Calcium carbonate crystallization in organisms often occurs through the transformation from the amorphous precursor. It is believed that the amorphous phase could be temporarily stabilized and stored, until its templated transition to the crystalline form is induced. Here we develop a bio-inspired crystallization strategy that is based on the above mechanism. Amorphous calcium carbonate (ACC) spherulitic particles are formed and stabilized on a self-assembled monolayer (SAM) of hydroxy-terminated alkanethiols on Au surface. The ACC is stored as a reservoir for ions and is induced to crystallize on command by introducing a secondary surface that is functionalized with carboxylic acid-terminated SAM. This secondary surface acts as a template for oriented and patterned nucleation. Various oriented crystalline arrays and micropatterned films are formed. We also show that the ACC phase can be doped with foreign ions (e.g. Mg) and organic molecules (e.g. dyes) and that these dopants later function as growth modifiers of calcite crystals and become incorporated into the crystals during the transformation process of ACC to calcite. We believe that our strategy opens the way of using a stabilized amorphous phase as a versatile reservoir system that can be converted in a highly controlled fashion to a crystalline form upon …

The U.S. Department of Energy (DOE) is interested in developing tools and methods for use in designing and evaluating safeguards systems for current and future plants in the nuclear power fuel cycle. The DOE is engaging several DOE National Laboratories in efforts applied to safeguards for chemical conversion plants and gaseous centrifuge enrichment plants. As part of the development, Lawrence Livermore National Laboratory has developed an integrated safeguards system analysis tool (LISSAT). This tool provides modeling and analysis of facility and safeguards operations, generation of diversion paths, and evaluation of safeguards system effectiveness. The constituent elements of diversion scenarios, including material extraction and concealment measures, are structured using directed graphs (digraphs) and fault trees. Statistical analysis evaluates the effectiveness of measurement verification plans and randomly timed inspections. Time domain simulations analyze significant scenarios, especially those involving alternate time ordering of events or issues of timeliness. Such simulations can provide additional information to the fault tree analysis and can help identify the range of normal operations and, by extension, identify additional plant operational signatures of diversions. LISSAT analyses can be used to compare the diversion-detection probabilities for individual safeguards technologies and to inform overall strategy implementations for present and future plants. …

Laser ablation has proven to be an effective method for generating nanoparticles; particles are produced in the laser induced vapor plume during the cooling stage. To understand the in-situ condensation process, a series of time resolved light scattering images were recorded and analyzed. Significant changes in the condensation rate and the shape of the condensed aerosol plume were observed in two background gases, helium and argon. The primary particle shape and size distribution were measured using a transmission electron microscope (TEM), a scanning electron microscope (SEM) and a differential mobility analyzer (DMA). The gas dynamics simulation included nucleation and coagulation within the vapor plume, heat and mass transfer from the vapor plume to the background gas, and heat transfer to the sample. The experimental data and the calculated evolution of the shape of the vapor plume showed the same trend for the spatial distribution of the condensed particles in both background gases. The simulated particle size distribution also qualitatively agreed with the experimental data. It was determined that the laser energy, the physical properties of the background gas (conductivity, diffusivity and viscosity), and the shape of the ablation system (ablation chamber and the layout of the sample) have strong effects …

We currently use the CORSICA integrated modeling code for scenario studies for both the DIII-D and ITER experiments. In these simulations, free- or fixed-boundary equilibria are simultaneously converged with thermal evolution determined from transport models providing temperature and current density profiles. Using a combination of fixed boundary evolution followed by free-boundary calculation to determine the separatrix and coil currents. In the free-boundary calculation, we use the state-space controller representation with transport simulations to provide feedback modeling of shape, vertical stability and profile control. In addition to a tightly coupled calculation with simulator and controller imbedded inside CORSICA, we also use a remote procedure call interface to couple the CORSICA non-linear plasma simulations to the controller environments developed within the Mathworks Matlab/Simulink environment. We present transport simulations using full shape and vertical stability control with evolution of the temperature profiles to provide simulations of the ITER controller and plasma response.

The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The Velocity Interferometer System for Any Reflector (VISAR) measures shock velocities, shock breakout times, and emission of 1- to 5-mm targets at a location remote to the NIF target chamber. Three optical systems using the same vacuum chamber port each have a total track of 69 feet. All optical lenses are on kinematic mounts or sliding rails, enabling pointing accuracy of the optical axis to be checked. Counter-propagating laser beams (orange and red) align these diagnostics to a listing of tolerances. The orange alignment laser is introduced at the entrance to the two-level interferometer table and passes forward through the optical systems to the recording streak cameras. The red alignment laser is introduced in front of the recording streak cameras and passes in the reverse direction through all optical elements, out of the interferometer table, eventually reaching the target chamber center. Red laser wavelength is selected to be at the 50 percent reflection point of a special beamsplitter used to separate emission light from the Doppler-shifted interferometer light. Movable aperture cards, placed before and after lens groups, show the spread of alignments spots created …

Geologic storage of CO2 can be a viable technology forreducing atmospheric emissions of greenhouse gases only if it can bedemonstrated that leakage from proposed storage reservoirs and associatedhazards are small or can be mitigated. Risk assessment must evaluatepotential leakage scenarios and develop a rational, mechanisticunderstanding of CO2 behavior during leakage. Flow of CO2 may be subjectto positive feedbacks that could amplify leakage risks and hazards,placing a premium on identifying and avoiding adverse conditions andmechanisms. A scenario that is unfavorable in terms of leakage behavioris formation of a secondary CO2 accumulation at shallow depth. This paperdevelops a detailed numerical simulation model to investigate CO2discharge from a secondary accumulation, and evaluates the role ofdifferent thermodynamic and hydrogeologic conditions. Our simulationsdemonstrate self-enhancing as well as self-limiting feedbacks.Condensation of gaseous CO2, 3-phase flow of aqueous phase -- liquid CO2-- gaseous CO2, and cooling from Joule-Thomson expansion and boiling ofliquid CO2 are found to play important roles in the behavior of a CO2leakage system. We find no evidence that a subsurface accumulation of CO2at ambient temperatures could give rise to a high-energy discharge, aso-called "pneumatic eruption."

Mercuric iodide (HgI2) is a well known material for the direct detection of gamma rays; however, the largest volume achievable is limited by thickness of the detector, which needs to be a small fraction of the average trapping length for electrons. We are reporting here preliminary results in using HgI2 crystals to fabricate photocells used in the readout of various scintillators. The optical spectral response and efficiency of these photocells were measured and will be reported. Preliminary nuclear response from a HgI2 photocell that was optically matched to a Ce3+ :LaBr3 scintillator will also be presented and discussed. Further improvements will be sought by optimizing the transparent contact technology.

We present S/1 and R/1 test results on unconditioned and 355 nm (3{omega}), 500 ps laser conditioned DKDP. We find up to {approx}2.5X improvement in fluence in the S/1 performance after 3{omega}, 500 ps conditioning to 5 J/cm{sup 2}. For the first time, we observe a shift to higher fluences in the R/1 results for DKDP at 3{omega}, 7 ns due to 500 ps laser conditioning. The S/1 results are compared to {rho}({phi}) results previously measured on the same DKDP crystal [1]. A consistent behavior in fluence was found between the S/1 and {rho}({phi}) results for unconditioned and 500 ps conditioned DKDP. We were successful at using Poisson statistics to derive a connection between the S/1 and {rho}({phi}) results that could be tested with our data sets by trying to predict the shape of the {rho}({phi}) curve. The value for the power dependence on fluence of {rho}({phi}) derived from the S/1 data was {approx}11 {+-} 50%. The results presented and discussed here imply a strong correlation between the damage probability (S/1) test and {rho}({phi}). We find a consistent description of the two test types in terms of a power law {rho}({phi}) and that this basic shape held for all cases, …

3D cell cultures are rapidly becoming the method of choice for the physiologically relevant modeling of many aspects of non-malignant and malignant cell behavior ex vivo. Nevertheless, only a limited number of distinct cell types have been evaluated in this assay to date. Here we report the first large scale comparison of the transcriptional profiles and 3D cell culture phenotypes of a substantial panel of human breast cancer cell lines. Each cell line adopts a colony morphology of one of four main classes in 3D culture. These morphologies reflect, at least in part, the underlying gene expression profile and protein expression patterns of the cell lines, and distinct morphologies were also associated with tumor cell invasiveness and with cell lines originating from metastases. We further demonstrate that consistent differences in genes encoding signal transduction proteins emerge when even tumor cells are cultured in 3D microenvironments.

Consider the linear system Ax = b, where A is a large, sparse, real, symmetric, and positive definite matrix and b is a known vector. Solving this system for unknown vector x using a smoothed aggregation multigrid (SA) algorithm requires a characterization of the algebraically smooth error, meaning error that is poorly attenuated by the algorithm's relaxation process. For relaxation processes that are typically used in practice, algebraically smooth error corresponds to the near-nullspace of A. Therefore, having a good approximation to a minimal eigenvector is useful to characterize the algebraically smooth error when forming a linear SA solver. This paper discusses the details of a generalized eigensolver based on smoothed aggregation (GES-SA) that is designed to produce an approximation to a minimal eigenvector of A. GES-SA might be very useful as a standalone eigensolver for applications that desire an approximate minimal eigenvector, but the primary aim here is for GES-SA to produce an initial algebraically smooth component that may be used to either create a black-box SA solver or initiate the adaptive SA ({alpha}SA) process.

This paper will describe the use of a microchannel plate (MCP) as the associated particle detector on a sealed tube neutron generator. The generator produces neutrons and associated alpha particles for use as a probe to locate and identify hidden explosives in associated particle imaging (API). The MCP measures the position in two dimensions and precise timing of the incident alpha particle, information which is then used to calculate the emission time and direction of the corresponding neutron. The MCP replaces the position-sensitive photomultipler tube (PSPMT) which, until recently, had been the only detector available for measuring position and timing for alpha particles in neutron generator applications. Where the PSPMT uses charge division for generating position information, a process that requires a first order correction to each pulse, the MCP uses delay-line timing, which requires no correction. The result is a device with an order of magnitude improvement in both position resolution and timing compared to the PSPMT. Hardware and software development and the measurements made to characterize the MCP for API applications are described.

Plastic deformation has been observed in damascene Cu interconnect test structures during an in-situ electromigration experiment and before the onset of visible microstructural damage (ie. voiding) using a synchrotron technique of white beam X-ray microdiffraction. We show here that the extent of this electromigration-induced plasticity is dependent on the texture of the Cu grains in the line. In lines with strong <111> textures, the extent of plastic deformation is found to be relatively large compared to our plasticity results in the previous study [1] using another set of Cu lines with weaker textures. This is consistent with our earlier observation that the occurrence of plastic deformation in a given grain can be strongly correlated with the availability of a <112> direction of the crystal in the proximity of the direction of the electron flow in the line (within an angle of 10{sup o}). In <111> out-of-plane oriented grains in a damascene interconnect scheme, the crystal plane facing the sidewall tends to be a {l_brace}110{r_brace} plane,[2-4] so as to minimize interfacial energy. Therefore, it is deterministic rather than probabilistic that the <111> grains will have a <112> direction nearly parallel to the direction of electron flow. Thus, strong <111> textures lead …

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We describe a method for generating molecular hydrogen directly from the charge separation effected via rapid flow of liquid water through a metal orifice, wherein the input energy is the hydrostatic pressure times the volume flow rate. Both electrokinetic currents and hydrogen production rates are shown to follow simple equations derived from the overlap of the fluid velocity gradient and the anisotropic charge distribution resulting from selective adsorption of hydroxide ions to the nozzle surface. Pressure-driven fluid flow shears away the charge balancing hydronium ions from the diffuse double layer and carries them out of the aperture. Downstream neutralization of the excess protons at a grounded target electrode produces gaseous hydrogen molecules. The hydrogen production efficiency is currently very low (ca. 10-6) for a single cylindrical jet, but can be improved with design changes.

Funding for implementing risk handling strategies typically is allocated according to either the risk-averse approach (the worst risk first) or the cost-effective approach (the greatest risk reduction per implementation dollar first). This paper introduces a prime value approach in which risk handling strategies are prioritized according to how nearly they meet the goals of the organization that disburses funds for risk handling. The prime value approach factors in the importance of the project in which the risk has been identified, elements of both risk-averse and cost-effective approaches, and the time period in which the risk could happen. This paper also presents a prioritizer spreadsheet, which employs weighted criteria to calculate a relative rank for the handling strategy of each risk evaluated.

Microbes are the foundation for all of life. From the air we breathe to the soil we rely on for farming to the water we drink, everything humans need to survive is intimately coupled with the activities of microbes. Major advances have been made in the understanding of disease and the use of microorganisms in the industrial production of drugs, food products and wastewater treatment. However, our understanding of many complicated microbial environments (the gut and teeth), soil fertility, and biogeochemical cycles of the elements is lagging behind due to their enormous complexity. Inadequate technology and limited resources have stymied many lines of investigation. Today, most environmental microorganisms have yet to be isolated and identified, let alone rigorously studied. The American Academy of Microbiology convened a colloquium in Seattle, Washington, in February 2007, to deliberate the way forward in the study of microorganisms and microbial activities in the environment. Researchers in microbiology, marine science, pathobiology, evolutionary biology, medicine, engineering, and other fields discussed ways to build on and extend recent successes in microbiology. The participants made specific recommendations for targeting future research, improving methodologies and techniques, and enhancing training and collaboration in the field. Microbiology has made a great deal …

This paper describes two stylized alternative visions inpopular currencyof how the power system might evolve to meet futurerequirements for the high quality electricity service that modern digitaleconomies demand, a supergrids paradigm and a dispersed paradigm. Some ofthe economics of the dispersed vision are explored. Economic perspectivesare presented on both the choice of homogeneous universal power qualityupstream in the electricity supply, and also on the extremelyheterogeneous require-ments of end-use loads. Finally, the potential roleof microgrids in delivering heterogeneous power quality is demonstratedby reference to two ongoing microgrid tests in the U.S. andJapan.

The next generation of synchrotrons and free electron lasersrequires x-ray optical systems with extremely high-performance,generally, of diffraction limited quality. Fabrication and use of suchoptics requires highly accurate metrology. In the present paper, wediscuss a way to improve the performance of the Long Trace Profiler(LTP), a slope measuring instrument widely used at synchrotron facilitiesto characterize x-ray optics at high-spatial-wavelengths fromapproximately 2 mm to 1 m. One of the major sources of LTP systematicerror is the detector. For optimal functionality, the detector has topossess the smallest possible pixel size/spacing, a fast method ofshuttering, and minimal non-uniformity of pixel-to-pixel photoresponse.While the first two requirements are determined by choice of detector,the non-uniformity of photoresponse of typical detectors such as CCDcameras is around 2-3 percent. We describe a flat-field calibration setupspecially developed for calibration of CCD camera photo-response and darkcurrent with an accuracy of better than 0.5 percent. Such accuracy isadequate for use of a camera as a detector for an LTP with performance of~;0.1 microradian (rms). We also present the design details of thecalibration system and results of calibration of a DALSA CCD camera usedfor upgrading our LTP-II instrument at the ALS Optical MetrologyLaboratory.

Recently, the U.S. Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS’s requirements in terms of sensitivity, resolution, response time and reach back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron’s identiFINDER™, which primarily uses sodium iodide crystals (3.18-cm x 2.54-cm cylinders) as gamma detector, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack™ that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with …

The fully nonlinear 4D TEMPEST gyrokinetic continuum code produces frequency, collisionless damping of geodesic-acoustic mode (GAM) and zonal flow with fully nonlinear Boltzmann electrons for the inverse aspect ratio {epsilon}-scan and the tokamak safety factor q-scan in homogeneous plasmas. The TEMPEST simulation shows that GAM exists in edge plasma pedestal for steep density and temperature gradients, and an initial GAM relaxes to the standard neoclassical residual, rather than Rosenbluth-Hinton residual due to the presence of ion-ion collisions. The enhanced GAM damping explains experimental BES measurements on the edge q scaling of the GAM amplitude.

The Genomes On Line Database (GOLD) is a comprehensive resource of information for genome and metagenome projects world-wide. GOLD provides access to complete and ongoing projects and their associated metadata through pre-computed lists and a search page. The database currently incorporates information for more than 2900 sequencing projects, of which 639 have been completed and the data deposited in the public databases. GOLD is constantly expanding to provide metadata information related to the project and the organism and is compliant with the Minimum Information about a Genome Sequence (MIGS) specifications.

The development of third generation light sources like theAdvanced Light Source (ALS) or BESSY II brought to a focus the need forhigh performance synchrotron optics with unprecedented tolerances forslope error and micro roughness. Proposed beam lines at Free ElectronLasers (FEL) require optical elements up to a length of one meter,characterized by a residual slope error in the range of 0.1murad (rms),and rms values of 0.1 nm for micro roughness. These optical elements mustbe inspected by highly accurate measuring instruments, providing ameasurement uncertainty lower than the specified accuracy of the surfaceunder test. It is essential that metrology devices in use at synchrotronlaboratories be precisely characterized and calibrated to achieve thistarget. In this paper we discuss a proposal for a Universal Test Mirror(UTM) as a realization of a high performance calibration instrument. Theinstrument would provide an ideal calibration surface to replicate aredundant surface under test of redundant figure. The application of asophisticated calibration instrument will allow the elimination of themajority of the systematic error from the error budget of an individualmeasurement of a particular optical element. We present the limitationsof existing methods, initial UTM design considerations, possiblecalibration algorithms, and an estimation of the expectedaccuracy.

As part of an ongoing effort at Lawrence Livermore National Laboratory (LLNL) to enhance analytical models that simulate enrichment and conversion facilities, efforts are underway to develop routines to estimate the total gamma-ray flux and that of specific lines around process piping containing UF{sub 6}. The intent of the simulation modeling effort is to aid in the identification of possible areas where material diversion could occur, as input to an overall safeguards strategy. The operation of an enrichment facility for the production of low enriched uranium (LEU) presents certain proliferation concerns, including both the possibility of diversion of LEU and the potential for producing material enriched to higher-than-declared, weapons-usable levels. Safeguards applied by the International Atomic Energy Agency (IAEA) are designed to provide assurance against diversion or misuse. Among the measures being considered for use is the measurement of radiation fields at various locations in the cascade hall. Our prior efforts in this area have focused on developing a model to predict neutron fields and how they would change during diversion of misuse. The neutron models indicated that while neutron detection useful in monitoring feed and product containers, it was not useful for monitoring process lines. Our current effort is …

A velocimetry experiment has been designed to measure shock properties for small, cylindrical, metal targets (8 mm diameter × 2 mm thick). A target is accelerated by high explosives, caught, then retrieved for later inspection. The target is expected to move at a velocity of 0.1 to 3 km/sec. The complete experiment canister is ~105 mm in diameter and 380 mm long. Optical velocimetry diagnostics include the Velocity Interferometer System for Any Reflector (VISAR) and photon Doppler velocimetry (PDV). The packaging of the velocity diagnostics is not allowed to interfere with the foam catchment or an X-ray imaging diagnostic. Using commercial lenses, a single optical relay collects Doppler-shifted light for both VISAR and PDV. The use of fiber optics allows measurement of point velocities on the target surface for accelerations lasting for 3 mm of travel. Operating at 532 nm, the VISAR has separate illumination fibers requiring alignment. The PDV diagnostic operates at 1550 nm but is aligned and calibrated at 670 nm. VISAR and PDV diagnostics are complimentary measurements that image spots in close proximity on the target surface. Because the optical relay uses commercial glass, optical fibers’ axial positions are offset to compensate for chromatic aberrations. The optomechanical …