Article describes how the COVID-19 pandemic disrupted business services across all industries. In this study, the authors examine the impact during the first year of the COVID-19 pandemic on Texas museums, heritage sites, parks, and protected places with a focus on the evolving, and often conflicting, government policies.

Study examines the interaction between a key pathogenic HIV-1 viral protein, Nef, and ubiquitin (Ub)-protein ligase E3A (UBE3A).

This report describes development of processes for cladding APT Target tungsten components with a thin layer (0.127-mm) of Alloy 718, Alloy 600 or 316L stainless steel alloy. The application requires that the cladding be thermally bonded to the tungsten in order to transfer heat generated in the tungsten volume to a surrounding coolant. High temperature diffusion bonding using the hot isostatic processing (HIP) technique was selected as the method for creating a metallurgical bond between pure tungsten tubes and rods and the cladding materials. Bonding studies using a uniaxially loaded vacuum hot press were conducted in preliminary experiments to determine acceptable time-temperature conditions for diffusion bonding. The results were successfully applied in cladding tungsten rods and tubes with these alloys. Temperatures 800-810 C were suitable for cladding tungsten with Alloy 600 and 316L stainless steel alloy, whereas tungsten was clad with Alloy 718 at 1020 C.

We have undertaken an adaptive optics imaging survey of extrasolar planetary systems and stars showing interesting radial velocity trends from high precision radial velocity searches. Adaptive Optics increases the resolution and dynamic range of an image, substantially improving the detectability of faint close companions. This survey is sensitive to objects less luminous than the bottom of the main sequence at separations as close as 1 inch. We have detected stellar companions to the planet bearing stars HD 114762 and Tau Boo. We have also detected a companion to the non-planet bearing star 16 Cyg A.

Volume rendering converts a scalar function on a 3D volume into varying colors and opacities, and creates an image by integrating the color and opacity effects along viewing rays through each pixel [1]. For data specified on a regular grid, the ray tracing is straightforward [2,3,4,5], and similar effects can be obtained with 3D textures [6]. For curvilinear or irregular grids, these methods are only applicable after the data has been resampled. An alternative, which works directly on these more general grids, is cell projection [7,8,9]. The cells composited onto the image in back to front sorted order. The projections of the edges of a single cell divide the image plane into polygons, which can be scan converted and composited by standard graphics hardware. In references [9,10,11], we assumed that the cells were polyhedra with planar faces. A curvilinear grid maps a rectangular grid onto a curved volume, for example to fit next to an airplane wing or ship hull, and quadrilateral faces may map to non-planar surfaces. Irregular grids are fitted to complex geometries, for example mechanical parts, and even initially flat faces may become non-planar as the grid elements deform, for example, in a car crash simulation. Non-planar …

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The limits of applicability of the standard model are considered. The theory is described from an experimenter's viewpoint, emphasizing the observables. The present experimental situation is summarized. The aspects of symmetry breaking, radiative corrections, scattering of neutrinos from hadrons, and neutrino-electron scattering are discussed. The discussion is meant to underscore the need for a really precise measurement of the Weinberg angle in the scattering mode. A proposed LAMPF experiment is then described which is meant to combine excellent statistical precision with the potential for low systematic uncertainty in order to make such a measurement. (LEW)

We assessed particle deposition and loss occurring in two alpha-air monitors: an Eberline Alpha-3 Continuous Air Monitor (CAM) and a working-area transuranic aerosol monitor (WOTAMS). We investigated the dependence of particle size on losses in the sampling inlets and the real-time alpha detector areas for both instruments. We determined the uniformity of particle deposition on the filter to ascertain the effectiveness of the detector and collection-filter configuration. Results indicate that particle losses are a strong function of particle size in the CAM unit, with a 44% loss occurring for 6-..mu..m-diameter aerosols and a 0.3% loss for 0.6-..mu..m-diameter aerosols. Losses in the WOTAMS were less than 1% for particle diameters in the 0.6-to-7 ..mu..m range.

Some common instruments found in the chemistry laboratory have analog chart recorder output as their primary data readout media. Data reduction from this medium is slow and relatively inaccurate. This paper describes how to interface a single LSI-11 microcomputer to PERKIN-ELMER models 603 and 303 Atomic Absorption Spectrophotometers.

We present a new hybrid algorithm based on Godunov's method for computing eigenvectors of symmetric tridiagonal matrices and Inverse Iteration, which we call the Godunov-Inverse Iteration Algorithm. We use eigenvectors computed according to Godunov's method as starting vectors in the Inverse Iteration, replacing any nonnumeric elements of the Godunov eigenvectors with random uniform numbers. We use the right-hand bounds of the Ritz intervals found by the bisection method as Inverse Iteration shifts, while staying within guaranteed error bounds. In most test cases convergence is reached after only one step of the iteration, producing error estimates that are as good as or superior to those produced by standard Inverse Iteration implementations.

The cylindrical Hall thruster features high ionization efficiency, quiet operation, and ion acceleration in a large volume-to-surface ratio channel with performance comparable with the state-of-the-art annular Hall thrusters. These characteristics were demonstrated in low and medium power ranges. Optimization of miniaturized cylindrical thrusters led to performance improvements in the 50-200W input power range, including plume narrowing, increased thruster efficiency, reliable discharge initiation, and stable operation.

Although the main picture of fission bamer physics was established some time ago many of the details still have to be settled. Consequently, the application to evaluation of crosssections of unmeasurable or exotic nuclides and their excited states is still in its early stages. In this paper I consider some of these details and explore the possibility of quantitative estimation of fission cross-sections

We have searched for strangelets in a triggered sample of 61 million central (top 4percent) Au+Au collisions at sqrt sNN = 200 GeV near beam rapidities at the STAR solenoidal tracker detector at the BNL Relativistic Heavy Ion Collider. We have sensitivity to metastable strangelets with lifetimes of order>_0.1 ns, in contrast to limits over ten times longer in BNL Alternating Gradient Synchrotron (AGS) studies and longer still at the CERN Super Proton Synchrotron (SPS). Upper limits of a few 10-6 to 10-7 per central Au+Au collision are set for strangelets with mass>~;;30 GeV/c2.

Methods for geophysical model assessment, in particuale thecomputation of model parameter resolution, indicate the value and thelimitations of time-lapse data in estimating reservoir flow properties. Atrajectory-based method for computing sensitivities provides an effectivemeans to compute model parameter resolutions. We examine the commonsituation in which water encroaches into a resrvoir from below, as due tothe upward movement of an oil-water contact. Using straight-forwardtechniques we find that, by inclusing reflections off the top and bottomof a reservoir tens of meters thick, we can infer reservoir permeabilitybased upon time-lapse data. We find that, for the caseof water influxfrom below, using multiple time-lapse 'snapshots' does not necessarilyimprove the resolution of reservoir permeability. An application totime-lapse data from the Norne field illustrates that we can resolve thepermeability near a producing well using reflections from threeinterfaces associated with the reservoir.

The use of HTS materials in high radiation environmentsrequires that the superconducting properties remain constant up to aradiation high dose. BSCCO-2223 samples from two manufacturers wereirradiated with 50 MeV protons at fluences of up to 5 x 1017 protons/cm2.The samples lost approximately 75 percent of their pre-irradiation Ic.This compares with Nb3Sn, which loses about 50 percent at the samedisplacements per atom.

The lateral order of poly(styrene-block-isoprene) copolymer(PS-b-PI) thin films is characterized by the emerging technique ofresonant soft X-ray scattering (RSOXS) at the carbon K edge and comparedto ordering in bulk samples of the same materials measured usingconventional small-angle X-ray scattering. We show resonance using theoryand experiment that the loss of scattering intensity expected with adecrease in sample volume in the case of thin films can be overcome bytuning X-rays to the pi* resonance of PS or PI. Using RSOXS, we study themicrophase ordering of cylinder- and phere-forming PS-b-PI thin films andcompare these results to position space data obtained by atomic forcemicroscopy. Our ability to examine large sample areas (~;9000 mu m2) byRSOXS enables unambiguous identification of the lateral lattice structurein the thin films. In the case of the sphere-forming copolymer thin film,where the spheres are hexagonally arranged, the average sphere-to-spherespacing is between the bulk (body-centered cubic) nearest neighbor andbulk unit cell spacings. In the case of the cylinder-forming copolymerthin film, the cylinder-to-cylinder spacing is within experimental errorof that obtained in the bulk.

Various combinations of reactor type and fuel composition have been characterized using principle components analysis (PCA) of the concentrations of 9 U and Pu isotopes in the 10 fuel as a function of burnup. The use of PCA allows the reduction of the 9-dimensional data (isotopic concentrations) into a 3-dimensional approximation, giving a visual representation of the changes in nuclear fuel composition with burnup. Real-world variation in the concentrations of {sup 234}U and {sup 236}U in the fresh (unirradiated) fuel was accounted for. The effects of reprocessing were also simulated. The results suggest that, 15 even after reprocessing, Pu isotopes can be used to determine both the type of reactor and the initial fuel composition with good discrimination. Finally, partial least squares discriminant analysis (PSLDA) was investigated as a substitute for PCA. Our results suggest that PLSDA is a better tool for this application where separation between known classes is most important.

Arrays of clustered, regularly spaced short palindromic repeats (CRISPR) are widespread in the genomes of many bacteria and almost all archaea. These arrays are composed of direct repeats sized 24-47 bp separated by similarly sized non-repetitive sequences (spacers). It was recently experimentally shown that CRISPR arrays, along with a group of associated proteins, confer resistance to phage. Following exposure to phage, bacteria integrate new spacer sequences that are derived from the phage genome. Acquisition of these spacers enables the bacterial cell to shutdown the phage attack, presumably by an RNA-interference-like mechanism. This progress discusses the structure and function of CRISPRs and the implications of his new antiviral mechanisms in bacteria.

In a previous publication, procedures were proposed for unambiguously extracting amplitudes for single and double ionization from a time-dependent wavepacket by effectively propagating for an infinite time following a radiation pulse. Here we demonstrate the accuracy and utility of those methods for describing two-photon single and one-photon double ionization of helium. In particular it is shown how narrow features corresponding to autoionizing states are easily resolved with these methods.

The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF) requested development of tooling for remote replacement of gaskets in mechanical Hanford connectors. The facility has compressed air supply, two master-slave manipulators (MSM's) and a lightweight robotic arm for operation of the remote tools. The Savannah River National Laboratory (SRNL) developed and tested multiple tools to perform the gasket replacement tasks. Separate pneumatic snap-ring removal tools that use the connector skirt as a reaction surface were developed for removal of the snap ring and spent gasket on both vertical and horizontal Hanford connectors. A pneumatic tool that clamps and centers on the jumper pipe ID was developed to simultaneously install the new gasket and snap ring. A pneumatic snap-ring-loading tool was developed that compresses the snap ring and places it in a groove in the installation tool. All of the tools are located on a custom work table with a pneumatic valve station that directs compressed air to the desired tool and vents the tools as needed. The entire system has been successfully tested using MSM's to manipulate the various tools. Deployment of the entire system is expected during FY08. The Hanford connector gasket replacement tooling has been successfully tested …

A screening and ranking framework (SRF) has been developedto evaluate potential geologic carbon dioxide (CO2) storage sites on thebasis of health, safety, and environmental (HSE) risk arising from CO2leakage. The approach is based on the assumption that CO2 leakage risk isdependent on three basic characteristics of a geologic CO2 storage site:(1) the potential for primary containment by the target formation; (2)the potential for secondary containment if the primary formation leaks;and (3) the potential for attenuation and dispersion of leaking CO2 ifthe primary formation leaks and secondary containment fails. Theframework is implemented in a spreadsheet in which users enter numericalscores representing expert opinions or published information along withestimates of uncertainty. Applications to three sites in Californiademonstrate the approach. Refinements and extensions are possible throughthe use of more detailed data or model results in place of propertyproxies.

Diamondoids, hydrocarbon molecules with cubic-diamond-cage structures, have unique properties with potential value for nanotechnology. The availability and ability to selectively functionalize this special class of nanodiamond materials opens new possibilities for surface-modification, for high-efficiency field emitters in molecular electronics, as seed crystals for diamond growth, or as robust mechanical coatings. The properties of self-assembled monolayers (SAMs) of diamondoids are thus of fundamental interest for a variety of emerging applications. This paper presents the effects of thiol substitution position and polymantane order on diamondoid SAMs on gold using near-edge X-ray absorption fine structure spectroscopy (NEXAFS) and X-ray photoelectron spectroscopy (XPS). A framework to determine both molecular tilt and twist through NEXAFS is presented and reveals highly ordered diamondoid SAMs, with the molecular orientation controlled by the thiol location. C 1s and S 2p binding energies are lower in adamantane thiol than alkane thiols on gold by 0.67 {+-} 0.05 eV and 0.16 {+-} 0.04 eV respectively. These binding energies vary with diamondoid monolayer structure and thiol substitution position, consistent with different amounts of steric strain and electronic interaction with the substrate. This work demonstrates control over the assembly, in particular the orientational and electronic structure, providing a flexible design of surface …

Laser induced damage in potassium dihydrogen phosphate (KDP) has previously been shown to depend significantly on pulse duration for 351-nm Gaussian pulses. In this work we studied the properties of damage initiated by 1053-nm temporally Gaussian pulses with 10ns and 3ns FWHM durations. Our results indicate that the number of damage sites induced by 1053-nm light scales with pulse duration ({tau}) as ({tau}{sub 1}/{tau}{sub 2}){sup 0.17} in contrast to the previously reported results for 351-nm light as ({tau}{sub 1}/{tau}{sub 2}){sup 0.35}. This indicates that damage site formation is significantly less probable at longer wavelengths for a given fluence.