In this short article the accurate labeling of the O4,5 edges of the light actinides is addressed. The O4 and O5 edges are both contained in what is termed the ''giant resonance'' and the smaller ''pre-peak'' that is observed is a consequence of first-order perturbation by the 5d spin-orbit interaction. Thus, the small prepeak in the actinide 5d {yields} 5f transition should not be labeled the O5 peak, but rather the {Delta}S=1 peak.

We summarize the status of the two U.S. feasibility studies carried out by the Neutrino Factory and Muon Collider Collaboration (NFMCC) along with recent improvements to Neutrino Factory design developed during the American Physical Society (APS) Neutrino Physics Study. Suggested accelerator topics for the International Scoping Study (ISS) are also indicated.

In order to study the molecular structure and dynamics of liquid water with soft x-ray probes, samples with nanoscale dimensions are needed. This paper describes a simple method for preparing nanofluidic water cells. The idea is to confine a thin layer of water between two silicon nitride windows. The windows are 1 mm x 1 mm and 0.5 mm x 0.5 mm in size and have a thickness of 150 nm. The thickness of the water layer was measured experimentally by probing the infrared spectrum of water in the cells with a Fourier Transform InfraRed (FTIR) apparatus and from soft x-ray static measurements at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. Water layers ranging from 10 nm to more than 2 {micro}m were observed. Evidence for changes in the water structure compared to bulk water is observed in the ultrathin cells.

Path Integral Monte Carlo (PIMC) can reproduce the results of simple analytical calculations in which a single quantum particle is used to represent positronium within an idealized, spherical pore. Our calculations improve on this approach by explicitly treating the positronium as a two-particle e{sup -}, e{sup +} system interacting via the Coulomb interaction. We study the lifetime and the internal contact density, {kappa}, which controls the self-annihilation behavior, for positronium in model spherical pores, as a function of temperature and pore size. We compare the results with both PIMC and analytical calculations for a single-particle model.

In real materials, nonlinear forces cause the frequencies of vibrating atoms to depend on amplitude. As a consequence, a large-amplitude fluctuation on the scale of the atom spacing can develop a frequency that does not resonate with the normal modes, causing energy to become trapped in an intrinsically localized mode (ILM)--also called 'discrete breather' or 'lattice soliton'. As temperature is increased, entropy is expected to stabilize increased concentrations of these random hotspots. This mechanism, which spontaneously concentrates energy, has been observed in analogous systems on a larger scale, but direct sightings at the atomic scale have proved difficult. Two challenges have hampered progress: (1) the need to separate ILMs from modes associated with crystal imperfections, and (2) complications that arise at high temperatures, including feature broadening and multiphonon processes. Here we solve both of these problems by actively creating ILMs at low temperatures in {alpha}-uranium using high-energy inelastic x-ray and neutron scattering. The ILM creation excitation occurs at energies ten times higher than conventional lattice excitations, cleanly separating it from modes associated with crystal imperfections. The discovery of this excitation not only proves the existence of ILMs in uranium but also opens up a new route for finding ILMs in …

For many rocks of high economic interest such as chalk,diatomite, tight gas sands or coal, nanometer scale resolution is neededto resolve the 3D-pore structure, which controls the flow and trapping offluids in the rocks. Such resolutions cannot be achieved with existingtomographic technologies. A new 3D imaging method, based on serialsectioning and using the Focused Ion Beam (FIB) technology has beendeveloped. FIB allows for the milling of layers as thin as 10 nanometersby using accelerated Ga+ ions to sputter atoms from the sample surface.After each milling step, as a new surface is exposed, a 2D image of thissurface is generated. Next, the 2D images are stacked to reconstruct the3D pore or grain structure. Resolutions as high as 10 nm are achievableusing this technique. A new image processing method uses directmorphological analysis of the pore space to characterize thepetrophysical properties of diverse formations. In addition to estimationof the petrophysical properties (porosity, permeability, relativepermeability and capillary pressures), the method is used for simulationof fluid displacement processes, such as those encountered in variousimproved oil recovery (IOR) approaches. Computed with the new methodcapillary pressure curves are in good agreement with laboratory data. Themethod has also been applied for visualization of the fluid distributionat various saturations …

The impact of three-dimensional subsurface heterogeneity on hillslope runoff generated by excess infiltration (so called Hortonian runoff) is examined. A fully-coupled, parallel subsurface overland flow model is used to simulate runoff from an idealized hillslope. Ensembles of correlated, Gaussian random fields of saturated hydraulic conductivity are used to create uncertainty and variability (i.e. structure) due to subsurface heterogeneity. A large number of cases are simulated in a parametric manner with variance of the hydraulic conductivity varied over two orders of magnitude. These cases include rainfall rates above, equal and below the geometric mean of the hydraulic conductivity distribution. These cases are also compared to theoretical considerations of runoff production based on simple assumptions regarding (1) the rainfall rate and the value of hydraulic conductivity in the surface cell using a spatially-indiscriminant approach; and (2) a percolation-theory type approach to incorporate so-called runon. Simulations to test the ergodicity of hydraulic conductivity on hillslope runoff are also performed. Results show three-dimensional features (particularly in the vertical dimension) in the hydraulic conductivity distributions that create shallow perching, which has an important effect on runoff behavior that is fundamentally different in character than previous two dimensional analyses. The simple theories are shown to be …

Experimental data indicates that the limiting crack speed in brittle materials is less than the Rayleigh wave speed. One reason for this is that dynamic instabilities produce surface roughness and microcracks that branch from the main crack. These processes increase dissipation near the crack tip over a range of crack speeds. When the scale of observation (or mesh resolution) becomes much larger than the typical sizes of these features, effective-medium theories are required to predict the coarse-grained fracture dynamics. Two approaches to modeling these phenomena are described and used in numerical simulations. The first approach is based on cohesive elements that utilize a rate-dependent weakening law for the nodal cohesive forces. The second approach uses a continuum damage model which has a weakening effect that lowers the effective Rayleigh wave speed in the material surrounding the crack tip. Simulations in this paper show that while both models are capable of increasing the energy dissipated during fracture when the mesh size is larger than the process zone size, only the continuum damage model is able to limit the crack speed over a range of applied loads. Numerical simulations of straight-running cracks demonstrate good agreement between the theoretical predictions of the combined …

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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 …

MSO is a good alternative to incineration for the treatment of a variety of organic wastes including obsolete explosives, low-level mixed waste streams, PCB contaminated oils, spent resins and carbon. The Lawrence Livermore National Laboratory (LLNL) has demonstrated the MSO process for the effective destruction of explosives, explosives-contaminated materials, and other wastes on a 1.5 kg/hr bench-scale unit and in an integrated MSO facility capable of treating 8 kg/hr of low-level radioactive mixed wastes. LLNL, under the direction and support of the Joint Demilitarization Technology (JDT) program, is currently building an integrated MSO plant for destroying explosives, explosives-contaminated sludge and explosives-contaminated activated charcoal. In a parallel effort, LLNL also provides technical support to DOE for the implementation of the MSO technology at industrial scale at Richland, Washington. Over 30 waste streams have been demonstrated with LLNL-built MSO systems. In this paper we will present our latest experimental data, our operational experience with MSO and also discuss its process capabilities.

Silica-filled polydimethylsiloxane (PDMS) composite systems find a broad range of applications due to their chemical and environmental resilience and the ability to fine tune, through chemical and processing modifications, the chemical and mechanical properties resulting in a precise engineering property for the final component. Thus, requirements for, and life-performance predictions of, these materials require an understanding of the interaction between the silica filler and the polymer network. Because silica surfaces are well known to have a high affinity for water adsorption, and this water is a critical part of the interface between the silica particles and the polymer matrix, water at this interface has important consequences on the nature of the silica-polymer bonding and subsequently the mechanical behaviour. Previous studies have reported on the water speciation and long-term outgassing kinetics of common fumed and precipitated silicas used in silicone elastomers, and of one such copolymer system in particular. Several different water species were observed to be present with a range of desorption activation energies. The amount and type of species present were observed to be dependent on the thermal and chemical history of the filler and the composite. Solid state Nuclear Magnetic Resonance (NMR) methods based on quantification of residual …

We propose undertaking a demonstration experiment on suppressing spontaneous undulator radiation from an electron beam at BNL's Accelerator Test Facility (ATF). We describe the method, the proposed layout, and a possible schedule. There are several advantages in strongly suppressing shot noise in the electron beam, and the corresponding spontaneous radiation. The self-amplified spontaneous (SASE) emission originating from shot noise in the electron beam is the main source of noise in high-gain FEL amplifiers. It may negatively affect several HG FEL applications ranging from single- to multi-stage HGHG FELs. SASE saturation also imposes a fundamental hard limit on the gain of an FEL amplifier in a coherent electron-cooling scheme. A novel active method for suppressing shot noise in relativistic electron beams by many orders-of-magnitude was recently proposed. While theoretically such strong suppression appears feasible, the performance and applicability of this novel method must be evaluated experimentally. Several practical questions about the proposed noise suppressor, such as 3D effects and/or sensitivity to the e-beam parameters also require experimental clarification. To do this, we propose here a proof-of-principle experiment using elements of the VISA FEL at BNL's Accelerator Test Facility.

Shot noise in the electron beam distribution is the main source of noise in high-gain FEL amplifiers, which may affect applications ranging from single- and multi-stage HGHG FELs to an FEL amplifier for coherent electron cooling. This noise also imposes a fundamental limit of about 10{sup 6} on FEL gain, after which SASE FELs saturate. There are several advantages in strongly suppressing this shot noise in the electron beam, and the corresponding spontaneous radiation. For more than a half-century, a traditional passive method has been used successfully in practical low-energy microwave electronic devices to suppress shot noise. Recently, it was proposed for this purpose in FELs. However, being passive, the method has some significant limitations and is hardly suitable for the highly inhomogeneous beams of modern high-gain FELs. I present a novel active method of suppressing, by many orders-of-magnitude, the shot noise in relativistic electron beams. I give a theoretical description of the process, and detail its fundamental limitation.

FEL-based coherent electron cooling (CEC) offers a new avenue to achieve high luminosities in high energy colliders such as RHIC, LHC, and eRHIC. Traditional treatments consider the FEL as an amplifier of optical waves with specific initial conditions, focusing on the resulting field. CEC requires knowledge of the phase space distribution of the electron beam in the FEL. We present 1D analytical results for the phase space distribution of an electron beam with an arbitrary initial current profile, and discuss approaches of expanding to 3D results.

Presented here is the complete genome sequence ofThiomicrospira crunogena XCL-2, representative of ubiquitouschemolithoautotrophic sulfur-oxidizing bacteria isolated from deep-seahydrothermal vents. This gammaproteobacterium has a single chromosome(2,427,734 bp), and its genome illustrates many of the adaptations thathave enabled it to thrive at vents globally. It has 14 methyl-acceptingchemotaxis protein genes, including four that may assist in positioningit in the redoxcline. A relative abundance of CDSs encoding regulatoryproteins likely control the expression of genes encoding carboxysomes,multiple dissolved inorganic nitrogen and phosphate transporters, as wellas a phosphonate operon, which provide this species with a variety ofoptions for acquiring these substrates from the environment. T. crunogenaXCL-2 is unusual among obligate sulfur oxidizing bacteria in relying onthe Sox system for the oxidation of reduced sulfur compounds. A 38 kbprophage is present, and a high level of prophage induction was observed,which may play a role in keeping competing populations of close relativesin check. The genome has characteristics consistent with an obligatelychemolithoautotrophic lifestyle, including few transporters predicted tohave organic allocrits, and Calvin-Benson-Bassham cycle CDSs scatteredthroughout the genome.

This paper summarizes the status of worldwide Neutrino Factory R&D efforts. Activities are categorized as simulations, component development, and system tests. An indication of R&D tasks that remain to be accomplished is also given.

We recently demonstrated the ability of semiconductor quantum dots to convert alpha radiation into visible photons. In this letter, we report on the scintillation of quantum dots under gamma-ray irradiation, and compare the energy resolution of the 59 keV line of Americium 241 obtained with our quantum dot-glass nanocomposite material to that of a standard sodium iodide scintillator. A factor 2 improvement is demonstrated experimentally and interpreted theoretically using a combination of energy-loss and photon transport models. These results demonstrate the potential of quantum dots for room-temperature gamma-ray detection, which has applications in medical imaging, environmental monitoring, as well as security and defense. Present technology in gamma radiation detection suffers from flexibility and scalability issues. For example, bulk Germanium provides fine energy resolution (0.2% energy resolution at 1.33 MeV) but requires operation at liquid nitrogen temperature. On the other hand, Cadmium-Zinc-Telluride is a good room temperature detector ( 1% at 662 keV) but the size of the crystals that can be grown is limited to a few centimeters in each direction. Finally, the most commonly used scintillator, Sodium Iodide (NaI), can be grown as large crystals but suffers from a lack of energy resolution (7% energy resolution at 662 keV). …

Complex metal hydrides have been synthesized for hydrogen storage through a new synthetic technique utilizing high hydrogen overpressure at elevated temperatures (molten state processing). This synthesis technique holds the potential of fusing different complex hydrides at elevated temperatures and pressures to form new species with enhanced hydrogen storage properties. Formation of these compounds is driven by thermodynamic and kinetic considerations. We report on investigations of the thermodynamics. Novel synthetic complexes were formed, structurally characterized, and their hydrogen desorption properties investigated. The effectiveness of the molten state process is compared with mechanicosynthetic ball milling.

X-ray fluorescence microCT (computed tomography) is a novel technique that allows non-destructive determination of the 3D distribution of chemical elements inside a sample. This is especially important in samples for which sectioning is undesirable either due to the risk of contamination or the requirement for further analysis by different characterization techniques. Developments made by third generation synchrotron facilities and laboratory X-ray focusing systems have made these kinds of measurements more attractive by significantly reducing scan times and beam size. First results from the x-ray fluorescence microCT experiments performed at SSRL beamline 6-2 are reported here. Beamline 6-2 is a 54 pole wiggler that uses a two mirror optical system for focusing the x-rays onto a virtual source slit which is then reimaged with a set of KB mirrors to a (2 x 4) {micro}{sup 2} beam spot. An energy dispersive fluorescence detector is located in plane at 90 degrees to the incident beam to reduce the scattering contribution. A PIN diode located behind the sample simultaneously measures the x-ray attenuation in the sample. Several porous micrometeorite samples were measured and the reconstructed element density distribution including self-absorption correction is presented. Ultimately, this system will be used to analyze particles from …

In-situ x-ray diffraction was used to study the response of single crystal iron under shock conditions. Measurements of the response of [001] iron showed a uniaxial compression of the initially bcc lattice along the shock direction by up to 6% at 13 GPa. Above this pressure, the lattice responded with a further collapse of the lattice by 15-18% and a transformation to a hcp structure. The in-situ measurements are discussed and results summarized.

The authors develop a plane-wave-based transfer matrix method in curvilinear coordinates to study the guided modes in curved nanoribbon waveguides. The problem of a curved structure is transformed into an equivalent one of a straight structure with spatially dependent tensors of dielectric constant and magnetic permeability. The authors investigate the coupling between the eigenmodes of the straight part and those of the curved part when the waveguide is bent. The authors show that curved sections can result in strong oscillations in the transmission spectrum similar to the recent experimental results of Lawet al.

Recent advances in the development and practical implementation of the Lattice-Boltzmann (LB) method as applied to computational fluid dynamics (CFD) have spurred much interest. A simple literature search of this area yielded well over 200 articles published in the open literature since 1997. The key advantage of the LB method is the time-accurate simulation of complex flow phenomena that are intractable with traditional methods. Analysis of flow in a parallel confined jet (PCJ) has been performed using the commercial LB-based CFD code PowerFLOW (Exa Corporation, Lexington, MA, USA). Results are compared to both experimental data and numerical results given in the literature, and it was observed that PowerFLOW does very well in accurately emulating the PJC experimental data as compared to Reynolds-Averaged Navier-Stokes schemes. In addition, the inherently transient nature of the LB method allowed the analysis of time-dependent aspects of jet flows (e.g., flapping).

Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, …