, and hence the need to support this technology grows. But as one measure of the supporting science base of this field, as of December 2006, only 25 Pu containing structures were in the Cambridge Structural Database, as compared to 21,807 for Fe. A comparison of the rate of addition to this knowledge base reveals that approximately 500 Fe structures are registered with the Cambridge Structural Database every year, while in the same period only two or three Pu crystal structures are published. A continuing objective of this laboratory has been the development of new sequestering agents for actinide decorporation and selective extractions. This effort has been based on similarities in the properties of Pu(IV) and Fe(III), and the chelating groups in microbial Fe(III) sequestering agents, siderophores. The HOPO ligands (Figure 1) are one such class of chelating group which have been investigated as selective actinide extractants.

New and recent results are presented on charm and charmonium spectroscopy from BABAR experiment at SLAC. In particular, measurements on D{sub sJ} states branching fractions have been performed both in B-decays and inclusive e{sup +}e{sup -} {yields} c{bar c} interactions. Here a search for D{sub sj}(2632) has been performed and a new D{sub sJ} state at a mass of 2.856 GeV/c{sup 2} has been observed. A search for Y(4260) has been performed in exclusive D{sub D} production from initial-state radiation.

This report describes the Dalitz plot analysis of D0 events constructed for the hydronic decay.

Observational evidence exists that winds of massive stars are clumped. Many massive star systems are known as non-thermal particle production sites, as indicated by their synchrotron emission in the radio band. As a consequence they are also considered as candidate sites for non-thermal high-energy photon production up to gamma-ray energies. The present work considers the effects of wind clumpiness expected on the emitting relativistic particle spectrum in colliding wind systems, built up from the pool of thermal wind particles through diffusive particle acceleration, and taking into account inverse Compton and synchrotron losses. In comparison to a homogeneous wind, a clumpy wind causes flux variations of the emitting particle spectrum when the clump enters the wind collision region. It is found that the spectral features associated with this variability moves temporally from low to high energy bands with the time shift between any two spectral bands being dependent on clump size, filling factor, and the energy-dependence of particle energy gains and losses.

Challenges associated with the materials that remain in spent fuel storage pools are emerging as countries deal with issues related to storing and cleaning up nuclear fuel left over from weapons production. The K Basins at the Department of Energy's site at Hanford in southeastern Washington State are an example. Years of corrosion products and piles of discarded debris are intermingled in the bottom of these two pools that stored more 2,100 metric tons (2,300 tons) of spent fuel. Difficult, costly projects are underway to remove radioactive material from the K Basins. Similar challenges exist at other locations around the globe. This paper compares the challenges of handling and treating radioactive sludge at several locations storing spent nuclear fuel.

Accelerators are the largest and most costly scientific instruments of the Department of Energy, with uses across a broad range of science, including colliders for particle physics and nuclear science and light sources and neutron sources for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation, is a broad, four-office (HEP, NP, BES, ASCR) effort to develop computational tools for the prediction and performance enhancement of accelerators. The tools being developed can be used to predict the dynamics of beams in the presence of optical elements and space charge forces, the calculation of electromagnetic modes and wake fields of cavities, the cooling induced by comoving beams, and the acceleration of beams by intense fields in plasmas generated by beams or lasers. In SciDAC-1, the computational tools had multiple successes in predicting the dynamics of beams and beam generation. In SciDAC-2 these tools will be petascale enabled to allow the inclusion of an unprecedented level of physics for detailed prediction.

In this lecture we presented a methodology to obtain free energies from empirical potentials and applied it to the study of the phase diagram of FeCr. Subsequently, we used Metropolis Monte Carlo to analyze homogeneous and heterogeneous precipitation of the Cr rich solid solution {alpha}{prime}. These examples are part of our work in the area of steels for nuclear applications and can be found in several publications of our group cited as References.