Science.gov

Sample records for dense shapes ldrd

  1. Laser Wire Deposition (WireFeed) for Fully Dense Shapes LDRD

    SciTech Connect

    GRIFFITH,MICHELLE L.; ENSZ,MARK T.; GREENE,DONALD L.; RECKAWAY,DARYL E.; MORIN,JACOB A.; BUCHHEIT,THOMAS E.; LAVAN,DAVID A.; CRENSHAW,THOMAS B.; TIKARE,VEENA; ROMERO,JOSEPH A.

    1999-11-01

    Direct metal deposition technologies produce complex, near net shape components from Computer Aided Design (CAD) solid models. Most of these techniques fabricate a component by melting powder in a laser weld pool, rastering the weld bead to form a layer, and additively constructing subsequent layers. This report will describe anew direct metal deposition process, known as WireFeed, whereby a small diameter wire is used instead of powder as the feed material to fabricate components. Currently, parts are being fabricated from stainless steel alloys. Microscopy studies show the WireFeed parts to be filly dense with fine microstructural features. Mechanical tests show stainless steel parts to have high strength values with retained ductility. A model was developed to simulate the microstructural evolution and coarsening during the WireFeed process. Simulations demonstrate the importance of knowing the temperature distribution during fabrication of a WireFeed part. The temperature distribution influences microstructural evolution and, therefore, must be controlled to tailor the microstructure for optimal performance.

  2. Laser Spray Fabrication for Net-Shape Rapid Product Realization LDRD

    SciTech Connect

    Atwood, C.L.; Ensz, M.T.; Greene, D.L.; Griffith, M.L.; Harwell, L.D.; Jeantette, F.P.; Keicher, D.M.; Oliver, M.S.; Reckaway, D.E.; Romero, J.A.; Schlienger, M.E.; Smugeresky, J.D.

    1999-04-01

    The primary purpose of this LDRD project was to characterize the laser deposition process and determine the feasibility of fabricating complex near-net shapes directly from a CAD solid model. Process characterization provided direction in developing a system to fabricate complex shapes directly from a CAD solid model. Our goal for this LDRD was to develop a system that is robust and provides a significant advancement to existing technologies (e.g., polymeric-based rapid prototyping, laser welding). Development of the process will allow design engineers to produce functional models of their designs directly from CAD files. The turnaround time for complex geometrical shaped parts will be hours instead of days and days instead of months. With reduced turnaround time, more time can be spent on the product-design phase to ensure that the best component design is achieved. Maturation of this technology will revolutionize the way the world produces structural components.

  3. Understanding shape entropy through local dense packing

    PubMed Central

    van Anders, Greg; Klotsa, Daphne; Ahmed, N. Khalid; Engel, Michael; Glotzer, Sharon C.

    2014-01-01

    Entropy drives the phase behavior of colloids ranging from dense suspensions of hard spheres or rods to dilute suspensions of hard spheres and depletants. Entropic ordering of anisotropic shapes into complex crystals, liquid crystals, and even quasicrystals was demonstrated recently in computer simulations and experiments. The ordering of shapes appears to arise from the emergence of directional entropic forces (DEFs) that align neighboring particles, but these forces have been neither rigorously defined nor quantified in generic systems. Here, we show quantitatively that shape drives the phase behavior of systems of anisotropic particles upon crowding through DEFs. We define DEFs in generic systems and compute them for several hard particle systems. We show they are on the order of a few times the thermal energy (kBT) at the onset of ordering, placing DEFs on par with traditional depletion, van der Waals, and other intrinsic interactions. In experimental systems with these other interactions, we provide direct quantitative evidence that entropic effects of shape also contribute to self-assembly. We use DEFs to draw a distinction between self-assembly and packing behavior. We show that the mechanism that generates directional entropic forces is the maximization of entropy by optimizing local particle packing. We show that this mechanism occurs in a wide class of systems and we treat, in a unified way, the entropy-driven phase behavior of arbitrary shapes, incorporating the well-known works of Kirkwood, Onsager, and Asakura and Oosawa. PMID:25344532

  4. Understanding shape entropy through local dense packing.

    PubMed

    van Anders, Greg; Klotsa, Daphne; Ahmed, N Khalid; Engel, Michael; Glotzer, Sharon C

    2014-11-11

    Entropy drives the phase behavior of colloids ranging from dense suspensions of hard spheres or rods to dilute suspensions of hard spheres and depletants. Entropic ordering of anisotropic shapes into complex crystals, liquid crystals, and even quasicrystals was demonstrated recently in computer simulations and experiments. The ordering of shapes appears to arise from the emergence of directional entropic forces (DEFs) that align neighboring particles, but these forces have been neither rigorously defined nor quantified in generic systems. Here, we show quantitatively that shape drives the phase behavior of systems of anisotropic particles upon crowding through DEFs. We define DEFs in generic systems and compute them for several hard particle systems. We show they are on the order of a few times the thermal energy ([Formula: see text]) at the onset of ordering, placing DEFs on par with traditional depletion, van der Waals, and other intrinsic interactions. In experimental systems with these other interactions, we provide direct quantitative evidence that entropic effects of shape also contribute to self-assembly. We use DEFs to draw a distinction between self-assembly and packing behavior. We show that the mechanism that generates directional entropic forces is the maximization of entropy by optimizing local particle packing. We show that this mechanism occurs in a wide class of systems and we treat, in a unified way, the entropy-driven phase behavior of arbitrary shapes, incorporating the well-known works of Kirkwood, Onsager, and Asakura and Oosawa. PMID:25344532

  5. Simulations of the interaction of intense petawatt laser pulses with dense Z-pinch plasmas : final report LDRD 39670.

    SciTech Connect

    Welch, Dale Robert; MacFarlane, Joseph John; Mehlhorn, Thomas Alan; Campbell, Robert B.

    2004-11-01

    We have studied the feasibility of using the 3D fully electromagnetic implicit hybrid particle code LSP (Large Scale Plasma) to study laser plasma interactions with dense, compressed plasmas like those created with Z, and which might be created with the planned ZR. We have determined that with the proper additional physics and numerical algorithms developed during the LDRD period, LSP was transformed into a unique platform for studying such interactions. Its uniqueness stems from its ability to consider realistic compressed densities and low initial target temperatures (if required), an ability that conventional PIC codes do not possess. Through several test cases, validations, and applications to next generation machines described in this report, we have established the suitability of the code to look at fast ignition issues for ZR, as well as other high-density laser plasma interaction problems relevant to the HEDP program at Sandia (e.g. backlighting).

  6. Final Report LDRD 02-ERD-013 Dense Plasma Characterization by X-ray Thomson Scattering

    SciTech Connect

    Landen, O L; Glenzer, S H; Gregori, G; Pollaine, S M; Hammer, J H; Rogers, F; Meezan, N B; Chung, H; Lee, R W

    2005-02-11

    We have successfully demonstrated spectrally-resolved x-ray scattering in a variety of dense plasmas as a powerful new technique for providing microscopic dense plasma parameters unattainable by other means. The results have also been used to distinguish between ionization balance models. This has led to 10 published or to be published papers, 8 invited talks and significant interest from both internal and external experimental plasma physicists and the international statistical plasma physics theory community.

  7. Line shape modeling in warm and dense hydrogen plasmas

    NASA Astrophysics Data System (ADS)

    Ferri, S.; Calisti, A.; Mossé, C.; Talin, B.; Gigosos, M. A.; González, M. A.

    2007-05-01

    A study of hydrogen lines emitted in warm ( T˜1eV) and dense ( N≥1018cm -3) plasmas is presented. Under such plasma conditions, the electronic and the ionic contributions to the line width are comparable, and the general question related to a transition from impact to quasi-static broadening arises not only for the far wings but also for the core of spectral lines. The transition from impact to quasi-static broadening for electrons is analyzed by means of Frequency Fluctuation Model (FFM). In parallel, direct integration of the semi-classical evolution equation is performed using electron electric fields calculated by Molecular Dynamics (MD) simulations that permit one to correctly describe the emitter environment. New cross comparisons between benchmark MD simulations and FFM are carried out for electron broadening of the Balmer series lines, and, especially, for the Hα line, for which a few experiments in the warm and dense plasma regimes are available.

  8. Geodesic distances to landmarks for dense correspondence on ensembles of complex shapes.

    PubMed

    Datar, Manasi; Lyu, Ilwoo; Kim, SunHyung; Cates, Joshua; Styner, Martin A; Whitaker, Ross

    2013-01-01

    Establishing correspondence points across a set of biomedical shapes is an important technology for a variety of applications that rely on statistical analysis of individual subjects and populations. The inherent complexity (e.g. cortical surface shapes) and variability (e.g. cardiac chambers) evident in many biomedical shapes introduce significant challenges in finding a useful set of dense correspondences. Application specific strategies, such as registration of simplified (e.g. inflated or smoothed) surfaces or relying on manually placed landmarks, provide some improvement but suffer from limitations including increased computational complexity and ambiguity in landmark placement. This paper proposes a method for dense point correspondence on shape ensembles using geodesic distances to a priori landmarks as features. A novel set of numerical techniques for fast computation of geodesic distances to point sets is used to extract these features. The proposed method minimizes the ensemble entropy based on these features, resulting in isometry invariant correspondences in a very general, flexible framework. PMID:24579119

  9. Simulation studies of ion dynamic effects on dense plasma line shapes

    SciTech Connect

    Pollock, E.L.

    1986-12-01

    Computer simulations have been widely used in studying dense plasma properties including the local field properties important in spectral line broadening calculations. We will review here a more recent use of simulation, possibly less familiar to this audience, where the time dependent ionic microfield generated by computer simulation of a plasma is used directly as a time dependent external potential for the evolution of the electronic structure of an ion. This permits calculation of the dipole correlation function and thus line shapes with the inclusion of ion dynamic effects. 12 refs., 7 figs.

  10. 2007 LDRD ANNUAL REPORT

    SciTech Connect

    French, T

    2008-12-16

    I am pleased to present the fiscal year 2007 Laboratory Directed Research and Development (LDRD) annual report. This represents the first year that SRNL has been eligible for LDRD participation and our results to date demonstrate we are off to an excellent start. SRNL became a National Laboratory in 2004, and was designated the 'Corporate Laboratory' for the DOE Office of Environmental Management (EM) in 2006. As you will see, we have made great progress since these designations. The LDRD program is one of the tools SRNL is using to enable achievement of our strategic goals for the DOE. The LDRD program allows the laboratory to blend a strong basic science component into our applied technical portfolio. This blending of science with applied technology provides opportunities for our scientists to strengthen our capabilities and delivery. The LDRD program is vital to help SRNL attract and retain leading scientists and engineers who will help build SRNL's future and achieve DOE mission objectives. This program has stimulated our research staff creativity, while realizing benefits from their participation. This investment will yield long term dividends to the DOE in its Environmental Management, Energy, and National Security missions.

  11. Particle-in-cell modeling for MJ scale dense plasma focus with varied anode shape

    SciTech Connect

    Link, A. Halvorson, C. Schmidt, A.; Hagen, E. C.; Rose, D. V.; Welch, D. R.

    2014-12-15

    Megajoule scale dense plasma focus (DPF) Z-pinches with deuterium gas fill are compact devices capable of producing 10{sup 12} neutrons per shot but past predictive models of large-scale DPF have not included kinetic effects such as ion beam formation or anomalous resistivity. We report on progress of developing a predictive DPF model by extending our 2D axisymmetric collisional kinetic particle-in-cell (PIC) simulations from the 4 kJ, 200 kA LLNL DPF to 1 MJ, 2 MA Gemini DPF using the PIC code LSP. These new simulations incorporate electrodes, an external pulsed-power driver circuit, and model the plasma from insulator lift-off through the pinch phase. To accommodate the vast range of relevant spatial and temporal scales involved in the Gemini DPF within the available computational resources, the simulations were performed using a new hybrid fluid-to-kinetic model. This new approach allows single simulations to begin in an electron/ion fluid mode from insulator lift-off through the 5-6 μs run-down of the 50+ cm anode, then transition to a fully kinetic PIC description during the run-in phase, when the current sheath is 2-3 mm from the central axis of the anode. Simulations are advanced through the final pinch phase using an adaptive variable time-step to capture the fs and sub-mm scales of the kinetic instabilities involved in the ion beam formation and neutron production. Validation assessments are being performed using a variety of different anode shapes, comparing against experimental measurements of neutron yield, neutron anisotropy and ion beam production.

  12. Coupling and ionization effects on hydrogen spectral line shapes in dense plasmas

    NASA Astrophysics Data System (ADS)

    Calisti, A.; Bureyeva, L. A.; Lisitsa, V. S.; Shuvaev, D.; Talin, B.

    2007-06-01

    A study of hydrogen lines emitted in dense and low temperature plasmas is presented. Coupling and ionization effects in a transition from impact to quasi-static broadening for electrons are analyzed with the help of the Frequency Fluctuation Model (FFM). Electron broadening of Balmer series lines is studied for different densities and temperatures spanning a wide domain from impact to quasi-static limit. It is shown that electronic broadening makes a transition from impact to quasi-static limit depending on plasma conditions and principal quantum number. Even for the Balmer alpha line, at a density equals 1018 cm-3 and a temperature equals 1 eV, this transition occurs both in the wings and the core of the line.

  13. Terradynamically streamlined shapes in animals and robots enhance traversability through densely cluttered terrain.

    PubMed

    Li, Chen; Pullin, Andrew O; Haldane, Duncan W; Lam, Han K; Fearing, Ronald S; Full, Robert J

    2015-08-01

    Many animals, modern aircraft, and underwater vehicles use fusiform, streamlined body shapes that reduce fluid dynamic drag to achieve fast and effective locomotion in air and water. Similarly, numerous small terrestrial animals move through cluttered terrain where three-dimensional, multi-component obstacles like grass, shrubs, vines, and leaf litter also resist motion, but it is unknown whether their body shape plays a major role in traversal. Few ground vehicles or terrestrial robots have used body shape to more effectively traverse environments such as cluttered terrain. Here, we challenged forest-floor-dwelling discoid cockroaches (Blaberus discoidalis) possessing a thin, rounded body to traverse tall, narrowly spaced, vertical, grass-like compliant beams. Animals displayed high traversal performance (79 ± 12% probability and 3.4 ± 0.7 s time). Although we observed diverse obstacle traversal strategies, cockroaches primarily (48 ± 9% probability) used a novel roll maneuver, a form of natural parkour, allowing them to rapidly traverse obstacle gaps narrower than half their body width (2.0 ± 0.5 s traversal time). Reduction of body roundness by addition of artificial shells nearly inhibited roll maneuvers and decreased traversal performance. Inspired by this discovery, we added a thin, rounded exoskeletal shell to a legged robot with a nearly cuboidal body, common to many existing terrestrial robots. Without adding sensory feedback or changing the open-loop control, the rounded shell enabled the robot to traverse beam obstacles with gaps narrower than shell width via body roll. Such terradynamically 'streamlined' shapes can reduce terrain resistance and enhance traversability by assisting effective body reorientation via distributed mechanical feedback. Our findings highlight the need to consider body shape to improve robot mobility in real-world terrain often filled with clutter, and to develop better locomotor-ground contact models to understand

  14. Morphometry of anatomical shape complexes with dense deformations and sparse parameters

    PubMed Central

    Durrleman, Stanley; Prastawa, Marcel; Charon, Nicolas; Korenberg, Julie R.; Joshi, Sarang; Gerig, Guido; Trouvé, Alain

    2016-01-01

    We propose a generic method for the statistical analysis of collections of anatomical shape complexes, namely sets of surfaces that were previously segmented and labeled in a group of subjects. The method estimates an anatomical model, the template complex, that is representative of the population under study. Its shape reflects anatomical invariants within the dataset. In addition, the method automatically places control points near the most variable parts of the template complex. Vectors attached to these points are parameters of deformations of the ambient 3D space. These deformations warp the template to each subject’s complex in a way that preserves the organization of the anatomical structures. Multivariate statistical analysis is applied to these deformation parameters to test for group differences. Results of the statistical analysis are then expressed in terms of deformation patterns of the template complex, and can be visualized and interpreted. The user needs only to specify the topology of the template complex and the number of control points. The method then automatically estimates the shape of the template complex, the optimal position of control points and deformation parameters. The proposed approach is completely generic with respect to any type of application and well adapted to efficient use in clinical studies, in that it does not require point correspondence across surfaces and is robust to mesh imperfections such as holes, spikes, inconsistent orientation or irregular meshing. The approach is illustrated with a neuroimaging study of Down syndrome (DS). Results demonstrate that the complex of deep brain structures shows a statistically significant shape difference between control and DS subjects. The deformation-based modeling is able to classify subjects with very high specificity and sensitivity, thus showing important generalization capability even given a low sample size. We show that results remain significant even if the number of

  15. Morphometry of anatomical shape complexes with dense deformations and sparse parameters.

    PubMed

    Durrleman, Stanley; Prastawa, Marcel; Charon, Nicolas; Korenberg, Julie R; Joshi, Sarang; Gerig, Guido; Trouvé, Alain

    2014-11-01

    We propose a generic method for the statistical analysis of collections of anatomical shape complexes, namely sets of surfaces that were previously segmented and labeled in a group of subjects. The method estimates an anatomical model, the template complex, that is representative of the population under study. Its shape reflects anatomical invariants within the dataset. In addition, the method automatically places control points near the most variable parts of the template complex. Vectors attached to these points are parameters of deformations of the ambient 3D space. These deformations warp the template to each subject's complex in a way that preserves the organization of the anatomical structures. Multivariate statistical analysis is applied to these deformation parameters to test for group differences. Results of the statistical analysis are then expressed in terms of deformation patterns of the template complex, and can be visualized and interpreted. The user needs only to specify the topology of the template complex and the number of control points. The method then automatically estimates the shape of the template complex, the optimal position of control points and deformation parameters. The proposed approach is completely generic with respect to any type of application and well adapted to efficient use in clinical studies, in that it does not require point correspondence across surfaces and is robust to mesh imperfections such as holes, spikes, inconsistent orientation or irregular meshing. The approach is illustrated with a neuroimaging study of Down syndrome (DS). The results demonstrate that the complex of deep brain structures shows a statistically significant shape difference between control and DS subjects. The deformation-based modelingis able to classify subjects with very high specificity and sensitivity, thus showing important generalization capability even given a low sample size. We show that the results remain significant even if the number of

  16. Particle-In-Cell Modeling For MJ Dense Plasma Focus with Varied Anode Shape

    NASA Astrophysics Data System (ADS)

    Link, A.; Halvorson, C.; Schmidt, A.; Hagen, E. C.; Rose, D.; Welch, D.

    2014-10-01

    Megajoule scale dense plasma focus (DPF) Z-pinches with deuterium gas fill are compact devices capable of producing 1012 neutrons per shot but past predictive models of large-scale DPF have not included kinetic effects such as ion beam formation or anomalous resistivity. We report on progress of developing a predictive DPF model by extending our 2D axisymmetric collisional kinetic particle-in-cell (PIC) simulations to the 1 MJ, 2 MA Gemini DPF using the PIC code LSP. These new simulations incorporate electrodes, an external pulsed-power driver circuit, and model the plasma from insulator lift-off through the pinch phase. The simulations were performed using a new hybrid fluid-to-kinetic model transitioning from a fluid description to a fully kinetic PIC description during the run-in phase. Simulations are advanced through the final pinch phase using an adaptive variable time-step to capture the fs and sub-mm scales of the kinetic instabilities involved in the ion beam formation and neutron production. Results will be present on the predicted effects of different anode configurations. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (LLNL) under Contract DE-AC52-07NA27344 and supported by the Laboratory Directed Research and Development Program (11-ERD-063) and the Computing Grand Challenge program at LLNL. This work supported by Office of Defense Nuclear Nonproliferation Research and Development within U.S. Department of Energy's National Nuclear Security Administration.

  17. LDRD Annual Report FY2006

    SciTech Connect

    Sketchley, J A; Kotta, P; De Yoreo, J; Jackson, K; van Bibber, K

    2007-03-20

    The Laboratory Directed Research and Development (LDRD) Program, authorized by Congress in 1991 and administered by the Laboratory Science and Technology Office, is our primary means for pursuing innovative, long-term, high-risk, and potentially high-payoff research that supports the missions of the Laboratory, the Department of Energy, and National Nuclear Security Administration in national security, energy security, environmental management, bioscience and technology to improve human health, and breakthroughs in fundamental science and technology. The accomplishments described in this Annual Report demonstrate the strong alignment of the LDRD portfolio with these missions and contribute to the Laboratory's success in meeting its goals. The LDRD budget of $92 million for FY2006 sponsored 188 projects. These projects were selected through an extensive peer-review process to ensure the highest scientific quality and mission relevance. Each year, the number of deserving proposals far exceeds the funding available, making the selection a tough one indeed. Our ongoing investments in LDRD have reaped long-term rewards for the Laboratory and the nation. Many Laboratory programs trace their roots to research thrusts that began several years ago under LDRD sponsorship. In addition, many LDRD projects contribute to more than one mission area, leveraging the Laboratory's multidisciplinary team approach to science and technology. Safeguarding the nation from terrorist activity and the proliferation of weapons of mass destruction will be an enduring mission of this Laboratory, for which LDRD will continue to play a vital role. The LDRD Program is a success story. Our projects continue to win national recognition for excellence through prestigious awards, papers published in peer-reviewed journals, and patents granted. With its reputation for sponsoring innovative projects, the LDRD Program is also a major vehicle for attracting and retaining the best and the brightest

  18. LDRD final report : autotuning for scalable linear algebra.

    SciTech Connect

    Heroux, Michael Allen; Marker, Bryan

    2011-09-01

    This report summarizes the progress made as part of a one year lab-directed research and development (LDRD) project to fund the research efforts of Bryan Marker at the University of Texas at Austin. The goal of the project was to develop new techniques for automatically tuning the performance of dense linear algebra kernels. These kernels often represent the majority of computational time in an application. The primary outcome from this work is a demonstration of the value of model driven engineering as an approach to accurately predict and study performance trade-offs for dense linear algebra computations.

  19. Tiger LDRD final report

    SciTech Connect

    Steich, D J; Brugger, S T; Kallman, J S; White, D A

    2000-02-01

    This final report describes our efforts on the Three-Dimensional Massively Parallel CEM Technologies LDRD project (97-ERD-009). Significant need exists for more advanced time domain computational electromagnetics modeling. Bookkeeping details and modifying inflexible software constitute a vast majority of the effort required to address such needs. The required effort escalates rapidly as problem complexity increases. For example, hybrid meshes requiring hybrid numerics on massively parallel platforms (MPPs). This project attempts to alleviate the above limitations by investigating flexible abstractions for these numerical algorithms on MPPs using object-oriented methods, providing a programming environment insulating physics from bookkeeping. The three major design iterations during the project, known as TIGER-I to TIGER-III, are discussed. Each version of TIGER is briefly discussed along with lessons learned during the development and implementation. An Application Programming Interface (API) of the object-oriented interface for Tiger-III is included in three appendices. The three appendices contain the Utilities, Entity-Attribute, and Mesh libraries developed during the project. The API libraries represent a snapshot of our latest attempt at insulated the physics from the bookkeeping.

  20. SRNL LDRD ANNUAL REPORT 2008

    SciTech Connect

    French, T

    2008-12-29

    The Laboratory Director is pleased to have the opportunity to present the 2008 Laboratory Directed Research and Development (LDRD) annual report. This is my first opportunity to do so, and only the second such report that has been issued. As will be obvious, SRNL has built upon the excellent start that was made with the LDRD program last year, and researchers have broken new ground in some important areas. In reviewing the output of this program this year, it is clear that the researchers implemented their ideas with creativity, skill and enthusiasm. It is gratifying to see this level of participation, because the LDRD program remains a key part of meeting SRNL's and DOE's strategic goals, and helps lay a solid scientific foundation for SRNL as the premier applied science laboratory. I also believe that the LDRD program's results this year have demonstrated SRNL's value as the EM Corporate Laboratory, having advanced knowledge in a spectrum of areas, including reduction of the technical risks of cleanup, separations science, packaging and transportation of nuclear materials, and many others. The research in support of Energy Security and National and Homeland Security has been no less notable. SRNL' s researchers have shown again that the nascent LDRD program is a sound investment for DOE that will pay off handsomely for the nation as time goes on.

  1. LDRD FY 2014 Program Plan

    SciTech Connect

    Anita Gianotto; Dena Tomchak

    2013-08-01

    As required by DOE Order 413.2B the FY 2014 Program Plan is written to communicate ares of investment and approximate amounts being requested for the upcoming fiscal year. The program plan also includes brief highlights of current or previous LDRD projects that have an opportunity to impact our Nation's current and future energy challenges.

  2. Physical properties and formation of MCLD 126.6+24.5 : a dense cometary shape globule at high-Galactic latitude

    NASA Astrophysics Data System (ADS)

    Ristorcelli, Isabelle; Rivera-Ingraham, Alana; Juvela, Mika; Falgarone, Edith; Pelkonen, Veli-Matti; Pagani, Laurent; Ysard, Nathalie; Montier, Ludovic; Montillaud, Julien; Marshall, Douglas; Bernard, Jean-Philippe

    2015-08-01

    The high-latitude molecular clouds are mostly gravitationally unbound and an interesting question to be investigated is how dense cores can form in such tenuous, diffuse environment, and what is their ability to form stars. Are these dense cores forming from random fluctuations in a turbulent medium, or is their formation triggered by external mechanisms ?We present here a detailed analysis of the dense high-latitude clump MCLD 126.6+24.5 observed with PACS and SPIRE as part of the Herschel Key-Program ‘Galactic Cold Cores’, a follow-up of Planck detections. The clump lies in a tenuous high-latitude cloud, located at the border of the Polaris Flare, a large molecular cirrus cloud in the direction of the north celestial pole, at an estimated distance of 150 pc. Its cometary globule shape appears similar to what is usually found in globules in active star formation regions, although this nebula is far from any such region.The column density distribution derived from the Herschel data shows a very sharp edge and narrow transition between the diffuse medium and the molecular part of the cloud. This remarkable feature could be the signature of a shocked-compression flow from its southern side, likely associated with the North Celestial Pole HI loop. Cold cores are found embedded inside the globule, with temperatures down to 10K. We also analyse the properties of its 2 main filaments (including a pillar-like structure). We present their main characteristics, both in terms of dust and gas physical properties, combining the Herschel data with IRAM maps of 13CO and C18O. We compare the overall properties of the globule and its structure with predictions from MHD simulations in order to investigate the origin of this intriguing cometary shape globule found in high-galactic latitude diffuse environment.

  3. FY2014 LBNL LDRD Annual Report

    SciTech Connect

    Ho, Darren

    2015-06-01

    Laboratory (Berkeley Lab or LBNL) is a multi-program national research facility operated by the University of California for the Department of Energy (DOE). As an integral element of DOE’s National Laboratory System, Berkeley Lab supports DOE’s missions in fundamental science, energy resources, and environmental quality. Berkeley Lab programs advance four distinct goals for DOE and the nation. The LDRD program supports Berkeley Lab’s mission in many ways. First, because LDRD funds can be allocated within a relatively short time frame, Berkeley Lab researchers can support the mission of the Department of Energy (DOE) and serve the needs of the nation by quickly responding to forefront scientific problems. Second, LDRD enables Berkeley Lab to attract and retain highly qualified scientists and to support their efforts to carry out worldleading research. In addition, the LDRD program also supports new projects that involve graduate students and postdoctoral fellows, thus contributing to the education mission of Berkeley Lab.

  4. 2013 SRNL LDRD Annual Report

    SciTech Connect

    McWhorter, S.

    2014-03-07

    This report demonstrates the execution of our LDRD program within the objectives and guidelines outlined by the Department of Energy (DOE) through the DOE Order 413.2b. The projects described within the report align purposefully with SRNL’s strategic vision and provide great value to the DOE. The diversity exhibited in the research and development projects underscores the DOE Office of Environmental Management (DOE-EM) mission and enhances that mission by developing the technical capabilities and human capital necessary to support future DOE-EM national needs. As a multiprogram national laboratory, SRNL is applying those capabilities to achieve tangible results for the nation in National Security, Environmental Stewardship, Clean Energy and Nuclear Materials Management.

  5. Rheology of dense suspensions of shape anisotropic particles designed to show pH-sensitive anisotropic pair potentials

    NASA Astrophysics Data System (ADS)

    Jiang, Tianying; Zukoski, Charles F.

    2012-09-01

    Here we investigate the flow properties of suspensions of dicolloidal particles composed of interpenetrating spheres where one sphere is rich in polystyrene and the second is rich in poly 2-vinyl pyridine. The synthesis method is designed to create both anisotropic shape and anisotropic interaction potentials that should lead to head to tail clustering. These particles are referred to as copolymer dicolloids (CDCs). The viscoelastic properties of stable and gelled suspensions of CDC particles are compared with analogs composed of homopolymer dicolloids (HDCs), having the same shape but not displaying the anisotropic attractions. After coating the particles with a nonionic surfactant to minimize van der Waals attractions, the flow properties of glassy and gelled suspensions of CDCs and HDCs are studied as a function of volume fraction, ionic strength and pH. Suspensions of HDC particles display a high kinetic arrest volume fraction (ϕg > 0.5) over a wide range of pH and ionic strength up to [I]=0.5 M, demonstrating that the particles experience repulsive or weakly attractive pair potentials. Suspensions of CDC particles behave in a similar manner at high or low pH when [I]=0.001 M, but gel at a volume fraction of ϕg < 0.3 and display anomalously large elastic moduli at and above the gel transition point for intermediate pH or for pH=9 when [I]=0.5 M. The gelation processes for the CDC particles are reversible by adjusting the solution pH. Interaction potential anisotropy is evident in the processes, during which the CDC particles yield on increasing oscillatory strain.

  6. 1999 LDRD Laboratory Directed Research and Development

    SciTech Connect

    Rita Spencer; Kyle Wheeler

    2000-06-01

    This is the FY 1999 Progress Report for the Laboratory Directed Research and Development (LDRD) Program at Los Alamos National Laboratory. It gives an overview of the LDRD Program, summarizes work done on individual research projects, relates the projects to major Laboratory program sponsors, and provides an index to the principal investigators. Project summaries are grouped by their LDRD component: Competency Development, Program Development, and Individual Projects. Within each component, they are further grouped into nine technical categories: (1) materials science, (2) chemistry, (3) mathematics and computational science, (4) atomic, molecular, optical, and plasma physics, fluids, and particle beams, (5) engineering science, (6) instrumentation and diagnostics, (7) geoscience, space science, and astrophysics, (8) nuclear and particle physics, and (9) bioscience.

  7. FY 2014 LDRD Annual Report Project Summaries

    SciTech Connect

    Tomchak, Dena

    2015-02-01

    The FY 2014 Laboratory Directed Research and Development (LDRD) Annual Report is a compendium of the diverse research performed to develop and ensure the INL's technical capabilities can support future DOE missions and national research priorities. LDRD is essential to INL - it provides a means for the laboratory to pursue novel scientific and engineering research in areas that are deemed too basic or risky for programmatic investments. This research enahnces technical capabilities at the laboratory, providing scientific and engineering staff with opportunities for skill building and partnership development.

  8. Final LDRD report : advanced plastic scintillators for neutron detection.

    SciTech Connect

    Vance, Andrew L.; Mascarenhas, Nicholas; O'Bryan, Greg; Mrowka, Stanley

    2010-09-01

    This report summarizes the results of a one-year, feasibility-scale LDRD project that was conducted with the goal of developing new plastic scintillators capable of pulse shape discrimination (PSD) for neutron detection. Copolymers composed of matrix materials such as poly(methyl methacrylate) (PMMA) and blocks containing trans-stilbene (tSB) as the scintillator component were prepared and tested for gamma/neutron response. Block copolymer synthesis utilizing tSBMA proved unsuccessful so random copolymers containing up to 30% tSB were prepared. These copolymers were found to function as scintillators upon exposure to gamma radiation; however, they did not exhibit PSD when exposed to a neutron source. This project, while falling short of its ultimate goal, demonstrated the possible utility of single-component, undoped plastics as scintillators for applications that do not require PSD.

  9. Final report for LDRD project learning efficient hypermedia navigation

    SciTech Connect

    Chen, Pang; Laguna, G.

    1997-08-01

    This report documents the work performed under the Laboratory-Directed Research and Development (LDRD) grant {open_quotes}Learning Efficient Hypermedia Navigation.{close_quotes} The bulk of the work is contained in the software developed for the WWW and a copy of the software demonstrating its use has been submitted to the LDRD office.

  10. LDRD 149045 final report distinguishing documents.

    SciTech Connect

    Mitchell, Scott A.

    2010-09-01

    This LDRD 149045 final report describes work that Sandians Scott A. Mitchell, Randall Laviolette, Shawn Martin, Warren Davis, Cindy Philips and Danny Dunlavy performed in 2010. Prof. Afra Zomorodian provided insight. This was a small late-start LDRD. Several other ongoing efforts were leveraged, including the Networks Grand Challenge LDRD, and the Computational Topology CSRF project, and the some of the leveraged work is described here. We proposed a sentence mining technique that exploited both the distribution and the order of parts-of-speech (POS) in sentences in English language documents. The ultimate goal was to be able to discover 'call-to-action' framing documents hidden within a corpus of mostly expository documents, even if the documents were all on the same topic and used the same vocabulary. Using POS was novel. We also took a novel approach to analyzing POS. We used the hypothesis that English follows a dynamical system and the POS are trajectories from one state to another. We analyzed the sequences of POS using support vector machines and the cycles of POS using computational homology. We discovered that the POS were a very weak signal and did not support our hypothesis well. Our original goal appeared to be unobtainable with our original approach. We turned our attention to study an aspect of a more traditional approach to distinguishing documents. Latent Dirichlet Allocation (LDA) turns documents into bags-of-words then into mixture-model points. A distance function is used to cluster groups of points to discover relatedness between documents. We performed a geometric and algebraic analysis of the most popular distance functions and made some significant and surprising discoveries, described in a separate technical report.

  11. Processes for forming exoergic structures with the use of a plasma and for producing dense refractory bodies of arbitrary shape therefrom

    DOEpatents

    Holt, J. Birch; Kelly, Michael D.

    1990-01-01

    Plasma spraying methods of forming exoergic structures and coatings, as well as exoergic structures produced by such methods, are provided. The methods include the plasma spraying of reactive exoergic materials that are capable of sustaining a combustion synthesis reaction onto a flat substrate or into molds of arbitrary shape and igniting said plasma sprayed materials, either under an inert gas pressure or not, to form refractory materials of varying densities and of varying shapes.

  12. Final report on LDRD project : advanced optical trigger systems.

    SciTech Connect

    Roose, Lars D.; Hadley, G. Ronald; Mar, Alan; Serkland, Darwin Keith; Geib, Kent Martin; Sullivan, Charles Thomas; Keeler, Gordon Arthur; Bauer, Thomas M.; Peake, Gregory Merwin; Loubriel, Guillermo Manuel; Montano, Victoria A.

    2008-09-01

    are difficult to scale and manufacture with the required uniformity. As a promising alternative to multiple discrete edge-emitting lasers, a single wafer of vertical-cavity surface-emitting lasers (VCSELs) can be lithographically patterned to achieve the desired layout of parallel line-shaped emitters, in which adjacent lasers utilize identical semiconductor material and thereby achieve a degree of intrinsic optical uniformity. Under this LDRD project, we have fabricated arrays of uncoupled circular-aperture VCSELs to approximate a line-shaped illumination pattern, achieving optical fill factors ranging from 2% to 30%. We have applied these VCSEL arrays to demonstrate single and dual parallel line-filament triggering of PCSS devices. Moreover, we have developed a better understanding of the illumination requirements for stable triggering of multiple-filament PCSS devices using VCSEL arrays. We have found that reliable triggering of multiple filaments requires matching of the turn-on time of adjacent VCSEL line-shaped-arrays to within approximately 1 ns. Additionally, we discovered that reliable triggering of PCSS devices at low voltages requires more optical power than we obtained with our first generation of VCSEL arrays. A second generation of higher-power VCSEL arrays was designed and fabricated at the end of this LDRD project, and testing with PCSS devices is currently underway (as of September 2008).

  13. Beyond the single-atom response in absorption line shapes: probing a dense, laser-dressed helium gas with attosecond pulse trains.

    PubMed

    Liao, Chen-Ting; Sandhu, Arvinder; Camp, Seth; Schafer, Kenneth J; Gaarde, Mette B

    2015-04-10

    We investigate the absorption line shapes of laser-dressed atoms beyond the single-atom response, by using extreme ultraviolet (XUV) attosecond pulse trains to probe an optically thick helium target under the influence of a strong infrared (IR) field. We study the interplay between the IR-induced phase shift of the microscopic time-dependent dipole moment and the resonant-propagation-induced reshaping of the macroscopic XUV pulse. Our experimental and theoretical results show that as the optical depth increases, this interplay leads initially to a broadening of the IR-modified line shape, and subsequently, to the appearance of new, narrow features in the absorption line. PMID:25910116

  14. Neurons to algorithms LDRD final report.

    SciTech Connect

    Rothganger, Fredrick H.; Aimone, James Bradley; Warrender, Christina E.; Trumbo, Derek

    2013-09-01

    Over the last three years the Neurons to Algorithms (N2A) LDRD project teams has built infrastructure to discover computational structures in the brain. This consists of a modeling language, a tool that enables model development and simulation in that language, and initial connections with the Neuroinformatics community, a group working toward similar goals. The approach of N2A is to express large complex systems like the brain as populations of a discrete part types that have specific structural relationships with each other, along with internal and structural dynamics. Such an evolving mathematical system may be able to capture the essence of neural processing, and ultimately of thought itself. This final report is a cover for the actual products of the project: the N2A Language Specification, the N2A Application, and a journal paper summarizing our methods.

  15. Small space object imaging : LDRD final report.

    SciTech Connect

    Ackermann, Mark R.; Valley, Michael T.; Kearney, Sean Patrick

    2009-10-01

    We report the results of an LDRD effort to investigate new technologies for the identification of small-sized (mm to cm) debris in low-earth orbit. This small-yet-energetic debris presents a threat to the integrity of space-assets worldwide and represents significant security challenge to the international community. We present a nonexhaustive review of recent US and Russian efforts to meet the challenges of debris identification and removal and then provide a detailed description of joint US-Russian plans for sensitive, laser-based imaging of small debris at distances of hundreds of kilometers and relative velocities of several kilometers per second. Plans for the upcoming experimental testing of these imaging schemes are presented and a preliminary path toward system integration is identified.

  16. Computational Biology: A Strategic Initiative LDRD

    SciTech Connect

    Barksy, D; Colvin, M

    2002-02-07

    The goal of this Strategic Initiative LDRD project was to establish at LLNL a new core capability in computational biology, combining laboratory strengths in high performance computing, molecular biology, and computational chemistry and physics. As described in this report, this project has been very successful in achieving this goal. This success is demonstrated by the large number of referred publications, invited talks, and follow-on research grants that have resulted from this project. Additionally, this project has helped build connections to internal and external collaborators and funding agencies that will be critical to the long-term vitality of LLNL programs in computational biology. Most importantly, this project has helped establish on-going research groups in the Biology and Biotechnology Research Program, the Physics and Applied Technology Directorate, and the Computation Directorate. These groups include three laboratory staff members originally hired as post-doctoral researchers for this strategic initiative.

  17. LDRD Final Report: Global Optimization for Engineering Science Problems

    SciTech Connect

    HART,WILLIAM E.

    1999-12-01

    For a wide variety of scientific and engineering problems the desired solution corresponds to an optimal set of objective function parameters, where the objective function measures a solution's quality. The main goal of the LDRD ''Global Optimization for Engineering Science Problems'' was the development of new robust and efficient optimization algorithms that can be used to find globally optimal solutions to complex optimization problems. This SAND report summarizes the technical accomplishments of this LDRD, discusses lessons learned and describes open research issues.

  18. Building more powerful less expensive supercomputers using Processing-In-Memory (PIM) LDRD final report.

    SciTech Connect

    Murphy, Richard C.

    2009-09-01

    This report details the accomplishments of the 'Building More Powerful Less Expensive Supercomputers Using Processing-In-Memory (PIM)' LDRD ('PIM LDRD', number 105809) for FY07-FY09. Latency dominates all levels of supercomputer design. Within a node, increasing memory latency, relative to processor cycle time, limits CPU performance. Between nodes, the same increase in relative latency impacts scalability. Processing-In-Memory (PIM) is an architecture that directly addresses this problem using enhanced chip fabrication technology and machine organization. PIMs combine high-speed logic and dense, low-latency, high-bandwidth DRAM, and lightweight threads that tolerate latency by performing useful work during memory transactions. This work examines the potential of PIM-based architectures to support mission critical Sandia applications and an emerging class of more data intensive informatics applications. This work has resulted in a stronger architecture/implementation collaboration between 1400 and 1700. Additionally, key technology components have impacted vendor roadmaps, and we are in the process of pursuing these new collaborations. This work has the potential to impact future supercomputer design and construction, reducing power and increasing performance. This final report is organized as follow: this summary chapter discusses the impact of the project (Section 1), provides an enumeration of publications and other public discussion of the work (Section 1), and concludes with a discussion of future work and impact from the project (Section 1). The appendix contains reprints of the refereed publications resulting from this work.

  19. FY02 Engineering Technology Reports Volume 2: LDRD

    SciTech Connect

    Minichino, C; Meeker, D

    2003-05-19

    This report summarizes the science and technology research and development efforts in Lawrence Livermore National Laboratory's Engineering Directorate for FY2002, and exemplifies Engineering's 50-year history of developing the technologies needed to support the Laboratory's missions. Engineering has been a partner in every major program and project at the Laboratory throughout its existence and has prepared for this role with a skilled workforce and the technical resources developed through venues like the Laboratory Directed Research and Development Program (LDRD). This accomplishment is well summarized by Engineering's mission: ''To make programs succeed today and to ensure the vitality of the Laboratory tomorrow.'' Engineering's investment in new technologies is carried out through two programs, the ''Tech Base'' program (Volume I) and the LDRD program (Volume II). This report summarizes the LDRD portion of Engineering's Technology Program. LDRD is the vehicle for researching and developing those technologies and competencies that are cutting edge, or that require a significant level of research, or contain some unknown that needs to be fully understood. Tech Base is used to apply those technologies, or adapt them to a Laboratory need. The term commonly used for Tech Base projects is ''reduction to practice.'' Therefore, the LDRD report covered here has a strong research emphasis. Areas that are presented all fall into those needed to accomplish our mission. For FY2002, Engineering's LDRD projects were focused on mesoscale target fabrication and characterization, development of engineering computational capability, material studies and modeling, remote sensing and communications, and microtechnology for national security applications.

  20. Attosecond transient absorption in dense gases: Exploring the interplay between resonant pulse propagation and laser-induced line-shape control

    NASA Astrophysics Data System (ADS)

    Liao, Chen-Ting; Sandhu, Arvinder; Camp, Seth; Schafer, Kenneth J.; Gaarde, Mette B.

    2016-03-01

    We investigate the evolution of extreme ultraviolet (XUV) spectral line shapes in an optically thick helium gas under near-infrared (IR) perturbation. In our experimental and theoretical work, we systematically vary the IR intensity, time-delay, gas density, and IR polarization parameters to study line-shape modifications induced by collective interactions in a regime beyond the single-atom response of a thin, dilute gas. In both experiment and theory, we find that specific features in the frequency-domain absorption profile, and their evolution with propagation distance, can be attributed to the interplay between resonant attosecond pulse propagation and IR-induced phase shifts. Our calculations show that this interplay also manifests itself in the time domain, with the IR pulse influencing the reshaping of the XUV pulse propagating in the resonant medium.

  1. Self organizing software research : LDRD final report.

    SciTech Connect

    Osbourn, Gordon Cecil

    2004-01-01

    We have made progress in developing a new statistical mechanics approach to designing self organizing systems that is unique to SNL. The primary application target for this ongoing research has been the development of new kinds of nanoscale components and hardware systems. However, this research also enables an out of the box connection to the field of software development. With appropriate modification, the collective behavior physics ideas for enabling simple hardware components to self organize may also provide design methods for a new class of software modules. Our current physics simulations suggest that populations of these special software components would be able to self assemble into a variety of much larger and more complex software systems. If successful, this would provide a radical (disruptive technology) path to developing complex, high reliability software unlike any known today. This high risk, high payoff opportunity does not fit well into existing SNL funding categories, as it is well outside of the mainstreams of both conventional software development practices and the nanoscience research area that spawned it. This LDRD effort was aimed at developing and extending the capabilities of self organizing/assembling software systems, and to demonstrate the unique capabilities and advantages of this radical new approach for software development.

  2. Precision guided parachute LDRD final report

    SciTech Connect

    Gilkey, J.C.

    1996-07-01

    This report summarizes the results of the Precision Guided Parachute LDRD, a two year program at Sandia National Laboratories which developed a Global Positioning System (GPS) guided parachute capable of autonomous flight and landings. A detailed computer model of a gliding parachute was developed for software only simulations. A hardware in-the-loop simulator was developed and used for flight package system integration and design validation. Initial parachute drop tests were conducted at Sandia`s Coyote Canyon Cable Facility, followed by a series of airdrops using Ross Aircraft`s Twin Otter at the Burris Ranch Drop Zone. Final flights demonstrated in-flight wind estimation and the capability to fly a commanded heading. In the past, the cost and logistical complexity of an initial navigation system ruled out actively guiding a parachute. The advent of the low-cost, light-weight Global Positioning System (GPS) has eliminated this barrier. By using GPS position and velocity measurements, a guided parachute can autonomously steer itself to a targeted point on the ground through the use of control drums attached to the control lanyards of the parachute. By actively correcting for drop point errors and wind drift, the guidance accuracy of this system should be on the order of GPS position errors. This would be a significant improvement over unguided airdrops which may have errors of a mile or more.

  3. Final Report: CNC Micromachines LDRD No.10793

    SciTech Connect

    JOKIEL JR., BERNHARD; BENAVIDES, GILBERT L.; BIEG, LOTHAR F.; ALLEN, JAMES J.

    2003-04-01

    The three-year LDRD ''CNC Micromachines'' was successfully completed at the end of FY02. The project had four major breakthroughs in spatial motion control in MEMS: (1) A unified method for designing scalable planar and spatial on-chip motion control systems was developed. The method relies on the use of parallel kinematic mechanisms (PKMs) that when properly designed provide different types of motion on-chip without the need for post-fabrication assembly, (2) A new type of actuator was developed--the linear stepping track drive (LSTD) that provides open loop linear position control that is scalable in displacement, output force and step size. Several versions of this actuator were designed, fabricated and successfully tested. (3) Different versions of XYZ translation only and PTT motion stages were designed, successfully fabricated and successfully tested demonstrating absolutely that on-chip spatial motion control systems are not only possible, but are a reality. (4) Control algorithms, software and infrastructure based on MATLAB were created and successfully implemented to drive the XYZ and PTT motion platforms in a controlled manner. The control software is capable of reading an M/G code machine tool language file, decode the instructions and correctly calculate and apply position and velocity trajectories to the motion devices linear drive inputs to position the device platform along the trajectory as specified by the input file. A full and detailed account of design methodology, theory and experimental results (failures and successes) is provided.

  4. Idaho National Laboratory Annual Report FY 2013 LDRD Project Summaries

    SciTech Connect

    Dena Tomchak

    2014-03-01

    The FY 2013 LDRD Annual Report is a compendium of the diverse research performed to develop and ensure the INL’s technical capabilities support the current and future DOE missions and national research priorities. LDRD is essential to INL—it provides a means for the Laboratory to maintain scientific and technical vitality while funding highly innovative, high-risk science and technology research and development (R&D) projects. The program enhances technical capabilities at the Laboratory, providing scientific and engineering staff with opportunities to explore proof-of-principle ideas, advanced studies of innovative concepts, and preliminary technical analyses. Established by Congress in 1991, the LDRD Program proves its benefit each year through new programs, intellectual property, patents, copyrights, national and international awards, and publications.

  5. Hydrodynamics of maneuvering bodies: LDRD final report

    SciTech Connect

    Kempka, S.N.; Strickland, J.H.

    1994-01-01

    The objective of the ``Hydrodynamics of Maneuvering Bodies`` LDRD project was to develop a Lagrangian, vorticity-based numerical simulation of the fluid dynamics associated with a maneuvering submarine. Three major tasks were completed. First, a vortex model to simulate the wake behind a maneuvering submarine was completed, assuming the flow to be inviscid and of constant density. Several simulations were performed for a dive maneuver, each requiring less than 20 cpu seconds on a workstation. The technical details of the model and the simulations are described in a separate document, but are reviewed herein. Second, a gridless method to simulate diffusion processes was developed that has significant advantages over previous Lagrangian diffusion models. In this model, viscous diffusion of vorticity is represented by moving vortices at a diffusion velocity, and expanding the vortices as specified by the kinematics for a compressible velocity field. This work has also been documented previously, and is only reviewed herein. The third major task completed was the development of a vortex model to describe inviscid internal wave phenomena, and is the focus of this document. Internal wave phenomena in the stratified ocean can affect an evolving wake, and thus must be considered for naval applications. The vortex model for internal wave phenomena includes a new formulation for the generation of vorticity due to fluid density variations, and a vortex adoption algorithm that allows solutions to be carried to much longer times than previous investigations. Since many practical problems require long-time solutions, this new adoption algorithm is a significant step toward making vortex methods applicable to practical problems. Several simulations are described and compared with previous results to validate and show the advantages of the new model. An overview of this project is also included.

  6. Tactical Deployment and Management of Autonomous Agents, LDRD Final Report

    SciTech Connect

    Fink, Glenn A.

    2007-11-16

    This is the final report for FY07 for this ongoing LDRD. The project involves deriving a behavioral framework, algorithms, and science underlying a complex-adaptive network of cooperating sensors that secures the computational infrastructure of a multi-enterprise cooperative organization.

  7. Idaho National Laboratory LDRD Annual Report FY 2012

    SciTech Connect

    Dena Tomchak

    2013-03-01

    This report provides a glimpse into our diverse research and development portfolio, wwhich encompasses both advanced nuclear science and technology and underlying technologies. IN keeping with the mission, INL's LDRD program fosters technical capabilities necessary to support current and future DOE-Office of Nuclear Energy research and development needs.

  8. On the shape of the mass-function of dense clumps in the Hi-GAL fields . I. Spectral energy distribution determination and global properties of the mass-functions

    NASA Astrophysics Data System (ADS)

    Olmi, L.; Anglés-Alcázar, D.; Elia, D.; Molinari, S.; Montier, L.; Pestalozzi, M.; Pezzuto, S.; Polychroni, D.; Ristorcelli, I.; Rodon, J.; Schisano, E.; Smith, M. D.; Testi, L.; Thompson, M.

    2013-03-01

    Context. Stars form in dense, dusty clumps of molecular clouds, but little is known about their origin and evolution. In particular, the relationship between the mass distribution of these clumps (also known as the clump mass function or CMF) and the stellar initial mass function (IMF), is still poorly understood. Aims: To discern the "true" shape of the CMF and to better understand how the CMF may evolve toward the IMF, large samples of bona-fide pre- and proto-stellar clumps are required. The sensitive observations of the Herschel Space Observatory (HSO) are now allowing us to look at large clump populations in various clouds with different physical conditions. Methods: We analyze two fields in the Galactic plane mapped by HSO during its science demonstration phase (SDP), as part of the more complete and unbiased Herschel infrared GALactic Plane Survey (Hi-GAL). These fields underwent a source-extraction and flux-estimation pipeline, which allowed us to obtain a sample with thousands of clumps. Starless and proto-stellar clumps were separated using both color and positional criteria to find those coincident with MIPS 24 μm sources. We describe the probability density functions of the power-law and lognormal models that were used to fit the CMFs. For the lognormal model we applied several statistical techniques to the data and compared their results. Results: The CMFs of the two SDP fields show very similar shapes, but very different mass scales. This similarity is confirmed by the values of the best-fit parameters of either the power-law or lognormal model. The power-law model leads to almost identical CMF slopes, whereas the lognormal model shows that the CMFs have similar widths. Conclusions: The similar CMF shape but different mass scale represents an evidence that the overall process of star formation in the two regions is very different. When comparing with the IMF, we find that the width of the IMF is narrower than the measured widths of the CMF in the two

  9. Noncontact surface thermometry for microsystems: LDRD final report.

    SciTech Connect

    Abel, Mark (Georgia Institute of Technology, Atlanta, GA); Beecham, Thomas (Georgia Institute of Technology, Atlanta, GA); Graham, Samuel (Georgia Institute of Technology, Atlanta, GA); Kearney, Sean Patrick; Serrano, Justin Raymond; Phinney, Leslie Mary

    2006-10-01

    We describe a Laboratory Directed Research and Development (LDRD) effort to develop and apply laser-based thermometry diagnostics for obtaining spatially resolved temperature maps on working microelectromechanical systems (MEMS). The goal of the effort was to cultivate diagnostic approaches that could adequately resolve the extremely fine MEMS device features, required no modifications to MEMS device design, and which did not perturb the delicate operation of these extremely small devices. Two optical diagnostics were used in this study: microscale Raman spectroscopy and microscale thermoreflectance. Both methods use a low-energy, nonperturbing probe laser beam, whose arbitrary wavelength can be selected for a diffraction-limited focus that meets the need for micron-scale spatial resolution. Raman is exploited most frequently, as this technique provides a simple and unambiguous measure of the absolute device temperature for most any MEMS semiconductor or insulator material under steady state operation. Temperatures are obtained from the spectral position and width of readily isolated peaks in the measured Raman spectra with a maximum uncertainty near {+-}10 K and a spatial resolution of about 1 micron. Application of the Raman technique is demonstrated for V-shaped and flexure-style polycrystalline silicon electrothermal actuators, and for a GaN high-electron-mobility transistor. The potential of the Raman technique for simultaneous measurement of temperature and in-plane stress in silicon MEMS is also demonstrated and future Raman-variant diagnostics for ultra spatio-temporal resolution probing are discussed. Microscale thermoreflectance has been developed as a complement for the primary Raman diagnostic. Thermoreflectance exploits the small-but-measurable temperature dependence of surface optical reflectivity for diagnostic purposes. The temperature-dependent reflectance behavior of bulk silicon, SUMMiT-V polycrystalline silicon films and metal surfaces is

  10. LDRD final report on new homogeneous catalysts for direct olefin epoxidation (LDRD 52591).

    SciTech Connect

    Goldberg, Karen; Smythe, Nicole A.; Moore, Joshua T.; Stewart, Constantine A.; Kemp, Richard Alan; Miller, James Edward; Kornienko, Alexander (New Mexico Institute of Mining and Technology); Denney, Melanie C. (University of Washington); Cetto, Kara L.

    2006-02-01

    This report summarizes our findings during the study of a novel homogeneous epoxidation catalyst system that uses molecular oxygen as the oxidant, a ''Holy Grail'' in catalysis. While olefins (alkenes) that do not contain allylic hydrogens can be epoxidized directly using heterogeneous catalysts, most olefins cannot, and so a general, atom-efficient route is desired. While most of the work performed on this LDRD has been on pincer complexes of late transition metals, we also scouted out metal/ligand combinations that were significantly different, and unfortunately, less successful. Most of the work reported here deals with phosphorus-ligated Pd hydrides [(PCP)Pd-H]. We have demonstrated that molecular oxygen gas can insert into the Pd-H bond, giving a structurally characterized Pd-OOH species. This species reacts with oxygen acceptors such as olefins to donate an oxygen atom, although in various levels of selectivity, and to generate a [(PCP)Pd-OH] molecule. We discovered that the active [(PCP)Pd-H] active catalyst can be regenerated by addition of either CO or hydrogen. The demonstration of each step of the catalytic cycle is quite significant. Extensions to the pincer-Pd chemistry by attaching a fluorinated tail to the pincer designed to be used in solvents with higher oxygen solubilities are also presented.

  11. Final report on LDRD project "proliferation-resistant fuel cycles"

    SciTech Connect

    Brown, N W; Hassberger, J A

    1999-02-25

    This report provides a summary of LDRD work completed during 1997 and 1998 to develop the ideas and concepts that lead to the Secure, Transportable, Autonomous Reactor (STAR) program proposals to the DOE Nuclear Energy Research Initiative (NERI). The STAR program consists of a team of three national laboratories (LLNL, ANL, and LANL), three universities, (UC Berkeley, TAMU, and MIT) and the Westinghouse Research Center. Based on the LLNL work and their own efforts on related work this team prepared and integrated a package of twelve proposals that will carry the LDRD work outlined here into the next phase of development. We are proposing to develop a new nuclear system that meets stringent requirements for a high degree of safety and proliferation resistance, and also deals directly with the related nuclear waste and spent fuel management issues.

  12. LDRD final report on new homogeneous and supported oligomerization catalysts (LDRD 42461).

    SciTech Connect

    Hascall, Anthony G.; Kemp, Richard Alan

    2004-11-01

    The overall purpose of this LDRD is multifold. First, we are interested in preparing new homogeneous catalysts that can be used in the oligomerization of ethylene and in understanding commercially important systems better. Second, we are interested in attempting to support these new homogeneous catalysts in the pores of nano- or mesoporous materials in order to force new and unusual distributions of a-olefins to be formed during the oligomerization. Thus the overall purpose is to try to prepare new catalytic species and to possibly control the active site architecture in order to yield certain desired products during a catalytic reaction, much like nature does with enzymes. In order to rationally synthesize catalysts it is imperative to comprehend the function of the various components of the catalyst. In heterogeneous systems, it is of utmost importance to know how a support interacts with the active site of the catalyst. In fact, in the catalysis world this lack of fundamental understanding of the relationship between active site and support is the single largest reason catalysis is considered an 'empirical' or 'black box' science rather than a well-understood one. In this work we will be preparing novel ethylene oligomerization catalysts, which are normally P-O chelated homogeneous complexes, with new ligands that replace P with a stable carbene. We will also examine a commercially catalyst system and investigate the active site in it via X-ray crystallography. We will also attempt to support these materials inside the pores of nano- and mesoporous materials. Essentially, we will be tailoring the size and scale of the catalyst active site and its surrounding environment to match the size of the molecular product(s) we wish to make. The overall purpose of the study will be to prepare new homogeneous catalysts, and if successful in supporting them to examine the effects that steric constraints and pore structures can have on growing oligomer chains.

  13. Dense Hypervelocity Plasma Jets

    NASA Astrophysics Data System (ADS)

    Case, Andrew; Witherspoon, F. Douglas; Messer, Sarah; Bomgardner, Richard; Phillips, Michael; van Doren, David; Elton, Raymond; Uzun-Kaymak, Ilker

    2007-11-01

    We are developing high velocity dense plasma jets for fusion and HEDP applications. Traditional coaxial plasma accelerators suffer from the blow-by instability which limits the mass accelerated to high velocity. In the current design blow-by is delayed by a combination of electrode shaping and use of a tailored plasma armature created by injection of a high density plasma at a few eV generated by arrays of capillary discharges or sparkgaps. Experimental data will be presented for a complete 32 injector gun system built for driving rotation in the Maryland MCX experiment, including data on penetration of the plasma jet through a magnetic field. We present spectroscopic measurements of plasma velocity, temperature, and density, as well as total momentum measured using a ballistic pendulum. Measurements are in agreement with each other and with time of flight data from photodiodes and a multichannel PMT. Plasma density is above 10^15 cm-3, velocities range up to about 100 km/s. Preliminary results from a quadrature heterodyne HeNe interferometer are consistent with these results.

  14. Boundary Preserving Dense Local Regions.

    PubMed

    Kim, Jaechul; Grauman, Kristen

    2015-05-01

    We propose a dense local region detector to extract features suitable for image matching and object recognition tasks. Whereas traditional local interest operators rely on repeatable structures that often cross object boundaries (e.g., corners, scale-space blobs), our sampling strategy is driven by segmentation, and thus preserves object boundaries and shape. At the same time, whereas existing region-based representations are sensitive to segmentation parameters and object deformations, our novel approach to robustly sample dense sites and determine their connectivity offers better repeatability. In extensive experiments, we find that the proposed region detector provides significantly better repeatability and localization accuracy for object matching compared to an array of existing feature detectors. In addition, we show our regions lead to excellent results on two benchmark tasks that require good feature matching: weakly supervised foreground discovery and nearest neighbor-based object recognition. PMID:26353319

  15. From Idea to Innovation: The Role of LDRD Investments in Sandia's Recent Successful B61 Experiments.

    SciTech Connect

    Arrowsmith, Marie Danielle

    2015-11-01

    The Laboratory Directed Research and Development (LDRD) program, authorized by U.S. Congress in 1991, enables Department of Energy (DOE) laboratories to devote a small portion of their research funding to high-risk and potentially high-payoff research. Because it is high-risk, LDRD-supported research may not lead to immediate mission impacts; however, many successes at DOE labs can be traced back to investments in LDRD. LDRD investments have a history of enabling significant payoffs for long-running DOE and NNSA missions and for providing anticipatory new technologies that ultimately become critical to future missions. Many of Sandia National Laboratories’ successes can be traced back to investments in LDRD. Capabilities from three LDRDs were critical to recent tests of the B61-12 gravity bomb—tests that would previously have only been performed experimentally.

  16. FY06 LDRD Final Report Data Intensive Computing

    SciTech Connect

    Abdulla, G M

    2007-02-13

    The goal of the data intensive LDRD was to investigate the fundamental research issues underlying the application of High Performance Computing (HPC) resources to the challenges of data intensive computing. We explored these issues through four targeted case studies derived from growing LLNL programs: high speed text processing, massive semantic graph analysis, streaming image feature extraction, and processing of streaming sensor data. The ultimate goal of this analysis was to provide scalable data management algorithms to support the development of a predictive knowledge capability consistent with the direction of Aurora.

  17. Advanced polychromator systems for remote chemical sensing (LDRD project 52575).

    SciTech Connect

    Sinclair, Michael B.; Pfeifer, Kent Bryant; Allen, James Joe

    2005-01-01

    The objective of this LDRD project was to develop a programmable diffraction grating fabricated in SUMMiT V{trademark}. Two types of grating elements (vertical and rotational) were designed and demonstrated. The vertical grating element utilized compound leveraged bending and the rotational grating element used vertical comb drive actuation. This work resulted in two technical advances and one patent application. Also a new optical configuration of the Polychromator was demonstrated. The new optical configuration improved the optical efficiency of the system without degrading any other aspect of the system. The new configuration also relaxes some constraint on the programmable diffraction grating.

  18. LDRD project 151362 : low energy electron-photon transport.

    SciTech Connect

    Kensek, Ronald Patrick; Hjalmarson, Harold Paul; Magyar, Rudolph J.; Bondi, Robert James; Crawford, Martin James

    2013-09-01

    At sufficiently high energies, the wavelengths of electrons and photons are short enough to only interact with one atom at time, leading to the popular %E2%80%9Cindependent-atom approximation%E2%80%9D. We attempted to incorporate atomic structure in the generation of cross sections (which embody the modeled physics) to improve transport at lower energies. We document our successes and failures. This was a three-year LDRD project. The core team consisted of a radiation-transport expert, a solid-state physicist, and two DFT experts.

  19. Atoms in dense plasmas

    SciTech Connect

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs.

  20. Effect of temperature on the shape of spatial quasi-periodic oscillations of the refractive index of alkali atoms in an optically dense medium with a closed excitation contour of Δ type

    SciTech Connect

    Barantsev, K A; Litvinov, A N

    2014-10-31

    A theory of a closed excitation contour (Δ system) of a three-level atom in an optically dense medium is constructed with allowance for temperature. The spatial quasi-periodic oscillations of the refractive index in the system under study are shown to damp with increasing temperature. The range of temperatures at which these oscillations are most pronounced is found. (quantum optics)

  1. Final Report for the Virtual Reliability Realization System LDRD

    SciTech Connect

    DELLIN, THEODORE A.; HENDERSON, CHRISTOPHER L.; O'TOOLE, EDWARD J.

    2000-12-01

    Current approaches to reliability are not adequate to keep pace with the need for faster, better and cheaper products and systems. This is especially true in high consequence of failure applications. The original proposal for the LDRD was to look at this challenge and see if there was a new paradigm that could make reliability predictions, along with a quantitative estimate of the risk in that prediction, in a way that was faster, better and cheaper. Such an approach would be based on the underlying science models that are the backbone of reliability predictions. The new paradigm would be implemented in two software tools: the Virtual Reliability Realization System (VRRS) and the Reliability Expert System (REX). The three-year LDRD was funded at a reduced level for the first year ($120K vs. $250K) and not renewed. Because of the reduced funding, we concentrated on the initial development of the expertise system. We developed an interactive semiconductor calculation tool needed for reliability analyses. We also were able to generate a basic functional system using Microsoft Siteserver Commerce Edition and Microsoft Sequel Server. The base system has the capability to store Office documents from multiple authors, and has the ability to track and charge for usage. The full outline of the knowledge model has been incorporated as well as examples of various types of content.

  2. Nanoporous Silica Templated HeteroEpitaxy: Final LDRD Report.

    SciTech Connect

    Burckel, David Bruce; Koleske, Daniel; Rowen, Adam M.; Williams, John Dalton; Fan, Hongyou; Arrington, Christian L.

    2006-11-01

    This one-year out-of-the-box LDRD was focused on exploring the use of porous growth masks as a method for defect reduction during heteroepitaxial crystal growth. Initially our goal was to investigate porous silica as a growth mask, however, we expanded the scope of the research to include several other porous growth masks on various size scales, including mesoporous carbon, and the UV curable epoxy, SU-8. Use of SU-8 as a growth mask represents a new direction, unique in the extensive literature of patterned epitaxial growth, and presents the possibility of providing a single step growth mask. Additional research included investigation of pore viability via electrochemical deposition into high aspect ratio photoresist patterns and pilot work on using SU-8 as a DUV negative resist, another significant potential result. While the late start nature of this project pushed some of the initial research goals out of the time table, significant progress was made. 3 Acknowledgements This work was performed in part at the Nanoscience %40 UNM facility, a member of the National Nanotechnology Infrastructure Network, which is supported by the National Science Foundation (Grant ECS 03-35765). Sandia is multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United Stated Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported under the Sandia LDRD program (Project 99405). 4

  3. FY06 LDRD Final Report: Broadband Radiation and Scattering

    SciTech Connect

    Madsen, N; Fasenfest, B; White, D; Stowell, M; Sharpe, R; Jandhyala, V; Champagne, N; Rockway, J D; Pingenot, J

    2007-03-08

    This is the final report for LDRD 01-ERD-005. The Principle Investigator was Robert Sharpe. Collaborators included Niel Madsen, Benjamin Fasenfest, John D. Rockway, of the Defense Sciences Engineering Division (DSED), Vikram Jandhyala and James Pingenot from the University of Washington, and Mark Stowell of the Center for Applications Development and Software Engineering (CADSE). It should be noted that Benjamin Fasenfest and Mark Stowell were partially supported under other funding. The purpose of this LDRD effort was to enhance LLNL's computational electromagnetics capability in the area of broadband radiation and scattering. For radiation and scattering problems our transient EM codes are limited by the approximate Radiation Boundary Conditions (RBC's) used to model the radiation into an infinite space. Improved RBC's were researched, developed, and incorporated into the existing EMSolve finite-element code to provide a 10-100x improvement in the accuracy of the boundary conditions. Section I provides an introduction to the project and the project goals. Section II provides a summary of the project's research and accomplishments as presented in the attached papers.

  4. Selected Examples of LDRD Projects Supporting Test Ban Treaty Verification and Nonproliferation

    SciTech Connect

    Jackson, K.; Al-Ayat, R.; Walter, W. R.

    2015-02-23

    The Laboratory Directed Research and Development (LDRD) Program at the DOE National Laboratories was established to ensure the scientific and technical vitality of these institutions and to enhance the their ability to respond to evolving missions and anticipate national needs. LDRD allows the Laboratory directors to invest a percentage of their total annual budget in cutting-edge research and development projects within their mission areas. We highlight a selected set of LDRD-funded projects, in chronological order, that have helped provide capabilities, people and infrastructure that contributed greatly to our ability to respond to technical challenges in support of test ban treaty verification and nonproliferation.

  5. THz transceiver characterization : LDRD project 139363 final report.

    SciTech Connect

    Nordquist, Christopher Daniel; Wanke, Michael Clement; Cich, Michael Joseph; Reno, John Louis; Fuller, Charles T.; Wendt, Joel Robert; Lee, Mark; Grine, Albert D.

    2009-09-01

    LDRD Project 139363 supported experiments to quantify the performance characteristics of monolithically integrated Schottky diode + quantum cascade laser (QCL) heterodyne mixers at terahertz (THz) frequencies. These integrated mixers are the first all-semiconductor THz devices to successfully incorporate a rectifying diode directly into the optical waveguide of a QCL, obviating the conventional optical coupling between a THz local oscillator and rectifier in a heterodyne mixer system. This integrated mixer was shown to function as a true heterodyne receiver of an externally received THz signal, a breakthrough which may lead to more widespread acceptance of this new THz technology paradigm. In addition, questions about QCL mode shifting in response to temperature, bias, and external feedback, and to what extent internal frequency locking can improve stability have been answered under this project.

  6. Retrospective on the Seniors' Council Tier 1 LDRD portfolio.

    SciTech Connect

    Ballard, William Parker

    2012-04-01

    This report describes the Tier 1 LDRD portfolio, administered by the Seniors Council between 2003 and 2011. 73 projects were sponsored over the 9 years of the portfolio at a cost of $10.5 million which includes $1.9M of a special effort in directed innovation targeted at climate change and cyber security. Two of these Tier 1 efforts were the seeds for the Grand Challenge LDRDs in Quantum Computing and Next Generation Photovoltaic conversion. A few LDRDs were terminated early when it appeared clear that the research was not going to succeed. A great many more were successful and led to full Tier 2 LDRDs or direct customer sponsorship. Over a dozen patents are in various stages of prosecution from this work, and one project is being submitted for an R and D 100 award.

  7. Influence of the finite linewidth of the laser radiation spectrum on the shape of the coherent population trapping resonance line in an optically dense medium with a buffer gas

    SciTech Connect

    Barantsev, K. A. Popov, E. N.; Litvinov, A. N.

    2015-11-15

    The theory of coherent population trapping resonance is developed for the finite linewidth of the laser radiation spectrum in an optically dense medium of Λ atoms in a cell with a buffer gas. Equations are derived for the atomic density matrix and laser emission spectrum transfer in a cell with working and buffer gases at a finite temperature. The dependence of the quality factor of coherent population trapping resonance on the linewidth of the laser radiation spectrum is studied by measuring transmitted radiation and fluorescence signals.

  8. Visualization of expanding warm dense gold and diamond heated uniformly by laser-generated ion beams

    NASA Astrophysics Data System (ADS)

    Bang, W.; Albright, B. J.; Bradley, P. A.; Gautier, D. C.; Palaniyappan, S.; Vold, E. L.; Santiago Cordoba, M. A.; Hamilton, C. E.; Fernández, J. C.

    2015-11-01

    With a laser-generated beam of quasi-monoenergetic ions, a solid density target can be heated uniformly and isochorically. On the LANL Trident laser facility, we have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils. We visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperatures of these heated samples from the measured expansion speeds of gold and diamond into vacuum. These temperatures are in good agreement with the expected temperatures calculated using the total deposited energy into the cold targets and SESAME equation-of-state tables at solid densities. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics. *This work is sponsored by the LANL LDRD Program.

  9. Spatial and temporal resolution of fluid flows: LDRD final report

    SciTech Connect

    Tieszen, S.R.; O`Hern, T.J.; Schefer, R.W.; Perea, L.D.

    1998-02-01

    This report describes a Laboratory Directed Research and Development (LDRD) activity to develop a diagnostic technique for simultaneous temporal and spatial resolution of fluid flows. The goal is to obtain two orders of magnitude resolution in two spatial dimensions and time simultaneously. The approach used in this study is to scale up Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) to acquire meter-size images at up to 200 frames/sec. Experiments were conducted in buoyant, fully turbulent, non-reacting and reacting plumes with a base diameter of one meter. The PIV results were successful in the ambient gas for all flows, and in the plume for non-reacting helium and reacting methane, but not reacting hydrogen. No PIV was obtained in the hot combustion product region as the seed particles chosen vaporized. Weak signals prevented PLIF in the helium. However, in reacting methane flows, PLIF images speculated to be from Poly-Aromatic-Hydrocarbons were obtained which mark the flame sheets. The results were unexpected and very insightful. A natural fluorescence from the seed particle vapor was also noted in the hydrogen tests.

  10. Obstacle detection for autonomous navigation : an LDRD final report.

    SciTech Connect

    Padilla, Denise D.

    2004-03-01

    This report summarizes the analytical and experimental efforts for the Laboratory Directed Research and Development (LDRD) project entitled 'Obstacle Detection for Autonomous Navigation'. The principal goal of this project was to develop a mathematical framework for obstacle detection. The framework provides a basis for solutions to many complex obstacle detection problems critical to successful autonomous navigation. Another goal of this project was to characterize sensing requirements in terms of physical characteristics of obstacles, vehicles, and terrain. For example, a specific vehicle traveling at a specific velocity over a specific terrain requires a sensor with a certain range of detection, resolution, field-of-view, and sufficient sensitivity to specific obstacle characteristics. In some cases, combinations of sensors were required to distinguish between different hazardous obstacles and benign terrain. In our framework, the problem was posed as a multidimensional, multiple-hypothesis, pattern recognition problem. Features were extracted from selected sensors that allow hazardous obstacles to be distinguished from benign terrain and other types of obstacles. Another unique thrust of this project was to characterize different terrain classes with respect to both positive (e.g., rocks, trees, fences) and negative (e.g., holes, ditches, drop-offs) obstacles. The density of various hazards per square kilometer was statistically quantified for different terrain categories (e.g., high desert, ponderosa forest, and prairie). This quantification reflects the scale, or size, and mobility of different types of vehicles. The tradeoffs between obstacle detection, position location, path planning, and vehicle mobility capabilities were also to be characterized.

  11. LDRD 102610 final report new processes for innovative microsystems engineering with predictive simulation.

    SciTech Connect

    Mattsson, Ann Elisabet; Mitchell, Scott A.; Thomas, Stephen W.

    2007-08-01

    This LDRD Final report describes work that Stephen W. Thomas performed in 2006. The initial problem was to develop a modeling, simulation, and optimization strategy for the design of a high speed microsystem switch. The challenge was to model the right phenomena at the right level of fidelity, and capture the right design parameters. This effort focused on the design context, in contrast to other Sandia efforts focus on high-fidelity assessment. This report contains the initial proposal and the annual progress report. This report also describes exploratory work on micromaching using femtosecond lasers. Steve's time developing a proposal and collaboration on this topic was partly funded by this LDRD.

  12. Interface physics in microporous media : LDRD final report.

    SciTech Connect

    Yaklin, Melissa A.; Knutson, Chad E.; Noble, David R.; Aragon, Alicia R.; Chen, Ken Shuang; Giordano, Nicholas J.; Brooks, Carlton, F.; Pyrak-Nolte, Laura J.; Liu, Yihong

    2008-09-01

    This document contains a summary of the work performed under the LDRD project entitled 'Interface Physics in Microporous Media'. The presence of fluid-fluid interfaces, which can carry non-zero stresses, distinguishes multiphase flows from more readily understood single-phase flows. In this work the physics active at these interfaces has been examined via a combined experimental and computational approach. One of the major difficulties of examining true microporous systems of the type found in filters, membranes, geologic media, etc. is the geometric uncertainty. To help facilitate the examination of transport at the pore-scale without this complication, a significant effort has been made in the area of fabrication of both two-dimensional and three-dimensional micromodels. Using these micromodels, multiphase flow experiments have been performed for liquid-liquid and liquid-gas systems. Laser scanning confocal microscopy has been utilized to provide high resolution, three-dimensional reconstructions as well as time resolved, two-dimensional reconstructions. Computational work has focused on extending lattice Boltzmann (LB) and finite element methods for probing the interface physics at the pore scale. A new LB technique has been developed that provides over 100x speed up for steady flows in complex geometries. A new LB model has been developed that allows for arbitrary density ratios, which has been a significant obstacle in applying LB to air-water flows. A new reduced order model has been developed and implemented in finite element code for examining non-equilibrium wetting in microchannel systems. These advances will enhance Sandia's ability to quantitatively probe the rich interfacial physics present in microporous systems.

  13. Dense suspension splash

    NASA Astrophysics Data System (ADS)

    Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Schaarsberg, Martin H. Klein; Jaeger, Heinrich M.; Zhang, Wendy W.

    2014-11-01

    Impact of a dense suspension drop onto a solid surface at speeds of several meters-per-second splashes by ejecting individual liquid-coated particles. Suppression or reduction of this splash is important for thermal spray coating and additive manufacturing. Accomplishing this aim requires distinguishing whether the splash is generated by individual scattering events or by collective motion reminiscent of liquid flow. Since particle inertia dominates over surface tension and viscous drag in a strong splash, we model suspension splash using a discrete-particle simulation in which the densely packed macroscopic particles experience inelastic collisions but zero friction or cohesion. Numerical results based on this highly simplified model are qualitatively consistent with observations. They also show that approximately 70% of the splash is generated by collective motion. Here an initially downward-moving particle is ejected into the splash because it experiences a succession of low-momentum-change collisions whose effects do not cancel but instead accumulate. The remainder of the splash is generated by scattering events in which a small number of high-momentum-change collisions cause a particle to be ejected upwards. Current Address: Physics of Fluids Group, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

  14. Warm dense crystallography

    NASA Astrophysics Data System (ADS)

    Valenza, Ryan A.; Seidler, Gerald T.

    2016-03-01

    The intense femtosecond-scale pulses from x-ray free electron lasers (XFELs) are able to create and interrogate interesting states of matter characterized by long-lived nonequilibrium semicore or core electron occupancies or by the heating of dense phases via the relaxation cascade initiated by the photoelectric effect. We address here the latter case of "warm dense matter" (WDM) and investigate the observable consequences of x-ray heating of the electronic degrees of freedom in crystalline systems. We report temperature-dependent density functional theory calculations for the x-ray diffraction from crystalline LiF, graphite, diamond, and Be. We find testable, strong signatures of condensed-phase effects that emphasize the importance of wide-angle scattering to study nonequilibrium states. These results also suggest that the reorganization of the valence electron density at eV-scale temperatures presents a confounding factor to achieving atomic resolution in macromolecular serial femtosecond crystallography (SFX) studies at XFELs, as performed under the "diffract before destroy" paradigm.

  15. DENSE MEDIUM CYCLONE OPTIMIZATON

    SciTech Connect

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  16. Dense Hypervelocity Plasma Jets

    NASA Astrophysics Data System (ADS)

    Witherspoon, F. Douglas; Case, Andrew; Phillips, Michael W.

    2006-10-01

    High velocity dense plasma jets are under continued experimental development for a variety of fusion applications including refueling, disruption mitigation, rotation drive, and magnetized target fusion. The technical goal is to accelerate plasma slugs of density >10^17 cm-3 and total mass >100 micrograms to velocities >200 km/s. The approach utilizes symmetrical injection of very high density plasma into a coaxial EM accelerator having a tailored cross-section geometry to prevent formation of the blow-by instability. Injected plasma is generated by electrothermal capillary discharges using either cylindrical capillaries or a newer toroidal spark gap arrangement that has worked at pressures as low as 3.5 x10-6 Torr in bench tests. Experimental plasma data will be presented for a complete 32 injector accelerator system recently built for driving rotation in the Maryland MCX experiment which utilizes the cylindrical capillaries, and also for a 50 spark gap test unit currently under construction.

  17. Advancing the Fundamental Understanding of Fission: 2014 LDRD 20120077DR Review

    SciTech Connect

    White, Morgan C.; Tovesson, Fredrik K.; Sierk, Arnold John

    2014-02-06

    The following slides were presented as part of the LDRD 20120077DR Progress Appraisal Review held Tuesday, February 4, 2014. This is part of an ongoing project assessment the previous of which was documented in LA-UR-13-21182. This presentation documents the progress made against the goals agreed to as part of the 2013 review.

  18. Sensor Based Process Control (SBPC) Laboratories Directed Research and Development (LDRD)

    SciTech Connect

    Wronosky, J.B.

    1993-03-01

    This report describes the activities and results of an LDRD entitled Sensor Based Process Control. This research examined the needs of the plating industry for monitor and control capabilities with particular emphasis on water effluent from rinse baths. A personal computer-based monitor and control development system was used as a test bed.

  19. Geometrical Optics of Dense Aerosols

    SciTech Connect

    Hay, Michael J.; Valeo, Ernest J.; Fisch, Nathaniel J.

    2013-04-24

    Assembling a free-standing, sharp-edged slab of homogeneous material that is much denser than gas, but much more rare ed than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed fi eld, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the nite particle density reduces the eff ective Stokes number of the flow, a critical result for controlled focusing. __________________________________________________

  20. Ariel's Densely Pitted Surface

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This mosaic of the four highest-resolution images of Ariel represents the most detailed Voyager 2 picture of this satellite of Uranus. The images were taken through the clear filter of Voyager's narrow-angle camera on Jan. 24, 1986, at a distance of about 130,000 kilometers (80,000 miles). Ariel is about 1,200 km (750 mi) in diameter; the resolution here is 2.4 km (1.5 mi). Much of Ariel's surface is densely pitted with craters 5 to 10 km (3 to 6 mi) across. These craters are close to the threshold of detection in this picture. Numerous valleys and fault scarps crisscross the highly pitted terrain. Voyager scientists believe the valleys have formed over down-dropped fault blocks (graben); apparently, extensive faulting has occurred as a result of expansion and stretching of Ariel's crust. The largest fault valleys, near the terminator at right, as well as a smooth region near the center of this image, have been partly filled with deposits that are younger and less heavily cratered than the pitted terrain. Narrow, somewhat sinuous scarps and valleys have been formed, in turn, in these young deposits. It is not yet clear whether these sinuous features have been formed by faulting or by the flow of fluids.

    JPL manages the Voyager project for NASA's Office of Space Science.

  1. Hybrid-Based Dense Stereo Matching

    NASA Astrophysics Data System (ADS)

    Chuang, T. Y.; Ting, H. W.; Jaw, J. J.

    2016-06-01

    Stereo matching generating accurate and dense disparity maps is an indispensable technique for 3D exploitation of imagery in the fields of Computer vision and Photogrammetry. Although numerous solutions and advances have been proposed in the literature, occlusions, disparity discontinuities, sparse texture, image distortion, and illumination changes still lead to problematic issues and await better treatment. In this paper, a hybrid-based method based on semi-global matching is presented to tackle the challenges on dense stereo matching. To ease the sensitiveness of SGM cost aggregation towards penalty parameters, a formal way to provide proper penalty estimates is proposed. To this end, the study manipulates a shape-adaptive cross-based matching with an edge constraint to generate an initial disparity map for penalty estimation. Image edges, indicating the potential locations of occlusions as well as disparity discontinuities, are approved by the edge drawing algorithm to ensure the local support regions not to cover significant disparity changes. Besides, an additional penalty parameter 𝑃𝑒 is imposed onto the energy function of SGM cost aggregation to specifically handle edge pixels. Furthermore, the final disparities of edge pixels are found by weighting both values derived from the SGM cost aggregation and the U-SURF matching, providing more reliable estimates at disparity discontinuity areas. Evaluations on Middlebury stereo benchmarks demonstrate satisfactory performance and reveal the potency of the hybrid-based dense stereo matching method.

  2. Diagnostic development for determining the joint temperature/soot statistics in hydrocarbon-fueled pool fires : LDRD final report.

    SciTech Connect

    Casteneda, Jaime N.; Frederickson, Kraig; Grasser, Thomas W.; Hewson, John C.; Kearney, Sean Patrick; Luketa, Anay Josephine

    2009-09-01

    A joint temperature/soot laser-based optical diagnostic was developed for the determination of the joint temperature/soot probability density function (PDF) for hydrocarbon-fueled meter-scale turbulent pool fires. This Laboratory Directed Research and Development (LDRD) effort was in support of the Advanced Simulation and Computing (ASC) program which seeks to produce computational models for the simulation of fire environments for risk assessment and analysis. The development of this laser-based optical diagnostic is motivated by the need for highly-resolved spatio-temporal information for which traditional diagnostic probes, such as thermocouples, are ill-suited. The in-flame gas temperature is determined from the shape of the nitrogen Coherent Anti-Stokes Raman Scattering (CARS) signature and the soot volume fraction is extracted from the intensity of the Laser-Induced Incandescence (LII) image of the CARS probed region. The current state of the diagnostic will be discussed including the uncertainty and physical limits of the measurements as well as the future applications of this probe.

  3. Development of highly integrated magetically and electrostatically actuated micropumps : LDRD 64709 final report.

    SciTech Connect

    Sosnowchik, Brian D.; Galambos, Paul C.; Hendrix, Jason R.; Zwolinski, Andrew

    2003-12-01

    The pump and actuator systems designed and built in the SUMMiT{trademark} process, Sandia's surface micromachining polysilicon MEMS (Micro-Electro-Mechanical Systems) fabrication technology, on the previous campus executive program LDRD (SAND2002-0704P) with FSU/FAMU (Florida State University/Florida Agricultural and Mechanical University) were characterized in this LDRD. These results demonstrated that the device would pump liquid against the flow resistance of a microfabricated channel, but the devices were determined to be underpowered for reliable pumping. As a result a new set of SUMMiT{trademark} pumps with actuators that generate greater torque will be designed and submitted for fabrication. In this document we will report details of dry actuator/pump assembly testing, wet actuator/pump testing, channel resistance characterization, and new pump/actuator design recommendations.

  4. Final LDRD report : infrared detection and power generation using self-assembled quantum dots.

    SciTech Connect

    Cederberg, Jeffrey George; Ellis, Robert; Shaner, Eric Arthur

    2008-02-01

    Alternative solutions are desired for mid-wavelength and long-wavelength infrared radiation detection and imaging arrays. We have investigated quantum dot infrared photodetectors (QDIPs) as a possible solution for long-wavelength infrared (8 to 12 {mu}m) radiation sensing. This document provides a summary for work done under the LDRD 'Infrared Detection and Power Generation Using Self-Assembled Quantum Dots'. Under this LDRD, we have developed QDIP sensors and made efforts to improve these devices. While the sensors fabricated show good responsivity at 80 K, their detectivity is limited by high noise current. Following efforts concentrated on how to reduce or eliminate this problem, but with no clear path was identified to the desired performance improvements.

  5. Exploration of cloud computing late start LDRD #149630 : Raincoat. v. 2.1.

    SciTech Connect

    Echeverria, Victor T.; Metral, Michael David; Leger, Michelle A.; Gabert, Kasimir Georg; Edgett, Patrick Garrett; Thai, Tan Q.

    2010-09-01

    This report contains documentation from an interoperability study conducted under the Late Start LDRD 149630, Exploration of Cloud Computing. A small late-start LDRD from last year resulted in a study (Raincoat) on using Virtual Private Networks (VPNs) to enhance security in a hybrid cloud environment. Raincoat initially explored the use of OpenVPN on IPv4 and demonstrates that it is possible to secure the communication channel between two small 'test' clouds (a few nodes each) at New Mexico Tech and Sandia. We extended the Raincoat study to add IPSec support via Vyatta routers, to interface with a public cloud (Amazon Elastic Compute Cloud (EC2)), and to be significantly more scalable than the previous iteration. The study contributed to our understanding of interoperability in a hybrid cloud.

  6. Final report on LDRD project 52722 : radiation hardened optoelectronic components for space-based applications.

    SciTech Connect

    Hargett, Terry W.; Serkland, Darwin Keith; Blansett, Ethan L.; Geib, Kent Martin; Sullivan, Charles Thomas; Hawkins, Samuel D.; Wrobel, Theodore Frank; Keeler, Gordon Arthur; Klem, John Frederick; Medrano, Melissa R.; Peake, Gregory Merwin; Karpen, Gary D.; Montano, Victoria A.

    2003-12-01

    This report describes the research accomplishments achieved under the LDRD Project 'Radiation Hardened Optoelectronic Components for Space-Based Applications.' The aim of this LDRD has been to investigate the radiation hardness of vertical-cavity surface-emitting lasers (VCSELs) and photodiodes by looking at both the effects of total dose and of single-event upsets on the electrical and optical characteristics of VCSELs and photodiodes. These investigations were intended to provide guidance for the eventual integration of radiation hardened VCSELs and photodiodes with rad-hard driver and receiver electronics from an external vendor for space applications. During this one-year project, we have fabricated GaAs-based VCSELs and photodiodes, investigated ionization-induced transient effects due to high-energy protons, and measured the degradation of performance from both high-energy protons and neutrons.

  7. LDRD final report : robust analysis of large-scale combinatorial applications.

    SciTech Connect

    Carr, Robert D.; Morrison, Todd; Hart, William Eugene; Benavides, Nicolas L.; Greenberg, Harvey J.; Watson, Jean-Paul; Phillips, Cynthia Ann

    2007-09-01

    Discrete models of large, complex systems like national infrastructures and complex logistics frameworks naturally incorporate many modeling uncertainties. Consequently, there is a clear need for optimization techniques that can robustly account for risks associated with modeling uncertainties. This report summarizes the progress of the Late-Start LDRD 'Robust Analysis of Largescale Combinatorial Applications'. This project developed new heuristics for solving robust optimization models, and developed new robust optimization models for describing uncertainty scenarios.

  8. Overview of Stellarator Divertor Studies: Final Report of LDRD Project 01-ERD-069

    SciTech Connect

    Fenstermacher, M E; Rognlien, T D; Koniges, A; Unmansky, M; Hill, D N

    2003-01-21

    A summary is given of the work carried out under the LDRD project 01-ERD-069 entitled Stellarator Divertor Studies. This project has contributed to the development of a three-dimensional edge-plasma modeling and divertor diagnostic design capabilities at LLNL. Results are demonstrated by sample calculations and diagnostic possibilities for the edge plasma of the proposed U.S. National Compact Stellarator Experiment device. Details of the work are contained in accompanying LLNL reports that have been accepted for publication.

  9. Injection-locked composite lasers for mm-wave modulation : LDRD 117819 final report.

    SciTech Connect

    Wendt, Joel Robert; Vawter, Gregory Allen; Raring, James; Tauke-Pedretti, Anna; Alford, Charles Fred; Skogen, Erik J.; Chow, Weng Wah; Cajas, Florante G.; Overberg, Mark E.; Torres, David L.; Peake, Gregory Merwin

    2010-09-01

    This report summarizes a 3-year LDRD program at Sandia National Laboratories exploring mutual injection locking of composite-cavity lasers for enhanced modulation responses. The program focused on developing a fundamental understanding of the frequency enhancement previously demonstrated for optically injection locked lasers. This was then applied to the development of a theoretical description of strongly coupled laser microsystems. This understanding was validated experimentally with a novel 'photonic lab bench on a chip'.

  10. Efficient Probability of Failure Calculations for QMU using Computational Geometry LDRD 13-0144 Final Report

    SciTech Connect

    Mitchell, Scott A.; Ebeida, Mohamed Salah; Romero, Vicente J.; Swiler, Laura Painton; Rushdi, Ahmad A.; Abdelkader, Ahmad

    2015-09-01

    This SAND report summarizes our work on the Sandia National Laboratory LDRD project titled "Efficient Probability of Failure Calculations for QMU using Computational Geometry" which was project #165617 and proposal #13-0144. This report merely summarizes our work. Those interested in the technical details are encouraged to read the full published results, and contact the report authors for the status of the software and follow-on projects.

  11. FY07 LDRD Final Report Precision, Split Beam, Chirped-Pulse, Seed Laser Technology

    SciTech Connect

    Dawson, J W; Messerly, M J; Phan, H H; Crane, J K; Beach, R J; Siders, C W; Barty, C J

    2009-11-12

    The goal of this LDRD ER was to develop a robust and reliable technology to seed high-energy laser systems with chirped pulses that can be amplified to kilo-Joule energies and recompressed to sub-picosecond pulse widths creating extremely high peak powers suitable for petawatt class physics experiments. This LDRD project focused on the development of optical fiber laser technologies compatible with the current long pulse National Ignition Facility (NIF) seed laser. New technologies developed under this project include, high stability mode-locked fiber lasers, fiber based techniques for reduction of compressed pulse pedestals and prepulses, new compact stretchers based on chirped fiber Bragg gratings (CFBGs), new techniques for manipulation of chirped pulses prior to amplification and new high-energy fiber amplifiers. This project was highly successful and met virtually all of its goals. The National Ignition Campaign has found the results of this work to be very helpful. The LDRD developed system is being employed in experiments to engineer the Advanced Radiographic Capability (ARC) front end and the fully engineered version of the ARC Front End will employ much of the technology and techniques developed here.

  12. Multi-attribute criteria applied to electric generation energy system analysis LDRD.

    SciTech Connect

    Kuswa, Glenn W.; Tsao, Jeffrey Yeenien; Drennen, Thomas E.; Zuffranieri, Jason V.; Paananen, Orman Henrie; Jones, Scott A.; Ortner, Juergen G.; Brewer, Jeffrey D.; Valdez, Maximo M.

    2005-10-01

    This report began with a Laboratory-Directed Research and Development (LDRD) project to improve Sandia National Laboratories multidisciplinary capabilities in energy systems analysis. The aim is to understand how various electricity generating options can best serve needs in the United States. The initial product is documented in a series of white papers that span a broad range of topics, including the successes and failures of past modeling studies, sustainability, oil dependence, energy security, and nuclear power. Summaries of these projects are included here. These projects have provided a background and discussion framework for the Energy Systems Analysis LDRD team to carry out an inter-comparison of many of the commonly available electric power sources in present use, comparisons of those options, and efforts needed to realize progress towards those options. A computer aid has been developed to compare various options based on cost and other attributes such as technological, social, and policy constraints. The Energy Systems Analysis team has developed a multi-criteria framework that will allow comparison of energy options with a set of metrics that can be used across all technologies. This report discusses several evaluation techniques and introduces the set of criteria developed for this LDRD.

  13. Final report on LDRD project :leaky-mode VCSELs for photonic logic circuits.

    SciTech Connect

    Hargett, Terry W.; Hadley, G. Ronald; Serkland, Darwin Keith; Blansett, Ethan L.; Geib, Kent Martin; Sullivan, Charles Thomas; Keeler, Gordon Arthur; Bauer, Thomas; Ongstand, Andrea; Medrano, Melissa R.; Peake, Gregory Merwin; Montano, Victoria A.

    2005-11-01

    This report describes the research accomplishments achieved under the LDRD Project ''Leaky-mode VCSELs for photonic logic circuits''. Leaky-mode vertical-cavity surface-emitting lasers (VCSELs) offer new possibilities for integration of microcavity lasers to create optical microsystems. A leaky-mode VCSEL output-couples light laterally, in the plane of the semiconductor wafer, which allows the light to interact with adjacent lasers, modulators, and detectors on the same wafer. The fabrication of leaky-mode VCSELs based on effective index modification was proposed and demonstrated at Sandia in 1999 but was not adequately developed for use in applications. The aim of this LDRD has been to advance the design and fabrication of leaky-mode VCSELs to the point where initial applications can be attempted. In the first and second years of this LDRD we concentrated on overcoming previous difficulties in the epitaxial growth and fabrication of these advanced VCSELs. In the third year, we focused on applications of leaky-mode VCSELs, such as all-optical processing circuits based on gain quenching.

  14. Final Report on LDRD Project: High-Bandwidth Optical Data Interconnects for Satellite Applications

    SciTech Connect

    SERKLAND, DARWIN K.; GEIB, KENT M.; BLANSETT, ETHAN L.; KARPEN, GARY D.; PEAKE, GREGORY M.; HARGETT, TERRY; MONTANO, VICTORIA; SULLIVAN, CHARLES T.; ALLERMAN, ANDREW A.; RIENSTRA, JEFFREY L.

    2003-04-01

    This report describes the research accomplishments achieved under the LDRD Project ''High-Bandwidth Optical Data Interconnects for Satellite Applications.'' The goal of this LDRD has been to address the future needs of focal-plane-array (FPA) sensors by exploring the use of high-bandwidth fiber-optic interconnects to transmit FPA signals within a satellite. We have focused primarily on vertical-cavity surface-emitting laser (VCSEL) based transmitters, due to the previously demonstrated immunity of VCSELs to total radiation doses up to 1 Mrad. In addition, VCSELs offer high modulation bandwidth (roughly 10 GHz), low power consumption (roughly 5 mW), and high coupling efficiency (greater than -3dB) to optical fibers. In the first year of this LDRD, we concentrated on the task of transmitting analog signals from a cryogenic FPA to a remote analog-to-digital converter. In the second year, we considered the transmission of digital signals produced by the analog-to-digital converter to a remote computer on the satellite. Specifically, we considered the situation in which the FPA, analog-to-digital converter, and VCSEL-based transmitter were all cooled to cryogenic temperatures. This situation requires VCSELs that operate at cryogenic temperature, dissipate minimal heat, and meet the electrical drive requirements in terms of voltage, current, and bandwidth.

  15. Final report of LDRD project: Electromagnetic impulse radar for detection of underground structures

    SciTech Connect

    Loubriel, G.; Aurand, J.; Buttram, M.; Zutavern, F.; Brown, D.; Helgeson, W.

    1998-03-01

    This report provides a summary of the LDRD project titled: Electromagnetic impulse radar for the detection of underground structures. The project met all its milestones even with a tight two year schedule and total funding of $400 k. The goal of the LDRD was to develop and demonstrate a ground penetrating radar (GPR) that is based on high peak power, high repetition rate, and low center frequency impulses. The idea of this LDRD is that a high peak power, high average power radar based on the transmission of short impulses can be utilized effect can be utilized for ground penetrating radar. This direct time-domain system the authors are building seeks to increase penetration depth over conventional systems by using: (1) high peak power, high repetition rate operation that gives high average power, (2) low center frequencies that better penetrate the ground, and (3) short duration impulses that allow for the use of downward looking, low flying platforms that increase the power on target relative to a high flying platform. Specifically, chirped pulses that are a microsecond in duration require (because it is difficult to receive during transmit) platforms above 150 m (and typically 1 km) while this system, theoretically could be at 10 m above the ground. The power on target decays with distance squared so the ability to use low flying platforms is crucial to high penetration. Clutter is minimized by time gating the surface clutter return. Short impulses also allow gating (out) the coupling of the transmit and receive antennas.

  16. Precision formed micro magnets: LDRD project summary report

    SciTech Connect

    CHRISTENSON,TODD R.; GARINO,TERRY J.; VENTURINI,EUGENE L.

    2000-02-01

    A microfabrication process is described that provides for the batch realization of miniature rare earth based permanent magnets. Prismatic geometry with features as small as 5 microns, thicknesses up through several hundred microns and with submicron tolerances may be accommodated. The processing is based on a molding technique using deep x-ray lithography as a means to generate high aspect-ratio precision molds from PMMA (poly methyl methacrylate) used as an x-ray photoresist. Subsequent molding of rare-earth permanent magnet (REPM) powder combined with a thermosetting plastic binder may take place directly in the PMMA mold. Further approaches generate an alumina form replicated from the PMMA mold that becomes an intermediate mold for pressing higher density REPM material and allows for higher process temperatures. Maximum energy products of 3--8 MGOe (Mega Gauss Oersted, 1 MGOe = 100/4{pi} kJ/m{sup 3}) are obtained for bonded isotropic forms of REPM with dimensions on the scale of 100 microns and up to 23 MGOe for more dense anisotropic REPM material using higher temperature processing. The utility of miniature precision REPMs is revealed by the demonstration of a miniature multipole brushless DC motor that possesses a pole-anisotropic rotor with dimensions that would otherwise prohibit multipole magnetization using a multipole magnetizing fixture at this scale. Subsequent multipole assembly also leads to miniaturized Halbach arrays, efficient magnetic microactuators, and mechanical spring-like elements which can offset miniaturized mechanical scaling behavior.

  17. LDRD final report : chromophore-functionalized aligned carbon nanotube arrays.

    SciTech Connect

    Vance, Andrew L.; Yang, Chu-Yeu Peter; Krafcik, Karen Lee

    2011-09-01

    The goal of this project was to expand upon previously demonstrated single carbon nanotube devices by preparing a more practical, multi-single-walled carbon nanotube (SWNT) device. As a late-start, proof-of-concept project, the work focused on the fabrication and testing of chromophore-functionalized aligned SWNT field effect transistors (SWNT-FET). Such devices have not yet been demonstrated. The advantages of fabricating aligned SWNT devices include increased device cross-section to improve sensitivity to light, elimination of increased electrical resistance at nanotube junctions in random mat devices, and the ability to model device responses. The project did not achieve the goal of fabricating and testing chromophore-modified SWNT arrays, but a new SWNT growth capability was established that will benefit future projects. Although the ultimate goal of fabricating and testing chromophore-modified SWNT arrays was not achieved, the work did lead to a new carbon nanotube growth capability at Sandia/CA. The synthesis of dense arrays of horizontally aligned SWNTs is a developing area of research with significant potential for new discoveries. In particular, the ability to prepare arrays of carbon nanotubes of specific electronic types (metallic or semiconducting) could yield new classes of nanoscale devices.

  18. Population kinetics in dense plasmas

    SciTech Connect

    Schlanges, M.; Bornath, T.; Prenzel, R.; Kremp, D.

    1996-07-01

    Starting from quantum kinetic equations, rate equations for the number densities of the different atomic states and equations for the energy density are derived which are valid for dense nonideal plasmas. Statistical expressions are presented for the rate coefficients taking into account many-body effects as dynamical screening, lowering of the ionization energy and Pauli-blocking. Based on these generalized expressions, the coefficients of impact ionization, three-body recombination, excitation and deexcitation are calculated for nonideal hydrogen and carbon plasmas. As a result, higher ionization and recombination rates are obtained in the dense plasma region. The influence of the many-body effects on the population kinetics, including density and temperature relaxation, is shown then for a dense hydrogen plasma. {copyright} {ital 1996 American Institute of Physics.}

  19. Sandia SCADA Program -- High Surety SCADA LDRD Final Report

    SciTech Connect

    CARLSON, ROLF E.

    2002-04-01

    Supervisory Control and Data Acquisition (SCADA) systems are a part of the nation's critical infrastructure that is especially vulnerable to attack or disruption. Sandia National Laboratories is developing a high-security SCADA specification to increase the national security posture of the U.S. Because SCADA security is an international problem and is shaped by foreign and multinational interests, Sandia is working to develop a standards-based solution through committees such as the IEC TC 57 WG 15, the IEEE Substation Committee, and the IEEE P1547-related activity on communications and controls. The accepted standards are anticipated to take the form of a Common Criteria Protection Profile. This report provides the status of work completed and discusses several challenges ahead.

  20. Method for dense packing discovery

    NASA Astrophysics Data System (ADS)

    Kallus, Yoav; Elser, Veit; Gravel, Simon

    2010-11-01

    The problem of packing a system of particles as densely as possible is foundational in the field of discrete geometry and is a powerful model in the material and biological sciences. As packing problems retreat from the reach of solution by analytic constructions, the importance of an efficient numerical method for conducting de novo (from-scratch) searches for dense packings becomes crucial. In this paper, we use the divide and concur framework to develop a general search method for the solution of periodic constraint problems, and we apply it to the discovery of dense periodic packings. An important feature of the method is the integration of the unit-cell parameters with the other packing variables in the definition of the configuration space. The method we present led to previously reported improvements in the densest-known tetrahedron packing. Here, we use the method to reproduce the densest-known lattice sphere packings and the best-known lattice kissing arrangements in up to 14 and 11 dimensions, respectively, providing numerical evidence for their optimality. For nonspherical particles, we report a dense packing of regular four-dimensional simplices with density ϕ=128/219≈0.5845 and with a similar structure to the densest-known tetrahedron packing.

  1. FY08 LDRD Final Report A New Method for Wave Propagation in Elastic Media LDRD Project Tracking Code: 05-ERD-079

    SciTech Connect

    Petersson, A

    2009-01-29

    The LDRD project 'A New Method for Wave Propagation in Elastic Media' developed several improvements to the traditional finite difference technique for seismic wave propagation, including a summation-by-parts discretization which is provably stable for arbitrary heterogeneous materials, an accurate treatment of non-planar topography, local mesh refinement, and stable outflow boundary conditions. This project also implemented these techniques in a parallel open source computer code called WPP, and participated in several seismic modeling efforts to simulate ground motion due to earthquakes in Northern California. This research has been documented in six individual publications which are summarized in this report. Of these publications, four are published refereed journal articles, one is an accepted refereed journal article which has not yet been published, and one is a non-refereed software manual. The report concludes with a discussion of future research directions and exit plan.

  2. LDRD Final Report: Adaptive Methods for Laser Plasma Simulation

    SciTech Connect

    Dorr, M R; Garaizar, F X; Hittinger, J A

    2003-01-29

    The goal of this project was to investigate the utility of parallel adaptive mesh refinement (AMR) in the simulation of laser plasma interaction (LPI). The scope of work included the development of new numerical methods and parallel implementation strategies. The primary deliverables were (1) parallel adaptive algorithms to solve a system of equations combining plasma fluid and light propagation models, (2) a research code implementing these algorithms, and (3) an analysis of the performance of parallel AMR on LPI problems. The project accomplished these objectives. New algorithms were developed for the solution of a system of equations describing LPI. These algorithms were implemented in a new research code named ALPS (Adaptive Laser Plasma Simulator) that was used to test the effectiveness of the AMR algorithms on the Laboratory's large-scale computer platforms. The details of the algorithm and the results of the numerical tests were documented in an article published in the Journal of Computational Physics [2]. A principal conclusion of this investigation is that AMR is most effective for LPI systems that are ''hydrodynamically large'', i.e., problems requiring the simulation of a large plasma volume relative to the volume occupied by the laser light. Since the plasma-only regions require less resolution than the laser light, AMR enables the use of efficient meshes for such problems. In contrast, AMR is less effective for, say, a single highly filamented beam propagating through a phase plate, since the resulting speckle pattern may be too dense to adequately separate scales with a locally refined mesh. Ultimately, the gain to be expected from the use of AMR is highly problem-dependent. One class of problems investigated in this project involved a pair of laser beams crossing in a plasma flow. Under certain conditions, energy can be transferred from one beam to the other via a resonant interaction with an ion acoustic wave in the crossing region. AMR provides an

  3. Parallel Computation Chemistry Using Constraints: Final Report, LDRD 97-0301, Case 3504140000

    SciTech Connect

    Todd D. Plantenga

    1998-11-01

    Computer modeling to estimate material properties, design chem/bio sensors, and evaluate protein-protein interactions all require solving force field equations for molecular structures that contain tens of thousands of covalently connected atoms. Potential energy minimization is a key step in the calculation, but stiff covalent bonding forces make optimization difficult and expensive. This two-year LDRD developed two classes of advanced minimization algorithms that were specialized for chemistry applications and distributed computing machines. The project led to two successful algorithms that were implemented in three Sandia computational chemistry codes to support various users.

  4. Warm Dense Matter: An Overview

    SciTech Connect

    Kalantar, D H; Lee, R W; Molitoris, J D

    2004-04-21

    This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities. The conclusion of this

  5. Midpoint Shapes.

    ERIC Educational Resources Information Center

    Welchman, Rosamond; Urso, Josephine

    2000-01-01

    Emphasizes the importance of children exploring hands-on and minds-on mathematics. Presents a midpoint shape activity for students to explore the midpoint shape of familiar quadrilaterals, such as squares and rectangles. (KHR)

  6. Dense, finely, grained composite materials

    DOEpatents

    Dunmead, Stephen D.; Holt, Joseph B.; Kingman, Donald D.; Munir, Zuhair A.

    1990-01-01

    Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

  7. Dense periodic packings of tori

    NASA Astrophysics Data System (ADS)

    Gabbrielli, Ruggero; Jiao, Yang; Torquato, Salvatore

    2014-02-01

    Dense packings of nonoverlapping bodies in three-dimensional Euclidean space R3 are useful models of the structure of a variety of many-particle systems that arise in the physical and biological sciences. Here we investigate the packing behavior of congruent ring tori in R3, which are multiply connected nonconvex bodies of genus 1, as well as horn and spindle tori. Specifically, we analytically construct a family of dense periodic packings of unlinked tori guided by the organizing principles originally devised for simply connected solid bodies [22 Torquato and Jiao, Phys. Rev. E 86, 011102 (2012), 10.1103/PhysRevE.86.011102]. We find that the horn tori as well as certain spindle and ring tori can achieve a packing density not only higher than that of spheres (i.e., π /√18 =0.7404...) but also higher than the densest known ellipsoid packings (i.e., 0.7707...). In addition, we study dense packings of clusters of pair-linked ring tori (i.e., Hopf links), which can possess much higher densities than corresponding packings consisting of unlinked tori.

  8. Enhanced Vapor-Phase Diffusion in Porous Media - LDRD Final Report

    SciTech Connect

    Ho, C.K.; Webb, S.W.

    1999-01-01

    As part of the Laboratory-Directed Research and Development (LDRD) Program at Sandia National Laboratories, an investigation into the existence of enhanced vapor-phase diffusion (EVD) in porous media has been conducted. A thorough literature review was initially performed across multiple disciplines (soil science and engineering), and based on this review, the existence of EVD was found to be questionable. As a result, modeling and experiments were initiated to investigate the existence of EVD. In this LDRD, the first mechanistic model of EVD was developed which demonstrated the mechanisms responsible for EVD. The first direct measurements of EVD have also been conducted at multiple scales. Measurements have been made at the pore scale, in a two- dimensional network as represented by a fracture aperture, and in a porous medium. Significant enhancement of vapor-phase transport relative to Fickian diffusion was measured in all cases. The modeling and experimental results provide additional mechanisms for EVD beyond those presented by the generally accepted model of Philip and deVries (1957), which required a thermal gradient for EVD to exist. Modeling and experimental results show significant enhancement under isothermal conditions. Application of EVD to vapor transport in the near-surface vadose zone show a significant variation between no enhancement, the model of Philip and deVries, and the present results. Based on this information, the model of Philip and deVries may need to be modified, and additional studies are recommended.

  9. Multi-target camera tracking, hand-off and display LDRD 158819 final report

    SciTech Connect

    Anderson, Robert J.

    2014-10-01

    Modern security control rooms gather video and sensor feeds from tens to hundreds of cameras. Advanced camera analytics can detect motion from individual video streams and convert unexpected motion into alarms, but the interpretation of these alarms depends heavily upon human operators. Unfortunately, these operators can be overwhelmed when a large number of events happen simultaneously, or lulled into complacency due to frequent false alarms. This LDRD project has focused on improving video surveillance based security systems by changing the fundamental focus from the cameras to the targets being tracked. If properly integrated, more cameras shouldnt lead to more alarms, more monitors, more operators, and increased response latency but instead should lead to better information and more rapid response times. For the course of the LDRD we have been developing algorithms that takes live video imagery from multiple video cameras, identifies individual moving targets from the background imagery, and then displays the results in a single 3D interactive video. In this document we summarize the work in developing this multi-camera, multi-target system, including lessons learned, tools developed, technologies explored, and a description of currently capability.

  10. Multi-target camera tracking, hand-off and display LDRD 158819 final report.

    SciTech Connect

    Anderson, Robert J.

    2014-10-01

    Modern security control rooms gather video and sensor feeds from tens to hundreds of cameras. Advanced camera analytics can detect motion from individual video streams and convert unexpected motion into alarms, but the interpretation of these alarms depends heavily upon human operators. Unfortunately, these operators can be overwhelmed when a large number of events happen simultaneously, or lulled into complacency due to frequent false alarms. This LDRD project has focused on improving video surveillance based security systems by changing the fundamental focus from the cameras to the targets being tracked. If properly integrated, more cameras shouldnt lead to more alarms, more monitors, more operators, and increased response latency but instead should lead to better information and more rapid response times. For the course of the LDRD we have been developing algorithms that takes live video imagery from multiple video cameras, identifies individual moving targets from the background imagery, and then displays the results in a single 3D interactive video. In this document we summarize the work in developing this multi-camera, multi-target system, including lessons learned, tools developed, technologies explored, and a description of currently capability.

  11. Final report on LDRD project : coupling strategies for multi-physics applications.

    SciTech Connect

    Hopkins, Matthew Morgan; Moffat, Harry K.; Carnes, Brian; Hooper, Russell Warren; Pawlowski, Roger P.

    2007-11-01

    Many current and future modeling applications at Sandia including ASC milestones will critically depend on the simultaneous solution of vastly different physical phenomena. Issues due to code coupling are often not addressed, understood, or even recognized. The objectives of the LDRD has been both in theory and in code development. We will show that we have provided a fundamental analysis of coupling, i.e., when strong coupling vs. a successive substitution strategy is needed. We have enabled the implementation of tighter coupling strategies through additions to the NOX and Sierra code suites to make coupling strategies available now. We have leveraged existing functionality to do this. Specifically, we have built into NOX the capability to handle fully coupled simulations from multiple codes, and we have also built into NOX the capability to handle Jacobi Free Newton Krylov simulations that link multiple applications. We show how this capability may be accessed from within the Sierra Framework as well as from outside of Sierra. The critical impact from this LDRD is that we have shown how and have delivered strategies for enabling strong Newton-based coupling while respecting the modularity of existing codes. This will facilitate the use of these codes in a coupled manner to solve multi-physic applications.

  12. Validated modeling of distributed energy resources at distribution voltages : LDRD project 38672.

    SciTech Connect

    Ralph, Mark E.; Ginn, Jerry W.

    2004-03-01

    A significant barrier to the deployment of distributed energy resources (DER) onto the power grid is uncertainty on the part of utility engineers regarding impacts of DER on their distribution systems. Because of the many possible combinations of DER and local power system characteristics, these impacts can most effectively be studied by computer simulation. The goal of this LDRD project was to develop and experimentally validate models of transient and steady state source behavior for incorporation into utility distribution analysis tools. Development of these models had not been prioritized either by the distributed-generation industry or by the inverter industry. A functioning model of a selected inverter-based DER was developed in collaboration with both the manufacturer and industrial power systems analysts. The model was written in the PSCAD simulation language, a variant of the ElectroMagnetic Transients Program (EMTP), a code that is widely used and accepted by utilities. A stakeholder team was formed and a methodology was established to address the problem. A list of detailed DER/utility interaction concerns was developed and prioritized. The list indicated that the scope of the problem significantly exceeded resources available for this LDRD project. As this work progresses under separate funding, the model will be refined and experimentally validated. It will then be incorporated in utility distribution analysis tools and used to study a variety of DER issues. The key next step will be design of the validation experiments.

  13. MULTISCALE DISCRETIZATION OF SHAPE CONTOURS

    SciTech Connect

    Prasad, L.; Rao, R.

    2000-09-01

    We present an efficient multi-scale scheme to adaptively approximate the continuous (or densely sampled) contour of a planar shape at varying resolutions. The notion of shape is intimately related to the notion of contour, and the efficient representation of the contour of a shape is vital to a computational understanding of the shape. Any polygonal approximation of a planar smooth curve is equivalent to a piecewise constant approximation of the parameterized X and Y coordinate functions of a discrete point set obtained by densely sampling the curve. Using the Haar wavelet transform for the piecewise approximation yields a hierarchical scheme in which the size of the approximating point set is traded off against the morphological accuracy of the approximation. Our algorithm compresses the representation of the initial shape contour to a sparse sequence of points in the plane defining the vertices of the shape's polygonal approximation. Furthermore, it is possible to control the overall resolution of the approximation by a single, scale-independent parameter.

  14. Constructing Dense Graphs with Unique Hamiltonian Cycles

    ERIC Educational Resources Information Center

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  15. LANL LDRD-funded project: Test particle simulations of energetic ions in natural and artificial radiation belts

    SciTech Connect

    Cowee, Misa; Liu, Kaijun; Friedel, Reinhard H.; Reeves, Geoffrey D.

    2012-07-17

    We summarize the scientific problem and work plan for the LANL LDRD-funded project to use a test particle code to study the sudden de-trapping of inner belt protons and possible cross-L transport of debris ions after a high altitude nuclear explosion (HANE). We also discuss future application of the code for other HANE-related problems.

  16. Probing cold dense nuclear matter.

    PubMed

    Subedi, R; Shneor, R; Monaghan, P; Anderson, B D; Aniol, K; Annand, J; Arrington, J; Benaoum, H; Benmokhtar, F; Boeglin, W; Chen, J-P; Choi, Seonho; Cisbani, E; Craver, B; Frullani, S; Garibaldi, F; Gilad, S; Gilman, R; Glamazdin, O; Hansen, J-O; Higinbotham, D W; Holmstrom, T; Ibrahim, H; Igarashi, R; de Jager, C W; Jans, E; Jiang, X; Kaufman, L J; Kelleher, A; Kolarkar, A; Kumbartzki, G; Lerose, J J; Lindgren, R; Liyanage, N; Margaziotis, D J; Markowitz, P; Marrone, S; Mazouz, M; Meekins, D; Michaels, R; Moffit, B; Perdrisat, C F; Piasetzky, E; Potokar, M; Punjabi, V; Qiang, Y; Reinhold, J; Ron, G; Rosner, G; Saha, A; Sawatzky, B; Shahinyan, A; Sirca, S; Slifer, K; Solvignon, P; Sulkosky, V; Urciuoli, G M; Voutier, E; Watson, J W; Weinstein, L B; Wojtsekhowski, B; Wood, S; Zheng, X-C; Zhu, L

    2008-06-13

    The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars. PMID:18511658

  17. Probing Cold Dense Nuclear Matter

    SciTech Connect

    Subedi, Ramesh; Shneor, R.; Monaghan, Peter; Anderson, Bryon; Aniol, Konrad; Annand, John; Arrington, John; Benaoum, Hachemi; Benmokhtar, Fatiha; Bertozzi, William; Boeglin, Werner; Chen, Jian-Ping; Choi, Seonho; Cisbani, Evaristo; Craver, Brandon; Frullani, Salvatore; Garibaldi, Franco; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Ibrahim, Hassan; Igarashi, Ryuichi; De Jager, Cornelis; Jans, Eddy; Jiang, Xiaodong; Kaufman, Lisa; Kelleher, Aidan; Kolarkar, Ameya; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Mazouz, Malek; Meekins, David; Michaels, Robert; Moffit, Bryan; Perdrisat, Charles; Piasetzky, Eliazer; Potokar, Milan; Punjabi, Vina; Qiang, Yi; Reinhold, Joerg; Ron, Guy; Rosner, Guenther; Saha, Arunava; Sawatzky, Bradley; Shahinyan, Albert; Sirca, Simon; Slifer, Karl; Solvignon, Patricia; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Urciuoli, Guido; Voutier, Eric; Watson, John; Weinstein, Lawrence; Wojtsekhowski, Bogdan; Wood, Stephen; Zheng, Xiaochao; Zhu, Lingyan

    2008-06-01

    The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.

  18. Exploring pulse shaping for Z using graded-density impactors on gas guns (final report for LDRD project 79879).

    SciTech Connect

    Furnish, Michael David; Reinhart, William Dodd; Anderson, William W. (Los Alamos National Laboratory, Los Alamos, NM); Vogler, Tracy John; Hixson, Rob (Los Alamos National Laboratory, Los Alamos, NM); Kipp, Marlin E.

    2005-10-01

    While isentropic compression experiment (ICE) techniques have proved useful in deducing the high-pressure compressibility of a wide range of materials, they have encountered difficulties where large-volume phase transitions exist. The present study sought to apply graded-density impactor methods for producing isentropic loading to planar impact experiments to selected such problems. Cerium was chosen due to its 20% compression between 0.7 and 1.0 GPa. A model was constructed based on limited earlier dynamic data, and applied to the design of a suite of experiments. A capability for handling this material was installed. Two experiments were executed using shock/reload techniques with available samples, loading initially to near the gamma-alpha transition, then reloading. As well, two graded-density impactor experiments were conducted with alumina. A method for interpreting ICE data was developed and validated; this uses a wavelet construction for the ramp wave and includes corrections for the ''diffraction'' of wavelets by releases or reloads reflected from the sample/window interface. Alternate methods for constructing graded-density impactors are discussed.

  19. Magnetism in Dense Quark Matter

    NASA Astrophysics Data System (ADS)

    Ferrer, Efrain J.; de la Incera, Vivian

    We review the mechanisms via which an external magnetic field can affect the ground state of cold and dense quark matter. In the absence of a magnetic field, at asymptotically high densities, cold quark matter is in the Color-Flavor-Locked (CFL) phase of color superconductivity characterized by three scales: the superconducting gap, the gluon Meissner mass, and the baryonic chemical potential. When an applied magnetic field becomes comparable with each of these scales, new phases and/or condensates may emerge. They include the magnetic CFL (MCFL) phase that becomes relevant for fields of the order of the gap scale; the paramagnetic CFL, important when the field is of the order of the Meissner mass, and a spin-one condensate associated to the magnetic moment of the Cooper pairs, significant at fields of the order of the chemical potential. We discuss the equation of state (EoS) of MCFL matter for a large range of field values and consider possible applications of the magnetic effects on dense quark matter to the astrophysics of compact stars.

  20. Microchannel cross load array with dense parallel input

    DOEpatents

    Swierkowski, Stefan P.

    2004-04-06

    An architecture or layout for microchannel arrays using T or Cross (+) loading for electrophoresis or other injection and separation chemistry that are performed in microfluidic configurations. This architecture enables a very dense layout of arrays of functionally identical shaped channels and it also solves the problem of simultaneously enabling efficient parallel shapes and biasing of the input wells, waste wells, and bias wells at the input end of the separation columns. One T load architecture uses circular holes with common rows, but not columns, which allows the flow paths for each channel to be identical in shape, using multiple mirror image pieces. Another T load architecture enables the access hole array to be formed on a biaxial, collinear grid suitable for EDM micromachining (square holes), with common rows and columns.

  1. Earthquake source inversion with dense networks

    NASA Astrophysics Data System (ADS)

    Somala, S.; Ampuero, J. P.; Lapusta, N.

    2012-12-01

    Inversions of earthquake source slip from the recorded ground motions typically impose a number of restrictions on the source parameterization, which are needed to stabilize the inverse problem with sparse data. Such restrictions may include smoothing, causality considerations, predetermined shapes of the local source-time function, and constant rupture speed. The goal of our work is to understand whether the inversion results could be substantially improved by the availability of much denser sensor networks than currently available. The best regional networks have sensor spacing in the tens of kilometers range, much larger than the wavelengths relevant to key aspects of earthquake physics. Novel approaches to providing orders-of-magnitude denser sensing include low-cost sensors (Community Seismic Network) and space-based optical imaging (Geostationary Optical Seismometer). However, in both cases, the density of sensors comes at the expense of accuracy. Inversions that involve large number of sensors are intractable with the current source inversion codes. Hence we are developing a new approach that can handle thousands of sensors. It employs iterative conjugate gradient optimization based on an adjoint method and involves iterative time-reversed 3D wave propagation simulations using the spectral element method (SPECFEM3D). To test the developed method, and to investigate the effect of sensor density and quality on the inversion results, we have been considering kinematic and dynamic synthetic sources of several types: one or more Haskell pulses with various widths and spacings; scenarios with local rupture propagation in the opposite direction (as observed during the 2010 El Mayor-Cucapah earthquake); dynamic crack-like rupture, both subshear and supershear; and rupture that mimics supershear propagation by jumping along the fault. In each case, we produce the data by a forward SPECFEM3D calculation, choose the desired density of stations, filter the data to 1 Hz

  2. Schapiro Shapes

    ERIC Educational Resources Information Center

    O'Connell, Emily

    2009-01-01

    This article describes a lesson on Schapiro Shapes. Schapiro Shapes is based on the art of Miriam Schapiro, who created a number of works of figures in action. Using the basic concepts of this project, students learn to create their own figures and styles. (Contains 1 online resource.)

  3. Multiscale characterization and analysis of shapes

    DOEpatents

    Prasad, Lakshman; Rao, Ramana

    2002-01-01

    An adaptive multiscale method approximates shapes with continuous or uniformly and densely sampled contours, with the purpose of sparsely and nonuniformly discretizing the boundaries of shapes at any prescribed resolution, while at the same time retaining the salient shape features at that resolution. In another aspect, a fundamental geometric filtering scheme using the Constrained Delaunay Triangulation (CDT) of polygonized shapes creates an efficient parsing of shapes into components that have semantic significance dependent only on the shapes' structure and not on their representations per se. A shape skeletonization process generalizes to sparsely discretized shapes, with the additional benefit of prunability to filter out irrelevant and morphologically insignificant features. The skeletal representation of characters of varying thickness and the elimination of insignificant and noisy spurs and branches from the skeleton greatly increases the robustness, reliability and recognition rates of character recognition algorithms.

  4. Oblique impact of dense granular sheets

    NASA Astrophysics Data System (ADS)

    Ellowitz, Jake; Guttenberg, Nicholas; Jaeger, Heinrich M.; Nagel, Sidney R.; Zhang, Wendy W.

    2013-11-01

    Motivated by experiments showing impacts of granular jets with non-circular cross sections produce thin ejecta sheets with anisotropic shapes, we study what happens when two sheets containing densely packed, rigid grains traveling at the same speed collide asymmetrically. Discrete particle simulations and a continuum frictional fluid model yield the same steady-state solution of two exit streams emerging from incident streams. When the incident angle Δθ is less than Δθc =120° +/-10° , the exit streams' angles differ from that measured in water sheet experiments. Below Δθc , the exit angles from granular and water sheet impacts agree. This correspondence is surprising because 2D Euler jet impact, the idealization relevant for both situations, is ill posed: a generic Δθ value permits a continuous family of solutions. Our finding that granular and water sheet impacts evolve into the same member of the solution family suggests previous proposals that perturbations such as viscous drag, surface tension or air entrapment select the actual outcome are not correct. Currently at Department of Physics, University of Oregon, Eugene, OR 97403.

  5. The lifetime of evaporating dense sprays

    NASA Astrophysics Data System (ADS)

    de Rivas, Alois; Villermaux, Emmanuel

    2015-11-01

    We study the processes by which a set of nearby liquid droplets (a spray) evaporates in a gas phase whose relative humidity (vapor concentration) is controlled at will. A dense spray of micron-sized water droplets is formed in air by a pneumatic atomizer and conveyed through a nozzle in a closed chamber whose vapor concentration has been pre-set to a controlled value. The resulting plume extension depends on the relative humidity of the diluting medium. When the spray plume is straight and laminar, droplets evaporate at its edge where the vapor is saturated, and diffuses through a boundary layer developing around the plume. We quantify the shape and length of the plume as a function of the injecting, vapor diffusion, thermodynamic and environment parameters. For higher injection Reynolds numbers, standard shear instabilities distort the plume into stretched lamellae, thus enhancing the diffusion of vapor from their boundary towards the diluting medium. These lamellae vanish in a finite time depending on the intensity of the stretching, and relative humidity of the environment, with a lifetime diverging close to the equilibrium limit, when the plume develops in an medium saturated in vapor. The dependences are described quantitatively.

  6. Dense Plasma X-ray Scattering: Methods and Applications

    SciTech Connect

    Glenzer, S H; Lee, H J; Davis, P; Doppner, T; Falcone, R W; Fortmann, C; Hammel, B A; Kritcher, A L; Landen, O L; Lee, R W; Munro, D H; Redmer, R; Weber, S

    2009-08-19

    We have developed accurate x-ray scattering techniques to measure the physical properties of dense plasmas. Temperature and density are inferred from inelastic x-ray scattering data whose interpretation is model-independent for low to moderately coupled systems. Specifically, the spectral shape of the non-collective Compton scattering spectrum directly reflects the electron velocity distribution. In partially Fermi degenerate systems that have been investigated experimentally in laser shock-compressed beryllium, the Compton scattering spectrum provides the Fermi energy and hence the electron density. We show that forward scattering spectra that observe collective plasmon oscillations yield densities in agreement with Compton scattering. In addition, electron temperatures inferred from the dispersion of the plasmon feature are consistent with the ion temperature sensitive elastic scattering feature. Hence, theoretical models of the static ion-ion structure factor and consequently the equation of state of dense matter can be directly tested.

  7. Bioagent detection using miniaturized NMR and nanoparticle amplification : final LDRD report.

    SciTech Connect

    Clewett, C. F. M.; Adams, David Price; Fan, Hongyou; Williams, John D.; Sillerud, Laurel O.; Alam, Todd Michael; Aldophi, Natalie L. (New Mexico Resonance, Albuquerque, NM); McDowell, Andrew F.

    2006-11-01

    This LDRD program was directed towards the development of a portable micro-nuclear magnetic resonance ({micro}-NMR) spectrometer for the detection of bioagents via induced amplification of solvent relaxation based on superparamagnetic nanoparticles. The first component of this research was the fabrication and testing of two different micro-coil ({micro}-coil) platforms: namely a planar spiral NMR {micro}-coil and a cylindrical solenoid NMR {micro}-coil. These fabrication techniques are described along with the testing of the NMR performance for the individual coils. The NMR relaxivity for a series of water soluble FeMn oxide nanoparticles was also determined to explore the influence of the nanoparticle size on the observed NMR relaxation properties. In addition, The use of commercially produced superparamagnetic iron oxide nanoparticles (SPIONs) for amplification via NMR based relaxation mechanisms was also demonstrated, with the lower detection limit in number of SPIONs per nanoliter (nL) being determined.

  8. LDRD final report: Physical simulation of nonisothermal multiphase multicomponent flow in porous media

    SciTech Connect

    Martinez, M.J.; Hopkins, P.L.; Shadid, J.N.

    1997-07-01

    This document reports on the accomplishments of a laboratory-directed research and development (LDRD) project whose objective was to initiate a research program for developing a fundamental understanding of multiphase multicomponent subsurface transport in heterogeneous porous media and to develop parallel processing computational tools for numerical simulation of such problems. The main achievement of this project was the successful development of a general-purpose, unstructured grid, multiphase thermal simulator for subsurface transport in heterogeneous porous media implemented for use on massively parallel (MP) computers via message-passing and domain decomposition techniques. The numerical platform provides an excellent base for new and continuing project development in areas of current interest to SNL and the DOE complex including, subsurface nuclear waste disposal and cleanup, groundwater availability and contamination studies, fuel-spill transport for accident analysis, and DNAPL transport and remediation.

  9. Final LDRD report : development of advanced UV light emitters and biological agent detection strategies.

    SciTech Connect

    Figiel, Jeffrey James; Crawford, Mary Hagerott; Banas, Michael Anthony; Farrow, Darcie; Armstrong, Andrew M.; Serkland, Darwin Keith; Allerman, Andrew Alan; Schmitt, Randal L.

    2007-12-01

    We present the results of a three year LDRD project which has focused on the development of novel, compact, ultraviolet solid-state sources and fluorescence-based sensing platforms that apply such devices to the sensing of biological and nuclear materials. We describe our development of 270-280 nm AlGaN-based semiconductor UV LEDs with performance suitable for evaluation in biosensor platforms as well as our development efforts towards the realization of a 340 nm AlGaN-based laser diode technology. We further review our sensor development efforts, including evaluation of the efficacy of using modulated LED excitation and phase sensitive detection techniques for fluorescence detection of bio molecules and uranyl-containing compounds.

  10. Final report on LDRD project: Simulation/optimization tools for system variability analysis

    SciTech Connect

    R. L. Bierbaum; R. F. Billau; J. E. Campbell; K. D. Marx; R. J. Sikorski; B. M. Thompson; S. D. Wix

    1999-10-01

    >This work was conducted during FY98 (Proposal Number 98-0036) and FY99 (Proposal Number 99-0818) under the auspices of the Sandia National Laboratories Laboratory-Directed Research and Development (LDRD) program. Electrical simulation typically treats a single data point in the very large input space of component properties. For electrical simulation to reach its full potential as a design tool, it must be able to address the unavoidable variability and uncertainty in component properties. Component viability is strongly related to the design margin (and reliability) of the end product. During the course of this project, both tools and methodologies were developed to enable analysis of variability in the context of electrical simulation tools. Two avenues to link relevant tools were also developed, and the resultant toolset was applied to a major component.

  11. LDRD final report : a lightweight operating system for multi-core capability class supercomputers.

    SciTech Connect

    Kelly, Suzanne Marie; Hudson, Trammell B.; Ferreira, Kurt Brian; Bridges, Patrick G.; Pedretti, Kevin Thomas Tauke; Levenhagen, Michael J.; Brightwell, Ronald Brian

    2010-09-01

    The two primary objectives of this LDRD project were to create a lightweight kernel (LWK) operating system(OS) designed to take maximum advantage of multi-core processors, and to leverage the virtualization capabilities in modern multi-core processors to create a more flexible and adaptable LWK environment. The most significant technical accomplishments of this project were the development of the Kitten lightweight kernel, the co-development of the SMARTMAP intra-node memory mapping technique, and the development and demonstration of a scalable virtualization environment for HPC. Each of these topics is presented in this report by the inclusion of a published or submitted research paper. The results of this project are being leveraged by several ongoing and new research projects.

  12. Final LDRD report :ultraviolet water purification systems for rural environments and mobile applications.

    SciTech Connect

    Banas, Michael Anthony; Crawford, Mary Hagerott; Ruby, Douglas Scott; Ross, Michael P.; Nelson, Jeffrey Scott; Allerman, Andrew Alan; Boucher, Ray

    2005-11-01

    We present the results of a one year LDRD program that has focused on evaluating the use of newly developed deep ultraviolet LEDs in water purification. We describe our development efforts that have produced an LED-based water exposure set-up and enumerate the advances that have been made in deep UV LED performance throughout the project. The results of E. coli inactivation with 270-295 nm LEDs are presented along with an assessment of the potential for applying deep ultraviolet LED-based water purification to mobile point-of-use applications as well as to rural and international environments where the benefits of photovoltaic-powered systems can be realized.

  13. Nanoporous films for epitaxial growth of single crystal semiconductor materials : final LDRD report.

    SciTech Connect

    Rowen, Adam M.; Koleske, Daniel David; Fan, Hongyou; Brinker, C. Jeffrey; Burckel, David Bruce; Williams, John Dalton; Arrington, Christian L.; Steen, William Arthur

    2007-10-01

    This senior council Tier 1 LDRD was focused on exploring the use of porous growth masks as a method for defect reduction during heteroepitaxial crystal growth. Initially our goal was to investigate porous silica as a growth mask, however, we expanded the scope of the research to include several other porous growth masks on various size scales, including mesoporous carbon, photolithographically patterned SU-8 and carbonized SU-8 structures. Use of photolithographically defined growth templates represents a new direction, unique in the extensive literature of patterned epitaxial growth, and presents the possibility of providing a single step growth mask. Additional research included investigation of pore viability via electrochemical deposition into high aspect ratio photoresist. This project was a small footprint research effort which, nonetheless, produced significant progress towards both the stated goal as well as unanticipated research directions.

  14. Terahertz spectral signatures :measurement and detection LDRD project 86361 final report.

    SciTech Connect

    Wanke, Michael Clement; Brener, Igal; Lee, Mark

    2005-11-01

    LDRD Project 86361 provided support to upgrade the chemical and material spectral signature measurement and detection capabilities of Sandia National Laboratories using the terahertz (THz) portion of the electromagnetic spectrum, which includes frequencies between 0.1 to 10 THz. Under this project, a THz time-domain spectrometer was completed. This instrument measures sample absorption spectra coherently, obtaining both magnitude and phase of the absorption signal, and has shown an operating signal-to-noise ratio of 10{sub 4}. Additionally, various gas cells and a reflectometer were added to an existing high-resolution THz Fourier transform spectrometer, which greatly extend the functionality of this spectrometer. Finally, preliminary efforts to design an integrated THz transceiver based on a quantum cascade laser were begun.

  15. Transmissive infrared frequency selective surfaces and infrared antennas : final report for LDRD 105749.

    SciTech Connect

    Wendt, Joel Robert; Hadley, G. Ronald; Samora, Sally; Loui, Hung; Cruz-Cabrera, Alvaro Augusto; Davids, Paul; Kemme, Shanalyn A.; Basilio, Lorena I.; Johnson, William Arthur; Peters, David William

    2009-09-01

    Plasmonic structures open up new opportunities in photonic devices, sometimes offering an alternate method to perform a function and sometimes offering capabilities not possible with standard optics. In this LDRD we successfully demonstrated metal coatings on optical surfaces that do not adversely affect the transmission of those surfaces at the design frequency. This technology could be applied as an RF noise blocking layer across an optical aperture or as a method to apply an electric field to an active electro-optic device without affecting optical performance. We also demonstrated thin optical absorbers using similar patterned surfaces. These infrared optical antennas show promise as a method to improve performance in mercury cadmium telluride detectors. Furthermore, these structures could be coupled with other components to lead to direct rectification of infrared radiation. This possibility leads to a new method for infrared detection and energy harvesting of infrared radiation.

  16. Final report on LDRD Project: Quantum confinement and light emission in silicon nanostructures

    SciTech Connect

    Guilinger, T.R.; Kelly, M.J.; Follstaedt, D.M.

    1995-02-01

    Electrochemically formed porous silicon (PS) was reported in 1991 to exhibit visible photoluminescence. This discovery could lead to the use of integrated silicon-based optoelectronic devices. This LDRD addressed two general goals for optical emission from Si: (1) investigate the mechanisms responsible for light emission, and (2) tailor the microstructure and composition of the Si to obtain photoemission suitable for working devices. PS formation, composition, morphology, and microstructure have been under investigation at Sandia for the past ten years for applications in silicon-on-insulator microelectronics, micromachining, and chemical sensors. The authors used this expertise to form luminescent PS at a variety of wavelengths and have used analytical techniques such as in situ Raman and X-ray reflectivity to investigate the luminescence mechanism and quantify the properties of the porous silicon layer. Further, their experience with ion implantation in Si lead to an investigation into alternate methods of producing Si nanostructures that visibly luminesce.

  17. Main group adducts of carbon dioxide and related chemistry (LDRD 149938).

    SciTech Connect

    Barry, Brian M.; Kemp, Richard Alan; Stewart, Constantine A.; Dickie, Diane A.

    2010-11-01

    This late-start LDRD was broadly focused on the synthetic attempts to prepare novel ligands as complexing agents for main group metals for the sequestration of CO{sub 2}. In prior work we have shown that certain main group (p block elements) metals such as tin and zinc, when ligated to phosphinoamido- ligands, can bind CO{sub 2} in a novel fashion. Rather than simple insertion into the metal-nitrogen bonds to form carbamates, we have seen the highly unusual complexation of CO{sub 2} in a mode that is more similar to a chemical 'adduct' rather than complexation schemes that have been observed previously. The overarching goal in this work is to prepare more of these complexes that can (a) sequester (or bind) CO{sub 2} easily in this adduct form, and (b) be stable to chemical or electrochemical reduction designed to convert the CO{sub 2} to useful fuels or fuel precursors. The currently used phosphinoamido- ligands appear at this point to be less-stable than desired under electrochemical reduction conditions. This instability is believed due to the more delicate, reactive nature of the ligand framework system. In order to successfully capture and convert CO{sub 2} to useful organics, this instability must be addressed and solved. Work described in the late-start LDRD was designed to screen a variety of ligand/metal complexes that a priori are believed to be more stable to polar solvents and possible mild hydrolytic conditions than are the phosphinoamido-ligands. Results from ligand syntheses and metal complexation studies are reported.

  18. Quantum Cascade Lasers (QCLs) for standoff explosives detection : LDRD 138733 final report.

    SciTech Connect

    Theisen, Lisa Anne; Linker, Kevin Lane

    2009-09-01

    Continued acts of terrorism using explosive materials throughout the world have led to great interest in explosives detection technology, especially technologies that have a potential for remote or standoff detection. This LDRD was undertaken to investigate the benefit of the possible use of quantum cascade lasers (QCLs) in standoff explosives detection equipment. Standoff detection of explosives is currently one of the most difficult problems facing the explosives detection community. Increased domestic and troop security could be achieved through the remote detection of explosives. An effective remote or standoff explosives detection capability would save lives and prevent losses of mission-critical resources by increasing the distance between the explosives and the intended targets and/or security forces. Many sectors of the US government are urgently attempting to obtain useful equipment to deploy to our troops currently serving in hostile environments. This LDRD was undertaken to investigate the potential benefits of utilizing quantum cascade lasers (QCLs) in standoff detection systems. This report documents the potential opportunities that Sandia National Laboratories can contribute to the field of QCL development. The following is a list of areas where SNL can contribute: (1) Determine optimal wavelengths for standoff explosives detection utilizing QCLs; (2) Optimize the photon collection and detection efficiency of a detection system for optical spectroscopy; (3) Develop QCLs with broader wavelength tunability (current technology is a 10% change in wavelength) while maintaining high efficiency; (4) Perform system engineering in the design of a complete detection system and not just the laser head; and (5) Perform real-world testing with explosive materials with commercial prototype detection systems.

  19. Discovering dense and consistent landmarks in the brain.

    PubMed

    Zhu, Dajiang; Zhang, Degang; Faraco, Carlos; Li, Kaiming; Deng, Fan; Chen, Hanbo; Jiang, Xi; Guo, Lei; Miller, L Stephen; Liu, Tianming

    2011-01-01

    The lack of consistent and reliable functionally meaningful landmarks in the brain has significantly hampered the advancement of brain imaging studies. In this paper, we use white matter fiber connectivity patterns, obtained from diffusion tensor imaging (DTI) data, as predictors of brain function, and to discover a dense, reliable and consistent map of brain landmarks within and across individuals. The general principles and our strategies are as follows. 1) Each brain landmark should have consistent structural fiber connectivity pattern across a group of subjects. We will quantitatively measure the similarity of the fiber bundles emanating from the corresponding landmarks via a novel trace-map approach, and then optimize the locations of these landmarks by maximizing the group-wise consistency of the shape patterns of emanating fiber bundles. 2) The landmark map should be dense and distributed all over major functional brain regions. We will initialize a dense and regular grid map of approximately 2000 landmarks that cover the whole brains in different subjects via linear brain image registration. 3) The dense map of brain landmarks should be reproducible and predictable in different datasets of various subject populations. The approaches and results in the above two steps are evaluated and validated via reproducibility studies. The dense map of brain landmarks can be reliably and accurately replicated in a new DTI dataset such that the landmark map can be used as a predictive model. Our experiments show promising results, and a subset of the discovered landmarks are validated via task-based fMRI. PMID:21761649

  20. Uniformly dense polymeric foam body

    DOEpatents

    Whinnery, Jr., Leroy

    2003-07-15

    A method for providing a uniformly dense polymer foam body having a density between about 0.013 g/cm.sup.3 to about 0.5 g/cm.sup.3 is disclosed. The method utilizes a thermally expandable polymer microsphere material wherein some of the microspheres are unexpanded and some are only partially expanded. It is shown that by mixing the two types of materials in appropriate ratios to achieve the desired bulk final density, filling a mold with this mixture so as to displace all or essentially all of the internal volume of the mold, heating the mold for a predetermined interval at a temperature above about 130.degree. C., and then cooling the mold to a temperature below 80.degree. C. the molded part achieves a bulk density which varies by less then about .+-.6% everywhere throughout the part volume.

  1. DPIS for warm dense matter

    SciTech Connect

    Kondo, K.; Kanesue, T.; Horioka, K.; Okamura, M.

    2010-05-23

    Warm Dense Matter (WDM) offers an challenging problem because WDM, which is beyond ideal plasma, is in a low temperature and high density state with partially degenerate electrons and coupled ions. WDM is a common state of matter in astrophysical objects such as cores of giant planets and white dwarfs. The WDM studies require large energy deposition into a small target volume in a shorter time than the hydrodynamical time and need uniformity across the full thickness of the target. Since moderate energy ion beams ({approx} 0.3 MeV/u) can be useful tool for WDM physics, we propose WDM generation using Direct Plasma Injection Scheme (DPIS). In the DPIS, laser ion source is connected to the Radio Frequency Quadrupole (RFQ) linear accelerator directly without the beam transport line. DPIS with a realistic final focus and a linear accelerator can produce WDM.

  2. Dense inhibitory connectivity in neocortex

    PubMed Central

    Fino, Elodie; Yuste, Rafael

    2011-01-01

    Summary The connectivity diagram of neocortical circuits is still unknown, and there are conflicting data as to whether cortical neurons are wired specifically or not. To investigate the basic structure of cortical microcircuits, we use a novel two-photon photostimulation technique that enables the systematic mapping of synaptic connections with single-cell resolution. We map the inhibitory connectivity between upper layers somatostatin-positive GABAergic interneurons and pyramidal cells in mouse frontal cortex. Most, and sometimes all, inhibitory neurons are locally connected to every sampled pyramidal cell. This dense inhibitory connectivity is found at both young and mature developmental ages. Inhibitory innervation of neighboring pyramidal cells is similar, regardless of whether they are connected among themselves or not. We conclude that local inhibitory connectivity is promiscuous, does not form subnetworks and can approach the theoretical limit of a completely connected synaptic matrix. PMID:21435562

  3. Viscoelastic behavior of dense microemulsions

    NASA Astrophysics Data System (ADS)

    Cametti, C.; Codastefano, P.; D'arrigo, G.; Tartaglia, P.; Rouch, J.; Chen, S. H.

    1990-09-01

    We have performed extensive measurements of shear viscosity, ultrasonic absorption, and sound velocity in a ternary system consisting of water-decane-sodium di(2-ethylhexyl)sulfo- succinate(AOT), in the one-phase region where it forms a water-in-oil microemulsion. We observe a rapid increase of the static shear viscosity in the dense microemulsion region. Correspondingly the sound absorption shows unambiguous evidence of a viscoelastic behavior. The absorption data for various volume fractions and temperatures can be reduced to a universal curve by scaling both the absorption and the frequency by the measured static shear viscosity. The sound absorption can be interpreted as coming from the high-frequency tail of the viscoelastic relaxation, describable by a Cole-Cole relaxation formula with unusually small elastic moduli.

  4. The performance of dense medium processes

    SciTech Connect

    Horsfall, D.W.

    1993-12-31

    Dense medium washing in baths and cyclones is widely carried out in South Africa. The paper shows the reason for the preferred use of dense medium processes rather than gravity concentrators such as jigs. The factors leading to efficient separation in baths are listed and an indication given of the extent to which these factors may be controlled and embodied in the deployment of baths and dense medium cyclones in the planning stages of a plant.

  5. Final LDRD Report for Projects %23 52797 and %23 93362: Rational Understanding and Control of the Magnetic Behavior of Nanoparticles.

    SciTech Connect

    Zhang, Z. John

    2006-11-01

    This is the final LDRD report for projects %23 52797 and %23 93362 that funded a five year research program directed by Prof. Z. John Zhang at the Georgia Institute of Technology Chemistry Department. Prof. Zhang was awarded this funding after winning a Presidential Early Career Award in Science and Engineering (PECASE) in 2001 with Sandia as the DOE sponsoring lab. The project PI was Blake Simmons and the PM was Alfredo Morales. The page intentionally left blank

  6. Percolation in dense storage arrays

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Scott; Wilcke, Winfried W.; Garner, Robert B.; Huels, Harald

    2002-11-01

    As computers and their accessories become smaller, cheaper, and faster the providers of news, retail sales, and other services we now take for granted on the Internet have met their increasing computing needs by putting more and more computers, hard disks, power supplies, and the data communications linking them to each other and to the rest of the wired world into ever smaller spaces. This has created a new and quite interesting percolation problem. It is no longer desirable to fix computers, storage or switchgear which fail in such a dense array. Attempts to repair things are all too likely to make problems worse. The alternative approach, letting units “fail in place”, be removed from service and routed around, means that a data communications environment will evolve with an underlying regular structure but a very high density of missing pieces. Some of the properties of this kind of network can be described within the existing paradigm of site or bond percolation on lattices, but other important questions have not been explored. I will discuss 3D arrays of hundreds to thousands of storage servers (something which it is quite feasible to build in the next few years), and show that bandwidth, but not percolation fraction or shortest path lengths, is the critical factor affected by the “fail in place” disorder. Redundancy strategies traditionally employed in storage systems may have to be revised. Novel approaches to routing information among the servers have been developed to minimize the impact.

  7. Geophysical Age Dating of Seamounts using Dense Core Flexure Model

    NASA Astrophysics Data System (ADS)

    Hwang, Gyuha; Kim, Seung-Sep

    2016-04-01

    Lithospheric flexure of oceanic plate is thermo-mechanical response of an elastic plate to the given volcanic construct (e.g., seamounts and ocean islands). If the shape and mass of such volcanic loads are known, the flexural response is governed by the thickness of elastic plate, Te. As the age of oceanic plate increases, the elastic thickness of oceanic lithosphere becomes thicker. Thus, we can relate Te with the age of plate at the time of loading. To estimate the amount of the driving force due to seamounts on elastic plate, one needs to approximate their density structure. The most common choice is uniform density model, which utilizes constant density value for a seamount. This approach simplifies computational processes for gravity prediction and error estimates. However, the uniform density model tends to overestimate the total mass of the seamount and hence produces more positive gravitational contributions from the load. Minimization of gravity misfits using uniform density, therefore, favors thinner Te in order to increase negative contributions from the lithospheric flexure, which can compensate for the excessive positives from the seamount. An alternative approach is dense core model, which approximate the heterogeneity nature of seamount density as three bodies of infill sediment, edifice, and dense core. In this study, we apply the dense core model to the Louisville Seamount Chain for constraining flexural deformation. We compare Te estimates with the loading time of the examined seamounts to redefine empirical geophysical age dating of seamounts.

  8. Filtered Rayleigh scattering diagnostic for multi-parameter thermal-fluids measurements : LDRD final report.

    SciTech Connect

    Beresh, Steven Jay; Grasser, Thomas W.; Kearney, Sean Patrick; Schefer, Robert W.

    2004-01-01

    Simulation-based life-cycle-engineering and the ASCI program have resulted in models of unprecedented size and fidelity. The validation of these models requires high-resolution, multi-parameter diagnostics. Within the thermal-fluids disciplines, the need for detailed, high-fidelity measurements exceeds the limits of current engineering sciences capabilities and severely tests the state of the art. The focus of this LDRD is the development and application of filtered Rayleigh scattering (FRS) for high-resolution, nonintrusive measurement of gas-phase velocity and temperature. With FRS, the flow is laser-illuminated and Rayleigh scattering from naturally occurring sources is detected through a molecular filter. The filtered transmission may be interpreted to yield point or planar measurements of three-component velocities and/or thermodynamic state. Different experimental configurations may be employed to obtain compromises between spatial resolution, time resolution, and the quantity of simultaneously measured flow variables. In this report, we present the results of a three-year LDRD-funded effort to develop FRS combustion thermometry and Aerosciences velocity measurement systems. The working principles and details of our FRS opto-electronic system are presented in detail. For combustion thermometry we present 2-D, spatially correlated FRS results from nonsooting premixed and diffusion flames and from a sooting premixed flame. The FRS-measured temperatures are accurate to within {+-}50 K (3%) in a premixed CH4-air flame and within {+-}100 K for a vortex-strained diluted CH4-air diffusion flame where the FRS technique is severely tested by large variation in scattering cross section. In the diffusion flame work, FRS has been combined with Raman imaging of the CH4 fuel molecule to correct for the local light scattering properties of the combustion gases. To our knowledge, this is the first extension of FRS to nonpremixed combustion and the first use of joint FRS

  9. Advancements in sensing and perception using structured lighting techniques :an LDRD final report.

    SciTech Connect

    Novick, David Keith; Padilla, Denise D.; Davidson, Patrick A. Jr.; Carlson, Jeffrey J.

    2005-09-01

    This report summarizes the analytical and experimental efforts for the Laboratory Directed Research and Development (LDRD) project entitled ''Advancements in Sensing and Perception using Structured Lighting Techniques''. There is an ever-increasing need for robust, autonomous ground vehicles for counterterrorism and defense missions. Although there has been nearly 30 years of government-sponsored research, it is undisputed that significant advancements in sensing and perception are necessary. We developed an innovative, advanced sensing technology for national security missions serving the Department of Energy, the Department of Defense, and other government agencies. The principal goal of this project was to develop an eye-safe, robust, low-cost, lightweight, 3D structured lighting sensor for use in broad daylight outdoor applications. The market for this technology is wide open due to the unavailability of such a sensor. Currently available laser scanners are slow, bulky and heavy, expensive, fragile, short-range, sensitive to vibration (highly problematic for moving platforms), and unreliable for outdoor use in bright sunlight conditions. Eye-safety issues are a primary concern for currently available laser-based sensors. Passive, stereo-imaging sensors are available for 3D sensing but suffer from several limitations : computationally intensive, require a lighted environment (natural or man-made light source), and don't work for many scenes or regions lacking texture or with ambiguous texture. Our approach leveraged from the advanced capabilities of modern CCD camera technology and Center 6600's expertise in 3D world modeling, mapping, and analysis, using structured lighting. We have a diverse customer base for indoor mapping applications and this research extends our current technology's lifecycle and opens a new market base for outdoor 3D mapping. Applications include precision mapping, autonomous navigation, dexterous manipulation, surveillance and

  10. Automated Algorithms for Quantum-Level Accuracy in Atomistic Simulations: LDRD Final Report.

    SciTech Connect

    Thompson, Aidan P.; Schultz, Peter A.; Crozier, Paul; Moore, Stan Gerald; Swiler, Laura Painton; Stephens, John Adam; Trott, Christian Robert; Foiles, Stephen M.; Tucker, Garritt J.

    2014-09-01

    This report summarizes the result of LDRD project 12-0395, titled %22Automated Algorithms for Quantum-level Accuracy in Atomistic Simulations.%22 During the course of this LDRD, we have developed an interatomic potential for solids and liquids called Spectral Neighbor Analysis Poten- tial (SNAP). The SNAP potential has a very general form and uses machine-learning techniques to reproduce the energies, forces, and stress tensors of a large set of small configurations of atoms, which are obtained using high-accuracy quantum electronic structure (QM) calculations. The local environment of each atom is characterized by a set of bispectrum components of the local neighbor density projected on to a basis of hyperspherical harmonics in four dimensions. The SNAP coef- ficients are determined using weighted least-squares linear regression against the full QM training set. This allows the SNAP potential to be fit in a robust, automated manner to large QM data sets using many bispectrum components. The calculation of the bispectrum components and the SNAP potential are implemented in the LAMMPS parallel molecular dynamics code. Global optimization methods in the DAKOTA software package are used to seek out good choices of hyperparameters that define the overall structure of the SNAP potential. FitSnap.py, a Python-based software pack- age interfacing to both LAMMPS and DAKOTA is used to formulate the linear regression problem, solve it, and analyze the accuracy of the resultant SNAP potential. We describe a SNAP potential for tantalum that accurately reproduces a variety of solid and liquid properties. Most significantly, in contrast to existing tantalum potentials, SNAP correctly predicts the Peierls barrier for screw dislocation motion. We also present results from SNAP potentials generated for indium phosphide (InP) and silica (SiO 2 ). We describe efficient algorithms for calculating SNAP forces and energies in molecular dynamics simulations using massively parallel

  11. Final report on LDRD Project: The double electron layer tunneling transistor (DELTT)

    SciTech Connect

    Simmons, J.A.; Moon, J.S.; Blount, M.A.

    1998-06-01

    This report describes the research accomplishments achieved under the LDRD Project ``Double Electron Layer Tunneling Transistor.`` The main goal of this project was to investigate whether the recently discovered phenomenon of 2D-2D tunneling in GaAs/AlGaAs double quantum wells (DQWs), investigated in a previous LDRD, could be harnessed and implemented as the operating principle for a new type of tunneling device the authors proposed, the double electron layer tunneling transistor (DELTT). In parallel with this main thrust of the project, they also continued a modest basic research effort on DQW physics issues, with significant theoretical support. The project was a considerable success, with the main goal of demonstrating a working prototype of the DELTT having been achieved. Additional DELTT advances included demonstrating good electrical characteristics at 77 K, demonstrating both NMOS and CMOS-like bi-stable memories at 77 K using the DELTT, demonstrating digital logic gates at 77 K, and demonstrating voltage-controlled oscillators at 77 K. In order to successfully fabricate the DELTT, the authors had to develop a novel flip-chip processing scheme, the epoxy-bond-and-stop-etch (EBASE) technique. This technique was latter improved so as to be amenable to electron-beam lithography, allowing the fabrication of DELTTs with sub-micron features, which are expected to be extremely high speed. In the basic physics area they also made several advances, including a measurement of the effective mass of electrons in the hour-glass orbit of a DQW subject to in-plane magnetic fields, and both measurements and theoretical calculations of the full Landau level spectra of DQWs in both perpendicular and in-plane magnetic fields. This last result included the unambiguous demonstration of magnetic breakdown of the Fermi surface. Finally, they also investigated the concept of a far-infrared photodetector based on photon assisted tunneling in a DQW. Absorption calculations showed a

  12. One step process for producing dense aluminum nitride and composites thereof

    DOEpatents

    Holt, J. Birch; Kingman, Donald D.; Bianchini, Gregory M.

    1989-01-01

    A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  13. One step process for producing dense aluminum nitride and composites thereof

    DOEpatents

    Holt, J.B.; Kingman, D.D.; Bianchini, G.M.

    1989-10-31

    A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1,000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  14. Inspection of free-form surfaces using dense range data

    NASA Astrophysics Data System (ADS)

    Bispo, Edvaldo M.; Fisher, Robert B.

    1994-11-01

    This paper presents some research on the use of dense range data for the automatic inspection of mechanical parts that have free-form surfaces. Given a part to be inspected and a corresponding model of the part, the first step towards inspecting the part is the acquisition of a range image of it. In order to be able to compare the part image and its stored model, it is necessary to align the model with the range image of the part. This process, called registration, finds the rigid transformation that superposes model and data. After the registration, the actual inspection uses the range image to verify if all the features predicted in the model are presented and within tolerance. Free-form surfaces are particularly interesting in that few inspection processes can inspect surface shape across the whole surface. We focus on the inspection of free-form surfaces and present some results concerning the extraction of nominal shape models from dense range data using B-splines and the use of B-spline models of free-form surfaces for the purposes of registration.

  15. Atomic Transitions in Dense Plasmas

    NASA Astrophysics Data System (ADS)

    Murillo, Michael Sean

    Motivation for the study of hot, dense ( ~solid density) plasmas has historically been in connection with stellar interiors. In recent years, however, there has been a growing interest in such plasmas due to their relevance to short wavelength (EUV and x-ray) lasers, inertial confinement fusion, and optical harmonic generation. In constrast to the stellar plasmas, these laboratory plasmas are typically composed of high-z elements and are not in thermal equilibrium. Descriptions of nonthermal plasma experiments must necessarily involve the consideration of the various atomic processes and the rates at which they occur. Traditionally, the rates of collisional atomic processes are calculated by considering a binary collision picture. For example, a single electron may be taken to collisionally excite an ion. A cross section may be defined for this process and, multiplying by a flux, the rate may be obtained. In a high density plasma this binary picture clearly breaks down as the electrons no longer act independently of each other. The cross section is ill-defined in this regime and another approach is needed to obtain rates. In this thesis an approach based on computing rates without recourse to a cross section is presented. In this approach, binary collisions are replaced by stochastic density fluctuations. It is then these density fluctuations which drive transitions in the ions. Furthermore, the oscillator strengths for the transitions are computed in screened Coulomb potentials which reflect the average polarization of the plasma near the ion. Numerical computations are presented for the collisional ionization rate. The effects of screening in the plasma -ion interaction are investigated for He^+ ions in a plasma near solid density. It is shown that dynamic screening plays an important role in this process. Then, density effects in the oscillator strength are explored for both He^+ and Ar^{+17}. Approximations which introduce a nonorthogonality between the initial

  16. Millimeter- and submillimeter-wave nanoscience : LDRD project 122359 final report.

    SciTech Connect

    Lee, Mark

    2008-09-01

    LDRD Project 122359 was a nine-month, late-start effort that pursued initial experiments studying the fundamental electrodynamic response properties of various nanomaterials from millimeter-wave (above roughly 30 GHz) up to submillimeter-wave (above roughly 0.1 THz) frequencies. The nine months of this project's duration produced two main empirical findings. First, Fourier transform reflectance spectroscopy on SrTiO{sub 3} nanocrystals from 0.2 to 10 THz frequency showed signatures of two optical phonons that correspond to known optical modes in bulk crystal SrTiO{sub 3}. However, quantitative differences between the nanoparticle and bulk spectra suggest that one or both of these phonons may shift frequency and weaken in nanoparticles relative to bulk crystal. Second, heavily doped n-type GaAs nanowires were synthesized for the purpose of creating high frequency diodes to study non-linear frequency conversion properties of compound semiconductor nanowires. It was found that incorporation of a heavy concentration of dopants interferes with the growth of these nanowires. While DC measurements showed reasonable diode-like current-voltage properties, the current state-of-the-art material properties of these nanowires are still unsuitable for millimeter-wave testing and applications.

  17. Final Report for LDRD Project on Rapid Problem Setup for Mesh-Based Simulation (Rapsodi)

    SciTech Connect

    Brown, D L; Henshaw, W; Petersson, N A; Fast, P; Chand, K

    2003-02-07

    Under LLNL Exploratory Research LDRD funding, the Rapsodi project developed rapid setup technology for computational physics and engineering problems that require computational representations of complex geometry. Many simulation projects at LLNL involve the solution of partial differential equations in complex 3-D geometries. A significant bottleneck in carrying out these simulations arises in converting some specification of a geometry, such as a computer-aided design (CAD) drawing to a computationally appropriate 3-D mesh that can be used for simulation and analysis. Even using state-of-the-art mesh generation software, this problem setup step typically has required weeks or months, which is often much longer than required to carry out the computational simulation itself. The Rapsodi project built computational tools and designed algorithms that help to significantly reduce this setup time to less than a day for many realistic problems. The project targeted rapid setup technology for computational physics and engineering problems that use mixed-element unstructured meshes, overset meshes or Cartesian-embedded boundary (EB) meshes to represent complex geometry. It also built tools that aid in constructing computational representations of geometry for problems that do not require a mesh. While completely automatic mesh generation is extremely difficult, the amount of manual labor required can be significantly reduced. By developing novel, automated, component-based mesh construction procedures and automated CAD geometry repair and cleanup tools, Rapsodi has significantly reduced the amount of hand crafting required to generate geometry and meshes for scientific simulation codes.

  18. Biomimetic air sampling for detection of low concentrations of molecules and bioagents : LDRD 52744 final report.

    SciTech Connect

    Hughes, Robert Clark

    2003-12-01

    Present methods of air sampling for low concentrations of chemicals like explosives and bioagents involve noisy and power hungry collectors with mechanical parts for moving large volumes of air. However there are biological systems that are capable of detecting very low concentrations of molecules with no mechanical moving parts. An example is the silkworm moth antenna which is a highly branched structure where each of 100 branches contains about 200 sensory 'hairs' which have dimensions of 2 microns wide by 100 microns long. The hairs contain about 3000 pores which is where the gas phase molecules enter the aqueous (lymph) phase for detection. Simulations of diffusion of molecules indicate that this 'forest' of hairs is 'designed' to maximize the extraction of the vapor phase molecules. Since typical molecules lose about 4 decades in diffusion constant upon entering the liquid phase, it is important to allow air diffusion to bring the molecule as close to the 'sensor' as possible. The moth acts on concentrations as low as 1000 molecules per cubic cm. (one part in 1e16). A 3-D collection system of these dimensions could be fabricated by micromachining techniques available at Sandia. This LDRD addresses the issues involved with extracting molecules from air onto micromachined structures and then delivering those molecules to microsensors for detection.

  19. Fusion of radar data to extract 3-dimensional objects LDRD final report

    SciTech Connect

    Fellerhoff, R.; Hensley, B.; Carande, R.; Burkhart, G.; Ledner, R.

    1997-03-01

    Interferometric Synthetic Aperture Radar (IFSAR) is a very promising technology for remote mapping of 3-Dimensional objects. In particular, 3-D maps of urban areas are extremely important to a wide variety of users, both civilian and military. However, 3-D maps produced by traditional optical stereo (stereogrammetry) techniques can be quite expensive to obtain, and accurate urban maps can only be obtained with a large amount of human-intensive interpretation work. IFSAR has evolved over the last decade as a mapping technology that promises to eliminate much of the human-intensive work in producing elevation maps. However, IFSAR systems have only been robustly demonstrated in non-urban areas, and have not traditionally been able to produce data with enough detail to be of general use in urban areas. Sandia Laboratories Twin Otter IFSAR was the first mapping radar system with the proper parameter set to provide sufficiently detailed information in a large number of urban areas. The goal of this LDRD was to fuse previously unused information derived from IFSAR data in urban areas that can be used to extract accurate digital elevation models (DEMs) over wide areas without intensive human interaction.

  20. LDRD LW Project Final Report:Resolving the Earthquake Source Scaling Problem

    SciTech Connect

    Mayeda, K; Felker, S; Gok, R; O'Boyle, J; Walter, W R; Ruppert, S

    2004-02-10

    The scaling behavior of basic earthquake source parameters such as the energy release per unit area of fault slip, quantitatively measured as the apparent stress, is currently in dispute. There are compelling studies that show apparent stress is constant over a wide range of moments (e.g. Choy and Boatwright, 1995; McGarr, 1999; Ide and Beroza, 2001, Ide et al. 2003). Other equally compelling studies find the apparent stress increases with moment (e.g. Kanamori et al., 1993; Abercrombie, 1995; Mayeda and Walter, 1996; Izutani and Kanamori, 2001; Richardson and Jordan, 2002). The resolution of this issue is complicated by the difficulty of accurately accounting for attenuation, radiation inhomogeneities, bandwidth and determining the seismic energy radiated by earthquakes over a wide range of event sizes in a consistent manner. As one part of our LDRD project we convened a one-day workshop on July 24, 2003 in Livermore to review the current state of knowledge on this topic and discuss possible methods of resolution with many of the world's foremost experts.

  1. Final report on LDRD project : biodiesel production from vegetable oils using slit-channel reactors.

    SciTech Connect

    Kalu, E. Eric; Chen, Ken Shuang

    2008-01-01

    This report documents work done for a late-start LDRD project, which was carried out during the last quarter of FY07. The objective of this project was to experimentally explore the feasibility of converting vegetable (e.g., soybean) oils to biodiesel by employing slit-channel reactors and solid catalysts. We first designed and fabricated several slit-channel reactors with varying channel depths, and employed them to investigate the improved performance of slit-channel reactors over traditional batch reactors using a NaOH liquid catalyst. We then evaluated the effectiveness of several solid catalysts, including CaO, ZnO, MgO, ZrO{sub 2}, calcium gluconate, and heteropolyacid or HPA (Cs{sub 2.5}H{sub 0.5}PW{sub 12}O{sub 40}), for catalyzing the soybean oil-to-biodiesel transesterification reaction. We found that the slit-channel reactor performance improves as channel depth decreases, as expected; and the conversion efficiency of a slit-channel reactor is significantly higher when its channel is very shallow. We further confirmed CaO as having the highest catalytic activity among the solid catalysts tested, and we demonstrated for the first time calcium gluconate as a promising solid catalyst for converting soybean oil to biodiesel, based on our preliminary batch-mode conversion experiments.

  2. Real-time discriminatory sensors for water contamination events :LDRD 52595 final report.

    SciTech Connect

    Borek, Theodore Thaddeus III; Carrejo-Simpkins, Kimberly; Wheeler, David Roger; Adkins, Douglas Ray; Robinson, Alex Lockwood; Irwin, Adriane Nadine; Lewis, Patrick Raymond; Goodin, Andrew M.; Shelmidine, Gregory J.; Dirk, Shawn M.; Chambers, William Clayton; Mowry, Curtis Dale; Showalter, Steven Kedrick

    2005-10-01

    The gas-phase {mu}ChemLab{trademark} developed by Sandia can detect volatile organics and semi-volatiles organics via gas phase sampling . The goal of this three year Laboratory Directed Research and Development (LDRD) project was to adapt the components and concepts used by the {mu}ChemLab{trademark} system towards the analysis of water-borne chemicals of current concern. In essence, interfacing the gas-phase {mu}ChemLab{trademark} with water to bring the significant prior investment of Sandia and the advantages of microfabrication and portable analysis to a whole new world of important analytes. These include both chemical weapons agents and their hydrolysis products and disinfection by-products such as Trihalomethanes (THMs) and haloacetic acids (HAAs). THMs and HAAs are currently regulated by EPA due to health issues, yet water utilities do not have rapid on-site methods of detection that would allow them to adjust their processes quickly; protecting consumers, meeting water quality standards, and obeying regulations more easily and with greater confidence. This report documents the results, unique hardware and devices, and methods designed during the project toward the goal stated above. It also presents and discusses the portable field system to measure THMs developed in the course of this project.

  3. LDRD final report: Automated planning and programming of assembly of fully 3D mechanisms

    SciTech Connect

    Kaufman, S.G.; Wilson, R.H.; Jones, R.E.; Calton, T.L.; Ames, A.L.

    1996-11-01

    This report describes the results of assembly planning research under the LDRD. The assembly planning problem is that of finding a sequence of assembly operations, starting from individual parts, that will result in complete assembly of a device specified as a CAD model. The automated assembly programming problem is that of automatically producing a robot program that will carry out a given assembly sequence. Given solutions to both of these problems, it is possible to automatically program a robot to assemble a mechanical device given as a CAD data file. This report describes the current state of our solutions to both of these problems, and a software system called Archimedes 2 we have constructed to automate these solutions. Because Archimedes 2 can input CAD data in several standard formats, we have been able to test it on a number of industrial assembly models more complex than any before attempted by automated assembly planning systems, some having over 100 parts. A complete path from a CAD model to an automatically generated robot program for assembling the device represented by the CAD model has also been demonstrated.

  4. Analysis of electromagnetic scattering by nearly periodic structures: an LDRD report.

    SciTech Connect

    Johnson, William Arthur; Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Wilton, Donald R. (University of Houston, Houston, TX); Basilio, Lorena I.; Peters, David William; Capolino, F.

    2006-10-01

    In this LDRD we examine techniques to analyze the electromagnetic scattering from structures that are nearly periodic. Nearly periodic could mean that one of the structure's unit cells is different from all the others--a defect. It could also mean that the structure is truncated, or butted up against another periodic structure to form a seam. Straightforward electromagnetic analysis of these nearly periodic structures requires us to grid the entire structure, which would overwhelm today's computers and the computers in the foreseeable future. In this report we will examine various approximations that allow us to continue to exploit some aspects of the structure's periodicity and thereby reduce the number of unknowns required for analysis. We will use the Green's Function Interpolation with a Fast Fourier Transform (GIFFT) to examine isolated defects both in the form of a source dipole over a meta-material slab and as a rotated dipole in a finite array of dipoles. We will look at the numerically exact solution of a one-dimensional seam. In order to solve a two-dimensional seam, we formulate an efficient way to calculate the Green's function of a 1d array of point sources. We next formulate ways of calculating the far-field due to a seam and due to array truncation based on both array theory and high-frequency asymptotic methods. We compare the high-frequency and GIFFT results. Finally, we use GIFFT to solve a simple, two-dimensional seam problem.

  5. Network discovery, characterization, and prediction : a grand challenge LDRD final report.

    SciTech Connect

    Kegelmeyer, W. Philip, Jr.

    2010-11-01

    This report is the final summation of Sandia's Grand Challenge LDRD project No.119351, 'Network Discovery, Characterization and Prediction' (the 'NGC') which ran from FY08 to FY10. The aim of the NGC, in a nutshell, was to research, develop, and evaluate relevant analysis capabilities that address adversarial networks. Unlike some Grand Challenge efforts, that ambition created cultural subgoals, as well as technical and programmatic ones, as the insistence on 'relevancy' required that the Sandia informatics research communities and the analyst user communities come to appreciate each others needs and capabilities in a very deep and concrete way. The NGC generated a number of technical, programmatic, and cultural advances, detailed in this report. There were new algorithmic insights and research that resulted in fifty-three refereed publications and presentations; this report concludes with an abstract-annotated bibliography pointing to them all. The NGC generated three substantial prototypes that not only achieved their intended goals of testing our algorithmic integration, but which also served as vehicles for customer education and program development. The NGC, as intended, has catalyzed future work in this domain; by the end it had already brought in, in new funding, as much funding as had been invested in it. Finally, the NGC knit together previously disparate research staff and user expertise in a fashion that not only addressed our immediate research goals, but which promises to have created an enduring cultural legacy of mutual understanding, in service of Sandia's national security responsibilities in cybersecurity and counter proliferation.

  6. Robust Planning for Autonomous Navigation of Mobile Robots in Unstructured, Dynamic Environments: An LDRD Final Report

    SciTech Connect

    EISLER, G. RICHARD

    2002-08-01

    This report summarizes the analytical and experimental efforts for the Laboratory Directed Research and Development (LDRD) project entitled ''Robust Planning for Autonomous Navigation of Mobile Robots In Unstructured, Dynamic Environments (AutoNav)''. The project goal was to develop an algorithmic-driven, multi-spectral approach to point-to-point navigation characterized by: segmented on-board trajectory planning, self-contained operation without human support for mission duration, and the development of appropriate sensors and algorithms to navigate unattended. The project was partially successful in achieving gains in sensing, path planning, navigation, and guidance. One of three experimental platforms, the Minimalist Autonomous Testbed, used a repetitive sense-and-re-plan combination to demonstrate the majority of elements necessary for autonomous navigation. However, a critical goal for overall success in arbitrary terrain, that of developing a sensor that is able to distinguish true obstacles that need to be avoided as a function of vehicle scale, still needs substantial research to bring to fruition.

  7. A configuration space toolkit for automated spatial reasoning: Technical results and LDRD project final report

    SciTech Connect

    Xavier, P.G.; LaFarge, R.A.

    1997-02-01

    A robot`s configuration space (c-space) is the space of its kinematic degrees of freedom, e.g., the joint-space of an arm. Sets in c-space can be defined that characterize a variety of spatial relationships, such as contact between the robot and its environment. C-space techniques have been fundamental to research progress in areas such as motion planning and physically-based reasoning. However, practical progress has been slowed by the difficulty of implementing the c-space abstraction inside each application. For this reason, we proposed a Configuration Space Toolkit of high-performance algorithms and data structures meeting these needs. Our intent was to develop this robotics software to provide enabling technology to emerging applications that apply the c-space abstraction, such as advanced motion planning, teleoperation supervision, mechanism functional analysis, and design tools. This final report presents the research results and technical achievements of this LDRD project. Key results and achievements included (1) a hybrid Common LISP/C prototype that implements the basic C-Space abstraction, (2) a new, generic, algorithm for constructing hierarchical geometric representations, and (3) a C++ implementation of an algorithm for fast distance computation, interference detection, and c-space point-classification. Since the project conclusion, motion planning researchers in Sandia`s Intelligent Systems and Robotics Center have been using the CSTk libcstk.so C++ library. The code continues to be used, supported, and improved by projects in the ISRC.

  8. ParaText : scalable solutions for processing and searching very large document collections : final LDRD report.

    SciTech Connect

    Crossno, Patricia Joyce; Dunlavy, Daniel M.; Stanton, Eric T.; Shead, Timothy M.

    2010-09-01

    This report is a summary of the accomplishments of the 'Scalable Solutions for Processing and Searching Very Large Document Collections' LDRD, which ran from FY08 through FY10. Our goal was to investigate scalable text analysis; specifically, methods for information retrieval and visualization that could scale to extremely large document collections. Towards that end, we designed, implemented, and demonstrated a scalable framework for text analysis - ParaText - as a major project deliverable. Further, we demonstrated the benefits of using visual analysis in text analysis algorithm development, improved performance of heterogeneous ensemble models in data classification problems, and the advantages of information theoretic methods in user analysis and interpretation in cross language information retrieval. The project involved 5 members of the technical staff and 3 summer interns (including one who worked two summers). It resulted in a total of 14 publications, 3 new software libraries (2 open source and 1 internal to Sandia), several new end-user software applications, and over 20 presentations. Several follow-on projects have already begun or will start in FY11, with additional projects currently in proposal.

  9. Soot formation, transport, and radiation in unsteady diffusion flames : LDRD final report.

    SciTech Connect

    Suo-Anttila, Jill Marie; Williams, Timothy C.; Shaddix, Christopher R.; Jensen, Kirk A.; Blevins, Linda Gail; Kearney, Sean Patrick; Schefer, Robert W.

    2004-10-01

    Fires pose the dominant risk to the safety and security of nuclear weapons, nuclear transport containers, and DOE and DoD facilities. The thermal hazard from these fires primarily results from radiant emission from high-temperature flame soot. Therefore, it is necessary to understand the local transport and chemical phenomena that determine the distributions of soot concentration, optical properties, and temperature in order to develop and validate constitutive models for large-scale, high-fidelity fire simulations. This report summarizes the findings of a Laboratory Directed Research and Development (LDRD) project devoted to obtaining the critical experimental information needed to develop such constitutive models. A combination of laser diagnostics and extractive measurement techniques have been employed in both steady and pulsed laminar diffusion flames of methane, ethylene, and JP-8 surrogate burning in air. For methane and ethylene, both slot and coannular flame geometries were investigated, as well as normal and inverse diffusion flame geometries. For the JP-8 surrogate, coannular normal diffusion flames were investigated. Soot concentrations, polycyclic aromatic hydrocarbon (PAH) laser-induced fluorescence (LIF) signals, hydroxyl radical (OH) LIF, acetylene and water vapor concentrations, soot zone temperatures, and the velocity field were all successfully measured in both steady and unsteady versions of these various flames. In addition, measurements were made of the soot microstructure, soot dimensionless extinction coefficient (&), and the local radiant heat flux. Taken together, these measurements comprise a unique, extensive database for future development and validation of models of soot formation, transport, and radiation.

  10. High accuracy integrated global positioning system/inertial navigation system LDRD: Final report

    SciTech Connect

    Owen, T.E.; Meindl, M.A.; Fellerhoff, J.R.

    1997-03-01

    This report contains the results of a Sandia National Laboratories Directed Research and Development (LDRD) program to investigate the integration of Global Positioning System (GPS) and inertial navigation system (INS) technologies toward the goal of optimizing the navigational accuracy of the combined GPSANS system. The approach undertaken is to integrate the data from an INS, which has long term drifts, but excellent short term accuracy, with GPS carrier phase signal information, which is accurate to the sub-centimeter level, but requires continuous tracking of the GPS signals. The goal is to maintain a sub-meter accurate navigation solution while the vehicle is in motion by using the GPS measurements to estimate the INS navigation errors and then using the refined INS data to aid the GPS carrier phase cycle slip detection and correction and bridge dropouts in the GPS data. The work was expanded to look at GPS-based attitude determination, using multiple GPS receivers and antennas on a single platform, as a possible navigation aid. Efforts included not only the development of data processing algorithms and software, but also the collection and analysis of GPS and INS flight data aboard a Twin Otter aircraft. Finally, the application of improved navigation system accuracy to synthetic aperture radar (SAR) target location is examined.

  11. LDRD project final report : hybrid AI/cognitive tactical behavior framework for LVC.

    SciTech Connect

    Djordjevich, Donna D.; Xavier, Patrick Gordon; Brannon, Nathan Gregory; Hart, Brian E.; Hart, Derek H.; Little, Charles Quentin; Oppel, Fred John III; Linebarger, John Michael; Parker, Eric Paul

    2012-01-01

    This Lab-Directed Research and Development (LDRD) sought to develop technology that enhances scenario construction speed, entity behavior robustness, and scalability in Live-Virtual-Constructive (LVC) simulation. We investigated issues in both simulation architecture and behavior modeling. We developed path-planning technology that improves the ability to express intent in the planning task while still permitting an efficient search algorithm. An LVC simulation demonstrated how this enables 'one-click' layout of squad tactical paths, as well as dynamic re-planning for simulated squads and for real and simulated mobile robots. We identified human response latencies that can be exploited in parallel/distributed architectures. We did an experimental study to determine where parallelization would be productive in Umbra-based force-on-force (FOF) simulations. We developed and implemented a data-driven simulation composition approach that solves entity class hierarchy issues and supports assurance of simulation fairness. Finally, we proposed a flexible framework to enable integration of multiple behavior modeling components that model working memory phenomena with different degrees of sophistication.

  12. RF/microwave properties of nanotubes and nanowires : LDRD Project 105876 final report.

    SciTech Connect

    Scrymgeour, David; Lee, Mark; Hsu, Julia W. P.; Highstrete, Clark

    2009-09-01

    LDRD Project 105876 was a research project whose primary goal was to discover the currently unknown science underlying the basic linear and nonlinear electrodynamic response of nanotubes and nanowires in a manner that will support future efforts aimed at converting forefront nanoscience into innovative new high-frequency nanodevices. The project involved experimental and theoretical efforts to discover and understand high frequency (MHz through tens of GHz) electrodynamic response properties of nanomaterials, emphasizing nanowires of silicon, zinc oxide, and carbon nanotubes. While there is much research on DC electrical properties of nanowires, electrodynamic characteristics still represent a major new frontier in nanotechnology. We generated world-leading insight into how the low dimensionality of these nanomaterials yields sometimes desirable and sometimes problematic high-frequency properties that are outside standard model electron dynamics. In the cases of silicon nanowires and carbon nanotubes, evidence of strong disorder or glass-like charge dynamics was measured, indicating that these materials still suffer from serious inhomogeneities that limit there high frequency performance. Zinc oxide nanowires were found to obey conventional Drude dynamics. In all cases, a significant practical problem involving large impedance mismatch between the high intrinsic impedance of all nanowires and nanotubes and high-frequency test equipment had to be overcome.

  13. Final report for LDRD project 11-0783 : directed robots for increased military manpower effectiveness.

    SciTech Connect

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Wagner, John S.; Xavier, Patrick Gordon; Morrow, James Dan

    2011-09-01

    The purpose of this LDRD is to develop technology allowing warfighters to provide high-level commands to their unmanned assets, freeing them to command a group of them or commit the bulk of their attention elsewhere. To this end, a brain-emulating cognition and control architecture (BECCA) was developed, incorporating novel and uniquely capable feature creation and reinforcement learning algorithms. BECCA was demonstrated on both a mobile manipulator platform and on a seven degree of freedom serial link robot arm. Existing military ground robots are almost universally teleoperated and occupy the complete attention of an operator. They may remove a soldier from harm's way, but they do not necessarily reduce manpower requirements. Current research efforts to solve the problem of autonomous operation in an unstructured, dynamic environment fall short of the desired performance. In order to increase the effectiveness of unmanned vehicle (UV) operators, we proposed to develop robots that can be 'directed' rather than remote-controlled. They are instructed and trained by human operators, rather than driven. The technical approach is modeled closely on psychological and neuroscientific models of human learning. Two Sandia-developed models are utilized in this effort: the Sandia Cognitive Framework (SCF), a cognitive psychology-based model of human processes, and BECCA, a psychophysical-based model of learning, motor control, and conceptualization. Together, these models span the functional space from perceptuo-motor abilities, to high-level motivational and attentional processes.

  14. Neutrino Propagation in Dense Magnetized Matter

    NASA Astrophysics Data System (ADS)

    Arbuzova, E. V.; Lobanov, A. E.; Murchikova, E. M.

    2009-01-01

    We obtained a complete system of solutions of the Dirac-Pauli equation for a massive neutrino interacting with dense matter and strong electromagnetic field. We demonstrated that these solutions can describe precession of the neutrino spin.

  15. Wide Variation Seen in 'Dense' Breast Diagnoses

    MedlinePlus

    ... defined mammography patients' breasts as dense. Higher breast density is a risk factor for breast cancer, experts ... could have implications for the so-called breast density notification laws that have been passed in about ...

  16. Magnetic Phases in Dense Quark Matter

    SciTech Connect

    Incera, Vivian de la

    2007-10-26

    In this paper I discuss the magnetic phases of the three-flavor color superconductor. These phases can take place at different field strengths in a highly dense quark system. Given that the best natural candidates for the realization of color superconductivity are the extremely dense cores of neutron stars, which typically have very large magnetic fields, the magnetic phases here discussed could have implications for the physics of these compact objects.

  17. Dense loading of catalyst improves hydrotreater performance

    SciTech Connect

    Nooy, F.M.

    1984-11-12

    This paper discusses the advantages of increased capacity and improved catalyst/oil contact in existing hydrotreating units. The similarities between catalyst loading and other material processes are reviewed. Catalyst bed activity is examined. Dense loading systems are reviewed in detail. Over the last years, many refiners have gained experience with the benefits of dense loading techniques, and these techniques are gaining more and more acceptance.

  18. Dynamical theory of dense groups of galaxies

    NASA Technical Reports Server (NTRS)

    Mamon, Gary A.

    1990-01-01

    It is well known that galaxies associate in groups and clusters. Perhaps 40% of all galaxies are found in groups of 4 to 20 galaxies (e.g., Tully 1987). Although most groups appear to be so loose that the galaxy interactions within them ought to be insignificant, the apparently densest groups, known as compact groups appear so dense when seen in projection onto the plane of the sky that their members often overlap. These groups thus appear as dense as the cores of rich clusters. The most popular catalog of compact groups, compiled by Hickson (1982), includes isolation among its selection critera. Therefore, in comparison with the cores of rich clusters, Hickson's compact groups (HCGs) appear to be the densest isolated regions in the Universe (in galaxies per unit volume), and thus provide in principle a clean laboratory for studying the competition of very strong gravitational interactions. The $64,000 question here is then: Are compact groups really bound systems as dense as they appear? If dense groups indeed exist, then one expects that each of the dynamical processes leading to the interaction of their member galaxies should be greatly enhanced. This leads us to the questions: How stable are dense groups? How do they form? And the related question, fascinating to any theorist: What dynamical processes predominate in dense groups of galaxies? If HCGs are not bound dense systems, but instead 1D change alignments (Mamon 1986, 1987; Walke & Mamon 1989) or 3D transient cores (Rose 1979) within larger looser systems of galaxies, then the relevant question is: How frequent are chance configurations within loose groups? Here, the author answers these last four questions after comparing in some detail the methods used and the results obtained in the different studies of dense groups.

  19. Dissociation energy of molecules in dense gases

    NASA Technical Reports Server (NTRS)

    Kunc, J. A.

    1992-01-01

    A general approach is presented for calculating the reduction of the dissociation energy of diatomic molecules immersed in a dense (n = less than 10 exp 22/cu cm) gas of molecules and atoms. The dissociation energy of a molecule in a dense gas differs from that of the molecule in vacuum because the intermolecular forces change the intramolecular dynamics of the molecule, and, consequently, the energy of the molecular bond.

  20. Fabric variables in dense sheared suspensions

    NASA Astrophysics Data System (ADS)

    Radjai, Farhang; Amarsid, Lhassan; Delenne, Jean-Yves

    The rheology of granular flows and dense suspensions can be described in terms of their effective shear and bulk viscosities as a function of packing fraction. Using stress partition and equivalence between frictional and viscous descriptions in the dense state, we show that the effective viscosities can be expressed in terms of the force-network anisotropy. This is supported by our extensive DEM-LBM simulations for a broad range of inertial and viscous parameters.

  1. Molecular dynamics for dense matter

    NASA Astrophysics Data System (ADS)

    Maruyama, Toshiki; Watanabe, Gentaro; Chiba, Satoshi

    2012-08-01

    We review a molecular dynamics method for nucleon many-body systems called quantum molecular dynamics (QMD), and our studies using this method. These studies address the structure and the dynamics of nuclear matter relevant to neutron star crusts, supernova cores, and heavy-ion collisions. A key advantage of QMD is that we can study dynamical processes of nucleon many-body systems without any assumptions about the nuclear structure. First, we focus on the inhomogeneous structures of low-density nuclear matter consisting not only of spherical nuclei but also of nuclear "pasta", i.e., rod-like and slab-like nuclei. We show that pasta phases can appear in the ground and equilibrium states of nuclear matter without assuming nuclear shape. Next, we show our simulation of compression of nuclear matter which corresponds to the collapsing stage of supernovae. With the increase in density, a crystalline solid of spherical nuclei changes to a triangular lattice of rods by connecting neighboring nuclei. Finally, we discuss fragment formation in expanding nuclear matter. Our results suggest that a generally accepted scenario based on the liquid-gas phase transition is not plausible at lower temperatures.

  2. METHOD OF PRODUCING DENSE CONSOLIDATED METALLIC REGULUS

    DOEpatents

    Magel, T.T.

    1959-08-11

    A methcd is presented for reducing dense metal compositions while simultaneously separating impurities from the reduced dense metal and casting the reduced parified dense metal, such as uranium, into well consolidated metal ingots. The reduction is accomplished by heating the dense metallic salt in the presence of a reducing agent, such as an alkali metal or alkaline earth metal in a bomb type reacting chamber, while applying centrifugal force on the reacting materials. Separation of the metal from the impurities is accomplished essentially by the incorporation of a constricted passageway at the vertex of a conical reacting chamber which is in direct communication with a collecting chamber. When a centrifugal force is applled to the molten metal and slag from the reduction in a direction collinear with the axis of the constricted passage, the dense molten metal is forced therethrough while the less dense slag is retained within the reaction chamber, resulting in a simultaneous separation of the reduced molten metal from the slag and a compacting of the reduced metal in a homogeneous mass.

  3. LDRD Report FY 03: Structure and Function of Regulatory DNA: A Next Major Challenge in Genomics

    SciTech Connect

    Stubbs, L

    2003-02-18

    With the human genome sequence now available and high quality draft sequences of mouse, rat and many other creatures recently or soon to be released, the field of Genomics has entered an especially exciting phase. The raw materials for locating the {approx}30-40,000 human genes and understanding their basic structure are now online; next, the research community must begin to unravel the mechanisms through which those genes create the complexity of life. Laboratories around the world are already beginning to focus on cataloguing the times, sites and conditions under which each gene is active; others are racing to predict, and then experimentally analyze, the structures of proteins that human genes encode. These activities are extremely important, but they will not reveal the mechanisms through which the correct proteins are activated precisely in the specific cells and at the particular time that is required for normal developmental, health, and in response to the environment. Although we understand well the three-letter code through which genes dictate the production of proteins, the codes through which genes are turned on and off in precise, cell-specific patterns remain a mystery. Unraveling these codes are essential to understanding the functions of genes and the role of human genetic diversity in disease and environmental susceptibility. This problem also represents one of the most exciting challenges in modern biology, drawing in scientists from every discipline to develop the needed biological datasets, measurement technologies and algorithms. The LDRD effort that is the subject of this report was focused on establishing the basic technical and scientific foundations of a well-rounded program in gene regulatory biology at LLNL. The motivation for building these foundations was based on several drivers. First, with the sea-change in genomics, we sought to develop a new, exciting and foreward-thinking research focus for the LLNL genomics team, which could

  4. Integrated superhard and metallic coatings for MEMS : LDRD 57300 final report.

    SciTech Connect

    de Boer, Maarten Pieter; Maboudian, Roya

    2004-12-01

    Two major research areas pertinent to microelectromechanical systems (MEMS) materials and material surfaces were explored and developed in this 5-year PECASE LDRD project carried out by Professor Roya Maboudian and her collaborators at the University of California at Berkeley. In the first research area, polycrystalline silicon carbide (poly-SiC) was developed as a structural material for MEMS. This material is potentially interesting for MEMS because compared to polycrystalline silicon (polysilicon), the structural material in Sandia National Laboratories' SUMMiTV process, it may exhibit high wear resistance, high temperature operation and a high Young's modulus to density ratio. Each of these characteristics may extend the usefulness of MEMS in Sandia National Laboratories' applications. For example, using polycrystalline silicon, wear is an important issue in microengines, temperature degradation is of concern in thermal actuators and the characteristics of resonators can be extended with the same lithography technology. Two methods of depositing poly-SiC from a 1,3-disilabutane source at 650 C to 800 C by low-pressure chemical vapor deposition (LPCVD) were demonstrated. These include a blanket method in which the material is made entirely out of poly-SiC and a method to coat previously released and fabricated polysilicon MEMS. This deposition method is much simpler to use than previous methods such as high temperature LPCVD and atmospheric CVD. Other major processing issues that were surmounted in this LDRD with the poly-SiC film include etching, doping, and residual strain control. SiC is inert and as such is notoriously difficult to etch. Here, an HBr-based chemistry was demonstrated for the first time to make highly selective etching of SiC at high etch rates. Nitrogen was incorporated from an NH3 gas source, resulting in high conductivity films. Residual strain and strain gradient were shown to depend on deposition parameters, and can be made negative or

  5. Final report for LDRD project {open_quotes}A new approach to protein function and structure prediction{close_quotes}

    SciTech Connect

    Phillips, C.A.

    1997-03-01

    This report describes the research performed under the laboratory-Directed Research and Development (LDRD) grant {open_quotes}A new approach to protein function and structure prediction{close_quotes}, funded FY94-6. We describe the goals of the research, motivate and list our improvements to the state of the art in multiple sequence alignment and phylogeny (evolutionary tree) construction, but leave technical details to the six publications resulting from this work. At least three algorithms for phylogeny construction or tree consensus have been implemented and used by researchers outside of Sandia.

  6. RF/Microwave properties and applications of directly assembled nanotubes and nanowires: LDRD project 102662 final report.

    SciTech Connect

    Mayer, Theresa (The Pennyslvania State University, University Park, PA 16802); Vallett, Aaron (The Pennyslvania State University, University Park, PA 16802); Lee, Mark; Shaner, Eric Arthur; Jones, Frank E.; Talin, Albert Alec; Highstrete, Clark

    2006-11-01

    LDRD Project 102662 provided support to pursue experiments aimed at measuring the basic electrodynamic response and possible applications of carbon nanotubes and silicon nanowires at radiofrequency to microwave frequencies, approximately 0.01 to 50 GHz. Under this project, a method was developed to integrate these nanomaterials onto high-frequency compatible co-planar waveguides. The complex reflection and transmission coefficients of the nanomaterials was studied as a function of frequency. From these data, the high-frequency loss characteristics of the nanomaterials were deduced. These data are useful to predict frequency dependence and power dissipation characteristics in new rf/microwave devices incorporating new nanomaterials.

  7. Final Report for LDRD Project 02-FS-009 Gigapixel Surveillance Camera

    SciTech Connect

    Marrs, R E; Bennett, C L

    2010-04-20

    The threats of terrorism and proliferation of weapons of mass destruction add urgency to the development of new techniques for surveillance and intelligence collection. For example, the United States faces a serious and growing threat from adversaries who locate key facilities underground, hide them within other facilities, or otherwise conceal their location and function. Reconnaissance photographs are one of the most important tools for uncovering the capabilities of adversaries. However, current imaging technology provides only infrequent static images of a large area, or occasional video of a small area. We are attempting to add a new dimension to reconnaissance by introducing a capability for large area video surveillance. This capability would enable tracking of all vehicle movements within a very large area. The goal of our project is the development of a gigapixel video surveillance camera for high altitude aircraft or balloon platforms. From very high altitude platforms (20-40 km altitude) it would be possible to track every moving vehicle within an area of roughly 100 km x 100 km, about the size of the San Francisco Bay region, with a gigapixel camera. Reliable tracking of vehicles requires a ground sampling distance (GSD) of 0.5 to 1 m and a framing rate of approximately two frames per second (fps). For a 100 km x 100 km area the corresponding pixel count is 10 gigapixels for a 1-m GSD and 40 gigapixels for a 0.5-m GSD. This is an order of magnitude beyond the 1 gigapixel camera envisioned in our LDRD proposal. We have determined that an instrument of this capacity is feasible.

  8. III-antimonide/nitride based semiconductors for optoelectronic materials and device studies : LDRD 26518 final report.

    SciTech Connect

    Kurtz, Steven Ross; Hargett, Terry W.; Serkland, Darwin Keith; Waldrip, Karen Elizabeth; Modine, Normand Arthur; Klem, John Frederick; Jones, Eric Daniel; Cich, Michael Joseph; Allerman, Andrew Alan; Peake, Gregory Merwin

    2003-12-01

    The goal of this LDRD was to investigate III-antimonide/nitride based materials for unique semiconductor properties and applications. Previous to this study, lack of basic information concerning these alloys restricted their use in semiconductor devices. Long wavelength emission on GaAs substrates is of critical importance to telecommunication applications for cost reduction and integration into microsystems. Currently InGaAsN, on a GaAs substrate, is being commercially pursued for the important 1.3 micrometer dispersion minima of silica-glass optical fiber; due, in large part, to previous research at Sandia National Laboratories. However, InGaAsN has not shown great promise for 1.55 micrometer emission which is the low-loss window of single mode optical fiber used in transatlantic fiber. Other important applications for the antimonide/nitride based materials include the base junction of an HBT to reduce the operating voltage which is important for wireless communication links, and for improving the efficiency of a multijunction solar cell. We have undertaken the first comprehensive theoretical, experimental and device study of this material with promising results. Theoretical modeling has identified GaAsSbN to be a similar or potentially superior candidate to InGaAsN for long wavelength emission on GaAs. We have confirmed these predictions by producing emission out to 1.66 micrometers and have achieved edge emitting and VCSEL electroluminescence at 1.3 micrometers. We have also done the first study of the transport properties of this material including mobility, electron/hole mass, and exciton reduced mass. This study has increased the understanding of the III-antimonide/nitride materials enough to warrant consideration for all of the target device applications.

  9. Chemiresistor microsensors for in-situ monitoring of volatile organic compounds : final LDRD report.

    SciTech Connect

    Thomas, Michael Loren; Hughes, Robert Clark; Kooser, Ara S.; McGrath, Lucas K.; Ho, Clifford Kuofei; Wright, Jerome L.; Davis, Chad Edward

    2003-09-01

    This report provides a summary of the three-year LDRD (Laboratory Directed Research and Development) project aimed at developing microchemical sensors for continuous, in-situ monitoring of volatile organic compounds. A chemiresistor sensor array was integrated with a unique, waterproof housing that allows the sensors to be operated in a variety of media including air, soil, and water. Numerous tests were performed to evaluate and improve the sensitivity, stability, and discriminatory capabilities of the chemiresistors. Field tests were conducted in California, Nevada, and New Mexico to further test and develop the sensors in actual environments within integrated monitoring systems. The field tests addressed issues regarding data acquisition, telemetry, power requirements, data processing, and other engineering requirements. Significant advances were made in the areas of polymer optimization, packaging, data analysis, discrimination, design, and information dissemination (e.g., real-time web posting of data; see www.sandia.gov/sensor). This project has stimulated significant interest among commercial and academic institutions. A CRADA (Cooperative Research and Development Agreement) was initiated in FY03 to investigate manufacturing methods, and a Work for Others contract was established between Sandia and Edwards Air Force Base for FY02-FY04. Funding was also obtained from DOE as part of their Advanced Monitoring Systems Initiative program from FY01 to FY03, and a DOE EMSP contract was awarded jointly to Sandia and INEEL for FY04-FY06. Contracts were also established for collaborative research with Brigham Young University to further evaluate, understand, and improve the performance of the chemiresistor sensors.

  10. Low-Altitude Airbursts and the Impact Threat - Final LDRD Report.

    SciTech Connect

    Boslough, Mark B.; Crawford, David A.

    2007-12-01

    The purpose of this nine-week project was to advance the understanding of low-altitude airbursts by developing the means to model them at extremely high resolution in order to span the scales of entry physics as well as blast wave and plume formation. Small asteroid impacts on Earth are a recognized hazard, but the full nature of the threat is still not well understood. We used shock physics codes to discover emergent phenomena associated with low-altitude airbursts such as the Siberian Tunguska event of 1908 and the Egyptian glass-forming event 29 million years ago. The planetary defense community is beginning to recognize the significant threat from such airbursts. Low-altitude airbursts are the only class of impacts that have a significant probability of occurring within a planning time horizon. There is roughly a 10% chance of a megaton-scale low-altitude airburst event in the next decade.The first part of this LDRD final project report is a preprint of our proceedings paper associated with the plenary presentation at the Hypervelocity Impact Society 2007 Symposium in Williamsburg, Virginia (International Journal of Impact Engineering, in press). The paper summarizes discoveries associated with a series of 2D axially-symmetric CTH simulations. The second part of the report contains slides from an invited presentation at the American Geophysical Union Fall 2007 meeting in San Francisco. The presentation summarizes the results of a series of 3D oblique impact simulations of the 1908 Tunguska explosion. Because of the brevity of this late-start project, the 3D results have not yet been written up for a peer-reviewed publication. We anticipate the opportunity to eventually run simulations that include the actual topography at Tunguska, at which time these results will be published.3

  11. Equilibrium Shaping

    NASA Astrophysics Data System (ADS)

    Izzo, Dario; Petazzi, Lorenzo

    2006-08-01

    We present a satellite path planning technique able to make identical spacecraft aquire a given configuration. The technique exploits a behaviour-based approach to achieve an autonomous and distributed control over the relative geometry making use of limited sensorial information. A desired velocity is defined for each satellite as a sum of different contributions coming from generic high level behaviours: forcing the final desired configuration the behaviours are further defined by an inverse dynamic calculation dubbed Equilibrium Shaping. We show how considering only three different kind of behaviours it is possible to acquire a number of interesting formations and we set down the theoretical framework to find the entire set. We find that allowing a limited amount of communication the technique may be used also to form complex lattice structures. Several control feedbacks able to track the desired velocities are introduced and discussed. Our results suggest that sliding mode control is particularly appropriate in connection with the developed technique.

  12. Massive Star Formation: Characterising Infall and Outflow in dense cores.

    NASA Astrophysics Data System (ADS)

    Akhter, Shaila; Cunningham, Maria; Harvey-Smith, Lisa; Jones, Paul Andrew; Purcell, Cormac; Walsh, Andrew John

    2015-08-01

    Massive stars are some of the most important objects in the Universe, shaping the evolution of galaxies, creating chemical elements, and hence shaping the evolution of the Universe. However, the processes by which they form, and how they shape their environment during their birth processes, are not well understood. We are using NH3 data from the "The H2O Southern Galactic Plane Survey" (HOPS) to define the positions of dense cores/clumps of gas in the southern Galactic plane that are likely to form stars. Due to its effective critical density, NH3 can detect massive star forming regions effectively compared to other tracers. We did a comparative study with different methods for finding clumps and found Fellwalker as the best. We found ~ 10% of the star forming clumps with multiple components and ~ 90% clumps with single component along the line of sight. Then, using data from the "The Millimetre Astronomy Legacy Team 90 GHz" (MALT90) survey, we search for the presence of infall and outflow associated with these cores. We will subsequently use the "3D Molecular Line Radiative Transfer Code" (MOLLIE) to constrain properties of the infall and outflow, such as velocity and mass flow. The aim of the project is to determine how common infall and outflow are in star forming cores, hence providing valuable constraints on the timescales and physical process involved in massive star formation.

  13. Coherent ultra dense wavelength division multiplexing passive optical networks

    NASA Astrophysics Data System (ADS)

    Shahpari, Ali; Ferreira, Ricardo; Ribeiro, Vitor; Sousa, Artur; Ziaie, Somayeh; Tavares, Ana; Vujicic, Zoran; Guiomar, Fernando P.; Reis, Jacklyn D.; Pinto, Armando N.; Teixeira, António

    2015-12-01

    In this paper, we firstly review the progress in ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON), by making use of the key attributes of this technology in the context of optical access and metro networks. Besides the inherit properties of coherent technology, we explore different modulation formats and pulse shaping. The performance is experimentally demonstrated through a 12 × 10 Gb/s bidirectional UDWDM-PON over hybrid 80 km standard single mode fiber (SSMF) and optical wireless link. High density, 6.25 GHz grid, Nyquist shaped 16-ary quadrature amplitude modulation (16QAM) and digital frequency shifting are some of the properties exploited together in the tests. Also, bidirectional transmission in fiber, relevant in the context, is analyzed in terms of nonlinear and back-reflection effects on receiver sensitivity. In addition, as a basis for the discussion on market readiness, we experimentally demonstrate real-time detection of a Nyquist-shaped quaternary phase-shift keying (QPSK) signal using simple 8-bit digital signal processing (DSP) on a field-programmable gate array (FPGA).

  14. Development of dense ceramic membranes for methane conversion

    SciTech Connect

    Balachandran, U.; Dusek, J.T.; Maiya, P.S.; Ma, B.; Mieville, R.L.; Kleefisch, M.S.; Udovich, C.A.; Fleisch, T.H.

    1995-06-01

    The most significant cost associated with partial oxidation of methane to syngas is that of the oxygen plant. In this paper, the authors offer a technology, based on dense ceramic membranes, that uses air as the oxidant for methane conversion reactions, thus eliminating the need for the oxygen plant. Certain ceramic materials exhibit both electronic and ionic conductivities (of particular interest is oxygen-ion conductivity). These materials transport not only oxygen ions (functioning as selective oxygen separators) but also electrons back from the reactor side to the oxygen/reduction interface. No external electrodes are required, and, if the driving potential of transport is adequate, the partial oxidation reactions should be spontaneous. Such a system will operate without an externally applied potential. Oxygen is transported across the ceramic material in the form of oxygen ions, not oxygen molecules. Recent reports in the literature suggest that dense ceramic membranes made of these mixed conductors can successfully separate oxygen from air at flux rates that could be considered commercially feasible. Thus, these membranes have the potential to improve the economics of methane conversion processes. In principle, the dense ceramic materials can be shaped into hollow-tube reactors, in which air passes over the outside of the membrane and methane flows through the inside. The surfaces can also be reversed. The membrane is permeable to oxygen at high temperatures, but not to nitrogen or other gases. Thus, only oxygen from air can be transported through the membrane to the inside of the reactor surface, where it reacts with methane. Other geometric forms, such as honeycombs or corrugations, of the reactor are possible and can provide substantially greater surface areas for reaction.

  15. Modeling the multiphase flow in a dense medium cyclone

    SciTech Connect

    Wang, B.; Chu, K.W.; Yu, A.B.; Vince, A.

    2009-04-15

    A mathematical model is proposed to describe the multiphase flow in a dense-medium cyclone (DMC). In this model, the volume of fluid multiphase model is first used to determine the shape and position of the air core, and then the mixture multiphase model is employed to describe the flow of the dense medium (comprising finely ground magnetite in water) and the air core, where the turbulence is described by the Reynolds stress model. The results of fluid flow are finally used in the simulation of coal particle flow described by the stochastic Lagrangian particle tracking model. The validity of the proposed approach is verified by the reasonably good agreement between the measured and predicted results under different conditions. The flow features in a DMC are then examined in terms of factors such as flow field, pressure drop, particle trajectories, and separation efficiency. The results are used to explain the key characteristics of flow in DMCs, such as the origin of a short-circuit flow, the flow pattern, and the motion of coal particles. Moreover, the so-called surging phenomenon is examined in relation to the instability of fluid flow. The model offers a convenient method to investigate the effects of variables related to geometrical and operational conditions on the performance of DMCs.

  16. Understanding neutron production in the deuterium dense plasma focus

    SciTech Connect

    Appelbe, Brian E-mail: j.chittenden@imperial.ac.uk; Chittenden, Jeremy E-mail: j.chittenden@imperial.ac.uk

    2014-12-15

    The deuterium Dense Plasma Focus (DPF) can produce copious amounts of MeV neutrons and can be used as an efficient neutron source. However, the mechanism by which neutrons are produced within the DPF is poorly understood and this limits our ability to optimize the device. In this paper we present results from a computational study aimed at understanding how neutron production occurs in DPFs with a current between 70 kA and 500 kA and which parameters can affect it. A combination of MHD and kinetic tools are used to model the different stages of the DPF implosion. It is shown that the anode shape can significantly affect the structure of the imploding plasma and that instabilities in the implosion lead to the generation of large electric fields at stagnation. These electric fields can accelerate deuterium ions within the stagnating plasma to large (>100 keV) energies leading to reactions with ions in the cold dense plasma. It is shown that the electromagnetic fields present can significantly affect the trajectories of the accelerated ions and the resulting neutron production.

  17. Coalescence preference in densely packed microbubbles

    PubMed Central

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-01

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. The surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter. PMID:25583640

  18. Supplemental screening sonography in dense breasts.

    PubMed

    Berg, Wendie A

    2004-09-01

    In single-center trials across 42,838 examinations, 150 (0.35%) cancers were identified only sonographically in average-risk women. Over 90% of the 126 women with sonographically depicted cancers had dense or heterogeneously dense parenchyma. Of the 150 cancers, 141 (94%) were invasive, with a mean size of 9 to 11 mm across the series. Over 90% were node-negative. A3-year multicenter trial of screening sonography in high-risk women, blinded to the results of mammography, opened for enrollment April 2004,funded by the Avon Foundation and National Cancer Institute through the American College of Radiology Imaging Network (ACRIN Protocol 6666). If the trial is successful,the results will provide a rational basis for supplemental screening sonography in women with dense breasts. PMID:15337420

  19. Coalescence preference in densely packed microbubbles

    SciTech Connect

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-13

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. Thus, the surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubbles shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter.

  20. Coalescence preference in densely packed microbubbles

    DOE PAGESBeta

    Kim, Yeseul; Lim, Su Jin; Gim, Bopil; Weon, Byung Mook

    2015-01-13

    A bubble merged from two parent bubbles with different size tends to be placed closer to the larger parent. This phenomenon is known as the coalescence preference. Here we demonstrate that the coalescence preference can be blocked inside a densely packed cluster of bubbles. We utilized high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence events inside densely packed microbubbles with a local packing fraction of ~40%. Thus, the surface energy release theory predicts an exponent of 5 in a relation between the relative coalescence position and the parent size ratio, whereas our observation for coalescence in densely packed microbubblesmore » shows a different exponent of 2. We believe that this result would be important to understand the reality of coalescence dynamics in a variety of packing situations of soft matter.« less

  1. [Metabolic syndrome and small dense LDL].

    PubMed

    Yoshino, Gen

    2006-12-01

    Due to the recent westernization of our lifestyle, it is speculated that the prevalence of metabolic syndrome in the young generation will increase in Japan. Different from Western populations, because of our lifestyle as "farmers" from ancient times, excess energy has been stored outside of the body, and the accumulation of visceral fat might have serious adverse effects on glucose and lipid metabolism. Therefore, we must carefully diagnose and treat patients with metabolic syndrome, which is diagnosed based on the existence of visceral obesity. On the other hand, much attention has been paid recently to the atherogenicity of small dense LDL. In this chapter I will introduce a newly established method for estimating the plasma concentration of small dense LDL-cholesterol. Furthermore, the relationship between subclinical atherosclerosis and small dense LDL in metabolic syndrome will be discussed. PMID:17265899

  2. Elemental: a new framework for distributed memory dense matrix computations.

    SciTech Connect

    Romero, N.; Poulson, J.; Marker, B.; Hammond, J.; Van de Geijn, R.

    2012-02-14

    Parallelizing dense matrix computations to distributed memory architectures is a well-studied subject and generally considered to be among the best understood domains of parallel computing. Two packages, developed in the mid 1990s, still enjoy regular use: ScaLAPACK and PLAPACK. With the advent of many-core architectures, which may very well take the shape of distributed memory architectures within a single processor, these packages must be revisited since the traditional MPI-based approaches will likely need to be extended. Thus, this is a good time to review lessons learned since the introduction of these two packages and to propose a simple yet effective alternative. Preliminary performance results show the new solution achieves competitive, if not superior, performance on large clusters.

  3. Dense Matter Characterization by X-ray Thomson Scattering

    SciTech Connect

    Landen, O L; Glenzer, S H; Edwards, M J; Lee, R W; Collins, G W; Cauble, R C; Hsing, W W; Hammel, B A

    2000-12-29

    We discuss the extension of the powerful technique of Thomson scattering to the x-ray regime for providing an independent measure of plasma parameters for dense plasmas. By spectrally-resolving the scattering, the coherent (Rayleigh) unshifted scattering component can be separated from the incoherent Thomson component, which is both Compton and Doppler shifted. The free electron density and temperature can then be inferred from the spectral shape of the high frequency Thomson scattering component. In addition, as the plasma temperature is decreased, the electron velocity distribution as measured by incoherent Thomson scattering will make a transition from the traditional Gaussian Boltzmann distribution to a density-dependent parabolic Fermi distribution to. We also present a discussion for a proof-of-principle experiment appropriate for a high energy laser facility.

  4. Characterizing dense suspensions: two case studies from the pharmaceutical industry

    NASA Astrophysics Data System (ADS)

    Goldfarb, David J.; Khawaja, Nazia; Kazakevich, Irina; Bhattacharjee, Himanshu; Heslinga, Michael; Dalton, Chad

    2015-11-01

    Liquid suspensions of Active Pharmaceutical Ingredient powders are present as pharmaceutical dosage forms in the form of oral suspensions and injectables. We present two case studies, both dense (~ 30-40%) suspensions, in which the physical characterization of the product, specifically, particle size & shape and rheology were key to understanding the key product attributes as pertaining to the manufacturing process and to patient administration. For the one case study, an oral suspension, identifying variations in particle morphology during the wet milling of the product was key to the product understanding necessary to modify the milling process. Rheological measurements were applied as well. For the second case study, an injectable, results from different particle size measurement techniques and rheological measurements indicated the possibility of flocculation in a formulation. Additionally, measurements were obtained to assess the ``injectability'' of the product via rheometer and texture analyzer measurements and Poiseuille flow modeling. As a result, the relevant shear rate regime for this drug product administration was identified.

  5. Dense packing: surgical indications and technical considerations.

    PubMed

    Farjo, Bessam; Farjo, Nilofer

    2013-08-01

    Dense packing is the philosophy of fitting more than 30 to 35 follicular unit grafts per square centimeter in one operation. The aim is to produce a more even, consistent, and natural looking flow of hair after just one procedure. Although desirable in principle, not all patients are suitable candidates nor is it possible to achieve in certain patients (eg, coarse or curly hair). Patients who have sufficient donor availability, reasonably stable hair loss, and high hair-to-skin color ratios are the ideal candidates. The authors highlight their philosophies and strategies for dense packing. PMID:24017984

  6. The Galactic Dense Gas Distribution and Properties

    NASA Astrophysics Data System (ADS)

    Glenn, Jason

    2015-08-01

    As the nearest spiral galaxy, the Milky Way provides a foundation for understanding galactic astrophysics. However, our position within the Galactic plane makes it challenging to decipher the detailed disk structure. The Galactic distribution of dense gas is relatively poorly known; thus, it is difficult to assess models of galaxy evolution by comparison to the Milky Way. Furthermore, fundamental aspects of star formation remain unknown, such as why the stellar and star cluster initial mass functions appear to be ubiquitous.Sub/millimeter dust continuum surveys, coupled with molecular gas surveys, are revealing the 3D distribution and properties of dense, star-forming gas throughout the disk. Here we report on the use of BGPS and Hi-GAL. BGPS is a 1.1 mm survey of the 1st Galactic quadrant and some lines of sight in the 2nd quadrant, totalling 200 deg2. We developed a technique using the Galactic rotation curve to derive distance probability density functions (DPDFs) to molecular cloud structures identified with continuum surveys. DPDFs combine vLSR measures from dense gas tracers and 13CO with distance discriminators, such as 8 μm extinction, HI self absorption, and (l, b, vLSR) associations with objects of known distances. Typical uncertainties are σdist ≤ 1 kpc for 1,710 BGPS objects with well-constrained distances.From DPDFs we derived the dense gas distribution and the dense gas mass function. We find evidence for dense gas in and between putative spiral arms. A log-normal distribution describes the mass function, which ranges from cores to clouds, but is primarily comprised of clumps. High-mass power laws do not fit the entire data set well, although power-law behavior emerges for sources nearer than 6.5 kpc (α = 2.0±0.1) and for objects between 2 kpc and 10 kpc (α = 1.9±0.1). The power law indices are generally between those of GMC and the stellar IMF. We have begun to apply this approach to the Hi-GAL (70 - 500 μm). With coverage of the entire

  7. Development of a cryogenic EOS capability for the Z Pulsed Radiation Source: Goals and accomplishments of FY97 LDRD project

    SciTech Connect

    Hanson, D.L.; Johnston, R.R.; Asay, J.R.

    1998-03-01

    Experimental cryogenic capabilities are essential for the study of ICF high-gain target and weapons effects issues involving dynamic materials response at low temperatures. This report describes progress during the period 2/97-11/97 on the FY97 LDRD project ``Cryogenic EOS Capabilities on Pulsed Radiation Sources (Z Pinch)``. The goal of this project is the development of a general purpose cryogenic target system for precision EOS and shock physics measurements at liquid helium temperatures on the Z accelerator Z-pinch pulsed radiation source. Activity during the FY97 LDRD phase of this project has focused on development of a conceptual design for the cryogenic target system based on consideration of physics, operational, and safety issues, design and fabrication of principal system components, construction and instrumentation of a cryogenic test facility for off-line thermal and optical testing at liquid helium temperatures, initial thermal testing of a cryogenic target assembly, and the design of a cryogenic system interface to the Z pulsed radiation source facility. The authors discuss these accomplishments as well as elements of the project that require further work.

  8. Vapor-liquid phase behavior of the iodine-sulfur water-splitting process : LDRD final report for FY03.

    SciTech Connect

    Bradshaw, Robert W.; Larson, Richard S.; Lutz, Andrew E.

    2004-01-01

    This report summarizes the results of a one-year LDRD project that was undertaken to better understand the equilibrium behavior of the iodine-water-hydriodic acid system at elevated temperature and pressure. We attempted to extend the phase equilibrium database for this system in order to facilitate development of the iodine-sulfur water-splitting process to produce hydrogen to a commercial scale. The iodine-sulfur cycle for thermochemical splitting of water is recognized as the most efficient such process and is particularly well suited to coupling to a high-temperature source of process heat. This study intended to combine experimental measurements of vapor-liquid-liquid equilibrium and equation-of-state modeling of equilibrium solutions using Sandia's Chernkin software. Vapor-liquid equilibrium experiments were conducted to a limited extent. The Liquid Chernkin software that was developed as part of an earlier LDRD project was enhanced and applied to model the non-ideal behavior of the liquid phases.

  9. Final report on LDRD project 105967 : exploring the increase in GaAs photodiode responsivity with increased neutron fluence.

    SciTech Connect

    Blansett, Ethan L.; Geib, Kent Martin; Cich, Michael Joseph; Wrobel, Theodore Frank; Peake, Gregory Merwin; Fleming, Robert M.; Serkland, Darwin Keith; Wrobel, Diana L.

    2008-01-01

    A previous LDRD studying radiation hardened optoelectronic components for space-based applications led to the result that increased neutron irradiation from a fast-burst reactor caused increased responsivity in GaAs photodiodes up to a total fluence of 4.4 x 10{sup 13} neutrons/cm{sup 2} (1 MeV Eq., Si). The silicon photodiodes experienced significant degradation. Scientific literature shows that neutrons can both cause defects as well as potentially remove defects in an annealing-like process in GaAs. Though there has been some modeling that suggests how fabrication and radiation-induced defects can migrate to surfaces and interfaces in GaAs and lead to an ordering effect, it is important to consider how these processes affect the performance of devices, such as the basic GaAs p-i-n photodiode. In this LDRD, we manufactured GaAs photodiodes at the MESA facility, irradiated them with electrons and neutrons at the White Sands Missile Range Linac and Fast Burst Reactor, and performed measurements to show the effect of irradiation on dark current, responsivity and high-speed bandwidth.

  10. Radiative properties of hot dense matter III. Proceedings. Meeting on Radiative Properties of Hot Dense Matter 1996.

    NASA Astrophysics Data System (ADS)

    Lee, R. W.

    1997-12-01

    The papers consider the radiative properties of hot dense matter. Numerous contributions were directed at understanding the behavior of plasma not in local thermodynamics equilibrium (NLTE). Contributors have analyzed warm dense matter, inertial confinement fusion implosion cores, femtosecond pulse laser generated plasmas, colliding plasmas, and nanosecond long pulse laser generated plasmas. In all of these reports the level of sophistication is advanced, with effects of nonMaxwellian distributions, laser modified transitions, polarization effects and mind-numbing atomic structure models being presented. To ascertain the validity of these NLTE kinetics codes two kinetics code comparisons are reported, which attempt to provide insight into the workings of the kinetics models. The LTE work is directed largely towards the area of opacity studies where both experimental and theoretical efforts were reported. Moreover, the topics of spectral line shapes and the plasma microfields, are given a strong airing. Recent advances and the addition of new effects including magnetic fields, laser pumping, and continuum perturbing states are presented. Finally, many of the contributors present a detailed discussion of the instrumentation which are central to the spectroscopy, providing new paths for future experimental and theoretical advances.

  11. Superordinate Shape Classification Using Natural Shape Statistics

    ERIC Educational Resources Information Center

    Wilder, John; Feldman, Jacob; Singh, Manish

    2011-01-01

    This paper investigates the classification of shapes into broad natural categories such as "animal" or "leaf". We asked whether such coarse classifications can be achieved by a simple statistical classification of the shape skeleton. We surveyed databases of natural shapes, extracting shape skeletons and tabulating their parameters within each…

  12. Scrape-Off-Layer Flow Studies in Tokamaks: Final Report of LDRD Project 09-ERD-025

    SciTech Connect

    Rognlien, T D; Allen, S L; Ellis, R M; Porter, G D; Nam, S K; Weber, T R; Umansky, M V; Howard, J

    2011-11-21

    A summary is given of the work carried out under the LDRD project 09-ERD-025 entitled Scrape-Off-Layer Flow Studies in Tokamaks. This project has lead to implementation of the new prototype Fourier Transform Spectrometer edge plasma flow diagnostic on the DIII-D National Fusion Facility at General Atomics, acquisition of carbon impurity concentration and flow data, and demonstration that the resulting data compare reasonably well with LLNL's edge plasma transport code UEDGE. Details of the work are contained in attached published papers, while the most recent results that are being written-up for publication are summarized in the report. Boundary plasma flows in tokamak fusion devices are key in determining the distribution of fuel and impurity ions, with tritium build-up in the walls an especially critical operational issue. The intrusion of impurity ions to the hot plasma core region can result in serious energy-loss owing to line radiation. However, flow diagnostic capability has been severely limited in fusion-relevant hot edge plasmas where Langmuir-type probes cannot withstand the high heat flux and traditional Doppler spectroscopy has limited resolution and signal strength. Thus, new edge plasma flow diagnostic capabilities need to be developed that can be used in existing and future devices such as ITER. The understanding of such flows requires simulation with 2-dimensional transport codes owing to the geometrical complexity of the edge region in contact with material surfaces and the large number of interaction physical processes including plasma flow along and across the magnetic field, and coupling between impurity and neutral species. The characteristics of edge plasma flows are substantially affected by cross-magnetic-field drifts (ExB/B{sup 2} and BxVB/B{sup 2}), which are known to introduce substantial convergence difficulty for some cases. It is important that these difficulties be overcome so that drifts can be included in transport models, both

  13. LDRD final report on massively-parallel linear programming : the parPCx system.

    SciTech Connect

    Parekh, Ojas; Phillips, Cynthia Ann; Boman, Erik Gunnar

    2005-02-01

    This report summarizes the research and development performed from October 2002 to September 2004 at Sandia National Laboratories under the Laboratory-Directed Research and Development (LDRD) project ''Massively-Parallel Linear Programming''. We developed a linear programming (LP) solver designed to use a large number of processors. LP is the optimization of a linear objective function subject to linear constraints. Companies and universities have expended huge efforts over decades to produce fast, stable serial LP solvers. Previous parallel codes run on shared-memory systems and have little or no distribution of the constraint matrix. We have seen no reports of general LP solver runs on large numbers of processors. Our parallel LP code is based on an efficient serial implementation of Mehrotra's interior-point predictor-corrector algorithm (PCx). The computational core of this algorithm is the assembly and solution of a sparse linear system. We have substantially rewritten the PCx code and based it on Trilinos, the parallel linear algebra library developed at Sandia. Our interior-point method can use either direct or iterative solvers for the linear system. To achieve a good parallel data distribution of the constraint matrix, we use a (pre-release) version of a hypergraph partitioner from the Zoltan partitioning library. We describe the design and implementation of our new LP solver called parPCx and give preliminary computational results. We summarize a number of issues related to efficient parallel solution of LPs with interior-point methods including data distribution, numerical stability, and solving the core linear system using both direct and iterative methods. We describe a number of applications of LP specific to US Department of Energy mission areas and we summarize our efforts to integrate parPCx (and parallel LP solvers in general) into Sandia's massively-parallel integer programming solver PICO (Parallel Interger and Combinatorial Optimizer). We

  14. FY07 LDRD Final Report Synthesis under High Pressure and Temperature of New Metal Nitrides

    SciTech Connect

    Crowhurst, J C; Sadigh, B; Aberg, D; Zaug, J M; Goncharov, A F

    2008-09-23

    The original aim of this LDRD was to determine with unprecedented precision the melting curve of iron to geophysically relevant pressures. In the course of developing much of the technology and techniques required to obtain this information we have encountered and studied novel chemical reactions some of whose products are stable or metastable under ambient conditions. Specifically we have synthesized nitrides of the platinum group metals including platinum, iridium, and palladium. We have also carried out in depth first principles theoretical investigations into the nature of these materials. We believed that the scientific impact of continuing this work would be greater than that of the original goals of this project. Indeed the work has led to a number of high profile publications with additional publications in preparation. While nitrides of the transition metals are generally of tremendous technological importance, those of the noble metals in particular have enjoyed much experimental and theoretical attention in the very short time since they were first synthesized. The field was and clearly remains open for further study. While the scientific motivation for this research is different from that originally proposed, many of the associated methods in which we have now gained experience are similar or identical. These include use of the diamond anvil cell combined with technologies to generate high temperatures, the in-situ technique of Raman scattering using our purpose-built, state-of-the-art system, analytical techniques for determining the composition of recovered samples such as x-ray photoelectron spectroscopy, and finally synchrotron-based techniques such as x-ray diffraction for structural and equation of state determinations. Close interactions between theorists and experimentalists has and will continue to allow our group to rapidly and reliably interpret complicated results on the structure and dynamics of these compounds and also additional novel

  15. Reduced order models for thermal analysis : final report : LDRD Project No. 137807.

    SciTech Connect

    Hogan, Roy E., Jr.; Gartling, David K.

    2010-09-01

    This LDRD Senior's Council Project is focused on the development, implementation and evaluation of Reduced Order Models (ROM) for application in the thermal analysis of complex engineering problems. Two basic approaches to developing a ROM for combined thermal conduction and enclosure radiation problems are considered. As a prerequisite to a ROM a fully coupled solution method for conduction/radiation models is required; a parallel implementation is explored for this class of problems. High-fidelity models of large, complex systems are now used routinely to verify design and performance. However, there are applications where the high-fidelity model is too large to be used repetitively in a design mode. One such application is the design of a control system that oversees the functioning of the complex, high-fidelity model. Examples include control systems for manufacturing processes such as brazing and annealing furnaces as well as control systems for the thermal management of optical systems. A reduced order model (ROM) seeks to reduce the number of degrees of freedom needed to represent the overall behavior of the large system without a significant loss in accuracy. The reduction in the number of degrees of freedom of the ROM leads to immediate increases in computational efficiency and allows many design parameters and perturbations to be quickly and effectively evaluated. Reduced order models are routinely used in solid mechanics where techniques such as modal analysis have reached a high state of refinement. Similar techniques have recently been applied in standard thermal conduction problems e.g. though the general use of ROM for heat transfer is not yet widespread. One major difficulty with the development of ROM for general thermal analysis is the need to include the very nonlinear effects of enclosure radiation in many applications. Many ROM methods have considered only linear or mildly nonlinear problems. In the present study a reduced order model is

  16. SUPPORTED DENSE CERAMIC MEMBRANES FOR OXYGEN SEPARATION

    SciTech Connect

    Timothy L. Ward

    2002-07-01

    Mixed-conducting ceramics have the ability to conduct oxygen with perfect selectivity at elevated temperatures, making them extremely attractive as membrane materials for oxygen separation and membrane reactor applications. While the conductivity of these materials can be quite high at elevated temperatures (typically 800-1000 C), much higher oxygen fluxes, or, alternatively, equivalent fluxes at lower temperatures, could be provided by supported thin or thick film membrane layers. Based on that motivation, the objective of this project was to explore the use of ultrafine aerosol-derived powder of a mixed-conducting ceramic material for fabrication of supported thick-film dense membranes. The project focused on the mixed-conducting ceramic composition SrCo{sub 0.5}FeO{sub x} (SCFO) because of the desirable permeability and stability of that material, as reported in the literature. Appropriate conditions to produce the submicron SrCo{sub 0.5}FeO{sub x} powder using aerosol pyrolysis were determined. Porous supports of the same composition were produced by partial sintering of a commercially obtained powder that possessed significantly larger particle size than the aerosol-derived powder. The effects of sintering conditions (temperature, atmosphere) on the porosity and microstructure of the porous discs were studied, and a standard support fabrication procedure was adopted. Subsequently, a variety of paste and slurry formulations were explored utilizing the aerosol-derived SCFO powder. These formulations were applied to the porous SCFO support by a doctor blade or spin coating procedure. Sintering of the supported membrane layer was then conducted, and additional layers were deposited and sintered in some cases. The primary characterization methods were X-ray diffraction and scanning electron microscopy, and room-temperature nitrogen permeation was used to assess defect status of the membranes.We found that non-aqueous paste/slurry formulations incorporating

  17. The Southern California Dense GPS Geodetic Array

    NASA Technical Reports Server (NTRS)

    Webb, F.

    1994-01-01

    The Southern California Earthquake Center is coordinating a effort by scientists at the Jet Propulsion Laboratory, the U.S. Geological Survey, and various academic institutions to establish a dense 250 station, continuously recording GPS geodetic array in southern California for measuring crustal deformation associated with slip on the numerous faults that underlie the major metropolitan areas of southern california.

  18. Coalescence preference in dense packing of bubbles

    NASA Astrophysics Data System (ADS)

    Kim, Yeseul; Gim, Bopil; Gim, Bopil; Weon, Byung Mook

    2015-11-01

    Coalescence preference is the tendency that a merged bubble from the contact of two original bubbles (parent) tends to be near to the bigger parent. Here, we show that the coalescence preference can be blocked by densely packing of neighbor bubbles. We use high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence phenomenon which occurs in micro scale seconds and inside dense packing of microbubbles with a local packing fraction of ~40%. Previous theory and experimental evidence predict a power of -5 between the relative coalescence position and the parent size. However, our new observation for coalescence preference in densely packed microbubbles shows a different power of -2. We believe that this result may be important to understand coalescence dynamics in dense packing of soft matter. This work (NRF-2013R1A22A04008115) was supported by Mid-career Researcher Program through NRF grant funded by the MEST and also was supported by Ministry of Science, ICT and Future Planning (2009-0082580) and by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry and Education, Science and Technology (NRF-2012R1A6A3A04039257).

  19. Dense high temperature ceramic oxide superconductors

    DOEpatents

    Landingham, R.L.

    1993-10-12

    Dense superconducting ceramic oxide articles of manufacture and methods for producing these articles are described. Generally these articles are produced by first processing these superconducting oxides by ceramic processing techniques to optimize materials properties, followed by reestablishing the superconducting state in a desired portion of the ceramic oxide composite.

  20. Dense high temperature ceramic oxide superconductors

    DOEpatents

    Landingham, Richard L.

    1993-01-01

    Dense superconducting ceramic oxide articles of manufacture and methods for producing these articles are described. Generally these articles are produced by first processing these superconducting oxides by ceramic processing techniques to optimize materials properties, followed by reestablishing the superconducting state in a desired portion of the ceramic oxide composite.

  1. DENSE NONAQUEOUS PHASE LIQUIDS -- A WORKSHOP SUMMARY

    EPA Science Inventory

    site characterization, and, therefore, DNAPL remediation, can be expected. Dense nonaqueous phase liquids (DNAPLs) in the subsurface are long-term sources of ground-water contamination, and may persist for centuries before dissolving completely in adjacent ground water. In respo...

  2. Preparation of a dense, polycrystalline ceramic structure

    DOEpatents

    Cooley, Jason; Chen, Ching-Fong; Alexander, David

    2010-12-07

    Ceramic nanopowder was sealed inside a metal container under a vacuum. The sealed evacuated container was forced through a severe deformation channel at an elevated temperature below the melting point of the ceramic nanopowder. The result was a dense nanocrystalline ceramic structure inside the metal container.

  3. Effect of dense phase of fluidized bed pyrolyzer on the devolatilization behavior of coal

    SciTech Connect

    Li Haibin; Chen Yong; Wang Yang

    1998-12-31

    Pyrolysis of coal in fluidized beds were investigated by many researchers. The results of both experiments and model simulations were published. However, there are deviations between the results of different researchers; one of the most important reasons is that the designated features of there experimental devices are different. For example, different freeboard temperature or height will lead to different product compositions. In this paper, the effect of dense phase of fluidized bed on product distribution is discussed when the effect of freeboard is minimized. Shenmu coal ({minus}45 + 80 mesh) was pyrolyzed in a special designed fluidized bed reactor with I.D. of 48mm and a cone-shaped distributor. The temperature of dense phase and freeboard can be controlled respectively. The relationship between gas phase product yield and dense phase temperature was obtained. The results show that the yields of H{sub 2}, CO, CH{sub 4} and C{sub 2}H{sub 4} increase dramatically with increasing dense phase temperature. However, liquid yield reaches the maximum in the dense phase temperature range of 600--650 C. By comparing with the results of former researchers, it can be seen that the volatile can undergo serious secondary reactions when the freeboard temperature is high, even when the residence time is very short. The results of this paper are believed to represent the more accurate trend of the effect of bed temperature on gas phase product yield because the vapor phase secondary reactions were minimized in this experiment.

  4. The Distribution of YSO Masses in Dense Hubs and Less Dense Filaments

    NASA Astrophysics Data System (ADS)

    Kirk, Helen; Myers, P.

    2010-01-01

    Dense "hubs" and less dense radiating "filaments" are common features of nearby star-forming regions and infrared dark clouds. Cores and young stars are more concentrated in such hubs than in their radiating filaments. Accreting protostars may gain less mass in such low-density filaments, since low-density gas takes longer to accrete, and since the accretion must draw gas from a greater distance in filamentary geometry. We present an investigation of the mass distributions of YSOs in dense clusters and low-density filaments in the nearest molecular clouds, to test whether YSO masses depend on environment density and geometry. HK is supported by an NSERC PDF.

  5. Maximally dense packings of two-dimensional convex and concave noncircular particles

    NASA Astrophysics Data System (ADS)

    Atkinson, Steven; Jiao, Yang; Torquato, Salvatore

    2012-09-01

    Dense packings of hard particles have important applications in many fields, including condensed matter physics, discrete geometry, and cell biology. In this paper, we employ a stochastic search implementation of the Torquato-Jiao adaptive-shrinking-cell (ASC) optimization scheme [Nature (London)NATUAS0028-083610.1038/nature08239 460, 876 (2009)] to find maximally dense particle packings in d-dimensional Euclidean space Rd. While the original implementation was designed to study spheres and convex polyhedra in d≥3, our implementation focuses on d=2 and extends the algorithm to include both concave polygons and certain complex convex or concave nonpolygonal particle shapes. We verify the robustness of this packing protocol by successfully reproducing the known putative optimal packings of congruent copies of regular pentagons and octagons, then employ it to suggest dense packing arrangements of congruent copies of certain families of concave crosses, convex and concave curved triangles (incorporating shapes resembling the Mercedes-Benz logo), and “moonlike” shapes. Analytical constructions are determined subsequently to obtain the densest known packings of these particle shapes. For the examples considered, we find that the densest packings of both convex and concave particles with central symmetry are achieved by their corresponding optimal Bravais lattice packings; for particles lacking central symmetry, the densest packings obtained are nonlattice periodic packings, which are consistent with recently-proposed general organizing principles for hard particles. Moreover, we find that the densest known packings of certain curved triangles are periodic with a four-particle basis, and we find that the densest known periodic packings of certain moonlike shapes possess no inherent symmetries. Our work adds to the growing evidence that particle shape can be used as a tuning parameter to achieve a diversity of packing structures.

  6. Maximally dense packings of two-dimensional convex and concave noncircular particles.

    PubMed

    Atkinson, Steven; Jiao, Yang; Torquato, Salvatore

    2012-09-01

    Dense packings of hard particles have important applications in many fields, including condensed matter physics, discrete geometry, and cell biology. In this paper, we employ a stochastic search implementation of the Torquato-Jiao adaptive-shrinking-cell (ASC) optimization scheme [Nature (London) 460, 876 (2009)] to find maximally dense particle packings in d-dimensional Euclidean space R(d). While the original implementation was designed to study spheres and convex polyhedra in d≥3, our implementation focuses on d=2 and extends the algorithm to include both concave polygons and certain complex convex or concave nonpolygonal particle shapes. We verify the robustness of this packing protocol by successfully reproducing the known putative optimal packings of congruent copies of regular pentagons and octagons, then employ it to suggest dense packing arrangements of congruent copies of certain families of concave crosses, convex and concave curved triangles (incorporating shapes resembling the Mercedes-Benz logo), and "moonlike" shapes. Analytical constructions are determined subsequently to obtain the densest known packings of these particle shapes. For the examples considered, we find that the densest packings of both convex and concave particles with central symmetry are achieved by their corresponding optimal Bravais lattice packings; for particles lacking central symmetry, the densest packings obtained are nonlattice periodic packings, which are consistent with recently-proposed general organizing principles for hard particles. Moreover, we find that the densest known packings of certain curved triangles are periodic with a four-particle basis, and we find that the densest known periodic packings of certain moonlike shapes possess no inherent symmetries. Our work adds to the growing evidence that particle shape can be used as a tuning parameter to achieve a diversity of packing structures. PMID:23030907

  7. Dense hadronic matter in holographic QCD

    NASA Astrophysics Data System (ADS)

    Kim, Keun-Young; Sin, Sang-Jin; Zahed, Ismail

    2013-10-01

    We provide a method to study hadronic matter at finite density in the context of the Sakai-Sugimoto model. We introduce the baryon chemical potential through the external U(1) v gauge field in the induced (DBI plus CS) action on the D8-probe-brane, where baryons are skyrmions. Vector dominance is manifest at finite density. We derive the effect of the baryon density on the energy density, and on the dispersion relations of pions and vector mesons at large N c . The energy density asymptotes are constant at large density, suggesting that dense matter at large N c freezes, with the pion velocity dropping to zero. Holographic dense matter enforces exactly the tenets of vector dominance and efficiently screens vector mesons. At the freezing point, the ρ — ππ coupling vanishes with a finite rho mass of about 20% its vacuum value.

  8. The kinetic chemistry of dense interstellar clouds

    NASA Technical Reports Server (NTRS)

    Graedel, T. E.; Langer, W. D.; Frerking, M. A.

    1982-01-01

    A model of the time-dependent chemistry of dense interstellar clouds is formulated to study the dominant chemical processes in carbon and oxygen isotope fractionation, the formation of nitrogen-containing molecules, and the evolution of product molecules as a function of cloud density and temperature. The abundances of the dominant isotopes of the carbon- and oxygen-bearing molecules are calculated. The chemical abundances are found to be quite sensitive to electron concentration since the electron concentration determines the ratio of H3(+) to He(+), and the electron density is strongly influenced by the metals abundance. For typical metal abundances and for H2 cloud density not less than 10,000 molecules/cu cm, nearly all carbon exists as CO at late cloud ages. At high cloud density, many aspects of the chemistry are strongly time dependent. Finally, model calculations agree well with abundances deduced from observations of molecular line emission in cold dense clouds.

  9. Hydrodynamic stellar interactions in dense star clusters

    NASA Technical Reports Server (NTRS)

    Rasio, Frederic A.

    1993-01-01

    Highly detailed HST observations of globular-cluster cores and galactic nuclei motivate new theoretical studies of the violent dynamical processes which govern the evolution of these very dense stellar systems. These processes include close stellar encounters and direct physical collisions between stars. Such hydrodynamic stellar interactions are thought to explain the large populations of blue stragglers, millisecond pulsars, X-ray binaries, and other peculiar sources observed in globular clusters. Three-dimensional hydrodynamics techniques now make it possible to perform realistic numerical simulations of these interactions. The results, when combined with those of N-body simulations of stellar dynamics, should provide for the first time a realistic description of dense star clusters. Here I review briefly current theoretical work on hydrodynamic stellar interactions, emphasizing its relevance to recent observations.

  10. Active fluidization in dense glassy systems.

    PubMed

    Mandal, Rituparno; Bhuyan, Pranab Jyoti; Rao, Madan; Dasgupta, Chandan

    2016-07-20

    Dense soft glasses show strong collective caging behavior at sufficiently low temperatures. Using molecular dynamics simulations of a model glass former, we show that the incorporation of activity or self-propulsion, f0, can induce cage breaking and fluidization, resulting in the disappearance of the glassy phase beyond a critical f0. The diffusion coefficient crosses over from being strongly to weakly temperature dependent as f0 is increased. In addition, we demonstrate that activity induces a crossover from a fragile to a strong glass and a tendency of active particles to cluster. Our results are of direct relevance to the collective dynamics of dense active colloidal glasses and to recent experiments on tagged particle diffusion in living cells. PMID:27380935

  11. Dense Molecular Gas in Centaurus A

    NASA Astrophysics Data System (ADS)

    Wild, Wolfgang; Eckart, Andreas

    1999-10-01

    Centaurus A (NGC 5128) is the closest radio galaxy, and its molecular interstellar medium has been studied extensively in recent years. However, these studies used mostly molecular lines tracing low to medium density gas (see e.g. Eckart et al. 1990. Wild et al. 1997). The amount and distribution of the dense component remained largely unknown. We present spectra of the HCN(1-0) emission - which traces dense (n(H2) > 104 cm-3) molecular gas - at the center and along the prominent dust lane at offset positions +/- 60" and +/- 100", as well as single CS(2-1) and CS(3-2) spectra, observed with the SEST on La Silla, Chile. At the central position, the integrated intensity ratio I(HCN)/I(CO) peaks at 0.064, and decreases to somewhat equal to 0.02 to 0.04 in the dust lane. Based on the line luminosity ratio L(HCN)/L(CO) we estimate that there is a significant amount of dense gas in Centaurus A. The fraction of dense molecular gas as well as the star formation efficiency LFIR/LCO towards the center of Cen A is comparable to ultra-luminous infrared galaxies, and falls in between the values for ULIRGs and normal galaxies for positions in the dust lane. Details will be published in Wild & Eckart (A&A, in prep.). Eckart et al. 1990, ApJ 363, 451 Rydbeck et al. 1993, Astr.Ap. (Letters) 270, L13. Wild, W., Eckart, A. & Wiklind, T. 1997, Astr.Ap. 322, 419.

  12. Computational electromagnetics and parallel dense matrix computations

    SciTech Connect

    Forsman, K.; Kettunen, L.; Gropp, W.; Levine, D.

    1995-06-01

    We present computational results using CORAL, a parallel, three-dimensional, nonlinear magnetostatic code based on a volume integral equation formulation. A key feature of CORAL is the ability to solve, in parallel, the large, dense systems of linear equations that are inherent in the use of integral equation methods. Using the Chameleon and PSLES libraries ensures portability and access to the latest linear algebra solution technology.

  13. Computer codes for dispersion of dense gas

    SciTech Connect

    Weber, A.H.; Watts, J.R.

    1982-02-01

    Two models for describing the behavior of dense gases have been adapted for specific applications at the Savannah River Plant (SRP) and have been programmed on the IBM computer. One of the models has been used to predict the effect of a ruptured H/sub 2/S storage tank at the 400 Area. The other model has been used to simulate the effect of an unignited release of H/sub 2/S from the 400-Area flare tower.

  14. Shear dispersion in dense granular flows

    DOE PAGESBeta

    Christov, Ivan C.; Stone, Howard A.

    2014-04-18

    We formulate and solve a model problem of dispersion of dense granular materials in rapid shear flow down an incline. The effective dispersivity of the depth-averaged concentration of the dispersing powder is shown to vary as the Péclet number squared, as in classical Taylor–Aris dispersion of molecular solutes. An extension to generic shear profiles is presented, and possible applications to industrial and geological granular flows are noted.

  15. Structures for dense, crack free thin films

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2011-03-08

    The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

  16. Dense matter theory: A simple classical approach

    NASA Astrophysics Data System (ADS)

    Savić, P.; Čelebonović, V.

    1994-07-01

    In the sixties, the first author and by P. Savić and R. Kašanin started developing a mean-field theory of dense matter. It is based on the Coulomb interaction, supplemented by a microscopic selection rule and a set of experimentally founded postulates. Applications of the theory range from the calculation of models of planetary internal structure to DAC experiments.

  17. Oxygen ion-conducting dense ceramic

    DOEpatents

    Balachandran, Uthamalingam; Kleefisch, Mark S.; Kobylinski, Thaddeus P.; Morissette, Sherry L.; Pei, Shiyou

    1998-01-01

    Preparation, structure, and properties of mixed metal oxide compositions and their uses are described. Mixed metal oxide compositions of the invention have stratified crystalline structure identifiable by means of powder X-ray diffraction patterns. In the form of dense ceramic membranes, the present compositions demonstrate an ability to separate oxygen selectively from a gaseous mixture containing oxygen and one or more other volatile components by means of ionic conductivities.

  18. Numerical modeling for dilute and dense sprays

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Kim, Y. M.; Shang, H. M.; Ziebarth, J. P.; Wang, T. S.

    1992-01-01

    We have successfully implemented a numerical model for spray-combustion calculations. In this model, the governing gas-phase equations in Eulerian coordinate are solved by a time-marching multiple pressure correction procedure based on the operator-splitting technique. The droplet-phase equations in Lagrangian coordinate are solved by a stochastic discrete particle technique. In order to simplify the calculation procedure for the circulating droplets, the effective conductivity model is utilized. The k-epsilon models are utilized to characterize the time and length scales of the gas phase in conjunction with turbulent modulation by droplets and droplet dispersion by turbulence. This method entails random sampling of instantaneous gas flow properties and the stochastic process requires a large number of computational parcels to produce the satisfactory dispersion distributions even for rather dilute sprays. Two major improvements in spray combustion modelings were made. Firstly, we have developed a probability density function approach in multidimensional space to represent a specific computational particle. Secondly, we incorporate the Taylor Analogy Breakup (TAB) model for handling the dense spray effects. This breakup model is based on the reasonable assumption that atomization and drop breakup are indistinguishable processes within a dense spray near the nozzle exit. Accordingly, atomization is prescribed by injecting drops which have a characteristic size equal to the nozzle exit diameter. Example problems include the nearly homogeneous and inhomogeneous turbulent particle dispersion, and the non-evaporating, evaporating, and burning dense sprays. Comparison with experimental data will be discussed in detail.

  19. Multishock Compression Properties of Warm Dense Argon.

    PubMed

    Zheng, Jun; Chen, Qifeng; Yunjun, Gu; Li, Zhiguo; Shen, Zhijun

    2015-01-01

    Warm dense argon was generated by a shock reverberation technique. The diagnostics of warm dense argon were performed by a multichannel optical pyrometer and a velocity interferometer system. The equations of state in the pressure-density range of 20-150 GPa and 1.9-5.3 g/cm(3) from the first- to fourth-shock compression were presented. The single-shock temperatures in the range of 17.2-23.4 kK were obtained from the spectral radiance. Experimental results indicates that multiple shock-compression ratio (ηi = ρi/ρ0) is greatly enhanced from 3.3 to 8.8, where ρ0 is the initial density of argon and ρi (i = 1, 2, 3, 4) is the compressed density from first to fourth shock, respectively. For the relative compression ratio (ηi' = ρi/ρi-1), an interesting finding is that a turning point occurs at the second shocked states under the conditions of different experiments, and ηi' increases with pressure in lower density regime and reversely decreases with pressure in higher density regime. The evolution of the compression ratio is controlled by the excitation of internal degrees of freedom, which increase the compression, and by the interaction effects between particles that reduce it. A temperature-density plot shows that current multishock compression states of argon have distributed into warm dense regime. PMID:26515505

  20. Dense spray evaporation as a mixing process

    NASA Astrophysics Data System (ADS)

    de Rivas, A.; Villermaux, E.

    2016-05-01

    We explore the processes by which a dense set of small liquid droplets (a spray) evaporates in a dry, stirred gas phase. A dense spray of micron-sized liquid (water or ethanol) droplets is formed in air by a pneumatic atomizer in a closed chamber. The spray is conveyed in ambient air as a plume whose extension depends on the relative humidity of the diluting medium. Standard shear instabilities develop at the plume edge, forming the stretched lamellar structures familiar with passive scalars. Unlike passive scalars however, these lamellae vanish in a finite time, because individual droplets evaporate at their border in contact with the dry environment. Experiments demonstrate that the lifetime of an individual droplet embedded in a lamellae is much larger than expected from the usual d2 law describing the fate of a single drop evaporating in a quiescent environment. By analogy with the way mixing times are understood from the convection-diffusion equation for passive scalars, we show that the lifetime of a spray lamellae stretched at a constant rate γ is tv=1/γ ln(1/+ϕ ϕ ) , where ϕ is a parameter that incorporates the thermodynamic and diffusional properties of the vapor in the diluting phase. The case of time-dependent stretching rates is examined too. A dense spray behaves almost as a (nonconserved) passive scalar.

  1. Automated building extraction using dense elevation matrices

    NASA Astrophysics Data System (ADS)

    Bendett, A. A.; Rauhala, Urho A.; Pearson, James J.

    1997-02-01

    The identification and measurement of buildings in imagery is important to a number of applications including cartography, modeling and simulation, and weapon targeting. Extracting large numbers of buildings manually can be time- consuming and expensive, so the automation of the process is highly desirable. This paper describes and demonstrates such an automated process for extracting rectilinear buildings from stereo imagery. The first step is the generation of a dense elevation matrix registered to the imagery. In the examples shown, this was accomplished using global minimum residual matching (GMRM). GMRM automatically removes y- parallax from the stereo imagery and produces a dense matrix of x-parallax values which are proportional to the local elevation, and, of course, registered to the imagery. The second step is to form a joint probability distribution of the image gray levels and the corresponding height values from the elevation matrix. Based on the peaks of that distribution, the area of interest is segmented into feature and non-feature areas. The feature areas are further refined using length, width and height constraints to yield promising building hypotheses with their corresponding vertices. The gray shade image is used in the third step to verify the hypotheses and to determine precise edge locations corresponding to the approximate vertices and satisfying appropriate orthogonality constraints. Examples of successful application of this process to imagery are presented, and extensions involving the use of dense elevation matrices from other sources are possible.

  2. Dense Correspondences across Scenes and Scales.

    PubMed

    Tau, Moria; Hassner, Tal

    2016-05-01

    We seek a practical method for establishing dense correspondences between two images with similar content, but possibly different 3D scenes. One of the challenges in designing such a system is the local scale differences of objects appearing in the two images. Previous methods often considered only few image pixels; matching only pixels for which stable scales may be reliably estimated. Recently, others have considered dense correspondences, but with substantial costs associated with generating, storing and matching scale invariant descriptors. Our work is motivated by the observation that pixels in the image have contexts-the pixels around them-which may be exploited in order to reliably estimate local scales. We make the following contributions. (i) We show that scales estimated in sparse interest points may be propagated to neighboring pixels where this information cannot be reliably determined. Doing so allows scale invariant descriptors to be extracted anywhere in the image. (ii) We explore three means for propagating this information: using the scales at detected interest points, using the underlying image information to guide scale propagation in each image separately, and using both images together. Finally, (iii), we provide extensive qualitative and quantitative results, demonstrating that scale propagation allows for accurate dense correspondences to be obtained even between very different images, with little computational costs beyond those required by existing methods. PMID:26336115

  3. Final LDRD report : enhanced spontaneous emission rate in visible III-nitride LEDs using 3D photonic crystal cavities.

    SciTech Connect

    Fischer, Arthur Joseph; Subramania, Ganapathi S.; Coley, Anthony J.; Lee, Yun-Ju; Li, Qiming; Wang, George T.; Luk, Ting Shan; Koleske, Daniel David; Fullmer, Kristine Wanta

    2009-09-01

    The fundamental spontaneous emission rate for a photon source can be modified by placing the emitter inside a periodic dielectric structure allowing the emission to be dramatically enhanced or suppressed depending on the intended application. We have investigated the relatively unexplored realm of interaction between semiconductor emitters and three dimensional photonic crystals in the visible spectrum. Although this interaction has been investigated at longer wavelengths, very little work has been done in the visible spectrum. During the course of this LDRD, we have fabricated TiO{sub 2} logpile photonic crystal structures with the shortest wavelength band gap ever demonstrated. A variety of different emitters with emission between 365 nm and 700 nm were incorporated into photonic crystal structures. Time-integrated and time-resolved photoluminescence measurements were performed to measure changes to the spontaneous emission rate. Both enhanced and suppressed emission were demonstrated and attributed to changes to the photonic density of states.

  4. Characterize and Model Final Waste Formulations and Offgas Solids from Thermal Treatment Processes - FY-98 Final Report for LDRD 2349

    SciTech Connect

    Kessinger, Glen Frank; Nelson, Lee Orville; Grandy, Jon Drue; Zuck, Larry Douglas; Kong, Peter Chuen Sun; Anderson, Gail

    1999-08-01

    The purpose of LDRD #2349, Characterize and Model Final Waste Formulations and Offgas Solids from Thermal Treatment Processes, was to develop a set of tools that would allow the user to, based on the chemical composition of a waste stream to be immobilized, predict the durability (leach behavior) of the final waste form and the phase assemblages present in the final waste form. The objectives of the project were: • investigation, testing and selection of thermochemical code • development of auxiliary thermochemical database • synthesis of materials for leach testing • collection of leach data • using leach data for leach model development • thermochemical modeling The progress toward completion of these objectives and a discussion of work that needs to be completed to arrive at a logical finishing point for this project will be presented.

  5. Hardness Assurance for Low-Energy Proton-Induced Single-Event Effects: Final report for LDRD Project 173134

    SciTech Connect

    Dodds, Nathaniel Anson

    2015-08-01

    This report briefly summarizes three publications that resulted from a two-year LDRD. The three publications address a recently emerging reliability issue: namely, that low-energy protons (LEPs) can cause single-event effects (SEEs) in highly scaled microelectronics. These publications span from low to high technology readiness levels. In the first, novel experiments were used to prove that proton direct ionization is the dominant mechanism for LEP-induced SEEs. In the second, a simple method was developed to calculate expected on-orbit error rates for LEP effects. This simplification was enabled by creating (and characterizing) an accelerated space-like LEP environment in the laboratory. In the third publication, this new method was applied to many memory circuits from the 20-90 nm technology nodes to study the general importance of LEP effects, in terms of their contribution to the total on-orbit SEE rate.

  6. Final LDRD report : nanoscale mechanisms in advanced aging of materials during storage of spent %22high burnup%22 nuclear fuel.

    SciTech Connect

    Clark, Blythe G.; Rajasekhara, Shreyas; Enos, David George; Dingreville, Remi Philippe Michel; Doyle, Barney Lee; Hattar, Khalid Mikhiel; Weiner, Ruth F.

    2013-09-01

    We present the results of a three-year LDRD project focused on understanding microstructural evolution and related property changes in Zr-based nuclear cladding materials towards the development of high fidelity predictive simulations for long term dry storage. Experiments and modeling efforts have focused on the effects of hydride formation and accumulation of irradiation defects. Key results include: determination of the influence of composition and defect structures on hydride formation; measurement of the electrochemical property differences between hydride and parent material for understanding and predicting corrosion resistance; in situ environmental transmission electron microscope observation of hydride formation; development of a predictive simulation for mechanical property changes as a function of irradiation dose; novel test method development for microtensile testing of ionirradiated material to simulate the effect of neutron irradiation on mechanical properties; and successful demonstration of an Idaho National Labs-based sample preparation and shipping method for subsequent Sandia-based analysis of post-reactor cladding.

  7. FY04 LDRD Final Report Stroke Sensor Development Using Microdot Sensor Arrays

    SciTech Connect

    Carter, J C; Wilson, T S; Alvis, R M; Paulson, C N; Setlur, U S; McBride, M T; Brown, S B; Bearinger, J P; Colston, B W

    2005-11-15

    major thrust area for the Medical Technology Program (M-division). Through MTP, LLNL has a sizable investment and recognizable expertise in stroke treatment research. The proposed microdot array sensor for stroke will complement this existing program in which mechanical devices are being designed for removing the thrombus. The following list of stroke projects and their relative status shows that MTP has a proven track record of taking ideas to industry: The goal of this LDRD funded project was to develop and demonstrate a minimally invasive optical fiber-based sensor for rapid and in-vivo measurements of multiple stroke biomarkers (e.g. pH and enzyme). The development of this sensor also required the development of a new fabrication technology for attaching indicator chemistries to optical fibers. A benefit of this work is to provide clinicians with a tool to assess vascular integrity of the region beyond the thrombus to determine whether or not it is safe to proceed with the removal of the clot. Such an assessment could extend the use of thrombolytic drug treatment to acute stroke victims outside the current rigid temporal limitation of 3 hours. Furthermore, this sensor would also provide a tool for use with emerging treatments involving the use of mechanical devices for removing the thrombus. The sensor effectively assesses the risk for reperfusion injury.

  8. Eyeglass Large Aperture, Lightweight Space Optics FY2000 - FY2002 LDRD Strategic Initiative

    SciTech Connect

    Hyde, R

    2003-02-10

    differences in their requirements and implementations, the fundamental difficulty in utilizing large aperture optics is the same for all of these applications: It is extremely difficult to design large aperture space optics which are both optically precise and can meet the practical requirements for launch and deployment in space. At LLNL we have developed a new concept (Eyeglass) which uses large diffractive optics to solve both of these difficulties; greatly reducing both the mass and the tolerance requirements for large aperture optics. During previous LDRD-supported research, we developed this concept, built and tested broadband diffractive telescopes, and built 50 cm aperture diffraction-limited diffractive lenses (the largest in the world). This work is fully described in UCRL-ID-136262, Eyeglass: A Large Aperture Space Telescope. However, there is a large gap between optical proof-of-principle with sub-meter apertures, and actual 50 meter space telescopes. This gap is far too large (both in financial resources and in spacecraft expertise) to be filled internally at LLNL; implementation of large aperture diffractive space telescopes must be done externally using non-LLNL resources and expertise. While LLNL will never become the primary contractor and integrator for large space optical systems, our natural role is to enable these devices by developing the capability of producing very large diffractive optics. Accordingly, the purpose of the Large Aperture, Lightweight Space Optics Strategic Initiative was to develop the technology to fabricate large, lightweight diffractive lenses. The additional purpose of this Strategic Initiative was, of course, to demonstrate this lens-fabrication capability in a fashion compellingly enough to attract the external support necessary to continue along the path to full-scale space-based telescopes. During this 3 year effort (FY2000-FY2002) we have developed the capability of optically smoothing and diffractively-patterning thin meter

  9. Final LDRD report : development of sample preparation methods for ChIPMA-based imaging mass spectrometry of tissue samples.

    SciTech Connect

    Maharrey, Sean P.; Highley, Aaron M.; Behrens, Richard, Jr.; Wiese-Smith, Deneille

    2007-12-01

    The objective of this short-term LDRD project was to acquire the tools needed to use our chemical imaging precision mass analyzer (ChIPMA) instrument to analyze tissue samples. This effort was an outgrowth of discussions with oncologists on the need to find the cellular origin of signals in mass spectra of serum samples, which provide biomarkers for ovarian cancer. The ultimate goal would be to collect chemical images of biopsy samples allowing the chemical images of diseased and nondiseased sections of a sample to be compared. The equipment needed to prepare tissue samples have been acquired and built. This equipment includes an cyro-ultramicrotome for preparing thin sections of samples and a coating unit. The coating unit uses an electrospray system to deposit small droplets of a UV-photo absorbing compound on the surface of the tissue samples. Both units are operational. The tissue sample must be coated with the organic compound to enable matrix assisted laser desorption/ionization (MALDI) and matrix enhanced secondary ion mass spectrometry (ME-SIMS) measurements with the ChIPMA instrument Initial plans to test the sample preparation using human tissue samples required development of administrative procedures beyond the scope of this LDRD. Hence, it was decided to make two types of measurements: (1) Testing the spatial resolution of ME-SIMS by preparing a substrate coated with a mixture of an organic matrix and a bio standard and etching a defined pattern in the coating using a liquid metal ion beam, and (2) preparing and imaging C. elegans worms. Difficulties arose in sectioning the C. elegans for analysis and funds and time to overcome these difficulties were not available in this project. The facilities are now available for preparing biological samples for analysis with the ChIPMA instrument. Some further investment of time and resources in sample preparation should make this a useful tool for chemical imaging applications.

  10. 4-wave mixing for phase-matching free nonlinear optics in quantum cascade structures : LDRD 08-0346 final report.

    SciTech Connect

    Chow, Weng Wah; Wanke, Michael Clement; Allen, Dan G.; Yang, Zhenshan; Waldmueller, Ines

    2010-10-01

    Optical nonlinearities and quantum coherences have the potential to enable efficient, high-temperature generation of coherent THz radiation. This LDRD proposal involves the exploration of the underlying physics using intersubband transitions in a quantum cascade structure. Success in the device physics aspect will give Sandia the state-of-the-art technology for high-temperature THz quantum cascade lasers. These lasers are useful for imaging and spectroscopy in medicine and national defense. Success may have other far-reaching consequences. Results from the in-depth study of coherences, dephasing and dynamics will eventually impact the fields of quantum computing, optical communication and cryptology, especially if we are successful in demonstrating entangled photons or slow light. An even farther reaching development is if we can show that the QC nanostructure, with its discrete atom-like intersubband resonances, can replace the atom in quantum optics experiments. Having such an 'artificial atom' will greatly improve flexibility and preciseness in experiments, thereby enhancing the discovery of new physics. This is because we will no longer be constrained by what natural can provide. Rather, one will be able to tailor transition energies and optical matrix elements to enhance the physics of interest. This report summarizes a 3-year LDRD program at Sandia National Laboratories exploring optical nonlinearities in intersubband devices. Experimental and theoretical investigations were made to develop a fundamental understanding of light-matter interaction in a semiconductor system and to explore how this understanding can be used to develop mid-IR to THz emitters and nonclassical light sources.