Linear-response (LR) theory in combination with the first-principles band structure codes allows to calculate phonons in an efficient way. In this report a formalism which enables us to apply LR theory within an all-electron framework utilizing the relativistic full-potential linearized augmented plane-wave (RFLAPW) method is presented. As first part, the equations for the calculations of the atomic forces are given and they are used for the calculation of forces in {alpha}-Pu. As a second step, a complete set of formulaes for the dynamic matrices calculation is presented.

The probability density function for wave propagating in a straight perfect electrical conductor (PEC) rough wall tunnel is deduced from the mathematical models of the random electromagnetic fields. The field propagating in caves or tunnels is a complex-valued Gaussian random processing by the Central Limit Theorem. The probability density function for single modal field amplitude in such structure is Ricean. Since both expected value and standard deviation of this field depend only on radial position, the probability density function, which gives what is the power distribution, is a radially dependent function. The radio channel places fundamental limitations on the performance of wireless communication systems in tunnels and caves. The transmission path between the transmitter and receiver can vary from a simple direct line of sight to one that is severely obstructed by rough walls and corners. Unlike wired channels that are stationary and predictable, radio channels can be extremely random and difficult to analyze. In fact, modeling the radio channel has historically been one of the more challenging parts of any radio system design; this is often done using statistical methods. In this contribution, we present the most important statistic property, the field probability density function, of wave propagating in …

We present a mathematical model describing the thermodynamic behavior of shape memory alloy wires, as well as a computational technique to solve the resulting system of partial differential equations. The model consists of conservation equations based on a new Helmholtz free energy potential. The computational technique introduces a viscosity-based continuation method, which allows the model to handle dynamic applications where the temporally local behavior of solutions is desired. Computational experiments document that this combination of modeling and solution techniques appropriately predicts the thermally- and stress-induced martensitic phase transitions, as well as the hysteretic behavior and production of latent heat associated with such materials.

We compare inexact Newton and coordinate descent methods for optimizing the quality of a mesh by repositioning the vertices, where quality is measured by the harmonic mean of the mean-ratio metric. The effects of problem size, element size heterogeneity, and various vertex displacement schemes on the performance of these algorithms are assessed for a series of tetrahedral meshes.

We report results from the third and final year of our project (ROA0101-35) to collect seismic event and waveform data recorded in and around the Arabian Peninsula. This effort involves several elements. We are working with King Abdulaziz City for Science and Technology to collect data from the Saudi National Seismic Network, that consists of 38 digital three-component stations (27 broadband and 11 short-period). We have an ongoing collaboration with the Kuwait Institute for Scientific Research, which runs the eight station Kuwait National Seismic Network. We installed two temporary broadband stations in the United Arab Emirates (funded by NNSA NA-24 Office of Non-Proliferation & International Security). In this paper we present a summary of data collected under these efforts including integration of the raw data into LLNL's Seismic Research Database and preliminary analysis of souce parameters and earth structure.

The ab initio No-Core Shell Model (NCSM) has recently been expanded to include nucleon-nucleon (NN) and three-nucleon (3N) interactions at the three-body cluster level. Here it is used to predict binding energies and spectra of p-shell nuclei based on realistic NN and 3N interactions. It is shown that 3N force (3NF) properties can be studied in these nuclear systems. First results show that interactions based on chiral perturbation theory lead to a realistic description of {sup 6}Li.

Lawrence Livermore National Laboratory (LLNL) conducted approximately 360 shots on Omega in FY04. Approximately half of the shots were devoted to ICF-relevant experiments. These are summarized as follows:

Fluid flow experiments are being conducted on core specimens of quartz monzonite retrieved from depths of about 1 km at the Desert Peak East EGS site in Churchill County, Nevada. Our immediate goal is to observe permeability evolution in fractures at pressure and temperature conditions appropriate to the Desert Peak geothermal site. Longer term, we aim to evaluate mechanisms that control the evolution of fracture permeability. In the experiments saline water is flowed through an artificial fracture at a constant rate of 0.02 ml/min over a period of several weeks. The constant flow tests are interrupted at selected times for shorter tests in which flow is either stopped or varied between 0 and 2.0 ml/min. The experiments to date were conducted at a confining pressure of 5.5 MPa, pore pressures of 1.38 MPa or 2.07 MPa and temperatures of 167- 169 C. Measurements include differential pressure and electrical resistance across the specimen. The short-term variable flow rate experiments allow us to calculate the effective hydraulic aperture of the fracture at various times during the experiment. Changes in electrical resistivity provide indirect evidence of ongoing mineral dissolution and precipitation processes that are expected to change fracture permeability over time. The early …

Laboratory measurements are required to establish relationships between the physical properties of unconsolidated sediments and P- and S-wave propagation through them. Previous work has either focused on measurements of compressional wave properties at depths greater than 500 m for oil industry applications or on measurements of dynamic shear properties at pressures corresponding to depths of less than 50 m for geotechnical applications. Therefore, the effects of lithology, fluid saturation, and compaction on impedance and P- and S-wave velocities of shallow soils are largely unknown. We describe two state-of-the-art laboratory experiments. One setup allows us to measure ultrasonic P-wave velocities at very low pressures in unconsolidated sediments (up to 0.1 MPa). The other experiment allows P- and S-wave velocity measurements at low to medium pressures (up to 20 MPa). We summarize the main velocity and attenuation results on sands and sand - clay mixtures under partially saturated and fully saturated conditions in two ranges of pressures (0 - 0.1 MPa and 0.1 - 20 MPa) representative of the top few meters and the top 1 km, respectively. Under hydrostatic pressures of 0.1 to 20 MPa, our measurements demonstrate a P- and S-wave velocity-dependence in dry sands around a fourth root (0.23 …

In the past 6 months, there has been increased interest in adding something analogous to C structs to the SIDL language and the Babel language interoperability tool [2, 6]. In particular, Rob Armstrong, of the Common Component Architecture [4], said the lack of structs ''is an oft-cited reason that people can't use Babel.'' Because the interest is high and lack of structs is a barrier to Babel adoption, we must carefully consider the current work around, the motivations for structs, the implications of adding structs, and the alternatives for structs in SIDL/Babel. This document provides the background necessary for a discussion of structs in SIDL/Babel. For the purposes of this document, I am going to call the potential new language feature a SIDL struct. The SIDL struct is analogous to a C struct, a Pascal record, or a Fortran 90 (F90) derived data type. It is a collection of data with no methods or behavior associated with it. Each element of the collection has a name and a type. SIDL structs allow for data abstraction, but they do not provide data hiding. All data is public in a SIDL struct.

The role of grain boundary constraint in strain localization and concomitant constitutive response was examined by performing a series of uniaxial compression tests on a tantalum bicrystal. Tantalum single crystals were diffusion bonded to form a (011) 90 twist boundary that was compressed along the common [011] direction. The plastic deformation resulted in the creation of deformation bands away from the highly constraining grain boundary, resembling those bands known from single crystal plastic deformation. Near the grain boundary, such deformation band formation could not be detected. Instead a distinctive pattern of crystal lattice rotation was observed that filled a rather large volume (several millimeters in size) around the bicrystal grain boundary. The internal deformation band structure as well as the crystal lattice rotation pattern near the bicrystal grain boundary were characterized and found to give greater rates of work hardening in the neighborhood of the grain boundary.

Livermore Computing is an early and aggressive adopter of parallel file systems including, for example, GPFS from IBM and Lustre for our present Linux systems. As such, we have acquired more than our share of battle scars from encountering bugs in 'bleeding edge' file systems that we have pressed into production to serve our customers' massive I/O requirements. A major role of the Scalable I/O Project is to detect errors before our end users do. In order to do this, we have developed highly parallel test codes to stress and probe potentially weak areas of file system behavior. This paper describes those test programs and how we make use of them.

In applications where jets propagate through energetic materials, they have been observed to become sufficiently perturbed to reduce their ability to effectively penetrate subsequent material. Analytical calculations of the jet Bernoulli flow provides an estimate of the onset and extent of such perturbations. Although two-dimensional calculations show the back-flow interaction pressure pulses, the symmetry dictates that the flow remains axial. In three dimensions the same pressure impulses can be asymmetrical if the jet is asymmetrical. The 3D calculations thus show parts of the jet having a significant component of radial velocity. On the average the downstream effects of this radial flow can be estimated and calculated by a 2D code by applying a symmetrical radial component to the jet at the appropriate position as the jet propagates through the energetic material. We have calculated the 3D propagation of a radio graphed TOW2 jet with measured variations in straightness and diameter. The resultant three-dimensional perturbations on the jet result in radial flow, which eventually tears apart the coherent jet flow. This calculated jet is compared with jet radiographs after passage through the energetic material for various material thickness and plate thicknesses. We noted that confinement due to a bounding metal plate …

The next generation of high-energy petawatt (HEPW)-class lasers will utilize multilayer dielectric diffraction gratings for pulse compression due to their high efficiency and high damage threshold for picosecond pulses. We have developed a short-pulse damage test station for accurate determination of the damage threshold of the optics used on future HEPW lasers. The design and performance of the damage test laser source, based on a highly stable, high-beam-quality optical parametric chirped-pulse amplifier, is presented. Our short-pulse damage measurement methodology and results are discussed. The damage initiation is attributed to multiphoton-induced avalanche ionization, strongly dependent on the electric field enhancement in the grating groove structure and surface defects. Measurement results of the dependence of damage threshold on the pulse width, angular dependence of damage threshold of diffraction gratings, and an investigation of short-pulse conditioning effects are presented. We report record >4 J/cm{sup 2} right section surface damage thresholds obtained on multilayer dielectric diffraction gratings at 76.5 incidence angles for 10-ps pulses.

Solid Phase Microextraction (SPME) has been used to sample nonnuclear materials for analysis by gas chromatography-mass spectrometry (GC/MS). This report summarizes progress in the areas of individual materials' outgassing signatures, microcompatibility tests and analysis of polar analytes.

The future of high-resolution ground-based optical and infrared astronomy requires the successful implementation of laser guide star adaptive optics systems. We present the first science results from the Lick Observatory sodium beacon laser guide star system. By coupling this system to a near-infrared (J;H;Ks bands) dual-channel imaging polarimeter, we achieve very high sensitivity to light scattered in the circumstellar enviroment of Herbig Ae/Be stars on scales of 100-300 AU. Observations of LkH{alpha} 198 reveal a highly polarized, biconical nebula 10 arcseconds in diameter (6000 AU) . We also observe a polarized jet-like feature associated with the deeply embedded source LkH{alpha} 198-IR. The star LkH{alpha} 233 presents a narrow, unpolarized dark lane dividing its characteristic butterfly-shaped polarized reflection nebulosity. This linear structure is oriented perpendicular to an optical jet and bipolar cavity and is consistent with the presence of an optically thick circumstellar disk blocking our direct view of the star. These data suggest that the evolutionary picture developed for the lower-mass T Tauri stars is also relevant to the Herbig Ae/Be stars and demonstrate the ability of laser guide star adaptive optics systems to obtain scientific results competitive with natural guide star adaptive optics or space-based telescopes.

The usual method for simulating die-castings consists of a solidification analysis of the casting process - a computer calculation of heat transfer between the casting and the die components. The use of cyclic simulations, coupled with the geometric accuracy of the finite element method, has advanced this procedure to the point where it is routinely used for reliable prediction of shrinkage defects in die-castings. Filling analysis is also routinely used to get a glimpse of cavity filling and ensures that overflows are at their most effective location. When coupled with heat transfer, a filling analysis is also very effective in demonstrating the effects of heat loss in the fluid and how it consequentially can negatively affect filling.

Effects of W on the creep resistance of two nearly fully lamellar TiAl alloys with 1.0 and 2.0 at.%W have been investigated. In the low stress regime (LS) a nearly quadratic (1.5<n<2) creep behavior was observed. It is found that the addition of W can improve the creep resistance; however, the addition of excess W can result in the formation of {beta} phase, which produces an adverse effect on the creep strength.

Dynamic equi-biaxial bulging of thin AerMet 100 alloy plates was studied. The plates were deformed using a gas-gun driven flyer plate test set-up at impact velocities between 1.0 and 2.0 km/sec. The results indicate that in addition to biaxial stretching (and thinning) of the plate, internal cavitation (spallation fracture) results from the complex wave interactions within the plate. No outward evidence of damage was observed at the lower velocities, in the range of 1.0-1.2 km/sec. Fine scale cracking of the plates was observed at impact velocity above approximately 1.4 km/sec. Complete specimen fracture, in the form of multiple petals and pie-shaped fragments, was observed at impact velocity above 1.6 km/sec. Hydrodynamic computer code simulations were performed, prior to and in conjunction with the experiments, to aid in experiment design and interpretation of the experimental data.

Interplanetary dust particles (IDPs) contain enigmatic sub-micron components called GEMS (Glass with Embedded Metal and Sulfides). The compositions and structures of GEMS indicate that they have been processed by exposure to ionizing radiation but details of the actual irradiation environment(s) have remained elusive. Here we propose a mechanism and astrophysical site for GEMS formation that explains for the first time the following key properties of GEMS; they are stoichiometrically enriched in oxygen and systematically depleted in S, Mg, Ca and Fe (relative to solar abundances), most have normal (solar) oxygen isotopic compositions, they exhibit a strikingly narrow size distribution (0.1-0.5 {micro}m diameter), and some of them contain ''relict'' crystals within their silicate glass matrices. We show that the compositions, size distribution, and survival of relict crystals are inconsistent with amorphization by particles accelerated by diffusive shock acceleration. Instead, we propose that GEMS are formed from crystalline grains that condense in stellar outflows from massive stars in OB associations, are accelerated in encounters with frequent supernova shocks inside the associated superbubble, and are implanted with atoms from the hot gas in the SB interior. We thus reverse the usual roles of target and projectile. Rather than being bombarded at rest by …

Exposure to environmental radiation and the application of new clinical modalities, such as radioimmunotherapy, have heightened the need to understand cellular responses to low dose and low-dose rate ionizing radiation. Many tumor cell lines have been observed to exhibit a hypersensitivity to radiation doses below 50 cGy, which manifests as a significant deviation from the clonogenic survival response predicted by a linear-quadratic fit to higher doses. However, the underlying processes for this phenomenon remain unclear. Using a gel microdrop/flow cytometry assay to monitor single cell proliferation at early times post irradiation, we examined the response of human A549 lung carcinoma, T98G glioma and MCF7 breast carcinoma cell lines exposed to gamma radiation doses from 0 to 200 cGy delivered at 0.18 and 22 cGy/min. The A549 and T98G cells, but not MCF7 cells, showed the marked hypersensitivity at doses <50 cGy. To further characterize the low-dose hypersensitivity, we examined the influence of low-dose radiation on cell cycle status and apoptosis by assays for active caspase-3 and phosphatidylserine translocation (annexin-V binding). We observed that caspase-3 activation and annexin-V binding mirrored the proliferation curves for the cell lines. Furthermore, the low-dose hypersensitivity and annexin-V binding to irradiated A549 and T98G cells were …

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A chemical ionization mass spectrometry (CIMS) technique has been developed for precise in situ measurements of hydrochloric acid (HCl) from a high-altitude aircraft. In measurements at subtropical latitudes, minimum HCl values found in the upper troposphere (UT) are often near or below the 0.005-ppbv detection limit of the measurements, indicating that background HCl values are much lower than a global mean estimate. However, significant abundances of HCl were observed in many UT air parcels as a result of stratosphere-to-troposphere transport events. A method for diagnosing the amount of stratospheric ozone in these UT parcels was developed using the compact linear correlation of HCl with ozone found throughout the lower stratosphere (LS). Expanded use of this method will lead to improved quantification of cross-tropopause transport events and validation of global chemical transport models.

Chiral two- and three-nucleon interactions are studied in a few-nucleon systems. We investigate the cut-off dependence and convergence with respect to the chiral expansion. It is pointed out that the spectra of light nuclei are sensitive to the three-nucleon force structure. As an example, we present calculations of the 1{sup +} and 3{sup +} states of {sup 6}Li using the no-core shell model approach. The results show contributions of the next-to-next-to-leading order terms to the spectra, which are not correlated to the three-nucleon binding energy prediction.