X-ray radiography is an important tool for diagnosing and imaging planar and convergent hydrodynamics phenomena for laser experiments. Until now, hydrodynamics experiments at Omega and NIF utilize E{sub x-ray} < 9 keV backlighter x-rays emitted by thermal plasmas. However, future experiments will need to diagnose larger and denser targets and will require x-ray probes of energies from 20-100 keV and possibly up to 1 MeV. Hard K-{alpha} x-ray photons can be created through high-energy electron interactions in the target material after irradiation by petawatt-class high-intensity-short-pulse lasers with > 10{sup 17} W/cm{sup 2}. We have performed several experiments on the JanUSP, and the Vulcan 100TW, and Vulcan Petawatt lasers to understand K-{alpha} sources and to test radiography concepts. 1-D radiography using an edge-on foil and 2-D radiography using buried wires and cone-fiber targets were tested. We find that 1-D thin edge-on foils can have imaging resolution better than 10 {micro}m. Micro volume targets produce bright sources with measured conversion efficiency from laser energy to x-ray photons of {approx} 1 x 10{sup -5}. This level of conversion may not be enough for 2-D point projection radiography. A comparison of our experimental measurements of small volume sources with the LSP/PIC simulation show similar …

Mitochondrial (mt) DNA sequences are used extensively to reconstruct evolutionary relationships among recently diverged animals,and have constituted the most widely used markers for species- and generic-level relationships for the last decade or more. However, most studies to date have employed relatively small portions of the mt-genome. In contrast, complete mt-genomes primarily have been used to investigate deep divergences, including several studies of the amount of mt sequence necessary to recover ancient relationships. We sequenced and analyzed 24 complete mt-genomes from a group of salamander species exhibiting divergences typical of those in many species-level studies. We present the first comprehensive investigation of the amount of mt sequence data necessary to consistently recover the mt-genome tree at this level, using parsimony and Bayesian methods. Both methods of phylogenetic analysis revealed extremely similar results. A surprising number of well supported, yet conflicting, relationships were found in trees based on fragments less than {approx}2000 nucleotides (nt), typical of the vast majority of the thousands of mt-based studies published to date. Large amounts of data (11,500+ nt) were necessary to consistently recover the whole mt-genome tree. Some relationships consistently were recovered with fragments of all sizes, but many nodes required the majority of the mt-genome …

Renewable energy sources, originating for the most part from the sun's radiant energy, are ubiquitous, long-lived, essentially free of carbon emissions, and have the potential to contribute significantly to mounting energy needs of the globe. In terms of percentage increase in installed capacity, renewable energy collectively is the fastest growing energy source. Even assuming that the developing world raises its standard of living considerably, the technical potential of renewable energies is more than enough to meet annual global needs several times over a century from now. Realizing even some of this potential involves overcoming obstacles in generation costs, proximity to markets, and in many cases intermittency, as well as others. From the perspective of work on a wide range of energy technologies by both the World Energy Council and the Intergovernmental Panel on Climate Change, the potential, timing, and investment costs for renewable energy technologies in the 21st century have become clearer. The marketplace, based on cost and performance, will determine which technologies are commercialized along with government policies that at a minimum do not hinder their introduction, and--at a maximum--may encourage more rapid and successful introduction. A wide range of possible scenarios (34) based on factors that include energy …

Yield functions and plastic potentials are expressed in terms of the invariants of the stress tensor for polycrystalline metals and other isotropic materials. The plastic volume change data of Richmond is used to evaluate the embedded materials properties for some bcc metals and one polymer. A general form for the plastic potential is found that is intended to represent and cover a wide range of materials types.

We present data on the soft (E{sub {gamma}} < 3-4 MeV) radiative strength function (RSF) for electromagnetic transitions between warm states (i.e. states several MeV above the yrast line) from two different types of experiments. The Oslo method provides data on the total level density and the sum (over all multipolarities) of all RSFs by sequential extraction from primary-{gamma} spectra. Measurements of two-step-decay spectra following neutron capture yields two-step-cascade (TSC) intensities which are roughly proportional to the product of two RSFs. Investigations on {sup 172}Yb and {sup 57}Fe have produced unexpected results. In the first case, a strong (B(M1 {up_arrow}) = 6.5 {mu}{sub N}{sup 2}) resonance at E = 3.3 MeV was identified. In the second case, a large (more than a factor of 10) enhancement compared to theoretical estimates of the very soft (E{sub {gamma}} {le} 3 MeV), summed RSF for transitions between warm states was observed. A somewhat weaker (factor {approx} 3) enhancement of the RSF in Mo isotopes observed within the Oslo method still awaits confirmation from TSC experiments.

We predict that coherent electromagnetic radiation in the 1-100 THz frequency range can be generated in crystalline materials when subject to a shock wave or soliton-like propagating excitation. To our knowledge, this phenomenon represents a fundamentally new form of coherent optical radiation source that is distinct from lasers and free-electron lasers. General analytical theory and molecular dynamics simulations demonstrate coherence lengths on the order of mm (around 20 THz) and potentially greater. The emission frequencies are determined by the shock speed and the lattice constants of the crystal and can potentially be used to determine atomic-scale properties of the shocked material.

The lateral organization and interactions of lipid and protein components within biological membranes are essential for their functions. Investigations of the lateral organization within membranes hinge upon the ability to differentiate one component of interest from another. Typically, fluorophores are conjugated to specific components, and the organization is probed with fluorescence microscopy. However, bulky fluorophores may change the physical properties of the components they label, only the labeled components can be visualized, and the diffraction limit of light restricts the lateral resolution. Here we present a method to image microdomains within supported lipid membranes using isotopic labels and high-resolution secondary ion mass spectrometry (SIMS) performed with the NanoSIMS 50 (Cameca). Lateral resolution of 100 nm is achieved with high sensitivity. Quantitative information on the lipid composition within each domain was determined using calibration curves constructed from homogeneous lipid bilayer samples that systematically varied in the isotopically labeled lipid content.

We report a preliminary branching fraction of (1.80 {+-} 0.37{sub stat.} {+-} 0.23{sub syst.}) x 10{sup -4} for the charmless exclusive semileptonic B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu} decay, where {ell} can be either a muon or an electron. This result is based on data corresponding to an integrated luminosity of 81 fb{sup -1} collected at the {Upsilon}(4S) resonance with the BABAR detector. The analysis uses B{bar B} events that are tagged by a B meson reconstructed in the semileptonic B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}(X) decays, where X can be either a {gamma} or a {pi}{sup 0} from a D* decay.

Measurements of radially resolved L-shell Mo spectra from wire array pinches on Sandia's Z generator are presented and analyzed using a collisional-radiative model. The spectra indicate large radial gradients in density over the {approx}8-mm-diameter plasma column, but only the emission from the {approx}2 mm central region of the pinch appears to be influenced by opacity. Population inversions and significant gain factors for 100-200 {angstrom} transitions in Ne-like Mo are predicted to exist at the diagnosed plasma conditions.

Liquid hydrogen targets have played a vital role in the physics program at SLAC for the past 40 years. These targets have ranged from small ''beer can'' targets to the 1.5 m long E158 target that was capable of absorbing up to 800 W without any significant density changes. Successful use of these targets has required the development of thin wall designs, liquid hydrogen pumps, remote positioning and alignment systems, safety systems, control and data acquisition systems, cryogenic cooling circuits and heat exchangers. Detailed operating procedures have been created to ensure safety and operational reliability. This paper surveys the evolution of liquid hydrogen targets at SLAC and discusses advances in several of the enabling technologies that made these targets possible.

We present new results on hadronic B and D decays from the BABAR experiment. The first part of this document presents searches for new channels which may be used for CP measurements. The second part is dedicated to hadronic decays with tests of QCD factorization predictions and other models for B structure and decay mechanisms. A new result on the reference branching ratio D{sub s}{sup +} {yields} {phi}{pi}{sup +} is also reported.

Gaussian basis functions, routinely employed in molecular electronic structure calculations, can be combined with numerical grid-based functions in a discrete variable representation to provide an efficient method for computing molecular continuum wave functions. This approach, combined with exterior complex scaling, obviates the need for slowly convergent single-center expansions, and allows one to study a variety of electron-molecule collision problems. The method is illustrated by computation of various bound and continuum properties of H2+.

Soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co L{sub 2,3} edge have been applied to explore the near-interfacial magnetism of Co electrodes in Co/alumina based magnetic tunnel junctions. By taking into account the formation of CoO at the FM/barrier interface, the change in the total magnetic moment on metallic Co atoms as a function of barrier oxidation has been determined. The results demonstrate a strong correlation between the Co moments and measured TMR values, and an enhancement in the Co moments for moderate oxidation times.

Large-scale eigenvalue problems arise in a number of DOE applications. This paper provides an overview of the recent development of eigenvalue computation in the context of two SciDAC applications. We emphasize the importance of Krylov subspace methods, and point out its limitations. We discuss the value of alternative approaches that are more amenable to the use of preconditioners, and report the progression using the multi-level algebraic sub-structuring techniques to speed up eigenvalue calculation. In addition to methods for linear eigenvalue problems, we also examine new approaches to solving two types of non-linear eigenvalue problems arising from SciDAC applications.

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Using a method originally proposed for describing a continuum-space polymer fluid, a new expression for the Helmholtz energy of mixing is proposed for a binary lattice mixture. Molecular size asymmetry and nonrandomness due to segment-segment interactions are taken into account. An expression proposed by Yan, Liu and Hu for a binary lattice mixture of monomers, based on the Ising model, is used as a reference system. Calculated critical constants and liquid-liquid coexistence curves are in good agreement with Monte Carlo simulations for lattice mixtures with modest size asymmetry. Because lattice spacing rises with increasing temperature, comparison of calculated binary liquid-liquid equilibria with experiment requires that calculations take into account that the interchange energy falls as temperature rises. While the new expression for the Helmholtz energy of mixing provides much improvement over the Flory-Huggins equation, calculated liquid-liquid equilibria for three binary systems are similar to those from Guggenheim's quasi-chemical theory.

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Electricity generated by distributed energy resources (DER) located close to end-use loads has the potential to meet consumer requirements more efficiently than the existing centralized grid. Installation of DER allows consumers to circumvent the costs associated with transmission congestion and other non-energy costs of electricity delivery and potentially to take advantage of market opportunities to purchase energy when attractive. On-site thermal power generation is typically less efficient than central station generation, but by avoiding non-fuel costs of grid power and utilizing combined heat and power (CHP) applications, i.e., recovering heat from small-scale on-site generation to displace fuel purchases, then DER can become attractive to a strictly cost-minimizing consumer. In previous efforts, the decisions facing typical commercial consumers have been addressed using a mixed-integer linear programme, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, and information (both technical and financial) on candidate DER technologies, DER-CAM minimizes the overall energy cost for a test year by selecting the units to install and determining their hourly operating schedules. In this paper, the capabilities of DER-CAM are enhanced by the inclusion of the option to store recovered low-grade heat. By being able to keep an inventory of heat …

This report was prepared to talk about Challenges of Investigating Fluid-Elastic Lock-In of a Shallow Cavity and a Cantilevered Beam at Low Mach Numbers

Article on energetics of the N-O bonds in 2-hydroxyphenazine-di-N-oxide.

Article discussing the stability studies of transition-metal linkage isomers using quantum mechanical methods and groups 11 and 12 transition metals.