Science.gov

Sample records for baseline experiment simulator

  1. GLoBES: General Long Baseline Experiment Simulator

    NASA Astrophysics Data System (ADS)

    Huber, Patrick; Kopp, Joachim; Lindner, Manfred; Rolinec, Mark; Winter, Walter

    2007-09-01

    GLoBES (General Long Baseline Experiment Simulator) is a flexible software package to simulate neutrino oscillation long baseline and reactor experiments. On the one hand, it contains a comprehensive abstract experiment definition language (AEDL), which allows to describe most classes of long baseline experiments at an abstract level. On the other hand, it provides a C-library to process the experiment information in order to obtain oscillation probabilities, rate vectors, and Δχ-values. Currently, GLoBES is available for GNU/Linux. Since the source code is included, the port to other operating systems is in principle possible. GLoBES is an open source code that has previously been described in Computer Physics Communications 167 (2005) 195 and in Ref. [7]). The source code and a comprehensive User Manual for GLoBES v3.0.8 is now available from the CPC Program Library as described in the Program Summary below. The home of GLobES is http://www.mpi-hd.mpg.de/~globes/. Program summaryProgram title: GLoBES version 3.0.8 Catalogue identifier: ADZI_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 145 295 No. of bytes in distributed program, including test data, etc.: 1 811 892 Distribution format: tar.gz Programming language: C Computer: GLoBES builds and installs on 32bit and 64bit Linux systems Operating system: 32bit or 64bit Linux RAM: Typically a few MBs Classification: 11.1, 11.7, 11.10 External routines: GSL—The GNU Scientific Library, www.gnu.org/software/gsl/ Nature of problem: Neutrino oscillations are now established as the leading flavor transition mechanism for neutrinos. In a long history of many experiments, see, e.g., [1], two oscillation frequencies have been identified: The fast atmospheric

  2. Long Baseline Neutrino Experiments

    NASA Astrophysics Data System (ADS)

    Mezzetto, Mauro

    2016-05-01

    Following the discovery of neutrino oscillations by the Super-Kamiokande collaboration, recently awarded with the Nobel Prize, two generations of long baseline experiments had been setup to further study neutrino oscillations. The first generation experiments, K2K in Japan, Minos in the States and Opera in Europe, focused in confirming the Super-Kamiokande result, improving the precision with which oscillation parameters had been measured and demonstrating the ντ appearance process. Second generation experiments, T2K in Japan and very recently NOνA in the States, went further, being optimized to look for genuine three neutrino phenomena like non-zero values of θ13 and first glimpses to leptonic CP violation (LCPV) and neutrino mass ordering (NMO). The discovery of leptonic CP violation will require third generation setups, at the moment two strong proposals are ongoing, Dune in the States and Hyper-Kamiokande in Japan. This review will focus a little more in these future initiatives.

  3. SIMULATION OF A WIDE-BAND LOW-ENERGY NEUTRINO BEAM FOR VERY LONG BASELINE NEUTRINO OSCILLATION EXPERIMENTS.

    SciTech Connect

    BISHAI, M.; HEIM, J.; LEWIS, C.; MARINO, A.D.; VIREN, B.; YUMICEVA, F.

    2006-08-01

    We present simulations of a wide-band low-energy neutrino beam for a future very long baseline neutrino oscillation (VLBNO) program using the proton beam from the Main Injector (MI) proton accelerator at Fermi National Accelerator Laboratory (Fermilab). The target and horn designs previously developed for Brookhaven Laboratory's Alternating Gradient Synchrotron (AGS) VLBNO program are used without modifications. The neutrino flux distributions for various MI proton beam energies and new high-intensity neutrino beam-line designs possible at Fermilab are presented. The beam-line siting and design parameters are chosen to match the requirements of an on-axis beam from Fermilab to one of the two possible sites for the future Deep Underground Science and Engineering Laboratory (DUSEL). A preliminary estimate of the observable event rates and spectra at a detector located in DUSEL for different beam configurations has been performed. Our preliminary conclusions are that a 40-60 GeV 0.5 to 1 MW beam from the Fermilab Main Injector to a DUSEL site has the potential to reach the desired intensity for the next generation of neutrino oscillation experiments. Recent studies indicate that the Fermilab MI can reach a beam power of 0.5 MW at 60 GeV with incremental upgrades to the existing accelerator complex.

  4. Long-Baseline Neutrino Experiments

    DOE PAGES

    Diwan, M. V.; Galymov, V.; Qian, X.; ...

    2016-10-19

    We review long-baseline neutrino experiments in which neutrinos are detected after traversing macroscopic distances. Over such distances neutrinos have been found to oscillate among flavor states. Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixing of the three known flavor states. We will summarize the current best knowledge of neutrino parameters and phenomenology with our focus on the evolution of the experimental technique. We will proceed from the rst evidence produced by astrophysical neutrino sources to the current open questions and the goals of future research

  5. Long-Baseline Neutrino Experiments

    NASA Astrophysics Data System (ADS)

    Diwan, M. V.; Galymov, V.; Qian, X.; Rubbia, A.

    2016-10-01

    We review long-baseline neutrino experiments in which neutrinos are detected after traversing macroscopic distances. Over such distances neutrinos have been found to oscillate among flavor states. Experiments with solar, atmospheric, reactor, and accelerator neutrinos have resulted in a coherent picture of neutrino masses and mixing of the three known flavor states. We summarize the current best knowledge of neutrino parameters and phenomenology, with a focus on the evolution of the experimental technique. We proceed from the first evidence produced by astrophysical neutrino sources to the current open questions and the goals of future research.

  6. Baseline experiments in teleoperator control

    NASA Technical Reports Server (NTRS)

    Hankins, W. W., III; Mixon, R. W.

    1986-01-01

    Studies have been conducted at the NASA Langley Research Center (LaRC) to establish baseline human teleoperator interface data and to assess the influence of some of the interface parameters on human performance in teleoperation. As baseline data, the results will be used to assess future interface improvements resulting from this research in basic teleoperator human factors. In addition, the data have been used to validate LaRC's basic teleoperator hardware setup and to compare initial teleoperator study results. Four subjects controlled a modified industrial manipulator to perform a simple task involving both high and low precision. Two different schemes for controlling the manipulator were studied along with both direct and indirect viewing of the task. Performance of the task was measured as the length of time required to complete the task along with the number of errors made in the process. Analyses of variance were computed to determine the significance of the influences of each of the independent variables. Comparisons were also made between the LaRC data and data taken earlier by Grumman Aerospace Corp. at their facilities.

  7. Long Baseline Neutrino Experiment Sensitivity Studies

    NASA Astrophysics Data System (ADS)

    Norrick, Anne; LBNE Collaboration

    2011-04-01

    The Long Baseline Neutrino Experiment (LBNE) will address the neutrino mass hierarchy, leptonic CP violation, and the value of the mixing angle Theta13 with unprecedented sensitivity. Protons from the Fermilab Main Injector will impinge on a target to create intense fluxes of charged pions and other mesons. The mesons will be guided down a 250 m length of pipe where they will decay creating a muon neutrino beam. The beam will pass through a near detector and travel on to massive detectors located in the Deep Underground Science and Engineering Lab (DUSEL) in Western South Dakota. The near detector at Fermilab will measure the absolute flux of neutrinos before oscillation, and measure signal and background processes in the poorly understood GeV neutrino energy range. To quantify the potential sensitivity of this experiment and the specific needs of the near detector, simulation work has been undertaken. In particular, results of studies using a more sophisticated understanding of various background processes will be presented. Additionally, hardware work for a possible near detector design will be presented.

  8. Systematic errors in long baseline oscillation experiments

    SciTech Connect

    Harris, Deborah A.; /Fermilab

    2006-02-01

    This article gives a brief overview of long baseline neutrino experiments and their goals, and then describes the different kinds of systematic errors that are encountered in these experiments. Particular attention is paid to the uncertainties that come about because of imperfect knowledge of neutrino cross sections and more generally how neutrinos interact in nuclei. Near detectors are planned for most of these experiments, and the extent to which certain uncertainties can be reduced by the presence of near detectors is also discussed.

  9. Simulated Experiments

    ERIC Educational Resources Information Center

    Snadden, R. B.; Runquist, O.

    1975-01-01

    Presents an experiment in which a programmable calculator is employed as a data generating system for simulated laboratory experiments. The example used as an illustration is a simulated conductimetric titration of an aqueous solution of HC1 with an aqueous solution of NaOH. (Author/EB)

  10. CASA Uno GPS orbit and baseline experiments

    NASA Technical Reports Server (NTRS)

    Schutz, B. E.; Ho, C. S.; Abusali, P. A. M.; Tapley, B. D.

    1990-01-01

    CASA Uno data from sites distributed in longitude from Australia to Europe have been used to determine orbits of the GPS satellites. The characteristics of the orbits determined from double difference phase have been evaluated through comparisons of two-week solutions with one-week solutions and by comparisons of predicted and estimated orbits. Evidence of unmodeled effects is demonstrated, particularly associated with the orbit planes that experience solar eclipse. The orbit accuracy has been assessed through the repeatability of unconstrained estimated baseline vectors ranging from 245 km to 5400 km. Both the baseline repeatability and the comparison with independent space geodetic methods give results at the level of 1-2 parts in 100,000,000. In addition, the Mojave/Owens Valley (245 km) and Kokee Park/Ft. Davis (5409 km) estimates agree with VLBI and SLR to better than 1 part in 100,000,000.

  11. CASA Uno GPS orbit and baseline experiments

    NASA Technical Reports Server (NTRS)

    Schutz, B. E.; Ho, C. S.; Abusali, P. A. M.; Tapley, B. D.

    1990-01-01

    CASA Uno data from sites distributed in longitude from Australia to Europe have been used to determine orbits of the GPS satellites. The characteristics of the orbits determined from double difference phase have been evaluated through comparisons of two-week solutions with one-week solutions and by comparisons of predicted and estimated orbits. Evidence of unmodeled effects is demonstrated, particularly associated with the orbit planes that experience solar eclipse. The orbit accuracy has been assessed through the repeatability of unconstrained estimated baseline vectors ranging from 245 km to 5400 km. Both the baseline repeatability and the comparison with independent space geodetic methods give results at the level of 1-2 parts in 100,000,000. In addition, the Mojave/Owens Valley (245 km) and Kokee Park/Ft. Davis (5409 km) estimates agree with VLBI and SLR to better than 1 part in 100,000,000.

  12. Long-baseline neutrino oscillation experiments

    SciTech Connect

    Crane, D.; Goodman, M.

    1994-12-31

    There is no unambiguous definition for long baseline neutrino oscillation experiments. The term is generally used for accelerator neutrino oscillation experiments which are sensitive to {Delta}m{sup 2} < 1.0 eV{sup 2}, and for which the detector is not on the accelerator site. The Snowmass N2L working group met to discuss the issues facing such experiments. The Fermilab Program Advisory Committee adopted several recommendations concerning the Fermilab neutrino program at their Aspen meeting immediately prior to the Snowmass Workshop. This heightened the attention for the proposals to use Fermilab for a long-baseline neutrino experiment at the workshop. The plan for a neutrino oscillation program at Brookhaven was also thoroughly discussed. Opportunities at CERN were considered, particularly the use of detectors at the Gran Sasso laboratory. The idea to build a neutrino beam from KEK towards Superkamiokande was not discussed at the Snowmass meeting, but there has been considerable development of this idea since then. Brookhaven and KEK would use low energy neutrino beams, while FNAL and CERN would plan have medium energy beams. This report will summarize a few topics common to LBL proposals and attempt to give a snapshot of where things stand in this fast developing field.

  13. Effect of computer game playing on baseline laparoscopic simulator skills.

    PubMed

    Halvorsen, Fredrik H; Cvancarova, Milada; Fosse, Erik; Mjåland, Odd

    2013-08-01

    Studies examining the possible association between computer game playing and laparoscopic performance in general have yielded conflicting results and neither has a relationship between computer game playing and baseline performance on laparoscopic simulators been established. The aim of this study was to examine the possible association between previous and present computer game playing and baseline performance on a virtual reality laparoscopic performance in a sample of potential future medical students. The participating students completed a questionnaire covering the weekly amount and type of computer game playing activity during the previous year and 3 years ago. They then performed 2 repetitions of 2 tasks ("gallbladder dissection" and "traverse tube") on a virtual reality laparoscopic simulator. Performance on the simulator were then analyzed for association to their computer game experience. Local high school, Norway. Forty-eight students from 2 high school classes volunteered to participate in the study. No association between prior and present computer game playing and baseline performance was found. The results were similar both for prior and present action game playing and prior and present computer game playing in general. Our results indicate that prior and present computer game playing may not affect baseline performance in a virtual reality simulator.

  14. Design of experiment for earth rotation and baseline parameter determination from very long baseline interferometry

    NASA Technical Reports Server (NTRS)

    Dermanis, A.

    1977-01-01

    The possibility of recovering earth rotation and network geometry (baseline) parameters are emphasized. The numerical simulated experiments performed are set up in an environment where station coordinates vary with respect to inertial space according to a simulated earth rotation model similar to the actual but unknown rotation of the earth. The basic technique of VLBI and its mathematical model are presented. The parametrization of earth rotation chosen is described and the resulting model is linearized. A simple analysis of the geometry of the observations leads to some useful hints on achieving maximum sensitivity of the observations with respect to the parameters considered. The basic philosophy for the simulation of data and their analysis through standard least squares adjustment techniques is presented. A number of characteristic network designs based on present and candidate station locations are chosen. The results of the simulations for each design are presented together with a summary of the conclusions.

  15. The OPERA long baseline neutrino oscillation experiment

    NASA Astrophysics Data System (ADS)

    Wilquet, G.

    2008-05-01

    OPERA is a long baseline neutrino oscillation experiment designed to observe the appearance of vτ in a pure vμ beam in the parameter space indicated by the atmospheric neutrinos oscillation signal. The detector is situated in the underground LNGS laboratory under 3 800 water meter equivalent at a distance of 730 km from CERN where the CNGS neutrino beam to which it is exposed originates. It consists of two identical 0.68 kilotons lead/nuclear emulsion targets, each instrumented with a tracking device and complemented by a muon spectrometer. The concept and the status of the detector are described and the first results obtained with cosmic rays and during two weeks of beam commissioning in 2006 are reported.

  16. Simulation and Baseline Research in Rape Prevention.

    ERIC Educational Resources Information Center

    Brodsky, Stanley L.; Klemmack, Susan H.

    This paper begins by describing an organizational model for the disciplinary study of rape--the University of Alabama's Rape Research Group. It outlines the structure, function, and some techniques of the study group, including the use of simulations and prototypical situations. In one study, verbal responses of rape victims were classified into…

  17. Prospects for long baseline neutrino oscillation experiments

    SciTech Connect

    Goodman, M.

    1991-12-31

    Several recent development have motivated consideration of neutrino experiments located hundreds or thousand of kilometers from an accelerator. The motivations and experimental challenges for such experiments are examined. Three proposals for using the Fermilab Main Injector are compared. The requirements on mass, distance and resolution for an ``ideal`` detector for such an experimental are considered.

  18. Prospects for long baseline neutrino oscillation experiments

    SciTech Connect

    Goodman, M.

    1991-01-01

    Several recent development have motivated consideration of neutrino experiments located hundreds or thousand of kilometers from an accelerator. The motivations and experimental challenges for such experiments are examined. Three proposals for using the Fermilab Main Injector are compared. The requirements on mass, distance and resolution for an ideal'' detector for such an experimental are considered.

  19. Shuttle mission simulator baseline definition report, volume 1

    NASA Technical Reports Server (NTRS)

    Burke, J. F.; Small, D. E.

    1973-01-01

    A baseline definition of the space shuttle mission simulator is presented. The subjects discussed are: (1) physical arrangement of the complete simulator system in the appropriate facility, with a definition of the required facility modifications, (2) functional descriptions of all hardware units, including the operational features, data demands, and facility interfaces, (3) hardware features necessary to integrate the items into a baseline simulator system to include the rationale for selecting the chosen implementation, and (4) operating, maintenance, and configuration updating characteristics of the simulator hardware.

  20. Neutrino Oscillation Parameter Sensitivity in Future Long-Baseline Experiments

    SciTech Connect

    Bass, Matthew

    2014-01-01

    The study of neutrino interactions and propagation has produced evidence for physics beyond the standard model and promises to continue to shed light on rare phenomena. Since the discovery of neutrino oscillations in the late 1990s there have been rapid advances in establishing the three flavor paradigm of neutrino oscillations. The 2012 discovery of a large value for the last unmeasured missing angle has opened the way for future experiments to search for charge-parity symmetry violation in the lepton sector. This thesis presents an analysis of the future sensitivity to neutrino oscillations in the three flavor paradigm for the T2K, NO A, LBNE, and T2HK experiments. The theory of the three flavor paradigm is explained and the methods to use these theoretical predictions to design long baseline neutrino experiments are described. The sensitivity to the oscillation parameters for each experiment is presented with a particular focus on the search for CP violation and the measurement of the neutrino mass hierarchy. The variations of these sensitivities with statistical considerations and experimental design optimizations taken into account are explored. The effects of systematic uncertainties in the neutrino flux, interaction, and detection predictions are also considered by incorporating more advanced simulations inputs from the LBNE experiment.

  1. Shuttle mission simulator baseline definition report, volume 2

    NASA Technical Reports Server (NTRS)

    Dahlberg, A. W.; Small, D. E.

    1973-01-01

    The baseline definition report for the space shuttle mission simulator is presented. The subjects discussed are: (1) the general configurations, (2) motion base crew station, (3) instructor operator station complex, (4) display devices, (5) electromagnetic compatibility, (6) external interface equipment, (7) data conversion equipment, (8) fixed base crew station equipment, and (9) computer complex. Block diagrams of the supporting subsystems are provided.

  2. Is CP violation observable in long baseline neutrino oscillation experiments?

    SciTech Connect

    Tanimoto, M.

    1997-01-01

    We have studied CP violation originating from the phase of the neutrino-mixing matrix in the long baseline neutrino oscillation experiments. The direct measurement of CP violation is the difference of the transition probabilities between CP-conjugate channels. In those experiments, the CP-violating effect is not suppressed if the highest neutrino mass scale is taken to be 1{endash}5 eV, which is appropriate for the cosmological hot dark matter. Assuming the hierarchy for the neutrino masses, the upper bounds of CP violation have been calculated for three cases, in which mixings are constrained by the recent short baseline ones. The calculated upper bounds are larger than 10{sup {minus}2}, which will be observable in the long baseline accelerator experiments. The matter effect, which is not CP invariant, has been also estimated in those experiments. {copyright} {ital 1997} {ital The American Physical Society}

  3. Synthesizing SMOS Zero-Baselines with Aquarius Brightness Temperature Simulator

    NASA Technical Reports Server (NTRS)

    Colliander, A.; Dinnat, E.; Le Vine, D.; Kainulainen, J.

    2012-01-01

    SMOS [1] and Aquarius [2] are ESA and NASA missions, respectively, to make L-band measurements from the Low Earth Orbit. SMOS makes passive measurements whereas Aquarius measures both passive and active. SMOS was launched in November 2009 and Aquarius in June 2011.The scientific objectives of the missions are overlapping: both missions aim at mapping the global Sea Surface Salinity (SSS). Additionally, SMOS mission produces soil moisture product (however, Aquarius data will eventually be used for retrieving soil moisture too). The consistency of the brightness temperature observations made by the two instruments is essential for long-term studies of SSS and soil moisture. For resolving the consistency, the calibration of the instruments is the key. The basis of the SMOS brightness temperature level is the measurements performed with the so-called zero-baselines [3]; SMOS employs an interferometric measurement technique which forms a brightness temperature image from several baselines constructed by combination of multiple receivers in an array; zero-length baseline defines the overall brightness temperature level. The basis of the Aquarius brightness temperature level is resolved from the brightness temperature simulator combined with ancillary data such as antenna patterns and environmental models [4]. Consistency between the SMOS zero-baseline measurements and the simulator output would provide a robust basis for establishing the overall comparability of the missions.

  4. Long-Baseline Neutrino Oscillation Experiments in Europe

    SciTech Connect

    Terranova, F.

    2005-10-12

    Long-baseline experiments will play a crucial role in the precision era of neutrino oscillation physics. In this paper we review the ongoing European programme, which is focused on CNGS, and we discuss the opportunities for new facilities based on the CERN acceleration complex.

  5. Long-baseline neutrino oscillation experiments in North America

    SciTech Connect

    Goodman, M. C.

    2009-03-01

    This contribution to the proceedings of the 2008 NOW Workshop summarizes current and future long-baseline neutrino oscillation experiments in the United States. Together with recent results from MINOS, a future program incorporating NOvA and a long-baseline beam from Fermilab to DUSEL represents one possible scenario for a future U.S. High Energy Physics program with a significant neutrino component. Other futures are also possible. Depending on the value of {theta}{sub 13}, we may find that the future involves serious consideration of intercontinental neutrino beams, with the concomitant additional challenges in planning within an international framework.

  6. Prospects for next generation long-baseline oscillation experiments

    SciTech Connect

    Deborah A Harris

    2003-06-17

    This document describes some of the exciting possibilities for the next steps in the field of long baseline neutrino oscillation measurements. Because the primary goals of these new experiments are so different from those of the current generation, one cannot simply increase the running time or detector mass of the current programs. There are several new strategies which have been discussed for taking the next steps: sometimes the detectors, sometimes the beamlines, and sometimes both are radically different from what is now in place.

  7. Energy reconstruction in the long-baseline neutrino experiment.

    PubMed

    Mosel, U; Lalakulich, O; Gallmeister, K

    2014-04-18

    The Long-Baseline Neutrino Experiment aims at measuring fundamental physical parameters to high precision and exploring physics beyond the standard model. Nuclear targets introduce complications towards that aim. We investigate the uncertainties in the energy reconstruction, based on quasielastic scattering relations, due to nuclear effects. The reconstructed event distributions as a function of energy tend to be smeared out and shifted by several 100 MeV in their oscillatory structure if standard event selection is used. We show that a more restrictive experimental event selection offers the possibility to reach the accuracy needed for a determination of the mass ordering and the CP-violating phase. Quasielastic-based energy reconstruction could thus be a viable alternative to the calorimetric reconstruction also at higher energies.

  8. The MINOS long-baseline experiment at Fermilab

    SciTech Connect

    Ayres, D.S.

    1997-01-02

    The MINOS (Main Injector Neutrino Oscillation Search) long-baseline experiment will search for neutrino oscillations by measuring an intense {nu}{sub {mu}} beam at the end of a 730 km flight path. The 10,000 ton MINOS far detector will utilize magnetized steel plates interleaved with track chambers to reconstruct event topologies and to measure the energies of the muons, hadrons and electromagnetic showers produced by neutrino interactions. The experiment is designed to detect {nu}{sub {mu}} {r_arrow} {nu}{sub {tau}} and {nu}{sub {mu}} {r_arrow} {nu}{sub e} oscillations with {Delta}m{sup 2} {ge} 0.001 eV{sup 2} and sin{sup 2} (2{theta}) {ge} 0.01. Any oscillation signal observed can be verified and studied by several independent tests: a near/far rate comparison, the NC/CC event ratio, the CC and NC event energy spectra, and the identification of electrons and {tau} leptons. The neutrino beam can be operated in both wide-band and narrow-band configurations, allowing the detailed study oscillation phenomena. The experiment is scheduled to begin operation in 2001.

  9. Human Simulated Diving Experiments.

    ERIC Educational Resources Information Center

    Bruce, David S.; Speck, Dexter F.

    1979-01-01

    This report details several simulated divinq experiments on the human. These are suitable for undergraduate or graduate laboratories in human or environmental physiology. The experiment demonstrates that a diving reflex is precipitated by both facial cooling and apnea. (Author/RE)

  10. Scientific Opportunities with the Long-Baseline Neutrino Experiment

    SciTech Connect

    Adams, C.; et al.,

    2013-07-28

    In this document, we describe the wealth of science opportunities and capabilities of LBNE, the Long-Baseline Neutrino Experiment. LBNE has been developed to provide a unique and compelling program for the exploration of key questions at the forefront of particle physics. Chief among the discovery opportunities are observation of CP symmetry violation in neutrino mixing, resolution of the neutrino mass hierarchy, determination of maximal or near-maximal mixing in neutrinos, searches for nucleon decay signatures, and detailed studies of neutrino bursts from galactic supernovae. To fulfill these and other goals as a world-class facility, LBNE is conceived around four central components: (1) a new, intense wide-band neutrino source at Fermilab, (2) a fine-grained `near' neutrino detector just downstream of the source, (3) the Sanford Underground Research Facility (SURF) in Lead, South Dakota at an optimal distance (~1300 km) from the neutrino source, and (4) a massive liquid argon time-projection chamber (LArTPC) deployed there as a 'far' detector. The facilities envisioned are expected to enable many other science opportunities due to the high event rates and excellent detector resolution from beam neutrinos in the near detector and atmospheric neutrinos in the far detector. This is a mature, well developed, world class experiment whose relevance, importance, and probability of unearthing critical and exciting physics has increased with time.

  11. Probing atmospheric mixing and leptonic CP violation in current and future long baseline oscillation experiments

    NASA Astrophysics Data System (ADS)

    Chatterjee, Sabya Sachi; Pasquini, Pedro; Valle, J. W. F.

    2017-08-01

    We perform realistic simulations of the current and future long baseline experiments such as T2K, NOνA, DUNE and T2HK in order to determine their ultimate potential in probing neutrino oscillation parameters. We quantify the potential of these experiments to underpin the octant of the atmospheric angle θ23 as well as the value and sign of the CP phase δCP. We do this both in general, as well as within the predictive framework of a previously proposed [1] benchmark theory of neutrino oscillations which tightly correlates θ23 and δCP.

  12. THE FIRST VERY LONG BASELINE INTERFEROMETRIC SETI EXPERIMENT

    SciTech Connect

    Rampadarath, H.; Morgan, J. S.; Tingay, S. J.; Trott, C. M.

    2012-08-15

    The first Search for Extra-Terrestrial Intelligence (SETI) conducted with very long baseline interferometry (VLBI) is presented. By consideration of the basic principles of interferometry, we show that VLBI is efficient at discriminating between SETI signals and human generated radio frequency interference (RFI). The target for this study was the star Gliese 581, thought to have two planets within its habitable zone. On 2007 June 19, Gliese 581 was observed for 8 hr at 1230-1544 MHz with the Australian Long Baseline Array. The data set was searched for signals appearing on all interferometer baselines above five times the noise limit. A total of 222 potential SETI signals were detected and by using automated data analysis techniques were ruled out as originating from the Gliese 581 system. From our results we place an upper limit of 7 MW Hz{sup -1} on the power output of any isotropic emitter located in the Gliese 581 system within this frequency range. This study shows that VLBI is ideal for targeted SETI including follow-up observations. The techniques presented are equally applicable to next-generation interferometers, such as the long baselines of the Square Kilometre Array.

  13. Reactive flow modeling of small scale detonation failure experiments for a baseline non-ideal explosive

    NASA Astrophysics Data System (ADS)

    Kittell, David E.; Cummock, Nick R.; Son, Steven F.

    2016-08-01

    Small scale characterization experiments using only 1-5 g of a baseline ammonium nitrate plus fuel oil (ANFO) explosive are discussed and simulated using an ignition and growth reactive flow model. There exists a strong need for the small scale characterization of non-ideal explosives in order to adequately survey the wide parameter space in sample composition, density, and microstructure of these materials. However, it is largely unknown in the scientific community whether any useful or meaningful result may be obtained from detonation failure, and whether a minimum sample size or level of confinement exists for the experiments. In this work, it is shown that the parameters of an ignition and growth rate law may be calibrated using the small scale data, which is obtained from a 35 GHz microwave interferometer. Calibration is feasible when the samples are heavily confined and overdriven; this conclusion is supported with detailed simulation output, including pressure and reaction contours inside the ANFO samples. The resulting shock wave velocity is most likely a combined chemical-mechanical response, and simulations of these experiments require an accurate unreacted equation of state (EOS) in addition to the calibrated reaction rate. Other experiments are proposed to gain further insight into the detonation failure data, as well as to help discriminate between the role of the EOS and reaction rate in predicting the measured outcome.

  14. Reactive flow modeling of small scale detonation failure experiments for a baseline non-ideal explosive

    SciTech Connect

    Kittell, David E.; Cummock, Nick R.; Son, Steven F.

    2016-08-14

    Small scale characterization experiments using only 1–5 g of a baseline ammonium nitrate plus fuel oil (ANFO) explosive are discussed and simulated using an ignition and growth reactive flow model. There exists a strong need for the small scale characterization of non-ideal explosives in order to adequately survey the wide parameter space in sample composition, density, and microstructure of these materials. However, it is largely unknown in the scientific community whether any useful or meaningful result may be obtained from detonation failure, and whether a minimum sample size or level of confinement exists for the experiments. In this work, it is shown that the parameters of an ignition and growth rate law may be calibrated using the small scale data, which is obtained from a 35 GHz microwave interferometer. Calibration is feasible when the samples are heavily confined and overdriven; this conclusion is supported with detailed simulation output, including pressure and reaction contours inside the ANFO samples. The resulting shock wave velocity is most likely a combined chemical-mechanical response, and simulations of these experiments require an accurate unreacted equation of state (EOS) in addition to the calibrated reaction rate. Other experiments are proposed to gain further insight into the detonation failure data, as well as to help discriminate between the role of the EOS and reaction rate in predicting the measured outcome.

  15. The Effects of Attrition on Baseline Comparability in Randomized Experiments in Education: A Meta-Analysis

    ERIC Educational Resources Information Center

    Valentine, Jeffrey C.; McHugh, Cathleen M.

    2007-01-01

    Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given…

  16. A recent coincidence experiment of gravitational waves with long baseline

    NASA Astrophysics Data System (ADS)

    Hu, Enke; Guan, Tongren; Yu, Bo; Tang, Mengxi; Chen, Shusen; Zheng, Qingzhang; P, F. Michelson; B, E. Moskowitz; M, S. McAshan; W, M. Fairbank; M, Bassan

    1986-12-01

    The results of coincidence experiment which was carried out in the whole month of April, 1985 by two gravitational wave detectors in stanford and in Guangzhou are presented. It is found that up to sensitivity of h cong 10-16 the number of coincident events did not excess the number expected statistically.

  17. First epoch measurements by Mark III VLBI of the San Andreas Fault experiment baseline

    SciTech Connect

    Ryan, J.W.

    1985-08-01

    The 883-km-long San Andreas Fault Experiment (SAFE) baseline between Quincy in northern California and Monument Peak in southern California spans the San Andreas Fault in a way designed to measure motion between the North American and the Pacific Plates. This baseline and a closely related baseline have been measured with the satellite laser ranging techniques (SLR) for over 10 years. The baseline was measured with the very-long-baseline interferometry (VLBI) technique to confirm or reject the results already obtained from SLR.

  18. SRNL RADIONUCLIDE FIELD LYSIMETER EXPERIMENT: BASELINE CONSTRUCTION AND IMPLEMENTATION

    SciTech Connect

    Roberts, K.; Kaplan, D.; Bagwell, L.; Powell, B.; Almond, P.; Emerson, H.; Hixon, A.; Jablonski, J.; Buchanan, C.; Waterhouse, T.

    2012-10-17

    The purpose of this document is to compile information regarding experimental design, facility design, construction, radionuclide source preparation, and path forward for the ten year Savannah River National Laboratory (SRNL) Radionuclide Field Lysimeter Experiment at the Savannah River Site (SRS). This is a collaborative effort by researchers at SRNL and Clemson University. The scientific objectives of this study are to: Study long-term radionuclide transport under conditions more representative of vadose zone conditions than laboratory experiments; Provide more realistic quantification of radionuclide transport and geochemistry in the vadose zone, providing better information pertinent to radioactive waste storage solutions than presently exists; Reduce uncertainty and improve justification for geochemical models such as those used in performance assessments and composite analyses.

  19. REPORT OF THE US LONG BASELINE NEUTRINO EXPERIMENT STUDY.

    SciTech Connect

    BARGER,V.; FINLEY, D.; LAUGHTON, C.; PORDES, S.; MARCHIONNI, A.; RAMEIKA, R.; SAOULIDOU, N.; ZWASKA, R.; BISHAI, M.; DIWAN, M.; DIERCKXSENS, M.; KIRK, H.; KAHN, S.; SIMOS, N.; MARCIANO, W.; PARSA, Z.; VIREN, B.; ET AL.

    2007-01-01

    This report provides the results of an extensive and important study of the potential for a U.S. scientific program that will extend our knowledge of neutrino oscillations well beyond what can be anticipated from ongoing and planned experiments worldwide. The program examined here has the potential to provide the U.S. particle physics community with world leading experimental capability in this intensely interesting and active field of fundamental research. Furthermore, this capability is not likely to be challenged anywhere else in the world for at least two decades into the future. The present study was initially commissioned in April 2006 by top research officers of Brookhaven National Laboratory and Fermilab and, as the study evolved, it also provides responses to questions formulated and addressed to the study group by the Neutrino Scientific Advisory Committee (NuSAG) of the U.S. DOE and NSF. The participants in the study, its Charge and history, plus the study results and conclusions are provided in this report and its appendices. A summary of the conclusions is provided in the Executive Summary.

  20. The Science and Strategy for Phasing of the Long-Baseline Neutrino Experiment

    SciTech Connect

    Diwan, Milind V.

    2012-05-22

    This note is about the principles behind a phased plan for realizing a Long-Baseline Neutrino Experiment(LBNE) in the U.S.. The most important issue that must be resolved is the direction of the first phase of the experiment. Based on both scientific and programmatic considerations, the U.S. should pursue the best option for accelerator neutrino physics, which is the longer baseline towards Homestake with an optimizedbroadband intense beam.

  1. Hydrodynamic instability experiments and simulations

    SciTech Connect

    Dimonte, G.; Schneider, M.; Frerking, C.E.

    1995-07-01

    Richtmyer-Meshkov experiments are conducted on the Nova laser with strong radiatively driven shocks (Mach > 20) in planar, two-fluid targets with Atwood number A < 0. Single mode interfacial perturbations are used to test linear theory and 3D random perturbations are used to study turbulent mix. Rayleigh-Taylor experiments are conducted on a new facility called the Linear Electric Motor (LEM) in which macroscopic fluids are accelerated electromagnetically with arbitrary acceleration profiles. The initial experiments are described. Hydrodynamic simulations in 2D are in reasonable agreement with the experiments, but these studies show that simulations in 3D with good radiation transport and equation of state are needed.

  2. Capabilities of long-baseline experiments in the presence of a sterile neutrino

    DOE PAGES

    Dutta, Debajyoti; Gandhi, Raj; Kayser, Boris; ...

    2016-11-21

    Assuming that there is a sterile neutrino, we ask what then is the ability of long-baseline experiments to i) establish that neutrino oscillation violates CP, ii) determine the three-neutrino mass ordering, and iii) determine which CP-violating phase or phases are the cause of any CP violation that may be observed. We find that the ability to establish CP violation and to determine the mass ordering could be very substantial. However, the effects of the sterile neutrino could be quite large, and it might prove very difficult to determine which phase is responsible for an observed CP violation. We explain whymore » a sterile neutrino changes the long-baseline sensitivities to CP violation and to the mass ordering in the ways that it does. We note that long-baseline experiments can probe the presence of sterile neutrinos in a way that is different from, and complementary to, the probes of short-baseline experiments. As a result, we explore the question of how large sterile-active mixing angles need to be before long-baseline experiments can detect their effects, or how small they need to be before the interpretation of these experiments can safely disregard the possible existence of sterile neutrinos.« less

  3. Capabilities of long-baseline experiments in the presence of a sterile neutrino

    SciTech Connect

    Dutta, Debajyoti; Gandhi, Raj; Kayser, Boris; Masud, Mehedi; Prakash, Suprabh

    2016-11-21

    Assuming that there is a sterile neutrino, we ask what then is the ability of long-baseline experiments to i) establish that neutrino oscillation violates CP, ii) determine the three-neutrino mass ordering, and iii) determine which CP-violating phase or phases are the cause of any CP violation that may be observed. We find that the ability to establish CP violation and to determine the mass ordering could be very substantial. However, the effects of the sterile neutrino could be quite large, and it might prove very difficult to determine which phase is responsible for an observed CP violation. We explain why a sterile neutrino changes the long-baseline sensitivities to CP violation and to the mass ordering in the ways that it does. We note that long-baseline experiments can probe the presence of sterile neutrinos in a way that is different from, and complementary to, the probes of short-baseline experiments. As a result, we explore the question of how large sterile-active mixing angles need to be before long-baseline experiments can detect their effects, or how small they need to be before the interpretation of these experiments can safely disregard the possible existence of sterile neutrinos.

  4. Effects of baseline conditions on the simulated hydrologic response to projected climate change

    USGS Publications Warehouse

    Koczot, Kathryn M.; Markstrom, Steven L.; Hay, Lauren E.

    2011-01-01

    Changes in temperature and precipitation projected from five general circulation models, using one late-twentieth-century and three twenty-first-century emission scenarios, were downscaled to three different baseline conditions. Baseline conditions are periods of measured temperature and precipitation data selected to represent twentieth-century climate. The hydrologic effects of the climate projections are evaluated using the Precipitation-Runoff Modeling System (PRMS), which is a watershed hydrology simulation model. The Almanor Catchment in the North Fork of the Feather River basin, California, is used as a case study. Differences and similarities between PRMS simulations of hydrologic components (i.e., snowpack formation and melt, evapotranspiration, and streamflow) are examined, and results indicate that the selection of a specific time period used for baseline conditions has a substantial effect on some, but not all, hydrologic variables. This effect seems to be amplified in hydrologic variables, which accumulate over time, such as soil-moisture content. Results also indicate that uncertainty related to the selection of baseline conditions should be evaluated using a range of different baseline conditions. This is particularly important for studies in basins with highly variable climate, such as the Almanor Catchment.

  5. TARGET AND HORN COOLING FOR THE VERY LONG BASELINE NEUTRINO EXPERIMENT.

    SciTech Connect

    BELLAVIA, S.; KAHN, S.; KIRK, H.; LUDEWIG, H.; RAPARIA, D.; SIMOS, N.

    2005-05-16

    Thermodynamic studies have been performed for the beam target and focusing horn system to be used in a very long baseline neutrino oscillation experiment [1]. A 2mm rms beam spot with power deposition of over 18 KW presents challenging material and engineering solutions to this project. Given that the amount of heat transferred by radiation alone from the target to the horn is quite small, the primary mechanism is heat removal by forced convection in the annular space between the target and the horn. The key elements are the operating temperature of the target, the temperature of the cooling fluid and the heat generation rate in the volume of the target that needs to be removed. These working parameters establish the mass flow rate and velocity of the coolant necessary to remove the generated heat. Several cooling options were explored using a carbon-carbon target and aluminum horn. Detailed analysis, trade studies and simulations were performed for cooling the horn and target with gaseous helium as well as water.

  6. Baseline geoenvironmental experiments for in-situ soil transformation by plasma torch

    SciTech Connect

    Beaver, J.R.; Mayne, P.W.

    1995-12-31

    The advent of the nontransferred plasma arc torch has implicated a range of in-situ geoenvironmental applications that can revolutionize methods of ground modification and field remediation of contaminated sites. With reverse polarity nontransferred arc type plasma torches, temperatures of 4,000 C to 7,000 C can be directed at specific targets of contaminated soil or waste. At these extreme temperatures, all organic materials within the soil undergo pyrolysis, while the bulk composition is transformed into a magma that subsequently cools to form a vitrified mass resembling volcanic obsidian or a dense partially crystalline material resembling microcrystalline igneous rock. Simulations of in-situ transformation of soil have been conducted using both 100-kW and 240-kW torches to alter clay, silty sand, and sand in chamber tests. Although these materials are primarily composed of silica and alumina oxides having melting temperatures of 1,100 C to 1,600 C, the formation of a spheroidal magma core occurred within the first five minutes of exposure to the plasma flame. Experiments were conducted to quantify the improved engineering properties that occur after transformation and to demonstrate the relative effects of power level, water content, and soil type on the size and strength of the altered material. The ongoing research also serves as a baseline study for further experimentation that will focus on the in-situ remediation of soils with varied contaminants.

  7. Statistical validation of predictive TRANSP simulations of baseline discharges in preparation for extrapolation to JET D-T

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Tae; Romanelli, M.; Yuan, X.; Kaye, S.; Sips, A. C. C.; Frassinetti, L.; Buchanan, J.; Contributors, JET

    2017-06-01

    This paper presents for the first time a statistical validation of predictive TRANSP simulations of plasma temperature using two transport models, GLF23 and TGLF, over a database of 80 baseline H-mode discharges in JET-ILW. While the accuracy of the predicted T e with TRANSP-GLF23 is affected by plasma collisionality, the dependency of predictions on collisionality is less significant when using TRANSP-TGLF, indicating that the latter model has a broader applicability across plasma regimes. TRANSP-TGLF also shows a good matching of predicted T i with experimental measurements allowing for a more accurate prediction of the neutron yields. The impact of input data and assumptions prescribed in the simulations are also investigated in this paper. The statistical validation and the assessment of uncertainty level in predictive TRANSP simulations for JET-ILW-DD will constitute the basis for the extrapolation to JET-ILW-DT experiments.

  8. GEANT4 Hadron Monitor Simulation Studies for the Long-Baseline Neutrino Facility

    NASA Astrophysics Data System (ADS)

    Watson, Timothy; Bashyal, Amit; Yu, Jaehoon; Long Baseline Neutrino Facility Collaboration

    2015-04-01

    The hadron monitor to be incorporated into the beamline of the Long-Baseline Neutrino Facility at Fermilab is a crucial tool for alignment purposes as well as the correct functionality of the beam. Designing such a hadron monitor requires careful consideration of the challenges presented. The high-radiation environment from the considerably higher proton beam power expected for LBNF at the monitor location coupled with the need for relatively higher spatial resolution from the monitor will require an innovative new detector technology and design. To this end, computer simulations are a useful tool. Presented here are the results of hadron monitor design studies simulated using GEANT4.

  9. The effect of tracking network configuration on GPS baseline estimates for the CASA Uno experiment

    NASA Technical Reports Server (NTRS)

    Wolf, S. Kornreich; Dixon, T. H.; Freymueller, J. T.

    1990-01-01

    The effect of the tracking network on long (greater than 100 km) GPS baseline estimates was estimated using various subsets of the global tracking network initiated by the first Central and South America (CASA Uno) experiment. It was found that best results could be obtained with a global tacking network consisting of three U.S. stations, two sites in the southwestern Pacific, and two sites in Europe. In comparison with smaller subsets, this global network improved the baseline repeatability, the resolution of carrier phase cycle ambiguities, and formal errors of the orbit estimates.

  10. The effect of tracking network configuration on GPS baseline estimates for the CASA Uno experiment

    NASA Technical Reports Server (NTRS)

    Wolf, S. Kornreich; Dixon, T. H.; Freymueller, J. T.

    1990-01-01

    The effect of the tracking network on long (greater than 100 km) GPS baseline estimates was estimated using various subsets of the global tracking network initiated by the first Central and South America (CASA Uno) experiment. It was found that best results could be obtained with a global tacking network consisting of three U.S. stations, two sites in the southwestern Pacific, and two sites in Europe. In comparison with smaller subsets, this global network improved the baseline repeatability, the resolution of carrier phase cycle ambiguities, and formal errors of the orbit estimates.

  11. Short-baseline electron neutrino oscillation length after the Troitsk experiment

    NASA Astrophysics Data System (ADS)

    Giunti, C.; Laveder, M.; Li, Y. F.; Long, H. W.

    2013-01-01

    We discuss the implications for short-baseline electron neutrino disappearance in the 3+1 mixing scheme of the recent Troitsk bounds on the mixing of a neutrino with mass between 2 and 100 eV. Considering the Troitsk data in combination with the results of short-baseline νe and ν¯e disappearance experiments, which include the reactor and Gallium anomalies, we derive a 2σ allowed range for the effective neutrino squared-mass difference between 0.85 and 43eV2. The upper bound implies that it is likely that oscillations in distance and/or energy can be observed in radioactive source experiments. It is also favorable for the ICARUS@CERN experiment, in which it is likely that oscillations are not washed out in the near detector. We discuss also the implications for neutrinoless double-β decay.

  12. Octant of θ23 at long baseline neutrino experiments in the light of nonunitary leptonic mixing

    NASA Astrophysics Data System (ADS)

    Dutta, Debajyoti; Ghoshal, Pomita; Sehrawat, Sandeep K.

    2017-05-01

    The octant of the atmospheric mixing angle θ23 is still undetermined by neutrino oscillation experiments. Long-baseline experiments like NO ν A , T2K, and DUNE offer good prospects for determining the octant of θ23. However, their capability to do so may be compromised by the possible presence of nonunitarity in the leptonic mixing matrix. In this paper, we study in detail the octant degeneracy with and without nonunitarity at the level of oscillation probabilities and events for these experiments. We also analyze their octant sensitivity and discovery reach and show that they are hampered in the presence of nonunitarity.

  13. Optimizing the θ 23 octant search in long baseline neutrino experiments

    NASA Astrophysics Data System (ADS)

    Das, C. R.; Maalampi, J.; Pulido, J.; Vihonen, S.

    2017-09-01

    Determination of the θ 23 octant will be an important goal for the next generation of neutrino oscillation experiments, as it will show whether the true value of θ 23 lies in the high octant, θ 23 > 45°, or in the low octant, θ 23 < 45°. In this work we investigate the prospects of studying the θ 23 octant in future long baseline neutrino experiments. Using the GLoBES software, we study the sensitivity to θ 23 octant in terms of baseline length and beam sharing and use the LBNO setup as our benchmark. We also show the interference on the octant determination that arises from the unconstrained CP violation angle δ CP. In our results, we show the impact of matter effects on the octant determination potential and establish a connection between the beam sharing and mass hierarchy.

  14. CP violation and matter effect in long baseline neutrino oscillation experiments

    SciTech Connect

    Arafune, J.; Koike, M.; Sato, J.

    1997-09-01

    We show simple methods of how to separate pure CP-violating effects from matter effects in long baseline neutrino oscillation experiments with three generations of neutrinos. We give compact formulas for neutrino oscillation probabilities assuming one of the three neutrino masses (presumably {nu}{sub {tau}} mass) to be much larger than the other masses and the effective mass due to the matter effect. Two methods are shown. One is to observe envelopes of the curves of oscillation probabilities as functions of neutrino energy; a merit of this method is that only a single detector is enough to determine the presence of CP violation. The other is to compare experiments with at least two different baseline lengths; this has the merit that it needs only a narrow energy range of oscillation data. {copyright} {ital 1997} {ital The American Physical Society}

  15. Turbulent mix experiments and simulations

    SciTech Connect

    Dimonte, G.; Schneider, M.; Frerking, C.E.

    1995-08-01

    Hydrodynamic instabilities produce material mixing that can significantly degrade weapons performance. We investigate the Richtmyer-Meshkov (RM) and Rayleigh-Taylor (RT) instabilities in the turbulent regime in two experimental venues. RM experiments are conducted on the Nova laser with strong radiatively driven shocks (Mach > 20) in planar, two fluid targets. Interfacial perturbations are imposed with single sinusoidal modes to test linear theory and with three dimensional (3D) random modes to produce turbulent mix. RT experiments are conducted on a new facility, the Linear Electric Motor (LEM), in which macroscopic fluids are accelerated with arbitrary temporal profiles. This allows detailed diagnosis of the turbulence over a wide range of conditions. The Nova experiments study the high compression regime whereas the LEM experiments are incompressible. The results are compared to hydrodynamic simulations with the arbitrary Lagrangian-Eulerian code (CALE). The goal is to develop and test engineering models of mix.

  16. Studies of earth simulation experiments

    NASA Technical Reports Server (NTRS)

    Hart, J. E.

    1976-01-01

    The low gravity environment of earth orbit offers the potential for performing experiments involving baroclinic Geophysical Fluid Dynamics (GFD) on spherical surfaces. These experiments in turn have the potential for providing deeper understanding of large scale planetary and solar circulations. However, to perform these experiments, one requires an experimental technique whereby a radially directed body force can be generated to simulate a radial gravitational force field. One viable technique is the use of dielectric fluids with temperature dependent dielectric permittivity in a radially directed electric field. Application of the Boussinesq approximation to the equations of motion for this system and restrictions on the size of certain electrodynamic terms in the energy equations yields a set of equations which are analogous to the equations of motions of geophysical systems like the earth's atmosphere on term by term basis. The theoretical design of GFD experiments for performance in earth orbit are described along with results of preliminary tests of a prototype.

  17. FOCUSING HORN SYSTEM FOR THE BNL VERY LONG BASELINE NEUTRINO OSCILLATION EXPERIMENT.

    SciTech Connect

    KAHN,S.A.CARROLL,A.DIWAN,M.V.GALLARDO,J.C.KIRK,H.SCARLETT,C.SIMOS,N.VIREN,B.ZHANG,W.

    2003-05-12

    This paper describes the focusing horn system for the proposed very long baseline neutrino oscillation experiment using a neutrino beam from BNL to an underground facility such as the Homestake Mine in South Dakota. The proposed experiment uses a 1 MW upgraded AGS. In order to achieve this performance the AGS will operate with a cycle time of 2.5 Hz and 8.9 x 10{sup 13} protons on target at 28 GeV. This paper discusses the design criteria of a horn system necessary to handle this intense beam and the optical geometry to achieve the desired flux distribution at the detector.

  18. The first results of K2K long-baseline neutrino oscillation experiment

    NASA Astrophysics Data System (ADS)

    Ishida, Taku; K2K Collaboration

    2000-12-01

    The first results of the K2K (KEK to Kamioka) long-baseline neutrino oscillation experiment are presented in this talk. In 1999 7.2×1018 protons on target were delivered to the experiment. During this period of running there were 3 events fully contained in the Super-Kamiokande inner detector fiducial area which occurred during the beam spill timing window. In the case of no oscillations the expected number of events during this period was 12.3-1.9+1.7. The near detectors located at KEK also have begun detailed measurements of neutrino interactions in water at around 1 GeV.

  19. PROSPECT: A Short-baseline Reactor Precision Spectrum and Oscillation Experiment

    NASA Astrophysics Data System (ADS)

    Langford, Thomas; Prospect Collaboration

    2015-10-01

    PROSPECT is a phased experiment consisting of segmented Li-loaded liquid scintillator antineutrino detectors designed to probe short-baseline neutrino oscillations and precisely measure the reactor antineutrino spectrum. The experiment will be located at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Lab. The first phase is a movable 2.5 tonne detector located 7-9 m from the compact, highly enriched uranium (HEU) core. Over the past two years, PROSPECT has deployed multiple prototype detectors at HFIR to understand the local background environment and demonstrate active and passive background rejection. Measuring the neutrino spectrum from 235U will give insight to the recent spectral discrepancies and provide an important benchmark for future reactor experiments. As a high statistics experiment, PROSPECT will probe the sterile neutrino best-fit region within one year of operation at HFIR.

  20. Accurate GPS orientation of a long baseline for Neutrino Oscillation Experiments at Fermilab

    NASA Astrophysics Data System (ADS)

    Soler, Tomás; Foote, Richard H.; Hoyle, Dixon; Bocean, Virgil

    2000-12-01

    Recent research in elementary particle physics is concentrating a great amount of effort on neutrino oscillation experiments. These studies require the accurate pointing of neutrino beams between two distant points. The Fermi National Accelerator Laboratory (Fermilab) intends to build a new particle beamline to direct a beam of muon neutrinos from its Main Injector toward a far-off (735 km away) underground detector capable of searching for non-zero neutrino mass by looking for neutrino oscillations. This paper describes the GPS work carried out to accurately position the reference ground marks at the two sites from which the spatial orientation of the baseline can be accurately determined. The effect of plate rotations on the absolute orientation of the baseline was also investigated.

  1. Measuring the mass of a sterile neutrino with a very short baseline reactor experiment

    NASA Astrophysics Data System (ADS)

    Latimer, D. C.; Escamilla, J.; Ernst, D. J.

    2007-04-01

    An analysis of the world's neutrino oscillation data, including sterile neutrinos, [M. Sorel, C. M. Conrad, and M. H. Shaevitz, Phys. Rev. D 70, 073004 (2004)] found a peak in the allowed region at a mass-squared difference Δm2≅0.9eV2. We trace its origin to harmonic oscillations in the electron survival probability Pee as a function of L/E, the ratio of baseline to neutrino energy, as measured in the near detector of the Bugey experiment. We find a second occurrence for Δm2≅1.9eV2. We point out that the phenomenon of harmonic oscillations of Pee as a function of L/E, as seen in the Bugey experiment, can be used to measure the mass-squared difference associated with a sterile neutrino in the range from a fraction of an eV2 to several eV2 (compatible with that indicated by the LSND experiment), as well as measure the amount of electron-sterile neutrino mixing. We observe that the experiment is independent, to lowest order, of the size of the reactor and suggest the possibility of a small reactor with a detector sitting at a very short baseline.

  2. Measuring the mass of a sterile neutrino with a very short baseline reactor experiment

    SciTech Connect

    Latimer, D. C.; Escamilla, J.; Ernst, D. J.

    2007-04-15

    An analysis of the world's neutrino oscillation data, including sterile neutrinos, [M. Sorel, C. M. Conrad, and M. H. Shaevitz, Phys. Rev. D 70, 073004 (2004)] found a peak in the allowed region at a mass-squared difference {delta}m{sup 2} congruent with 0.9 eV{sup 2}. We trace its origin to harmonic oscillations in the electron survival probability P{sub ee} as a function of L/E, the ratio of baseline to neutrino energy, as measured in the near detector of the Bugey experiment. We find a second occurrence for {delta}m{sup 2} congruent with 1.9 eV{sup 2}. We point out that the phenomenon of harmonic oscillations of P{sub ee} as a function of L/E, as seen in the Bugey experiment, can be used to measure the mass-squared difference associated with a sterile neutrino in the range from a fraction of an eV{sup 2} to several eV{sup 2} (compatible with that indicated by the LSND experiment), as well as measure the amount of electron-sterile neutrino mixing. We observe that the experiment is independent, to lowest order, of the size of the reactor and suggest the possibility of a small reactor with a detector sitting at a very short baseline.

  3. Validation of a fault-tolerant multiprocessor: Baseline experiments and workload implementation

    NASA Technical Reports Server (NTRS)

    Feather, Frank; Siewiorek, Daniel; Segall, Zary

    1985-01-01

    In the future, aircraft must employ highly reliable multiprocessors in order to achieve flight safety. Such computers must be experimentally validated before they are deployed. This project outlines a methodology for validating reliable multiprocessors. The methodology begins with baseline experiments, which tests a single phenomenon. As experiments progress, tools for performance testing are developed. The methodology is used, in part, on the Fault Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB facility. Experiments are designed to evaluate the fault-free performance of the system. Presented are the results of interrupt baseline experiments performed on FTMP. Interrupt causing exception conditions were tested, and several were found to have unimplemented interrupt handling software while one had an unimplemented interrupt vector. A synthetic workload model for realtime multiprocessors is then developed as an application level performance analysis tool. Details of the workload implementation and calibration are presented. Both the experimental methodology and the synthetic workload model are general enough to be applicable to reliable multiprocessors beside FTMP.

  4. A large liquid scintillator detector for a long baseline neutrino oscillation experiment

    NASA Astrophysics Data System (ADS)

    Border, P.; Cushman, P.; Heller, K.; Maxam, D.; Nelson, J. K.; Ruddick, K.; Rusack, R.; Schwienhorst, R.; Berg, T.; Chase, T.; Hansen, M.; Bower, C.; Hatcher, R.; Heinz, R.; Miller, L.; Mufson, S.

    2001-05-01

    We present the concept and design of a liquid scintillator detector for a long-baseline neutrino oscillation experiment. Neutrinos interact in 2.5 cm thick steel plates alternating with 2.0 cm thick planes of liquid scintillator. The scintillator is contained in multicell PVC extrusions containing individual 2 cm×3 cm cells up to 8 m long. Readout of the scintillation light is via wavelength-shifting fibers which transport light to pixellated photodetectors at one end of the cells.

  5. Investigation of neutrino oscillations in the T2k long-baseline accelerator experiment

    SciTech Connect

    Izmaylov, A. O. Yershov, N. V.; Kudenko, Yu. G.; Matveev, V. A.; Mineev, O. V.; Musienko, Yu. V.; Khabibulliun, M. M.; Khotjantsev, A. N.; Shaykhiev, A. T.

    2012-02-15

    High-sensitivity searches for transitions of muon neutrinos to electron neutrinos are the main task of the T2K (Tokai-to-Kamioka) second-generation long-baseline accelerator neutrino experiment. The present article is devoted to describing basic principles of T2K, surveying experimental apparatuses that it includes, and considering in detail the muon-range detector (SMRD) designed and manufactured by a group of physicists from the Institute of Nuclear Research (Russian Academy of Sciences, Moscow). The results of the first measurements with a neutrino beam are presented, and plans for the near future are discussed.

  6. Simulation of the DRIFT Experiment

    NASA Astrophysics Data System (ADS)

    Hyatt, Matt; Ayad, Rachid; Hanson-Hart, Zach; Katz-Hyman, Moshe; Posner, Aaron; Martoff, C. J.

    2003-04-01

    The DRIFT Experiment [1] is an underground search for WIMP Dark Matter using a novel detector invented for this purpose: the Negative Ion TPC (NITPC). To aid in interpreting the results, a simulation code system has been developed. The system uses the CERNLIB program GEANT [2] and the NRC package EGS4 [3] to simulate particle interactions in the detector. These are linked directly to the CERNLIB program GARFIELD, which simulates signal production in the NITPC. Finally the GARFIELD output is converted into the format of the DRIFT DAQ for presentation to the analysis code. The physics and software issues dealt with in this development will be discussed. [1] Low Pressure Negative Ion TPC for Dark Matter Search. D. P. Snowden-Ifft, C. J. Martoff, J. M. Burwell, Phys Rev. D. Rapid Comm. 61, 101301 (2000) [2] GEANT Manual, CERN Program Library Long Writeup W5013, Copyright CERN, Geneva, 1993 . [3] EGS4, National Research Council, Canada. Note PIRS-701. http://www.irs.inms.nrc.ca/inms/irs/EGS4/get_egs4.html . [4] GARFIELD Manual, version 7.04, CERN Program Library Long Writeup W5050, Copyright CERN, Geneva, 2001 .

  7. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine

    PubMed Central

    Roni Sahroni, Taufik

    2015-01-01

    This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure's response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed. PMID:26550605

  8. Dispersion analysis for baseline reference mission 1. [flight simulation and trajectory analysis for space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Kuhn, A. E.

    1975-01-01

    A dispersion analysis considering 3 sigma uncertainties (or perturbations) in platform, vehicle, and environmental parameters was performed for the baseline reference mission (BRM) 1 of the space shuttle orbiter. The dispersion analysis is based on the nominal trajectory for the BRM 1. State vector and performance dispersions (or variations) which result from the indicated 3 sigma uncertainties were studied. The dispersions were determined at major mission events and fixed times from lift-off (time slices) and the results will be used to evaluate the capability of the vehicle to perform the mission within a 3 sigma level of confidence and to determine flight performance reserves. A computer program is given that was used for dynamic flight simulations of the space shuttle orbiter.

  9. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine.

    PubMed

    Roni Sahroni, Taufik

    2015-01-01

    This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure's response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed.

  10. Comet Simulation Experiments at JPL

    NASA Astrophysics Data System (ADS)

    Green, J. R.; Bruesch, L. S.; Oakes, R.; Pinkham, B.; Folsom, C. L.

    1999-12-01

    recorded on video tape. A mechanical penetrator-scratcher measures penetrability and disturbs the surface for assessment of surface changes. At the end of the experiment, the sample is removed and core samples are taken for tests of compression strength, penetrability, porosity, density, and thin section analysis. Methods allowing detailed microscopic examination of the samples are under development. A freezing microtome for cutting thin sections of the sample and a freezing stage on a microscope are to be used for examination of the pore and grain structure of the icy mixtures. With all elements in place for the laboratory simulation of cometary materials, we are now performing our first experiments and plan to report our preliminary results.

  11. Baseline monitoring using aircraft laser ranging. [spaceborne laser simulation and aircraft laser tracking

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Hoge, F. E.; Martin, C. F.

    1982-01-01

    The use of aircraft laser ranging for the determination of baselines between ground based retroreflectors was investigated via simulations and with tests at Wallops Flight Center using the Airborne Oceanographic Lidar (AOL) on the Wallops C-54 aircraft ranging to a reflector array deployed around one of the Wallops runways. The aircraft altitude and reflector spacing were chosen on the basis of scaled down modeling of spacecraft tracking from 1000 km of reflectors separated by some 52 km, or of high altitude (10 km) aircraft tracking of reflectors separated by some 500 m. Aircraft altitudes flown for different passes across the runway reflector array varied from 800 m to 1350 m, with 32 reflectors deployed over an approximtely 300 m x 500 m ground pattern. The AOL transmitted 400 pulses/sec with a scan rate of 5/sec in a near circular pattern, so that the majority of the pulses were reflected by the runway surface or its environs rather than by retroreflectors. The return pulse characteristics clearly showed the high reflectivity of portions of the runway, with several returns indistinguishable in amplitude from reflector returns. For each pass across the reflector field, typically six to ten reflector hits were identified, consistent with that predicted by simulations and the observed transmitted elliptical pulse size.

  12. Space Station Simulation Computer System (SCS) study for NASA/MSFC. Volume 2: Baseline architecture report

    NASA Technical Reports Server (NTRS)

    1990-01-01

    NASA's Space Station Freedom Program (SSFP) planning efforts have identified a need for a payload training simulator system to serve as both a training facility and as a demonstrator to validate operational concepts. The envisioned MSFC Payload Training Complex (PTC) required to meet this need will train the Space Station payload scientists, station scientists, and ground controllers to operate the wide variety of experiments that will be onboard the Space Station Freedom. The Simulation Computer System (SCS) is the computer hardware, software, and workstations that will support the Payload Training Complex at MSFC. The purpose of this SCS Study is to investigate issues related to the SCS, alternative requirements, simulator approaches, and state-of-the-art technologies to develop candidate concepts and designs.

  13. Space Station Simulation Computer System (SCS) study for NASA/MSFC. Volume 1: Baseline architecture report

    NASA Technical Reports Server (NTRS)

    1990-01-01

    NASA's Space Station Freedom Program (SSFP) planning efforts have identified a need for a payload training simulator system to serve as both a training facility and as a demonstrator to validate operational concepts. The envisioned MSFC Payload Training Complex (PTC) required to meet this need will train the Space Station payload scientists, station scientists, and ground controllers to operate the wide variety of experiments that will be onboard the Space Station Freedom. The Simulation Computer System (SCS) is made up of the computer hardware, software, and workstations that will support the Payload Training Complex at MSFC. The purpose of this SCS Study is to investigate issues related to the SCS, alternative requirements, simulator approaches, and state-of-the-art technologies to develop candidate concepts and designs.

  14. Alcator C-Mod Experiments in Support of the ITER Baseline 15 MA Scenario

    SciTech Connect

    C Kessel, et al

    2013-05-07

    Experiments on Alcator C-Mod have addressed several issues for the ITER 15 MA baseline scenario from 2009-2012. Rampup studies show ICRF can save significant V-s, and that an H-mode in the ramp can be utilized to save 50% more. ICRF modifications to li(1) are minimal, although the Te profile is peaked relative to ohmic in the plasma center, and alter sawtooth onset times. Rampdown studies show H-modes can be routinely sustained, avoiding an OH coil over-current associated with the H-L transition, that fast rampdowns are preferred, the density drops with Ip, and that the H-L transition occurs at Ploss/Pthr,LH ~ 1.0-1.3 at n/nGr ~ 0.85. Flattop plasmas targeting ITER baseline parameters have been sustained for 20 τE or 8-13 τCR, but only reach H98 ~ 0.6 at n/nGr = 0.85, rising to 0.9 at n/nGr = 0.65.

  15. Large-θ 13 perturbation theory of neutrino oscillation for long-baseline experiments

    NASA Astrophysics Data System (ADS)

    Asano, Katsuhiro; Minakata, Hisakazu

    2011-06-01

    The Cervera et al. formula, the best known approximate formula of neutrino oscillation probability for long-baseline experiments, can be regarded as a second-order perturbative formula with small expansion parameter ɛ ≡ ∆ m {21/2} ∆ m {31/2} ≃ 0 .03 under the 21assumption s 13 ≃ ɛ. If θ 13 is large, as suggested by a candidate ν e event at T2K as well as the recent global analyses, higher order corrections of s 13 to the formula would be needed for better accuracy. We compute the corrections systematically by formulating a perturbative framework by taking θ 13 as {s_{13}} ˜ sqrt { in } ˜eq 0.18 , which guarantees its validity in a wide range of θ 13 below the Chooz limit. We show on general ground that the correction terms must be of order ɛ2. Yet, they nicely fill the mismatch between the approximate and the exact formulas at low energies and relatively long baselines. General theorems are derived which serve for better understanding of δ-dependence of the oscillation probability. Some interesting implications of the large θ 13 hypothesis are discussed.

  16. Neutrino Interactions with Nucleons and Nuclei: Importance for Long-Baseline Experiments

    NASA Astrophysics Data System (ADS)

    Mosel, Ulrich

    2016-10-01

    This article reviews our present knowledge of neutrino interactions with nucleons and discusses the interactions with nuclei, the target material of all presently running and planned long-baseline experiments. I emphasize descriptions of semi-inclusive reactions and full descriptions of the final state; the latter are needed to reconstruct the incoming neutrino energy from final-state observations. I then discuss Monte Carlo generator and more advanced transport-theoretical approaches in connection with experimental results on various reaction mechanisms. Finally, I describe the effects of uncertainties in the reconstruction of the incoming neutrino energy on oscillation parameters. The review argues that the precision era of neutrino physics also needs precision-era generators.

  17. Baseline Optimization for the Measurement of CP Violation, Mass Hierarchy, and $\\theta_{23}$ Octant in a Long-Baseline Neutrino Oscillation Experiment

    SciTech Connect

    Bass, M.; Bishai, M.; Cherdack, D.; Diwan, M.; Djurcic, Z.; Hernandez, J.; Lundberg, B.; Paolone, V.; Qian, X.; Rameika, R.; Whitehead, L.; Wilson, R. J.; Worcester, E.; Zeller, G.

    2015-03-19

    Next-generation long-baseline electron neutrino appearance experiments will seek to discover CP violation, determine the mass hierarchy and resolve the θ23 octant. In light of the recent precision measurements of θ13, we consider the sensitivity of these measurements in a study to determine the optimal baseline, including practical considerations regarding beam and detector performance. We conclude that a detector at a baseline of at least 1000 km in a wide-band muon neutrino beam is the optimal configuration.

  18. Computer Based Simulation of Laboratory Experiments.

    ERIC Educational Resources Information Center

    Edward, Norrie S.

    1997-01-01

    Examines computer based simulations of practical laboratory experiments in engineering. Discusses the aims and achievements of lab work (cognitive, process, psychomotor, and affective); types of simulations (model building and behavioral); and the strengths and weaknesses of simulations. Describes the development of a centrifugal pump simulation,…

  19. Computer Based Simulation of Laboratory Experiments.

    ERIC Educational Resources Information Center

    Edward, Norrie S.

    1997-01-01

    Examines computer based simulations of practical laboratory experiments in engineering. Discusses the aims and achievements of lab work (cognitive, process, psychomotor, and affective); types of simulations (model building and behavioral); and the strengths and weaknesses of simulations. Describes the development of a centrifugal pump simulation,…

  20. Long baseline neutrino oscillation experiment at the AGS. Physics design report

    SciTech Connect

    Beavis, D.; Carroll, A.; Chiang, I.; E889 Collaboration

    1995-04-01

    The authors present a design for a multi-detector long baseline neutrino oscillation experiment at the BNL AGS. It has been approved by the BNL-HENP-PAC as AGS Experiment 889. The experiment will search for oscillations in the {nu}{sub {mu}}, disappearance channel and the {nu}{sub {mu}} {leftrightarrow} {nu}{sub e} appearance channel by means of four identical neutrino detectors located 1, 3, 24, and 68km from the AGS neutrino source. Observed depletion of the {nu}{sub {mu}} flux (via quasi-elastic muon neutrino events, {nu}{sub {mu}}n {yields} {mu}{sup {minus}}p) in the far detectors not attended by an observed proportional increase of the {nu}{sub e} flux (via quasi-elastic electron neutrino events, {nu}{sub e}n {yields} e{sup {minus}}p) in those detectors will be prima facie evidence for the oscillation channel {nu}{sub {mu}} {leftrightarrow} {nu}{sub {tau}}. The experiment is directed toward exploration of the region of the neutrino oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}, suggested by the Kamiokande and IMB deep underground detectors but it will also explore a region more than two orders of magnitude larger than that of previous accelerator experiments. The experiment will run in a mode new to BNL. It will receive the fast extracted proton beam on the neutrino target approximately 20 hours per day when the AGS is not filling RHIC. A key aspect of the experimental design involves placing the detectors 1.5 degrees off the center line of the neutrino beam, which has the important advantage that the central value of the neutrino energy ({approx} 1 GeV) and the beam spectral shape are, to a good approximation, the same in all four detectors. The proposed detectors are massive, imaging, water Cherenkov detectors similar in large part to the Kamiokande and IMB detectors. The design has profited from their decade-long experience, and from the detector designs of the forthcoming SNO and SuperKamiokande detectors.

  1. The Transliminal Brain at Rest: Baseline EEG, Unusual Experiences, and Access to Unconscious Mental Activity

    PubMed Central

    Fleck, Jessica I.; Green, Deborah L.; Stevenson, Jennifer L.; Payne, Lisa; Bowden, Edward M.; Jung-Beeman, Mark; Kounios, John

    2008-01-01

    Transliminality reflects individual differences in the threshold at which unconscious processes or external stimuli enter into consciousness. Individuals high in transliminality possess characteristics such as magical ideation, belief in the paranormal, and creative personality traits, and also report the occurrence of manic/mystic experiences. The goal of the present research was to determine if resting brain activity differs for individuals high versus low in transliminality. We compared baseline EEG recordings (eyes-closed) between individuals high versus low in transliminality, assessed using The Revised Transliminality Scale of Lange et al. (2000). Identifying reliable differences at rest between high- and low-transliminality individuals would support a predisposition for transliminality-related traits. Individuals high in transliminality exhibited lower alpha, beta, and gamma power than individuals low in transliminality over left posterior association cortex and lower high alpha, low beta, and gamma power over the right superior temporal region. In contrast, when compared to individuals low in transliminality, individuals high in transliminality exhibited greater gamma power over the frontal-midline region. These results are consistent with prior research reporting reductions in left temporal/parietal activity, as well as the desynchronization of right temporal activity in schizotypy and related schizophrenia spectrum disorders. Further, differences between high- and low-transliminality groups extend existing theories linking altered hemispheric asymmetries in brain activity to a predisposition toward schizophrenia, paranormal beliefs, and unusual experiences. PMID:18814870

  2. Teaching Experiment Design by Computer Simulation

    ERIC Educational Resources Information Center

    Montgomery, David C.

    1973-01-01

    Describes an introductory physics experiment carried out by 24 students who used an IBM-360 Model-44 computer to stimulate Stokes' law. Discusses advantages of simulation programs in teaching experiment design. (CC)

  3. Can we probe intrinsic C P and T violations and nonunitarity at long baseline accelerator experiments?

    NASA Astrophysics Data System (ADS)

    Rout, Jogesh; Masud, Mehedi; Mehta, Poonam

    2017-04-01

    One of the fundamental parameters entering the neutrino oscillation framework is the leptonic C P phase δ13, and its measurement is an important goal of the planned long baseline experiments. It should be noted that ordinary matter effects complicate the determination of this parameter, and there are studies in the literature that deal with separation of intrinsic vs extrinsic C P violation. It is important to investigate the consequences of new physics effects that can not only hamper the measurement of δ13 but also impact the consequences of discrete symmetries such as C P , T , and unitarity in different oscillation channels. In the present work, we explore these discrete symmetries and implications on unitarity in the presence of two new physics scenarios (nonstandard interaction in propagation and the presence of sterile neutrinos) that serve as good examples of going beyond the standard scenario in different directions. We uncover the impact of new physics scenarios on disentangling intrinsic and extrinsic C P violation.

  4. Initial results from the CHOOZ long baseline reactor neutrino oscillation experiment

    NASA Astrophysics Data System (ADS)

    Apollonio, M.; Baldini, A.; Bemporad, C.; Caffau, E.; Cei, F.; Déclais, Y.; de Kerret, H.; Dieterle, B.; Etenko, A.; George, J.; Giannini, G.; Grassi, M.; Kozlov, Y.; Kropp, W.; Kryn, D.; Laiman, M.; Lane, C. E.; Lefièvre, B.; Machulin, I.; Martemyanov, A.; Martemyanov, V.; Mikaelyan, L.; Nicolò, D.; Obolensky, M.; Pazzi, R.; Pieri, G.; Price, L.; Riley, S.; Reeder, R.; Sabelnikov, A.; Santin, G.; Skorokhvatov, M.; Sobel, H.; Steele, J.; Steinberg, R.; Sukhotin, S.; Tomshaw, S.; Veron, D.; Vyrodov, V.

    1998-02-01

    Initial results are presented from CHOOZ, a long-baseline reactor-neutrino vacuum-oscillation experiment. The data reported here were taken during the period March to October 1997, when the two reactors ran at combined power levels varying from zero to values approaching their full rated power of 8.5 (thermal). Electron antineutrinos from the reactors were detected by a liquid scintillation calorimeter located at a distance of about 1. The detector was constructed in a tunnel protected from cosmic rays by a 300 rock overburden. This massive shielding strongly reduced potentially troublesome backgrounds due to cosmic-ray muons, leading to a background rate of about one event per day, more than an order of magnitude smaller than the observed neutrino signal. From the statistical agreement between detected and expected neutrino event rates, we find (at 90% confidence level) no evidence for neutrino oscillations in the disappearance mode for the parameter region given approximately by for maximum mixing and for large .

  5. A search for neutrino oscillations using the CHOOZ 1 km baseline reactor neutrino experiment

    NASA Astrophysics Data System (ADS)

    George, Jean

    1999-10-01

    Neutrino oscillation searches are an active field of research due to the implications their discovery may have for the solar neutrino anomaly as well as for the atmospheric neutrino anomaly. Their discovery may also have broad ramifications for the Standard Model of Particle Physics as a whole. Results from an oscillation search using the CHOOZ long baseline reactor neutrino experiment are presented in this thesis. These results are based on the data taken from June 1997 through April 1998 when the two reactors ran at combined thermal power levels ranging from zero power to their full power level of 8.5 GW. Electron flavored antineutrinos emanating from the reactors were detected through the inverse beta decay channel using a liquid scintillating calorimeter located at a distance of approximately 1 km from the reactor sources. The underground experimental site (300 MWE) provided natural shielding from the background of cosmic ray muons-leading to a background rate more than an order of magnitude lower than the full power signal rate. From the agreement between the detected and expected neutrino event rates no evidence for neutrino oscillations was found (at the 90% C.L.) for the oscillation parameter space governed by Δm 2 > 0.8 × 10-3 eV2 for maximal mixing and by sin2 2Θ > 0.18 for large values of Δm2.

  6. Flight Technical Error Analysis of the SATS Higher Volume Operations Simulation and Flight Experiments

    NASA Technical Reports Server (NTRS)

    Williams, Daniel M.; Consiglio, Maria C.; Murdoch, Jennifer L.; Adams, Catherine H.

    2005-01-01

    This paper provides an analysis of Flight Technical Error (FTE) from recent SATS experiments, called the Higher Volume Operations (HVO) Simulation and Flight experiments, which NASA conducted to determine pilot acceptability of the HVO concept for normal operating conditions. Reported are FTE results from simulation and flight experiment data indicating the SATS HVO concept is viable and acceptable to low-time instrument rated pilots when compared with today s system (baseline). Described is the comparative FTE analysis of lateral, vertical, and airspeed deviations from the baseline and SATS HVO experimental flight procedures. Based on FTE analysis, all evaluation subjects, low-time instrument-rated pilots, flew the HVO procedures safely and proficiently in comparison to today s system. In all cases, the results of the flight experiment validated the results of the simulation experiment and confirm the utility of the simulation platform for comparative Human in the Loop (HITL) studies of SATS HVO and Baseline operations.

  7. Ion exchange - Simulation and experiment

    NASA Technical Reports Server (NTRS)

    Herrmann, Cal C.; Finn, John E.

    1991-01-01

    A FORTRAN program for simulating multicomponent adsorption by ion-exchange resins was adapted for use as both an ASPEN-callable module and as a free-standing simulator of the ion-exchange bed. Four polystyrene-divinylbenzene sulfonic acid resins have been characterized for three principal ions. It is concluded that a chelating resin appears appropriate as a heavy-metal trap. The same ASPEN-callable module is used to model this resin when Wilson parameters can be obtained.

  8. Ion exchange - Simulation and experiment

    NASA Technical Reports Server (NTRS)

    Herrmann, Cal C.; Finn, John E.

    1991-01-01

    A FORTRAN program for simulating multicomponent adsorption by ion-exchange resins was adapted for use as both an ASPEN-callable module and as a free-standing simulator of the ion-exchange bed. Four polystyrene-divinylbenzene sulfonic acid resins have been characterized for three principal ions. It is concluded that a chelating resin appears appropriate as a heavy-metal trap. The same ASPEN-callable module is used to model this resin when Wilson parameters can be obtained.

  9. An Experiment in Simulation Coercion

    DTIC Science & Technology

    2003-01-01

    hockey puck simulation.’’ Instead of simulating the hockey puck as a point mass that changes direction when forces are applied to it, the hockey ... puck model enforces limits on how sharply the hockey puck can turn within a given period of time. The hockey puck travels at a constant speed... hockey puck does not follow a prescribed path exactly, but veers slightly off the path when it reacts to a curve too early or does not

  10. Comparison of Baseline Wander Removal Techniques considering the Preservation of ST Changes in the Ischemic ECG: A Simulation Study

    PubMed Central

    Pilia, Nicolas; Schulze, Walther H. W.; Dössel, Olaf

    2017-01-01

    The most important ECG marker for the diagnosis of ischemia or infarction is a change in the ST segment. Baseline wander is a typical artifact that corrupts the recorded ECG and can hinder the correct diagnosis of such diseases. For the purpose of finding the best suited filter for the removal of baseline wander, the ground truth about the ST change prior to the corrupting artifact and the subsequent filtering process is needed. In order to create the desired reference, we used a large simulation study that allowed us to represent the ischemic heart at a multiscale level from the cardiac myocyte to the surface ECG. We also created a realistic model of baseline wander to evaluate five filtering techniques commonly used in literature. In the simulation study, we included a total of 5.5 million signals coming from 765 electrophysiological setups. We found that the best performing method was the wavelet-based baseline cancellation. However, for medical applications, the Butterworth high-pass filter is the better choice because it is computationally cheap and almost as accurate. Even though all methods modify the ST segment up to some extent, they were all proved to be better than leaving baseline wander unfiltered. PMID:28373893

  11. Comparison of Baseline Wander Removal Techniques considering the Preservation of ST Changes in the Ischemic ECG: A Simulation Study.

    PubMed

    Lenis, Gustavo; Pilia, Nicolas; Loewe, Axel; Schulze, Walther H W; Dössel, Olaf

    2017-01-01

    The most important ECG marker for the diagnosis of ischemia or infarction is a change in the ST segment. Baseline wander is a typical artifact that corrupts the recorded ECG and can hinder the correct diagnosis of such diseases. For the purpose of finding the best suited filter for the removal of baseline wander, the ground truth about the ST change prior to the corrupting artifact and the subsequent filtering process is needed. In order to create the desired reference, we used a large simulation study that allowed us to represent the ischemic heart at a multiscale level from the cardiac myocyte to the surface ECG. We also created a realistic model of baseline wander to evaluate five filtering techniques commonly used in literature. In the simulation study, we included a total of 5.5 million signals coming from 765 electrophysiological setups. We found that the best performing method was the wavelet-based baseline cancellation. However, for medical applications, the Butterworth high-pass filter is the better choice because it is computationally cheap and almost as accurate. Even though all methods modify the ST segment up to some extent, they were all proved to be better than leaving baseline wander unfiltered.

  12. Simulation and Introductory Pharmacy Practice Experiences

    PubMed Central

    Lin, Katherine; Wadelin, Jeffrey W.; Vlasses, Peter H.

    2011-01-01

    This paper reviews the literature on the various types of simulation and their incorporation into health professions curricula, describes how simulation training is recognized in other professions, and evaluates the feasibility of integrating simulation into experiential education programs of colleges and schools of pharmacy. The Accreditation Council for Pharmacy Education (ACPE) Board of Directors develop standards and guidelines on the use of simulation as part of introductory pharmacy practice experiences within the doctor of pharmacy (PharmD) curriculum. PMID:22345728

  13. Diffusion Processes: Experiment, Theory, Simulations

    NASA Astrophysics Data System (ADS)

    Pekalski, Andrzej

    The articles in this book reflect the omnipresence of diffusion processes in the natural sciences. They describe experimental results as well as theoretical models and computer simulations, and address a wide readership including graduate students. The problems treated stem from physics, astronomy, physical chemistry, biology, and medicine. The papers are presented in a tutorial style and reflect the present-day trends in the field.

  14. Investigation on aerodynamic characteristics of baseline-II E-2 blended wing-body aircraft with canard via computational simulation

    NASA Astrophysics Data System (ADS)

    Nasir, Rizal E. M.; Ali, Zurriati; Kuntjoro, Wahyu; Wisnoe, Wirachman

    2012-06-01

    Previous wind tunnel test has proven the improved aerodynamic charasteristics of Baseline-II E-2 Blended Wing-Body (BWB) aircraft studied in Universiti Teknologi Mara. The E-2 is a version of Baseline-II BWB with modified outer wing and larger canard, solely-designed to gain favourable longitudinal static stability during flight. This paper highlights some results from current investigation on the said aircraft via computational fluid dynamics simulation as a mean to validate the wind tunnel test results. The simulation is conducted based on standard one-equation turbulence, Spalart-Allmaras model with polyhedral mesh. The ambience of the flight simulation is made based on similar ambience of wind tunnel test. The simulation shows lift, drag and moment results to be near the values found in wind tunnel test but only within angles of attack where the lift change is linear. Beyond the linear region, clear differences between computational simulation and wind tunnel test results are observed. It is recommended that different type of mathematical model be used to simulate flight conditions beyond linear lift region.

  15. Simulation of GRETINA Lifetime Experiment

    NASA Astrophysics Data System (ADS)

    Littley, Cody; Iwasaki, Hironori; Lemasson, Antoine

    2011-10-01

    In order to understand properties of exotic atomic nuclei, the research group has developed a method to measure the rate of decay of excited states in certain unstable isotopes, for example 66Fe. By measuring the Doppler shift of gamma rays with a so-called plunger device it is possible to deduce with great accuracy the excited-state lifetime. This technique, which is called the Recoil Distance Doppler-shift Method, has precision on the order of one pico second. I will present the development a simulation software package which will help the research team to quantize and to analyze the data from experimental runs. This software is based upon existing software which was used for simulations of the SeGA project. It has been modified to support the GRETINA detector, which is used in the experimental setup for the lifetime measurements. The software makes use GEANT and ROOT toolkits, which are essential for the calculations of the interactions of particles with the detector and the recording of that data.

  16. Proton irradiated graphite grades for a long baseline neutrino facility experiment

    NASA Astrophysics Data System (ADS)

    Simos, N.; Nocera, P.; Zhong, Z.; Zwaska, R.; Mokhov, N.; Misek, J.; Ammigan, K.; Hurh, P.; Kotsina, Z.

    2017-07-01

    In search of a low-Z pion production target for the Long Baseline Neutrino Facility (LBNF) of the Deep Underground Neutrino Experiment (DUNE) four graphite grades were irradiated with protons in the energy range of 140-180 MeV, to peak fluence of ˜6.1 ×1020 p /cm2 and irradiation temperatures between 120 - 200 °C . The test array included POCO ZXF-5Q, Toyo-Tanso IG 430, Carbone-Lorraine 2020 and SGL R7650 grades of graphite. Irradiation was performed at the Brookhaven Linear Isotope Producer. Postirradiation analyses were performed with the objective of (a) comparing their response under the postulated irradiation conditions to guide a graphite grade selection for use as a pion target and (b) understanding changes in physical and mechanical properties as well as microstructure that occurred as a result of the achieved fluence and in particular at this low-temperature regime where pion graphite targets are expected to operate. A further goal of the postirradiation evaluation was to establish a proton-neutron correlation damage on graphite that will allow for the use of a wealth of available neutron-based damage data in proton-based studies and applications. Macroscopic postirradiation analyses as well as energy dispersive x-ray diffraction of 200 KeV x rays at the NSLS synchrotron of Brookhaven National Laboratory were employed. The macroscopic analyses revealed differences in the physical and strength properties of the four grades with behavior however under proton irradiation that qualitatively agrees with that reported for graphite under neutrons for the same low temperature regime and in particular the increase of thermal expansion, strength and Young's modulus. The proton fluence level of ˜1020 cm-2 where strength reaches a maximum before it begins to decrease at higher fluences has been identified and it agrees with neutron-induced changes. X-ray diffraction analyses of the proton irradiated graphite revealed for the first time the similarity in

  17. Proton irradiated graphite grades for a long baseline neutrino facility experiment

    DOE PAGES

    Simos, N.; Nocera, P.; Zhong, Z.; ...

    2017-07-24

    In search of a low-Z pion production target for the Long Baseline Neutrino Facility (LBNF) of the Deep Underground Neutrino Experiment (DUNE) four graphite grades were irradiated with protons in the energy range of 140–180 MeV, to peak fluence of ~6.1×1020 p/cm2 and irradiation temperatures between 120–200 °C. The test array included POCO ZXF-5Q, Toyo-Tanso IG 430, Carbone-Lorraine 2020 and SGL R7650 grades of graphite. Irradiation was performed at the Brookhaven Linear Isotope Producer. Postirradiation analyses were performed with the objective of (a) comparing their response under the postulated irradiation conditions to guide a graphite grade selection for use as a pionmore » target and (b) understanding changes in physical and mechanical properties as well as microstructure that occurred as a result of the achieved fluence and in particular at this low-temperature regime where pion graphite targets are expected to operate. A further goal of the postirradiation evaluation was to establish a proton-neutron correlation damage on graphite that will allow for the use of a wealth of available neutron-based damage data in proton-based studies and applications. Macroscopic postirradiation analyses as well as energy dispersive x-ray diffraction of 200 KeV x rays at the NSLS synchrotron of Brookhaven National Laboratory were employed. The macroscopic analyses revealed differences in the physical and strength properties of the four grades with behavior however under proton irradiation that qualitatively agrees with that reported for graphite under neutrons for the same low temperature regime and in particular the increase of thermal expansion, strength and Young’s modulus. The proton fluence level of ~1020 cm-2 where strength reaches a maximum before it begins to decrease at higher fluences has been identified and it agrees with neutron-induced changes. X-ray diffraction analyses of the proton irradiated graphite revealed for the first time the similarity in

  18. An evaluation of water vapor radiometer data for calibration of the wet path delay in very long baseline interferometry experiments

    NASA Technical Reports Server (NTRS)

    Kuehn, C. E.; Himwich, W. E.; Clark, T. A.; Ma, C.

    1991-01-01

    The internal consistency of the baseline-length measurements derived from analysis of several independent VLBI experiments is an estimate of the measurement precision. The paper investigates whether the inclusion of water vapor radiometer (WVR) data as an absolute calibration of the propagation delay due to water vapor improves the precision of VLBI baseline-length measurements. The paper analyzes 28 International Radio Interferometric Surveying runs between June 1988 and January 1989; WVR measurements were made during each session. The addition of WVR data decreased the scatter of the length measurements of the baselines by 5-10 percent. The observed reduction in the scatter of the baseline lengths is less than what is expected from the behavior of the formal errors, which suggest that the baseline-length measurement precision should improve 10-20 percent if WVR data are included in the analysis. The discrepancy between the formal errors and the baseline-length results can be explained as the consequence of systematic errors in the dry-mapping function parameters, instrumental biases in the WVR and the barometer, or both.

  19. An evaluation of water vapor radiometer data for calibration of the wet path delay in very long baseline interferometry experiments

    NASA Technical Reports Server (NTRS)

    Kuehn, C. E.; Himwich, W. E.; Clark, T. A.; Ma, C.

    1991-01-01

    The internal consistency of the baseline-length measurements derived from analysis of several independent VLBI experiments is an estimate of the measurement precision. The paper investigates whether the inclusion of water vapor radiometer (WVR) data as an absolute calibration of the propagation delay due to water vapor improves the precision of VLBI baseline-length measurements. The paper analyzes 28 International Radio Interferometric Surveying runs between June 1988 and January 1989; WVR measurements were made during each session. The addition of WVR data decreased the scatter of the length measurements of the baselines by 5-10 percent. The observed reduction in the scatter of the baseline lengths is less than what is expected from the behavior of the formal errors, which suggest that the baseline-length measurement precision should improve 10-20 percent if WVR data are included in the analysis. The discrepancy between the formal errors and the baseline-length results can be explained as the consequence of systematic errors in the dry-mapping function parameters, instrumental biases in the WVR and the barometer, or both.

  20. Using Syllable-Timed Speech to Treat Preschool Children Who Stutter: A Multiple Baseline Experiment

    ERIC Educational Resources Information Center

    Trajkovski, Natasha; Andrews, Cheryl; Onslow, Mark; Packman, Ann; O'Brian, Sue; Menzies, Ross

    2009-01-01

    This report presents the results of an experimental investigation of the effects of a syllable-timed speech treatment on three stuttering preschool children. Syllable-timed speech involves speaking with minimal differentiation in linguistic stress across syllables. Three children were studied in a multiple baseline across participants design, with…

  1. The Employment Experiences of Public Housing Residents: Findings from the Jobs-Plus Baseline Survey.

    ERIC Educational Resources Information Center

    Martinez, John M.

    A survey collected baseline data about public housing communities and residents just prior to the start of the Jobs-Plus program. The data were from all working-age, nondisabled heads of households in eight public housing developments in seven cities with customarily high rates of joblessness and reliance on welfare. The developments were part of…

  2. Using Syllable-Timed Speech to Treat Preschool Children Who Stutter: A Multiple Baseline Experiment

    ERIC Educational Resources Information Center

    Trajkovski, Natasha; Andrews, Cheryl; Onslow, Mark; Packman, Ann; O'Brian, Sue; Menzies, Ross

    2009-01-01

    This report presents the results of an experimental investigation of the effects of a syllable-timed speech treatment on three stuttering preschool children. Syllable-timed speech involves speaking with minimal differentiation in linguistic stress across syllables. Three children were studied in a multiple baseline across participants design, with…

  3. Screening for acrylate/methacrylate allergy in the baseline series: our experience in Sweden and Singapore.

    PubMed

    Goon, Anthony Teik-Jin; Bruze, Magnus; Zimerson, Erik; Goh, Chee-Leok; Soo-Quee Koh, David; Isaksson, Marléne

    2008-11-01

    No studies to specifically determine the prevalence of contact allergy to acrylates/methacrylates in patch tested populations have been published. To determine the prevalence of acrylate/methacrylate allergy in all patients tested to the baseline patch test series. Five acrylate/methacrylate allergens (2-hydroxyethyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate, triethylene glycol diacrylate, and 2-hydroxypropyl acrylate) were included in the baseline series for at least 2 years in Malmö and Singapore. Thirty-eight patients in total had reacted to acrylate/methacrylate allergens in the baseline series during the study period in both populations. In Malmö, there were 26 (1.4%) patients with positive patch tests to acrylate/methacrylate allergens, 14 of whom had relevant reactions. In Singapore, there were 12 (1.0%) patients with positive patch tests to acrylate/methacrylate allergens, but only 1 had relevant reactions. If we had not added acrylate/methacrylate allergens to the baseline series, we would not have patch tested 13/26 (50%) of the positive reactors in Malmö and 11/12 (92%) of the positive reactors in Singapore. The overall proportion of missed positive reactors would have been 24/38 (63%). The prevalence of acrylate/methacrylate allergy in our patch tested dermatitis populations is 1.4% in Malmö and 1.0% in Singapore.

  4. MCNP simulations of material exposure experiments (u)

    SciTech Connect

    Temple, Brian A

    2010-12-08

    Simulations of proposed material exposure experiments were performed using MCNP6. The experiments will expose ampules containing different materials of interest with radiation to observe the chemical breakdown of the materials. Simulations were performed to map out dose in materials as a function of distance from the source, dose variation between materials, dose variation due to ampule orientation, and dose variation due to different source energy. This write up is an overview of the simulations and will provide guidance on how to use the data in the spreadsheet.

  5. A Program for Simulated Thermodynamic Experiments.

    ERIC Educational Resources Information Center

    Olds, Dan W.

    A time-sharing FORTRAN program is described. It was created to allow a student to design and perform classical thermodynamic experiments on three models of a working substance. One goal was to develop a simulation which gave the student maximum freedom and responsibility in the design of the experiment and provided only the primary experimental…

  6. An Introductory Scattering Experiment by Simulation

    ERIC Educational Resources Information Center

    Merrill, John R.; Morrow, Richard A.

    1970-01-01

    Describes an introductory physics experiment concerned with scattering particles off various force centers. The experiment uses simulation techniques and a computer. The scattering is classical, and the student examines plots of computed particle trajectories. The results illustrate the concepts of differential corss-section, total cross-section,…

  7. Observing System Simulation Experiments: An Overview

    NASA Technical Reports Server (NTRS)

    Prive, Nikki C.; Errico, Ronald M.

    2016-01-01

    An overview of Observing System Simulation Experiments (OSSEs) will be given, with focus on calibration and validation of OSSE frameworks. Pitfalls and practice will be discussed, including observation error characteristics, incestuousness, and experimental design. The potential use of OSSEs for investigation of the behaviour of data assimilation systems will be explored, including some results from experiments using the NASAGMAO OSSE.

  8. Observing System Simulation Experiments: An Overview

    NASA Technical Reports Server (NTRS)

    Prive, Nikki C.; Errico, Ronald M.

    2016-01-01

    An overview of Observing System Simulation Experiments (OSSEs) will be given, with focus on calibration and validation of OSSE frameworks. Pitfalls and practice will be discussed, including observation error characteristics, incestuousness, and experimental design. The potential use of OSSEs for investigation of the behaviour of data assimilation systems will be explored, including some results from experiments using the NASAGMAO OSSE.

  9. Monte Carlo Simulation of Cosmogenic Processes for the SURF Experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Mei, Dongming

    2012-03-01

    Sanford Underground Research Facility (SURF) at Homestake Mine will host several experiments in searching for dark matter, neutrinoless double-beta decay, and neutrino oscillation with a long baseline neutrino beam. The muon-induced cosmogenic processes are background matter to the planned experiments and those cosmogenic processes will directly impact the design of the experimental shielding to achieve the target sensitivity. Therefore understanding the muon-induced processes is important. We conduct a full Monte Carlo simulation to characterize the muon-induced background level for SURF. Detailed mountain profile and averaged rock composition are considered for muon attenuation from the surface to the 4850-ft level. We report the simulation results for the muon-induced neutron flux, energy spectrum, and angular distribution at the 4850-ft level.

  10. Early experience with simulated trauma resuscitation

    PubMed Central

    McLellan, Barry A.

    1999-01-01

    Although trauma resuscitation is best taught through direct exposure with hands-on experience, the opportunities for this type of teaching in Canada are limited by the relatively low incidence of serious injury and the consolidation of trauma care to a small number of centres. Simulators have been used extensively outside the health care environment and more recently have been used by anesthetists to simulate intraoperative crises. In this paper early experience using a realistic mannequin, controlled by a remote computer, that simulates a variety of physiologic and injury specific variables is presented. The resource implications of simulated resuscitation are reviewed, including one-time and operating costs. Simulated trauma resuscitation may be an educational alternative to “real-life” trauma resuscitation, but careful evaluation of the benefits and resource implications of this type of teaching through well-designed research studies will be important. PMID:10372017

  11. Pyro shock simulation: Experience with the MIPS simulator

    NASA Technical Reports Server (NTRS)

    Dwyer, Thomas J.; Moul, David S.

    1988-01-01

    The Mechanical Impulse Pyro Shock (MIPS) Simulator at GE Astro Space Division is one version of a design that is in limited use throughout the aerospace industry, and is typically used for component shock testing at levels up to 10,000 response g's. Modifications to the force imput, table and component boundary conditions have allowed a range of test conditions to be achieved. Twelve different designs of components with weights up to 23 Kg are in the process or have completed qualification testing in the Dynamic Simulation Lab at GE in Valley Forge, Pa. A summary of the experience gained through the use of this simulator is presented as well as examples of shock experiments that can be readily simulated at the GE Astro MIPS facility.

  12. Single-session baseline virtual reality simulator scores predict technical performance for laparoscopic colectomy: a study in the swine model.

    PubMed

    Araujo, Sergio Eduardo Alonso; Seid, Victor E; Bertoncini, Alexandre B; Horcel, Lucas A; Nahas, Sergio C; Cecconello, Ivan

    2014-01-01

    Virtual reality (VR) simulation helps reducing the learning curve of laparoscopic colectomy. Moreover, it may be used to ascertain surgeons' pretraining skills. It was aimed to establish predictive validity of specific parameters gathered during VR simulation training on sigmoid colectomy and whether simulator parameters correlate with technical performance during the same operation in a swine model. Surgeons novice to laparoscopic colectomy underwent a single VR simulation session on sigmoid colectomy. Next, all participants performed a laparoscopic sigmoidectomy in the swine. Operations were recorded. Performance evaluation was conducted by 2 board-certified colorectal surgeons blinded to surgeons' simulator scores using an instrument specific to laparoscopic colectomy. For each participant, a mean score of specific skills was calculated. Linear regression analysis was used to identify simulator parameters that were best related to the score. The stepwise method was used to select parameters. The magnitude of the regression model was measured by the coefficient of determination (R(2)) value. The University of Sao Paulo Medical Center is a high-volume, public practice, university-affiliated hospital. A total of 14 first-year residents in digestive tract surgery were included. Analysis of variance demonstrated that the regression model was significant (p = 0.0001), and an association between simulation scores and specific skills was confirmed. The R(2) value was 99%. The VR simulator parameters that strongly correlated with specific skills during laparoscopic colectomy in the swine were safe use of electrosurgery/energy device and safety of medial-to-lateral dissection. A single VR simulation session for novice surgeons in the sigmoid colectomy module generates baseline scores that highly correlated with performance of specific skills during a laparoscopic colectomy in the swine. This information may be useful in an attempt to tailor VR simulator practice according

  13. Initial experience establishing an EUV baseline lithography process for manufacturability assessment

    NASA Astrophysics Data System (ADS)

    Wood, O. R., II; Back, D.; Brainard, R.; Denbeaux, G.; Goldfarb, D.; Goodwin, F.; Hartley, J.; Kimmel, K.; Koay, C.; La Fontaine, B.; Mackey, J.; Martinick, B.; Montgomery, W.; Naulleau, P.; Okoroanyanwu, U.; Petrillo, K.; Pierson, B.; Tittnich, M.; Trogisch, S.; Wallow, T.; Wei, Y.

    2007-03-01

    The International Venture for Nanolithography (INVENT) initiative announced in mid 2005, a unique industry-university consortium between the College of Nanoscale Science and Engineering at Albany and a group of leading edge integrated device manufacturers, has launched an extensive R&D program on EUV lithography (EUVL). The overall scope of the INVENT EUVL program, the status of our efforts to establish a baseline lithography process on a full-field EUVL scanner, and our progress in evaluating EUV resist materials, in designing a custom reticle for scanner characterization and in developing an actinic EUV mask imaging microscope, are discussed.

  14. Simulations of Boundary Turbulence in Tokamak Experiments

    SciTech Connect

    Nevins, W M; Xu, X Q; Carlstrom, T N; Cohen, R H; Groebner, R; Jennings, T; LaBombard, B; Maqueda, R A; Mazurenko, A; McKee, G R; Moyer, R; Mossessian, D; Porkolab, M; Porter, G D; Rensink, M E; Rhodes, T L; Rognlien, T D; Rost, C; Snipes, J; Stotler, D P; Terry, J; Zweben, S

    2002-10-11

    Comparisons between the boundary plasma turbulence observed in the BOUT code and experiments on C-Mod, NSTX, and DIII-D are presented. BOUT is a 3D non-local electromagnetic turbulence simulation code which models boundary-plasma turbulence in a realistic divertor geometry using the modified Braginskii equations for plasma vorticity, density, the electron and ion temperatures and parallel momenta. Many features of the Quasi-Coherent (QC) mode, observed at high densities during enhanced D-alpha (EDA) H-Mode in Alcator C-Mod, are reproduced in BOUT simulations. The spatial structure of boundary plasma turbulence as observed by gas puff imaging (GPI) from discharges on NSTX and C-Mod are in general (NSTX) to good (CMod) agreement with BOUT simulations. Finally, BOUT simulations of DIII-D L-mode experiments near the Hmode transition threshold are in broad agreement with the experimental results.

  15. Results and Status of the T2K and NOvA long-baseline neutrino experiments

    NASA Astrophysics Data System (ADS)

    Muether, Mathew

    2016-03-01

    The discovery of neutrino oscillations and the resulting implication that neutrinos have mass, recently awarded the Nobel Prize in Physics, has bolstered a world-wide effort to exploit this effect as a handle on the properties of neutrinos. In the decades since the initial discovery of neutrino oscillations, great strides have been made in understanding the nature of these elusive particles, yet important and fundamental questions remain open, such as: How are the neutrino masses ordered? And Do neutrinos and antineutrinos oscillate differently? The current generation of accelerator based long-baseline neutrino oscillation experiments, T2K in Japan and NOvA in the United States, are actively pursuing the answers to these questions. In this talk, I will review the recent results and current status of the T2K and NOvA long-baseline neutrino experiments.

  16. Experiments with the KITE attitude control simulator

    NASA Technical Reports Server (NTRS)

    Powell, J. David; Kline-Schoder, Robert

    1989-01-01

    Simulation experiments are conducted to test an attitude control technique for tethered satellites using the tether tension force to generate control torques by moving the tether attach point relative to the satellite center of mass. A scaled, one-dimensional, air-bearing supported laboratory simulation of the Kinetic Isolation Tether Experiment shows that the attitude of the simulator can be regulated to within 0.75 arcsec with a bandwidth of about 0.1 Hz. The control design includes a state estimator to calculate the vehicle mass center and to calculate the effect of the stepper motor dynamics on the state estimate. Results are presented from closed-loop attitude control experiments to verify the attitude control technique.

  17. Simulation of MTF experiments at General Fusion

    NASA Astrophysics Data System (ADS)

    Reynolds, Meritt; Froese, Aaron; Barsky, Sandra; Devietien, Peter; Toth, Gabor; Brennan, Dylan; Hooper, Bick

    2016-10-01

    General Fusion (GF) aims to develop a magnetized target fusion (MTF) power plant based on compression of magnetically-confined plasma by liquid metal. GF is testing this compression concept by collapsing solid aluminum liners onto spheromak or tokamak plasmas. To simulate the evolution of the compressing plasma in these experiments, we integrated a moving-mesh method into a finite-volume MHD code (VAC). The single-fluid model includes temperature-dependent resistivity and anisotropic heat transport. The trajectory of the liner is based on experiments and LS-DYNA simulations. During compression the geometry remains axially symmetric, but the MHD simulation is fully 3D to capture ideal and resistive plasma instabilities. We compare simulation to experiment through the primary diagnostic of Mirnov probes embedded in the inner coaxial surface against which the magnetic flux and plasma are compressed by the imploding liner. The MHD simulation reproduces the appearance of n=1 mode activity observed in experiments performed in negative D-shape geometry (MRT and PROSPECTOR machines). The same code predicts more favorable compression in spherical tokamak geometry, having positive D-shape (SPECTOR machine).

  18. Neutrino Scattering Uncertainties and their Role in Long Baseline Oscillation Experiments

    SciTech Connect

    D.A. Harris; G. Blazey; Arie Bodek; D. Boehnlein; S. Boyd; William Brooks; Antje Bruell; Howard S. Budd; R. Burnstein; D. Casper; A. Chakravorty; Michael Christy; Jesse Chvojka; M.A.C. Cummings; P. deBarbaro; D. Drakoulakos; J. Dunmore; Rolf Ent; Hugh Gallagher; David Gaskell; Ronald Gilman; Charles Glashausser; Wendy Hinton; Xiaodong Jiang; T. Kafka; O. Kamaev; Cynthia Keppel; M. Kostin; Sergey Kulagin; Gerfried Kumbartzki; Steven Manly; W.A. Mann; Kevin Mcfarland-porter; Wolodymyr Melnitchouk; Jorge Morfin; D. Naples; John Nelson; Gabriel Niculescu; Maria-ioana Niculescu; W. Oliver; Michael Paolone; Emmanuel Paschos; A. Pla-Dalmau; Ronald Ransome; C. Regis; P. Rubinov; V. Rykalin; Willis Sakumoto; P. Shanahan; N. Solomey; P. Spentzouris; P. Stamoulis; G. Tzanakos; Stephen Wood; F.X. Yumiceva; B. Ziemer; M. Zois

    2004-10-01

    The field of oscillation physics is about to make an enormous leap forward in statistical precision: first through the MINOS experiment in the coming year, and later through the NOvA and T2K experiments. Because of the relatively poor understanding of neutrino interactions in the energy ranges of these experiments, there are systematics that can arise in interpreting far detector data that can be as large as or even larger than the expected statistical uncertainties. We describe how these systematic errors arise, and how specific measurements in a dedicated neutrino scattering experiment like MINERvA can reduce the cross section systematic errors to well below the statistical errors.

  19. Baseline neoclassical scaling law on H-mode pedestal width from XGC0 kinetic simulation

    NASA Astrophysics Data System (ADS)

    Park, Gunyoung; Chang, C. S.; Ku, S.

    2009-11-01

    In the H-mode pedestal before the ELM onset, nonlocal neoclassical self-organization is an important physical effect, to set the baseline pedestal width scaling law. Deviation from the neoclassical scaling will define the anomalous scaling. The neoclassical self-organization includes effects from the self-consistent radial electric field shear, strong magnetic field shear, ion-orbit loss across the last closed magnetic surface, finite ion banana width, particle source from neutral ionization, heat flux from the core plasma, and collisional transport. XGC0 code is used to perform an inter-machine study of the neoclassical pedestal scaling law between two representative devices DIII-D (low-B, low collisionality) and C- Mod (high-B, high collisionality). Anomalous scaling component in the experimental pedestal width data will be separated out from the neoclassical component. Prediction for ITER pedestal will be attempted based upon the combined neoclassical (theoretical) and anomalous (empirical) scaling laws obtained in this study. This ion-electron study indicates that the neoclassical pedestal width is broader than the previous ion only study results, closer to experimental pedestal width.

  20. A Prospective Study of Pravastatin in the Elderly at Risk (PROSPER): Screening Experience and Baseline Characteristics

    PubMed Central

    Ford, Ian; Blauw, Gerard Jan; Murphy, Michael B; Shepherd, James; Cobbe, Stuart M; Bollen, Edward LEM; Buckley, Brendan M; Jukema, J Wouter; Hyland, Michael; Gaw, Allan; Lagaay, A Margot; Perry, Ivan J; Macfarlane, Peter; Norrie, John; Meinders, A Edo; Sweeney, Brian J; Packard, Chris J; Westendorp, Rudi GJ; Twomey, Cillian; Stott, David J

    2002-01-01

    Background PROSPER was designed to investigate the benefits of treatment with pravastatin in elderly patients for whom a typical doctor might consider the prescription of statin therapy to be a realistic option. Methods The PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) is a randomised, double blind, placebo-controlled trial to test the hypothesis that treatment with pravastatin (40 mg/day) will reduce the risk of coronary heart disease death, non-fatal myocardial infarction, and fatal or non-fatal stroke in elderly men and women with pre-existing vascular disease or with significant risk of developing this condition. Results In Scotland, Ireland, and the Netherlands, 23,770 individuals were screened, and 5,804 subjects (2,804 men and 3,000 women), aged 70 to 82 years (average 75 years) and with baseline cholesterol 4.0–9.0 mmol/l, were randomised. Randomised subjects had similar distributions with respect to age, blood pressure, and body mass index when compared to the entire group of screenees, but had a higher prevalence of smoking, diabetes, hypertension, and a history of vascular disease. The average total cholesterol level at baseline was 5.4 mmol/l (men) and 6.0 mmol/l (women). Conclusions Compared with previous prevention trials of cholesterol-lowering drugs, the PROSPER cohort is significantly older and for the first time includes a majority of women. The study, having achieved its initial goal of recruiting more than 5,500 elderly high-risk men and women, aims to complete all final subject follow-up visits in the first half of 2002 with the main results being available in the fourth quarter of 2002. PMID:12097148

  1. Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE): Conceptual Design Report. Volume 3: Long-Baseline Neutrino Facility for DUNE

    SciTech Connect

    Strait, James; McCluskey, Elaine; Lundin, Tracy; Willhite, Joshua; Hamernik, Thomas; Papadimitriou, Vaia; Marchionni, Alberto; Kim, Min Jeong; Nessi, Marzio; Montanari, David; Heavey, Anne

    2016-01-21

    This volume of the LBNF/DUNE Conceptual Design Report covers the Long-Baseline Neutrino Facility for DUNE and describes the LBNF Project, which includes design and construction of the beamline at Fermilab, the conventional facilities at both Fermilab and SURF, and the cryostat and cryogenics infrastructure required for the DUNE far detector.

  2. Psychology on Computers: Simulations, Experiments and Projects.

    ERIC Educational Resources Information Center

    Belcher, Duane M.; Smith, Stephen D.

    PSYCOM is a unique mixed media package which combines high interest projects on the computer with a written text of expository material. It goes beyond most computer-assisted instruction which emphasizes drill and practice and testing of knowledge. A project might consist of a simulation or an actual experiment, or it might be a demonstration, a…

  3. Psychology on Computers: Simulations, Experiments and Projects.

    ERIC Educational Resources Information Center

    Belcher, Duane M.; Smith, Stephen D.

    PSYCOM is a unique mixed media package which combines high interest projects on the computer with a written text of expository material. It goes beyond most computer-assisted instruction which emphasizes drill and practice and testing of knowledge. A project might consist of a simulation or an actual experiment, or it might be a demonstration, a…

  4. Introduction to Observing System Simulation Experiments (OSSEs)

    NASA Technical Reports Server (NTRS)

    Prive, Nikki C.

    2014-01-01

    This presentation gives a brief overview of Observing System Simulation Experiments (OSSEs), including what OSSEs are, and how and why they are performed. The intent is to educate the audience in light of the OSSE-related sections of the Forecast Improvement Act (H.R. 2413).

  5. Monte Carlo Simulation of Counting Experiments.

    ERIC Educational Resources Information Center

    Ogden, Philip M.

    A computer program to perform a Monte Carlo simulation of counting experiments was written. The program was based on a mathematical derivation which started with counts in a time interval. The time interval was subdivided to form a binomial distribution with no two counts in the same subinterval. Then the number of subintervals was extended to…

  6. ASPEN computer simulations of the mixed waste treatment project baseline flowsheet

    SciTech Connect

    Dietsche, L.J.; Upadhye, R.S.; Camp, D.W.; Pendergrass, J.A.; Borduin, L.C.; Thompson, T.K.

    1994-07-05

    The treatment and disposal of mixed waste (i.e., waste containing both hazardous and radioactive components) is a challenging waste- management problem of particular concern to Department of Energy (DOE) sites throughout the United States. Traditional technologies used for destroying hazardous wastes must be re- evaluated for their ability to handle mixed wastes, and, in some cases, new technologies must be developed. The Mixed Waste Treatment Project (MWTP), a collaborative effort between Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory, and Pacific Northwest Laboratory (PNL), was established by the DOE`s Waste Operations Program (EM-30) to develop and analyze alternative mixed waste treatment approaches. One of the MWTP`s initiatives, and the objective of this study, was to develop flowsheets for prototype, integrated, mixed-waste treatment facilities that can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modeling. The objectives of the flowsheet simulations are to compare process effectiveness and costs of alternative flowsheets and to determine if commercial process-simulation software could be used on the large, complex process of an integrated mixed waste processing facility. Flowsheet modeling is needed to evaluate many aspects of proposed flowsheet designs. A major advantage of modeling the complete flowsheet is the ability to define the internal recycle streams, thereby making it possible to evaluate the impact of one operation on the whole plant. Many effects that can be seen only in this way. Modeling also can be used to evaluate sensitivity and range of operating conditions, radioactive criticality, and relative costs of different flowsheet designs. Further, the modeled flowsheets must be easily modified so that one can examine how alternative technologies and varying feed streams affect the overall integrated process.

  7. Using syllable-timed speech to treat preschool children who stutter: a multiple baseline experiment.

    PubMed

    Trajkovski, Natasha; Andrews, Cheryl; Onslow, Mark; Packman, Ann; O'Brian, Sue; Menzies, Ross

    2009-03-01

    This report presents the results of an experimental investigation of the effects of a syllable-timed speech treatment on three stuttering preschool children. Syllable-timed speech involves speaking with minimal differentiation in linguistic stress across syllables. Three children were studied in a multiple baseline across participants design, with percent syllables stuttered (%SS) as the dependent variable. In the week following the initial clinic visit, each child decreased their beyond-clinic stuttering by 40%, 49% and 32%, respectively. These reductions are only evident in the time series after the introduction of the syllable-timed speech treatment procedure. Participants required a mean of six clinic visits, of approximately 30-60 min in duration, to reach and sustain a beyond-clinic %SS below 1.0. The results suggest that clinical trials of the treatment are warranted. The reader will be able to summarize, discuss and evaluate: (1) The nature, impact and treatment options available for early stuttering. (2) The syllable-timed speech treatment protocol administered. (3) The advantages of syllable-timed speech treatment for early stuttering. (4) The questions that further research needs to answer about the syllable-timed speech treatment.

  8. Collisionless Plasma Astrophysics Simulation Experiments using Lasers

    SciTech Connect

    Woolsey, N. C.; Ash, A. D.; Courtois, C.; Gregory, C. D.; Hall, I. M.; Howe, J.; Dendy, R. O.

    2006-04-07

    Laboratory experiment is an attractive method of exploring the plasma physics that may occur in solar and astrophysical shocks. An experiment enables repeated and detailed measurements of a plasma as the input conditions are adjusted. To form a scaled experiment of an astrophysical shock a plasma physics model of the shock is required, and the important dimensionless parameters identified and reproduced in the laboratory. A laboratory simulation of a young supernova remnant is described. The experiment uses the interaction of two millimetre-sized counter-streaming laser-produced plasmas placed in a strong transverse magnetic field to achieve this scaling. The collision-free dynamics of the two plasmas and their interaction are studied with and without the magnetic field through spatially and temporally resolved optical measurements. Laboratory astroplasma physics experiments using high-energy, high-power laser technology enables us to reproduce in the laboratory the conditions of temperature and pressure that are met in extreme stellar environments.

  9. Search for sterile neutrino mixing in the MINOS long baseline experiment

    SciTech Connect

    Adamson, P.; Andreopoulos, C.; Auty, D.J.; Ayres, D.S.; Backhouse, C.; Barnes Jr., P.D.; Barr, G.; Barrett, W.L.; Bishai, M.; Blake, A.; Bock, G.J.; /Fermilab /Fermilab

    2010-01-01

    A search for depletion of the combined flux of active neutrino species over a 735 km baseline is reported using neutral-current interaction data recorded by the MINOS detectors in the NuMI neutrino beam. Such a depletion is not expected according to conventional interpretations of neutrino oscillation data involving the three known neutrino flavors. A depletion would be a signature of oscillations or decay to postulated noninteracting sterile neutrinos, scenarios not ruled out by existing data. From an exposure of 3.18 x 10{sup 20} protons on target in which neutrinos of energies between {approx}500 MeV and 120 GeV are produced predominantly as {nu}{sub {mu}}, the visible energy spectrum of candidate neutral-current reactions in the MINOS far-detector is reconstructed. Comparison of this spectrum to that inferred from a similarly selected near-detector sample shows that of the portion of the {nu}{sub {mu}} flux observed to disappear in charged-current interaction data, the fraction that could be converting to a sterile state is less than 52% at 90% confidence level (C.L.). The hypothesis that active neutrinos mix with a single sterile neutrino via oscillations is tested by fitting the data to various models. In the particular four-neutrino models considered, the mixing angles {theta}{sub 24} and {theta}{sub 34} are constrained to be less than 11{sup o} and 56{sup o} at 90% C.L., respectively. The possibility that active neutrinos may decay to sterile neutrinos is also investigated. Pure neutrino decay without oscillations is ruled out at 5.4 standard deviations. For the scenario in which active neutrinos decay into sterile states concurrently with neutrino oscillations, a lower limit is established for the neutrino decay lifetime {tau}{sub 3}/m{sub 3} > 2.1 x 10{sup -12} s/eV at 90% C.L.

  10. Functional endemism: population connectivity, shifting baselines, and the scale of human experience

    PubMed Central

    Drew, Joshua; Kaufman, Les

    2013-01-01

    Quantifying population connectivity is important for visualizing the spatial and temporal scales that conservation measures act upon. Traditionally, migration based on genetic data has been reported in migrants per generation. However, the temporal scales over which this migration may occur do not necessarily accommodate the scales over which human perturbations occur, leaving the potential for a disconnect between population genetic data and conservation action based on those data. Here, we present a new metric called the “Rule of Memory”, which helps conservation practitioners to interpret “migrants per generation” in the context both of human modified ecosystems and the cultural memory of those doing the modification. Our rule states that clades should be considered functionally endemic regardless of their actual taxonomic designation if the migration between locations is insufficient to maintain a viable population over the timescales of one human generation (20 years). Since larger animals are more likely to be remembered, we quantify the relationship between migrants per human (N) and body mass of the organism in question (M) with the formula N = 10M−1. We then use the coral reef fish Pomacentrus moluccensis to demonstrate the taxonomic and spatial scales over which this rule can be applied. Going beyond minimum viable population literature, this metric assesses the probability that a clade's existence will be forgotten by people throughout its range during a period of extirpation. Because conservation plans are predicated on having well-established baselines, a loss of a species over the range of one human generation evokes the likelihood of that species no longer being recognized as a member of an ecosystem, and thus being excluded in restoration or conservation prioritization. [Correction added on 26 December 2012, after first online publication: this formula has been corrected to N=10M−1]. PMID:23467269

  11. Experiences using multigrid for geothermal simulation

    SciTech Connect

    Bullivant, D.P.; O`Sullivan, M.J.; Yang, Z.

    1995-03-01

    Experiences of applying multigrid to the calculation of natural states for geothermal simulations are discussed. The modelling of natural states was chosen for this study because they can take a long time to compute and the computation is often dominated by the development of phase change boundaries that take up a small region in the simulation. For the first part of this work a modified version of TOUGH was used for 2-D vertical problems. A {open_quotes}test-bed{close_quotes} program is now being used to investigate some of the problems encountered with implementing multigrid. This is ongoing work. To date, there have been some encouraging but not startling results.

  12. Titan's organic chemistry: Results of simulation experiments

    NASA Technical Reports Server (NTRS)

    Sagan, Carl; Thompson, W. Reid; Khare, Bishun N.

    1992-01-01

    Recent low pressure continuous low plasma discharge simulations of the auroral electron driven organic chemistry in Titan's mesosphere are reviewed. These simulations yielded results in good accord with Voyager observations of gas phase organic species. Optical constants of the brownish solid tholins produced in similar experiments are in good accord with Voyager observations of the Titan haze. Titan tholins are rich in prebiotic organic constituents; the Huygens entry probe may shed light on some of the processes that led to the origin of life on Earth.

  13. Titan's organic chemistry: Results of simulation experiments

    NASA Technical Reports Server (NTRS)

    Sagan, Carl; Thompson, W. Reid; Khare, Bishun N.

    1992-01-01

    Recent low pressure continuous low plasma discharge simulations of the auroral electron driven organic chemistry in Titan's mesosphere are reviewed. These simulations yielded results in good accord with Voyager observations of gas phase organic species. Optical constants of the brownish solid tholins produced in similar experiments are in good accord with Voyager observations of the Titan haze. Titan tholins are rich in prebiotic organic constituents; the Huygens entry probe may shed light on some of the processes that led to the origin of life on Earth.

  14. Photographic Emulsions in the OPERA Long Baseline Experiment Status and First Results

    NASA Astrophysics Data System (ADS)

    Meisel, Frank W.

    2010-04-01

    The OPERA experiment (Oscillation Project with Emulsion tRacking Apparatus) has been designed to confirm the neutrino oscillation hypothesis by direct observation of the tau neutrino appearance coming out of a (almost) pure muon neutrino beam. The beam is extracted from the SPS at CERN towards the Gran Sasso Underground Laboratory, the location of OPERA, 730km afar. In order to detect the leptonic tau decays, the vertex detector needs a spatial resolution of the order of micrometers. Nuclear emulsion films are the only detector materials capable of fulfilling this tight condition. In addition, emulsion scanning techniques have been significantly improved during the last recent neutrino experiments. This article is going to review the status of the detector, the neutrino beam properties, the first results from the 2008 run and the neutrino event analyses putting special emphasis on the emulsion detection technique.

  15. The NOvA Timing System: A system for synchronizing a long baseline neutrino experiment

    NASA Astrophysics Data System (ADS)

    Norman, A.; Kwarciany, R.; Deuerling, G.; Wilcer, N.

    2012-12-01

    The NOvA experiment is designed to measure key parameters in neutrino physics related to the neutrino mass hierarchy and the asymmetry between matter and anti-matter. To make these measurements the NOvA experiment must correlate the extraction of beam to the NuMI target with individual hits in both a near detector and a far detector located 810 km from Fermilab. Precisely correlating hits across these detectors and reconstructing particle trajectories require that all of the readout electronics be precisely synchronized to an absolute wall time with a channel to channel variation less than 15.6 ns. The NOvA Timing Distribution System accomplishes this through an integration of commercial GPS receiver technology and custom electronics. This paper describes the timing system, its component hardware and the synchronization method that is employed by it.

  16. Search for Sterile Neutrinos with the MINOS Long-Baseline Experiment

    SciTech Connect

    Timmons, Ashley Michael

    2016-01-01

    This thesis will present a search for sterile neutrinos using data taken with the MINOS experiment between 2005 and 2012. MINOS is a two-detector on-axis experiment based at Fermilab. The NuMI neutrino beam encounters the MINOS Near Detector 1km downstream of the neutrino-production target before traveling a further 734km through the Earth's crust, to reach the Far Detector located at the Soudan Underground Laboratory in Northern Minnesota. By searching for oscillations driven by a large mass splitting, MINOS is sensitive to the existence of sterile neutrinos through looking for any energy-dependent perturbations using a charged-current sample, as well as looking at any relative deficit in neutral current events between the Far and Near Detectors. This thesis will discuss the novel analysis that enabled a search for sterile neutrinos covering five orders of magnitude in the mass splitting and setting a limit in previously unexplored regions of the parameter space $\\left\\{\\Delta m^{2}_{41},\\sin^2\\theta_{24}\\right\\}$, where a 3+1-flavour phenomenological model was used to extract parameter limits. The results presented in this thesis are sensitive to the sterile neutrino parameter space suggested by the LSND and MiniBooNE experiments.

  17. Numerical simulation of the Beta II experiment

    SciTech Connect

    Shumaker, D.E.; Boyd, J.K.; McNamara, B.; Turner, W.C.

    1981-10-01

    The transport code FRT which is a 1-1/2-D transport-equilibrium code for an axisymmetric plasma was used to simulate the decay of the plasma and magnetic fields of the Beta II experiment. A comparison is made between the experimentally determined decay times for the magnetic fields and particle confinement times and the computed decay times. It is found that 1% oxygen impurity is enough to clamp the electron temperature below the radiation barrier, which is in agreement with the experiment.

  18. Polyurethane Foam Impact Experiments and Simulations

    SciTech Connect

    Chhabildas, L.C.; Kipp, M.E.; Reinhart, W.D.; Wong, M.K.

    1999-06-17

    Uniaxial strain impact experiments have been performed to obtain shock compression and release response of a 0.22 g/cm{sup 3} polyurethane foam in a configuration where the foam impacts a thin target witness plate. Wave profiles from a suite of ten experiments have been obtained, where shock amplitudes range from 40 to 500 MPa. A traditional p-{alpha} porous material model generally captures the material response. A fully three-dimensional explicit representation of the heterogeneous foam structure modeled with numerical simulations recovers some of the high frequency aspects of the particle velocity records.

  19. Kinetic simulation of a plasma collision experiment

    NASA Astrophysics Data System (ADS)

    Larroche, Olivier

    1993-08-01

    The ionic Fokker-Planck code which was written for describing plasma shock wave fronts [M. Casanova et al. Phys. Rev. Lett. 67, 2143 (1991)] is applied to model the collision of two plasmas in plane geometry. Improvements brought to the code for that purpose are described. The initial phase of the experiment during which the plasmas interpenetrate is accounted for by a simple fluid model, which yields qualitative insight into the phenomena at play as well as an initial condition to start the kinetic simulation. The kinetic results obtained in the stagnation and thermalization phases are discussed with respect to a specific laser-produced plasma collision experiment, as well as to existing fluid and kinetic (``particle-in-cell'') simulations.

  20. Modeling external events in the three-level analysis of multiple-baseline across-participants designs: a simulation study.

    PubMed

    Moeyaert, Mariola; Ugille, Maaike; Ferron, John M; Beretvas, S Natasha; Van den Noortgate, Wim

    2013-06-01

    In this study, we focus on a three-level meta-analysis for combining data from studies using multiple-baseline across-participants designs. A complicating factor in such designs is that results might be biased if the dependent variable is affected by not explicitly modeled external events, such as the illness of a teacher, an exciting class activity, or the presence of a foreign observer. In multiple-baseline designs, external effects can become apparent if they simultaneously have an effect on the outcome score(s) of the participants within a study. This study presents a method for adjusting the three-level model to external events and evaluates the appropriateness of the modified model. Therefore, we use a simulation study, and we illustrate the new approach with real data sets. The results indicate that ignoring an external event effect results in biased estimates of the treatment effects, especially when there is only a small number of studies and measurement occasions involved. The mean squared error, as well as the standard error and coverage proportion of the effect estimates, is improved with the modified model. Moreover, the adjusted model results in less biased variance estimates. If there is no external event effect, we find no differences in results between the modified and unmodified models.

  1. Polar-direct-drive simulations and experiments

    SciTech Connect

    Marozas, J.A.; Marshall, F.J.; Craxton, R.S.; Igumenshchev, I.V.; Skupsky, S.; Bonino, M.J.; Collins, T.J.B.; Epstein, R.; Glebov, V.Yu.; Jacobs-Perkins, D.; Knauer, J.P.; McCrory, R.L.; McKenty, P.W.; Meyerhofer, D.D.; Noyes, S.G.; Radha, P.B.; Sangster, T.C.; Seka, W.; Smalyuk, V.A.

    2006-05-15

    Polar direct drive (PDD) [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] will allow direct-drive ignition experiments on the National Ignition Facility (NIF) [J. Paisner et al., Laser Focus World 30, 75 (1994)] as it is configured for x-ray drive. Optimal drive uniformity is obtained via a combination of beam repointing, pulse shapes, spot shapes, and/or target design. This article describes progress in the development of standard and 'Saturn' [R. S. Craxton and D. W. Jacobs-Perkins, Phys. Rev. Lett. 94, 0952002 (2005)] PDD target designs. Initial evaluation of experiments on the OMEGA Laser System [T. R. Boehly et al., Rev. Sci. Instrum. 66, 508 (1995)] and simulations were carried out with the two-dimensional hydrodynamics code SAGE [R. S. Craxton et al., Phys. Plasmas 12, 056304 (2005)]. This article adds to this body of work by including fusion particle production and transport as well as radiation transport within the two-dimensional DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] hydrodynamics simulations used to model experiments. Forty OMEGA beams arranged in six rings to emulate the NIF x-ray-drive configuration are used to perform direct-drive implosions of CH shells filled with D{sub 2} gas. Target performance was diagnosed with framed x-ray backlighting and by the measured fusion yield. Saturn target experiments have resulted in {approx}75% of the yield from energy-equivalent, symmetrically irradiated implosions. The results of the two-dimensional PDD simulations performed with DRACO are in good agreement with experimental x-ray radiographs. DRACO is being used to further optimize standard PDD designs. In addition, DRACO simulations of NIF-scale PDD designs show ignition with a gain of 20 and the development of a 40 {mu}m radius, 10 keV region with a neutron-averaged {rho}r of 1270 mg/cm{sup 2} near stagnation.

  2. An Introduction to Observing System Simulation Experiments

    NASA Technical Reports Server (NTRS)

    Prive, Nikki C.

    2017-01-01

    Observing System Simulation Experiments (OSSEs) are used to estimate the potential impact of proposed new instruments and data on numerical weather prediction. OSSEs can also be used to help design new observing platforms and to investigate the behavior of data assimilation systems. A basic overview of how to design and perform an OSSE will be given, as well as best practices and pitfalls. Some examples using the OSSE framework developed at the NASA Global Modeling and Assimilation Office will be shown.

  3. Applicability of second-order expansion in s13 to explore δCP in small and medium baseline ν experiments

    NASA Astrophysics Data System (ADS)

    Singh, Mandip

    2016-03-01

    The series expansion of neutrino evolution matrix “S”, up to first-order in small reactor mixing angle θ13 is very useful formalism to study experiments quantitatively. The formalism has been used especially to investigate CP-violating phase δCP. In order to perform a broad investigation for the possible measurement of δCP phase, we will study small baseline experiments: Chooz (L = 1.03Km), T2K (L = 295Km) and ESS (L = 500Km), medium baseline experiment: NOνA (L = 810Km) and long baseline experiment: LBNE (L = 1300Km).

  4. Hydrodynamic Simulations of Gaseous Argon Shock Experiments

    NASA Astrophysics Data System (ADS)

    Garcia, Daniel; Dattelbaum, Dana; Goodwin, Peter; Morris, John; Sheffield, Stephen; Burkett, Michael

    2015-06-01

    The lack of published Argon gas shock data motivated an evaluation of the Argon Equation of State (EOS) in gas phase initial density regimes never before reached. In particular, these regimes include initial pressures in the range of 200-500 psi (0.025 - 0.056 g/cc) and initial shock velocities around 0.2 cm/ μs. The objective of the numerical evaluation was to develop a physical understanding of the EOS behavior of shocked and subsequently multiply re-shocked Argon gas initially pressurized to 200-500 psi through Pagosa numerical hydrodynamic simulations utilizing the SESAME equation of state. Pagosa is a Los Alamos National Laboratory 2-D and 3-D Eulerian hydrocode capable of modeling high velocity compressible flow with multiple materials. The approach involved the use of gas gun experiments to evaluate the shock and multiple re-shock behavior of pressurized Argon gas to validate Pagosa simulations and the SESAME EOS. Additionally, the diagnostic capability within the experiments allowed for the EOS to be fully constrained with measured shock velocity, particle velocity and temperature. The simulations demonstrate excellent agreement with the experiments in the shock velocity/particle velocity space, but note unanticipated differences in the ionization front temperatures.

  5. Simulations and Experiments in Astronomy and Physics

    NASA Astrophysics Data System (ADS)

    Maloney, F. P.; Maurone, P. A.; Dewarf, L. E.

    1998-12-01

    There are new approaches to teaching astronomy and physics in the laboratory setting, involving the use of computers as tools to simulate events and concepts which can be illuminated in no other reasonable way. With the computer, it is possible to travel back in time to replicate the sky as Galileo saw it. Astronomical phenomena which reveal themselves only after centuries of real time may be compressed in the computer to a simulation of several minutes. Observations simulated on the computer do not suffer from the vagaries of weather, fixed time or geographic position, or non-repeatability. In physics, the computer allows us to secure data for experiments which, by their nature, may not be amenable to human interaction. These could include experiments with very fast or very slow timescales, large number of data samples, complex or tedious manipulation of the data which hides the fundamental nature of the experiment, or data sampling which would need a specialized probe, such as for acid rain. This innovation has become possible only recently, due to the availability and affordability of sophisticated computer hardware and software. We have developed a laboratory experience for non-scientists who need an introductory course in astronomy or physics. Our approach makes extensive use of computers in this laboratory. Using commercially available software, the students use the computer as a time machine and a space craft to explore and rediscover fundamental science. The physics experiments are classical in nature, and the computer acts as a data collector and presenter, freeing the student from the tedium of repetitive data gathering and replotting. In this way, the student is encouraged to explore, to try new things, to refine the measurements, and to discover the principles underlying the observed phenomena.

  6. Search for sub-eV sterile neutrinos in the precision multiple baselines reactor antineutrino oscillation experiments

    NASA Astrophysics Data System (ADS)

    Luo, Shu

    2015-10-01

    According to different effects on neutrino oscillations, the unitarity violation in the MNSP matrix can be classified into the direct unitarity violation and the indirect unitarity violation which are induced by the existence of the light and the heavy sterile neutrinos respectively. Of which sub-eV sterile neutrinos are of most interesting. We study in this paper the possibility of searching for sub-eV sterile neutrinos in the precision reactor antineutrino oscillation experiments with three different baselines at around 500 m, 2 km and 60 km. We find that the antineutrino survival probabilities obtained in the reactor experiments are sensitive only to the direct unitarity violation and offer very concentrated sensitivity to the two parameters θ14 and Δ m412. If such light sterile neutrinos do exist, the active-sterile mixing angle θ14 could be acquired by the combined rate analysis at all the three baselines and the mass-squared difference Δm412 could be obtained by taking the Fourier transformation to the L / E spectrum. Of course, for such measurements to succeed, both high energy resolution and large statistics are essentially important.

  7. Probing CP violation with non-unitary mixing in long-baseline neutrino oscillation experiments: DUNE as a case study

    NASA Astrophysics Data System (ADS)

    Escrihuela, F. J.; Forero, D. V.; Miranda, O. G.; Tórtola, M.; Valle, J. W. F.

    2017-09-01

    When neutrino masses arise from the exchange of neutral heavy leptons, as in most seesaw schemes, the effective lepton mixing matrix N describing neutrino propagation is non-unitary, hence neutrinos are not exactly orthonormal. New CP violation phases appear in N that could be confused with the standard phase {δ }{CP} characterizing the three neutrino paradigm. We study the potential of the long-baseline neutrino experiment DUNE in probing CP violation induced by the standard CP phase in the presence of non-unitarity. In order to accomplish this we develop our previous formalism, so as to take into account the neutrino interactions with the medium, important in long baseline experiments such as DUNE. We find that the expected CP sensitivity of DUNE is somewhat degraded with respect to that characterizing the standard unitary case. However the effect is weaker than might have been expected thanks mainly to the wide neutrino beam. We also investigate the sensitivity of DUNE to the parameters characterizing non-unitarity. In this case we find that there is no improvement expected with respect to the current situation, unless the near detector setup is revamped.

  8. Miller experiments in atomistic computer simulations

    PubMed Central

    Saitta, Antonino Marco; Saija, Franz

    2014-01-01

    The celebrated Miller experiments reported on the spontaneous formation of amino acids from a mixture of simple molecules reacting under an electric discharge, giving birth to the research field of prebiotic chemistry. However, the chemical reactions involved in those experiments have never been studied at the atomic level. Here we report on, to our knowledge, the first ab initio computer simulations of Miller-like experiments in the condensed phase. Our study, based on the recent method of treatment of aqueous systems under electric fields and on metadynamics analysis of chemical reactions, shows that glycine spontaneously forms from mixtures of simple molecules once an electric field is switched on and identifies formic acid and formamide as key intermediate products of the early steps of the Miller reactions, and the crucible of formation of complex biological molecules. PMID:25201948

  9. PHITS simulations of the Matroshka experiment

    NASA Astrophysics Data System (ADS)

    Gustafsson, Katarina; Sihver, Lembit; Mancusi, Davide; Sato, Tatsuhiko

    In order to design a more secure space exploration, radiation exposure estimations are necessary; the radiation environment in space is very different from the one on Earth and it is harmful for humans and for electronic equipments. The threat origins from two sources: Galactic Cosmic Rays and Solar Particle Events. It is important to understand what happens when these particles strike matter such as space vehicle walls, human organs and electronics. We are therefore developing a tool able to estimate the radiation exposure to both humans and electronics. The tool will be based on PHITS, the Particle and Heavy-Ion Transport code System, a three dimensional Monte Carlo code which can calculate interactions and transport of particles and heavy ions in matter. PHITS is developed by a collaboration between RIST (Research Organization for Information Science & Technology), JAEA (Japan Atomic Energy Agency), KEK (High Energy Accelerator Research Organization), Japan and Chalmers University of Technology, Sweden. A method for benchmarking and developing the code is to simulate experiments performed in space or on Earth. We have carried out simulations of the Matroshka experiment which focus on determining the radiation load on astronauts inside and outside the International Space Station by using a torso of a tissue equivalent human phantom, filled with active and passive detectors located in the positions of critical tissues and organs. We will present status and results of our simulations.

  10. Direct Simulation of a Solidification Benchmark Experiment

    NASA Astrophysics Data System (ADS)

    Carozzani, Tommy; Gandin, Charles-André; Digonnet, Hugues; Bellet, Michel; Zaidat, Kader; Fautrelle, Yves

    2013-02-01

    A solidification benchmark experiment is simulated using a three-dimensional cellular automaton—finite element solidification model. The experiment consists of a rectangular cavity containing a Sn-3 wt pct Pb alloy. The alloy is first melted and then solidified in the cavity. A dense array of thermocouples permits monitoring of temperatures in the cavity and in the heat exchangers surrounding the cavity. After solidification, the grain structure is revealed by metallography. X-ray radiography and inductively coupled plasma spectrometry are also conducted to access a distribution map of Pb, or macrosegregation map. The solidification model consists of solutions for heat, solute mass, and momentum conservations using the finite element method. It is coupled with a description of the development of grain structure using the cellular automaton method. A careful and direct comparison with experimental results is possible thanks to boundary conditions deduced from the temperature measurements, as well as a careful choice of the values of the material properties for simulation. Results show that the temperature maps and the macrosegregation map can only be approached with a three-dimensional simulation that includes the description of the grain structure.

  11. Computer simulations of WIGWAM underwater experiment

    SciTech Connect

    Kamegai, Minao; White, J.W.

    1993-11-01

    We performed computer simulations of the WIGWAM underwater experiment with a 2-D hydro-code, CALE. First, we calculated the bubble pulse and the signal strength at the closest gauge in one-dimensional geometry. The calculation shows excellent agreement with the measured data. Next, we made two-dimensional simulations of WIGWAM applying the gravity over-pressure, and calculated the signals at three selected gauge locations where measurements were recorded. The computed peak pressures at those gauge locations come well within the 15% experimental error bars. The signal at the farthest gauge is of the order of 200 bars. This is significant, because at this pressure the CALE output can be linked to a hydro-acoustics computer program, NPE Code (Nonlinear Progressive Wave-equation Code), to analyze the long distance propagation of acoustical signals from the underwater explosions on a global scale.

  12. Simulation studies for the PANDA experiment

    SciTech Connect

    Kopf, B.

    2005-10-26

    One main component of the planned Facility for Antiproton and Ion Research (FAIR) is the High Energy Storage Ring (HESR) at GSI, Darmstadt, which will provide cooled antiprotons with momenta between 1.5 and 15 GeV/c. The PANDA experiment will investigate p-barannihilations with internal hydrogen and nuclear targets. Due to the planned extensive physics program a multipurpose detector with nearly complete solid angle coverage, proper particle identification over a large momentum range, and high resolution calorimetry for neutral particles is required. For the optimization of the detector design simulation studies of several benchmark channels are in progress which are covering the most relevant physics topics. Some important simulation results are discussed here.

  13. Data Simulation for 21 cm Cosmology Experiments

    NASA Astrophysics Data System (ADS)

    Pober, Jonathan

    2017-01-01

    21 cm cosmologists seek a measurement of the hyperfine line of neutral hydrogen from very high redshifts. While this signal has the potential to provide an unprecedented view into the early universe, it is also buried under exceedingly bright foreground emission. Over the last several years, 21 cm cosmology research has led to an improved understanding of how low frequency radio interferometers will affect the separation of cosmological signal from foregrounds. This talk will describe new efforts to incorporate this understanding into simulations of the most realistic data sets for the Precision Array for Probing the Epoch of Reionization (PAPER), the Murchison Widefield Array (MWA), and the Hydrogen Epoch of Reionization Array (HERA). These high fidelity simulations are essential for robust algorithm design and validation of early results from these experiments.

  14. 33alloy: comparison between experiment and simulation

    SciTech Connect

    Kramer, M J; Mendelev, M I; Asta, M

    2014-04-22

    We report data on the structure of liquid Al and an Al67Mg33 alloy obtained from state-of-the-art X-ray diffraction experiments and ab initio molecular dynamics (AIMD) simulations. To facilitate a direct comparison between these data, we develop a method to elongate the AIMD pair correlation function in order to obtain reliable AIMD structure factors. The comparison reveals an appreciable level of discrepancy between experimental and AIMD liquid structures, with the latter being consistently more ordered than the former at the same temperature. The discrepancy noted in this study is estimated to have significant implications for simulation-based calculations of liquid transport properties and solid–liquid interface kinetic properties.

  15. Computer simulations of the noise injection experiment

    SciTech Connect

    Wang, P.W.; Hale, J.R.; Schultz, J.H.; Pillsbury, R.D. Jr.

    1995-12-31

    An objective of the Noise Injection Experiment (NIE) is to calibrate the numerical methods used to estimate the noise level in the proposed internal, cowound voltage sensors to be used in the superconducting magnets, such as those in ITER and TPX. A time-varying magnetic field is applied to the sample windings and the pick-up signals in the parallel and helical sensors (some are internally terminated) are measured. A computer model is developed to predict the results, and the measurements are compared with the computer simulations.

  16. Learning in innovation networks: Some simulation experiments

    NASA Astrophysics Data System (ADS)

    Gilbert, Nigel; Ahrweiler, Petra; Pyka, Andreas

    2007-05-01

    According to the organizational learning literature, the greatest competitive advantage a firm has is its ability to learn. In this paper, a framework for modeling learning competence in firms is presented to improve the understanding of managing innovation. Firms with different knowledge stocks attempt to improve their economic performance by engaging in radical or incremental innovation activities and through partnerships and networking with other firms. In trying to vary and/or to stabilize their knowledge stocks by organizational learning, they attempt to adapt to environmental requirements while the market strongly selects on the results. The simulation experiments show the impact of different learning activities, underlining the importance of innovation and learning.

  17. ALEGRA -- code validation: Experiments and simulations

    SciTech Connect

    Chhabildas, L.C.; Konrad, C.H.; Mosher, D.A.; Reinhart, W.D; Duggins, B.D.; Rodeman, R.; Trucano, T.G.; Summers, R.M.; Peery, J.S.

    1998-03-16

    In this study, the authors are providing an experimental test bed for validating features of the ALEGRA code over a broad range of strain rates with overlapping diagnostics that encompass the multiple responses. A unique feature of the Arbitrary Lagrangian Eulerian Grid for Research Applications (ALEGRA) code is that it allows simultaneous computational treatment, within one code, of a wide range of strain-rates varying from hydrodynamic to structural conditions. This range encompasses strain rates characteristic of shock-wave propagation (10{sup 7}/s) and those characteristic of structural response (10{sup 2}/s). Most previous code validation experimental studies, however, have been restricted to simulating or investigating a single strain-rate regime. What is new and different in this investigation is that the authors have performed well-instrumented experiments which capture features relevant to both hydrodynamic and structural response in a single experiment. Aluminum was chosen for use in this study because it is a well characterized material--its EOS and constitutive material properties are well defined over a wide range of loading rates. The current experiments span strain rate regimes of over 10{sup 7}/s to less than 10{sup 2}/s in a single experiment. The input conditions are extremely well defined. Velocity interferometers are used to record the high strain-rate response, while low strain rate data were collected using strain gauges.

  18. NASCAP simulation of PIX 2 experiments

    NASA Technical Reports Server (NTRS)

    Roche, J. C.; Mandell, M. J.

    1985-01-01

    The latest version of the NASCAP/LEO digital computer code used to simulate the PIX 2 experiment is discussed. NASCAP is a finite-element code and previous versions were restricted to a single fixed mesh size. As a consequence the resolution was dictated by the largest physical dimension to be modeled. The latest version of NASCAP/LEO can subdivide selected regions. This permitted the modeling of the overall Delta launch vehicle in the primary computational grid at a coarse resolution, with subdivided regions at finer resolution being used to pick up the details of the experiment module configuration. Langmuir probe data from the flight were used to estimate the space plasma density and temperature and the Delta ground potential relative to the space plasma. This information is needed for input to NASCAP. Because of the uncertainty or variability in the values of these parameters, it was necessary to explore a range around the nominal value in order to determine the variation in current collection. The flight data from PIX 2 were also compared with the results of the NASCAP simulation.

  19. Observation simulation experiments with regional prediction models

    NASA Technical Reports Server (NTRS)

    Diak, George; Perkey, Donald J.; Kalb, Michael; Robertson, Franklin R.; Jedlovec, Gary

    1990-01-01

    Research efforts in FY 1990 included studies employing regional scale numerical models as aids in evaluating potential contributions of specific satellite observing systems (current and future) to numerical prediction. One study involves Observing System Simulation Experiments (OSSEs) which mimic operational initialization/forecast cycles but incorporate simulated Advanced Microwave Sounding Unit (AMSU) radiances as input data. The objective of this and related studies is to anticipate the potential value of data from these satellite systems, and develop applications of remotely sensed data for the benefit of short range forecasts. Techniques are also being used that rely on numerical model-based synthetic satellite radiances to interpret the information content of various types of remotely sensed image and sounding products. With this approach, evolution of simulated channel radiance image features can be directly interpreted in terms of the atmospheric dynamical processes depicted by a model. Progress is being made in a study using the internal consistency of a regional prediction model to simplify the assessment of forced diabatic heating and moisture initialization in reducing model spinup times. Techniques for model initialization are being examined, with focus on implications for potential applications of remote microwave observations, including AMSU and Special Sensor Microwave Imager (SSM/I), in shortening model spinup time for regional prediction.

  20. Chaos in plasma simulation and experiment

    SciTech Connect

    Watts, C.; Newman, D.E.; Sprott, J.C.

    1993-09-01

    We investigate the possibility that chaos and simple determinism are governing the dynamics of reversed field pinch (RFP) plasmas using data from both numerical simulations and experiment. A large repertoire of nonlinear analysis techniques is used to identify low dimensional chaos. These tools include phase portraits and Poincard sections, correlation dimension, the spectrum of Lyapunov exponents and short term predictability. In addition, nonlinear noise reduction techniques are applied to the experimental data in an attempt to extract any underlying deterministic dynamics. Two model systems are used to simulate the plasma dynamics. These are -the DEBS code, which models global RFP dynamics, and the dissipative trapped electron mode (DTEM) model, which models drift wave turbulence. Data from both simulations show strong indications of low,dimensional chaos and simple determinism. Experimental data were obtained from the Madison Symmetric Torus RFP and consist of a wide array of both global and local diagnostic signals. None of the signals shows any indication of low dimensional chaos or other simple determinism. Moreover, most of the analysis tools indicate the experimental system is very high dimensional with properties similar to noise. Nonlinear noise reduction is unsuccessful at extracting an underlying deterministic system.

  1. A simulation of data acquisition system for SSC experiments

    SciTech Connect

    Watase, Y.; Ikeda, H.

    1989-04-01

    A simulation on some parts of the data acquisition system was performed using a general purpose simulation language GPSS. Several results of the simulation are discussed for the data acquisition system for the SSC experiment.

  2. [Simulation in medicine: first experiences under hemodialysis].

    PubMed

    Duranti, Ennio; Calzeroni, Gino; Venneri, Francesco; Marziali, Mauro

    2013-01-01

    Education and practical training in medicine is neglected and pass directly from theory to do on the field, while also each task requires the acquisition of health behaviors that are aware and accountable to the outreach. In hemodialysis is necessary to create synergies and partnerships between different cooperating figures. Addressing organizational and legal protection of the professionals (Clinical Risk). Acquiring operational capabilities of team work. Managing the team roles and functions.It is necessary then to acquire a modern methodology where the simulation represents the main tool, "the mistake" need to "learn" and the acquisition of "awareness" about event handling (in this case on Hemodialysis), in the context of clinical scenarios absolutely realistic.The methodology is based on simulated tasks using past experience as a business tool and innovative research. Debriefing and discussion with those involved and finally debrief collegiate looking for active/latent errors and use of international guidelines. Use of indicators to measure and review of performance during the various events and proactively promoting the reduction of the error.Among the types of participants was clear the minor presence of doctors of hemodialysis, probably for the wrong feeling of being checked and then judged in carrying out of actions made complex by urgency. In addition participating physicians have all stressed the usefulness of simulations of unusual events within the Hemodialysis treatment, but that if not solved can lead to death of the patient.Simulation under hemodialysis, although its first steps, appears to be an effective methodology able to stimulate self-criticism of the operators, but still with hesitations and fears above all by the nephrologists timorous of being judged more on technical skills than on organizational skills and leadership.

  3. Assessing the implications of baseline climate uncertainty on simulated water yield within the Himalayan Beas river basin in NW India

    NASA Astrophysics Data System (ADS)

    Holman, I.; Remesan, R.; Adeloye, A.; Ojha, C. S.

    2013-12-01

    baseline hydrological model performance with, for example, calibration Nash-Sutcliffe Efficiencies ranging from 0.56 to 0.68 across the precipitation datasets (using CFSR data to derive evapotranspiration) for the river Beas. To evaluate the potential impact of such uncertainty on assessments of future water yield, we further describe the application of a scenario-neutral modelling framework using IPPC AR4 ranges of temperature and precipitation changes to the baseline datasets to assess the differences in their response surfaces. The results show that the uncertainty in the driving hydroclimatological variables, associated with the choice of underlying observational dataset and the choice of evopo-transpiration method, translates into significant temporal and spatial uncertainty in simulated baseline and future water yield with significant implications for our ability to project changes in the water cycle in such sensitive regions.

  4. Simulation of a complete inelastic neutron scattering experiment

    NASA Astrophysics Data System (ADS)

    Edwards, H.; Lefmann, K.; Lake, B.; Nielsen, K.; Skaarup, P.

    A simulation of an inelastic neutron scattering experiment on the high-temperature superconductor La2-xSrxCuO4 is presented. The complete experiment, including sample, is simulated using an interface between the experiment control program and the simulation software package (McStas) and is compared with the experimental data. Simulating the entire experiment is an attractive alternative to the usual method of convoluting the model cross section with the resolution function, especially if the resolution function is nontrivial.

  5. Simulation and Reconstruction for the OLIVIA Experiment

    NASA Astrophysics Data System (ADS)

    Borucki, Timothy; Olivia Collaboration

    2017-01-01

    OLIVIA is an experiment that will provide a sensitive test of the weak interaction. The idea is to analyze Li-8 beta decay, followed by the double-alpha decay of the Be-8 daughter, using a gas-based Time Projection Chamber (TPC). Specifically, precision kinematic measurements of the 2 MeV alphas allow us to probe the V-A nature of the weak interaction. Alphas emitted in the TPC produce trails of ionization, which are drifted down through the detector to an amplification plane. The amplified track signals are then photographed and read out in time to provide a three-dimensional picture of the Li-8 decay event. Along with presenting the status and outlook for the OLIVIA project, I will discuss my work on simulating and reconstructing double-alpha waveforms from the TPC's amplification plane. This work is essential for achieving excellent alpha energy resolution, which will ultimately set OLIVIA's sensitivity to new physics.

  6. Braiding DNA: experiments, simulations, and models.

    PubMed

    Charvin, G; Vologodskii, A; Bensimon, D; Croquette, V

    2005-06-01

    DNA encounters topological problems in vivo because of its extended double-helical structure. As a consequence, the semiconservative mechanism of DNA replication leads to the formation of DNA braids or catenanes, which have to be removed for the completion of cell division. To get a better understanding of these structures, we have studied the elastic behavior of two braided nicked DNA molecules using a magnetic trap apparatus. The experimental data let us identify and characterize three regimes of braiding: a slightly twisted regime before the formation of the first crossing, followed by genuine braids which, at large braiding number, buckle to form plectonemes. Two different approaches support and quantify this characterization of the data. First, Monte Carlo (MC) simulations of braided DNAs yield a full description of the molecules' behavior and their buckling transition. Second, modeling the braids as a twisted swing provides a good approximation of the elastic response of the molecules as they are intertwined. Comparisons of the experiments and the MC simulations with this analytical model allow for a measurement of the diameter of the braids and its dependence upon entropic and electrostatic repulsive interactions. The MC simulations allow for an estimate of the effective torsional constant of the braids (at a stretching force F = 2 pN): C(b) approximately 48 nm (as compared with C approximately 100 nm for a single unnicked DNA). Finally, at low salt concentrations and for sufficiently large number of braids, the diameter of the braided molecules is observed to collapse to that of double-stranded DNA. We suggest that this collapse is due to the partial melting and fraying of the two nicked molecules and the subsequent right- or left-handed intertwining of the stretched single strands.

  7. KULL Simulations of OMEGA Radiation Flow Experiments

    NASA Astrophysics Data System (ADS)

    Kallman, J.; MacLaren, S.; Baker, K.; Brunner, T.; Lewis, K.; Zika, M.

    2013-10-01

    The problem of radiation flow in a right circular cylinder is of interest for the verification and validation of radiation codes since the flow is analytically analogous to diffusive free molecular flow in a similar geometry. Experiments were conducted on the OMEGA laser utilizing a low-density heated-cylindrical-wall target. The targets consisted of a 1.6 mm diameter gold hohlraum containing an on-axis 700 μm diameter SiO2 cylinder inside an 80 μm thick Ta2O5 aerogel tube. The FY13 targets also feature ``light-pipe'' diagnostics to measure the progression of the radiation front inside the foam. Simulations were run with the KULL multi-physics code, employing a new laser ray-tracing package. Comparisons of synthetic diagnostics derived from code results to x-ray measurements of drive temperature and heat front propagation provide a methodology to constrain simulation models. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. NDCX-II target experiments and simulations

    DOE PAGES

    Barnard, J. J.; More, R. M.; Terry, M.; ...

    2013-06-13

    The ion accelerator NDCX-II is undergoing commissioning at Lawrence Berkeley National Laboratory (LBNL). Its principal mission is to explore ion-driven High Energy Density Physics (HEDP) relevant to Inertial Fusion Energy (IFE) especially in the Warm Dense Matter (WDM) regime. We have carried out hydrodynamic simulations of beam-heated targets for parameters expected for the initial configuration of NDCX-II. For metal foils of order one micron thick (thin targets), the beam is predicted to heat the target in a timescale comparable to the hydrodynamic expansion time for experiments that infer material properties from measurements of the resulting rarefaction wave. We have alsomore » carried out hydrodynamic simulations of beam heating of metallic foam targets several tens of microns thick (thick targets) in which the ion range is shorter than the areal density of the material. In this case shock waves will form and we derive simple scaling laws for the efficiency of conversion of ion energy into kinetic energy of fluid flow. Geometries with a tamping layer may also be used to study the merging of a tamper shock with the end-of-range shock. As a result, this process can occur in tamped, direct drive IFE targets.« less

  9. NDCX-II target experiments and simulations

    SciTech Connect

    Barnard, J. J.; More, R. M.; Terry, M.; Friedman, A.; Henestroza, E.; Koniges, A.; Kwan, J. W.; Ng, A.; Ni, P. A.; Liu, W.; Logan, B. G.; Startsev, E.; Yuen, A.

    2013-06-13

    The ion accelerator NDCX-II is undergoing commissioning at Lawrence Berkeley National Laboratory (LBNL). Its principal mission is to explore ion-driven High Energy Density Physics (HEDP) relevant to Inertial Fusion Energy (IFE) especially in the Warm Dense Matter (WDM) regime. We have carried out hydrodynamic simulations of beam-heated targets for parameters expected for the initial configuration of NDCX-II. For metal foils of order one micron thick (thin targets), the beam is predicted to heat the target in a timescale comparable to the hydrodynamic expansion time for experiments that infer material properties from measurements of the resulting rarefaction wave. We have also carried out hydrodynamic simulations of beam heating of metallic foam targets several tens of microns thick (thick targets) in which the ion range is shorter than the areal density of the material. In this case shock waves will form and we derive simple scaling laws for the efficiency of conversion of ion energy into kinetic energy of fluid flow. Geometries with a tamping layer may also be used to study the merging of a tamper shock with the end-of-range shock. As a result, this process can occur in tamped, direct drive IFE targets.

  10. NDCX-II target experiments and simulations

    NASA Astrophysics Data System (ADS)

    Barnard, J. J.; More, R. M.; Terry, M.; Friedman, A.; Henestroza, E.; Koniges, A.; Kwan, J. W.; Ng, A.; Ni, P. A.; Liu, W.; Logan, B. G.; Startsev, E.; Yuen, A.

    2014-01-01

    The ion accelerator NDCX-II is undergoing commissioning at Lawrence Berkeley National Laboratory (LBNL). Its principal mission is to explore ion-driven High Energy Density Physics (HEDP) relevant to Inertial Fusion Energy (IFE) especially in the Warm Dense Matter (WDM) regime. We have carried out hydrodynamic simulations of beam-heated targets for parameters expected for the initial configuration of NDCX-II. For metal foils of order one micron thick (thin targets), the beam is predicted to heat the target in a timescale comparable to the hydrodynamic expansion time for experiments that infer material properties from measurements of the resulting rarefaction wave. We have also carried out hydrodynamic simulations of beam heating of metallic foam targets several tens of microns thick (thick targets) in which the ion range is shorter than the areal density of the material. In this case shock waves will form and we derive simple scaling laws for the efficiency of conversion of ion energy into kinetic energy of fluid flow. Geometries with a tamping layer may also be used to study the merging of a tamper shock with the end-of-range shock. This process can occur in tamped, direct drive IFE targets.

  11. KULL Simulations of OMEGA Radiation Flow Experiments

    NASA Astrophysics Data System (ADS)

    Kallman, J.; MacLaren, S.; Baker, K.; Amala, P.; Lewis, K.; Zika, M.

    2012-10-01

    The problem of radiation flow in a right circular cylinder is of interest for the verification and validation of radiation codes, which utilize several mechanisms for determining radiation transport (diffusion, discrete ordinates, and Monte Carlo). This flow is analogous to free molecular flow in a similar geometry.footnotetextE. Garelis and T.E. Wainwright. Phys. Fluids. 16, 4 (1973) A series of experiments were conducted on the OMEGA laser in cases with a low-density heated cylindrical wall. The experiments consisted of a 1.6 mm diameter gold hohlraum containing an on-axis 700 μm diameter SiO2 cylinder contained in an 80 μm thick carbon foam tube. Five shots panning three test cases were used: the nominal geometry described above (heated wall), the carbon tube replaced with solid gold, and a gold cap placed on the laser end of the cylinder assembly to block axial radiation flow. Simulations of each experimental target type were run with the KULL radiation code, and were used to compare the different radiation transport packages in KULL by employing synthetic diagnostics to match the experimental DANTE cavity radiation temperature time history and soft x-ray images taken by a streak camera imaging the far end of the hohlraum.

  12. Magnetized plasma jets in experiment and simulation

    NASA Astrophysics Data System (ADS)

    Schrafel, Peter; Greenly, John; Gourdain, Pierre; Seyler, Charles; Blesener, Kate; Kusse, Bruce

    2013-10-01

    This research focuses on the initial ablation phase of a thing (20 micron) Al foil driven on the 1 MA-in-100 ns COBRA through a 5 mm diameter cathode in a radial configuration. In these experiments, ablated surface plasma (ASP) on the top of the foil and a strongly collimated axial plasma jet can be observed developing midway through current-rise. Our goal is to establish the relationship between the ASP and the jet. These jets are of interest for their potential relevance to astrophysical phenomena. An independently pulsed 200 μF capacitor bank with a Helmholtz coil pair allows for the imposition of a slow (150 μs) and strong (~1 T) axial magnetic field on the experiment. Application of this field eliminates significant azimuthal asymmetry in extreme ultraviolet emission of the ASP. This asymmetry is likely a current filamentation instability. Laser-backlit shadowgraphy and interferometry confirm that the jet-hollowing is correlated with the application of the axial magnetic field. Visible spectroscopic measurements show a doppler shift consistent with an azimuthal velocity in the ASP caused by the applied B-field. Computational simulations with the XMHD code PERSEUS qualitatively agree with the experimental results.

  13. Computer Simulations of the Toroidal Cusp Experiment.

    NASA Astrophysics Data System (ADS)

    Ratliff, Steven Theodore

    1982-03-01

    The Toroidal Cusp Experiment (TCX) is a toroidal plasma device in which the external magnetic field is produced by permanent magnets arranged in 48 poloidal rings to form 48 magnetic cusps (the maximum field strength is 1.3 kG). A transformer drives a toroidal current which produces a Hydrogen plasma with n(,e) = electron density = 1.2 x 10('13)cm(' -3), T(,i) = ion temperature = 40 - 100 eV, T(,e) = electron temperature = 10 - 20 eV, and (beta) = ratio of maximum plasma pressure to maximum magnetic field pressure = 20% to 30%. The purpose of this dissertation is to investigate some physical phenomena in TCX by using theory and computer simulations. The operation of TCX is simulated by using a 2 1/2 dimensional ((PAR-DIFF)/(PAR-DIFF)z = 0) electromagnetic particle code. The positions (x, y) and velocities (v(,x), v(,y), v(,z)) of ions and electrons are calculated using the Lorentz force law and the electric and magnetic fields are calculated from the full set of Maxwell's equations. The computer model is described and its relationship to the experiment is given. Simple explanations of the magnetic lens effect of the array of 48 magnetic cusps and of the pinch effect are given. A simple theory is used to explain how the ratio of electron-to-ion toroidal current could be less than the mass ratio m(,i)/m(,e). Pressure balance results and a simple physical picture are explained. Electron and ion currents in the model are estimated from average velocities. The electrons are restrained by the cusp fields and the ions are relatively unrestrained. The cusp fields are stretched in the direction of the electron acceleration. The electrons execute E(' )x(' )B motion in the cusps; the ions are relatively unaffected by the cusp fields. For strong enough electric fields, an instability is observed in the computer model. We give evidence and theoretical arguments that this instability is a type of two-stream instability in which the streaming electrons in the center of the device

  14. Herbicide Persistence in Seawater Simulation Experiments

    PubMed Central

    Mercurio, Philip; Mueller, Jochen F.; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P.

    2015-01-01

    Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

  15. Herbicide Persistence in Seawater Simulation Experiments.

    PubMed

    Mercurio, Philip; Mueller, Jochen F; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P

    2015-01-01

    Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

  16. Combined analysis of short-baseline neutrino experiments in the (3+1) and (3+2) sterile neutrino oscillation hypotheses

    SciTech Connect

    Sorel, M.; Conrad, J.M.; Shaevitz, M.H.

    2004-10-01

    We investigate adding two sterile neutrinos to resolve the apparent tension existing between short-baseline neutrino oscillation results and CPT-conserving, four-neutrino oscillation models. For both (3+1) and (3+2) models, the level of statistical compatibility between the combined dataset from the null short-baseline experiments Bugey, CHOOZ, CCFR84, CDHS, KARMEN, and NOMAD, on the one hand; and the LSND dataset, on the other, is computed. A combined analysis of all seven short-baseline experiments, including LSND, is also performed, to obtain the favored regions in neutrino mass and mixing parameter space for both models. Finally, four statistical tests to compare the (3+1) and the (3+2) hypotheses are discussed. All tests show that (3+2) models fit the existing short-baseline data significantly better than (3+1) models.

  17. War-gaming application for future space systems acquisition part 1: program and technical baseline war-gaming modeling and simulation approaches

    NASA Astrophysics Data System (ADS)

    Nguyen, Tien M.; Guillen, Andy T.

    2017-05-01

    This paper describes static Bayesian game models with "Pure" and "Mixed" games for the development of an optimum Program and Technical Baseline (PTB) solution for affordable acquisition of future space systems. The paper discusses System Engineering (SE) frameworks and analytical and simulation modeling approaches for developing the optimum PTB solutions from both the government and contractor perspectives.

  18. Developing novel techniques for readout, calibration and event selection in the NOvA long-baseline neutrino experiment

    SciTech Connect

    Patterson, Ryan; Backhouse, Christopher; Bays, Kirk; Lozier, Joseph; Pershey, Daniel

    2016-10-01

    The NOvA long-baseline neutrino experiment uses a fine-grained, low-Z, fully active detector that offers unprecedented electron neutrino identification capabilities for a detector of its scale. In this award’s proposal, the PI outlined the development and implementation of novel techniques for channel readout, detector calibration, and event reconstruction that make full use of the strengths of the NOvA detector technology. In particular, this included designing custom event reconstruction algorithms that utilize the rich information available in the substructure of hadronic and electromagnetic showers. Exploiting this information provides not only substantial improvement in background rejection for the electron neutrino search but also better shower energy resolution (improving the precision on measured oscillation parameters) and a high-energy electromagnetic calibration source (through neutral pion events). The PI further proposed developing and deploying a new electronics readout scheme compatible with the existing hardware that can reduce near detector event pile-up and can offer powerful timing information to the reconstruction, allowing for cosmic ray muon tagging via track direction determination, among other things. In conjunction with the above, the PI proposed leading the calibration of the NOvA detectors, including characterizing individual electronics channels, correcting for spatial variations across the detector, and establishing absolute event energy scales. All three of these lines of effort have been successfully completed, feeding directly into the NOvA’s recent exciting neutrino oscillation results. The techniques developed under this award are detailed in this final technical report.

  19. Neutrino oscillations from warped flavor symmetry: Predictions for long baseline experiments T2K, NOvA, and DUNE

    NASA Astrophysics Data System (ADS)

    Pasquini, Pedro; Chuliá, Salvador Centelles; Valle, J. W. F.

    2017-05-01

    Here we study the pattern of neutrino oscillations emerging from a previously proposed warped standard model construction incorporating Δ (27 ) flavor symmetry [J. High Energy Phys. 01 (2016) 007, 10.1007/JHEP01(2016)007]. In addition to a complete description of fermion masses, the model predicts the lepton mixing matrix in terms of two parameters. The good measurement of θ13 makes these two parameters tightly correlated, leading to an approximate one-parameter description of neutrino oscillations. We find secondary minima for the C P phase absent in the general unconstrained oscillation scenario and determine the fourfold degenerate sharp correlation between the physical C P phase δC P and the atmospheric mixing angle θ23. This implies that maximal θ23 correlates with maximal leptonic C P violation. We perform a realistic estimate of the total neutrino and antineutrino event numbers expected at long baseline oscillation experiments T2K, NOvA, and the upcoming DUNE proposal. We show how an improved knowledge of the C P phase will probe the model in a significant way.

  20. Impact of lepton flavor universality violation on CP-violation sensitivity of long-baseline neutrino oscillation experiments

    NASA Astrophysics Data System (ADS)

    Soumya, C.; Mohanta, R.

    2017-01-01

    The observation of neutrino oscillation as well as the recent experimental results on lepton flavor universality (LFU) violation in B meson decays are indications of new physics beyond the standard model. Many theoretical models, which are introduced in the literature as an extension of SM to explain these observed deviations in LFU, lead to a new kind of interactions, the so-called non-standard interaction (NSI) between the elementary particles. In this paper, we consider a model with an additional Z' boson (which is quite successful in explaining the observed LFU anomalies) and analyze its effect in the lepton flavor violating (LFV) B_d→ τ ^± e^∓ decay modes. From the present upper bound of the B_d→ τ ^± e^∓ branching ratio, we obtain the constraints on the new physics parameters, which are related to the corresponding NSI parameters in the neutrino sector by SU(2)_L symmetry. These new parameters are expected to have potential implications in the neutrino oscillation studies and in this work we investigate the possibility of observing the effects of these interactions in the currently running and upcoming long-baseline experiments, i.e., NOν A and DUNE, respectively.

  1. Simulating Astrophysical Jets in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Bellan, Paul

    2004-11-01

    A laboratory plasma configuration based on spheromak [1] magnetic fusion plasma physics technology is used to simulate many important features of magnetically driven astrophysical jets. The experimental sequence starts with a quasi-static seed poloidal magnetic field that links a central disk electrode to a co-planar bounding annular electrode; this arrangement provides a topology analogous to the poloidal magnetic field of a star linking a surrounding accretion disk. After puffing neutral gas from nozzles mounted on the electrodes, plasma is created via application of a large emf between the central disk and the bounding annular electrode. The emf then drives a large poloidal electric current flowing from the central disk electrode (star) to the annulus (accretion disk) along the bias poloidal magnetic field. This electric current produces large magnetohydrodynamic forces which result in dynamics analogous to the dynamics of an astrophysical jet. In particular, the laboratory "astrophysical jet" is observed [2,3] to evolve through a distinct, reproducible sequence consisting of jet formation, collimation, kink instability, and for appropriate parameters, detachment into an unbounded, expanding spheromak-like plasmoid. These observations and related observations on a solar prominence simulation experiment [4] have motivated an analytic model [5] for the collimation physics whereby stagnation of convected, frozen-in toroidal magnetic flux amplifies the toroidal magnetic flux density and then, since the toroidal magnetic field (i.e., toroidal flux density) provides the pinch force, the pinch force is increased, collimating the jet. The following talk (You, Bellan, Yun) will present detailed measurements of the jet formation, acceleration, and collimation process. [1] P. M. Bellan, Spheromaks (Imperial College Press, London, 2000). [2] S. C. Hsu and P. M. Bellan, Mon. Not. R. Astron. Soc. 334, 257 (2002). [3] S. C. Hsu and P. M. Bellan, Phys. Rev. Letters 90, article

  2. Modeling active memory: Experiment, theory and simulation

    NASA Astrophysics Data System (ADS)

    Amit, Daniel J.

    2001-06-01

    Neuro-physiological experiments on cognitively performing primates are described to argue that strong evidence exists for localized, non-ergodic (stimulus specific) attractor dynamics in the cortex. The specific phenomena are delay activity distributions-enhanced spike-rate distributions resulting from training, which we associate with working memory. The anatomy of the relevant cortex region and the physiological characteristics of the participating elements (neural cells) are reviewed to provide a substrate for modeling the observed phenomena. Modeling is based on the properties of the integrate-and-fire neural element in presence of an input current of Gaussian distribution. Theory of stochastic processes provides an expression for the spike emission rate as a function of the mean and the variance of the current distribution. Mean-field theory is then based on the assumption that spike emission processes in different neurons in the network are independent, and hence the input current to a neuron is Gaussian. Consequently, the dynamics of the interacting network is reduced to the computation of the mean and the variance of the current received by a cell of a given population in terms of the constitutive parameters of the network and the emission rates of the neurons in the different populations. Within this logic we analyze the stationary states of an unstructured network, corresponding to spontaneous activity, and show that it can be stable only if locally the net input current of a neuron is inhibitory. This is then tested against simulations and it is found that agreement is excellent down to great detail. A confirmation of the independence hypothesis. On top of stable spontaneous activity, keeping all parameters fixed, training is described by (Hebbian) modification of synapses between neurons responsive to a stimulus and other neurons in the module-synapses are potentiated between two excited neurons and depressed between an excited and a quiescent neuron

  3. Physics potential of neutrino oscillation experiment with a far detector in Oki Island along the T2K baseline

    NASA Astrophysics Data System (ADS)

    Hagiwara, Kaoru; Kiwanami, Takayuki; Okamura, Naotoshi; Senda, Ken-ichi

    2013-06-01

    Oki Island is located between Japan and Korea along the Tokai-To-Kamioka (T2K) baseline. The distance from J-PARC to Oki Island is about 653km, which is twice that of the T2K experiment ( L = 295km). When the off-axis angle of the neutrino beam from J-PARC is 3 .0° (2 .0°) at Super-Kamiokande (SK), the off-axis beam (OAB) with 1 .4° (0 .6°) reaches at Oki Island. We examine physics case of placing a far detector in Oki Island during the T2K experimental period. We estimate the matter density profile along the Tokai-to-Oki baseline by using recent seismological measurements. For a detector of 100 kton fiducial volume and 2 .5 × 1021 POT (protons on target) exposure for both ν μ and {{overline{ν}}_{μ }} beams, we find that the mass hierarchy pattern can be distinguished at 3 σ level if sin2 2 θ RCT ≡ 4| U e3|2(1 - | U e3 |2) ≳ 0 .09, by observing the electron-like CCQE (Charged-Current Quasi Elastic) events. The CP phase in the Maki-Nakagawa-Sakata lepton flavor mixing matrix, δ MNS, can be constrained with ±20°. As a reference, we repeat the same analysis by placing the same detector in Korea at L = 1000 km and OAB=0 .5° (T2KK) and also by placing it at the SK site (T2K122). The Tokai-to-Kamioka-OKI (T2KO) sensitivity to the mass hierarchy is about 1 /3 (in \\varDelta χ_{min}^2 ) of T2KK, while the sensitivity to the phase δ MNS is similar between T2KO and T2KK. The T2K122 option has almost no sensitivity to the mass hierarchy, and cannot measure the CP phase except when δ MNS -90° (90°) for the normal (inverted) hierarchy.

  4. Recirculating planar magnetrons: simulations and experiment

    SciTech Connect

    Franzi, Matthew; Gilgenbach, Ronald; French, David; Lau, Y.Y.; Simon, David; Hoff, Brad; Luginsland, John W.

    2011-07-01

    The Recirculating Planar Magnetron (RPM) is a novel crossed-field device whose geometry is expected to reduce thermal load, enhance current yield as well as ease the geometric limitations in scaling to high RF frequencies as compared to the conventional cylindrical magnetrons. The RPM has two different adaptations: A. Axial B field and radial E field; B. Radial B field and axial E field. The preliminary configuration (A) to be used in experiments at the University of Michigan consists of two parallel planar sections which join on either end by cylindrical regions to form a concentric extruded ellipse. Similar to conventional magnetrons, a voltage across the AK gap in conjunction with an axial magnetic field provides the electrons with an ExB drift. The device is named RPM because the drifting electrons recirculate from one planar region to the other. The drifting electrons interact with the resonantly tuned slow wave structure on the anode causing spoke formation. These electron spokes drive a RF electric field in the cavities from which RF power may be extracted to Waveguides. The RPM may be designed in either a conventional configuration with the anode on the outside, for simplified extraction, or as an inverted magnetron with the anode at the inner conductor, for fast start-up. Currently, experiments at the Pulsed Power and Microwave Laboratory at the University of Michigan are in the setup and design phase. A conventional RPM with planar cavities is to be installed on the Michigan Electron Long Beam Accelerator (MELBA) and is anticipated to operate at -200kV, 0.2T with a beam current of 1-10 kA at 1GHz. The conventional RPM consists of 12 identical planar cavities, 6 on each planar side, with simulated quality factor of 20.

  5. The Marble Experiment: Overview and Simulations

    NASA Astrophysics Data System (ADS)

    Douglas, M. R.; Murphy, T. J.; Cobble, J. A.; Fincke, J. R.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Olson, R. E.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

    2015-11-01

    The Marble ICF platform has recently been launched on both OMEGA and NIF with the goal to investigate the influence of heterogeneous mix on fusion burn. The unique separated reactant capsule design consists of an ``engineered'' CH capsule filled with deuterated plastic foam that contains pores or voids that are filled with tritium gas. Initially the deuterium and tritium are separated, but as the implosion proceeds, the D and T mix, producing a DT signature. The results of these experiments will be used to inform a probability density function (PDF) burn modelling approach for un-resolved cell morphology. Initial targets for platform development have consisted of either fine-pore foams or gas mixtures, with the goal to field the engineered foams in 2016. An overview of the Marble experimental campaign will be presented and simulations will be discussed. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

  6. Background simulations for the ECHo experiment

    NASA Astrophysics Data System (ADS)

    Scholl, S.; Zschocke, A.; Jochum, J.

    2017-09-01

    ECHo-1K is an experiment designed to measure the electron neutrino mass from the spectrum of the electron capture on 163Ho using an array of 100 magnetic micro calorimeters each loaded with 10 Bq of 163Ho. In this article, we present the results of our activities in the investigation of possible backgrounds to the electron capture spectrum using GEANT4 based Monte-Carlo simulations of the sources 166mHo, 40K, 210Pb and the 238U decay chain. For standard contaminations of the used materials, the contribution of the investigated sources is well below the background induced by the pile-up of 163Ho decays. Nonetheless, care has to be taken to avoid accidental contamination during the manufacturing and storage of the detectors, since a few mBq in total on the surface of all 100 detectors of either 40K (∼ 12 mBq) from residual potassium, or 210Pb (∼ 4 mBq) from radon emanation yield a background as large as the expected signal.

  7. Liquid crystal interfaces: Experiments, simulations and biosensors

    NASA Astrophysics Data System (ADS)

    Popov, Piotr

    Interfacial phenomena are ubiquitous and extremely important in various aspects of biological and industrial processes. For example, many liquid crystal applications start by alignment with a surface. The underlying mechanisms of the molecular organization of liquid crystals at an interface are still under intensive study and continue to be important to the display industry in order to develop better and/or new display technology. My dissertation research has been devoted to studying how complex liquid crystals can be guided to organize at an interface, and to using my findings to develop practical applications. Specifically, I have been working on developing biosensors using liquid-crystal/surfactant/lipid/protein interactions as well as the alignment of low-symmetry liquid crystals for potential new display and optomechanical applications. The biotechnology industry needs better ways of sensing biomaterials and identifying various nanoscale events at biological interfaces and in aqueous solutions. Sensors in which the recognition material is a liquid crystal naturally connects the existing knowledge and experience of the display and biotechnology industries together with surface and soft matter sciences. This dissertation thus mainly focuses on the delicate phenomena that happen at liquid interfaces. In the introduction, I start by defining the interface and discuss its structure and the relevant interfacial forces. I then introduce the general characteristics of biosensors and, in particular, describe the design of biosensors that employ liquid crystal/aqueous solution interfaces. I further describe the basic properties of liquid crystal materials that are relevant for liquid crystal-based biosensing applications. In CHAPTER 2, I describe the simulation methods and experimental techniques used in this dissertation. In CHAPTER 3 and CHAPTER 4, I present my computer simulation work. CHAPTER 3 presents insight of how liquid crystal molecules are aligned by

  8. Impact of an Advanced Cardiac Life Support Simulation Laboratory Experience on Pharmacy Student Confidence and Knowledge.

    PubMed

    Maxwell, Whitney D; Mohorn, Phillip L; Haney, Jason S; Phillips, Cynthia M; Lu, Z Kevin; Clark, Kimberly; Corboy, Alex; Ragucci, Kelly R

    2016-10-25

    Objective. To assess the impact of an advanced cardiac life support (ACLS) simulation on pharmacy student confidence and knowledge. Design. Third-year pharmacy students participated in a simulation experience that consisted of team roles training, high-fidelity ACLS simulations, and debriefing. Students completed a pre/postsimulation confidence and knowledge assessment. Assessment. Overall, student knowledge assessment scores and student confidence scores improved significantly. Student confidence and knowledge changes from baseline were not significantly correlated. Conversely, a significant, weak positive correlation between presimulation studying and both presimulation confidence and presimulation knowledge was discovered. Conclusions. Overall, student confidence and knowledge assessment scores in ACLS significantly improved from baseline; however, student confidence and knowledge were not significantly correlated.

  9. Impact of an Advanced Cardiac Life Support Simulation Laboratory Experience on Pharmacy Student Confidence and Knowledge

    PubMed Central

    Mohorn, Phillip L.; Haney, Jason S.; Phillips, Cynthia M.; Lu, Z. Kevin; Clark, Kimberly; Corboy, Alex; Ragucci, Kelly R.

    2016-01-01

    Objective. To assess the impact of an advanced cardiac life support (ACLS) simulation on pharmacy student confidence and knowledge. Design. Third-year pharmacy students participated in a simulation experience that consisted of team roles training, high-fidelity ACLS simulations, and debriefing. Students completed a pre/postsimulation confidence and knowledge assessment. Assessment. Overall, student knowledge assessment scores and student confidence scores improved significantly. Student confidence and knowledge changes from baseline were not significantly correlated. Conversely, a significant, weak positive correlation between presimulation studying and both presimulation confidence and presimulation knowledge was discovered. Conclusions. Overall, student confidence and knowledge assessment scores in ACLS significantly improved from baseline; however, student confidence and knowledge were not significantly correlated. PMID:27899836

  10. Fluid criticality: Experiment, scaling and simulations

    NASA Astrophysics Data System (ADS)

    Kim, Youngchan

    Understanding fluid criticality has been a long-standing issue---a challenge to both theorists and experimentalists for more than a century. This thesis discusses the topic extensively first within mean-field theory and then more realistically within a new "complete" scaling theory that also extends to finite systems. The complete scaling theory incorporates pressure mixing which is crucial to describe the so-called Yang-Yang anomaly characterized by the divergence of the second derivative of the chemical potential on the phase boundary at the critical point. For use in simulations and experiments, various interesting loci are introduced that intersect the critical point in the temperature-density and other thermodynamic planes. More specifically, the phase boundaries and their analytic continuations through criticality in the (rho, T), ( p, T), (mu, T), etc., planes are derived within mean-field theory and illustrated quantitatively by using the van der Waals equation. These same critical loci are then studied within the complete scaling theory. Of particular significance for analysis in simulations are the so-called k-loci, the CkV -loci and, especially, the Q-loci. These loci are applied to estimate the critical parameters, Tc, and rhoc, and the correlation-length exponent, nu, for the hard-core square-well fluid and for the restricted primitive model electrolyte. Bruce and Wilding's finite-size scaling method, that provides an efficient way of estimating T c and rhoc provided the critical universality class is known, is discussed thoroughly and criticized on the basis of the complete scaling theory. The issue of understanding in detail the criticality of electrolyte solutions is still under active investigation. Here a simpler question is addressed: namely, what are the effects on the critical parameters of a simple fluid of adding an ionic salt? On the basis of van der Waals theory and Debye-Huckel theory, it is shown that the critical parameters, T c

  11. Experiments and simulating on dehydration of antigorite

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, D.

    2016-12-01

    Antigorite is a key hydrous minerals in subduction zone. Dehydration of antigorite is related to many geodynamics processes, for examples, the dehydration of antigorite is thought to cause the seismicity of the lower plane located in a double seismic zone. Therefore, it is necessary to study the dehydration kinetics of antigorite. Previous studies show the results of antigorite dehydration using M XRD and FTIR. In this study, we report the new results of dehydration kinetics of antigorite by thermogravimetric(TG) analysis, and develop a new model to simulate the dehydration. The dehydration experiments using antigorite with a grain size 5-10μm were determined by non-isothermal methods with heating rate of 5, 10, 15, 20, 25 K/min up to 1260K. The results show the reaction progress of dehydration varied with the heating rates. Considering the various activation energy of hydroxyl groups in different locations, we used a double-Gaussian distributed activation energy model to fit the experimental results of antigorite. In this model, we assure that two sets of parallel reactions occur sharing the same pre-exponential factor but not sharing the same distribution of activation energy. Simulated annealing algorithm is adopted in solving pre-exponential factor(κ), weight(ω), two mean activation energies(Ε1 and Ε2) couplied with two standard deviations(σ1 and σ2). Five solutions can fit well the experimental data and ln(κ) linearly changes with average activation energy. κ is fixed —10^13/s which is closed to atom vibration frequency. The correlation coefficient between experimental data and fitting result is 0.999. The first step of dehydration is distributed in a wide interval of activation energy(E1=268.1kJ/mol,σ1=29.8kJ/mol) , but the second dehydration step is confined in a narrow interval(E1=299.2kJ/mol,σ1=8.9kJ/mol) at higher activation energy. We determined that the release of aqueous fluid is 1.8×10^(-4), 4.2×10^(-4), 9.7×10^(-4), 2.2×10^(-3), 4.6

  12. Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE): Conceptual Design Report. Volume 1: The LBNF and DUNE Projects

    SciTech Connect

    Acciarri, R.

    2016-01-22

    This document presents the Conceptual Design Report (CDR) put forward by an international neutrino community to pursue the Deep Underground Neutrino Experiment at the Long-Baseline Neutrino Facility (LBNF/DUNE), a groundbreaking science experiment for long-baseline neutrino oscillation studies and for neutrino astrophysics and nucleon decay searches. The DUNE far detector will be a very large modular liquid argon time-projection chamber (LArTPC) located deep underground, coupled to the LBNF multi-megawatt wide-band neutrino beam. DUNE will also have a high-resolution and high-precision near detector.

  13. Observing System Simulation Experiments for Hurricanes

    NASA Astrophysics Data System (ADS)

    Atlas, R. M.; Hoffman, R. N.; Bucci, L. R.; Annane, B.; Murillo, S.

    2015-12-01

    Observing System Simulation Experiments (OSSEs), when done correctly, provide an effective means to evaluate the potential impact of a proposed observing system, as well as to determine tradeoffs in their design, and to evaluate data assimilation methodology. Great care must be taken to ensure the realism of the OSSEs and in the interpretation of OSSE results. While early OSSEs focused on large-scale numerical weather prediction, more recent OSSEs have included evaluation of the impact of proposed observing systems on smaller-scale phenomena. These have included global OSSEs to evaluate impact on hurricane track forecasting and regional OSSEs aimed at evaluating both track and intensity prediction. Two global OSSEs conducted using the fvGCM nature runs showed a substantial impact of space-based lidar wind profiles on hurricane track predictions. Current OSSEs are using multiple nature runs in which the WRF model, at very high resolution, is embedded within a global T511 nature run that had been generated by ECMWF. These OSSEs are evaluating the potential impact of new (proposed) observing systems on hurricane track and intensity prediction and trade-offs in the design and configuration of these observing systems They are also being used to optimize sampling strategies for current and future airborne and spaceborne observing systems and to evaluate and improve data assimilation and vortex initialization methodology for hurricane prediction. Results from recent OSSEs show the relative impact of alternative lidar technologies and the relative impact of global and regional assimilation on hurricane track and intensity prediction. OSSEs are currently underway to evaluate advanced concepts for hyperspectral infrared (IR) sounding from both polar and geostationary orbit, as well as to evaluate a variety of aspects of hurricane predictability.

  14. Simulation and analysis software for the NICA experiments

    NASA Astrophysics Data System (ADS)

    Gertsenberger, K.; Merts, S.; Rogachevsky, O.; Zinchenko, A.

    2016-08-01

    Software frameworks, developed for the NICA experiments are described briefly. The tools used for the physics event generation, detector simulation, particle reconstruction and visualization are considered.

  15. Simulation Learning Experiences in Speech Communication.

    ERIC Educational Resources Information Center

    Cheathan, T. Richard; Erickson, Keith V.

    This study, the first national survey of an academic discipline's use of simulation and game exercises, constitutes an attempt to determine the status, rationale, and effectiveness of such exercises. Specifically, members of the Speech Communication Association were surveyed regarding the courses in which simulations and games are employed, the…

  16. Business Simulation Games: The Hong Kong Experience

    ERIC Educational Resources Information Center

    Chang, Jimmy; Lee, Mary; Ng, Kwan-ling; Moon, Ka-Leung

    2003-01-01

    This article describes the results of a survey of 93 final-year degree students concerning their views toward using Thavikulwat's DEAL: A Business Gaming Simulation. The focus is on students' perception of the usefulness of using computer simulation as a learning tool in a strategic management course. Certain comparison was made with other similar…

  17. Simulating Dynamic Equilibria: A Class Experiment

    NASA Astrophysics Data System (ADS)

    Harrison, John A.; Buckley, Paul D.

    2000-08-01

    A first-order reversible reaction is simulated on an overhead projector using small coins or discs. A simulation is carried out in which initially there are 24 discs representing reactant A and none representing reactant B. At the end of each minute half of the reactant A discs get converted to reactant B, and one quarter of the reactant B discs get converted to reactant A discs. Equilibrium is established with 8 A discs and 16 B discs, and no further net change is observed as the simulation continues. Another simulation beginning with 48 A discs and 0 B discs leads at equilibrium to 16 A discs and 32 B discs. These results illustrate how dynamic equilibria are established and allow the introduction of the concept of an equilibrium constant. Le Châtelier's principle is illustrated by further simulations.

  18. Bias, precision and statistical power of analysis of covariance in the analysis of randomized trials with baseline imbalance: a simulation study

    PubMed Central

    2014-01-01

    Background Analysis of variance (ANOVA), change-score analysis (CSA) and analysis of covariance (ANCOVA) respond differently to baseline imbalance in randomized controlled trials. However, no empirical studies appear to have quantified the differential bias and precision of estimates derived from these methods of analysis, and their relative statistical power, in relation to combinations of levels of key trial characteristics. This simulation study therefore examined the relative bias, precision and statistical power of these three analyses using simulated trial data. Methods 126 hypothetical trial scenarios were evaluated (126 000 datasets), each with continuous data simulated by using a combination of levels of: treatment effect; pretest-posttest correlation; direction and magnitude of baseline imbalance. The bias, precision and power of each method of analysis were calculated for each scenario. Results Compared to the unbiased estimates produced by ANCOVA, both ANOVA and CSA are subject to bias, in relation to pretest-posttest correlation and the direction of baseline imbalance. Additionally, ANOVA and CSA are less precise than ANCOVA, especially when pretest-posttest correlation ≥ 0.3. When groups are balanced at baseline, ANCOVA is at least as powerful as the other analyses. Apparently greater power of ANOVA and CSA at certain imbalances is achieved in respect of a biased treatment effect. Conclusions Across a range of correlations between pre- and post-treatment scores and at varying levels and direction of baseline imbalance, ANCOVA remains the optimum statistical method for the analysis of continuous outcomes in RCTs, in terms of bias, precision and statistical power. PMID:24712304

  19. Actual Operation Simulation of RESSOX Ground Experiments

    DTIC Science & Technology

    2010-11-01

    experiments with VCOCXO control of Experiment Two. In Experiment One, the remote synchronization system of the onboard crystal oscillator (RESSOX...Experiment One, the remote synchronization system of the onboard crystal oscillator (RESSOX) control signal that includes information of the standard time...receive navigation signals from at least one of the QZSs near the zenith. In general, a global navigation satellite system ( GNSS ), such as the GPS of

  20. Reproducible computational biology experiments with SED-ML--the Simulation Experiment Description Markup Language.

    PubMed

    Waltemath, Dagmar; Adams, Richard; Bergmann, Frank T; Hucka, Michael; Kolpakov, Fedor; Miller, Andrew K; Moraru, Ion I; Nickerson, David; Sahle, Sven; Snoep, Jacky L; Le Novère, Nicolas

    2011-12-15

    The increasing use of computational simulation experiments to inform modern biological research creates new challenges to annotate, archive, share and reproduce such experiments. The recently published Minimum Information About a Simulation Experiment (MIASE) proposes a minimal set of information that should be provided to allow the reproduction of simulation experiments among users and software tools. In this article, we present the Simulation Experiment Description Markup Language (SED-ML). SED-ML encodes in a computer-readable exchange format the information required by MIASE to enable reproduction of simulation experiments. It has been developed as a community project and it is defined in a detailed technical specification and additionally provides an XML schema. The version of SED-ML described in this publication is Level 1 Version 1. It covers the description of the most frequent type of simulation experiments in the area, namely time course simulations. SED-ML documents specify which models to use in an experiment, modifications to apply on the models before using them, which simulation procedures to run on each model, what analysis results to output, and how the results should be presented. These descriptions are independent of the underlying model implementation. SED-ML is a software-independent format for encoding the description of simulation experiments; it is not specific to particular simulation tools. Here, we demonstrate that with the growing software support for SED-ML we can effectively exchange executable simulation descriptions. With SED-ML, software can exchange simulation experiment descriptions, enabling the validation and reuse of simulation experiments in different tools. Authors of papers reporting simulation experiments can make their simulation protocols available for other scientists to reproduce the results. Because SED-ML is agnostic about exact modeling language(s) used, experiments covering models from different fields of research

  1. Reproducible computational biology experiments with SED-ML - The Simulation Experiment Description Markup Language

    PubMed Central

    2011-01-01

    Background The increasing use of computational simulation experiments to inform modern biological research creates new challenges to annotate, archive, share and reproduce such experiments. The recently published Minimum Information About a Simulation Experiment (MIASE) proposes a minimal set of information that should be provided to allow the reproduction of simulation experiments among users and software tools. Results In this article, we present the Simulation Experiment Description Markup Language (SED-ML). SED-ML encodes in a computer-readable exchange format the information required by MIASE to enable reproduction of simulation experiments. It has been developed as a community project and it is defined in a detailed technical specification and additionally provides an XML schema. The version of SED-ML described in this publication is Level 1 Version 1. It covers the description of the most frequent type of simulation experiments in the area, namely time course simulations. SED-ML documents specify which models to use in an experiment, modifications to apply on the models before using them, which simulation procedures to run on each model, what analysis results to output, and how the results should be presented. These descriptions are independent of the underlying model implementation. SED-ML is a software-independent format for encoding the description of simulation experiments; it is not specific to particular simulation tools. Here, we demonstrate that with the growing software support for SED-ML we can effectively exchange executable simulation descriptions. Conclusions With SED-ML, software can exchange simulation experiment descriptions, enabling the validation and reuse of simulation experiments in different tools. Authors of papers reporting simulation experiments can make their simulation protocols available for other scientists to reproduce the results. Because SED-ML is agnostic about exact modeling language(s) used, experiments covering models from

  2. Experiments and mathematical simulation of plate distortion simulators

    NASA Astrophysics Data System (ADS)

    Zhang, S.-Y.; Gao, S.-T.

    A numerical model is described for the flowfield around plates used in plate distortion simulators. Attention is given to the direct problem, the flow behind the plates, and the inverse problem, the sizes and locations of plates that will generate the flowfield defined by the simulation. The method is shown to allow calculation of the Fourier coefficients of the circumferential pressure distribution, a value for the DC60 term, and the total pressure recovery contour. Comparisons are offered between the calculated values and experimentally obtained values measured with a rake, and good agreement is demonstrated.

  3. Climate dynamics experiments using a GCM simulations

    NASA Technical Reports Server (NTRS)

    Fitzjarrald, Dan; Robertson, Franklin R.; Christy, John R.; Lu, H.-I.; Sohn, B.; Srikishen, J.

    1991-01-01

    The study of surface-atmosphere interactions has begun with studies of the effect of altering the ocean and land boundaries. A ten year simulation of global climate using observed sea surface temperature anomalies has begun using the NCAR Community Climate Model (CCM1). The results for low resolution (R15) were computed for the first 8 years of the simulation and compared with the observed surface temperatures and the MSU (Microwave Sounding Unit) observations of tropospheric temperature. A simulation at higher resolution (T42) was done to ascertain the effect of interactive soil hydrology on the system response to an El Nino sea surface temperature perturbation. Initial analysis of this simulations was completed.

  4. Experiences with the MANA simulation tool

    DTIC Science & Technology

    2006-08-01

    indicated as with the title.) Map Aware Non-uniform Automata , MANA, Agent-based, Modelling , Simulation, Future Armoured Vehicle System, FAVS, Advanced... Automata (MANA) agent-based simulation tool has drawn interest in the military Operational Research community. After encountering difficulties with...more resource-intensive higher-fidelity models , the DRDC Valcartier Operational Research (OR) Team considered MANA as a possible tool for fulfilling

  5. Development of Very Long Baseline Interferometry (VLBI) techniques in New Zealand: Array simulation, image synthesis and analysis

    NASA Astrophysics Data System (ADS)

    Weston, S. D.

    2008-04-01

    This thesis presents the design and development of a process to model Very Long Base Line Interferometry (VLBI) aperture synthesis antenna arrays. In line with the Auckland University of Technology (AUT) Institute for Radiophysics and Space Research (IRSR) aims to develop the knowledge, skills and experience within New Zealand, extensive use of existing radio astronomical software has been incorporated into the process namely AIPS (Astronomical Imaging Processing System), MIRIAD (a radio interferometry data reduction package) and DIFMAP (a program for synthesis imaging of visibility data from interferometer arrays of radio telescopes). This process has been used to model various antenna array configurations for two proposed New Zealand sites for antenna in a VLBI array configuration with existing Australian facilities and a passable antenna at Scott Base in Antarctica; and the results are presented in an attempt to demonstrate the improvement to be gained by joint trans-Tasman VLBI observation. It is hoped these results and process will assist the planning and placement of proposed New Zealand radio telescopes for cooperation with groups such as the Australian Long Baseline Array (LBA), others in the Pacific Rim and possibly globally; also potential future involvement of New Zealand with the SKA. The developed process has also been used to model a phased building schedule for the SKA in Australia and the addition of two antennas in New Zealand. This has been presented to the wider astronomical community via the Royal Astronomical Society of New Zealand Journal, and is summarized in this thesis with some additional material. A new measure of quality ("figure of merit") for comparing the original model image and final CLEAN images by utilizing normalized 2-D cross correlation is evaluated as an alternative to the existing subjective visual operator image comparison undertaken to date by other groups. This new unit of measure is then used ! in the presentation of the

  6. Three-dimensional MHD simulation of the Caltech plasma jet experiment: first results

    SciTech Connect

    Zhai, Xiang; Bellan, Paul M.; Li, Hui; Li, Shengtai E-mail: pbellan@caltech.edu E-mail: sli@lanl.gov

    2014-08-10

    Magnetic fields are believed to play an essential role in astrophysical jets with observations suggesting the presence of helical magnetic fields. Here, we present three-dimensional (3D) ideal MHD simulations of the Caltech plasma jet experiment using a magnetic tower scenario as the baseline model. Magnetic fields consist of an initially localized dipole-like poloidal component and a toroidal component that is continuously being injected into the domain. This flux injection mimics the poloidal currents driven by the anode-cathode voltage drop in the experiment. The injected toroidal field stretches the poloidal fields to large distances, while forming a collimated jet along with several other key features. Detailed comparisons between 3D MHD simulations and experimental measurements provide a comprehensive description of the interplay among magnetic force, pressure, and flow effects. In particular, we delineate both the jet structure and the transition process that converts the injected magnetic energy to other forms. With suitably chosen parameters that are derived from experiments, the jet in the simulation agrees quantitatively with the experimental jet in terms of magnetic/kinetic/inertial energy, total poloidal current, voltage, jet radius, and jet propagation velocity. Specifically, the jet velocity in the simulation is proportional to the poloidal current divided by the square root of the jet density, in agreement with both the experiment and analytical theory. This work provides a new and quantitative method for relating experiments, numerical simulations, and astrophysical observation, and demonstrates the possibility of using terrestrial laboratory experiments to study astrophysical jets.

  7. Simulation of the SBS Polarimeter for GEp(5) Experiment

    NASA Astrophysics Data System (ADS)

    Wang, Yang; SBS Collaboration

    2013-10-01

    Before running experiment GEp(5), we need to predict the characteristic performance of the Focal Plane Polarimeter (FPP) required for the experiment with a simulation of the processes involved. In the simulation, the probability that a proton incident on the polarimeter will generate a single and charged particle which can be detected by the tracking detectors is evaluated. In this talk, the results of the simulation will be displayed, such as the scattering angle distribution, the interaction position and the cone-test result of the detected charged particles; prediction for the probability to detect a single charged track versus incident proton momentum will be shown. Simulation of the conditions of experiment GEp(2 γ) was made to check the reliability of the simulation. The difference between the simulation and the experiment data will be discussed.

  8. Computer simulations and experiments: The case of the Higgs boson

    NASA Astrophysics Data System (ADS)

    Massimi, Michela; Bhimji, Wahid

    2015-08-01

    Simulations have been at the center of an important literature that has debated the extent to which they count as epistemologically on a par with traditional experiments. Critics have raised doubts about simulations being genuine experiments, on the ground that simulations seem to lack a distinctive feature of traditional experiments: i.e., the ability to causally interact with a target system. In this paper, we defend the view that simulations are indeed epistemologically on a par with traditional experiments. We first identify three possible ways of understanding the causal interaction claim. We then focus on the use of simulation in the discovery of the Higgs boson to show that in this paradigmatic case, simulations satisfy all three possible readings of the causal interaction claim.

  9. EBW simulation for MAST and NSTX experiments

    SciTech Connect

    Preinhaelter, J.; Urban, J.; Pavlo, P.; Shevchenko, V.; Valovic, M.; Vahala, G.

    2005-09-26

    The interpretation of EBW emission from spherical tokamaks is nontrivial. We report on a 3D simulation model of this process that incorporates Gaussian beams for the antenna, a full wave solution of EBW-X and EBW-X-O conversions using adaptive finite elements, and EBW ray tracing to determine the radiative temperature. This model is then used to interpret the experimental results from MAST and NSTX. EBW for ELM free H-modes in MAST suggests that the magnetic equilibrium determined by the EFIT code does not adequately represent the B-field within the transport barrier. Using the EBW signal for the reconstruction of the radial profile of the magnetic field, we determine a new equilibrium and see that the EBW simulation now yields better agreement with experimental results. EBW simulations yield excellent results for the time development of the plasma temperature as measured by the EBW radiometer on NSTX.

  10. Comparing simulation of plasma turbulence with experiment

    NASA Astrophysics Data System (ADS)

    Ross, David W.; Bravenec, Ronald V.; Dorland, William; Beer, Michael A.; Hammett, G. W.; McKee, George R.; Fonck, Raymond J.; Murakami, Masanori; Burrell, Keith H.; Jackson, Gary L.; Staebler, Gary M.

    2002-01-01

    The direct quantitative correspondence between theoretical predictions and the measured plasma fluctuations and transport is tested by performing nonlinear gyro-Landau-fluid simulations with the GRYFFIN (or ITG) code [W. Dorland and G. W. Hammett, Phys. Fluids B 5, 812 (1993); M. A. Beer and G. W. Hammett, Phys. Plasmas 3, 4046 (1996)]. In an L-mode reference discharge in the DIII-D tokamak [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)], which has relatively large fluctuations and transport, the turbulence is dominated by ion temperature gradient (ITG) modes. Trapped electron modes and impurity drift waves also play a role. Density fluctuations are measured by beam emission spectroscopy [R. J. Fonck, P. A. Duperrex, and S. F. Paul, Rev. Sci. Instrum. 61, 3487 (1990)]. Experimental fluxes and corresponding diffusivities are analyzed by the TRANSP code [R. J. Hawryluk, in Physics of Plasmas Close to Thermonuclear Conditions, edited by B. Coppi, G. G. Leotta, D. Pfirsch, R. Pozzoli, and E. Sindoni (Pergamon, Oxford, 1980), Vol. 1, p. 19]. The shape of the simulated wave number spectrum is close to the measured one. The simulated ion thermal transport, corrected for E×B low shear, exceeds the experimental value by a factor of 1.5 to 2.0. The simulation overestimates the density fluctuation level by an even larger factor. On the other hand, the simulation underestimates the electron thermal transport, which may be accounted for by modes that are not accessible to the simulation or to the BES measurement.

  11. Dynamic System Simulation of the KRUSTY Experiment

    SciTech Connect

    Klein, Steven Karl; Kimpland, Robert Herbert

    2016-05-09

    The proposed KRUSTY experiment is a demonstration of a reactor operating at power. The planned experimental configuration includes a highly enriched uranium (HEU) reflected core, cooled by multiple heat pipes leading to Stirling engines for primary heat rejection. Operating power is expected to be approximately four (4) to five (5) kilowatts with a core temperature above 1,000 K. No data is available on any historical reactor employing HEU metal that operated over the temperature range required for the KRUSTY experiment. Further, no reactor has operated with heat pipes as the primary cooling mechanism. Historic power reactors have employed either natural or forced convection so data on their operation is not directly applicable to the KRUSTY experiment. The primary purpose of the system model once developed and refined by data from these component experiments, will be used to plan the KRUSTY experiment. This planning will include expected behavior of the reactor from start-up, through various transient conditions where cooling begins to become present and effective, and finally establishment of steady-state. In addition, the model can provide indicators of anticipated off-normal events and appropriate operator response to those conditions. This information can be used to develop specific experiment operating procedures and aids to guide the operators in conduct of the experiment.

  12. Baseline program

    NASA Technical Reports Server (NTRS)

    Roberts, Barney B.; Vonputtkamer, Jesco

    1992-01-01

    This assumed program was developed from several sources of information and is extrapolated over future decades using a set of reasonable assumptions based on incremental growth. The assumptions for the NASA baseline program are as follows: balanced emphasis in four domains; a constant level of activity; low to moderate real budget growth; maximum use of commonality; and realistic and practical technology development. The first domain is low Earth Orbit (LEO). Activities there are concentrated on the space station but extend on one side to Earth-pointing sensors for unmanned platforms and on the other to the launch and staging of unmanned solar system exploration missions. The second domain is geosynchronous Earth orbit (GEO) and cislunar space. Activities here include all GEO missions and operations, both unmanned and manned, and all transport of materials and crews between LEO and the vicinity of the Moon. The third domain is the Moon itself. Lunar activities are to include both orbiting and landing missions; the landings may be either unmanned or manned. The last domain is Mars. Missions to Mars will initially be unmanned but they will eventually be manned. Program elements and descriptions are discussed as are critiques of the NASA baseline.

  13. Simulations of MATROSHKA experiment outside the ISS using PHITS

    NASA Astrophysics Data System (ADS)

    Puchalska, M.; Sihver, L.; Sato, T.; Berger, T.; Reitz, G.

    2012-08-01

    The radiation environment at the altitude of the International Space Station (ISS) is substantially different than anything typically encountered on Earth in both the character of the radiation field and the significantly higher dose rates. Concerns about the biological effects on humans of this highly complex natural radiation field are increasing due to higher amount of astronauts performing long-duration missions onboard the ISS and especially if looking into planned future manned missions to Mars. In order to begin the process of predicting the dose levels seen by the organs of an astronaut, being the prerequisite for radiation risk calculations, it is necessary to understand the character of the radiation environment both in- and outside of the ISS as well as the relevant contributions from the radiation field to the organ doses. In this paper the three-dimensional Monte Carlo Particle and Heavy Ion Transport code System (PHITS) and a voxel-based numerical human model NUNDO (Numerical RANDO) were used to estimate the radiation load of human organs during a long term activity outside the ISS. The baseline measured data was generated with the MATROSHKA-1 (MTR-1) experiment taking place from February 2004 up to October 2005 outside the Russian Zvezda module of the ISS, thereby simulating a long term extravehicular activity (EVA) of an astronaut. The organ absorbed dose values calculated by PHITS for the inner organs are in a good agreement with the experimental data. However, a rather large disagreement was observed for the most outer organs. This disagreement appears to be due to the strong dependence that the thickness of the applied carbon fiber container, acting as the EVA suit of the astronaut, has on the effects caused by the trapped electron (TE) component. The organ dose equivalent values for the deeper organs are a factor of two lower than the experimental data. The detailed reason behind this is still under investigation.

  14. Comparison of EGS5 Simulations with Experiment

    SciTech Connect

    Nelson, W.Ralph; Field, Clive; /SLAC

    2006-12-01

    Simulations, made using EGS5, of the longitudinal and radial distributions of energy deposition of electrons of various energies are compared with experimental results in the literature. Energies and materials are: 1 GeV in water and aluminum; 6 GeV in aluminum, copper and lead; and (longitudinal only) 28.5 GeV in alumina (Al{sub 2}O{sub 3}). There is general agreement within a few percent over most of the shower profile. Substantial discrepancies are noted at depths far beyond shower maximum, reaching {approx}30-50% in the cases of lead and copper at 6 GeV.

  15. Phonocatalysis. An ab initio simulation experiment

    SciTech Connect

    Kim, Kwangnam; Kaviany, Massoud

    2016-06-15

    Using simulations, we postulate and show that heterocatalysis on large-bandgap semiconductors can be controlled by substrate phonons, i.e., phonocatalysis. With ab initio calculations, including molecular dynamic simulations, the chemisorbed dissociation of XeF{sub 6} on h-BN surface leads to formation of XeF{sub 4} and two surface F/h-BN bonds. The reaction pathway and energies are evaluated, and the sorption and reaction emitted/absorbed phonons are identified through spectral analysis of the surface atomic motion. Due to large bandgap, the atomic vibration (phonon) energy transfer channels dominate and among them is the match between the F/h-BN covalent bond stretching and the optical phonons. We show that the chemisorbed dissociation (the pathway activation ascent) requires absorption of large-energy optical phonons. Then using progressively heavier isotopes of B and N atoms, we show that limiting these high-energy optical phonons inhibits the chemisorbed dissociation, i.e., controllable phonocatalysis.

  16. Plasma arc cutting technology: simulation and experiments

    NASA Astrophysics Data System (ADS)

    Cantoro, G.; Colombo, V.; Concetti, A.; Ghedini, E.; Sanibondi, P.; Zinzani, F.; Rotundo, F.; Dallavalle, S.; Vancini, M.

    2011-01-01

    Transferred arc plasma torches are widely used in industrial processes for cutting of metallic materials because of their ability to cut a wide range of metals with very high productivity. The process is characterized by a transferred electric arc established between an electrode inside the torch (the cathode) and another electrode, the metallic workpiece to be cut (the anode). In order to obtain a high quality cut and a high productivity, the plasma jet must be as collimated as possible and must have the higher achievable power density. Plasma modelling and numerical simulation can be very useful tools for the designing and optimizing these devices, but research is still in the making for finding a link between simulation of the plasma arc and a consistent prevision of cut quality. Numerical modelling of the behaviour of different types of transferred arc dual gas plasma torches can give an insight on the physical reasons for the industrial success of various design and process solutions that have appeared over the last years. Diagnostics based on high speed imaging and Schlieren photography can play an important role for investigating piercing, dross generation, pilot arcing and anode attachment location. Also, the behaviour of hafnium cathodes at high current levels at the beginning of their service life can been experimentally investigated, with the final aim of understanding the phenomena that take place during those initial piercing and cutting phases and optimizing the initial shape of the surface of the emissive insert exposed to plasma atmosphere.

  17. Tunable nonlinear superconducting metamaterials: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Trepanier, Melissa

    I present experimental and numerical simulation results for two types of nonlinear tunable superconducting metamaterials: 2D arrays of rf SQUIDs (radio frequency superconducting quantum interference devices) as magnetic metamaterials and arrays of Josephson junction-loaded wires as electric metamaterials. The effective inductance of a Josephson junction is sensitive to dc current, temperature, and rf current. I took advantage of this property to design arrays of Josephson junction-loaded wires that present a tunable cutoff frequency and thus a tunable effective permittivity for propagating electromagnetic waves in a one-conductor waveguide. I measured the response of the metamaterial to each tuning parameter and found agreement with numerical simulations that employ the RCSJ (resistively and capacitively shunted junction) model. An rf SQUID is an analogue of an SRR (split ring resonator) with the gap capacitance replaced with a Josephson junction. Like the SRR the SQUID is a resonant structure with a frequency-dependent effective permeability. The difference between the SQUID and the SRR is that the effective inductance and thus effective permeability of the SQUID can be tuned with dc and rf flux, and temperature. Individual rf SQUID meta-atoms and two-dimensional arrays were designed and measured as a function of each tuning parameter and I have found excellent agreement with numerical simulations. There is also an interesting transparency feature that occurs for intermediate rf flux values. The tuning of SQUID arrays has a similar character to the tuning of individual rf SQUID meta-atoms. However, I found that the coupling between the SQUIDs increases the resonant frequency, decreases dc flux tuning, and introduces additional resonant modes. Another feature of arrays is disorder which suppresses the coherence of the response and negatively impacts the emergent properties of the metamaterial. The disorder was experimentally found to be mainly due to a dc flux

  18. Solution to the indexing problem of frequency domain simulation experiments

    NASA Technical Reports Server (NTRS)

    Mitra, Mousumi; Park, Stephen K.

    1991-01-01

    A frequency domain simulation experiment is one in which selected system parameters are oscillated sinusoidally to induce oscillations in one or more system statistics of interest. A spectral (Fourier) analysis of these induced oscillations is then performed. To perform this spectral analysis, all oscillation frequencies must be referenced to a common, independent variable - an oscillation index. In a discrete-event simulation, the global simulation clock is the most natural choice for the oscillation index. However, past efforts to reference all frequencies to the simulation clock generally yielded unsatisfactory results. The reason for these unsatisfactory results is explained in this paper and a new methodology which uses the simulation clock as the oscillation index is presented. Techniques for implementing this new methodology are demonstrated by performing a frequency domain simulation experiment for a network of queues.

  19. Josephson Junction Arrays with Positional Disorder: Experiments and Simulations

    DTIC Science & Technology

    1988-02-01

    Caislinuo an loe*@*. old* it no.ee.q Aid taoncitI y IOcA flMwb~wJ Josephson junctions Positional disorder Monta Carlo simulations 20. AUSTRACT (Conoidiie an...both experiments and Monte Carlo siimulations. We have fabricated 50 x 50 arrays of Pb/Cu proximity-effect junctions, with controlled positional...However, our experiments show no evidence for the predicted reentrant phase transition. Our Monte Carlo simulations of XY spin systems with positional

  20. Simulation of the Viking biology experiments: an overview.

    PubMed

    Klein, H P

    1979-12-01

    Several ground-based investigations have been carried out since the Viking biology results were received from Mars. Many of these have resulted in reasonable simulations of the Martian data, using as analogues of Mars either strong oxidants, UV-treated materials, iron-containing clays, or iron salts. The ambiguity between the GCMS experiment, in which no organic compounds were found on Mars, and the Labeled Release experiment, in which added organics were decomposed, may well be accounted for by these simulations.

  1. Magnetized laboratory plasma jets: experiment and simulation.

    PubMed

    Schrafel, Peter; Bell, Kate; Greenly, John; Seyler, Charles; Kusse, Bruce

    2015-01-01

    Experiments involving radial foils on a 1 MA, 100 ns current driver can be used to study the ablation of thin foils and liners, produce extreme conditions relevant to laboratory astrophysics, and aid in computational code validation. This research focuses on the initial ablation phase of a 20 μm Al foil (8111 alloy), in a radial configuration, driven by Cornell University's COBRA pulsed power generator. In these experiments ablated surface plasma (ASP) on the top side of the foil and a strongly collimated axial plasma jet are observed developing midway through the current rise. With experimental and computational results this work gives a detailed description of the role of the ASP in the formation of the plasma jet with and without an applied axial magnetic field. This ∼1 T field is applied by a Helmholtz-coil pair driven by a slow, 150 μs current pulse and penetrates the load hardware before arrival of the COBRA pulse. Several effects of the applied magnetic field are observed: (1) without the field extreme-ultraviolet emission from the ASP shows considerable azimuthal asymmetry while with the field the ASP develops azimuthal motion that reduces this asymmetry, (2) this azimuthal motion slows the development of the jet when the field is applied, and (3) with the magnetic field the jet becomes less collimated and has a density minimum (hollowing) on the axis. PERSEUS, an XMHD code, has qualitatively and quantitatively reproduced all these experimental observations. The differences between this XMHD and an MHD code without a Hall current and inertial effects are discussed. In addition the PERSEUS results describe effects we were not able to resolve experimentally and suggest a line of future experiments with better diagnostics.

  2. Designing Nursing Simulation Clinical Experiences to Promote Critical Inquiry

    ERIC Educational Resources Information Center

    Beattie, Bev; Koroll, Donna; Price, Susan

    2010-01-01

    The use of high fidelity simulation (HFS) learning opportunities in nursing education has received increased attention in the literature. This article describes the design of a systematic framework used to promote critical inquiry and provide meaningful simulation clinical experiences for second year nursing students. Critical inquiry, as defined…

  3. Computer Simulation of Laboratory Experiments: An Unrealized Potential.

    ERIC Educational Resources Information Center

    Magin, D. J.; Reizes, J. A.

    1990-01-01

    Discussion of the use of computer simulation for laboratory experiments in undergraduate engineering education focuses on work at the University of New South Wales in the instructional design and software development of a package simulating a heat exchange device. The importance of integrating theory, design, and experimentation is also discussed.…

  4. Optimizing Chromatographic Separation: An Experiment Using an HPLC Simulator

    ERIC Educational Resources Information Center

    Shalliker, R. A.; Kayillo, S.; Dennis, G. R.

    2008-01-01

    Optimization of a chromatographic separation within the time constraints of a laboratory session is practically impossible. However, by employing a HPLC simulator, experiments can be designed that allow students to develop an appreciation of the complexities involved in optimization procedures. In the present exercise, a HPLC simulator from "JCE…

  5. Computer Simulation of the Population Growth (Schizosaccharomyces Pombe) Experiment.

    ERIC Educational Resources Information Center

    Daley, Michael; Hillier, Douglas

    1981-01-01

    Describes a computer program (available from authors) developed to simulate "Growth of a Population (Yeast) Experiment." Students actively revise the counting techniques with realistically simulated haemocytometer or eye-piece grid and are reminded of the necessary dilution technique. Program can be modified to introduce such variables…

  6. Optimizing Chromatographic Separation: An Experiment Using an HPLC Simulator

    ERIC Educational Resources Information Center

    Shalliker, R. A.; Kayillo, S.; Dennis, G. R.

    2008-01-01

    Optimization of a chromatographic separation within the time constraints of a laboratory session is practically impossible. However, by employing a HPLC simulator, experiments can be designed that allow students to develop an appreciation of the complexities involved in optimization procedures. In the present exercise, a HPLC simulator from "JCE…

  7. Theory, Image Simulation, and Data Analysis of Chemical Release Experiments

    NASA Technical Reports Server (NTRS)

    Wescott, Eugene M.

    1994-01-01

    The final phase of Grant NAG6-1 involved analysis of physics of chemical releases in the upper atmosphere and analysis of data obtained on previous NASA sponsored chemical release rocket experiments. Several lines of investigation of past chemical release experiments and computer simulations have been proceeding in parallel. This report summarizes the work performed and the resulting publications. The following topics are addressed: analysis of the 1987 Greenland rocket experiments; calculation of emission rates for barium, strontium, and calcium; the CRIT 1 and 2 experiments (Collisional Ionization Cross Section experiments); image calibration using background stars; rapid ray motions in ionospheric plasma clouds; and the NOONCUSP rocket experiments.

  8. Theory, Image Simulation, and Data Analysis of Chemical Release Experiments

    SciTech Connect

    Wescott, E.M.

    1994-04-01

    The final phase of Grant NAG6-1 involved analysis of physics of chemical releases in the upper atmosphere and analysis of data obtained on previous NASA sponsored chemical release rocket experiments. Several lines of investigation of past chemical release experiments and computer simulations have been proceeding in parallel. This report summarizes the work performed and the resulting publications. The following topics are addressed: analysis of the 1987 Greenland rocket experiments; calculation of emission rates for barium, strontium, and calcium; the CRIT 1 and 2 experiments (Collisional Ionization Cross Section experiments); image calibration using background stars; rapid ray motions in ionospheric plasma clouds; and the NOONCUSP rocket experiments.

  9. Simulation of physiology experiments--an alternative to animal use.

    PubMed

    Nageswari, K Sri; Devi, M Syamala; Sharma, Rajeev

    2007-01-01

    Amphibian experiments on nerve-muscle preparation and heart are essential as per first year MBBS practical syllabus, for learning basic concepts in Physiology. Need was felt to design and develop computer based simulation software as an alternative to animal use, due to growing concern and stringent laws imposed by animal ethical bodies. Computer algorithms were developed for 13 amphibian experiments, by manually tracing the graphs obtained through mechanical experimentation and storing the X, Y coordinates for the end points of each line segment as data base tables. By retrieving the data base tables, one for each experiment, the computer simulated graphs were drawn using Visual Basic 6 with timer control and Macromedia Flash for animation effects. A CD-ROM consisting of the software for computer simulation of all the amphibian experiments, as an alternative to the conventional animal experiments, has been developed for the benefit of medical students across the country, as a useful active learning tool.

  10. Simulating CO baseline abundances and pollution events during TRACE-P: How well can we expect to match observations?

    NASA Astrophysics Data System (ADS)

    Hsu, J.; Prather, M.

    2002-12-01

    Observations of CO abundance made along TRACE-P flights in the western Pacific off the coast of Asia (3 Mar - 3 Apr 2001) provide a valuable test for chemistry-transport models (CTMs). We compare these observations with the simulated CO from the UCI chemistry-transport model driven by high-resolution T63L40 meteorological fields from the Oslo/EC model. Several criteria are used to describe the accuracy of the simulation, ranging from probability distributions, to spatial structures, to point-by-point errors. Our focus is on the sensitivity of the overall goodness-of-fit to possible model errors involving boundary layer mixing, convective transport, frontal passage, and of course the emission patterns. We show how such model errors might improve or degrade the goodness-of-fit. Conversely, the 4-D model simulation of CO when sampled along the TRACE-P flight tracks provides a measure of sampling bias and allows us to examine how well the TRACE-P CO data represented the western Pacific at the time. We acknowledge the support and contributions of all our TRACE-P colleagues, particularly for CO measurements (G. Sachse) and CTM development (J. Sundet, O. Wild).

  11. PHITS simulations of the Matroshka experiment

    NASA Astrophysics Data System (ADS)

    Gustafsson, K.; Sihver, L.; Mancusi, D.; Sato, T.; Reitz, G.; Berger, T.

    2010-11-01

    The radiation environment in space is very different from the one encountered on Earth. In addition to the sparsely ionizing radiation, there are particles of different Z with energies ranging from keV up to hundreds of GeV which can cause severe damage to both electronics and humans. It is therefore important to understand the interactions of these highly ionizing particles with different materials such as the hull of space vehicles, human organs and electronics. We have used the Particle and Heavy-Ion Transport code System (PHITS), which is a three-dimensional Monte Carlo code able to calculate interactions and transport of particles and heavy ions with energies up to 100 GeV/nucleon in most matter. PHITS is developed and maintained by a collaboration between RIST (Research Organization for Information Science & Technology), JAEA (Japan Atomic Energy Agency), KEK (High Energy Accelerator Research Organization), Japan and Chalmers University of Technology, Sweden. For the purpose of examining the applicability of PHITS to the shielding design we have simulated the ESA facility Matroshka (MTR) designed and lead by the German Aerospace Center (DLR). Preliminary results are presented and discussed in this paper.

  12. Precision Selenodesy via Differential Very-Long-Baseline Interferometry. Ph.D. Thesis; [Apollo lunar surface experiments package

    NASA Technical Reports Server (NTRS)

    King, R. W., Jr.

    1975-01-01

    The technique of differential very-long baseline interferometry was used to measure the relative positions of the ALSEP transmitters at the Apollo 12, 14, 15, 16, and 17 lunar landing sites with uncertainties less than 0.005 of geocentric arc. These measurements yielded improved determinations of the selenodetic coordinates of the Apollo landing sites, and of the physical libration of the moon. By means of a new device, the differential Doppler receiver (DDR), instrumental errors were reduced to less than the equivalent of 0.001. DDRs were installed in six stations of the NASA spaceflight tracking and data network and used in an extensive program of observations beginning in March 1973.

  13. Development of a neuropsychological battery for the Leukoaraiosis and Disability in the Elderly Study (LADIS): experience and baseline data.

    PubMed

    Madureira, Sofia; Verdelho, Ana; Ferro, José; Basile, Anna-Maria; Chabriat, Hugues; Erkinjuntti, Timo; Fazekas, Franz; Hennerici, Michael; O'brien, John; Pantoni, Leonardo; Salvadori, Emilia; Scheltens, Philip; Visser, Marieke C; Wahlund, Lars-Olof; Waldemar, Gunhild; Wallin, Anders; Inzitari, Domenico

    2006-01-01

    The relationship between age-related white matter changes and cognitive performance in independent elderly people is still not clear. The Leukoaraiosis and Disability in the Elderly study (LADIS) involves 11 European centers. It aims to assess the role of the age-related white matter changes as an independent factor in the transition to disability, and in cognitive performance of an independent elderly population. A comprehensive neuropsychological battery was constructed in order to harmonize the cognitive assessment across countries. Patients were evaluated at baseline and during the 3-year follow-up with the Mini-Mental State Examination, a modified version of the VADAS-Cog (Alzheimer's Dementia Assessment Scale plus tests of Delayed recall, Symbol digit, Digit span, Maze, Digit cancellation and Verbal fluency), Trail making and Stroop test. Six hundred thirty-eight patients (mean age 74 +/- 5 years; mean educational level 10 +/- 4, F/M: 351/287) were included in this study. Neuropsychological data were analyzed test by test and also grouped in three compound measures (executive, memory and speed/motor control domains). Older subjects (>74 years) performed significantly worse than younger subjects on the ADAS-Mod and on the tests of memory (t(631) = 3.25; p = 0.001), executive functions (t(581) = 4.68; p = 0.001) and speed/motor control (t(587) = 4.01; p = 0.001). Participants with higher educational level (>8 years of school) showed better performances on the compound measures for memory (t(631) = 3.25; p = 0.001), executive functions (t(581) = 4.68; p = 0.001) and speed/motor control (t(587) = 4.01; p = 0.001). Using multiple regression analysis models to study the influence of demographic variables on cognitive performance, age and education remained important variables influencing test performance. In the LADIS population baseline data, older age and lower educational levels negatively influence neuropsychological performance.

  14. Modeling and Simulation of Fluid Mixing Laser Experiments and Supernova

    SciTech Connect

    James Glimm

    2009-06-04

    The three year plan for this project was to develop novel theories and advanced simulation methods leading to a systematic understanding of turbulent mixing. A primary focus is the comparison of simulation models (Direct Numerical Simulation (DNS), Large Eddy Simulations (LES), full two fluid simulations and subgrid averaged models) to experiments. The comprehension and reduction of experimental and simulation data are central goals of this proposal. We model 2D and 3D perturbations of planar or circular interfaces. We compare these tests with models derived from averaged equations (our own and those of others). As a second focus, we develop physics based subgrid simulation models of diffusion across an interface, with physical but no numerical mass diffusion. Multiple layers and reshock are considered here.

  15. Mixed reality ventriculostomy simulation: experience in neurosurgical residency.

    PubMed

    Hooten, Kristopher G; Lister, J Richard; Lombard, Gwen; Lizdas, David E; Lampotang, Samsun; Rajon, Didier A; Bova, Frank; Murad, Gregory J A

    2014-12-01

    Medicine and surgery are turning toward simulation to improve on limited patient interaction during residency training. Many simulators today use virtual reality with augmented haptic feedback with little to no physical elements. In a collaborative effort, the University of Florida Department of Neurosurgery and the Center for Safety, Simulation & Advanced Learning Technologies created a novel "mixed" physical and virtual simulator to mimic the ventriculostomy procedure. The simulator contains all the physical components encountered for the procedure with superimposed 3-D virtual elements for the neuroanatomical structures. To introduce the ventriculostomy simulator and its validation as a necessary training tool in neurosurgical residency. We tested the simulator in more than 260 residents. An algorithm combining time and accuracy was used to grade performance. Voluntary postperformance surveys were used to evaluate the experience. Results demonstrate that more experienced residents have statistically significant better scores and completed the procedure in less time than inexperienced residents. Survey results revealed that most residents agreed that practice on the simulator would help with future ventriculostomies. This mixed reality simulator provides a real-life experience, and will be an instrumental tool in training the next generation of neurosurgeons. We have now implemented a standard where incoming residents must prove efficiency and skill on the simulator before their first interaction with a patient.

  16. Simulation of the GEM detector for BM@N experiment

    NASA Astrophysics Data System (ADS)

    Baranov, Dmitriy; Rogachevsky, Oleg

    2017-03-01

    The Gas Electron Multiplier (GEM) detector is one of the basic parts of the BM@N experiment included in the NICA project. The simulation model that takes into account features of signal generation process in an ionization GEM chamber is presented in this article. Proper parameters for the simulation were extracted from data retrieved with the help of Garfield++ (a toolkit for the detailed simulation of particle detectors). Due to this, we are able to generate clusters in layers of the micro-strip readout that correspond to clusters retrieved from a real physics experiment.

  17. Sensitivity of ocean carbon uptake to baseline ocean simulation and circulation, interior biogeochemistry, and sediment calcite feedbacks

    NASA Astrophysics Data System (ADS)

    Dunne, J. P.; John, J. G.

    2012-12-01

    We assess the ocean's present and future ability to take up anthropogenic carbon and the impact of this ocean acidification in the fully coupled biogeochemical context using NOAA/GFDL's earth system models (ESM2M and ESM2G) with alternative representation of ocean physics, but the same ocean biogeochemical component. The models were forced with historical and future projections of Representative Concentration Pathways (RCPs) of radiatively active gases as part of the fifth Coupled Model Intercomparison Project. We describe the geographical and vertical extent of ocean acidification in these models, finding approximately 10% more rapid CO2 uptake in the z-coordinate ESM2M than isopycnal ESM2G attributable to differences in their baseline thermocline structure and resulting excess alkalinity. The circulation response to climate forcing, however, is found to be extremely similar between these models as reduction in overturning circulation leads to diminished tropical upwelling and corresponding redistribution of properties. The net effect is a loss of approximately 10 PgC in the IndoPacific, and gain of 10PgC in the Southern Ocean. Enhanced stratification under climate warming also enhances the efficiency of the biological pump, but the net effect of this on carbon uptake is neutralized by the corresponding reduction in solubility. Modeled calcite and aragonite production is strongly depressed by ocean acidification. These responses provide additional acid neutralizing capacity in the surface ocean, but of less than order 1 PgC a-1. Associated changes in the mineral ballasting of sinking organic material combine with enhanced physical stratification to shoal the remineralization of organic material. We find that acidification also leads to enhanced dissolution of sediment calcite, but also of less than order 1 PgC a-1.

  18. "FluSpec": A Simulated Experiment in Fluorescence Spectroscopy

    ERIC Educational Resources Information Center

    Bigger, Stephen W.; Bigger, Andrew S.; Ghiggino, Kenneth P.

    2014-01-01

    The "FluSpec" educational software package is a fully contained tutorial on the technique of fluorescence spectroscopy as well as a simulator on which experiments can be performed. The procedure for each of the experiments is also contained within the package along with example analyses of results that are obtained using the software.

  19. "FluSpec": A Simulated Experiment in Fluorescence Spectroscopy

    ERIC Educational Resources Information Center

    Bigger, Stephen W.; Bigger, Andrew S.; Ghiggino, Kenneth P.

    2014-01-01

    The "FluSpec" educational software package is a fully contained tutorial on the technique of fluorescence spectroscopy as well as a simulator on which experiments can be performed. The procedure for each of the experiments is also contained within the package along with example analyses of results that are obtained using the software.

  20. Experiences with linear solvers for oil reservoir simulation problems

    SciTech Connect

    Joubert, W.; Janardhan, R.; Biswas, D.; Carey, G.

    1996-12-31

    This talk will focus on practical experiences with iterative linear solver algorithms used in conjunction with Amoco Production Company`s Falcon oil reservoir simulation code. The goal of this study is to determine the best linear solver algorithms for these types of problems. The results of numerical experiments will be presented.

  1. Simulation ensemble for a laser–driven shear experiment

    SciTech Connect

    Haines, Brian M.; Grinstein, Fernando F.; Welser–Sherrill, Leslie; Fincke, James R.; Doss, Forrest W.

    2013-09-15

    We perform an ensemble of simulations of a laser-driven shear experiment [L. Welser-Sherrill et al., “Two laser-driven mix experiments to study reshock and shear,” High Energy Density Phys. J. 9(3), 496–499 (2013)] in the strong-shock high energy-density regime to better understand material mixing driven by the Kelvin–Helmholtz instability. Each simulation uses a different realization of random initial interface perturbations based on data from targets used in experiments. Validation of the simulations is based on direct comparison of simulation and radiographic data. Simulations are also compared with published direct numerical simulation and the theory of homogeneous isotropic turbulence. Despite the fact that the flow is neither homogeneous, isotropic, nor fully turbulent, there are local regions in which the flow demonstrates characteristics of homogeneous isotropic turbulence. Our analysis shows characteristics consistent with those of incompressible isotropic turbulence. Our results show that turbulent features are present both near the shock front and in a separated region in the wake of the shock. These features develop and decay at different rates. Finally, we use the ensemble of three-dimensional simulations to test the performance of two-dimensional Reynolds-averaged Navier-Stokes simulations. In this context, we also test a presumed probability density function turbulent mixing model extensively used in combustion applications.

  2. Analysis of a DNA simulation model through hairpin melting experiments

    PubMed Central

    Linak, Margaret C.; Dorfman, Kevin D.

    2010-01-01

    We compare the predictions of a two-bead Brownian dynamics simulation model to melting experiments of DNA hairpins with complementary AT or GC stems and noninteracting loops in buffer A. This system emphasizes the role of stacking and hydrogen bonding energies, which are characteristics of DNA, rather than backbone bending, stiffness, and excluded volume interactions, which are generic characteristics of semiflexible polymers. By comparing high throughput data on the open-close transition of various DNA hairpins to the corresponding simulation data, we (1) establish a suitable metric to compare the simulations to experiments, (2) find a conversion between the simulation and experimental temperatures, and (3) point out several limitations of the model, including the lack of G-quartets and cross stacking effects. Our approach and experimental data can be used to validate similar coarse-grained simulation models. PMID:20886965

  3. Synthetic Vision Systems - Operational Considerations Simulation Experiment

    NASA Technical Reports Server (NTRS)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-01-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents/accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  4. Synthetic vision systems: operational considerations simulation experiment

    NASA Astrophysics Data System (ADS)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-04-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  5. Simulations of Ground and Space-Based Oxygen Atom Experiments

    NASA Technical Reports Server (NTRS)

    Finchum, A. (Technical Monitor); Cline, J. A.; Minton, T. K.; Braunstein, M.

    2003-01-01

    A low-earth orbit (LEO) materials erosion scenario and the ground-based experiment designed to simulate it are compared using the direct-simulation Monte Carlo (DSMC) method. The DSMC model provides a detailed description of the interactions between the hyperthermal gas flow and a normally oriented flat plate for each case. We find that while the general characteristics of the LEO exposure are represented in the ground-based experiment, multi-collision effects can potentially alter the impact energy and directionality of the impinging molecules in the ground-based experiment. Multi-collision phenomena also affect downstream flux measurements.

  6. Simulations of Ground and Space-Based Oxygen Atom Experiments

    NASA Technical Reports Server (NTRS)

    Finchum, A. (Technical Monitor); Cline, J. A.; Minton, T. K.; Braunstein, M.

    2003-01-01

    A low-earth orbit (LEO) materials erosion scenario and the ground-based experiment designed to simulate it are compared using the direct-simulation Monte Carlo (DSMC) method. The DSMC model provides a detailed description of the interactions between the hyperthermal gas flow and a normally oriented flat plate for each case. We find that while the general characteristics of the LEO exposure are represented in the ground-based experiment, multi-collision effects can potentially alter the impact energy and directionality of the impinging molecules in the ground-based experiment. Multi-collision phenomena also affect downstream flux measurements.

  7. Monte Carlo Strategies for Selecting Parameter Values in Simulation Experiments.

    PubMed

    Leigh, Jessica W; Bryant, David

    2015-09-01

    Simulation experiments are used widely throughout evolutionary biology and bioinformatics to compare models, promote methods, and test hypotheses. The biggest practical constraint on simulation experiments is the computational demand, particularly as the number of parameters increases. Given the extraordinary success of Monte Carlo methods for conducting inference in phylogenetics, and indeed throughout the sciences, we investigate ways in which Monte Carlo framework can be used to carry out simulation experiments more efficiently. The key idea is to sample parameter values for the experiments, rather than iterate through them exhaustively. Exhaustive analyses become completely infeasible when the number of parameters gets too large, whereas sampled approaches can fare better in higher dimensions. We illustrate the framework with applications to phylogenetics and genetic archaeology.

  8. Visualizing Hyporheic Flow Through Bedforms Using Dye Experiments and Simulation.

    PubMed

    Stonedahl, Susa H; Roche, Kevin R; Stonedahl, Forrest; Packman, Aaron I

    2015-11-18

    Advective exchange between the pore space of sediments and the overlying water column, called hyporheic exchange in fluvial environments, drives solute transport in rivers and many important biogeochemical processes. To improve understanding of these processes through visual demonstration, we created a hyporheic flow simulation in the multi-agent computer modeling platform NetLogo. The simulation shows virtual tracer flowing through a streambed covered with two-dimensional bedforms. Sediment, flow, and bedform characteristics are used as input variables for the model. We illustrate how these simulations match experimental observations from laboratory flume experiments based on measured input parameters. Dye is injected into the flume sediments to visualize the porewater flow. For comparison virtual tracer particles are placed at the same locations in the simulation. This coupled simulation and lab experiment has been used successfully in undergraduate and graduate laboratories to directly visualize river-porewater interactions and show how physically-based flow simulations can reproduce environmental phenomena. Students took photographs of the bed through the transparent flume walls and compared them to shapes of the dye at the same times in the simulation. This resulted in very similar trends, which allowed the students to better understand both the flow patterns and the mathematical model. The simulations also allow the user to quickly visualize the impact of each input parameter by running multiple simulations. This process can also be used in research applications to illustrate basic processes, relate interfacial fluxes and porewater transport, and support quantitative process-based modeling.

  9. Natural streamflow simulation for two largest river basins in Poland: a baseline for identification of flow alterations

    NASA Astrophysics Data System (ADS)

    Piniewski, Mikołaj

    2016-05-01

    The objective of this study was to apply a previously developed large-scale and high-resolution SWAT model of the Vistula and the Odra basins, calibrated with the focus of natural flow simulation, in order to assess the impact of three different dam reservoirs on streamflow using the Indicators of Hydrologic Alteration (IHA). A tailored spatial calibration approach was designed, in which calibration was focused on a large set of relatively small non-nested sub-catchments with semi-natural flow regime. These were classified into calibration clusters based on the flow statistics similarity. After performing calibration and validation that gave overall positive results, the calibrated parameter values were transferred to the remaining part of the basins using an approach based on hydrological similarity of donor and target catchments. The calibrated model was applied in three case studies with the purpose of assessing the effect of dam reservoirs (Włocławek, Siemianówka and Czorsztyn Reservoirs) on streamflow alteration. Both the assessment based on gauged streamflow (Before-After design) and the one based on simulated natural streamflow showed large alterations in selected flow statistics related to magnitude, duration, high and low flow pulses and rate of change. Some benefits of using a large-scale and high-resolution hydrological model for the assessment of streamflow alteration include: (1) providing an alternative or complementary approach to the classical Before-After designs, (2) isolating the climate variability effect from the dam (or any other source of alteration) effect, (3) providing a practical tool that can be applied at a range of spatial scales over large area such as a country, in a uniform way. Thus, presented approach can be applied for designing more natural flow regimes, which is crucial for river and floodplain ecosystem restoration in the context of the European Union's policy on environmental flows.

  10. Impact of detector simulation in particle physics collider experiments

    NASA Astrophysics Data System (ADS)

    Daniel Elvira, V.

    2017-06-01

    Through the last three decades, accurate simulation of the interactions of particles with matter and modeling of detector geometries has proven to be of critical importance to the success of the international high-energy physics (HEP) experimental programs. For example, the detailed detector modeling and accurate physics of the Geant4-based simulation software of the CMS and ATLAS particle physics experiments at the European Center of Nuclear Research (CERN) Large Hadron Collider (LHC) was a determinant factor for these collaborations to deliver physics results of outstanding quality faster than any hadron collider experiment ever before. This review article highlights the impact of detector simulation on particle physics collider experiments. It presents numerous examples of the use of simulation, from detector design and optimization, through software and computing development and testing, to cases where the use of simulation samples made a difference in the precision of the physics results and publication turnaround, from data-taking to submission. It also presents estimates of the cost and economic impact of simulation in the CMS experiment. Future experiments will collect orders of magnitude more data with increasingly complex detectors, taxing heavily the performance of simulation and reconstruction software. Consequently, exploring solutions to speed up simulation and reconstruction software to satisfy the growing demand of computing resources in a time of flat budgets is a matter that deserves immediate attention. The article ends with a short discussion on the potential solutions that are being considered, based on leveraging core count growth in multicore machines, using new generation coprocessors, and re-engineering HEP code for concurrency and parallel computing.

  11. Impact of detector simulation in particle physics collider experiments

    DOE PAGES

    Elvira, V. Daniel

    2017-06-01

    Through the last three decades, precise simulation of the interactions of particles with matter and modeling of detector geometries has proven to be of critical importance to the success of the international high-energy physics experimental programs. For example, the detailed detector modeling and accurate physics of the Geant4-based simulation software of the CMS and ATLAS particle physics experiments at the European Center of Nuclear Research (CERN) Large Hadron Collider (LHC) was a determinant factor for these collaborations to deliver physics results of outstanding quality faster than any hadron collider experiment ever before. This review article highlights the impact of detectormore » simulation on particle physics collider experiments. It presents numerous examples of the use of simulation, from detector design and optimization, through software and computing development and testing, to cases where the use of simulation samples made a difference in the accuracy of the physics results and publication turnaround, from data-taking to submission. It also presents the economic impact and cost of simulation in the CMS experiment. Future experiments will collect orders of magnitude more data, taxing heavily the performance of simulation and reconstruction software for increasingly complex detectors. Consequently, it becomes urgent to find solutions to speed up simulation software in order to cope with the increased demand in a time of flat budgets. The study ends with a short discussion on the potential solutions that are being explored, by leveraging core count growth in multicore machines, using new generation coprocessors, and re-engineering of HEP code for concurrency and parallel computing.« less

  12. GFDL's ESM2 global coupled climate-carbon Earth System Models. Part I: physical formulation and baseline simulation characteristics

    USGS Publications Warehouse

    Dunne, John P.; John, Jasmin G.; Adcroft, Alistair J.; Griffies, Stephen M.; Hallberg, Robert W.; Shevalikova, Elena; Stouffer, Ronald J.; Cooke, William; Dunne, Krista A.; Harrison, Matthew J.; Krasting, John P.; Malyshev, Sergey L.; Milly, P.C.D.; Phillipps, Peter J.; Sentman, Lori A.; Samuels, Bonita L.; Spelman, Michael J.; Winton, Michael; Wittenberg, Andrew T.; Zadeh, Niki

    2012-01-01

    We describe the physical climate formulation and simulation characteristics of two new global coupled carbon-climate Earth System Models, ESM2M and ESM2G. These models demonstrate similar climate fidelity as the Geophysical Fluid Dynamics Laboratory's previous CM2.1 climate model while incorporating explicit and consistent carbon dynamics. The two models differ exclusively in the physical ocean component; ESM2M uses Modular Ocean Model version 4.1 with vertical pressure layers while ESM2G uses Generalized Ocean Layer Dynamics with a bulk mixed layer and interior isopycnal layers. Differences in the ocean mean state include the thermocline depth being relatively deep in ESM2M and relatively shallow in ESM2G compared to observations. The crucial role of ocean dynamics on climate variability is highlighted in the El Niño-Southern Oscillation being overly strong in ESM2M and overly weak ESM2G relative to observations. Thus, while ESM2G might better represent climate changes relating to: total heat content variability given its lack of long term drift, gyre circulation and ventilation in the North Pacific, tropical Atlantic and Indian Oceans, and depth structure in the overturning and abyssal flows, ESM2M might better represent climate changes relating to: surface circulation given its superior surface temperature, salinity and height patterns, tropical Pacific circulation and variability, and Southern Ocean dynamics. Our overall assessment is that neither model is fundamentally superior to the other, and that both models achieve sufficient fidelity to allow meaningful climate and earth system modeling applications. This affords us the ability to assess the role of ocean configuration on earth system interactions in the context of two state-of-the-art coupled carbon-climate models.

  13. Plasma Simulation for the SHIP Experiment at GDT

    SciTech Connect

    Anikeev, A.V.; Bagryansky, P.A.; Collatz, S.; Noack, K

    2005-01-15

    The concept of the Synthesized Hot Ion Plasmoid (SHIP) experiment at the gas dynamic trap (GDT) facility of the Budker Institute Novosibirsk was presented at the 29{sup th} EPS Conference. During the last year several numerical simulations were made by means of the Integrated Transport Code System (ITCS) to determine the best experimental scenario for getting high plasma parameters. This contribution presents important results of the recent numerical simulations of SHIP by means of the ITCS modules.

  14. Computer Simulation of Einstein-Podolsky-Rosen-Bohm Experiments

    NASA Astrophysics Data System (ADS)

    de Raedt, H.; Michielsen, K.

    2016-07-01

    We review an event-based simulation approach which reproduces the statistical distributions of quantum physics experiments by generating detection events one-by-one according to an unknown distribution and without solving a wave equation. Einstein-Podolsky-Rosen-Bohm laboratory experiments are used as an example to illustrate the applicability of this approach. It is shown that computer experiments that employ the same post-selection procedure as the one used in laboratory experiments produce data that is in excellent agreement with quantum theory.

  15. A Very-Short-Baseline Time Transfer Experiment Using Two Geodetic-Quality GPS Receivers and Carrier Phase Techniques

    DTIC Science & Technology

    1998-12-01

    recently purchased Ashtech 212-T receiver and an ol&r AUen Osborne Associates (AOA) TTR- 4P receiver. Data collected from these geodetic-quality GPS...commercial software. In this paper the results of a very-shorkbaseline common-clock experiment between NPL’s Ashtech Z12-T and AOA TTR- 4P geodetic...8217 performance. 2 GEODETIC GPS HARDWARE AT NPL NPL possesses two geodetic quality GPS receivers, an Ashtech Z12-T and an AOrZ TTR- 4P . The hardware

  16. Simulator design for advanced ISDN satellite design and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerald R.

    1992-01-01

    This simulation design task completion report documents the simulation techniques associated with the network models of both the Interim Service ISDN (integrated services digital network) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures. The ISIS network model design represents satellite systems like the Advanced Communication Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) program, moves all control and switching functions on-board the next generation ISDN communication satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete events simulation experiments will be performed with these models using various traffic scenarios, design parameters and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

  17. Crisis in the Belousov--Zhabotinskii reaction: Experiment and simulation

    SciTech Connect

    Richetti, P.; De Kepper, P.; Roux, J.C.; Swinney, H.L.

    1987-09-01

    An abrupt transition that has the character of an interior crisis was observed in an experiment on the Belousov--Zhabotinskii reaction as a control parameter was varied (a crisis is a qualitative change in the dynamics of a system observed when an attractor collides with the stable manifold of a fixed point). The interpretation of the observed behavior as a crisis is corroborated by a numerical analysis of a seven-variable model of the reaction. The waveforms, attractors, and maps obtained in the simulation are remarkably similar to those obtained in the laboratory experiment. The simulation indicates that the crisis is a consequence of a multivalued first return map.

  18. Monte Carlo simulation of the Neutrino-4 experiment

    SciTech Connect

    Serebrov, A. P. Fomin, A. K.; Onegin, M. S.; Ivochkin, V. G.; Matrosov, L. N.

    2015-12-15

    Monte Carlo simulation of the two-section reactor antineutrino detector of the Neutrino-4 experiment is carried out. The scintillation-type detector is based on the inverse beta-decay reaction. The antineutrino is recorded by two successive signals from the positron and the neutron. The simulation of the detector sections and the active shielding is performed. As a result of the simulation, the distributions of photomultiplier signals from the positron and the neutron are obtained. The efficiency of the detector depending on the signal recording thresholds is calculated.

  19. Simulations of NOVA direct-drive hydrodynamics experiments

    SciTech Connect

    Weber, S.V,; Glendinning, S.G.

    1991-04-15

    Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. Foils with single-wavelength imposed surface perturbations have been driven with a single beam of 0.53 {mu}m light, employing smoothing by spectral dispersion (SSD). In addition to simulating foils with imposed surface perturbations, we have simulated flat foils driven by beams with time-dependent intensity modulation resulting from the NOVA implementation of SSD. These simulations show the development of large amplitude modulation of the target from residual intensity nonuniformities. Structure seeded by beam nonuniformity would overwhelm modulation resulting from imposed surface perturbations of sub-micron initial amplitude, but is predicted to develop sufficiently slowly that we expect to observe growth of perturbations with initial amplitudes of several microns. In other NOVA experiments, flat foils with an embedded brominated spectroscopic tracer layer are used in infer mass ablation rates. SSD drive is predicted to yield ablation rates in better agreement with 1-D simulations than drive from a beam with random phase plates (RPP) alone. Simulations of foils driven with RPP beams show enhanced ablation rates because modulation of the ablation front increases its surface area. Line emission from the seed is first seen at cold spots in the beam, which create protruding spikes at the ablation front. Simulation results will be compared with early experimental data. 5 refs., 14 figs.

  20. Numerical Simulation and Cold Modeling experiments on Centrifugal Casting

    NASA Astrophysics Data System (ADS)

    Keerthiprasad, Kestur Sadashivaiah; Murali, Mysore Seetharam; Mukunda, Pudukottah Gopaliengar; Majumdar, Sekhar

    2011-02-01

    In a centrifugal casting process, the fluid flow eventually determines the quality and characteristics of the final product. It is difficult to study the fluid behavior here because of the opaque nature of melt and mold. In the current investigation, numerical simulations of the flow field and visualization experiments on cold models have been carried out for a centrifugal casting system using horizontal molds and fluids of different viscosities to study the effect of different process variables on the flow pattern. The effects of the thickness of the cylindrical fluid annulus formed inside the mold and the effects of fluid viscosity, diameter, and rotational speed of the mold on the hollow fluid cylinder formation process have been investigated. The numerical simulation results are compared with corresponding data obtained from the cold modeling experiments. The influence of rotational speed in a real-life centrifugal casting system has also been studied using an aluminum-silicon alloy. Cylinders of different thicknesses are cast at different rotational speeds, and the flow patterns observed visually in the actual castings are found to be similar to those recorded in the corresponding cold modeling experiments. Reasonable agreement is observed between the results of numerical simulation and the results of cold modeling experiments with different fluids. The visualization study on the hollow cylinders produced in an actual centrifugal casting process also confirm the conclusions arrived at from the cold modeling experiments and numerical simulation in a qualitative sense.

  1. Attitudes of Nurse and Physician trainees towards an interprofessional simulated education experience on Pain Assessment and Management.

    PubMed

    Salam, Tabassum; Saylor, Jennifer L; Cowperthwait, Amy Lynn

    2015-05-01

    An interprofessional group of educators from multiple institutions piloted a simulation-based learning experience focusing on acute pain management. The participants in the program were resident physicians-novice nurse dyads, and medical student-nursing student dyads from large universities and a magnet health care system. Each dyad was challenged to assess and manage acute pain in a simulated hospitalized patient using effective collaboration skills. The simulations included pre-debriefing, simulation, and a debriefing session. Participants completed pre- and post-surveys measuring confidence in pain management and attitudes toward physician-nurse collaboration. There was a significant positive shift in the confidence of the learners' ability to assess and manage acute pain in a hospitalized patient after the simulation and debriefing (23.2% strongly agreed versus 7% at baseline). Participants' attitudes regarding education to enhance interprofessional collaboration improved after the simulation experience (83.9% strongly agreed versus 73.7% at baseline). Based on these encouraging findings, we are extending this interprofessional experience to a larger group of learners with the same targeted dyads.

  2. Initial Experiences with Retrieving Similar Objects in Simulation Data

    SciTech Connect

    Cheung, S-C S; Kamath, C

    2003-02-21

    Comparing the output of a physics simulation with an experiment, referred to as 'code validation,' is often done by visually comparing the two outputs. In order to determine which simulation is a closer match to the experiment, more quantitative measures are needed. In this paper, we describe our early experiences with this problem by considering the slightly simpler problem of finding objects in a image that are similar to a given query object. Focusing on a dataset from a fluid mixing problem, we report on our experiments with different features that are used to represent the objects of interest in the data. These early results indicate that the features must be chosen carefully to correctly represent the query object and the goal of the similarity search.

  3. Measuring the CP-violating phase by a long base-line neutrino experiment with Hyper-Kamiokande

    NASA Astrophysics Data System (ADS)

    Aoki, Mayumi; Hagiwara, Kaoru; Okamura, Naotoshi

    2003-02-01

    We study the sensitivity of a long-base-line (LBL) experiment with neutrino beams from the High Intensity Proton Accelerator (HIPA), that delivers 1021 POT per year, and a proposed 1 Mt water Čerenkov detector, Hyper-Kamiokande (HK) 295 km away from the HIPA, to the CP phase (δMNS) of the three-flavor lepton mixing matrix. We examine a combination of the νμ narrow-band beam (NBB) at two different energies, =2, 3 GeV, and the ν¯μ NBB at =2 GeV. By allocating one year each for the two νμ beams and four years for the ν¯μ beam, we can efficiently measure the νμ→νe and ν¯μ→ν¯e transition probabilities, as well as the νμ and ν¯μ survival probabilities. CP violation in the lepton sector can be established at 4σ (3σ) level if the MSW large-mixing-angle scenario of the solar-neutrino deficit is realized, |δMNS| or |δMNS-180°|>30°, and if 4|Ue3|2(1-|Ue3|2)≡sin22θRCT>0.03 (0.01). The phase δMNS is more difficult to constrain by this experiment if there is little CP violation, δMNS∼0°or 180°, which can be distinguished at 1σ level if sin22θRCT≳0.01.

  4. Simulated Performance of the Orbiting Wide-angle Light Collectors (OWL) Experiment

    NASA Technical Reports Server (NTRS)

    Krizmanic, J. F.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The Orbiting Wide-angle Light collectors (OWL) experiment is in NASA's mid-term strategic plan and will stereoscopically image, from equatorial orbit, the air fluorescence signal generated by airshowers induced by the ultrahigh energy (E greater than few x 10(exp 19) eV) component of the cosmic radiation. The use of a space-based platform enables an extremely large event acceptance aperture and thus will allow a high statistics measurement of these rare events. Detailed Monte Carlo simulations are required to quantify the physics potential of the mission as well as optimize the instrumental parameters. This paper reports on the results of the GSFC Monte Carlo simulation for two different, OWL instrument baseline designs. These results indicate that, assuming a continuation of the cosmic ray spectrum (theta approximately E(exp -2.75), OWL could have an event rate of 4000 events/year with E greater than or equal to 10(exp 20) eV. Preliminary results, based upon these Monte Carlo simulations, indicate that events can be accurately reconstructed in the detector focal plane arrays for the OWL instrument baseline designs under consideration.

  5. Supersonic jet noise prediction and noise source investigation for realistic baseline and chevron nozzles based on hybrid RANS/LES simulations

    NASA Astrophysics Data System (ADS)

    Du, Yongle

    Jet noise simulations have been performed for a military-style baseline nozzle and a chevron nozzle with design Mach numbers of Md = 1:5 operating at several off-design conditions. The objective of the current numerical study is to provide insight into the noise generation mechanisms of shock-containing supersonic hot jets and the noise reduction mechanisms of chevron nozzles. A hybrid methodology combining advanced CFD technologies and the acoustic analogy is used for supersonic jet noise simulations. Unsteady Reynolds-averaged Navier-Stokes (URANS) equations are solved to predict the turbulent noise sources in the jet flows. A modified version of the Detached Eddy Simulation (DES) approach is used to avoid excessive damping of fine scale turbulent fluctuations. A multiblock structured mesh topology is used to represent complex nozzle geometries, including the faceted inner contours and finite nozzle thickness. A block interface condition is optimized for the complex multiblock mesh topology to avoid the centerline singularity. A fourth-order Dispersion-Relation-Preserving (DRP) scheme is used for spatial discretization. To enable efficient calculations, a dual time-stepping method is used in addition to parallel computation using MPI. Both multigrid and implicit residual smoothing are used to accelerate the convergence rate of sub-iterations in the fictitious time domain. Noise predictions are made with the permeable surface Ffowcs Williams and Hawkings (FWH) solution. All the numerical methods have been implemented in the jet flow simulation code "CHOPA" and the noise prediction code "PSJFWH". The computer codes have been validated with several benchmark cases. A preliminary study has been performed for an under-expanded baseline nozzle jet with Mj = 1:56 to validate the accuracy of the jet noise simulations. The results show that grid refinement around the jet potential core and the use of a lower artificial dissipation improve the resolution of the predicted

  6. Inter-task transfer of meaningful, functional skills following a cognitive-based treatment: Results of three multiple baseline design experiments in adults with chronic stroke.

    PubMed

    McEwen, Sara E; Polatajko, Helene J; Huijbregts, Maria P J; Ryan, Jennifer D

    2010-08-01

    The transfer of skills learned in rehabilitation to new skills in the home has hitherto been notoriously difficult to achieve. The Cognitive Orientation to daily Occupational Performance (CO-OP) treatment approach has been associated with improved performance in people living with stroke, but the specific impact on transfer to untrained skills has not been investigated. The objective of the study was to investigate the capacity of CO-OP treatment to improve performance in both trained and untrained self-selected skills in adults living with stroke. A single case experiment with multiple baselines across skills was conducted, with two replications. The participants self-selected four skills; three were trained using CO-OP; the fourth was not. Using video recording, data points were collected at multiple baselines, during intervention, post-intervention, and at follow-up. The Performance Quality Rating Scale (PQRS) was used by an independent rater to score performances. The two-standard deviation band method was used to determine the significance of improvements. At follow-up, significant performance improvements were seen in all three single case experiments in all trained and untrained skills. A cognitive-based approach was associated with improved performance in trained and untrained skills in three adults with chronic stroke; further controlled research is warranted.

  7. New simulation capability for gamma ray mirror experiments

    SciTech Connect

    Descalle, Marie-Anne; Ruz-Armendariz, Jaime; Decker, Todd; Brejhnolt, Nicolai; Pivovaroff, Michael

    2015-09-28

    This report provides a description of the simulation toolkit developed at Lawrence Livermore National Laboratory to support the design of nuclear safeguards experiments using grazing incidence multilayer mirrors in the energy band of uranium (U) and plutonium (Pu) emission lines. This effort was motivated by the data analysis of a scoping experiment at the Irradiated Fuels Examination Facility (IFEL) at Oak Ridge National Laboratory in FY13 and of a benchmark experiment at the Idaho National Laboratory (INL) in FY14 that highlighted the need for predictive tools built around a ray-tracing capability. This report presents the simulation toolkit and relevant results such as the simulated spectra for TMI, MOX, and ATM106 fuel rods based on spent fuel models provided by Los Alamos National Laboratory and for a virgin high 240Pu-content fuel plate, as well as models of the IFEL and INL experiments implemented in the ray tracing tool. The beam position and height were validated against the INL ~60 keV americium data. Examples of alternate configurations of the optics or experimental set-up illustrate the future use of the simulation suite to guide the next IFEL experimental campaign.

  8. Effects of Error Experience When Learning to Simulate Hypernasality

    ERIC Educational Resources Information Center

    Wong, Andus W.-K.; Tse, Andy C.-Y.; Ma, Estella P.-M.; Whitehill, Tara L.; Masters, Rich S. W.

    2013-01-01

    Purpose: The purpose of this study was to evaluate the effects of error experience on the acquisition of hypernasal speech. Method: Twenty-eight healthy participants were asked to simulate hypernasality in either an "errorless learning" condition (in which the possibility for errors was limited) or an "errorful learning"…

  9. Students' Experiences of Learning Manual Clinical Skills through Simulation

    ERIC Educational Resources Information Center

    Johannesson, Eva; Silen, Charlotte; Kvist, Joanna; Hult, Hakan

    2013-01-01

    Learning manual skills is a fundamental part of health care education, and motor, sensory and cognitive learning processes are essential aspects of professional development. Simulator training has been shown to enhance factors that facilitate motor and cognitive learning. The present study aimed to investigate the students' experiences and…

  10. Photovoltaic Experiment Using Light from a Solar Simulator Lamp.

    ERIC Educational Resources Information Center

    Chow, R. H.

    1980-01-01

    A photovoltaic cell experiment utilizing the convenience of a solar simulating type lamp is described. Insight into the solid state aspect of a solar cell is gained by the student in studying the characteristics, and deducing from them cell parameters and efficiency. (Author/CS)

  11. Photovoltaic Experiment Using Light from a Solar Simulator Lamp.

    ERIC Educational Resources Information Center

    Chow, R. H.

    1980-01-01

    A photovoltaic cell experiment utilizing the convenience of a solar simulating type lamp is described. Insight into the solid state aspect of a solar cell is gained by the student in studying the characteristics, and deducing from them cell parameters and efficiency. (Author/CS)

  12. Students' Experiences of Learning Manual Clinical Skills through Simulation

    ERIC Educational Resources Information Center

    Johannesson, Eva; Silen, Charlotte; Kvist, Joanna; Hult, Hakan

    2013-01-01

    Learning manual skills is a fundamental part of health care education, and motor, sensory and cognitive learning processes are essential aspects of professional development. Simulator training has been shown to enhance factors that facilitate motor and cognitive learning. The present study aimed to investigate the students' experiences and…

  13. Experiment and simulation for CSI: What are the missing links?

    NASA Technical Reports Server (NTRS)

    Belvin, W. Keith; Park, K. C.

    1989-01-01

    Viewgraphs on experiment and simulation for control structure interaction (CSI) are presented. Topics covered include: control structure interaction; typical control/structure interaction system; CSI problem classification; actuator/sensor models; modeling uncertainty; noise models; real-time computations; and discrete versus continuous.

  14. A Computer Simulated Experiment in Complex Order Kinetics

    ERIC Educational Resources Information Center

    Merrill, J. C.; And Others

    1975-01-01

    Describes a computer simulation experiment in which physical chemistry students can determine all of the kinetic parameters of a reaction, such as order of the reaction with respect to each reagent, forward and reverse rate constants for the overall reaction, and forward and reverse activation energies. (MLH)

  15. Simulations of ultrafast x-ray laser experiments

    NASA Astrophysics Data System (ADS)

    Fortmann-Grote, C.; Andreev, A. A.; Appel, K.; Branco, J.; Briggs, R.; Bussmann, M.; Buzmakov, A.; Garten, M.; Grund, A.; Huebl, A.; Jurek, Z.; Loh, N. D.; Nakatsutsumi, M.; Samoylova, L.; Santra, R.; Schneidmiller, E. A.; Sharma, A.; Steiniger, K.; Yakubov, S.; Yoon, C. H.; Yurkov, M. V.; Zastrau, U.; Ziaja-Motyka, B.; Mancuso, A. P.

    2017-06-01

    Simulations of experiments at modern light sources, such as optical laser laboratories, synchrotrons, and free electron lasers, become increasingly important for the successful preparation, execution, and analysis of these experiments investigating ever more complex physical systems, e.g. biomolecules, complex materials, and ultra-short lived states of matter at extreme conditions. We have implemented a platform for complete start-to-end simulations of various types of photon science experiments, tracking the radiation from the source through the beam transport optics to the sample or target under investigation, its interaction with and scattering from the sample, and registration in a photon detector. This tool allows researchers and facility operators to simulate their experiments and instruments under real life conditions, identify promising and unattainable regions of the parameter space and ultimately make better use of valuable beamtime. In this paper, we present an overview about status and future development of the simulation platform and discuss three applications: 1.) Single-particle imaging of biomolecules using x-ray free electron lasers and optimization of x-ray pulse properties, 2.) x-ray scattering diagnostics of hot dense plasmas in high power laser-matter interaction and identification of plasma instabilities, and 3.) x-ray absorption spectroscopy in warm dense matter created by high energy laser-matter interaction and pulse shape optimization for low-isentrope dynamic compression.

  16. Meta-Analysis of Multiple Simulation-Based Experiments

    DTIC Science & Technology

    2013-06-01

    and Developing Hypotheses 6 Waterfall approach 1: Establishing the objectives of the meta - analysis and identifying the specific hypotheses that...Operational Environments” Paper ID: 48 Meta - Analysis of Multiple Simulation-Based Experiments Topics: Topic 5: Experimentation, Metrics, and...circumstances. Thus, effectively utilizing a variety of models in a prospective meta - analysis (a set of common hypotheses and controllable variables

  17. Optimising electron microscopy experiment through electron optics simulation.

    PubMed

    Kubo, Y; Gatel, C; Snoeck, E; Houdellier, F

    2017-04-01

    We developed a new type of electron trajectories simulation inside a complete model of a modern transmission electron microscope (TEM). Our model incorporates the precise and real design of each element constituting a TEM, i.e. the field emission (FE) cathode, the extraction optic and acceleration stages of a 300kV cold field emission gun, the illumination lenses, the objective lens, the intermediate and projection lenses. Full trajectories can be computed using magnetically saturated or non-saturated round lenses, magnetic deflectors and even non-cylindrical symmetry elements like electrostatic biprism. This multi-scale model gathers nanometer size components (FE tip) with parts of meter length (illumination and projection systems). We demonstrate that non-trivial TEM experiments requiring specific and complex optical configurations can be simulated and optimized prior to any experiment using such model. We show that all the currents set in all optical elements of the simulated column can be implemented in the real column (I2TEM in CEMES) and used as starting alignment for the requested experiment. We argue that the combination of such complete electron trajectory simulations in the whole TEM column with automatic optimization of the microscope parameters for optimal experimental data (images, diffraction, spectra) allows drastically simplifying the implementation of complex experiments in TEM and will facilitate the development of advanced use of the electron microscope in the near future. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. A Computer Simulated Experiment in Complex Order Kinetics

    ERIC Educational Resources Information Center

    Merrill, J. C.; And Others

    1975-01-01

    Describes a computer simulation experiment in which physical chemistry students can determine all of the kinetic parameters of a reaction, such as order of the reaction with respect to each reagent, forward and reverse rate constants for the overall reaction, and forward and reverse activation energies. (MLH)

  19. Experience with the Simulated Patient-Physician Encounter

    ERIC Educational Resources Information Center

    Friedman, Richard B.; And Others

    1978-01-01

    Computer-based simulations of the patient-physician encounter have been used at the University of Wisconsin Medical School for five years. They have been used to permit students to gain clinical experience, as part of a series of structured teaching conferences, and in a medical testing program. Student and faculty response is favorable.…

  20. Anticipating the Experience of Higher Education through Computer Simulation.

    ERIC Educational Resources Information Center

    Entwistle, Noel; And Others

    The development of a principled microcomputer-based adventure game that simulates the experience of higher education for prospective students in British schools is discussed. Playing the game is intended to provide prospective students a "realistic role preview." Consideration is given to an earlier board game and research on student…

  1. Students' experiences of learning manual clinical skills through simulation.

    PubMed

    Johannesson, Eva; Silén, Charlotte; Kvist, Joanna; Hult, Håkan

    2013-03-01

    Learning manual skills is a fundamental part of health care education, and motor, sensory and cognitive learning processes are essential aspects of professional development. Simulator training has been shown to enhance factors that facilitate motor and cognitive learning. The present study aimed to investigate the students' experiences and thoughts about their learning through simulation skills training. The study was designed for an educational setting at a clinical skills centre. Ten third-year undergraduate nursing students performed urethral catheterisation, using the virtual reality simulator UrecathVision™, which has haptic properties. The students practised in pairs. Each session was videotaped and the video was used to stimulate recall in subsequent interviews. The interviews were analysed using qualitative content analysis. The analysis from interviews resulted in three themes: what the students learn, how the students learn, and the simulator's contribution to the students' learning. Students learned manual skills, how to perform the procedure, and professional behaviour. They learned by preparing, watching, practising and reflecting. The simulator contributed by providing opportunities for students to prepare for the skills training, to see anatomical structures, to feel resistance, and to become aware of their own performance ability. The findings show that the students related the task to previous experiences, used sensory information, tested themselves and practised techniques in a hands-on fashion, and reflected in and on action. The simulator was seen as a facilitator to learning the manual skills. The study design, with students working in pairs combined with video recording, was found to enhance opportunities for reflection.

  2. Lattice Boltzmann modeling of directional wetting: Comparing simulations to experiments

    NASA Astrophysics Data System (ADS)

    Jansen, H. Patrick; Sotthewes, Kai; van Swigchem, Jeroen; Zandvliet, Harold J. W.; Kooij, E. Stefan

    2013-07-01

    Lattice Boltzmann Modeling (LBM) simulations were performed on the dynamic behavior of liquid droplets on chemically striped patterned surfaces, ultimately with the aim to develop a predictive tool enabling reliable design of future experiments. The simulations accurately mimic experimental results, which have shown that water droplets on such surfaces adopt an elongated shape due to anisotropic preferential spreading. Details of the contact line motion such as advancing of the contact line in the direction perpendicular to the stripes exhibit pronounced similarities in experiments and simulations. The opposite of spreading, i.e., evaporation of water droplets, leads to a characteristic receding motion first in the direction parallel to the stripes, while the contact line remains pinned perpendicular to the stripes. Only when the aspect ratio is close to unity, the contact line also starts to recede in the perpendicular direction. Very similar behavior was observed in the LBM simulations. Finally, droplet movement can be induced by a gradient in surface wettability. LBM simulations show good semiquantitative agreement with experimental results of decanol droplets on a well-defined striped gradient, which move from high- to low-contact angle surfaces. Similarities and differences for all systems are described and discussed in terms of the predictive capabilities of LBM simulations to model direction wetting.

  3. Lattice Boltzmann modeling of directional wetting: comparing simulations to experiments.

    PubMed

    Jansen, H Patrick; Sotthewes, Kai; van Swigchem, Jeroen; Zandvliet, Harold J W; Kooij, E Stefan

    2013-07-01

    Lattice Boltzmann Modeling (LBM) simulations were performed on the dynamic behavior of liquid droplets on chemically striped patterned surfaces, ultimately with the aim to develop a predictive tool enabling reliable design of future experiments. The simulations accurately mimic experimental results, which have shown that water droplets on such surfaces adopt an elongated shape due to anisotropic preferential spreading. Details of the contact line motion such as advancing of the contact line in the direction perpendicular to the stripes exhibit pronounced similarities in experiments and simulations. The opposite of spreading, i.e., evaporation of water droplets, leads to a characteristic receding motion first in the direction parallel to the stripes, while the contact line remains pinned perpendicular to the stripes. Only when the aspect ratio is close to unity, the contact line also starts to recede in the perpendicular direction. Very similar behavior was observed in the LBM simulations. Finally, droplet movement can be induced by a gradient in surface wettability. LBM simulations show good semiquantitative agreement with experimental results of decanol droplets on a well-defined striped gradient, which move from high- to low-contact angle surfaces. Similarities and differences for all systems are described and discussed in terms of the predictive capabilities of LBM simulations to model direction wetting.

  4. Quantum chemistry simulation on quantum computers: theories and experiments.

    PubMed

    Lu, Dawei; Xu, Boruo; Xu, Nanyang; Li, Zhaokai; Chen, Hongwei; Peng, Xinhua; Xu, Ruixue; Du, Jiangfeng

    2012-07-14

    It has been claimed that quantum computers can mimic quantum systems efficiently in the polynomial scale. Traditionally, those simulations are carried out numerically on classical computers, which are inevitably confronted with the exponential growth of required resources, with the increasing size of quantum systems. Quantum computers avoid this problem, and thus provide a possible solution for large quantum systems. In this paper, we first discuss the ideas of quantum simulation, the background of quantum simulators, their categories, and the development in both theories and experiments. We then present a brief introduction to quantum chemistry evaluated via classical computers followed by typical procedures of quantum simulation towards quantum chemistry. Reviewed are not only theoretical proposals but also proof-of-principle experimental implementations, via a small quantum computer, which include the evaluation of the static molecular eigenenergy and the simulation of chemical reaction dynamics. Although the experimental development is still behind the theory, we give prospects and suggestions for future experiments. We anticipate that in the near future quantum simulation will become a powerful tool for quantum chemistry over classical computations.

  5. Universality between Experiment and Simulation of a Diblock Copolymer Melt

    NASA Astrophysics Data System (ADS)

    Beardsley, Thomas M.; Matsen, Mark W.

    2016-11-01

    The equivalent behavior among analogous block copolymer systems involving chemically distinct molecules or mathematically different models has long hinted at an underlying universality, but only recently has it been rigorously demonstrated by matching results from different simulations. The profound implication of universality is that simple coarse-grained models can be calibrated so as to provide quantitatively accurate predictions to experiment. Here, we provide the first compelling demonstration of this by simulating a polyisoprene-polylactide diblock copolymer melt using a previously calibrated lattice model. The simulation successfully predicts the peak in the disordered-state structure function, the position of the order-disorder transition, and the latent heat of the transition in excellent quantitative agreement with experiment. This could mark a new era of precision in the field of block copolymer research.

  6. Universality between Experiment and Simulation of a Diblock Copolymer Melt.

    PubMed

    Beardsley, Thomas M; Matsen, Mark W

    2016-11-18

    The equivalent behavior among analogous block copolymer systems involving chemically distinct molecules or mathematically different models has long hinted at an underlying universality, but only recently has it been rigorously demonstrated by matching results from different simulations. The profound implication of universality is that simple coarse-grained models can be calibrated so as to provide quantitatively accurate predictions to experiment. Here, we provide the first compelling demonstration of this by simulating a polyisoprene-polylactide diblock copolymer melt using a previously calibrated lattice model. The simulation successfully predicts the peak in the disordered-state structure function, the position of the order-disorder transition, and the latent heat of the transition in excellent quantitative agreement with experiment. This could mark a new era of precision in the field of block copolymer research.

  7. Characteristics of Effective Clinical Teachers in Simulated Clinical Experiences Compared to Traditional Clinical Experiences

    ERIC Educational Resources Information Center

    Sieh-Bliss, Selina

    2014-01-01

    While there is evidence in the literature measuring effective clinical teacher characteristics in traditional experiences, little is known of effective characteristics expected from clinical teachers during simulated clinical experiences. This study examined which clinical teaching behaviors and characteristics are perceived by nursing students'…

  8. Characteristics of Effective Clinical Teachers in Simulated Clinical Experiences Compared to Traditional Clinical Experiences

    ERIC Educational Resources Information Center

    Sieh-Bliss, Selina

    2014-01-01

    While there is evidence in the literature measuring effective clinical teacher characteristics in traditional experiences, little is known of effective characteristics expected from clinical teachers during simulated clinical experiences. This study examined which clinical teaching behaviors and characteristics are perceived by nursing students'…

  9. Apollo experience report: Guidance and control systems. Engineering simulation program

    NASA Technical Reports Server (NTRS)

    Gilbert, D. W.

    1973-01-01

    The Apollo Program experience from early 1962 to July 1969 with respect to the engineering-simulation support and the problems encountered is summarized in this report. Engineering simulation in support of the Apollo guidance and control system is discussed in terms of design analysis and verification, certification of hardware in closed-loop operation, verification of hardware/software compatibility, and verification of both software and procedures for each mission. The magnitude, time, and cost of the engineering simulations are described with respect to hardware availability, NASA and contractor facilities (for verification of the command module, the lunar module, and the primary guidance, navigation, and control system), and scheduling and planning considerations. Recommendations are made regarding implementation of similar, large-scale simulations for future programs.

  10. Nursing students' self-assessment of their simulation experiences.

    PubMed

    Cato, Mary L; Lasater, Kathie; Peeples, Alycia Isabella

    2009-01-01

    This article describes a self-evaluation and feedback strategy used by nursing students and simulation faculty in a junior-level adult acute care course. Simulations are developed and implemented with the intention of furthering students' clinical judgment skills. A clinical judgment rubric, based on the Tanner Model of Clinical Judgment, is used as a self-assessment tool. The rubric describes the development of clinical judgment over four levels and is scored by students as they reflect on their practice. In addition to using the rubric's descriptors to rate themselves (Beginning, Developing, Accomplished, and Exemplary), the students apply an evidence-based process, citing simulation examples of their clinical thinking as support for their ratings. Simulation faculty respond to the postings, affirming students' observations or helping them experience a different perspective, and offer help to move toward the next stage of clinical judgment development. The postings offer clinical faculty insight into clinical judgment processes observed in the practicum settings.

  11. Three-dimensional simulations of Nova capsule implosion experiments

    SciTech Connect

    Marinak, M.M.; Tipton, R.E.; Landen, O.L.

    1995-11-01

    Capsule implosion experiments carried out on the Nova laser are simulated with the three-dimensional HYDRA radiation hydrodynamics code. Simulations of ordered near single mode perturbations indicate that structures which evolve into round spikes can penetrate farthest into the hot spot. Bubble-shaped perturbations can burn through the capsule shell fastest, however, causing even more damage. Simulations of a capsule with multimode perturbations shows spike amplitudes evolving in good agreement with a saturation model during the deceleration phase. The presence of sizable low mode asymmetry, caused either by drive asymmetry or perturbations in the capsule shell, can dramatically affect the manner in which spikes approach the center of the hot spot. Three-dimensional coupling between the low mode shell perturbations intrinsic to Nova capsules and the drive asymmetry brings the simulated yields into closer agreement with the experimental values.

  12. Simulation of Physical Experiments in Immersive Virtual Environments

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Wasfy, Tamer M.

    2001-01-01

    An object-oriented event-driven immersive Virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and various applications. The VLs interface with output devices, including immersive stereoscopic screed(s) and stereo speakers; and a variety of input devices, including body tracking (head and hands), haptic gloves, wand, joystick, mouse, microphone, and keyboard. The VL incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. Each object encapsulates a set of properties, methods, and events that define its behavior, appearance, and functions. A container object allows grouping of several objects. Applications of the VLs include viewing the results of the physical experiment, viewing a computer simulation of the physical experiment, simulation of the experiments procedure, computational steering, and remote control of the physical experiment. In addition, the VL can be used as a risk-free (safe) environment for training. The implementation of virtual structures testing machines, virtual wind tunnels, and a virtual acoustic testing facility is described.

  13. Comparing ballistic wounds with experiments on body simulator.

    PubMed

    Bresson, F; Franck, O

    2010-05-20

    This paper demonstrates how ballistic experiments on body simulator can bring a key information in the forensic science field. In the investigated case, a hunter was shot by accident in the back. Two hunters were suspected of having inadvertently shot towards the victim. The deadly bullet left the body and cannot be found on the scene neither in the body. The only way to discriminate the two options was to perform ballistic tests in body simulators. Even though the knowledge about body simulators is not enough advanced yet to expect accurate quantitative results, it was supposed to fully discriminate the two investigated cases as its respective impact energy are highly different (respectively 1200J and 2400J). For each investigated possibility, bullet's expansion state and body wounds were simulated. Bullet impact characteristics were determined by measuring the muzzle velocity, compute the impact velocity in the considered range (the position of each hunter is accurately known). Reloading cartridges allowed to reproduce accuretaly the corresponding velocity. The body was simulated by 3 different means in order to explore the accuracy of the simulation process. We demonstrated that the reported case is situated in a velocity/energy range in which body simulators do not need to be particularly accurate to reproduce the bullet expansion/non-expansion state. It furthermore demonstrated that only one case is compatible with the ballistic wounds of the victim. In the other case, the bullet's expansion would lead to a completely different wound shape.

  14. Complete Monte Carlo Simulation of Neutron Scattering Experiments

    NASA Astrophysics Data System (ADS)

    Drosg, M.

    2011-12-01

    In the far past, it was not possible to accurately correct for the finite geometry and the finite sample size of a neutron scattering set-up. The limited calculation power of the ancient computers as well as the lack of powerful Monte Carlo codes and the limitation in the data base available then prevented a complete simulation of the actual experiment. Using e.g. the Monte Carlo neutron transport code MCNPX [1], neutron scattering experiments can be simulated almost completely with a high degree of precision using a modern PC, which has a computing power that is ten thousand times that of a super computer of the early 1970s. Thus, (better) corrections can also be obtained easily for previous published data provided that these experiments are sufficiently well documented. Better knowledge of reference data (e.g. atomic mass, relativistic correction, and monitor cross sections) further contributes to data improvement. Elastic neutron scattering experiments from liquid samples of the helium isotopes performed around 1970 at LANL happen to be very well documented. Considering that the cryogenic targets are expensive and complicated, it is certainly worthwhile to improve these data by correcting them using this comparatively straightforward method. As two thirds of all differential scattering cross section data of 3He(n,n)3He are connected to the LANL data, it became necessary to correct the dependent data measured in Karlsruhe, Germany, as well. A thorough simulation of both the LANL experiments and the Karlsruhe experiment is presented, starting from the neutron production, followed by the interaction in the air, the interaction with the cryostat structure, and finally the scattering medium itself. In addition, scattering from the hydrogen reference sample was simulated. For the LANL data, the multiple scattering corrections are smaller by a factor of five at least, making this work relevant. Even more important are the corrections to the Karlsruhe data due to the

  15. Premission and postmission simulation studies of the foot-controlled maneuvering unit for Skylab experiment T-020. [astronaut maneuvering equipment - space environment simulation

    NASA Technical Reports Server (NTRS)

    Hewes, D. E.; Glover, K. E.

    1975-01-01

    A Skylab experiment was conducted to study the maneuvering capabilities of astronauts using a relatively simple self-locomotive device, referred to as the foot-controlled maneuvering unit, and to evaluate the effectiveness of ground-based facilities simulating the operation of this device in weightless conditions of space. Some of the special considerations given in the definition and development of the experiment as related to the two ground-based simulators are reviewed. These simulators were used to train the test subjects and to obtain baseline data which could be used for comparison with the in-flight tests that were performed inside the Skylab orbital workshop. The results of both premission and postmission tests are discussed, and subjective comparisons of the in-flight and ground-based test conditions are presented.

  16. Post Shot Simulations of NIF Convergent Ablator Experiments

    NASA Astrophysics Data System (ADS)

    Olson, R. E.; Meezan, N. B.; Hicks, D. G.; Landen, O. L.; Dewald, E. L.; Jones, O. S.; Langer, S. H.; Callahan, D. A.; Petrasso, R. D.; Zylstra, A. B.

    2012-10-01

    Post shot simulations of NIF convergent ablator experiments will be described. The experiments use a streaked radiograph of a backlit capsule implosion to measure the trajectory, velocity, remaining mass, and ablator rhoR and are an important component of the U. S. National Ignition Campaign. The integrated (capsule-in-hohlraum) post shot simulations use measured target parameters, measured laser input powers, measured time-resolved backscatter, and calculated cross-beam power transfer. The integrated calculations are post-processed to provide simulations of the key diagnostics, including: 1) Dante measurements of the hohlraum x-ray flux and spectrum; 2) streaked radiographs of the imploding ablator shell; 3) wedge range filter measurements of D-He3 proton output spectra; and 4) GXD images of the imploded core. The simulated diagnostics are compared to the experimental measurements to provide an assessment of the accuracy of the design code, to enhance understanding of the experiments, and to assist in choosing parameters for subsequent steps in the path towards optimal ignition capsule tuning.

  17. Simulation of UCN transport in the UCN τ Experiment

    NASA Astrophysics Data System (ADS)

    Adamek, Evan; Liu, Chen-Yu; Salvat, Daniel; Callahan, Nathan; UCNτ Collaboration

    2013-10-01

    The UCN τ experiment aims to measure the neutron β-decay lifetime to 1 s total uncertainty and beyond by trapping ultracold neutrons (UCN) in a magneto-gravitational trap, in which UCN undergo no material interactions with the walls of the trap. To investigate UCN transport in the experiment, we have built Monte-Carlo simulations of the full-scale experiment using GEANT4. We have modeled the delivery of UCN to the trap with a highly accurate transport geometry. The model is bench-marked against the experimental data collected in the early 2013 run. The simulation is used to compare proposed geometry upgrades to enhance the efficiency of UCN delivery (planned for the late 2013 run). In addition, work is underway to expand the scope of simulation to include β and γ detection, with the goal of modeling our in-situ UCN detector using the technique of neutron activation on a large-surface Vanadium foil. Here we present the results of this simulation effort. The work is supported by the NSF grant PHY-1068712.

  18. Processing biobased polymers using plasticizers: Numerical simulations versus experiments

    NASA Astrophysics Data System (ADS)

    Desplentere, Frederik; Cardon, Ludwig; Six, Wim; Erkoç, Mustafa

    2016-03-01

    In polymer processing, the use of biobased products shows lots of possibilities. Considering biobased materials, biodegradability is in most cases the most important issue. Next to this, bio based materials aimed at durable applications, are gaining interest. Within this research, the influence of plasticizers on the processing of the bio based material is investigated. This work is done for an extrusion grade of PLA, Natureworks PLA 2003D. Extrusion through a slit die equipped with pressure sensors is used to compare the experimental pressure values to numerical simulation results. Additional experimental data (temperature and pressure data along the extrusion screw and die are recorded) is generated on a dr. Collin Lab extruder producing a 25mm diameter tube. All these experimental data is used to indicate the appropriate functioning of the numerical simulation tool Virtual Extrusion Laboratory 6.7 for the simulation of both the industrial available extrusion grade PLA and the compound in which 15% of plasticizer is added. Adding the applied plasticizer, resulted in a 40% lower pressure drop over the extrusion die. The combination of different experiments allowed to fit the numerical simulation results closely to the experimental values. Based on this experience, it is shown that numerical simulations also can be used for modified bio based materials if appropriate material and process data are taken into account.

  19. CET exSim: mineral exploration experience via simulation

    NASA Astrophysics Data System (ADS)

    Wong, Jason C. 13Holden, Eun-Jung 1Kovesi, Peter 1McCuaig, T. Campbell 1Hronsky, Jon

    2013-08-01

    Undercover mineral exploration is a challenging task as it requires understanding of subsurface geology by relying heavily on remotely sensed (i.e. geophysical) data. Cost-effective exploration is essential in order to increase the chance of success using finite budgets. This requires effective decision-making in both the process of selecting the optimum data collection methods and in the process of achieving accuracy during subsequent interpretation. Traditionally, developing the skills, behaviour and practices of exploration decision-making requires many years of experience through working on exploration projects under various geological settings, commodities and levels of available resources. This implies long periods of sub-optimal exploration decision-making, before the necessary experience has been successfully obtained. To address this critical industry issue, our ongoing research focuses on the development of the unique and novel e-learning environment, exSim, which simulates exploration scenarios where users can test their strategies and learn the consequences of their choices. This simulator provides an engaging platform for self-learning and experimentation in exploration decision strategies, providing a means to build experience more effectively. The exSim environment also provides a unique platform on which numerous scenarios and situations (e.g. deposit styles) can be simulated, potentially allowing the user to become virtually familiarised with a broader scope of exploration practices. Harnessing the power of computer simulation, visualisation and an intuitive graphical user interface, the simulator provides a way to assess the user's exploration decisions and subsequent interpretations. In this paper, we present the prototype functionalities in exSim including: simulation of geophysical surveys, follow-up drill testing and interpretation assistive tools.

  20. Learner performance and attitudes in traditional versus simulated lab experiences

    NASA Astrophysics Data System (ADS)

    Pyatt, Kevin A.

    The expository laboratory, a type of physical laboratory that has prescribed outcomes, was initially designed to address learning environments and laboratory environments of the 20th century. Evidence suggests that it has lost its instructional value. Emerging technologies such as simulations have a multitude of instructional benefits which can serve as robust replacements for the expository lab. There is evidence that the expository lab is being redefined and may need to be redesigned for the online world. These changes have not been realized, however, due to the current accreditation process which does not recognize the simulated lab as a legitimate alternative to expository labs. This study investigated whether simulated laboratories can achieve the goals of contemporary lab instruction as successfully as the expository lab paradigm. This study addressed the differences and similarities in student attitudes toward using a simulated lab and an expository lab. The methodology used in this study was experimental and quantitative in nature. Two experiments were carried out, each of which comprised the completion of a lab activity by participants who were assigned to a control group (expository lab) or an experimental group (simulated lab). This study found that there were significant differences between the assessment means of the simulated lab groups and the expository lab groups. The assessment means for the simulated lab groups were significantly higher than the assessment means of the expository lab groups. In terms of learner attitude, it was found that simulated labs were perceived to be more open-ended, easier to use, and easier to generate usable data, than expository labs. Moreover, students preferred using simulated labs over expository labs, and the time to complete simulated lab activities was significantly less than the time to complete expository lab activities. This study showed that the simulated lab can serve as a legitimate alternative to the

  1. Comparison of Electron Cloud Simulation and Experiments in the High-Current Experiment

    SciTech Connect

    Cohen, R; Friedman, A; Covo, M K; Lund, S; Molvik, A; Bieniosek, F; Seidl, P; Vay, J; Verboncoeur, J; Stoltz, P; Veitzer, S

    2004-10-07

    A set of experiments has been performed on the High-Current Experiment (HCX) facility at LBNL, in which the ion beam is allowed to collide with an end plate and thereby induce a copious supply of desorbed electrons. Through the use of combinations of biased and grounded electrodes positioned in between and downstream of the quadrupole magnets, the flow of electrons upstream into the magnets can be turned on or off. Properties of the resultant ion beam are measured under each condition. The experiment is modeled via a full three-dimensional, two species (electron and ion) particle simulation, as well as via reduced simulations (ions with appropriately chosen model electron cloud distributions, and a high-resolution simulation of the region adjacent to the end plate). The three-dimensional simulations are the first of their kind and the first to make use of a timestep-acceleration scheme that allows the electrons to be advanced with a timestep that is not small compared to the highest electron cyclotron period. The simulations reproduce qualitative aspects of the experiments, illustrate some unanticipated physical effects, and serve as an important demonstration of a developing simulation capability.

  2. Comparison of electron cloud simulation and experiments in the high-current experiment

    SciTech Connect

    Cohen, R.H.; Friedman, A.; Covo, M. Kireeff; Lund, S.M.; Molvik, A.W.; Bieniosek, F.M.; Seidl, P.A.; Vay, J.-L.; Verboncoeur, J.; Stoltz, P.; Veitzer, S.

    2004-08-27

    A set of experiments has been performed on the High-Current Experiment (HCX) facility at LBNL, in which the ion beam is allowed to collide with an end plate and thereby induce a copious supply of desorbed electrons. Through the use of combinations of biased and grounded electrodes positioned in between and downstream of the quadrupole magnets, the flow of electrons upstream into the magnets can be turned on or off. Properties of the resultant ion beam are measured under each condition. The experiment is modeled via a full three-dimensional, two species (electron and ion) particle simulation, as well as via reduced simulations (ions with appropriately chosen model electron cloud distributions, and a high-resolution simulation of the region adjacent to the end plate). The three-dimensional simulations are the first of their kind and the first to make use of a timestep-acceleration scheme that allows the electrons to be advanced with a timestep that is not small compared to the highest electron cyclotron period. The simulations reproduce qualitative aspects of the experiments, illustrate some unanticipated physical effects, and serve as an important demonstration of a developing simulation capability.

  3. Engineering and simulation of life science Spacelab experiments

    NASA Technical Reports Server (NTRS)

    Bush, B.; Rummel, J.; Johnston, R. S.

    1977-01-01

    Approaches to the planning and realization of Spacelab life sciences experiments, which may involve as many as 16 Space Shuttle missions and 100 tests, are discussed. In particular, a Spacelab simulation program, designed to evaluate problems associated with the use of live animal specimens, the constraints imposed by zero gravity on equipment operation, training of investigators and data management, is described. The simulated facility approximates the hardware and support systems of a current European Space Agency Spacelab model. Preparations necessary for the experimental program, such as crew activity plans, payload documentation and inflight experimental procedures are developed; health problems of the crew, including human/animal microbial contamination, are also assessed.

  4. Virtual experiments: Combining realistic neutron scattering instrument and sample simulations

    NASA Astrophysics Data System (ADS)

    Farhi, E.; Hugouvieux, V.; Johnson, M. R.; Kob, W.

    2009-08-01

    A new sample component is presented for the Monte Carlo, ray-tracing program, McStas, which is widely used to simulate neutron scattering instruments. The new component allows the sample to be described by its material dynamic structure factor, which is separated into coherent and incoherent contributions. The effects of absorption and multiple scattering are treated and results from simulations and previous experiments are compared. The sample component can also be used to treat any scattering material which may be close to the sample and therefore contaminates the total, measured signal.

  5. Brain simulation of action may be grounded in physical experience.

    PubMed

    Olsson, C J; Nyberg, Lars

    2011-12-01

    An intriguing quality of our brain is that when actions are imagined, corresponding brain regions are recruited as when the actions are actually performed. It has been hypothesized that the similarity between real and simulated actions depends on the nature of motor representations. Here we tested this hypothesis by examining S.D., who never used her legs but is an elite wheel chair athlete. Controls recruited motor brain regions during imagery of stair walking and frontal regions during imagery of wheel chair slalom. S.D. showed the opposite pattern. Thus, brain simulation of actions may be grounded in specific physical experiences.

  6. Engineering and simulation of life science Spacelab experiments

    NASA Technical Reports Server (NTRS)

    Bush, B.; Rummel, J.; Johnston, R. S.

    1977-01-01

    Approaches to the planning and realization of Spacelab life sciences experiments, which may involve as many as 16 Space Shuttle missions and 100 tests, are discussed. In particular, a Spacelab simulation program, designed to evaluate problems associated with the use of live animal specimens, the constraints imposed by zero gravity on equipment operation, training of investigators and data management, is described. The simulated facility approximates the hardware and support systems of a current European Space Agency Spacelab model. Preparations necessary for the experimental program, such as crew activity plans, payload documentation and inflight experimental procedures are developed; health problems of the crew, including human/animal microbial contamination, are also assessed.

  7. A system for designing and simulating particle physics experiments

    NASA Astrophysics Data System (ADS)

    Żelazny, Roman; Strzałkowski, Piotr

    1987-01-01

    In view of the rapid development of experimental facilities and their costs, the systematic design and preparation of particle physics experiments have become crucial. A software system is proposed as an aid for the experimental designer, mainly for experimental geometry analysis and experimental simulation. The following model is adopted: the description of an experiment is formulated in a language (here called XL) and put by its processor in a data base. The language is based on the entity-relationship-attribute approach. The information contained in the data base can be reported and analysed by an analyser (called XA) and modifications can be made at any time. In particular, the Monte Carlo methods can be used in experiment simulation for both physical phenomena in experimental set-up and detection analysis. The general idea of the system is based on the design concept of ISDOS project information systems. The characteristics of the simulation module are similar to those of the CERN Geant system, but some extensions are proposed. The system could be treated as a component of a greater, integrated software environment for the design of particle physics experiments, their monitoring and data processing.

  8. Transit bus operator performance and attitudes toward a collision warning system: results of a simulator experiment.

    PubMed

    Reinach, Stephen J; Everson, Jeffrey H

    2005-09-01

    This article discusses the results of a simulator experiment to examine the efficacy of a collision warning system for transit bus operators. Bus operators from a major metropolitan transit agency were assigned to one of three conditions: a collision warning system with a visual-only driver-vehicle interface, a collision warning system with a visual and auditory driver-vehicle interface, or no collision warning system (baseline). Operators were exposed to a critical event at the end of the simulation, in which a vehicle suddenly stopped in front of the bus while the operator was distracted by an in-vehicle task. Upon completing the experiment, operators who used the collision warning system were asked about their experience using the system, as well as whether or not they would like such a system in real life. Experimental results revealed new information about transit bus operator performance, but indicated no statistically significant differences among the three conditions. Subjective data indicated that operators had a positive attitude toward collision warning system usage. Operators generally liked the collision warning system and felt that a system such as the one used in the experiment would help them in avoiding crashes in the real world. These findings suggest that a collision warning system for transit bus operators is feasible from the perspective of user acceptance. However, several technical areas still need to be resolved.

  9. Relating a Jet-Surface Interaction Experiment to a Commercial Supersonic Transport Aircraft Using Numerical Simulations

    NASA Technical Reports Server (NTRS)

    Dippold, Vance F. III; Friedlander, David

    2017-01-01

    Reynolds-Averaged Navier-Stokes (RANS) simulations were performed for a commercial supersonic transport aircraft concept and experimental hardware models designed to represent the installed propulsion system of the conceptual aircraft in an upcoming test campaign. The purpose of the experiment is to determine the effects of jet-surface interactions from supersonic aircraft on airport community noise. RANS simulations of the commercial supersonic transport aircraft concept were performed to relate the representative experimental hardware to the actual aircraft. RANS screening simulations were performed on the proposed test hardware to verify that it would be free from potential rig noise and to predict the aerodynamic forces on the model hardware to assist with structural design. The simulations showed a large region of separated flow formed in a junction region of one of the experimental configurations. This was dissimilar with simulations of the aircraft and could invalidate the noise measurements. This configuration was modified and a subsequent RANS simulation showed that the size of the flow separation was greatly reduced. The aerodynamic forces found on the experimental models were found to be relatively small when compared to the expected loads from the model’s own weight.Reynolds-Averaged Navier-Stokes (RANS) simulations were completed for two configurations of a three-stream inverted velocity profile (IVP) nozzle and a baseline single-stream round nozzle (mixed-flow equivalent conditions). For the Sideline and Cutback flow conditions, while the IVP nozzles did not reduce the peak turbulent kinetic energy on the lower side of the jet plume, the IVP nozzles did significantly reduce the size of the region of peak turbulent kinetic energy when compared to the jet plume of the baseline nozzle cases. The IVP nozzle at Sideline conditions did suffer a region of separated flow from the inner stream nozzle splitter that did produce an intense, but small, region of

  10. An Observing System Simulation Experiment Approach to Meteorological Network Assessment

    NASA Astrophysics Data System (ADS)

    Abbasnezhadi, K.; Rasmussen, P. F.; Stadnyk, T.; Boluwade, A.

    2016-12-01

    A proper knowledge of the spatiotemporal distribution of rainfall is important in order to conduct a mindful investigation of water movement and storage throughout a catchment. Currently, the most accurate precipitation information available for the remote Boreal ecozones of northern Manitoba is coming from the Canadian Precipitation Analysis (CaPA) data assimilation system. Throughout the Churchill River Basin (CRB), CaPA still does not have the proper skill due to the limited number of weather stations. A new approach to experimental network design was investigated based on the concept of Observing System Simulation Experiment (OSSE). The OSSE-based network assessment procedure which simulates the CaPA system provides a scientific and hydrologically significant tool to assess the sensitivity of CaPA precipitation analysis to observation network density throughout the CRB. To simulate CaPA system, synthetic background and station data were simulated, respectively, by adding spatially uncorrelated and correlated Gaussian noises to an assumingly true daily weather field synthesized by a gridded precipitation generator which simulates CaPA data. Given the true reference field on one hand, and a set of pseudo-CaPA analyses associated with different network realizations on the other hand, a WATFLOOD hydrological model was employed to compare the modeled runoff. The simulations showed that as network density increases, the accuracy of CaPA precipitation products improves up to a certain limit beyond which adding more stations to the network does not result in further accuracy.

  11. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    NASA Astrophysics Data System (ADS)

    Trantham, Matthew; Kuranz, Carolyn; Manuel, Mario; Keiter, Paul; Drake, R. P.

    2014-10-01

    Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster/talk will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, imploding bubbles, and interacting jet experiments. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via Grant DEFC52-08NA28616, by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0001840, and by the National Laser User Facility Program, Grant Number DE-NA0000850.

  12. Midwifery students' experiences of simulation- and skills training.

    PubMed

    Lendahls, Lena; Oscarsson, Marie G

    2017-03-01

    In Sweden, simulation- and skills training are implemented in midwifery education in order to prepare students for clinical practice. Research regarding the use of both low to high levels of fidelity in simulation in midwifery programme is limited. The aim of this study was to explore midwifery students' experiences of simulation- and skills training. Midwifery students (n=61), at advanced level, were interviewed in 13 group interviews from 2011 to 2105. A semi-structured interview guide was used, and data were analysed by content analysis. The results are presented in four main categories: develops hands on skills and communication, power of collaborative learning, highly valued learning environment and facilitates clinical practice. The majority of students felt that the simulation- and skills training were necessary to become familiar with hands on skills. Having repetitive practices in a safe and secure environment was viewed as important, and students highly valued that mistakes could be made without fear of comprising patient safety. Student's collaboration, reflections and critical thinking increased learning ability. Simulation- and skills training created links between theory and practice, and the lecturer had an important role in providing instructions and feedback. Students felt prepared and confident before their clinical practice, and simulation- and skills training increased safety for all involved, resulting in students being more confident, as patients in clinical practice became less exposed. Furthermore, mentors were satisfied with students' basic skills. Simulation- and skills training support the development of midwifery skills. It creates links between theory and practice, which facilitates students' learning ability. Training needs to include reflections and critical thinking in order to develop their learning. The lecturer has an important role in encouraging time for reflections and creating safe environment during the skills and simulation

  13. The hydrodynamics of astrophysical jets: scaled experiments and numerical simulations

    NASA Astrophysics Data System (ADS)

    Belan, M.; Massaglia, S.; Tordella, D.; Mirzaei, M.; de Ponte, S.

    2013-06-01

    Context. In this paper we study the propagation of hypersonic hydrodynamic jets (Mach number >5) in a laboratory vessel and make comparisons with numerical simulations of axially symmetric flows with the same initial and boundary conditions. The astrophysical context is that of the jets originating around young stellar objects (YSOs). Aims: In order to gain a deeper insight into the phenomenology of YSO jets, we performed a set of experiments and numerical simulations of hypersonic jets in the range of Mach numbers from 10 to 20 and for jet-to-ambient density ratios from 0.85 to 5.4, using different gas species and observing jet lengths of the order of 150 initial radii or more. Exploiting the scalability of the hydrodynamic equations, we intend to reproduce the YSO jet behaviour with respect to jet velocity and elapsed times. In addition, we can make comparisons between the simulated, the experimental, and the observed morphologies. Methods: In the experiments the gas pressure and temperature are increased by a fast, quasi-isentropic compression by means of a piston system operating on a time scale of tens of milliseconds, while the gas density is visualized and measured by means of an electron beam system. We used the PLUTO software for the numerical solution of mixed hyperbolic/parabolic conservation laws targeting high Mach number flows in astrophysical fluid dynamics. We considered axisymmetric initial conditions and carried out numerical simulations in cylindrical geometry. The code has a modular flexible structure whereby different numerical algorithms can be separately combined to solve systems of conservation laws using the finite volume or finite difference approach based on Godunov-type schemes. Results: The agreement between experiments and numerical simulations is fairly good in most of the comparisons. The resulting scaled flow velocities and elapsed times are close to the ones shown by observations. The morphologies of the density distributions agree

  14. Simulations of silicon vertex tracker for star experiment at RHIC

    SciTech Connect

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W.; Liko, D.; Cramer, J.; Prindle, D.; Trainor, T.; Braithwaite, W.

    1991-12-31

    The first computer simulations to optimize the Silicon Vertex Tracker (SVT) designed for the STAR experiment at RHIC are presented. The physics goals and the expected complexity of the events at RHIC dictate the design of a tracking system for the STAR experiment. The proposed tracking system will consist of a silicon vertex tracker (SVT) to locate the primary interaction and secondary decay vertices and to improve the momentum resolution, and a time projection chamber (TPC), positioned inside a solenoidal magnet, for continuous tracking.

  15. Observing System Simulation Experiments for Fun and Profit

    NASA Technical Reports Server (NTRS)

    Prive, Nikki C.

    2015-01-01

    Observing System Simulation Experiments can be powerful tools for evaluating and exploring both the behavior of data assimilation systems and the potential impacts of future observing systems. With great power comes great responsibility - given a pure modeling framework, how can we be sure our results are meaningful? The challenges and pitfalls of OSSE calibration and validation will be addressed, as well as issues of incestuousness, selection of appropriate metrics, and experiment design. The use of idealized observational networks to investigate theoretical ideas in a fully complex modeling framework will also be discussed

  16. On integrating large eddy simulation and laboratory turbulent flow experiments.

    PubMed

    Grinstein, Fernando F

    2009-07-28

    Critical issues involved in large eddy simulation (LES) experiments relate to the treatment of unresolved subgrid scale flow features and required initial and boundary condition supergrid scale modelling. The inherently intrusive nature of both LES and laboratory experiments is noted in this context. Flow characterization issues becomes very challenging ones in validation and computational laboratory studies, where potential sources of discrepancies between predictions and measurements need to be clearly evaluated and controlled. A special focus of the discussion is devoted to turbulent initial condition issues.

  17. Bringing history to life: simulating landmark experiments in psychology.

    PubMed

    Boynton, David M; Smith, Laurence D

    2006-05-01

    The course in history of psychology can be challenging for students, many of whom enter it with little background in history and faced with unfamiliar names and concepts. The sheer volume of material can encourage passive memorization unless efforts are made to increase student involvement. As part of a trend toward experiential history, historians of science have begun to supplement their lectures with demonstrations of classic physics experiments as a way to bring the history of science to life. Here, the authors report on computer simulations of five landmark experiments from early experimental psychology in the areas of reaction time, span of attention, and apparent motion. The simulations are designed not only to permit hands-on replication of historically important results but also to reproduce the experimental procedures closely enough that students can gain a feel for the nature of early research and the psychological processes being studied.

  18. Stochastic simulation of single-molecule pulling experiments.

    PubMed

    Gupta, V K

    2014-10-01

    Single-molecule pulling experiments are widely used for studying the structure, dynamics, and function of single biological molecules via applying mechanical forces on them in a controlled way. Pulling at a constant speed or at a constant force builds up a mechanical force on a molecule or molecular complex leading to a molecular transition such as the dissociation of a molecular complex, unfolding of a protein, or unwrapping of a higher-order structure. We perform Brownian dynamics and Monte Carlo simulations of single-molecule pulling experiments. Through our simulations we demonstrate that the molecular transition rate based on the Kramers theory in the high-barrier limit becomes unsuitable as the applied force approaches the critical force at which the barrier disappears. We also demonstrate that use of molecular transition rate based on mean first passage time (MFPT) approach would be more relevant in describing molecular transition especially as the applied force approaches the critical force.

  19. Neutron Generation Simulations of Collisionless Shock Experiments on NIF

    NASA Astrophysics Data System (ADS)

    Wilks, S. C.; Higginson, D. P.; Weber, S. V.; Ryutov, D. D.; Ross, J. S.; Park, H.-S.; Fiuza, F.

    2015-11-01

    A series of simulations that model recent collisionless shock experiments at the NIF will be presented. In these experiments, two opposing CD plasmas flow into each other, both plasmas arising from lasers hitting planar CD targets separated by 6, 8, and 10mm. Where the plasma flows overlap, a symmetric peak of neutron generation was observed about the mid-plane. When one of the CD foils was replaced by CH, neutron generation was still observed, but with an asymmetry about the mid-plane. The hybrid PIC code LSP is used to model this interaction. Neutron yields, temporal profiles and burn widths obtained from simulation compare favorably with experimental measurements from NTOF and PTOF diagnostics. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-675193.

  20. Simulation studies of plasma lens experiments at Daresbury laboratory

    NASA Astrophysics Data System (ADS)

    Hanahoe, K.; Mete, O.; Xia, G.; Angal-Kalinin, D.; Jones, J.; Smith, J.

    2016-03-01

    Experiments are planned to study plasma lensing using the VELA and CLARA Front End accelerators at Daresbury Laboratory. This paper presents results of 2-dimensional particle-in-cell simulations of the proposed experiments. The variation in focusing strength and emittance growth with beam and plasma parameters are studied in the overdense (plasma density much greater than bunch density) regime for the VELA beam. The effect of spherical and longitudinal aberrations on the beam emittance was estimated through numerical and theoretical studies. Simulation results show that a focusing strength equivalent to a magnetic field gradient of 10 T m-1 can be achieved using VELA, and a gradient of 247 T m-1 can be achieved using CLARA Front End.

  1. Short Rayleigh length free electron laser: Experiments and simulations

    SciTech Connect

    Crooker, P.P.; Colson, William; Blau, Joe; Burggraff, D.; Sans Aguilar, J.; Benson, Stephen; Neil, George; Michelle D. Shinn; Evtushenko, Pavel

    2008-09-01

    DOI: http://dx.doi.org/10.1103/PhysRevSTAB.11.090701
    We report experiments at Jefferson National Accelerator Facility (Jlab) and computer simulations performed at the Naval Postgraduate School (NPS) designed to probe the small Rayleigh length regime. We compare the gain, power, and sensitivity to mirror and electron beam misalignments as a function of decreasing Rayleigh length. The agreement is quite good, with experiments and simulations showing comparable trends as the Rayleigh length is decreased. In particular, we find that the gain and power do not decrease substantially at short Rayleigh length, contrary to a common Gaussian-mode filling factor argument. Within currently achievable alignment tolerances, the gain and power are still acceptable for FEL operation.

  2. Virtual Reality Simulation of the International Space Welding Experiment

    NASA Technical Reports Server (NTRS)

    Phillips, James A.

    1996-01-01

    Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.

  3. Cloud Simulation Warm Cloud Experiments: Droplet Growth and Aerosol Scavenging.

    DTIC Science & Technology

    1988-03-02

    cloud simulation facility capabilities and experiments (Hagen, Alcorn, Alofs, Anderson, Carstens, Hopkins, Salk , Schmitt, Trueblood, White) 4. Conference...Snowmass, CO, AMS, 145-148. Jonas , P.R., and B.J. Mason, 1982: Entrainment and the droplet spectrumin cumulus clouds. Quart. J. Roy. Meteor. Soc. 108...distribution near the base of cumulus clouds. Quart. J. Roy. Meteor. Soc. 108, 917-928. Mason, B.J., and P.R. Jonas , 1984: The evolution of droplet

  4. Numerical prediction experiments simulating the impact of mesoscale satellite data

    NASA Technical Reports Server (NTRS)

    Kreitzberg, C. W.

    1979-01-01

    Recent developments in mesometeorology are summarized to place this research in perspective. Recent advances in computer analysis and forecast system development that provide the basis for the simulation tests are discussed. The impact of NIMBUS-6 humidity data on analyses off the West Coast are shown and incorporation of geopotential gradient data is discussed. Experiments to demonstrate the feasibility of incorporating satellite-derived wind fields in mesoscale severe storm models are mentioned briefly.

  5. Information-Based Evacuation Experiment and its Cellular Automaton Simulation

    NASA Astrophysics Data System (ADS)

    Yang, Lizhong; Liu, Shaobo; Li, Jian; Zhu, Kongjin; Fang, Tingyong

    The evacuation process under emergency is studied by means of experiments and simulations, focusing on the influence of the environment information. A revised cellular automaton model in which environment information is considered as "static information" (building structure, spatial distance, etc.) and "dynamic information" (sounds of fire alarm, etc.) is introduced. Two scenarios, including evacuation with and without visibility in a classroom, are studied to investigate the different influence of the two kinds of information on human behavior. The experimental and simulation results demonstrate that: (1) to intensify the spatial distance information can reduce the evacuation time; (2) the spatial distance is not the only decisive factor especially in evacuation without visibility because the sound information, which is ignorable in evacuation with visibility, is playing a more important role under this condition; (3) the intensity of static information can reflect evacuees' familiarity of the environment; (4) the model can reproduce the experiments well, and the simulation method is useful for further study of the crowd movement simulation.

  6. Fatigue Damage of Collagenous Tissues: Experiment, Modeling and Simulation Studies

    PubMed Central

    Martin, Caitlin; Sun, Wei

    2017-01-01

    Mechanical fatigue damage is a critical issue for soft tissues and tissue-derived materials, particularly for musculoskeletal and cardiovascular applications; yet, our understanding of the fatigue damage process is incomplete. Soft tissue fatigue experiments are often difficult and time-consuming to perform, which has hindered progress in this area. However, the recent development of soft-tissue fatigue-damage constitutive models has enabled simulation-based fatigue analyses of tissues under various conditions. Computational simulations facilitate highly controlled and quantitative analyses to study the distinct effects of various loading conditions and design features on tissue durability; thus, they are advantageous over complex fatigue experiments. Although significant work to calibrate the constitutive models from fatigue experiments and to validate predictability remains, further development in these areas will add to our knowledge of soft-tissue fatigue damage and will facilitate the design of durable treatments and devices. In this review, the experimental, modeling, and simulation efforts to study collagenous tissue fatigue damage are summarized and critically assessed. PMID:25955007

  7. Hypervelocity impacts into porous graphite: experiments and simulations

    NASA Astrophysics Data System (ADS)

    Hébert, D.; Seisson, G.; Rullier, J.-L.; Bertron, I.; Hallo, L.; Chevalier, J.-M.; Thessieux, C.; Guillet, F.; Boustie, M.; Berthe, L.

    2017-01-01

    We present experiments and numerical simulations of hypervelocity impacts of 0.5 mm steel spheres into graphite, for velocities ranging between 1100 and 4500 m s-1. Experiments have evidenced that, after a particular striking velocity, depth of penetration no longer increases but decreases. Moreover, the projectile is observed to be trapped below the crater surface. Using numerical simulations, we show how this experimental result can be related to both materials, yield strength. A Johnson-Cook model is developed for the steel projectile, based on the literature data. A simple model is proposed for the graphite yield strength, including a piecewise pressure dependence of the Drucker-Prager form, which coefficients have been chosen to reproduce the projectile penetration depth. Comparisons between experiments and simulations are presented and discussed. The damage properties of both materials are also considered, by using a threshold on the first principal stress as a tensile failure criterion. An additional compressive failure model is also used for graphite when the equivalent strain reaches a maximum value. We show that the experimental crater diameter is directly related to the graphite spall strength. Uncertainties on the target yield stress and failure strength are estimated. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  8. Hypervelocity impacts into porous graphite: experiments and simulations.

    PubMed

    Hébert, D; Seisson, G; Rullier, J-L; Bertron, I; Hallo, L; Chevalier, J-M; Thessieux, C; Guillet, F; Boustie, M; Berthe, L

    2017-01-28

    We present experiments and numerical simulations of hypervelocity impacts of 0.5 mm steel spheres into graphite, for velocities ranging between 1100 and 4500 m s(-1) Experiments have evidenced that, after a particular striking velocity, depth of penetration no longer increases but decreases. Moreover, the projectile is observed to be trapped below the crater surface. Using numerical simulations, we show how this experimental result can be related to both materials, yield strength. A Johnson-Cook model is developed for the steel projectile, based on the literature data. A simple model is proposed for the graphite yield strength, including a piecewise pressure dependence of the Drucker-Prager form, which coefficients have been chosen to reproduce the projectile penetration depth. Comparisons between experiments and simulations are presented and discussed. The damage properties of both materials are also considered, by using a threshold on the first principal stress as a tensile failure criterion. An additional compressive failure model is also used for graphite when the equivalent strain reaches a maximum value. We show that the experimental crater diameter is directly related to the graphite spall strength. Uncertainties on the target yield stress and failure strength are estimated.This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'. © 2016 The Author(s).

  9. Hydrodynamic simulations of gaseous Argon shock compression experiments

    NASA Astrophysics Data System (ADS)

    Garcia, Daniel B.; Dattelbaum, Dana M.; Goodwin, Peter M.; Sheffield, Stephen A.; Morris, John S.; Gustavsen, Richard L.; Burkett, Michael W.

    2017-01-01

    The lack of published Ar gas shock data motivated an evaluation of the Ar Equation of State (EOS) in gas phase initial density regimes. In particular, these regimes include initial pressures in the range of 13.8 - 34.5 bar (0.025 - 0.056 g/ cm3) and initial shock velocities around 0.2 cm/μs. The objective of the numerical evaluation was to develop a physical understanding of the EOS behavior of shocked and subsequently multiply re-shocked Ar gas through Pagosa numerical simulations utilizing the SESAME equation of state. Pagosa is a Los Alamos National Laboratory 2-D and 3-D Eulerian continuum dynamics code capable of modeling high velocity compressible flow with multiple materials. The approach involved the use of gas gun experiments to evaluate the shock and multiple re-shock behavior of pressurized Ar gas to validate Pagosa simulations and the SESAME EOS. Additionally, the diagnostic capability within the experiments allowed for the EOS to be fully constrained with measured shock velocity, particle velocity and temperature. The simulations demonstrate excellent agreement with the experiments in the shock velocity/particle velocity space, and reasonable comparisons for the ionization temperatures.

  10. Crack-Detection Experiments on Simulated Turbine Engine Disks in NASA Glenn Research Center's Rotordynamics Laboratory

    NASA Technical Reports Server (NTRS)

    Woike, Mark R.; Abdul-Aziz, Ali

    2010-01-01

    The development of new health-monitoring techniques requires the use of theoretical and experimental tools to allow new concepts to be demonstrated and validated prior to use on more complicated and expensive engine hardware. In order to meet this need, significant upgrades were made to NASA Glenn Research Center s Rotordynamics Laboratory and a series of tests were conducted on simulated turbine engine disks as a means of demonstrating potential crack-detection techniques. The Rotordynamics Laboratory consists of a high-precision spin rig that can rotate subscale engine disks at speeds up to 12,000 rpm. The crack-detection experiment involved introducing a notch on a subscale engine disk and measuring its vibration response using externally mounted blade-tip-clearance sensors as the disk was operated at speeds up to 12 000 rpm. Testing was accomplished on both a clean baseline disk and a disk with an artificial crack: a 50.8-mm- (2-in.-) long introduced notch. The disk s vibration responses were compared and evaluated against theoretical models to investigate how successful the technique was in detecting cracks. This paper presents the capabilities of the Rotordynamics Laboratory, the baseline theory and experimental setup for the crack-detection experiments, and the associated results from the latest test campaign.

  11. Corneal hyper-viscoelastic model: derivations, experiments, and simulations.

    PubMed

    Su, Peng; Yang, Yang; Xiao, Jingjing; Song, Yanming

    2015-01-01

    The aim of this study is to propose a method to construct corneal biomechanical model which is the foundation for simulation of corneal microsurgery. Corneal material has two significant characteristics: hyperelastic and viscoelastic. Firstly, Mooney-Rivlin hyperelastic model of cornea obtained based on stored-energy function can be simplified as a linear equation with two unknown parameters. Then, modified Maxwell viscoelastic model of the cornea, whose analytical form is consistent with the generalized Prony-series model, is proposed from the perspective of material mechanics. Parameters of the model are determined by the uniaxial tensile tests and the stress-relaxation tests. Corneal material properties are simulated to verify the hyper-viscoelastic model and measure the effectiveness of the model in the finite element simulation. On this basis, an in vivo model of the corneal is built. And the simulation of extrusion in vivo cornea shows that the force is roughly nonlinearly increasing with displacement, and it is consistent with the results obtained by extrusion experiment of in vivo cornea. Conlusions: This paper derives a corneal hyper-viscoelastic model to describe the material properties more accurately, and explains the mathematical method for determination of the model parameters. The model is an effective biomechanical model, which can be directly used for simulation of trephine and suture in keratoplasty. Although the corneal hyper-viscoelastic model is taken as the object of study, the method has certain adaptability in biomechanical research of ophthalmology.

  12. Simulation experiences of paramedic students: a cross-cultural examination.

    PubMed

    Williams, Brett; Abel, Chloe; Khasawneh, Eihab; Ross, Linda; Levett-Jones, Tracy

    2016-01-01

    Simulation-based education is an important part of paramedic education and training. While accessing clinical placements that are adequate in quality and quantity continues to be challenging, simulation is being recognized by paramedic academics as a potential alternative. Examining students' satisfaction of simulation, particularly cross-culturally is therefore important in providing feedback to academic teaching staff and the international paramedic community. This study aimed to compare simulation satisfaction among paramedic students from universities in Australia and Jordan. A cross-sectional study using a paper-based English version of the Satisfaction with Simulation Experience Scale was administered to paramedic students from all year levels. A total of 511 students participated in this study; 306 students (60%) from Australia (Monash University) and 205 students (40%) from Jordan (Jordan University of Science and Technology). There were statistically significant differences with large effect size noted in all three original factors between Australian and Jordanian students: debrief and feedback (mean =38.66 vs mean =34.15; P<0.001; d=0.86), clinical reasoning (mean =21.32 vs mean =18.28; P<0.001; d=0.90), and clinical learning (mean =17.59 vs mean =15.47; P<0.001; d=1.12). This study has demonstrated that simulation education is generally well received by students in Australia and Jordan although Australian students reported having higher satisfaction levels then their Jordanian counterparts. These results provide important data for paramedic educators involved in simulation-based education and training in Australia and Jordan and pave the way for other cross-cultural examinations to be explored.

  13. Combustion-Powered Actuation for Dynamic Stall Suppression - Simulations and Low-Mach Experiments

    NASA Technical Reports Server (NTRS)

    Matalanis, Claude G.; Min, Byung-Young; Bowles, Patrick O.; Jee, Solkeun; Wake, Brian E.; Crittenden, Tom; Woo, George; Glezer, Ari

    2014-01-01

    An investigation on dynamic-stall suppression capabilities of combustion-powered actuation (COMPACT) applied to a tabbed VR-12 airfoil is presented. In the first section, results from computational fluid dynamics (CFD) simulations carried out at Mach numbers from 0.3 to 0.5 are presented. Several geometric parameters are varied including the slot chordwise location and angle. Actuation pulse amplitude, frequency, and timing are also varied. The simulations suggest that cycle-averaged lift increases of approximately 4% and 8% with respect to the baseline airfoil are possible at Mach numbers of 0.4 and 0.3 for deep and near-deep dynamic-stall conditions. In the second section, static-stall results from low-speed wind-tunnel experiments are presented. Low-speed experiments and high-speed CFD suggest that slots oriented tangential to the airfoil surface produce stronger benefits than slots oriented normal to the chordline. Low-speed experiments confirm that chordwise slot locations suitable for Mach 0.3-0.4 stall suppression (based on CFD) will also be effective at lower Mach numbers.

  14. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    NASA Astrophysics Data System (ADS)

    Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

    2015-11-01

    Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

  15. Dynamics and control simulation of the Spacelab Experiment Pointing Mount

    NASA Technical Reports Server (NTRS)

    Marsh, E. L.; Ward, R. S.

    1977-01-01

    Computer simulations were developed to evaluate the performance of four Experiment Pointing Mounts (EPM) being considered for Spacelab experiments in the 1980-1990 time frame. The system modeled compromises a multibody system consisting of the shuttle, a mechanical isolation device, the EPM, celestial and inertial sensors, bearings, gimbal torque motors and associated nonlinearities, the experiment payload, and control and estimator algorithms. Each mount was subjected to a common disturbance (shuttle vernier thruster firing and man push off) and command (stellar pointing or solar raster scan) input. The fundamental limitation common to all mounts was found to be sensor noise. System dynamics and hardware nonlinearities have secondary effects on pointing performance for sufficiently high bandwidth.

  16. Dynamics and control simulation of the Spacelab Experiment Pointing Mount

    NASA Technical Reports Server (NTRS)

    Marsh, E. L.; Ward, R. S.

    1977-01-01

    Computer simulations were developed to evaluate the performance of four Experiment Pointing Mounts (EPM) being considered for Spacelab experiments in the 1980-1990 time frame. The system modeled compromises a multibody system consisting of the shuttle, a mechanical isolation device, the EPM, celestial and inertial sensors, bearings, gimbal torque motors and associated nonlinearities, the experiment payload, and control and estimator algorithms. Each mount was subjected to a common disturbance (shuttle vernier thruster firing and man push off) and command (stellar pointing or solar raster scan) input. The fundamental limitation common to all mounts was found to be sensor noise. System dynamics and hardware nonlinearities have secondary effects on pointing performance for sufficiently high bandwidth.

  17. DSMC Simulations of Hypersonic Flows and Comparison With Experiments

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Bird, Graeme A.; Markelov, Gennady N.

    2004-01-01

    This paper presents computational results obtained with the direct simulation Monte Carlo (DSMC) method for several biconic test cases in which shock interactions and flow separation-reattachment are key features of the flow. Recent ground-based experiments have been performed for several biconic configurations, and surface heating rate and pressure measurements have been proposed for code validation studies. The present focus is to expand on the current validating activities for a relatively new DSMC code called DS2V that Bird (second author) has developed. Comparisons with experiments and other computations help clarify the agreement currently being achieved between computations and experiments and to identify the range of measurement variability of the proposed validation data when benchmarked with respect to the current computations. For the test cases with significant vibrational nonequilibrium, the effect of the vibrational energy surface accommodation on heating and other quantities is demonstrated.

  18. Simulations of NOVA direct-drive Rayleigh-Taylor experiments

    SciTech Connect

    Weber, S.V.

    1990-11-03

    Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. These experiments employ beams smoothed with random phase plates (RPP), and will later include smoothing by spectral dispersion (SSD). Samples are CH foils with or without imposed sinusoidal surface perturbations. Perturbation growth is diagnosed by means of x-ray backlighting. Calculated growth rates are fairly flat across the wavelength range of 20--80 {mu}m which can be accessed experimentally, and are moderately suppressed below classical growth rates. Perturbations of large enough initial amplitude that the contrast in the x-ray image is measurable from the start of the experiment quickly grow into the nonlinear regime. Smaller initial amplitudes result in a longer interval of linear growth, but the initial perturbation will not be detectable in the data. Structure which is predicted to develop from speckles in the RPP beam pattern, with and without SSD, is also presented.

  19. GPR Experiments of the Simulated Cavity Detection in Urban Areas

    NASA Astrophysics Data System (ADS)

    Kim, Changryol; Kang, Woong; Son, Jeongsul; Jeong, Soocheol

    2017-04-01

    Recent years, the deteriorated underground facilities such as sewage or water supply pipes have increased significantly with growing urban development in Korea. The soils surrounding old damaged pipes were washed away beneath the roadbed, causing underground cavities and eventual ground cave-ins in the urban areas. The detection of the roadbed cavities is, therefore, required to prevent property damage and loss of human lives for precautionary measures. In general, GPR is well known as a suitable geophysical technique for shallow underground cavity detection. 3-D GPR technique was applied to conduct the full-scale experiment for roadbed cavity detection. The physical experiment has employed the testing ground with soil characteristics of silty sand soils. The experimental test ground consists of physically simulated cavities with dome-shaped structure, and of hume concrete and cast-iron pipes to simulate underground facilities. The pipes were installed more than one meter below the land surface and simulated cavities nearby were also installed at regular intervals in spatial distribution. The land surface of the site was not paved with asphalt concrete at the current stage of the experiments. The GPR data was obtained to investigate GPR responses due to different antenna orientations (HH and VV antenna orientations) over the testing ground. The results of the experiment show that the reflection patterns from the simulated cavities are hyperbolic returns typical to the point source in 2-D perspective. The different antenna orientations have shown the different areal extents of the hyperbolic reflections patterns from the cavities, and have shown the different characteristics over the pipes on the data. A closer inspection of 3-D GPR volume data has yielded more clear interpretation than 2-D GPR data regarding where the cavities are situated and what kind of shape the cavities show in space. This study is an ongoing project of KIGAM at a second stage of the physical

  20. Complete Monte Carlo Simulation of Neutron Scattering Experiments

    SciTech Connect

    Drosg, M.

    2011-12-13

    In the far past, it was not possible to accurately correct for the finite geometry and the finite sample size of a neutron scattering set-up. The limited calculation power of the ancient computers as well as the lack of powerful Monte Carlo codes and the limitation in the data base available then prevented a complete simulation of the actual experiment. Using e.g. the Monte Carlo neutron transport code MCNPX [1], neutron scattering experiments can be simulated almost completely with a high degree of precision using a modern PC, which has a computing power that is ten thousand times that of a super computer of the early 1970s. Thus, (better) corrections can also be obtained easily for previous published data provided that these experiments are sufficiently well documented. Better knowledge of reference data (e.g. atomic mass, relativistic correction, and monitor cross sections) further contributes to data improvement. Elastic neutron scattering experiments from liquid samples of the helium isotopes performed around 1970 at LANL happen to be very well documented. Considering that the cryogenic targets are expensive and complicated, it is certainly worthwhile to improve these data by correcting them using this comparatively straightforward method. As two thirds of all differential scattering cross section data of {sup 3}He(n,n){sup 3}He are connected to the LANL data, it became necessary to correct the dependent data measured in Karlsruhe, Germany, as well. A thorough simulation of both the LANL experiments and the Karlsruhe experiment is presented, starting from the neutron production, followed by the interaction in the air, the interaction with the cryostat structure, and finally the scattering medium itself. In addition, scattering from the hydrogen reference sample was simulated. For the LANL data, the multiple scattering corrections are smaller by a factor of five at least, making this work relevant. Even more important are the corrections to the Karlsruhe data

  1. Computer simulation models are implementable as replacements for animal experiments.

    PubMed

    Badyal, Dinesh K; Modgill, Vikas; Kaur, Jasleen

    2009-04-01

    It has become increasingly difficult to perform animal experiments, because of issues related to the procurement of animals, and strict regulations and ethical issues related to their use. As a result, it is felt that the teaching of pharmacology should be more clinically oriented and that unnecessary animal experimentation should be avoided. Although a number of computer simulation models (CSMs) are available, they are not being widely used. Interactive demonstrations were conducted to encourage the departmental faculty to use CSMs. Four different animal experiments were selected, that dealt with actions of autonomic drugs. The students observed demonstrations of animal experiments involving conventional methods and the use of CSMs. This was followed by hands-on experience of the same experiment, but using CSMs in small groups, instead of hands-on experience with the animal procedures. Test scores and feedback showed that there was better understanding of the mechanisms of action of the drugs, gained in a shorter time. The majority of the students found the teaching programme used to be good to excellent. CSMs can be used repeatedly and independently by students, and this avoids unnecessary experimentation and also causing pain and trauma to animals. The CSM programme can be implemented in existing teaching schedules for pharmacology undergraduate teaching with basic infrastructure support, and is readily adaptable for use by other institutes.

  2. Numerical Simulation of Indirect-Drive Tracer Diagnostic Experiments

    NASA Astrophysics Data System (ADS)

    Macfarlane, J. J.; Cohen, D. H.; Wang, P.; Jaanimagi, P.; Back, C. A.; Landen, O. L.; Turner, R. E.; Oertel, J. A.; Nash, T. J.

    1998-11-01

    We have performed indirect-drive experiments at the OMEGA (U. Rochester) and NOVA (LLNL) laser facilities to study the use of tracer emission and absorption spectroscopy in characterizing radiatively-driven materials. In these experiments, thin ( ~ 3000 Åthick) tracer layers of KCl, KF, and NaCl were embedded in ~ 50 -- 100 μm-thick Al and Ge-doped CH ``witness plates'' which were attached to the side of cylindrical Au hohlraums. In most cases the hohlraums were irradiated with 12 -- 25 TW, 1 ns square laser pulses, which generate a high-TR radiation drive (TR ≈ 200 eV). In some experiments, shaped laser pulses were used. The radiation wave burns into the witness plate, heating the tracer to temperatures of 100 -- 200 eV. In emission spectroscopy experiments performed using a Hettrick soft x-ray spectrometer,(Back et al., and Cohen et al. APS DPP Meeting 1997.) (hν ~ 300 - 900 eV; λ/Δλ ~ 500), K, Cl, and F emission lines were observed above the continuum of the Al witness plate. Absorption spectroscopy experiments at OMEGA are scheduled to be performed in August 1998.(Cohen et al., this meeting.) We will present results from numerical simulations of these experiments, utilizing non-LTE collisional-radiative, radiation-hydrodynamics, and 3-D view factor codes.

  3. Physics potential of a long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and Hyper-Kamiokande

    NASA Astrophysics Data System (ADS)

    Abe, K.; Aihara, H.; Andreopoulos, C.; Anghel, I.; Ariga, A.; Ariga, T.; Asfandiyarov, R.; Askins, M.; Back, J. J.; Ballett, P.; Barbi, M.; Barker, G. J.; Barr, G.; Bay, F.; Beltrame, P.; Berardi, V.; Bergevin, M.; Berkman, S.; Berry, T.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bolognesi, S.; Boyd, S. B.; Bravar, A.; Bronner, C.; Cafagna, F. S.; Carminati, G.; Cartwright, S. L.; Catanesi, M. G.; Choi, K.; Choi, J. H.; Collazuol, G.; Cowan, G.; Cremonesi, L.; Davies, G.; De Rosa, G.; Densham, C.; Detwiler, J.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Emery, S.; Ereditato, A.; Fernández, P.; Feusels, T.; Finch, A.; Fitton, M.; Friend, M.; Fujii, Y.; Fukuda, Y.; Fukuda, D.; Galymov, V.; Ganezer, K.; Gonin, M.; Gumplinger, P.; Hadley, D. R.; Haegel, L.; Haesler, A.; Haga, Y.; Hartfiel, B.; Hartz, M.; Hayato, Y.; Hierholzer, M.; Hill, J.; Himmel, A.; Hirota, S.; Horiuchi, S.; Huang, K.; Ichikawa, A. K.; Iijima, T.; Ikeda, M.; Imber, J.; Inoue, K.; Insler, J.; Intonti, R. A.; Irvine, T.; Ishida, T.; Ishino, H.; Ishitsuka, M.; Itow, Y.; Izmaylov, A.; Jamieson, B.; Jang, H. I.; Jiang, M.; Joo, K. K.; Jung, C. K.; Kaboth, A.; Kajita, T.; Kameda, J.; Karadhzov, Y.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kim, J. Y.; Kim, S. B.; Kishimoto, Y.; Kobayashi, T.; Koga, M.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W. R.; Kudenko, Y.; Kutter, T.; Kuze, M.; Labarga, L.; Lagoda, J.; Laveder, M.; Lawe, M.; Learned, J. G.; Lim, I. T.; Lindner, T.; Longhin, A.; Ludovici, L.; Ma, W.; Magaletti, L.; Mahn, K.; Malek, M.; Mariani, C.; Marti, L.; Martin, J. F.; Martin, C.; Martins, P. P. J.; Mazzucato, E.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mezzetto, M.; Minakata, H.; Minamino, A.; Mine, S.; Mineev, O.; Miura, M.; Monroe, J.; Mori, T.; Moriyama, S.; Mueller, T.; Muheim, F.; Nakahata, M.; Nakamura, K.; Nakaya, T.; Nakayama, S.; Needham, M.; Nicholls, T.; Nirkko, M.; Nishimura, Y.; Noah, E.; Nowak, J.; Nunokawa, H.; O'Keeffe, H. M.; Okajima, Y.; Okumura, K.; Oser, S. M.; O'Sullivan, E.; Ovsiannikova, T.; Owen, R. A.; Oyama, Y.; Pérez, J.; Pac, M. Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perevozchikov, O.; Perkin, J. D.; Pistillo, C.; Playfer, S.; Posiadala-Zezula, M.; Poutissou, J.-M.; Quilain, B.; Quinto, M.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A.; Redij, A.; Retiere, F.; Riccio, C.; Richard, E.; Rondio, E.; Rose, H. J.; Ross-Lonergan, M.; Rott, C.; Rountree, S. D.; Rubbia, A.; Sacco, R.; Sakuda, M.; Sanchez, M. C.; Scantamburlo, E.; Scholberg, K.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Shaikhiev, A.; Shimizu, I.; Shiozawa, M.; Short, S.; Sinnis, G.; Smy, M. B.; Sobczyk, J.; Sobel, H. W.; Stewart, T.; Stone, J. L.; Suda, Y.; Suzuki, Y.; Suzuki, A. T.; Svoboda, R.; Tacik, R.; Takeda, A.; Taketa, A.; Takeuchi, Y.; Tanaka, H. A.; Tanaka, H. K. M.; Tanaka, H.; Terri, R.; Thompson, L. F.; Thorpe, M.; Tobayama, S.; Tolich, N.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vagins, M. R.; Vasseur, G.; Vogelaar, R. B.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilson, J. R.; Xin, T.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Zito, M.

    2015-05-01

    Hyper-Kamiokande will be a next-generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of Hyper-Kamiokande is the study of CP asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this paper, the physics potential of a long-baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis uses the framework and systematic uncertainties derived from the ongoing T2K experiment. With a total exposure of 7.5 MW × 10^7s integrated proton beam power (corresponding to 1.56 × 10^{22} protons on target with a 30 GeV proton beam) to a 2.5^circ off-axis neutrino beam, it is expected that the leptonic CP phase δ _{CP} can be determined to better than 19 degrees for all possible values of δ _{CP}, and CP violation can be established with a statistical significance of more than 3 σ (5 σ) for 76{%} (58{%}) of the {δ _{CP}} parameter space. Using both ν _e appearance and ν _μ disappearance data, the expected 1σ uncertainty of sin ^2θ _{23} is 0.015(0.006) for sin ^2θ _{23}=0.5(0.45).

  4. Analysis of sensor network observations during some simulated landslide experiments

    NASA Astrophysics Data System (ADS)

    Scaioni, M.; Lu, P.; Feng, T.; Chen, W.; Wu, H.; Qiao, G.; Liu, C.; Tong, X.; Li, R.

    2012-12-01

    A multi-sensor network was tested during some experiments on a landslide simulation platform established at Tongji University (Shanghai, P.R. China). Here landslides were triggered by means of artificial rainfall (see Figure 1). The sensor network currently incorporates contact sensors and two imaging systems. This represent a novel solution, because the spatial sensor network incorporate either contact sensors and remote sensors (video-cameras). In future, these sensors will be installed on two real ground slopes in Sichuan province (South-West China), where Wenchuan earthquake occurred in 2008. This earthquake caused the immediate activation of several landslide, while other area became unstable and still are a menace for people and properties. The platform incorporates the reconstructed scale slope, sensor network, communication system, database and visualization system. Some landslide simulation experiments allowed ascertaining which sensors could be more suitable to be deployed in Wenchuan area. The poster will focus on the analysis of results coming from down scale simulations. Here the different steps of the landslide evolution can be followed on the basis of sensor observations. This include underground sensors to detect the water table level and the pressure in the ground, a set of accelerometers and two inclinometers. In the first part of the analysis the full data series are investigated to look for correlations and common patterns, as well as to link them to the physical processes. In the second, 4 subsets of sensors located in neighbor positions are analyzed. The analysis of low- and high-speed image sequences allowed to track a dense field of displacement on the slope surface. These outcomes have been compared to the ones obtained from accelerometers for cross-validation. Images were also used for the photogrammetric reconstruction of the slope topography during the experiment. Consequently, volume computation and mass movements could be evaluated on

  5. Engineering and simulation of life sciences Spacelab experiments

    NASA Technical Reports Server (NTRS)

    Johnston, R. S.; Bush, W. H. Jr; Rummel, J. A.; Alexander, W. C.

    1979-01-01

    The third in a series of Spacelab Mission Development tests was conducted at the Johnson (correction of Johnston) Space Center as a part of the development of Life Sciences experiments for the Space Shuttle era. The latest test was a joint effort of the Ames Research and Johnson Space Centers and utilized animals and men for study. The basic objective of this test was to evaluate the operational concepts planned for the Space Shuttle life science payloads program. A three-man crew (Mission Specialist and two Payload Specialists) conducted 26 experiments and 12 operational tests, which were selected for this 7-day mission simulation. The crew lived on board a simulated Orbiter/Spacelab mockup 24 hr a day. The Orbiter section contained the mid deck crew quarters area, complete with sleeping, galley and waste management provisions. The Spacelab was identical in geometry to the European Space Agency Spacelab design, complete with removable rack sections and stowage provisions. Communications between the crewmen and support personnel were configured and controlled as currently planned for operational shuttle flights. For this test a Science Operations Remote Center was manned at the Ames Research Center and was managed by simulated Mission Control and Payload Operation Control Centers at the Johnson Space Center. This paper presents the test objectives, description of the facilities and test program, and the results of this test.

  6. Engineering and simulation of life sciences Spacelab experiments

    NASA Technical Reports Server (NTRS)

    Johnston, R. S.; Bush, W. H. Jr; Rummel, J. A.; Alexander, W. C.

    1979-01-01

    The third in a series of Spacelab Mission Development tests was conducted at the Johnson (correction of Johnston) Space Center as a part of the development of Life Sciences experiments for the Space Shuttle era. The latest test was a joint effort of the Ames Research and Johnson Space Centers and utilized animals and men for study. The basic objective of this test was to evaluate the operational concepts planned for the Space Shuttle life science payloads program. A three-man crew (Mission Specialist and two Payload Specialists) conducted 26 experiments and 12 operational tests, which were selected for this 7-day mission simulation. The crew lived on board a simulated Orbiter/Spacelab mockup 24 hr a day. The Orbiter section contained the mid deck crew quarters area, complete with sleeping, galley and waste management provisions. The Spacelab was identical in geometry to the European Space Agency Spacelab design, complete with removable rack sections and stowage provisions. Communications between the crewmen and support personnel were configured and controlled as currently planned for operational shuttle flights. For this test a Science Operations Remote Center was manned at the Ames Research Center and was managed by simulated Mission Control and Payload Operation Control Centers at the Johnson Space Center. This paper presents the test objectives, description of the facilities and test program, and the results of this test.

  7. Engineering and simulation of life sciences Spacelab experiments.

    PubMed

    Johnston, R S; Bush, W H; Rummel, J A; Alexander, W C

    1979-10-01

    The third in a series of Spacelab Mission Development tests was conducted at the Johnson (correction of Johnston) Space Center as a part of the development of Life Sciences experiments for the Space Shuttle era. The latest test was a joint effort of the Ames Research and Johnson Space Centers and utilized animals and men for study. The basic objective of this test was to evaluate the operational concepts planned for the Space Shuttle life science payloads program. A three-man crew (Mission Specialist and two Payload Specialists) conducted 26 experiments and 12 operational tests, which were selected for this 7-day mission simulation. The crew lived on board a simulated Orbiter/Spacelab mockup 24 hr a day. The Orbiter section contained the mid deck crew quarters area, complete with sleeping, galley and waste management provisions. The Spacelab was identical in geometry to the European Space Agency Spacelab design, complete with removable rack sections and stowage provisions. Communications between the crewmen and support personnel were configured and controlled as currently planned for operational shuttle flights. For this test a Science Operations Remote Center was manned at the Ames Research Center and was managed by simulated Mission Control and Payload Operation Control Centers at the Johnson Space Center. This paper presents the test objectives, description of the facilities and test program, and the results of this test.

  8. Extending a Flight Management Computer for Simulation and Flight Experiments

    NASA Technical Reports Server (NTRS)

    Madden, Michael M.; Sugden, Paul C.

    2005-01-01

    In modern transport aircraft, the flight management computer (FMC) has evolved from a flight planning aid to an important hub for pilot information and origin-to-destination optimization of flight performance. Current trends indicate increasing roles of the FMC in aviation safety, aviation security, increasing airport capacity, and improving environmental impact from aircraft. Related research conducted at the Langley Research Center (LaRC) often requires functional extension of a modern, full-featured FMC. Ideally, transport simulations would include an FMC simulation that could be tailored and extended for experiments. However, due to the complexity of a modern FMC, a large investment (millions of dollars over several years) and scarce domain knowledge are needed to create such a simulation for transport aircraft. As an intermediate alternative, the Flight Research Services Directorate (FRSD) at LaRC created a set of reusable software products to extend flight management functionality upstream of a Boeing-757 FMC, transparently simulating or sharing its operator interfaces. The paper details the design of these products and highlights their use on NASA projects.

  9. Modeling, simulation, and experiments of coating growth on nanofibers

    NASA Astrophysics Data System (ADS)

    Clemons, C. B.; Hamrick, P.; Heminger, J.; Kreider, K. L.; Young, G. W.; Buldum, A.; Evans, E.; Zhang, G.

    2008-02-01

    This work is a comparison of modeling and simulation results with experiments for an integrated experimental/modeling investigation of a procedure to coat nanofibers and core-clad nanostructures with thin film materials using plasma enhanced physical vapor deposition. In the experimental effort, electrospun polymer nanofibers are coated with metallic materials under different operating conditions to observe changes in the coating morphology. The modeling effort focuses on linking simple models at the reactor level, nanofiber level and atomic level to form a comprehensive model. The comprehensive model leads to the definition of an evolution equation for the coating free surface around an isolated nanofiber. This evolution equation was previously derived and solved under conditions of a nearly circular coating, with a concentration field that was only radially dependent and that was independent of the location of the coating free surface. These assumptions permitted the development of analytical expressions for the concentration field. The present work does not impose the above-mentioned conditions and considers numerical simulations of the concentration field that couple with level set simulations of the evolution equation for the coating free surface. Further, the cases of coating an isolated fiber as well as a multiple fiber mat are considered. Simulation results are compared with experimental results as the reactor pressure and power, as well as the nanofiber mat porosity, are varied.

  10. Comparing MHD simulations of RFP plasmas to RELAX experiments

    NASA Astrophysics Data System (ADS)

    McCollam, K. J.; den Hartog, D. J.; Jacobson, C. M.; Sauppe, J. P.; Masamune, S.; Sanpei, A.

    2015-11-01

    Standard reversed-field pinch (RFP) plasmas provide a nonlinear dynamical system as a validation domain for numerical MHD simulation codes, which can be applied to general toroidal confinement scenarios including tokamaks. Using the NIMROD code, we calculate linear stability and simulate the nonlinear evolution of plasmas similar to those in the RELAX RFP experiment, whose relatively modest Lundquist numbers of order 104 make the simulations tractable given present computing resources. The chosen RELAX cases cover a broad range of RFP reversal parameters and have also been previously simulated with the MIPS code (N. Mizuguchi et al., TH/P3-26, IAEA FEC, 2012). Experimental diagnostics that can be used for validation purposes include Thomson scattering for electron temperature, interferometry for electron density, SXR imaging, and external and internal magnetic probes. RELAX's small aspect ratio (~ 2) motivates a comparison study using toroidal and cylindrical geometries in NIMROD. This work is supported by the U.S. DOE and NSF and by the Japan Society for the Promotion of Science.

  11. Granular Solid-liquid Transition: Experiment and Simulation

    NASA Astrophysics Data System (ADS)

    Fei, M.; Xu, X.; Sun, Q.

    2015-12-01

    Granular media are amorphous materials, which differs from traditional solid or liquid. In different circumstance, granular behavior varies from solid-like to liquid-like, and the transitions between these regimes are always related to many complex natural progresses such as the failure of soil foundation and the occurrence of landslide and debris flow. The mechanic of elastic instability during the transition from solid-like to liquid-like regime, and the quantitative description of irreversible deformation during flow are the key problems to interpret these transition phenomena. In this work, we developed a continuum model with elastic stable condition and irreversible flow rule of granular material based on a thermal dynamical model, the Two-Granular-Temperature model (TGT). Since infinitesimal elastic deformation in solid-like regime and significant plastic large deformation in liquid-like regime can coexist in the granular solid-liquid transition process, the material point method (MPM) was used to build an effective numerical model. Collapse of rectangular granular pile contains both the transition from granular solid to granular liquid and the inverse process, thus in this work we carried out collapse experiment with clay particles, and simulated the experiment with our continuum model and an open-source DEM model YADE to study the transition processes. Results between experiment and simulations were compared and good agreements on collapse shape and velocity profiles were achieved, and the new model proposed in this work seems to work well on the description of granular solid-liquid transition.

  12. Advanced Diagnostic Design for Paul Trap Simulator Experiment (PTSX)

    NASA Astrophysics Data System (ADS)

    Godbehere, A. B.; Chung, M.; Davidson, R. C.; Gilson, E. P.

    2007-11-01

    The Paul Trap Simulator Experiment (PTSX) is a compact laboratory Paul trap that uses a pure-ion plasma to simulate a long, thin charged particle bunch coasting through a kilometers-long magnetic alternating-gradient transport system. Current PTSX experiments are exploring the limits of the smooth focusing model, and using the detection of collective mode oscillations to infer key bunch properties such as the line density and transverse temperature. These experiments require the use of advanced diagnostics to measure the transverse distribution of the plasma perticles at a given instant in time. One set of experimental diagnostics uses a CCD camera with a short exposure time to collect light from Laser Induced Fluorescence (LIF) of the cross section of a barium plasma beam. A second set of experimental diagnostics utilizes capacitive coupling of the ions with four electrodes, which are connected to high- input-impedance active filters. Details of the design and performance of the laser system, CCD camera system, and collective mode diagnostic electronics will be presented.

  13. Theory and Simulation of the LBNL Plasma Lens Experiment

    NASA Astrophysics Data System (ADS)

    Backhaus, E. Yu.; Wurtele, J. S.; Govil, R.; Leemans, W. P.

    1998-11-01

    A theoretical analysis and Particle-in-cell (PIC) simulation of the LBNL plasma lens experiment is presented. The envelope equation is used which includes the self-consistent evolution of the beam (i.e. `thick lens' effect), effects of nonlinear aberrations and full plasma return currents.(R. Govil and W.P.Leemans, proceedings of 8th workshop on advanced accelerator concepts.)^,(E. Yu. Backhaus, D. Whittum and J. S.Wurtele, proceedings of 8th workshop on advanced accelerator concepts.) The envelope equation is simplified in the limit of small k_pσ_r. It is shown that the effects of the aberrations can be of the same order as the effect of the return currents for k_pσ_r<=0.5. The full envelope equation is used to model the experiment for a wide range of k_pσ_r. The 2D relativistic, fully electromagnetic PIC code (XOOPIC) is used to simulate the experiment including the finite plasma effect. The validity of the envelope equation is discussed.

  14. Ground based simulation of life sciences Spacelab experiments

    NASA Technical Reports Server (NTRS)

    Rummel, J. A.; Alexander, W. C.; Bush, W. H.; Johnston, R. S.

    1978-01-01

    The third in a series of Spacelab Mission Development tests was a joint effort of the Ames Research and Johnson Space Centers to evaluate planned operational concepts of the Space Shuttle life sciences program. A three-man crew conducted 26 experiments and 12 operational tests, utilizing both human and animal subjects. The crew lived aboard an Orbiter/Spacelab mockup for the seven-day simulation. The Spacelab was identical in geometry to the European Space Agency design, complete with removable rack sections and stowage provisions. Communications were controlled as currently planned for operational Shuttle flights. A Science Operations Remote Center at the Ames Research Center was managed by simulated Mission Control and Payload Operation Control Centers at the Johnson Space Center. This paper presents the test objectives, describes the facilities and test program, and outlines the results of this test.

  15. Radial correlation length across magnetic islands: Simulations and experiments

    NASA Astrophysics Data System (ADS)

    Fernández-Marina, F.; Estrada, T.; Blanco, E.; García, L.

    2017-07-01

    The turbulence radial correlation length Lr of density fluctuations is studied across magnetic islands both numerically and experimentally. The numerical study has been carried out by a resistive MHD code (called FAR). It shows asymmetric Lr profiles when measured across magnetic islands. Subsequent simulations using a synthetic Doppler reflectometer suggest that this diagnostic has the capability to capture the effect observed in the results provided by FAR. Finally, experimental studies performed using the Doppler reflectometer installed at the TJ-II stellarator show asymmetries in the coherence profiles matching the radial position of magnetic islands. The similarities found between simulations and experiments indicate that radial correlation length measurements could be used to detect magnetic islands in fusion plasmas.

  16. Neon dc glow discharge at cryogenic cooling: experiment and simulation

    NASA Astrophysics Data System (ADS)

    Shumova, V. V.; Polyakov, D. N.; Vasilyak, L. M.

    2017-10-01

    The results of the measurement and simulation of electrical characteristics of neon dc discharge are presented. These results have been obtained in the discharge cooled to the temperature of liquid nitrogen (77 K). The experiments were carried out at a neon pressure of 18–187 Pa and a discharge current of 0.01–3.5 mA. Cooling in the subnormal discharge mode at a constant value of discharge current led to a change in the discharge mode. When cooled, the electric field in the positive column and at the boundary of the transition to the normal discharge increased, and the reduced electric field decreased in all the investigated ranges of discharge current, pressure and neon concentration. The simulation of the positive column, based on the diffusion-drift (fluid) model, has shown that the input in the ionization of processes involving excited atoms increases with decreasing discharge temperature.

  17. The TESS (Tandem Experiment Simulation Studies) computer code user's manual

    SciTech Connect

    Procassini, R.J. . Dept. of Nuclear Engineering); Cohen, B.I. )

    1990-06-01

    TESS (Tandem Experiment Simulation Studies) is a one-dimensional, bounded particle-in-cell (PIC) simulation code designed to investigate the confinement and transport of plasma in a magnetic mirror device, including tandem mirror configurations. Mirror plasmas may be modeled in a system which includes an applied magnetic field and/or a self-consistent or applied electrostatic potential. The PIC code TESS is similar to the PIC code DIPSI (Direct Implicit Plasma Surface Interactions) which is designed to study plasma transport to and interaction with a solid surface. The codes TESS and DIPSI are direct descendants of the PIC code ES1 that was created by A. B. Langdon. This document provides the user with a brief description of the methods used in the code and a tutorial on the use of the code. 10 refs., 2 tabs.

  18. Comparison of simulation with experiment in an RFQ

    SciTech Connect

    Boicourt, G.P.; Sander, O.R.; Wangler, T.P.

    1985-01-01

    The accelerator test stand (ATS) RFQ has provided an opportunity to compare the predictions of the RFQ beam-dynamics code PARMTEQ with actual operation of an RFQ. For this comparison, the code was adapted to simulate the measured operation parameters, which are somewhat different from those of the ideal design. A Monte Carlo code was written to provide input to PARMTEQ, based on measured input beam distributions. With these refinements, the code has given results that are in good agreement with measurements and has provided information leading to an explanation of an unexpected set of measurements. This paper describes the method used to generate a pseudo particle beam based on the measured transverse properties of the RFQ input beam and describes some of the comparisons between simulation and experiment. An explanation is provided for the energy-spectrum structure observed in the RFQ output beam during low-voltage operation. 3 refs., 7 figs.

  19. Gyrokinetic Simulation of Global Turbulent Transport Properties in Tokamak Experiments

    SciTech Connect

    Wang, W.X.; Lin, Z.; Tang, W.M.; Lee, W.W.; Ethier, S.; Lewandowski, J.L.V.; Rewoldt, G.; Hahm, T.S.; Manickam, J.

    2006-01-01

    A general geometry gyro-kinetic model for particle simulation of plasma turbulence in tokamak experiments is described. It incorporates the comprehensive influence of noncircular cross section, realistic plasma profiles, plasma rotation, neoclassical (equilibrium) electric fields, and Coulomb collisions. An interesting result of global turbulence development in a shaped tokamak plasma is presented with regard to nonlinear turbulence spreading into the linearly stable region. The mutual interaction between turbulence and zonal flows in collisionless plasmas is studied with a focus on identifying possible nonlinear saturation mechanisms for zonal flows. A bursting temporal behavior with a period longer than the geodesic acoustic oscillation period is observed even in a collisionless system. Our simulation results suggest that the zonal flows can drive turbulence. However, this process is too weak to be an effective zonal flow saturation mechanism.

  20. Ground based simulation of life sciences Spacelab experiments

    NASA Technical Reports Server (NTRS)

    Rummel, J. A.; Alexander, W. C.; Bush, W. H.; Johnston, R. S.

    1978-01-01

    The third in a series of Spacelab Mission Development tests was a joint effort of the Ames Research and Johnson Space Centers to evaluate planned operational concepts of the Space Shuttle life sciences program. A three-man crew conducted 26 experiments and 12 operational tests, utilizing both human and animal subjects. The crew lived aboard an Orbiter/Spacelab mockup for the seven-day simulation. The Spacelab was identical in geometry to the European Space Agency design, complete with removable rack sections and stowage provisions. Communications were controlled as currently planned for operational Shuttle flights. A Science Operations Remote Center at the Ames Research Center was managed by simulated Mission Control and Payload Operation Control Centers at the Johnson Space Center. This paper presents the test objectives, describes the facilities and test program, and outlines the results of this test.

  1. Wakefield Simulations for the Laser Acceleration Experiment at SLAC

    SciTech Connect

    Ng, Johnny

    2012-04-18

    Laser-driven acceleration in dielectric photonic band gap structures can provide gradients on the order of GeV/m. The small transverse dimension of the structure, on the order of the laser wavelength, presents interesting wakefield-related issues. Higher order modes can seriously degrade beam quality, and a detailed understanding is needed to mitigate such effects. On the other hand, wakefields also provide a direct way to probe the interaction of a relativistic bunch with the synchronous modes supported by the structure. Simulation studies have been carried out as part of the effort to understand the impact on beam dynamics, and to compare with data from beam experiments designed to characterize candidate structures. In this paper, we present simulation results of wakefields excited by a sub-wavelength bunch in optical photonic band gap structures.

  2. High-fidelity simulation in anesthesiology training: a survey of Canadian anesthesiology residents' simulator experience.

    PubMed

    Price, James W; Price, John R; Pratt, Dan D; Collins, John B; McDonald, Julie

    2010-02-01

    The objective of this survey was to explore Canadian anesthesiology residents' educational experience with high-fidelity simulation and to improve understanding of the factors perceived to have either a positive or a negative effect on residents' learning. In 2008, all Canadian anesthesiology residents (n = 599) were invited to complete a ten-minute anonymous online survey. Survey questions were derived from two sources, a literature search of MEDLINE (1966 to present), EMBASE (1980 to present), and the Cochrane and Campbell collaboration libraries and the experience of 25 pilot residents and the lead author. The survey response rate was 27.9% (n = 167). Junior residents (PGY1-3) responded that it would be helpful to have an introductory simulation course dealing with common intraoperative emergencies. The introduction of multidisciplinary scenarios (where nurses and colleagues from different specialties were involved in scenarios) was strongly supported. With respect to gender, male anesthesia residents indicated their comfort in making mistakes and asking for help in the simulator more frequently than female residents. In accordance with the ten Best Evidence Medical Education (BEME) principles of successful simulator education, Canadian centres could improve residents' opportunities for repetitive practice (with feedback), individualization of scenarios, and defined learning outcomes for scenarios. Anesthesiology residents indicate that simulation-based education is an anxiety provoking experience, but value its role in promoting safe practice and enhancing one's ability to deal with emergency situations. Suggestions to improve simulation training include increasing residents' access, adopting a more student-centred approach to learning, and creating a safer learning environment.

  3. The Impact of Baseline Trend Control on Visual Analysis of Single-Case Data

    ERIC Educational Resources Information Center

    Mercer, Sterett H.; Sterling, Heather E.

    2012-01-01

    The impact of baseline trend control on visual analyses of AB intervention graphs was examined with simulated data at various values of baseline trend, autocorrelation, and effect size. Participants included 202 undergraduate students with minimal training in visual analysis and 10 graduate students and faculty with more training and experience in…

  4. Non-robust numerical simulations of analogue extension experiments

    NASA Astrophysics Data System (ADS)

    Naliboff, John; Buiter, Susanne

    2016-04-01

    Numerical and analogue models of lithospheric deformation provide significant insight into the tectonic processes that lead to specific structural and geophysical observations. As these two types of models contain distinct assumptions and tradeoffs, investigations drawing conclusions from both can reveal robust links between first-order processes and observations. Recent studies have focused on detailed comparisons between numerical and analogue experiments in both compressional and extensional tectonics, sometimes involving multiple lithospheric deformation codes and analogue setups. While such comparisons often show good agreement on first-order deformation styles, results frequently diverge on second-order structures, such as shear zone dip angles or spacing, and in certain cases even on first-order structures. Here, we present finite-element experiments that are designed to directly reproduce analogue "sandbox" extension experiments at the cm-scale. We use material properties and boundary conditions that are directly taken from analogue experiments and use a Drucker-Prager failure model to simulate shear zone formation in sand. We find that our numerical experiments are highly sensitive to numerous numerical parameters. For example, changes to the numerical resolution, velocity convergence parameters and elemental viscosity averaging commonly produce significant changes in first- and second-order structures accommodating deformation. The sensitivity of the numerical simulations to small parameter changes likely reflects a number of factors, including, but not limited to, high angles of internal friction assigned to sand, complex, unknown interactions between the brittle sand (used as an upper crust equivalent) and viscous silicone (lower crust), highly non-linear strain weakening processes and poor constraints on the cohesion of sand. Our numerical-analogue comparison is hampered by (a) an incomplete knowledge of the fine details of sand failure and sand

  5. Simulating thin cirrus clouds in Observing System Simulation Experiments (OSSE) for LAWS. [Lidar Atmospheric Wind Sounder

    NASA Technical Reports Server (NTRS)

    Emmitt, G. D.; Wood, S. A.

    1991-01-01

    It was previously shown (Wood and Emmitt, 1990, 1991) that, by omitting the contribution of thin cirrus by the Observing System Simulation Experiments, will result in severe misrepresentation of both the frequency and the accuracy of wind observations in the upper troposphere. This paper estimates the presence of optically thin (tau less than 1.0) cirrus clouds by using model soundings in a cirrus cloud model. An example is presented showing the location of cirrus cloud profiles over North America for November 10, 1979, which were generated by the LAWS Simulation Model.

  6. Magnetohydrodynamic Simulation of Solid-Deuterium - Z-Pinch Experiments

    NASA Astrophysics Data System (ADS)

    Sheehey, Peter Trogdon

    Solid-deuterium-initiated Z-pinch experiments are numerically simulated using a two-dimensional resistive magnetohydrodynamic model, which includes many important experimental details, such as "cold-start" initial conditions, thermal conduction, radiative energy loss, actual discharge current vs. time, and grids of sufficient size and resolution to allow realistic development of the plasma. The alternating -direction-implicit numerical technique used meets the substantial demands presented by such a computational task. Simulations of fiber-initiated experiments show that when the fiber becomes fully ionized (at a time depending on current ramp and fiber thickness), rapidly developing m = 0 instabilities, which originated in the coronal plasma generated from the ablating fiber, drive intense non-uniform heating and rapid expansion of the plasma column. The possibility that inclusion of additional physical effects would improve stability is explored. Finite-Larmor-radius-ordered Hall and diamagnetic pressure terms in the magnetic field evolution equation, corresponding energy equation terms, and separate ion and electron energy equations are included; these do not change the basic results. Model diagnostics, such as shadowgrams and interferograms, generated from simulation results, are in good agreement with experiment. Two alternative experimental approaches are explored: high-current magnetic implosion of hollow cylindrical deuterium shells, and "plasma -on wire" (POW) implosion of low-density plasma onto a central deuterium fiber. By minimizing instability problems, these techniques may allow attainment of higher temperatures and densities than possible with bare fiber-initiated Z -pinches. Conditions for significant D-D or D-T fusion neutron production may be realizable with these implosion -based approaches.

  7. Depth selective diffuse optical computed topography: simulations and phantom experiments

    NASA Astrophysics Data System (ADS)

    Fujii, M.; Kawanaka, A.; Nakayama, K.

    2007-07-01

    Diffuse optical topography has excellent features as a noninvasive method that provides 2D location information of cortical activity. However, it cannot distinguish the activation depth. We propose an image reconstruction algorithm that suppresses undesirable effects of skin circulation. It comprises a filtering algorithm that extracts target signals from observation data contaminated by disturbing signals and a 2D visualizing process. Computer simulations revealed its excellent performance. We developed a depth selective diffuse optical topography system prototype and performed phantom experiments. Our algorithm significantly suppressed the influence of the disturbing body in the shallow plane with minimal degradation of the target signal.

  8. Event-based Simulation Model for Quantum Optics Experiments

    NASA Astrophysics Data System (ADS)

    De Raedt, H.; Michielsen, K.

    2011-03-01

    We present a corpuscular simulation model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory by generating detection events one-by-one. The event-based corpuscular model gives a unified description of multiple-beam fringes of a plane parallel plate and single-photon Mach-Zehnder interferometer, Wheeler's delayed choice, photon tunneling, quantum eraser, two-beam interference, double-slit, Einstein-Podolsky-Rosen-Bohm and Hanbury Brown-Twiss experiments. We also discuss the possibility to refute our corpuscular model.

  9. LMFBR source term experiments in the Fuel Aerosol Simulant Test (FAST) facility

    SciTech Connect

    Petrykowski, J.C.; Longest, A.W.

    1985-01-01

    The transport of uranium dioxide (UO/sub 2/) aerosol through liquid sodium was studied in a series of ten experiments in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory (ORNL). The experiments were designed to provide a mechanistic basis for evaluating the radiological source term associated with a postulated, energetic core disruptive accident (CDA) in a liquid metal fast breeder reactor (LMFBR). Aerosol was generated by capacitor discharge vaporization of UO/sub 2/ pellets which were submerged in a sodium pool under an argon cover gas. Measurements of the pool and cover gas pressures were used to study the transport of aerosol contained by vapor bubbles within the pool. Samples of cover gas were filtered to determine the quantity of aerosol released from the pool. The depth at which the aerosol was generated was found to be the most critical parameter affecting release. The largest release was observed in the baseline experiment where the sample was vaporized above the sodium pool. In the nine ''undersodium'' experiments aerosol was generated beneath the surface of the pool at depths varying from 30 to 1060 mm. The mass of aerosol released from the pool was found to be a very small fraction of the original specimen. It appears that the bulk of aerosol was contained by bubbles which collapsed within the pool. 18 refs., 11 figs., 4 tabs.

  10. Initial NIF Shock Timing Experiments: Comparison with Simulation

    NASA Astrophysics Data System (ADS)

    Robey, H. F.; Celliers, P. M.; Boehly, T. R.; Datte, P. S.; Bowers, M. W.; Olson, R. E.; Munro, D. H.; Milovich, J. L.; Jones, O. S.; Nikroo, A.; Kroll, J. J.; Horner, J. B.; Hamza, A. V.; Bhandarkar, S. D.; Giraldez, E.; Castro, C.; Gibson, C. R.; Eggert, J. H.; Smith, R. F.; Park, H.-S.; Young, B. K.; Hsing, W. W.; Landen, O. L.; Meyerhofer, D. D.

    2010-11-01

    Initial experiments are underway to demonstrate the techniques required to tune the shock timing of capsule implosions on the National Ignition Facility (NIF). These experiments use a modified cryogenic hohlraum geometry designed to precisely match the performance of ignition hohlraums. The targets employ a re-entrant Au cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shocks is diagnosed with VISAR (Velocity Interferometer System for Any Reflector) and DANTE. The results of these measurements will be used to set the precision pulse shape for ignition capsule implosions to follow. Experimental results and comparisons with numerical simulation are presented.

  11. Cryogenic Fracturing: Laboratory Visualization Experiments and Numerical Simulations Using Peridynamics

    NASA Astrophysics Data System (ADS)

    Martin-Short, R.; Edmiston, J. K.

    2015-12-01

    Typical hydraulic fracturing operations involve the use of a large quantity of water, which can be problematic for several reasons including possible formation (permeability) damage, disposal of waste water, and the use of precious local water resource. An alternate reservoir permeability enhancing technology not requiring water is cryogenic fracturing. This method induces controlled fracturing of rock formations by thermal shock and has potentially important applications in the geothermal and hydrocarbon industries. In this process, cryogenic fluid—such as liquid nitrogen—is injected into the subsurface, causing fracturing due to thermal gradients. These fractures may improve the formation permeability relative to that achievable by hydraulic fracturing alone. We conducted combined laboratory visualization and numerical simulations studies of thermal-shock-induced fracture initiation and propagation resulting from liquid nitrogen injection in rock and analog materials. The experiment used transparent soda-lime glass cubes to facilitate real-time visualization of fracture growth and the fracture network geometry. In this contribution, we report the effect of overall temperature difference between cryogenic fluid and solid material on the produced fracture network, by pre-heating the glass cubes to several temperatures and injecting liquid nitrogen. Temperatures are monitored at several points by thermocouple and the fracture evolution is captured visually by camera. The experiment was modeled using a customized, thermoelastic, fracture-capable numerical simulation code based on peridynamics. The performance of the numerical code was validated by the results of the laboratory experiments, and then the code was used to study the different factors affecting a cryogenic fracturing operation, including the evolution of residual stresses and constitutive relationships for material failure. In complex rock such as shale, understanding the process of cryogenic

  12. Simulation and analyses of the aeroassist flight experiment attitude update method

    NASA Technical Reports Server (NTRS)

    Carpenter, J. R.

    1991-01-01

    A method which will be used to update the alignment of the Aeroassist Flight Experiment's Inertial Measuring Unit is simulated and analyzed. This method, the Star Line Maneuver, uses measurements from the Space Shuttle Orbiter star trackers along with an extended Kalman filter to estimate a correction to the attitude quaternion maintained by an Inertial Measuring Unit in the Orbiter's payload bay. This quaternion is corrupted by on-orbit bending of the Orbiter payload bay with respect to the Orbiter navigation base, which is incorporated into the payload quaternion when it is initialized via a direct transfer of the Orbiter attitude state. The method of updating this quaternion is examined through verification of baseline cases and Monte Carlo analysis using a simplified simulation, The simulation uses nominal state dynamics and measurement models from the Kalman filter as its real world models, and is programmed on Microvax minicomputer using Matlab, and interactive matrix analysis tool. Results are presented which confirm and augment previous performance studies, thereby enhancing confidence in the Star Line Maneuver design methodology.

  13. Simulation and analyses of the aeroassist flight experiment attitude update method

    NASA Astrophysics Data System (ADS)

    Carpenter, J. R.

    1991-06-01

    A method which will be used to update the alignment of the Aeroassist Flight Experiment's Inertial Measuring Unit is simulated and analyzed. This method, the Star Line Maneuver, uses measurements from the Space Shuttle Orbiter star trackers along with an extended Kalman filter to estimate a correction to the attitude quaternion maintained by an Inertial Measuring Unit in the Orbiter's payload bay. This quaternion is corrupted by on-orbit bending of the Orbiter payload bay with respect to the Orbiter navigation base, which is incorporated into the payload quaternion when it is initialized via a direct transfer of the Orbiter attitude state. The method of updating this quaternion is examined through verification of baseline cases and Monte Carlo analysis using a simplified simulation, The simulation uses nominal state dynamics and measurement models from the Kalman filter as its real world models, and is programmed on Microvax minicomputer using Matlab, and interactive matrix analysis tool. Results are presented which confirm and augment previous performance studies, thereby enhancing confidence in the Star Line Maneuver design methodology.

  14. Simulation for Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Ye, Li; PRad Collaboration Collaboration

    2016-09-01

    The ``Proton Charge Radius Puzzle'' refers to 7 σ discrepancy between the proton charge radius extracted from muonic hydrogen Lamb shift measurements and that from the atomic hydrogen Lamb shift and e-p elastic scattering measurements. In order to get a better understanding of this puzzle, the PRad experiment (E12-11-106) was proposed and recently performed with 1.1 and 2.2 GeV unpolarized electron beam in Hall B at Jefferson Lab. The experiment aims to extract the electric form factor and the charge radius of proton by simultaneously measuring the e - p elastic scattering cross section and the Møller cross section at very low Q2(2 × 10-4 10-1(GeV / c) 2) region, with sub-percent precision. A windowless hydrogen gas flow target was used to better control the background. A high-efficiency and high-resolution calorimeter (HyCal) and a pair of Gas Electron Multiplier (GEM) chambers were used in the experiment. This talk will focus on comparing the detailed simulation of PRad experiment and its background with preliminary spectra from the data. This work is supported in part by NSF MRI Award PHY-1229153, the U.S. Department of Energy under Contacts No. DE-FG02-07ER41528, Thomas Jefferson National Laboratory, Mississippi State University and PRad collaboration.

  15. Rainfall simulation experiments with a small portable rainfall simulator: research on runoff generation and soil erosion

    NASA Astrophysics Data System (ADS)

    Iserloh, Thomas; Peter, Klaus Daniel; Fister, Wolfgang; Wirtz, Stefan; Butzen, Verena; Brings, Christine; Marzen, Miriam; Casper, Markus C.; Seeger, Manuel; Ries, Johannes B.

    2015-04-01

    The results of more than 500 rainfall simulations with a small portable rainfall simulator at various locations in West and North Africa and South and Central Europe will be presented. The analysis of this comprehensive database offers results concerning different research objectives: - erodibility of local soils regarding different vegetation cover, stone cover and land uses - runoff generation in gully catchments - process oriented experiments on the influence of sealing and crusting - trail erosion caused by goat- or sheep-trampling - recent erosion on geomorphological forms Runoff coefficients range from 0 to 100 % and eroded material from 0 to 500 g m^-2 during 30 min experiments with a rainfall intensity of 40 mm h^-1.

  16. Simulation of Force Spectroscopy Experiments on Galacturonic Acid Oligomers

    PubMed Central

    Cybulska, Justyna; Brzyska, Agnieszka; Zdunek, Artur; Woliński, Krzysztof

    2014-01-01

    Pectins, forming a matrix for cellulose and hemicellulose, determine the mechanics of plant cell walls. They undergo salient structural changes during their development. In the presence of divalent cations, usually calcium, pectins can form gel-like structures. Because of their importance they have been the subject of many force spectroscopy experiments, which have examined the conformational changes and molecular tensions due to external forces. The most abundant unit present in the pectin backbone is polygalacturonic acid. Unfortunately, experimental force spectroscopy on polygalacturonic acid molecules is still not a trivial task. The mechanism of the single-molecule response to external forces can be inferred by theoretical methods. Therefore, in this work we simulated such force spectroscopy experiments using the Enforced Geometry Optimization (EGO) method. We examined the oligomeric (up to hexamer) structures of α-D-galacturonic acid exposed to external stretching forces. The EGO simulation of the force spectroscopy appropriately reproduced the experimental course of the enforced conformational transition: chair →inverted chair via the twisted boat conformation(s) in the pyranose ring of α-D-galacturonic acid. Additionally, our theoretical approach also allowed to determine the minimum oligomer size adequate for the description of nano-mechanical properties of (poly)-α-D-galacturonic acid. PMID:25229407

  17. Integrated P1 Hohlraum/Capsule Simulations for NIF Experiments

    NASA Astrophysics Data System (ADS)

    Eder, David; Spears, Brian; Town, Richard; Jones, Oggie; Ma, Tammy; Pak, Arthur; Benedetti, Robin; Hatchett, Steve; Knauer, James; MacKinnon, Andrew; Yeamans, Charles; McNaney, James; Casey, Daniel

    2014-10-01

    We discuss integrated hohlraum/capsule post-shot simulations of two full-scale cryogenic NIF experiments that drove a DT symcap capsule downward/upward by having the peak power in the upper laser beams 16% greater/less than the lower beams. This laser asymmetry results in a radiation drive P1/P0 at the capsule ablation surface of ~2% and a downward/upward capsule velocity of order 100 microns/ns in agreement with the data. The experimental velocity is determined by comparing measurements at different locations of both the arrival times of DD and DT neutrons at time-of-flight detectors, and by zirconium activation measurements that are a function of neutron energy. We compare these two shots to a control shot for the same target with no specified laser asymmetries. We also discuss simulations of planned sub-scale warm symcap experiments that have a goal of measuring DT and DD ion temperatures and the electron temperature as a function of the imposed P1 to characterize the role of non-thermal velocity on temperature measurements. This work performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-656659.

  18. Simulation of microtearing turbulence in national spherical torus experiment

    SciTech Connect

    Guttenfelder, W.; Kaye, S. M.; Bell, R. E.; Hammett, G. W.; LeBlanc, B. P.; Mikkelsen, D. R.; Ren, Y.; Candy, J.; Nevins, W. M.; Wang, E.; Zhang, J.; Crocker, N. A.; Yuh, H.

    2012-05-15

    Thermal energy confinement times in National Spherical Torus Experiment (NSTX) dimensionless parameter scans increase with decreasing collisionality. While ion thermal transport is neoclassical, the source of anomalous electron thermal transport in these discharges remains unclear, leading to considerable uncertainty when extrapolating to future spherical tokamak (ST) devices at much lower collisionality. Linear gyrokinetic simulations find microtearing modes to be unstable in high collisionality discharges. First non-linear gyrokinetic simulations of microtearing turbulence in NSTX show they can yield experimental levels of transport. Magnetic flutter is responsible for almost all the transport ({approx}98%), perturbed field line trajectories are globally stochastic, and a test particle stochastic transport model agrees to within 25% of the simulated transport. Most significantly, microtearing transport is predicted to increase with electron collisionality, consistent with the observed NSTX confinement scaling. While this suggests microtearing modes may be the source of electron thermal transport, the predictions are also very sensitive to electron temperature gradient, indicating the scaling of the instability threshold is important. In addition, microtearing turbulence is susceptible to suppression via sheared E Multiplication-Sign B flows as experimental values of E Multiplication-Sign B shear (comparable to the linear growth rates) dramatically reduce the transport below experimental values. Refinements in numerical resolution and physics model assumptions are expected to minimize the apparent discrepancy. In cases where the predicted transport is strong, calculations suggest that a proposed polarimetry diagnostic may be sensitive to the magnetic perturbations associated with the unique structure of microtearing turbulence.

  19. A Little Vacation on Mars: Mars Simulation Microbial Challenge Experiments

    NASA Astrophysics Data System (ADS)

    Boston, P.; Todd, P.; Van De Camp, J.; Northup, D.; Spilde, M.

    2008-06-01

    Communities of microbial organisms isolated from a variety of extreme environments were subjected to 1 to 5 weeks of simulated Martian environmental conditions using the Mars Environment Simulation Chamber at the Techshot, Inc. facility in Greenville, Indiana. The goal of the overall experiment program was to assess survival of test Earth organisms under Mars full spectrum sunlight, low-latitude daily temperature profile and various Mars-atmosphere pressures (~50 mbar to 500 mbar, 100% CO2) and low moisture content. Organisms surviving after 5 weeks at 100 mbar included those from gypsum surface fracture communities in a Permian aged evaporite basin, desert varnish on andesite lavas around a manganese mine, and iron and manganese oxidizing organisms isolated from two caves in Mew Mexico. Phylogenetic DNA analysis revealed strains of cyanobacteria, bacterial genera (present in all surviving communities) Asticacaulis, Achromobacter, Comamonas, Pantoea, Verrucomicrobium, Bacillus, Gemmatimonas, Actinomyces, and others. At least one microcolonial fungal strain from a desert varnish community and at least one strain from Utah survived simulations. Strains related to the unusual cave bacterial group Bacteroidetes are present in survivor communities that resist isolation into pure culture implying that their consortial relationships may be critical to their survival.

  20. The LHCb Simulation Application, Gauss: Design, Evolution and Experience

    NASA Astrophysics Data System (ADS)

    Clemencic, M.; Corti, G.; Easo, S.; Jones, C. R.; Miglioranzi, S.; Pappagallo, M.; Robbe, P.; LHCb Collaboration

    2011-12-01

    The LHCb simulation application, Gauss, is based on the Gaudi framework and on experiment basic components such as the Event Model and Detector Description. Gauss also depends on external libraries for the generation of the primary events (PYTHIA 6, EvtGen, etc.) and on GEANT4 for particle transport in the experimental setup. The application supports the production of different types of events from minimum bias to B physics signals and particle guns. It is used for purely generator-level studies as well as full simulations. Gauss is used both directly by users and in massive central productions on the grid. The design and implementation of the application and its evolution due to evolving requirements will be described as in the case of the recently adopted Python-based configuration or the possibility of taking into account detectors conditions via a Simulation Conditions database. The challenge of supporting at the same time the flexibililty needed for the different tasks for which it is used, from evaluation of physics reach to background modeling, together with the stability and reliabilty of the code will also be described.

  1. Shocked materials at the intersection of experiment and simulation

    SciTech Connect

    Kadau, Kai

    2008-01-01

    Understanding the dynamic lattice response of solids under the extreme conditions of pressure, temperature and strain rate is a scientific quest that spans nearly a century. Critical to developing this understanding is the ability to probe and model the spatial and temporal evolution of the material microstructure and properties at the scale of the relevant physical phenomena -- nanometers to micrometers and picoseconds to nanoseconds. While experimental investigations over this range of spatial and temporal scales were unimaginable just a decade ago, new technologies and facilities currently under development and on the horizon have brought these goals within reach for the first time. The equivalent advancements in simulation capabilities now mean that we can conduct simulations and experiments at overlapping temporal and spatial scales. In this article, we describe some of our studies which exploit existing and new generation ultrabright, ultrafast x-ray sources and large scale molecular dynamics simulations to investigate the real-time physical phenomena that control the dynamic response of shocked materials.

  2. Shocked materials at the intersection of experiment and simulation

    SciTech Connect

    Lorenzana, H. E.; Belak, J. F.; Bradley, K. S.; Bringa, E. M.; Budil, K. S.; Cazamias, J. U.; El-Dasher, B.; Hawreliak, J. A.; Hessler, J.; Kadau, K.; Kalantar, D. H.; McNaney, J. M.; Milathianaki, D.; Rosolankova, K.; Swift, D. C.; Taravillo, M.; Van Buuren, T. W.; Wark, J. S.; de la Rubia, T. Diaz

    2008-04-01

    Understanding the dynamic lattice response of solids under the extreme conditions of pressure, temperature and strain rate is a scientific quest that spans nearly a century. Critical to developing this understanding is the ability to probe and model the spatial and temporal evolution of the material microstructure and properties at the scale of the relevant physical phenomena-nanometers to micrometers and picoseconds to nanoseconds. While experimental investigations over this range of spatial and temporal scales were unimaginable just a decade ago, new technologies and facilities currently under development and on the horizon have brought these goals within reach for the first time. The equivalent advancements in simulation capabilities now mean that we can conduct simulations and experiments at overlapping temporal and spatial scales. In this article, we describe some of our studies which exploit existing and new generation ultrabright, ultrafast x-ray sources and large scale molecular dynamics simulations to investigate the real-time physical phenomena that control the dynamic response of shocked materials.

  3. Simulation of nucleation in almost hard-sphere colloids: the discrepancy between experiment and simulation persists.

    PubMed

    Filion, L; Ni, R; Frenkel, D; Dijkstra, M

    2011-04-07

    In this paper we examine the phase behavior of the Weeks-Chandler-Andersen (WCA) potential with βε = 40. Crystal nucleation in this model system was recently studied by Kawasaki and Tanaka [Proc. Natl. Acad. Sci. U.S.A. 107, 14036 (2010)], who argued that the computed nucleation rates agree well with experiment, a finding that contradicted earlier simulation results. Here we report an extensive numerical study of crystallization in the WCA model, using three totally different techniques (Brownian dynamics, umbrella sampling, and forward flux sampling). We find that all simulations yield essentially the same nucleation rates. However, these rates differ significantly from the values reported by Kawasaki and Tanaka and hence we argue that the huge discrepancy in nucleation rates between simulation and experiment persists. When we map the WCA model onto a hard-sphere system, we find good agreement between the present simulation results and those that had been obtained for hard spheres [L. Filion, M. Hermes, R. Ni, and M. Dijkstra, J. Chem. Phys. 133, 244115 (2010); S. Auer and D. Frenkel, Nature 409, 1020 (2001)].

  4. The World Climate Exercise: Is (Simulated) Experience Our Best Teacher?

    NASA Astrophysics Data System (ADS)

    Rath, K.; Rooney-varga, J. N.; Jones, A.; Johnston, E.; Sterman, J.

    2015-12-01

    Meeting the challenge of climate change will clearly require 'deep learning' - learning that motivates a search for underlying meaning, a willingness to exert the sustained effort needed to understand complex problems, and innovative problem-solving. This type of learning is dependent on the level of the learner's engagement with the material, their intrinsic motivation to learn, intention to understand, and relevance of the material to the learner. Here, we present evidence for deep learning about climate change through a simulation-based role-playing exercise, World Climate. The exercise puts participants into the roles of delegates to the United Nations climate negotiations and asks them to create an international climate deal. They find out the implications of their decisions, according to the best available science, through the same decision-support computer simulation used to provide feedback for the real-world negotiations, C-ROADS. World Climate provides an opportunity for participants have an immersive, social experience in which they learn first-hand about both the social dynamics of climate change decision-making, through role-play, and the dynamics of the climate system, through an interactive computer simulation. Evaluation results so far have shown that the exercise is highly engaging and memorable and that it motivates large majorities of participants (>70%) to take action on climate change. In addition, we have found that it leads to substantial gains in understanding key systems thinking concepts (e.g., the stock-flow behavior of atmospheric CO2), as well as improvements in understanding of climate change causes and impacts. While research is still needed to better understand the impacts of simulation-based role-playing exercises like World Climate on behavior change, long-term understanding, transfer of systems thinking skills across topics, and the importance of social learning during the exercise, our results to date indicate that it is a

  5. Comparison of Electron Cloud Simulation and Experiments in the High-Current Experiment

    SciTech Connect

    Cohen, R H; Friedman, A; Covo, M K; Lund, S M; Molvik, A W; Bieniosek, F M; Seidl, P A; Vay, J; Stoltz, P; Veitzer, S

    2004-11-11

    Contaminating clouds of electrons are a common concern for accelerators of positive-charged particles, but there are some unique aspects of heavy-ion accelerators for fusion and high-energy density physics which make modeling such clouds especially challenging. In particular, self-consistent electron and ion simulation is required, including a particle advance scheme which can follow electrons in regions where electrons are strongly, weakly, and un-magnetized. We describe our approach to such self-consistency, and in particular a scheme for interpolating between full-orbit (Boris) and drift-kinetic particle pushes that enables electron time steps long compared to the typical gyro period in the magnets. We present tests and applications: simulation of electron clouds produced by three different kinds of sources indicates the sensitivity of the cloud shape to the nature of the source; first-of-a-kind self-consistent simulation of electron-cloud experiments on the High-Current Experiment (HCX) at LBNL, in which the machine can be flooded with electrons released by impact of the ion beam on an end plate, demonstrate the ability to reproduce key features of the ion-beam phase space; and simulation of a two-stream instability of thin beams in a magnetic field demonstrate the ability of the large-timestep mover to accurately calculate the instability.

  6. Testing the Impact of a Multi-year, Curriculum-based Undergraduate Research Experience (MY-CURE) in the Geosciences: Baseline Observations

    NASA Astrophysics Data System (ADS)

    Allen, J. L.; Creamer, E. G.; Kuehn, S. C.

    2016-12-01

    Short-term undergraduate research experiences (URE's) provide skill and confidence enhancement to students, but it is unclear how effective they are in comparison to a dedicated, longer-term URE. This study examines the impact of a long-term URE embedded in a sequence of five courses in the geology curriculum. It begins with a sophomore course in environmental geology, and continues through mineralogy, structural geology, and petrology, before concluding at our summer geology field camp. In this sequence, they build upon individual URE's related to the structure and petrology of fault rocks from a mid-crustal shear zone. Rather than have students engage in one or more short-term URE's, they retain the same project for two calendar years so that we can assess when and how different gains, including a more sophisticated understanding of the nature of science, begin to emerge and mature. As each student progresses, we document the longitudinal development of a diverse suite of gains including: (1) Technical and higher-order research skills, (2) personal gains such as self-identity as a scientist, and (3) communication skills. In this presentation, we describe the framework of the study and baseline observations recorded during the first year of a 2-year cohort. Using a Q-sort method, students were given a deck of 16 index cards with an educational outcome listed on each. They sorted the cards into three piles: Those that encouraged an interest in geology, those that deterred an interest, and those with no impact. Participants discussed the top cards from the negative and positive piles. The top attractors to geology are collegial relationships with faculty, the opportunity to use scientific equipment, field work, the concreteness of geology, and the availability of jobs. Factors that deter interest include hours of tedious homework, math courses, and time invested in wrong answers or failed experiments/sample preparation. Factors not yet evident include confidence in

  7. Neutron Transport Simulations for NIST Neutron Lifetime Experiment

    NASA Astrophysics Data System (ADS)

    Li, Fangchen; BL2 Collaboration Collaboration

    2016-09-01

    Neutrons in stable nuclei can exist forever; a free neutron lasts for about 15 minutes on average before it beta decays to a proton, an electron, and an antineutrino. Precision measurements of the neutron lifetime test the validity of weak interaction theory and provide input into the theory of the evolution of light elements in the early universe. There are two predominant ways of measuring the neutron lifetime: the bottle method and the beam method. The bottle method measures decays of ultracold neutrons that are stored in a bottle. The beam method measures decay protons in a beam of cold neutrons of known flux. An improved beam experiment is being prepared at the National Institute of Science and Technology (Gaithersburg, MD) with the goal of reducing statistical and systematic uncertainties to the level of 1 s. The purpose of my studies was to develop computer simulations of neutron transport to determine the beam collimation and study the neutron distribution's effect on systematic effects for the experiment, such as the solid angle of the neutron flux monitor. The motivation for the experiment and the results of this work will be presented. This work was supported, in part, by a Grant to Gettysburg College from the Howard Hughes Medical Institute through the Precollege and Undergraduate Science Education Program.

  8. Laboratory simulations of the pyrolytic release experiments - An interim report

    NASA Technical Reports Server (NTRS)

    Hubbard, J. S.

    1979-01-01

    During its operation on Mars the pyrolytic release experiment (PR) detected the fixation of small amounts of CO2 and/or CO. Laboratory simulations of the experimental conditions were made in an attempt to substantiate the previous conclusion that these reactions were chemical rather than biological. After pretreatment and incubation under various conditions, pyrolytic analysis was used to indicate the extent of surface catalyzed conversion of (C-14)O2 or (C-14)O to (C-14)-organic compounds. This abiotic synthesis was detected in experiments with three iron oxides, viz. hematite, magnetite and maghemite. When the incubation atmosphere was supplemented with water vapor, the levels of synthesis were in a range comparable to that detected in the Viking PR tests. An abiotic synthesis was also detected in experiments with a mixture of clays and minerals (Mars analog soil) or with montmorillonite artificially enriched in iron. With either substratum the reaction appeared to be the result of a photocatalytic synthesis of (C-14)-organics from (C-14)O and surface hydroxyl groups. This process was not dependent on the presence of water vapor in the incubation atmosphere. Although a duplication of the Viking data has not been achieved, these findings support the abiotic interpretation of the PR results.

  9. Simulations of Ion Coupling Experiments on NDCX-II relevant to IFE

    NASA Astrophysics Data System (ADS)

    Barnard, J. J.; More, R. M.; Terry, M.

    2012-10-01

    The Neutralized Drift Compression Experiment II (NDCX-II) is an induction accelerator for which the construction project was completed at Lawrence Berkeley National Laboratory in March, 2012, and is presently being commissioned. The baseline design for NDCX-II will accelerate ˜0.03 μC of singly charged lithium ions to 1.2 MeV (with possible upgrades up to 3.1 MeV), delivered in sub-ns pulses with sub-mm rms beam radii. The purpose of NDCX-II is to carry out beam and target interaction experiments relevant to IFE. We have carried out detailed hydrodynamic simulations of planar targets having several configurations. In this poster we will focus on experiments that maximize shock strength by traveling wave deposition (i.e. by varying ion beam energy in a velocity chirp) and/or by varying intensity profile, and we will also explore methods to optimize shock strengths in composite materials where shocks can be formed at material boundaries and at end-of-range. These results will be discussed in the context of heavy ion fusion direct drive targets.

  10. Nonadiabatic molecular dynamics simulations: synergies between theory and experiments.

    PubMed

    Tavernelli, Ivano

    2015-03-17

    Recent developments in nonadiabatic dynamics enabled ab inito simulations of complex ultrafast processes in the condensed phase. These advances have opened new avenues in the study of many photophysical and photochemical reactions triggered by the absorption of electromagnetic radiation. In particular, theoretical investigations can be combined with the most sophisticated femtosecond experimental techniques to guide the interpretation of measured time-resolved observables. At the same time, the availability of experimental data at high (spatial and time) resolution offers a unique opportunity for the benchmarking and the improvement of those theoretical models used to describe complex molecular systems in their natural environment. The established synergy between theory and experiments can produce a better understanding of new ultrafast physical and chemical processes at atomistic scale resolution. Furthermore, reliable ab inito molecular dynamics simulations can already be successfully employed as predictive tools to guide new experiments as well as the design of novel and better performing materials. In this paper, I will give a concise account on the state of the art of molecular dynamics simulations of complex molecular systems in their excited states. The principal aim of this approach is the description of a given system of interest under the most realistic ambient conditions including all environmental effects that influence experiments, for instance, the interaction with the solvent and with external time-dependent electric fields, temperature, and pressure. To this end, time-dependent density functional theory (TDDFT) is among the most efficient and accurate methods for the representation of the electronic dynamics, while trajectory surface hopping gives a valuable representation of the nuclear quantum dynamics in the excited states (including nonadiabatic effects). Concerning the environment and its effects on the dynamics, the quantum mechanics

  11. Simulation of Extreme Arctic Cyclones in IPCC AR5 Experiments

    NASA Astrophysics Data System (ADS)

    Vavrus, S. J.

    2012-12-01

    Although impending Arctic climate change is widely recognized, a wild card in its expression is how extreme weather events in this region will respond to greenhouse warming. Intense polar cyclones represent one type of high-latitude phenomena falling into this category, including very deep synoptic-scale cyclones and mesoscale polar lows. These systems inflict damage through high winds, heavy precipitation, and wave action along coastlines, and their impact is expected to expand in the future, when reduced sea ice cover allows enhanced wave energy. The loss of a buffering ice pack could greatly increase the rate of coastal erosion, which has already been increasing in the Arctic. These and related threats may amplify if extreme Arctic cyclones become more frequent and/or intense in a warming climate with much more open water to fuel them. This possibility has merit on the basis of GCM experiments, which project that greenhouse forcing causes lower mean sea level pressure (SLP) in the Arctic and a strengthening of the deepest storms over boreal high latitudes. In this study, the latest Coupled Model Intercomparison Project (CMIP5) climate model output is used to investigate the following questions: (1) What are the spatial and seasonal characteristics of extreme Arctic cyclones? (2) How well do GCMs simulate these phenomena? (3) Are Arctic cyclones already showing the expected response to greenhouse warming in climate models? To address these questions, a retrospective analysis is conducted of the transient 20th century simulations among the CMIP5 GCMs (spanning years 1850-2005). The results demonstrate that GCMs are able to reasonably represent extreme Arctic cyclones and that the simulated characteristics do not depend significantly on model resolution. Consistent with observational evidence, climate models generate these storms primarily during winter and within the climatological Aleutian and Icelandic Low regions. Occasionally the cyclones remain very intense

  12. Impact of fecal immunochemical test-based screening programs on proximal and distal colorectal cancer surgery rates: A natural multiple-baseline experiment.

    PubMed

    Fedeli, Ugo; Zorzi, Manuel; Urso, Emanuele D L; Gennaro, Nicola; Dei Tos, Angelo P; Saugo, Mario

    2015-11-15

    Colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) were found to reduce overall CRC surgery rates, but to the authors' knowledge data by subsite are lacking. The objective of the current study was to assess the impact of FIT-based screening on proximal and distal CRC surgical resection rates. The Veneto region in Italy can be subdivided into 3 areas with staggered introduction of FIT-based screening programs: early (2002-2004), intermediate (2005-2007), and late (2008-2009) areas. Time series of proximal and distal CRC surgery were investigated in the 3 populations between 2001 and 2012 by Joinpoint regression analysis and segmented Poisson regression models. The impact of screening was similar in the study populations. Rates of distal CRC surgical resection were stable before screening, increased at the time of screening implementation (rate ratio [RR], 1.25; 95% confidence interval [95% CI], 1.14-1.37), and thereafter declined by 10% annually (RR, 0.90; 95% CI, 0.88-0.92). Rates of proximal CRC surgical resection increased by 4% annually before screening (RR, 1.04; 95% CI, 1.03-1.05) but, after a peak at the time of screening initiation, the trend was reversed. The percentage represented by proximal CRC surgery rose from 28% in 2001 to 41% in 2012. In this natural multiple-baseline experiment, consistent findings across each time series demonstrated that FIT-based screening programs have an impact both on proximal and distal CRC surgery rates. However, underlying preexisting epidemiological trends are leading to a rapidly increasing percentage of proximal CRC. © 2015 American Cancer Society.

  13. A natural experiment opportunity in two low-income urban food desert communities: research design, community engagement methods, and baseline results.

    PubMed

    Dubowitz, Tamara; Ncube, Collette; Leuschner, Kristin; Tharp-Gilliam, Shannah

    2015-04-01

    A growing body of evidence has highlighted an association between a lack of access to nutritious, affordable food (e.g., through full-service grocery stores [FSGs]), poor diet, and increased risk for obesity. In response, there has been growing interest among policy makers in encouraging the siting of supermarkets in "food deserts," that is, low-income geographic areas with low access to healthy food options. However, there is limited research to evaluate the impact of such efforts, and most studies to date have been cross-sectional. The Pittsburgh Hill/Homewood Research on Eating, Shopping, and Health (PHRESH) is a longitudinal quasi-experimental study of a dramatic change (i.e., a new FSG) in the food landscape of a low-income, predominantly Black neighborhood. The study is following a stratified random sample of households (n = 1,372), and all food venues (n = 60) in both intervention and control neighborhoods, and the most frequently reported food shopping venues outside both neighborhoods. This article describes the study design and community-based methodology, which focused simultaneously on the conduct of scientifically rigorous research and the development and maintenance of trust and buy-in from the involved neighborhoods. Early results have begun to define markers for success in creating a natural experiment, including strong community engagement. Baseline data show that the vast majority of residents already shop at a FSG and do not shop at the nearest one. Follow-up data collection will help determine whether and how a new FSG may change behaviors and may point to the need for additional interventions beyond new FSGs alone. © 2015 Society for Public Health Education.

  14. A facility for long-term Mars simulation experiments: the Mars Environmental Simulation Chamber (MESCH).

    PubMed

    Jensen, Lars Liengaard; Merrison, Jonathan; Hansen, Aviaja Anna; Mikkelsen, Karina Aarup; Kristoffersen, Tommy; Nørnberg, Per; Lomstein, Bente Aagaard; Finster, Kai

    2008-06-01

    We describe the design, construction, and pilot operation of a Mars simulation facility comprised of a cryogenic environmental chamber, an atmospheric gas analyzer, and a xenon/mercury discharge source for UV generation. The Mars Environmental Simulation Chamber (MESCH) consists of a double-walled cylindrical chamber. The double wall provides a cooling mantle through which liquid N(2) can be circulated. A load-lock system that consists of a small pressure-exchange chamber, which can be evacuated, allows for the exchange of samples without changing the chamber environment. Fitted within the MESCH is a carousel, which holds up to 10 steel sample tubes. Rotation of the carousel is controlled by an external motor. Each sample in the carousel can be placed at any desired position. Environmental data, such as temperature, pressure, and UV exposure time, are computer logged and used in automated feedback mechanisms, enabling a wide variety of experiments that include time series. Tests of the simulation facility have successfully demonstrated its ability to produce temperature cycles and maintain low temperature (down to -140 degrees C), low atmospheric pressure (5-10 mbar), and a gas composition like that of Mars during long-term experiments.

  15. Freak waves in a tank experiments and simulations

    NASA Astrophysics Data System (ADS)

    Kit, E.; Shemer, L.

    2003-04-01

    Understanding of freak waves requires an inter-related experimental and theoretical effort. Recently, a 1D linear theory was suggested that attributes the generation of freak waves to spatial and temporal focusing (Pelinovsky &Kharif, 2000). However, experiments of Brown &Jensen (2001) demonstrated that nonlinear effects are essential in the evolution of those waves. Kharif et al. (2001) applied cubic Schrödinger equation (CSE) to simulate nonlinear freak waves. To overcome the narrow-band restriction of the CSE, two interrelated models are used here: the spatial version of the Zakharov equation, and the closely related spatial model in the physical space due to Dysthe (Kit &Shemer 2002). We carry out combined experimental and numerical study of freak waves. The numerical computations assume that a narrow and steep wave group is supposed to be observed at a prescribed distance from the wavemaker. This group envelope and the corresponding spectrum are then integrated backwards up to the wavemaker using the two models. The resulting waveforms are used to drive the wavemaker. The study is carried for a number of values of the maximum wave steepness. In the Zakharov equation computations 70 Fourier modes are used. As expected, steep wave indeed emerged at the prescribed location. Both experiments and the numerical simulations demonstrate that the amplitude spectra of the wave field vary considerably along the tank, stressing the importance of nonlinearity. Quantitative comparison is carried out between the experiments and the model computations using both spatial models. References Brown, M.G., and Jensen, A. 2001 Experiments on focusing unidirectional water waves. J. Geophys. Res. 106, 16,917-16,928. Kharif, C., Pelinovsky, E., Talipova, T., and Slunyaev, A. 2001 Focusing of nonlinear wave groups in deep water. JETP Letters 73, 170-175. Kit, E., and Shemer, L. 2002 Spatial versions of the Zakharov and Dysthe evolution equations for deep water gravity waves. J. Fluid

  16. Color film spectral properties test experiment for target simulation

    NASA Astrophysics Data System (ADS)

    Liu, Xinyue; Ming, Xing; Fan, Da; Guo, Wenji

    2017-04-01

    In hardware-in-loop test of the aviation spectra camera, the liquid crystal light valve and digital micro-mirror device could not simulate the spectrum characteristics of the landmark. A test system frame was provided based on the color film for testing the spectra camera; and the spectrum characteristics of the color film was test in the paper. The result of the experiment shows that difference was existed between the landmark and the film spectrum curse. However, the spectrum curse peak should change according to the color, and the curse is similar with the standard color traps. So, if the quantity value of error between the landmark and the film was calibrated and the error could be compensated, the film could be utilized in the hardware-in-loop test for the aviation spectra camera.

  17. Movement of patches during thermoforming: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Schell, J. S. U.; Amory, L.; Guillon, D.

    2016-10-01

    The application of local reinforcement like uni-directional patches can locally increase the strength of composite parts without adding much weight. During design through structural analysis, shape and position of local reinforcement can easily be determined. In the thermoforming process, patches can be integrated into the ply-stack by preassembling. During forming, these patches can move and change their position reducing the structural effect of the patch. The movement of patches has been investigated experimentally. Key factors that influence this movement are orientation, size, position in the pile and slope of the mold. The forming process is simulated using HYPERFORM. The results show that this complex process needs special models which can be computationally intensive. In this work, we model the movement of patches and compare with experiments. The final goal is to have a reasonable predictive capability for movement of patches and design the process to minimize it.

  18. Simulation of the photogrammetric appendage structural dynamics experiment

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Gilbert, Michael G.; Welch, Sharon S.

    1995-01-01

    The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) uses six video cameras in the Space Shuttle cargo bay to measure vibration of the Russian Mir space station Kvant-ll solar array. It occurs on Shuttle/Mir docking mission STS-74 scheduled for launch in November 1995. The objective of PASDE is to demonstrate photogrammetric technology for measuring 'untargeted' spacecraft appendage structural dynamics. This paper discusses a pre-flight simulation test conducted in July 1995, focusing on the image processing aspects. The flight camera system recorded vibrations of a full-scale structural test article having grids of white lines on black background, similar in appearance to the Mir solar array. Using image correlation analysis, line intersections on the structure are tracked in the video recordings to resolutions of less than 0.1 pixel. Calibration and merging of multiple camera views generated 3-dimensional displacements from which structural modal parameters are then obtained.

  19. First experience of vectorizing electromagnetic physics models for detector simulation

    NASA Astrophysics Data System (ADS)

    Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Bianchini, C.; Bitzes, G.; Brun, R.; Canal, P.; Carminati, F.; de Fine Licht, J.; Duhem, L.; Elvira, D.; Gheata, A.; Jun, S. Y.; Lima, G.; Novak, M.; Presbyterian, M.; Shadura, O.; Seghal, R.; Wenzel, S.

    2015-12-01

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. The GeantV vector prototype for detector simulations has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth, parallelization needed to achieve optimal performance or memory access latency and speed. An additional challenge is to avoid the code duplication often inherent to supporting heterogeneous platforms. In this paper we present the first experience of vectorizing electromagnetic physics models developed for the GeantV project.

  20. An Atmospheric Science Observing System Simulation Experiment (OSSE) Environment

    NASA Technical Reports Server (NTRS)

    Lee, Meemong; Weidner, Richard; Qu, Zheng; Bowman, Kevin; Eldering, Annmarie

    2010-01-01

    An atmospheric sounding mission starts with a wide range of concept designs involving measurement technologies, observing platforms, and observation scenarios. Observing system simulation experiment (OSSE) is a technical approach to evaluate the relative merits of mission and instrument concepts. At Jet Propulsion Laboratory (JPL), the OSSE team has developed an OSSE environment that allows atmospheric scientists to systematically explore a wide range of mission and instrument concepts and formulate a science traceability matrix with a quantitative science impact analysis. The OSSE environment virtually creates a multi-platform atmospheric sounding testbed (MAST) by integrating atmospheric phenomena models, forward modeling methods, and inverse modeling methods. The MAST performs OSSEs in four loosely coupled processes, observation scenario exploration, measurement quality exploration, measurement quality evaluation, and science impact analysis.

  1. First experience of vectorizing electromagnetic physics models for detector simulation

    SciTech Connect

    Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Bianchini, C.; Bitzes, G.; Brun, R.; Canal, P.; Carminati, F.; Licht, J.de Fine; Duhem, L.; Elvira, D.; Gheata, A.; Jun, S. Y.; Lima, G.; Novak, M.; Presbyterian, M.; Shadura, O.; Seghal, R.; Wenzel, S.

    2015-12-23

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. The GeantV vector prototype for detector simulations has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth, parallelization needed to achieve optimal performance or memory access latency and speed. An additional challenge is to avoid the code duplication often inherent to supporting heterogeneous platforms. In this paper we present the first experience of vectorizing electromagnetic physics models developed for the GeantV project.

  2. Experiences using DAKOTA stochastic expansion methods in computational simulations.

    SciTech Connect

    Templeton, Jeremy Alan; Ruthruff, Joseph R.

    2012-01-01

    Uncertainty quantification (UQ) methods bring rigorous statistical connections to the analysis of computational and experiment data, and provide a basis for probabilistically assessing margins associated with safety and reliability. The DAKOTA toolkit developed at Sandia National Laboratories implements a number of UQ methods, which are being increasingly adopted by modeling and simulation teams to facilitate these analyses. This report disseminates results as to the performance of DAKOTA's stochastic expansion methods for UQ on a representative application. Our results provide a number of insights that may be of interest to future users of these methods, including the behavior of the methods in estimating responses at varying probability levels, and the expansion levels for the methodologies that may be needed to achieve convergence.

  3. Krypton Production Cross Sections and Production Rates in Simulation Experiments

    NASA Astrophysics Data System (ADS)

    Gilabert, E.; Lavielle, B.; Schiekel, Th.; Herpers, U.; Neumann, S.; Michel, R.

    1995-09-01

    The stacked-foil technique was used to measured proton induced excitation functions from Sr targets (SrF2). The irradiations were performed at the Laboratoire National Saturne in Saclay (F), the Svedberg Laboratory in Uppsala (S) and the Paul Scherrer Institute in Villigen (CH) with primary energies from 45 to 400 MeV. After gamma-spectrometric measurement of short and medium-lived radionuclides and after sufficient cooling, stable and long lived Kr isotopes were measured at Centre Etude Nucleaire in Bordeaux (F). Deduced cross sections were corrected for the production of secondary protons and neutrons by a method developed by Lupke[1]. There are no literature data which can be compared with the cross sections from this work. Theoretical calculations of cross sections were performed using two approaches. The first one was using the hybrid model of preequilibrium reactions with the code AREL[2]. The second was using the Intra-Nuclear-Cascade/Evaporation model in the form of the High Energy Transport Code (HETC)[3]. This study shows that for energies above 200 MeV, the spallation model is better suited to explain the nuclear reactions whereas the preequilibrium model leads to underestimation of the experimental data. For energies above 200 MeV, HETC should be preferred to AREL calculations. In physical models describing galactic cosmic ray (GCR) interactions with matter [4], cross sections of both, proton and neutron-induced reactions, are important parameters. Using the measured cross sections for proton-induced reactions from this work and the experimental Kr depth profiles obtained from Sr targets in the LNS172 simulation experiment [5], we established a set of excitation functions for neutron-induced reactions, which now excellently describes the production rate depth profiles from the simulation experiment. Before measuring experimental cross sections for Kr from Sr, the theoretical depth profiles calculated with pure theoretical excitation functions showed

  4. Aerodynamics of ski jumping: experiments and CFD simulations

    NASA Astrophysics Data System (ADS)

    Meile, W.; Reisenberger, E.; Mayer, M.; Schmölzer, B.; Müller, W.; Brenn, G.

    2006-12-01

    The aerodynamic behaviour of a model ski jumper is investigated experimentally at full-scale Reynolds numbers and computationally applying a standard RANS code. In particular we focus on the influence of different postures on aerodynamic forces in a wide range of angles of attack. The experimental results proved to be in good agreement with full-scale measurements with athletes in much larger wind tunnels, and form a reliable basis for further predictions of the effects of position changes on the performance. The comparison of CFD results with the experiments shows poor agreement, but enables a clear outline of simulation potentials and limits when accurate predictions of effects from small variations are required.

  5. Experiment and simulation on one-dimensional plasma photonic crystals

    SciTech Connect

    Zhang, Lin; Ouyang, Ji-Ting

    2014-10-15

    The transmission characteristics of microwaves passing through one-dimensional plasma photonic crystals (PPCs) have been investigated by experiment and simulation. The PPCs were formed by a series of discharge tubes filled with argon at 5 Torr that the plasma density in tubes can be varied by adjusting the discharge current. The transmittance of X-band microwaves through the crystal structure was measured under different discharge currents and geometrical parameters. The finite-different time-domain method was employed to analyze the detailed properties of the microwaves propagation. The results show that there exist bandgaps when the plasma is turned on. The properties of bandgaps depend on the plasma density and the geometrical parameters of the PPCs structure. The PPCs can perform as dynamical band-stop filter to control the transmission of microwaves within a wide frequency range.

  6. Hybrid Reynolds-Averaged/Large-Eddy Simulations of a Co-Axial Supersonic Free-Jet Experiment

    NASA Technical Reports Server (NTRS)

    Baurle, R. A.; Edwards, J. R.

    2009-01-01

    Reynolds-averaged and hybrid Reynolds-averaged/large-eddy simulations have been applied to a supersonic coaxial jet flow experiment. The experiment utilized either helium or argon as the inner jet nozzle fluid, and the outer jet nozzle fluid consisted of laboratory air. The inner and outer nozzles were designed and operated to produce nearly pressure-matched Mach 1.8 flow conditions at the jet exit. The purpose of the computational effort was to assess the state-of-the-art for each modeling approach, and to use the hybrid Reynolds-averaged/large-eddy simulations to gather insight into the deficiencies of the Reynolds-averaged closure models. The Reynolds-averaged simulations displayed a strong sensitivity to choice of turbulent Schmidt number. The baseline value chosen for this parameter resulted in an over-prediction of the mixing layer spreading rate for the helium case, but the opposite trend was noted when argon was used as the injectant. A larger turbulent Schmidt number greatly improved the comparison of the results with measurements for the helium simulations, but variations in the Schmidt number did not improve the argon comparisons. The hybrid simulation results showed the same trends as the baseline Reynolds-averaged predictions. The primary reason conjectured for the discrepancy between the hybrid simulation results and the measurements centered around issues related to the transition from a Reynolds-averaged state to one with resolved turbulent content. Improvements to the inflow conditions are suggested as a remedy to this dilemma. Comparisons between resolved second-order turbulence statistics and their modeled Reynolds-averaged counterparts were also performed.

  7. Combining experiments and simulations using the maximum entropy principle.

    PubMed

    Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

    2014-02-01

    A key component of computational biology is to compare the results of computer modelling with experimental measurements. Despite substantial progress in the models and algorithms used in many areas of computational biology, such comparisons sometimes reveal that the computations are not in quantitative agreement with experimental data. The principle of maximum entropy is a general procedure for constructing probability distributions in the light of new data, making it a natural tool in cases when an initial model provides results that are at odds with experiments. The number of maximum entropy applications in our field has grown steadily in recent years, in areas as diverse as sequence analysis, structural modelling, and neurobiology. In this Perspectives article, we give a broad introduction to the method, in an attempt to encourage its further adoption. The general procedure is explained in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results that are at not in complete and quantitative accordance with experiments. A common solution to this problem is to explicitly ensure agreement between the two by perturbing the potential energy function towards the experimental data. So far, a general consensus for how such perturbations should be implemented has been lacking. Three very recent papers have explored this problem using the maximum entropy approach, providing both new theoretical and practical insights to the problem. We highlight each of these contributions in turn and conclude with a discussion on remaining challenges.

  8. Simulations of MATROSHKA experiments at ISS using PHITS

    NASA Astrophysics Data System (ADS)

    Puchalska, Monika; Sihver, L.; Sato, T.; Berger, T.; Reitz, G.

    Concerns about the biological effects of space radiation are increasing rapidly due to the per-spective of long-duration manned missions, both in relation to the International Space Station (ISS) and to manned interplanetary missions to Moon and Mars in the future. As a prepara-tion for these long duration space missions it is important to ensure an excellent capability to evaluate the impact of space radiation on human health in order to secure the safety of the astronauts/cosmonauts and minimize their risks. It is therefore necessary to measure the radi-ation load on the personnel both inside and outside the space vehicles and certify that organ and tissue equivalent doses can be simulated as accurate as possible. In this paper we will present simulations using the three-dimensional Monte Carlo Particle and Heavy Ion Transport code System (PHITS) of long term dose measurements performed with the ESA supported ex-periment MATROSHKA (MTR), which is an anthropomorphic phantom containing over 6000 radiation detectors, mimicking a human head and torso. The MTR experiment, led by the German Aerospace Center (DLR), was launched in January 2004 and has measured the ab-sorbed dose from space radiation both inside and outside the ISS. In this paper preliminary comparisons of measured and calculated dose and organ doses in the MTR located outside the ISS will be presented. The results confirm previous calculations and measurements which indicate that PHITS is a suitable tool for estimations of dose received from cosmic radiation and when performing shielding design studies of spacecraft. Acknowledgement: The research leading to these results has received funding from the Euro-pean Commission in the frame of the FP7 HAMLET project (Project 218817).

  9. Simulations of background sources in AMoRE-I experiment

    NASA Astrophysics Data System (ADS)

    Luqman, A.; Ha, D. H.; Lee, J. J.; Jeon, E. J.; Jo, H. S.; Kim, H. J.; Kim, Y. D.; Kim, Y. H.; Kobychev, V. V.; Lee, H. S.; Park, H. K.; Siyeon, K.; So, J. H.; Tretyak, V. I.; Yoon, Y. S.

    2017-05-01

    The first phase of the Advanced Mo-based Rare process Experiment (AMoRE-I), an experimental search for neutrinoless double beta decay (0 νββ) of 100Mo in calcium molybdate (40Ca100MoO4) crystal using cryogenic detection techniques, is in preparation at the YangYang underground laboratory (Y2L) in Korea. A GEANT4 based Monte Carlo simulation was performed for the first-phase AMoRE detector and shield configuration. Background sources such as 238U, 232Th, 235U, and 210Pb from inside the crystals, surrounding materials, outer shielding walls of the Y2L cavity were simulated. The estimated background rate in the region of interest was estimated to be < 1.5 ×10-3 counts/keV/kg/yr (ckky). The effects of random coincidences between backgrounds and two-neutrino double beta decays of 100Mo as a potential background source were estimated to be < 2.3 ×10-4 ckky.

  10. A horizontal vane radiometer: Experiment, theory, and simulation

    SciTech Connect

    Wolfe, David; Larraza, Andres; Garcia, Alejandro

    2016-03-15

    The existence of two motive forces on a Crookes radiometer has complicated the investigation of either force independently. The thermal creep shear force in particular has been subject to differing interpretations of the direction in which it acts and its order of magnitude. In this article, we provide a horizontal vane radiometer design which isolates the thermal creep shear force. The horizontal vane radiometer is explored through experiment, kinetic theory, and the Direct Simulation Monte Carlo (DSMC) method. The qualitative agreement between the three methods of investigation is good except for a dependence of the force on the width of the vane even when the temperature gradient is narrower than the vane which is present in the DSMC method results but not in the theory. The experimental results qualitatively resemble the theory in this regard. The quantitative agreement between the three methods of investigation is better than an order of magnitude in the cases examined. The theory is closer to the experimental values for narrow vanes and the simulations are closer to the experimental values for the wide vanes. We find that the thermal creep force acts from the hot side to the cold side of the vane. We also find the peak in the radiometer’s angular speed as a function of pressure is explained as much by the behavior of the drag force as by the behavior of the thermal creep force.

  11. Fundamental investigations of capacitive radio frequency plasmas: simulations and experiments

    NASA Astrophysics Data System (ADS)

    Donkó, Z.; Schulze, J.; Czarnetzki, U.; Derzsi, A.; Hartmann, P.; Korolov, I.; Schüngel, E.

    2012-12-01

    Capacitive radio frequency (RF) discharge plasmas have been serving hi-tech industry (e.g. chip and solar cell manufacturing, realization of biocompatible surfaces) for several years. Nonetheless, their complex modes of operation are not fully understood and represent topics of high interest. The understanding of these phenomena is aided by modern diagnostic techniques and computer simulations. From the industrial point of view the control of ion properties is of particular interest; possibilities of independent control of the ion flux and the ion energy have been utilized via excitation of the discharges with multiple frequencies. ‘Classical’ dual-frequency (DF) discharges (where two significantly different driving frequencies are used), as well as discharges driven by a base frequency and its higher harmonic(s) have been analyzed thoroughly. It has been recognized that the second solution results in an electrically induced asymmetry (electrical asymmetry effect), which provides the basis for the control of the mean ion energy. This paper reviews recent advances on studies of the different electron heating mechanisms, on the possibilities of the separate control of ion energy and ion flux in DF discharges, on the effects of secondary electrons, as well as on the non-linear behavior (self-generated resonant current oscillations) of capacitive RF plasmas. The work is based on a synergistic approach of theoretical modeling, experiments and kinetic simulations based on the particle-in-cell approach.

  12. Parallel collisionless shocks forming in simulations of the LAPD experiment

    NASA Astrophysics Data System (ADS)

    Weidl, Martin S.; Jenko, Frank; Niemann, Chris; Winske, Dan

    2016-10-01

    Research on parallel collisionless shocks, most prominently occurring in the Earth's bow shock region, has so far been limited to satellite measurements and simulations. However, the formation of collisionless shocks depends on a wide range of parameters and scales, which can be accessed more easily in a laboratory experiment. Using a kJ-class laser, an ongoing experimental campaign at the Large Plasma Device (LAPD) at UCLA is expected to produce the first laboratory measurements of the formation of a parallel collisionless shock. We present hybrid kinetic/MHD simulations that show how beam instabilities in the background plasma can be driven by ablating carbon ions from a target, causing non-linear density oscillations which develop into a propagating shock front. The free-streaming carbon ions can excite both the resonant right-hand instability and the non-resonant firehose mode. We analyze their respective roles and discuss optimizing their growth rates to speed up the process of shock formation.

  13. Theory and Simulation of an Inverse Free Electron Laser Experiment

    NASA Astrophysics Data System (ADS)

    Guo, S. K.; Bhattacharjee, A.; Fang, J. M.; Marshall, T. C.

    1996-11-01

    An experimental demonstration of the acceleration of electrons using a high power CO2 laser in an inverse free electron laser (IFEL) is underway at the Brookhaven National Laboratory. This experiment has generated data, which we are attempting to simulate. Included in our studies are such effects as: a low-loss metallic waveguide with a dielectric coating on the walls; multi-mode coupling due to self-consistent interaction between the electrons and the optical wave; space charge (which is significant at lower laser power); energy-spread of the electrons; arbitrary wiggler field profile; and slippage. Two types of wiggler profile have been considered: a linear taper of the period, and a step-taper of the period (the period is ~ 3cm, the field is ~ 1T, and the wiggler length is 47cm). The energy increment of the electrons ( ~ 1-2%) is analyzed in detail as a function of laser power, wiggler parameters, and the initial beam energy (40MeV). For laser power ~ 0.5GW, the predictions of the simulations are in good accord with experimental results. A matter currently under study is the discrepancy between theory and observations for the electron energy distribution observed at the end of the IFEL. This work is supported by the Department of Energy.

  14. Visualizing simulated learning experiences through the use of informatics tools.

    PubMed

    Thompson, Teri L; Warren, Judith J

    2009-01-01

    High-fidelity simulation technology is a growing educational technology. Designing effective simulations requires the use of informatics tools such as UML modeling. This poster demonstrates the steps in modeling a simulation exercise.

  15. Numerical Simulation of Receptivity for a Transition Experiment

    NASA Technical Reports Server (NTRS)

    Collis, S. Scott; Joslin, R. D. (Technical Monitor)

    2000-01-01

    The cost of fuel to overcome turbulence induced viscous drag on a commercial airplane constitutes a significant fraction of the operating cost of an airline. Achieving laminar flow and maintaining it over a large portion of the wing can significantly reduce the viscous drag, and hence the cost. Design of such laminar-flow-control wings and their practical operation requires the ability to accurately and reliably predict the transition from laminar to turbulent flow. The transition process begins with the conversion of environmental and surface disturbances into the instability waves of the flow by a process called receptivity. The goal of the current research project has been to improve the prediction of transition through a better understanding of the physics of receptivity. The initial objective of this work was to investigate the specific stability and receptivity characteristics of a particular experimental investigation of boundary layer receptivity at NASA Langley. Some simulation results using direct solutions of the linearized Navier-Stokes equations which modeled this experiment where presented in the 1999 APS DFD meeting. However, based on these initial investigations, it became clear that to cover the vast receptivity parameter space required for a practical transition prediction tool, more efficient methods would be required. Thus, the focus of this research was shifted from modeling this particular experiment to formulating and developing new techniques that could efficiently yet accurately predict receptivity for a wide range of disturbance conditions.

  16. Phase Transitions in Simulation of Hypervelocity Impact Experiments

    NASA Astrophysics Data System (ADS)

    Povarnitsyn, Mikhail; Zakharenkov, Alexey; Khishchenko, Konstantin; Levashov, Pavel

    2009-06-01

    Hypervelocity impact experiments can give us additional information about thermodynamical properties of matter in extreme state. In this work we simulate shock--induced melting, fragmentation and vaporization in aluminum and zinc targets. A tantalum impactor strikes zinc and aluminum targets at a velocity of 10 km/s and causes melting of these materials in a shock wave. Then under intensive rarefaction the thermodynamic path crosses the liquid--vapor coexistence boundary and enters into a metastable liquid state. Liquid in a metastable state undergoes either liquid--vapor phase separation or mechanical spallation. The theory of homogeneous nucleation as well as mechanical fragmentation criterion are used to control the kinetics of these processes in our model. The first effect dominates in the vicinity of the critical point, the second one at lower temperatures and negative pressure. Phase transitions and kinetics of phase separations are taken into account using a thermodynamically complete equation of state in tabular form with stable and metastable states for all materials under consideration. It is shown that liquid--vapor properties are very important for adequate description of experiment.

  17. Microwave window breakdown experiments and simulations on the UM/L-3 relativistic magnetron.

    PubMed

    Hoff, B W; Mardahl, P J; Gilgenbach, R M; Haworth, M D; French, D M; Lau, Y Y; Franzi, M

    2009-09-01

    Experiments have been performed on the UM/L-3 (6-vane, L-band) relativistic magnetron to test a new microwave window configuration designed to limit vacuum side breakdown. In the baseline case, acrylic microwave windows were mounted between three of the waveguide coupling cavities in the anode block vacuum housing and the output waveguides. Each of the six 3 cm deep coupling cavities is separated from its corresponding anode cavity by a 1.75 cm wide aperture. In the baseline case, vacuum side window breakdown was observed to initiate at single waveguide output powers close to 20 MW. In the new window configuration, three Air Force Research Laboratory-designed, vacuum-rated directional coupler waveguide segments were mounted between the coupling cavities and the microwave windows. The inclusion of the vacuum side power couplers moved the microwave windows an additional 30 cm away from the anode apertures. Additionally, the Lucite microwave windows were replaced with polycarbonate windows and the microwave window mounts were redesigned to better maintain waveguide continuity in the region around the microwave windows. No vacuum side window breakdown was observed in the new window configuration at single waveguide output powers of 120+MW (a factor of 3 increase in measured microwave pulse duration and factor of 3 increase in measured peak power over the baseline case). Simulations were performed to investigate likely causes for the window breakdown in the original configuration. Results from these simulations have shown that in the original configuration, at typical operating voltage and magnetic field ranges, electrons emitted from the anode block microwave apertures strike the windows with a mean kinetic energy of 33 keV with a standard deviation of 14 keV. Calculations performed using electron impact angle and energy data predict a first generation secondary electron yield of 65% of the primary electron population. The effects of the primary aperture electron

  18. Cardiovascular model for the simulation of exercise, lower body negative pressure, and tilt experiments

    NASA Technical Reports Server (NTRS)

    Croston, R. C.; Fitzjerrell, D. G.

    1974-01-01

    A mathematical model and digital computer simulation of the human cardiovascular system and its controls have been developed to simulate pulsatile dynamic responses to the cardiovascular experiments of the Skylab missions and to selected physiological stresses of manned space flight. Specific model simulations of the bicycle ergometry, lower body negative pressure, and tilt experiments have been developed and verified for 1-g response by comparison with available experimental data. The zero-g simulations of two Skylab experiments are discussed.

  19. Experiments and numerical simulation of mixing under supercritical conditions

    NASA Astrophysics Data System (ADS)

    Schmitt, T.; Rodriguez, J.; Leyva, I. A.; Candel, S.

    2012-05-01

    Supercritical pressure conditions designate a situation where the working fluid pressure is above the critical point. Among these conditions, it is interesting to identify a transcritical range which corresponds to cases where the pressure is above the critical point, but the injection temperature is below the critical value. This situation is of special interest because it raises fundamental issues which have technological relevance in the analysis of flows in liquid rocket engines. This situation is here envisaged by analyzing the behavior of a nitrogen shear coaxial jet comprising an inner stream injected at temperatures close to the critical temperature and a coaxial flow at a higher temperature. Experiments are carried out both in the absence of external modulation and by imposing a large amplitude transverse acoustic field. Real gas large eddy simulations are performed for selected experiments. The combination of experiments and calculations is used to evaluate effects of injector geometry and operating parameters. Calculations retrieve what is observed experimentally when the momentum flux ratio of the outer to the inner stream J= (ρ _eu_e^2)/(ρ _iu_i^2) is varied. Results exhibit the change in flow structure and the development of a recirculation region when this parameter exceeds a critical value. The instantaneous flow patterns for different momentum flux ratios are used in a second stage to characterize the dynamical behavior of the flow in terms of power spectral density of velocity and density fluctuations. Results obtained under acoustic modulation provide insight into mixing enhancement of coaxial streams with a view of its possible consequences in high frequency combustion instabilities. It is shown in particular that the presence of strong acoustic modulations notably reduces the high density jet core length, indicating an increased mixing efficiency. This behavior is more pronounced when the jet is placed at the location of maximum transverse

  20. Conceptual Issues in Quantifying Unusualness and Conceiving Stochastic Experiments: Insights from Students' Experiences in Designing Sampling Simulations

    ERIC Educational Resources Information Center

    Saldanha, Luis

    2016-01-01

    This article reports on a classroom teaching experiment that engaged a group of high school students in designing sampling simulations within a computer microworld. The simulation-design activities aimed to foster students' abilities to conceive of contextual situations as stochastic experiments, and to engage them with the logic of hypothesis…

  1. Conceptual Issues in Quantifying Unusualness and Conceiving Stochastic Experiments: Insights from Students' Experiences in Designing Sampling Simulations

    ERIC Educational Resources Information Center

    Saldanha, Luis

    2016-01-01

    This article reports on a classroom teaching experiment that engaged a group of high school students in designing sampling simulations within a computer microworld. The simulation-design activities aimed to foster students' abilities to conceive of contextual situations as stochastic experiments, and to engage them with the logic of hypothesis…

  2. Experience producing simulated events for the DZero experiment on the SAM-Grid

    SciTech Connect

    Garzoglio, G.; Terekhov, I.; Snow, J.; Jain, S.; Nishandar, A.; /Texas U., Arlington

    2004-12-01

    Most of the simulated events for the DZero experiment at Fermilab have been historically produced by the ''remote'' collaborating institutions. One of the principal challenges reported concerns the maintenance of the local software infrastructure, which is generally different from site to site. As the understanding of the distributed computing community over distributively owned and shared resources progresses, the adoption of grid technologies to address the production of Monte Carlo events for high energy physics experiments becomes increasingly interesting. SAM-Grid is a software system developed at Fermilab, which integrates standard grid technologies for job and information management with SAM, the data handling system of the DZero and CDF experiments. During the past few months, this grid system has been tailored for the Monte Carlo production of DZero. Since the initial phase of deployment, this experience has exposed an interesting series of requirements to the SAM-Grid services, the standard middleware, the resources and their management and to the analysis framework of the experiment. As of today, the inefficiency due to the grid infrastructure has been reduced to as little as 1%. In this paper, we present our statistics and the ''lessons learned'' in running large high energy physics applications on a grid infrastructure.

  3. Gas-grain simulation experiment module conceptual design and gas-grain simulation facility breadboard development

    NASA Technical Reports Server (NTRS)

    Zamel, James M.; Petach, Michael; Gat, Nahum; Kropp, Jack; Luong, Christina; Wolff, Michael

    1993-01-01

    This report delineates the Option portion of the Phase A Gas-Grain Simulation Facility study. The conceptual design of a Gas-Grain Simulation Experiment Module (GGSEM) for Space Shuttle Middeck is discussed. In addition, a laboratory breadboard was developed during this study to develop a key function for the GGSEM and the GGSF, specifically, a solid particle cloud generating device. The breadboard design and test results are discussed and recommendations for further studies are included. The GGSEM is intended to fly on board a low earth orbit (LEO), manned platform. It will be used to perform a subset of the experiments planned for the GGSF for Space Station Freedom, as it can partially accommodate a number of the science experiments. The outcome of the experiments performed will provide an increased understanding of the operational requirements for the GGSF. The GGSEM will also act as a platform to accomplish technology development and proof-of-principle experiments for GGSF hardware, and to verify concepts and designs of hardware for GGSF. The GGSEM will allow assembled subsystems to be tested to verify facility level operation. The technology development that can be accommodated by the GGSEM includes: GGSF sample generation techniques, GGSF on-line diagnostics techniques, sample collection techniques, performance of various types of sensors for environmental monitoring, and some off-line diagnostics. Advantages and disadvantages of several LEO platforms available for GGSEM applications are identified and discussed. Several of the anticipated GGSF experiments require the deagglomeration and dispensing of dry solid particles into an experiment chamber. During the GGSF Phase A study, various techniques and devices available for the solid particle aerosol generator were reviewed. As a result of this review, solid particle deagglomeration and dispensing were identified as key undeveloped technologies in the GGSF design. A laboratory breadboard version of a solid

  4. Small Arrays for Seismic Intruder Detections: A Simulation Based Experiment

    NASA Astrophysics Data System (ADS)

    Pitarka, A.

    2014-12-01

    Seismic sensors such as geophones and fiber optic have been increasingly recognized as promising technologies for intelligence surveillance, including intruder detection and perimeter defense systems. Geophone arrays have the capability to provide cost effective intruder detection in protecting assets with large perimeters. A seismic intruder detection system uses one or multiple arrays of geophones design to record seismic signals from footsteps and ground vehicles. Using a series of real-time signal processing algorithms the system detects, classify and monitors the intruder's movement. We have carried out numerical experiments to demonstrate the capability of a seismic array to detect moving targets that generate seismic signals. The seismic source is modeled as a vertical force acting on the ground that generates continuous impulsive seismic signals with different predominant frequencies. Frequency-wave number analysis of the synthetic array data was used to demonstrate the array's capability at accurately determining intruder's movement direction. The performance of the array was also analyzed in detecting two or more objects moving at the same time. One of the drawbacks of using a single array system is its inefficiency at detecting seismic signals deflected by large underground objects. We will show simulation results of the effect of an underground concrete block at shielding the seismic signal coming from an intruder. Based on simulations we found that multiple small arrays can greatly improve the system's detection capability in the presence of underground structures. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

  5. Cascade processes in stratified media: experiment and direct numerical simulation.

    NASA Astrophysics Data System (ADS)

    Sibgatullin, Ilias; Brouzet, Christophe; Joubaud, Sylvain; Ermanyuk, Evgeny; Dauxois, Thierry

    2016-04-01

    Internal gravity waves may transfer substantial part of energy in oceans and astrophysical objects, influence the background stratification, and angular momentum. Internal waves can be generated by convection in astrophysical objects, by tidal motion and interaction with orography in oceans. Internal and inertial waves obey similar system of equations. Due to very particular type of dispersive relation and the way internal waves are reflected from surfaces, in confined domains the monochromatic internal waves after sequence of reflections may form closed paths, the "wave attractors" [1]. Presently, linear theory of wave attractors is quite elaborated and a principal interest of research is focused on nonlinear regimes and unstable configurations, overturning events and mixing. We have performed direct numerical simulation of wave attractors which closely reproduces experiments [2] being carried out in Ecole Normal Superior de Lyon (ENS de Lyon). Direct numerical simulation is realized with the help of spectral element approach and code nek5000. Triadic resonance is confirmed as the first instability which appears on the most energetic ray of the attractor at sufficiently large forcing. With further increase of the forcing amplitude the daughter waves also become unstable resulting in a sophisticated cascade process which was first observed experimentally. For very high forcing amplitude interaction of focused waves with the walls results in appearance of small-scale folded structures. Their interaction with principal flow is the subject of further research. 1. Maas, L. R. M. & Lam, F.-P. A., Geometric focusing of internal waves. J. Fluid Mech, 1995,. 300, 1-41 2. Scolan, H., Ermanyuk, E., Dauxois, T., 2013, Physical Review Letters, 110, 234501

  6. SPAce Readiness Coherent Lidar Experiment: validation of observing system simulations

    NASA Astrophysics Data System (ADS)

    Emmitt, George D.; Miller, Timothy; Kavaya, Michael J.

    1998-12-01

    NASA recently approved a mission to fly a Doppler Wind Lidar on a US Space Shuttle. SPARCLE, managed by Marshall Space Flight Center in Huntsville, AL, is targeted for launch in March 2001. This mission is viewed as a necessary demonstration of a solid state lidar using coherent detection before committing resources to a 3-5 year research or operational mission. While, to many, this shuttle mission is seen as the first step in a series leading to a fully operational wind observing system, to others, it is a chance to validate predictions of performance based upon theoretical models, analyses of airborne and ground-based data and sophisticated observing system simulation experiments. The SPARCLE instrument is a 100 mJ, 6 Hz, diode pumped 2 micron laser with a .25 m telescope using heterodyne mixing in a fiber and an InGaAs detector. A 25 cm silicon wedge scanner will be used in step-stare modes with dwells ranging from 60 seconds to .5 seconds. Pointing knowledge is achieved with a dedicated GPS/INS mounted close to the lidar. NASA's hitchhiker program is providing the instrument enclosures and mission logistics support. An on- board data system in sized to record 80 Gbytes of raw signal from two 400 MHz A/D converters. On-board signal processing will be used to control the frequency of the Master Oscillator. SPARCLE is predicted to have a singleshot backscatter sensitivity near 5 by 10-6 m-1 sr-1. To achieve higher sensitivity, shot accumulation will be employed. Ground-based, 2 micron DWLs have been used to assess the benefits of shot accumulation. Airborne programs like MACAWS have provided good data st for evaluating various sampling strategies and signal processing algorithms. Using these real data to calibrate out simulation models, we can describe when and how well SPARCLE is expected to perform.

  7. Simulation of astrophysical jets in a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Bellan, Paul

    2006-04-01

    Astrophysical jets are routinely simulated in a reproducible, well-diagnosed laboratory experiment. The experimental sequence starts by imposing a vacuum poloidal magnetic field linking a disk electrode to a co-planar annular electrode. Neutral gas (H, Ne, N, or Ar) is then injected via 8 nozzles located on the disk and 8 nozzles on the annulus. A 120 μF capacitor bank power supply charged to 4-7 kV is applied via ignitron switches across the electrodes, breaking down the injected gas to form plasma. The low impedance (<10 mφ) of the highly conducting plasma causes the power supply to behave as a current source, rather than a voltage source. The discharging capacitor bank drives a ˜100 kA poloidal electric current through the plasma; this current initially flows in eight distinct `spider legs' (see photo in April meeting poster) that span from the disk to the annulus. The spider legs quickly merge via mutual attraction of their currents to form the simulated astrophysical jet. The axial gradient of the toroidal magnetic field energy density provides the force that accelerates the jet. The mass flux boundary condition at the electrodes is tightly coupled to the jet behavior. The jet is `fueled' by plasma ingested from the nozzles and the accumulation (pile-up) of the ingested plasma collimates the jet because of the associated pile-up of frozen-in toroidal magnetic flux convected with the plasma. The jet undergoes a kink instability when it becomes long enough to satisfy the Kruskal-Shafranov q=1 condition.

  8. Localized harmonic motion imaging: theory, simulations and experiments.

    PubMed

    Konofagou, Elisa E; Hynynen, Kullervo

    2003-10-01

    Several techniques have been developed in an effort to estimate mechanical properties of tissues. These techniques typically estimate static or harmonic motion resulting from an externally or internally applied mechanical stimulus. In this paper, we discuss the advantages of utilizing a new technique that performs radiofrequency (RF) signal tracking to estimate the localized oscillatory motion resulting from the harmonic radiation force produced by two focused ultrasound (US) transducer elements with overlapping beams oscillating at distinct frequencies. Finite-element and Monte-Carlo simulations were performed to characterize the range of oscillatory displacements produced by a harmonic radiation force. In the experimental verification, three transducers were used: two single-element focused transducers and one lead zirconate-titanate (PZT) composite 16-element probe. Four agar gels were utilized to determine the effect of stiffness on the motion amplitude. Estimates of the displacement relative to the initial position (i.e., at the onset of the application of the radiation force) were obtained during the application of the radiation force that oscillated at frequencies ranging between 200 Hz and 800 Hz. In the simulations, the estimated oscillatory displacement spanned from -800 to 600 microm and the frequencies of excitation could easily be estimated from the temporal variation of the displacement. In addition, a frequency upshift (on the order of tens of Hz) was estimated with stiffness increase. Furthermore, an exponential decrease of the displacement amplitude with stiffness was observed at all frequencies investigated. An M-mode version to depict both the spatial and temporal variations of the locally induced displacement was used. In experiments with gels of different stiffness, the resulting amplitude of the harmonic displacement estimated oscillated at the same frequencies and ranged from -300 to 250 microm. An exponential decrease of the displacement

  9. CLARREO shortwave observing system simulation experiments of the twenty-first century: Simulator design and implementation

    SciTech Connect

    Feldman, D.R.; Algieri, C.A.; Ong, J.R.; Collins, W.D.

    2011-04-01

    Projected changes in the Earth system will likely be manifested in changes in reflected solar radiation. This paper introduces an operational Observational System Simulation Experiment (OSSE) to calculate the signals of future climate forcings and feedbacks in top-of-atmosphere reflectance spectra. The OSSE combines simulations from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report for the NCAR Community Climate System Model (CCSM) with the MODTRAN radiative transfer code to calculate reflectance spectra for simulations of current and future climatic conditions over the 21st century. The OSSE produces narrowband reflectances and broadband fluxes, the latter of which have been extensively validated against archived CCSM results. The shortwave reflectance spectra contain atmospheric features including signals from water vapor, liquid and ice clouds, and aerosols. The spectra are also strongly influenced by the surface bidirectional reflectance properties of predicted snow and sea ice and the climatological seasonal cycles of vegetation. By comparing and contrasting simulated reflectance spectra based on emissions scenarios with increasing projected and fixed present-day greenhouse gas and aerosol concentrations, we find that prescribed forcings from increases in anthropogenic sulfate and carbonaceous aerosols are detectable and are spatially confined to lower latitudes. Also, changes in the intertropical convergence zone and poleward shifts in the subsidence zones and the storm tracks are all detectable along with large changes in snow cover and sea ice fraction. These findings suggest that the proposed NASA Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission to measure shortwave reflectance spectra may help elucidate climate forcings, responses, and feedbacks.

  10. LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL

    SciTech Connect

    Stephen M. Masutani

    1999-12-31

    This Final Technical Report summarizes the technical accomplishments of an investigation entitled ''Laboratory Experiments to Simulate CO{sub 2} Ocean Disposal'', funded by the U.S. Department of Energy's University Coal Research Program. This investigation responds to the possibility that restrictions on greenhouse gas emissions may be imposed in the future to comply with the Framework Convention on Climate Change. The primary objective of the investigation was to obtain experimental data that can be applied to assess the technical feasibility and environmental impacts of oceanic containment strategies to limit release of carbon dioxide (CO{sub 2}) from coal and other fossil fuel combustion systems into the atmosphere. A number of critical technical uncertainties of ocean disposal of CO{sub 2} were addressed by performing laboratory experiments on liquid CO{sub 2} jet break-up into a dispersed droplet phase, and hydrate formation, under deep ocean conditions. Major accomplishments of this study included: (1) five jet instability regimes were identified that occur in sequence as liquid CO{sub 2} jet disintegration progresses from laminar instability to turbulent atomization; (2) linear regression to the data yielded relationships for the boundaries between the five instability regimes in dimensionless Ohnesorge Number, Oh, and jet Reynolds Number, Re, space; (3) droplet size spectra was measured over the full range of instabilities; (4) characteristic droplet diameters decrease steadily with increasing jet velocity (and increasing Weber Number), attaining an asymptotic value in instability regime 5 (full atomization); and (5) pre-breakup hydrate formation appears to affect the size distribution of the droplet phase primary by changing the effective geometry of the jet.

  11. The INAF/IAPS Plasma Chamber for ionospheric simulation experiment

    NASA Astrophysics Data System (ADS)

    Diego, Piero

    2016-04-01

    The plasma chamber is particularly suitable to perform studies for the following applications: - plasma compatibility and functional tests on payloads envisioned to operate in the ionosphere (e.g. sensors onboard satellites, exposed to the external plasma environment); - calibration/testing of plasma diagnostic sensors; - characterization and compatibility tests on components for space applications (e.g. optical elements, harness, satellite paints, photo-voltaic cells, etc.); - experiments on satellite charging in a space plasma environment; - tests on active experiments which use ion, electron or plasma sources (ion thrusters, hollow cathodes, field effect emitters, plasma contactors, etc.); - possible studies relevant to fundamental space plasma physics. The facility consists of a large volume vacuum tank (a cylinder of length 4.5 m and diameter 1.7 m) equipped with a Kaufman type plasma source, operating with Argon gas, capable to generate a plasma beam with parameters (i.e. density and electron temperature) close to the values encountered in the ionosphere at F layer altitudes. The plasma beam (A+ ions and electrons) is accelerated into the chamber at a velocity that reproduces the relative motion between an orbiting satellite and the ionosphere (≈ 8 km/s). This feature, in particular, allows laboratory simulations of the actual compression and depletion phenomena which take place in the ram and wake regions around satellites moving through the ionosphere. The reproduced plasma environment is monitored using Langmuir Probes (LP) and Retarding Potential Analyzers (RPA). These sensors can be automatically moved within the experimental space using a sled mechanism. Such a feature allows the acquisition of the plasma parameters all around the space payload installed into the chamber for testing. The facility is currently in use to test the payloads of CSES satellite (Chinese Seismic Electromagnetic Satellite) devoted to plasma parameters and electric field

  12. Simulation of Seismic Tunnel Detection Experiments in Heterogeneous Geological Media

    NASA Astrophysics Data System (ADS)

    Sherman, C. S.; Glaser, S. D.; Rector, J.

    2013-12-01

    Detecting covert tunnels and other underground openings is an important yet challenging problem for geophysicists, especially where geological heterogeneity is pronounced. A number of geophysical methods have been employed to solve this problem, each with varying degrees of success. We focus on the near-surface seismic techniques of surface wave backscattering, surface wave attenuation tomography, body wave diffraction imaging, and resonant imaging. We use the elastodynamic wave propagation code E3D to simulate tunnel detection experiments completed at this site for a range of synthetic fractal velocity models. The Black Diamond mine, located near Pittsburg California, is used for the field test of our analysis. Our results show that for the relatively low-frequency surface wave attenuation and backscattering methods, the maximum detectable tunnel depth in a homogenous medium is approximately equal to the wavelength of the probing Rayleigh wave. The higher-frequency body wave diffraction and resonant imaging techniques are able to locate tunnels at greater depths, but require more sophisticated analysis and are prone to greater attenuation losses. As is expected, for large values of heterogeneity amplitude, ɛ, the percent standard deviation from the mean velocity model, the average observed surface wave attenuation signal decreases and the maximum detectable tunnel depth decreases. However, for moderate values of heterogeneity amplitude (ɛ < 3%), the average surface wave attenuation signal increases and the maximum detectable tunnel depth increases. For the body wave diffraction and resonant imaging experiments, as ɛ increases the complexity of the observed signal increases, resulting in more difficult processing and interpretation. The additional scattering attenuation tends to degrade the signals significantly due to their reliance on lower amplitude and higher frequency waves.

  13. Simulated Interactive Research Experiments as Educational Tools for Advanced Science

    NASA Astrophysics Data System (ADS)

    Tomandl, Mathias; Mieling, Thomas; Losert-Valiente Kroon, Christiane M.; Hopf, Martin; Arndt, Markus

    2015-09-01

    Experimental research has become complex and thus a challenge to science education. Only very few students can typically be trained on advanced scientific equipment. It is therefore important to find new tools that allow all students to acquire laboratory skills individually and independent of where they are located. In a design-based research process we have investigated the feasibility of using a virtual laboratory as a photo-realistic and scientifically valid representation of advanced scientific infrastructure to teach modern experimental science, here, molecular quantum optics. We found a concept based on three educational principles that allows undergraduate students to become acquainted with procedures and concepts of a modern research field. We find a significant increase in student understanding using our Simulated Interactive Research Experiment (SiReX), by evaluating the learning outcomes with semi-structured interviews in a pre/post design. This suggests that this concept of an educational tool can be generalized to disseminate findings in other fields.

  14. Simulated Interactive Research Experiments as Educational Tools for Advanced Science

    PubMed Central

    Tomandl, Mathias; Mieling, Thomas; Losert-Valiente Kroon, Christiane M.; Hopf, Martin; Arndt, Markus

    2015-01-01

    Experimental research has become complex and thus a challenge to science education. Only very few students can typically be trained on advanced scientific equipment. It is therefore important to find new tools that allow all students to acquire laboratory skills individually and independent of where they are located. In a design-based research process we have investigated the feasibility of using a virtual laboratory as a photo-realistic and scientifically valid representation of advanced scientific infrastructure to teach modern experimental science, here, molecular quantum optics. We found a concept based on three educational principles that allows undergraduate students to become acquainted with procedures and concepts of a modern research field. We find a significant increase in student understanding using our Simulated Interactive Research Experiment (SiReX), by evaluating the learning outcomes with semi-structured interviews in a pre/post design. This suggests that this concept of an educational tool can be generalized to disseminate findings in other fields. PMID:26370627

  15. On the consistency of scale among experiments, theory, and simulation

    DOE PAGES

    McClure, James E.; Dye, Amanda L.; Miller, Cass T.; ...

    2017-02-20

    As a tool for addressing problems of scale, we consider an evolving approach known as the thermodynamically constrained averaging theory (TCAT), which has broad applicability to hydrology. We consider the case of modeling of two-fluid-phase flow in porous media, and we focus on issues of scale as they relate to various measures of pressure, capillary pressure, and state equations needed to produce solvable models. We apply TCAT to perform physics-based data assimilation to understand how the internal behavior influences the macroscale state of two-fluid porous medium systems. A microfluidic experimental method and a lattice Boltzmann simulation method are used to examinemore » a key deficiency associated with standard approaches. In a hydrologic process such as evaporation, the water content will ultimately be reduced below the irreducible wetting-phase saturation determined from experiments. This is problematic since the derived closure relationships cannot predict the associated capillary pressures for these states. We demonstrate that the irreducible wetting-phase saturation is an artifact of the experimental design, caused by the fact that the boundary pressure difference does not approximate the true capillary pressure. Using averaging methods, we compute the true capillary pressure for fluid configurations at and below the irreducible wetting-phase saturation. Results of our analysis include a state function for the capillary pressure expressed as a function of fluid saturation and interfacial area.« less

  16. Solution structures of rat amylin peptide: simulation, theory, and experiment.

    PubMed

    Reddy, Allam S; Wang, Lu; Lin, Yu-Shan; Ling, Yun; Chopra, Manan; Zanni, Martin T; Skinner, James L; De Pablo, Juan J

    2010-02-03

    Amyloid deposits of amylin in the pancreas are an important characteristic feature found in patients with Type-2 diabetes. The aggregate has been considered important in the disease pathology and has been studied extensively. However, the secondary structures of the individual peptide have not been clearly identified. In this work, we present detailed solution structures of rat amylin using a combination of Monte Carlo and molecular dynamics simulations. A new Monte Carlo method is presented to determine the free energy of distinct biomolecular conformations. Both folded and random-coil conformations of rat amylin are observed in water and their relative stability is examined in detail. The former contains an alpha-helical segment comprised of residues 7-17. We find that at room temperature the folded structure is more stable, whereas at higher temperatures the random-coil structure predominates. From the configurations and weights we calculate the alpha-carbon NMR chemical shifts, with results that are in reasonable agreement with experiments of others. We also calculate the infrared spectrum in the amide I stretch regime, and the results are in fair agreement with the experimental line shape presented herein.

  17. Fluorescence correlation spectroscopy of repulsive systems: theory, simulation, and experiment.

    PubMed

    Feng, Ligang; Yang, Jingfa; Zhao, Jiang; Wang, Dapeng; Koynov, Kaloian; Butt, Hans-Jürgen

    2013-06-07

    The theoretical basis of fluorescence correlation spectroscopy (FCS) for repulsive systems, such as charged colloids or macromolecules, has been further expanded and developed. It is established that the collective correlation function can no longer be fitted using the theoretical model of non-interacting systems. Also, it is discovered that the collective correlation function can be divided into two parts: a self-part and a distinct-part, named as the self-correlation and cross-correlation function, respectively. The former indicates the self-diffusion of objects, while the latter describes mutual interactions. Dual-color fluorescence cross-correlation spectroscopy provides the direct measurements of the two parts. The particle concentration and mean squared displacement of single particles can be deduced from the self-correlation function, while the correlation volume between particles can be approximated from the cross-correlation function. In the case of charged colloids, the Debye length of the solution and particle surface charge number can be fitted from the cross-correlation function. These theoretical results are successfully proven using Brownian dynamics simulations and preliminary FCS experiments for model charged colloidal systems.

  18. Experiments and simulations of RT and RM fronts

    NASA Astrophysics Data System (ADS)

    Lopez, P.; Gushkov, S.

    2009-04-01

    Experimental and numerical results on the advance of a mixing or non-mixing front occurring at a density interface due to gravitational acceleration are analyzed considering the fractal and spectral structure of the front. The experimental configuration consists on a unstable two layer system held by a removable plate in a box for the Rayleigh-Taylor fronts and shock tube high Mach number impulse across a density interface air/SF6. The evolution of the turbulent mixing layer and its complex configuration is studied taking into account the dependence on the initial modes at the early stages and its spectral, self-similar information. Most models of the turbulent mixing evolution generated by hydrodynamics instabilities do not include any dependence on initial conditions, but in many relevant physical problems this dependence is very important, for instance, in Inertial Confinement Fussion target implosion. We discuss simple initial conditions (such as a jet array versus a plate removal) with the aid of numerical models. The analysis of Kelvin-Helmholtz, Rayleigh-Taylor, Richtmyer-Meshkov and of accelerated instabilities is presented locally, and seen to dominate the turbulent cascade mixing zone differently under different initial conditions. Fractal and neuron network analysis of Turbulent Mixing under RT and RM instabilities are presented comparing the different experiments and numerical simulations.

  19. On the consistency of scale among experiments, theory, and simulation

    NASA Astrophysics Data System (ADS)

    McClure, James E.; Dye, Amanda L.; Miller, Cass T.; Gray, William G.

    2017-02-01

    As a tool for addressing problems of scale, we consider an evolving approach known as the thermodynamically constrained averaging theory (TCAT), which has broad applicability to hydrology. We consider the case of modeling of two-fluid-phase flow in porous media, and we focus on issues of scale as they relate to various measures of pressure, capillary pressure, and state equations needed to produce solvable models. We apply TCAT to perform physics-based data assimilation to understand how the internal behavior influences the macroscale state of two-fluid porous medium systems. A microfluidic experimental method and a lattice Boltzmann simulation method are used to examine a key deficiency associated with standard approaches. In a hydrologic process such as evaporation, the water content will ultimately be reduced below the irreducible wetting-phase saturation determined from experiments. This is problematic since the derived closure relationships cannot predict the associated capillary pressures for these states. We demonstrate that the irreducible wetting-phase saturation is an artifact of the experimental design, caused by the fact that the boundary pressure difference does not approximate the true capillary pressure. Using averaging methods, we compute the true capillary pressure for fluid configurations at and below the irreducible wetting-phase saturation. Results of our analysis include a state function for the capillary pressure expressed as a function of fluid saturation and interfacial area.

  20. Simulated Interactive Research Experiments as Educational Tools for Advanced Science.

    PubMed

    Tomandl, Mathias; Mieling, Thomas; Losert-Valiente Kroon, Christiane M; Hopf, Martin; Arndt, Markus

    2015-09-15

    Experimental research has become complex and thus a challenge to science education. Only very few students can typically be trained on advanced scientific equipment. It is therefore important to find new tools that allow all students to acquire laboratory skills individually and independent of where they are located. In a design-based research process we have investigated the feasibility of using a virtual laboratory as a photo-realistic and scientifically valid representation of advanced scientific infrastructure to teach modern experimental science, here, molecular quantum optics. We found a concept based on three educational principles that allows undergraduate students to become acquainted with procedures and concepts of a modern research field. We find a significant increase in student understanding using our Simulated Interactive Research Experiment (SiReX), by evaluating the learning outcomes with semi-structured interviews in a pre/post design. This suggests that this concept of an educational tool can be generalized to disseminate findings in other fields.

  1. Simulation and experiment for large scale space structure

    NASA Astrophysics Data System (ADS)

    Sun, Hongbo; Zhou, Jian; Zha, Zuoliang

    2013-04-01

    The future space structures are relatively large, flimsy, and lightweight. As a result, they are more easily affected or distortion by space environments compared to other space structures. This study examines the structural integrity of a large scale space structure. A new design of transient temperature field analysis method of the developable reflector on orbit environment is presented, which simulates physical characteristic of developable antenna reflector with a high precision. The different kinds of analysis denote that different thermal elastic characteristics of different materials. The three-dimension multi-physics coupling transient thermal distortion equations for the antenna are founded based on the Galerkins method. For a reflector on geosynchronous orbit, the transient temperature field results from this method are compared with these from NASA. It follows from the analysis that the precision of this method is high. An experimental system is established to verify the control mechanism with IEBIS and thermal sensor technique. The shape control experiments are finished by measuring and analyzing developable tube. Results reveal that the temperature levels of the developable antenna reflector alternate greatly in the orbital period, which is about ±120° when considering solar flux ,earth radiating flux and albedo scattering flux.

  2. Solution Structures of Rat Amylin Peptide: Simulation, Theory, and Experiment

    PubMed Central

    Reddy, Allam S.; Wang, Lu; Lin, Yu-Shan; Ling, Yun; Chopra, Manan; Zanni, Martin T.; Skinner, James L.; De Pablo, Juan J.

    2010-01-01

    Abstract Amyloid deposits of amylin in the pancreas are an important characteristic feature found in patients with Type-2 diabetes. The aggregate has been considered important in the disease pathology and has been studied extensively. However, the secondary structures of the individual peptide have not been clearly identified. In this work, we present detailed solution structures of rat amylin using a combination of Monte Carlo and molecular dynamics simulations. A new Monte Carlo method is presented to determine the free energy of distinct biomolecular conformations. Both folded and random-coil conformations of rat amylin are observed in water and their relative stability is examined in detail. The former contains an α-helical segment comprised of residues 7–17. We find that at room temperature the folded structure is more stable, whereas at higher temperatures the random-coil structure predominates. From the configurations and weights we calculate the α-carbon NMR chemical shifts, with results that are in reasonable agreement with experiments of others. We also calculate the infrared spectrum in the amide I stretch regime, and the results are in fair agreement with the experimental line shape presented herein. PMID:20141758

  3. Laboratory Simulations Of Titan’s Atmospheric Chemistry With The NASA Ames Titan Haze Simulation Experiment

    NASA Astrophysics Data System (ADS)

    Sciamma-O'Brien, Ella; Contreras, C. S.; Ricketts, C. L.; Salama, F.

    2012-05-01

    Solar UV radiation and electron bombardment from Saturn’s magnetosphere dissociate nitrogen and methane in Titan’s atmosphere, leading to the production of heavier molecules and solid organic aerosols that contribute to the haze layers giving Titan its characteristic orange color. The detection of benzene and toluene, critical precursors of polycyclic aromatic hydrocarbon (PAH), in Titan’s ionosphere, by the Cassini INMS suggests that PAHs might play a role in the production of Titan’s aerosols. The Titan Haze Simulation (THS) experiment has been developed at NASA Ames’ Cosmic Simulation facility (COSmIC) to study the chemical pathways that link the simple molecules resulting from the first steps of the N2-CH4 chemistry (C2H2, C2H4, HCN..) to benzene, and to PAHs and nitrogen-containing PAHs (PANHs) as precursors to the production of solid aerosols. In the THS experiment, Titan’s atmospheric chemistry is simulated by plasma in the stream of a supersonic jet expansion. With this unique design, the gas mixture is cooled to Titan-like temperature ( 150K) before inducing the chemistry by plasma discharge. Different gas mixtures containing the first products of Titan’s N2-CH4 chemistry, but also much heavier molecules like PAHs or PANHs can be injected to study specific chemical reactions. The products of the chemistry are detected and studied using Cavity Ring Down Spectroscopy and Time-Of-Flight Mass Spectrometry. Thin tholin (Titan aerosol analogs) deposits are also produced in the THS experiment and can be analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Scanning Electron Microscopy (SEM). We present the results of mass spectrometry studies using different gas mixtures, and discuss their relevance for the study of specific pathways in Titan’s atmospheric chemistry. Acknowledgements: This research is supported by NASA PATM. E.S.O., C.S.C. and C.L.R acknowledge the support of the NASA Postdoctoral Program. The authors acknowledge the

  4. The Lived-Experience of Novice Nurse's Actualizing Clinical Reasoning in Academic Simulation

    ERIC Educational Resources Information Center

    Brinker, Mary Catherine

    2016-01-01

    The purpose of this existential-phenomenological study was to address the first-person perspective of what it is like to experience clinical reasoning during a simulation. It was not known how a novice nurse would describe the experience of actualizing clinical reasoning during the academic simulation experience. In order to maintain the…

  5. The Lived-Experience of Novice Nurse's Actualizing Clinical Reasoning in Academic Simulation

    ERIC Educational Resources Information Center

    Brinker, Mary Catherine

    2016-01-01

    The purpose of this existential-phenomenological study was to address the first-person perspective of what it is like to experience clinical reasoning during a simulation. It was not known how a novice nurse would describe the experience of actualizing clinical reasoning during the academic simulation experience. In order to maintain the…

  6. Infant rats with chronic neonatal isolation experience show decreased extracellular serotonin levels in ventral striatum at baseline and in response to cocaine.

    PubMed

    Kosten, Therese A; Zhang, Xiang Yang; Kehoe, Priscilla

    2004-08-18

    Previously, we demonstrated that the early life stress of neonatal isolation enhances extracellular dopamine (DA) levels in ventral striatum in response to psychostimulants in infant rats. Yet, neonatal isolation does not alter baseline DA levels. DA levels are affected by serotonin (5-HT) and striatal levels of this transmitter are also enhanced by cocaine. Other early life stresses are reported to alter various 5-HT neural systems. Thus, the purpose of this study is to test whether neonatal isolation alters ventral striatal 5-HT levels at baseline or in response to cocaine. Litters were subjected to neonatal isolation (1-h individual isolation/day on postnatal days 2-9) or to non-handled conditions and pups assigned to one of three cocaine doses (0, 2.5, or 5.0 mg/kg) groups. On postnatal day 10, probes were implanted in the ventral striatum. Dialysate samples obtained over a 60-min baseline period and for 120 min post cocaine injections were assessed for levels of 5-HT and its metabolite, 5-HIAA. ISO decreased ventral striatal 5-HT levels at baseline and after cocaine administration but did not alter 5-HIAA levels. These data add to the literature on the immediate effects of early life stress on 5-HT systems by showing alterations in the ventral striatal system. Because serotonergic effects in this neural area are associated with reward and with emotion and affect regulation, the results of this study suggest that early life stress may be a risk factor for addiction and other psychiatric disorders.

  7. Observation system simulation experiments using water vapor isotope information

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kei; Miyoshi, Takemasa; Kanamitsu, Masao

    2014-07-01

    Measurements of water vapor isotopes (δ18O and δD) have dramatically increased in recent years with the availability of new spectroscopic technology. To utilize these data more efficiently, this study first developed a new data assimilation system using a local transform ensemble Kalman filter (LETKF) and the Isotope-incorporated Global Spectral Model (IsoGSM). An observation system simulation experiment (OSSE) was then conducted. The OSSE used a synthetic data set of vapor isotope measurements, mimicking Tropospheric Emission Spectrometer (TES)-retrieved δD from the mid-troposphere, SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY)-retrieved δD from the water vapor column, and the virtual Global Network of Isotopes in Precipitation (GNIP)-like surface vapor isotope (both δD and δ18O) monitoring network. For TES and SCIAMACHY, we assumed a similar spatiotemporal coverage as that of the real data sets. For the virtual GNIP-like network, we assumed ~200 sites worldwide and 6-hourly measurements. An OSSE with 20 ensemble members was then conducted for January 2006. The results showed a significant improvement in not only the vapor isotopic field but also meteorological fields, such as wind speed, temperature, surface pressure, and humidity, when compared with a test with no observations. For surface air temperature, the global root mean square error has dropped by 10%, with 40-60% of the decrease occurring in the east-southeast Asia where the concentration of observations is relatively higher. When there is a conventional radiosonde network, the improvement gained by adding isotopic measurements was small but positive for all variables.

  8. Simulation of underwater explosion benchmark experiments with ALE3D

    SciTech Connect

    Couch, R.; Faux, D.

    1997-05-19

    Some code improvements have been made during the course of this study. One immediately obvious need was for more flexibility in the constitutive representation for materials in shell elements. To remedy this situation, a model with a tabular representation of stress versus strain and rate dependent effects was implemented. This was required in order to obtain reasonable results in the IED cylinder simulation. Another deficiency was in the ability to extract and plot variables associated with shell elements. The pipe whip analysis required the development of a scheme to tally and plot time dependent shell quantities such as stresses and strains. This capability had previously existed only for solid elements. Work was initiated to provide the same range of plotting capability for structural elements that exist with the DYNA3D/TAURUS tools. One of the characteristics of these problems is the disparity in zoning required in the vicinity of the charge and bubble compared to that needed in the far field. This disparity can cause the equipotential relaxation logic to provide a less than optimal solution. Various approaches were utilized to bias the relaxation to obtain more optimal meshing during relaxation. Extensions of these techniques have been developed to provide more powerful options, but more work still needs to be done. The results presented here are representative of what can be produced with an ALE code structured like ALE3D. They are not necessarily the best results that could have been obtained. More experience in assessing sensitivities to meshing and boundary conditions would be very useful. A number of code deficiencies discovered in the course of this work have been corrected and are available for any future investigations.

  9. Experiments for comparison of small scale rainfall simulators

    NASA Astrophysics Data System (ADS)

    Iserloh, T.; Ries, J. B.

    2012-04-01

    Small scale portable rainfall simulators are an essential tool in research of recent process dynamics of soil erosion. Such rainfall simulators differ in design, rainfall intensities, rain spectra etc., impeding comparison of the results. Due to different research questions a standardisation of rainfall simulation is not in sight. Nevertheless, the data become progressively important for soil erosion modelling and therefore the basis for decision-makers in application-oriented erosion protection. The project aims at providing a criteria catalogue for estimation of the different simulators as well as the comparability of the results and a uniform calibration procedure for generated rainfall. Within the project "Comparability of simulation results of different rainfall simulators as input data for soil erosion modelling (Deutsche Forschungsgemeinschaft - DFG, Project No. Ri 835/6-1)" many rainfall simulators used by European research groups were compared. The artificially generated rainfall of the rainfall simulators at the Universities Basel, La Rioja, Malaga, Trier, Tübingen, Valencia, Wageningen, Zaragoza and at different Spanish CSIC-institutes (Almeria, Cordoba, Granada, Murcia, Zaragoza) were measured with the same methods (Laser Precipitation Monitor for drop spectra and rain collectors for spatial distribution). The data are very beneficial for improvements of simulators and comparison of simulators and results. Furthermore, they can be used for comparative studies with natural rainfall spectra. A broad range of rainfall data was measured (e.g. intensity: 30 - 149 mmh-1, Christiansen Coefficient for spatial rainfall distribution 61 - 98 %, mean drop diameter 0.375 - 5.0 mm, mean kinetic energy expenditure 25 - 1322 J m-2 h-1, mean kinetic energy per unit area and unit depth of rainfall 4 - 14 J m-2 mm-1). Similarities among the simulators could be found e.g. concerning drop size distributions (maximum drop numbers are reached within the two smallest drop

  10. Constructing maternal-child learning experiences using clinical simulations.

    PubMed

    Jeffries, Pamela R; Bambini, Deborah; Hensel, Desiree; Moorman, Megan; Washburn, Joy

    2009-01-01

    Clinical simulations are gaining more attention in the field of maternal-child health and allow nursing programs and service organizations to assess competency of students and staff in key patient safety situations. Nursing and midwifery programs, orientations, and yearly reaccreditation modules commonly include simulation on postpartum hemorrhage, placenta abruption, shoulder distocia, and other high-risk, low-incidence emergency events. This article describes the use of simulations by educators and managers as teaching or professional development strategies.

  11. Coupled Simulations, Ground-Based Experiments and Flight Experiments for Astrodynamics Research

    NASA Astrophysics Data System (ADS)

    Boyce, R.; Brown, M.; Lorrain, P.; Capon, C.; Lambert, A.; Benson, C.; Tuttle, S.; Griffin, D.

    Near-Earth satellites undergo complex and poorly understood interactions with their environment, leading to large uncertainties in predicting orbits and an associated risk of collision with other satellites and with space debris. The nature, evolution and behaviour of the growing cloud of space debris in that environment is even less well understood. Significant effort and expenditure is currently being made by governments in Australia, UK, USA, Europe and elsewhere in space surveillance and tracking, in order to mitigate the risk. However, a major gap exists with respect to the science of in-orbit behaviour. Research is underway in Australia to enable the prediction of the orbits of near-Earth space objects with order(s) of magnitude greater fidelity than currently possible. This is being achieved by coupling together the necessary parts of the puzzle - the physics of rarefied space object “aerodynamics” and the space physics and space weather that affects it - and employing our capabilities in ground-based and in-orbit experiments, ground-based observations and high performance computing to do so. As part of the effort, UNSW Canberra is investing $10M to develop a sustainable university-led program to develop and fly affordable in-orbit missions for space research. In the coming 6 years, we will fly a minimum of four cubesat missions, some in partnership with DSTO, which will include flight experiments for validating Space Situational Awareness astrodynamics simulation and observation capabilities. The flights are underpinned by ground-based experimental research employing space test chambers, advanced diagnostics, and supercomputer simulations that couple DSMC and Particle-in-Cell methods for modelling space object interactions with the ionosphere. This paper will describe the research both underway and planned, with particular emphasis on the coupled numerical/experimental/flight approach.

  12. The Titan Haze Simulation experiment: laboratory simulation of Titan's atmospheric chemistry at low temperature

    NASA Astrophysics Data System (ADS)

    Sciamma-O'Brien, E.; Contreras, C. S.; Ricketts, C. L.; Salama, F.

    2012-04-01

    In Titan’s atmosphere, a complex organic chemistry between its two main constituents, N2 and CH4, leads to the production of heavy molecules and subsequently to solid organic aerosols. Several instruments onboard Cassini have detected neutral, positively and negatively charged particles and heavy molecules in the ionosphere of Titan[1,2]. In particular, the presence of benzene (C6H6) and toluene (C6H5CH3)[3], which are critical precursors of polycyclic aromatic hydrocarbon (PAH) compounds, suggests that PAHs might play a role in the production of Titan’s aerosols. The Titan Haze Simulation (THS) experiment has been developed at NASA Ames’ Cosmic Simulation facility (COSmIC) to study the chemical pathways that link the simple precursor molecules resulting from the first steps of the N2-CH4 chemistry (C2H2, C2H4, HCN…) to benzene, and to PAHs and nitrogen-containing PAHs (or PANHs) as precursors to the production of solid aerosols. In the THS experiment, Titan’s atmospheric chemistry is simulated by plasma in the stream of a supersonic jet expansion. With this unique design, the gas mixture is cooled to Titan-like temperature (~150K) before inducing the chemistry by plasma discharge. Different gas mixtures containing the first products of Titan’s N2-CH4 chemistry but also much heavier molecules like PAHs or PANHs can be injected to study specific chemical reactions. The products of the chemistry are detected and studied using two complementary techniques: Cavity Ring Down Spectroscopy[4] and Time-Of-Flight Mass Spectrometry[5]. Thin tholin deposits are also produced in the THS experiment and can be analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) and Scanning Electron Microscopy (SEM). We will present the results of ongoing mass spectrometry studies on the THS experiment using different gas mixtures: N2-CH4, N2-C2H2, N2-C2H4, N2-C2H6, N2-C6H6, and similar mixtures with an N2-CH4 (90:10) mixture instead of pure N2, to study specific pathways

  13. Accelerated Laboratory Research Experience in Psychology through Simulation.

    ERIC Educational Resources Information Center

    Chatfield, Douglas C.; Cruse, Bradley H.

    1986-01-01

    Describes implementation of computer simulation to aid in training psychology students in research methodology. Four skills required in research are reviewed; the simulation's context and the software used are described; and student activities, including submission of articles to online class journals and students' responses to the method, are…

  14. Computer Systems Simulation in Education: Description of an Experience.

    ERIC Educational Resources Information Center

    Toval, Ambrosio; Flores, Mariano

    1987-01-01

    Description of Atenea, the Spanish National Project for Computers in Education, focuses on the use of computer simulation and modeling in elementary and secondary education. Highlights include system dynamics, training courses for teachers, a microcomputer-based software package called System Dynamics Simulator for Education (SDSE), and a list of…

  15. Brownfield Action: An Integrated Environmental Science Simulation Experience for Undergraduates.

    ERIC Educational Resources Information Center

    Kelsey, Ryan

    This paper presents the results of three years of development and evaluation of a CD-ROM/Web hybrid simulation known as Brownfield Action for an introductory environmental science course at an independent college for women in the northeastern United States. Brownfield Action is a simulation that provides a learning environment for developing the…

  16. The Impact of Goal Setting on Team Simulation Experience.

    ERIC Educational Resources Information Center

    Fandt, Patricia M.; And Others

    1990-01-01

    Describes a study that examined the effects of goal setting on undergraduate students competing in a computerized business simulation. Group cohesiveness is discussed, treatments for the experimental and control groups are described, perceived team success is measured, and team simulation performance is evaluated. (30 references) (LRW)

  17. ACES: The ASCENDS CarbonHawk Experiment Simulator

    NASA Astrophysics Data System (ADS)

    Obland, M. D.; Prasad, N. S.; Harrison, F. W.; Browell, E. V.; Ismail, S.; Dobler, J. T.; Moore, B.; Zaccheo, T.; Campbell, J.; Chen, S.; Cleckner, C. S.; DiJoseph, M.; Little, A.; Notari, A.; Refaat, T. F.; Rosenbaum, D.; Vanek, M. D.; Bender, J.; Braun, M.; Chavez-Pirson, A.; Neal, M.; Rayner, P. J.; Rosiewicz, A.; Shure, M.; Welch, W.

    2012-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) a high bandwidth detector, (2) a multi-aperture telescope assembly, (3) advanced algorithms for cloud and aerosol discrimination, and (4) high-efficiency, multiple-amplifier CO2 and O2 laser transmitters. The instrument architecture will be developed to operate on a high-altitude aircraft and will be directly scalable to meet the ASCENDS mission requirements. These technologies are viewed as critical towards developing an airborne simulator and eventual spaceborne instrument with lower size, mass, and power consumption, and improved performance. The detector effort will improve the existing detector subsystem by increasing its bandwidth to a goal of 5 MHz, reducing its overall mass from 18 lbs to <10 lbs, and stretching the duration of autonomous, service-free operation periods from 4 hrs to >24 hrs. The development goals are to permit higher laser modulation rates, which provides greater flexibility for implementing thin-cloud discrimination algorithms as well as improving range resolution and error reduction, and to enable long flights on a high-altitude unmanned aerial vehicle (UAV). The telescope development consists of a three-telescope design built for the constraints of the Global Hawk aircraft. This task addresses the ability of multiple smaller telescopes to provide equal or greater collection efficiency compared with a single larger telescope with a reduced impact on launch mass and cost. The telescope assembly also integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical

  18. Simulation-guided cardiac auscultation improves medical students' clinical skills: the Pavia pilot experience.

    PubMed

    Perlini, Stefano; Salinaro, Francesco; Santalucia, Paola; Musca, Francesco

    2014-03-01

    Clinical evaluation is the cornerstone of any cardiac diagnosis, although excessive over-specialisation often leads students to disregard the value of clinical skills, and to overemphasize the approach to instrumental cardiac diagnosis. Time restraints, low availability of "typical" cardiac patients on whom to perform effective bedside teaching, patients' respect and the underscoring of the value of clinical skills all lead to a progressive decay in teaching. Simulation-guided cardiac auscultation may improve clinical training in medical students and residents. Harvey(©) is a mannequin encompassing more than 50 cardiac diagnoses that was designed and developed at the University of Miami (Florida, USA). One of the advantages of Harvey(©) simulation resides in the possibility of listening, comparing and discussing "real" murmurs. To objectively assess its teaching performance, the capability to identify five different cardiac diagnoses (atrial septal defect, normal young subject, mitral stenosis with tricuspid regurgitation, chronic mitral regurgitation, and pericarditis) out of more than 50 diagnostic possibilities was assessed in 523 III-year medical students (i.e. at the very beginning of their clinical experience), in 92 VI-year students, and in 42 residents before and after a formal 10-h teaching session with Harvey(©). None of them had previously experienced simulation-based cardiac auscultation in addition to formal lecturing (all three groups) and bedside teaching (VI-year students and residents). In order to assess the "persistence" of the acquired knowledge over time, the test was repeated after 3 years in 85 students, who did not repeat the formal 10-h teaching session with Harvey(©) after the III year. As expected, the overall response was poor in the "beginners" who correctly identified 11.0 % of the administered cardiac murmurs. After simulation-guided training, the ability to recognise the correct cardiac diagnoses was much better (72.0 %; p < 0

  19. Developing RESRAD-BASELINE for environmental baseline risk assessment

    SciTech Connect

    Cheng, Jing-Jy

    1995-12-31

    RESRAD-BASELINE is a computer code developed at Argonne developed at Argonne National Laboratory for the US Department of Energy (DOE) to perform both radiological and chemical risk assessments. The code implements the baseline risk assessment guidance of the US Environmental Protection Agency (EPA 1989). The computer code calculates (1) radiation doses and cancer risks from exposure to radioactive materials, and (2) hazard indexes and cancer risks from exposure to noncarcinogenic and carcinogenic chemicals, respectively. The user can enter measured or predicted environmental media concentrations from the graphic interface and can simulate different exposure scenarios by selecting the appropriate pathways and modifying the exposure parameters. The database used by PESRAD-BASELINE includes dose conversion factors and slope factors for radionuclides and toxicity information and properties for chemicals. The user can modify the database for use in the calculation. Sensitivity analysis can be performed while running the computer code to examine the influence of the input parameters. Use of RESRAD-BASELINE for risk analysis is easy, fast, and cost-saving. Furthermore, it ensures in consistency in methodology for both radiological and chemical risk analyses.

  20. Sequentially Simulated Outcomes: Kind Experience versus Nontransparent Description

    ERIC Educational Resources Information Center

    Hogarth, Robin M.; Soyer, Emre

    2011-01-01

    Recently, researchers have investigated differences in decision making based on description and experience. We address the issue of when experience-based judgments of probability are more accurate than are those based on description. If description is well understood ("transparent") and experience is misleading ("wicked"), it…

  1. Status of the NASA GMAO Observing System Simulation Experiment

    NASA Technical Reports Server (NTRS)

    Prive, Nikki C.; Errico, Ronald M.

    2014-01-01

    An Observing System Simulation Experiment (OSSE) is a pure modeling study used when actual observations are too expensive or difficult to obtain. OSSEs are valuable tools for determining the potential impact of new observing systems on numerical weather forecasts and for evaluation of data assimilation systems (DAS). An OSSE has been developed at the NASA Global Modeling and Assimilation Office (GMAO, Errico et al 2013). The GMAO OSSE uses a 13-month integration of the European Centre for Medium- Range Weather Forecasts 2005 operational model at T511/L91 resolution for the Nature Run (NR). Synthetic observations have been updated so that they are based on real observations during the summer of 2013. The emulated observation types include AMSU-A, MHS, IASI, AIRS, and HIRS4 radiance data, GPS-RO, and conventional types including aircraft, rawinsonde, profiler, surface, and satellite winds. The synthetic satellite wind observations are colocated with the NR cloud fields, and the rawinsondes are advected during ascent using the NR wind fields. Data counts for the synthetic observations are matched as closely as possible to real data counts, as shown in Figure 2. Errors are added to the synthetic observations to emulate representativeness and instrument errors. The synthetic errors are calibrated so that the statistics of observation innovation and analysis increments in the OSSE are similar to the same statistics for assimilation of real observations, in an iterative method described by Errico et al (2013). The standard deviations of observation minus forecast (xo-H(xb)) are compared for the OSSE and real data in Figure 3. The synthetic errors include both random, uncorrelated errors, and an additional correlated error component for some observational types. Vertically correlated errors are included for conventional sounding data and GPS-RO, and channel correlated errors are introduced to AIRS and IASI (Figure 4). HIRS, AMSU-A, and MHS have a component of horizontally

  2. Observation System Simulation Experiment (OSSE) using water vapor isotopes

    NASA Astrophysics Data System (ADS)

    Yoshimura, K.

    2013-12-01

    Measurements of water vapor isotopes (δ18O and δD) have been drastically increased these years with new technology, i.e., spectroscopic instruments both satellite-onboard and ground-based (in-situ) to improve our understanding of the hydrologic cycle in the atmosphere and land surface. To more efficiently utilize these data, this study first developed a new data assimilation system with Local Transform Ensemble Kalman Filter (LETKF) and Isotope-incorporated Global Spectral Model (IsoGSM). Then an observation system simulation experiment (OSSE) was conducted. This OSSE uses a mock dataset of vapor isotope measurements, namely TES/Aura retrieved δD at mid-troposphere, SCIAMACHY/Envisat retrieved δD at vapor column, and virtual GNIP-like vapor isotope (both δD and δ18O) monitoring network. We used historical retrieval numbers for TES and SCIAMACHY measurements, which are 15,000 and 10,000 data in January 2006. For virtual GNIP-like network, we assumed about 200 sites over the world, and 6-hourly measurement at 2m from surface. The accuracy of the measurements are 10‰ and 100‰ for δ18O and δD, respectively, including the uncertainty associated with representativeness of the data in space and time. Then the OSSE with 20 ensemble member was conducted for January 2006. The results are indeed remarkable. It showed significant improvement in not only vapor isotopic field but also meteorological fields, such as wind speed, temperature, surface pressure and humidity, comparing with a test without any observation. For surface air temperature, the global RMSE has dropped 10%, in which as large as 40-60% decrease is observed in east-southeast Asia area where the observation concentration is relatively higher. Most of the variables showed consistently similar feature. These results clearly show that the vapor isotope measurement definitely help to improve our understanding of hydrologic cycle through constraining with the data assimilation. RMSE of 6-hourly data for 2

  3. NPP training simulators in Hungary experience in development and utilization

    SciTech Connect

    Janosy, J.S.

    1996-11-01

    The construction of the only NPP in Hungary - the Paks NPP - started in 1975. The four units of VVER-440/213 were connected to the grid in 1982, 1984, 1986 and 1987. During the construction no simulator has been delivered with the power plant. Moreover, there were no state-of-art simulators in Central and Eastern Europe and in the former Soviet Union; not for the given type, not for civil use. The only simulator for the VVER-440 existing that time was made for the Loviisa NPP in Finland. This plant is not very similar to the Paks NPP; moreover, the pressure suppression system in the hermetical part of the primary circuit, the instrumentation and control systems, the main control room and the secondary circuit are completely different. Anyway, the training of Paks operators on this simulator was out of question - regardless the similarity problems. The design of the Paks NPP was made in the Soviet Union, therefore not too much design information was available in Hungary. During the creation of simulation models the authors had to rely mostly on common theory and measured performance. Besides the efforts to create a basic principle, full-scope replica and compact simulators there was a great need to use verified codes with more detailed models for better understanding the behavior and for evaluation of the safety. Thanks to these great efforts, the simulators were expanded to evaluate the performance of the trainees, for simulation of SBLOCA and LBLOCA events; the authors are checking and validating the operational procedures; soon they start the design of the functions of a new reactor protection system and they participate in international efforts to deliver training simulators to other VVER-440 power plants. The paper gives an overview of all these activities, referring to some key publications for each of them.

  4. Simulation of Extreme Arctic Cyclones in IPCC AR5 Experiments

    DTIC Science & Technology

    2014-05-15

    cyclones and identify changes in the characteristics of these storms caused by greenhouse -forced climate change to present. OBJECTIVES These goals...How well do state-of-the-art GCMs simulate them? (3) Are extreme Arctic cyclones already showing a response to greenhouse forcing? APPROACH These...study used 14 GCMs with widely varying horizontal and vertical resolutions and physics packages. These simulations were compared with an atmospheric

  5. Floret Test, Numerical Simulations of the Dent, Comparison with Experiments

    SciTech Connect

    Lefrancois, A.; Cutting, J.; Gagliardi, F.; Tarver, C.; Tran, T.

    2006-02-14

    The Floret test has been developed as a screening test to study the performance of a small amount of HE. Numerical simulations have been performed recently using CTH. The objective of this study is to perform numerical simulations in order to better understand the shock waves interactions, involved in the dent formation. Different 3D wedge configurations have been tested using the Ignition and Growth reactive flow model for the HE receptor with Ls-Dyna.

  6. Learning Oceanography from a Computer Simulation Compared with Direct Experience at Sea

    ERIC Educational Resources Information Center

    Winn, William; Stahr, Frederick; Sarason, Christian; Fruland, Ruth; Oppenheimer, Peter; Lee, Yen-Ling

    2006-01-01

    Considerable research has compared how students learn science from computer simulations with how they learn from "traditional" classes. Little research has compared how students learn science from computer simulations with how they learn from direct experience in the real environment on which the simulations are based. This study compared two…

  7. Using Microcomputer Game-Simulation Experiments to Study Family Response to Mt. St. Helens Eruptions.

    ERIC Educational Resources Information Center

    Ekker, Knut; And Others

    1988-01-01

    Explains how computerized game-simulation experiments were conducted to ascertain responses to the 1980 eruptions of Mt. St. Helens (Washington). Results indicate different aspects of individual preferences and family decisions with respect to relocation: (1) highly consistent in the game simulation; (2) responsive to the simulated threat; and (3)…

  8. Learning Oceanography from a Computer Simulation Compared with Direct Experience at Sea

    ERIC Educational Resources Information Center

    Winn, William; Stahr, Frederick; Sarason, Christian; Fruland, Ruth; Oppenheimer, Peter; Lee, Yen-Ling

    2006-01-01

    Considerable research has compared how students learn science from computer simulations with how they learn from "traditional" classes. Little research has compared how students learn science from computer simulations with how they learn from direct experience in the real environment on which the simulations are based. This study compared two…

  9. Integrating molecular dynamics simulations with chemical probing experiments using SHAPE-FIT

    PubMed Central

    Kirmizialtin, Serdal; Hennelly, Scott P.; Schug, Alexander; Onuchic, Jose N.; Sanbonmatsu, Karissa Y.

    2016-01-01

    Integration and calibration of molecular dynamics simulations with experimental data remains a challenging endeavor. We have developed a novel method to integrate chemical probing experiments with molecular simulations of RNA molecules by using a native structure-based model. Selective 2’-hydroxyl acylation by primer extension (SHAPE) characterizes the mobility of each residue in the RNA. Our method, SHAPE-FIT, automatically optimizes the potential parameters of the forcefield according to measured reactivities from SHAPE. The optimized parameter set allows simulations of dynamics highly consistent with SHAPE probing experiments. Such atomistic simulations, thoroughly grounded in experiment, can open a new window on RNA structure-function relations. PMID:25726467

  10. Validation of the Effectiveness of Simulator Experience vs Real-World Operational Experience in the Port of Valdez.

    DTIC Science & Technology

    1982-11-01

    Off Frack )eviation for Subjects with Simu- for Subjects with Valde: lator and No Simulator and No Valdez rhxperience 0 Experience The commonly...Radar Signal Generator, which potential danger . Such experiments can synthesizes video signals to stim- be performed safely and easily at ulate the

  11. Effect of Baseline Characteristics on the Outcome of Stent Retriever-Based Thrombectomy in Acute Basilar Artery Occlusions: A Single-Center Experience and Pooled Data Analysis.

    PubMed

    Wen, Wan-Ling; Li, Zi-Fu; Zhang, Yong-Wei; Yang, Peng-Fei; Simfukwe, Keith; Fang, Yi-Bin; Zhang, Tian-Yi; Deng, Ben-Qiang; Hong, Bo; Liu, Jian-Min; Huang, Qing-Hai

    2017-08-01

    To explore the association of baseline characteristics and the outcome of patients with acute basilar artery occlusion (BAO) after stent retriever-based thrombectomy (SRT). Clinical and imaging information of consecutive SRT-treated patients with BAO from a comprehensive stroke center and up-to-date literature were reviewed respectively. The impact of baseline variables toward favorable outcome was evaluated using subgroup analysis and odds ratio (OR) extracted from published data together with single-center records using pooled analysis. Nineteen cases from our center and 15 published studies involving 487 cases were included. Estimated pooled favorable outcome rate was 0.3746 (95% confidence interval [CI], 0.3165-0.4327), mortality was 0.2950 (95% CI, 0.2390-0.3510). Pooled estimates showed that successful reperfusion (modified thrombolysis in cerebral ischemia scale 2b or 3) gained by SRT alone was 0.7317 (95% CI, 0.6532-0.8102) and final successful reperfusion rate with or without additional reperfusion procedures was 0.8834 (95% CI, 0.8279-0.9390). Univariate analysis indicated that patients with successful reperfusion (OR, 2.05; P = 0.05), distal segment occlusion (OR, 2.03; P = 0.03), and cardioembolus origin (OR, 2.13; P = 0.01) were more likely to have favorable outcome (modified Rankin Scale score ≤2 at 3 months). Study series that applied intra-arterial thrombolysis, angioplasty, or stenting as rescuing therapy had higher successful reperfusion rate but they did not show a higher rate of favorable outcome. SRT with or without additional treatment appeared to be effective for the treatment of BAO. Successful reperfusion, distal segment occlusion, and cardiac embolism were associated with favorable outcome. The overall benefit of lesions requiring additional reperfusion therapy was unclear. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Precision surveying using very long baseline interferometry

    NASA Technical Reports Server (NTRS)

    Ryan, J. W.; Clark, T. A.; Coates, R.; Ma, C.; Robertson, D. S.; Corey, B. E.; Counselman, C. C.; Shapiro, I. I.; Wittels, J. J.; Hinteregger, H. F.

    1977-01-01

    Radio interferometry measurements were used to measure the vector baselines between large microwave radio antennas. A 1.24 km baseline in Massachusetts between the 36 meter Haystack Observatory antenna and the 18 meter Westford antenna of Lincoln Laboratory was measured with 5 mm repeatability in 12 separate experiments. Preliminary results from measurements of the 3,928 km baseline between the Haystack antenna and the 40 meter antenna at the Owens Valley Radio Observatory in California are presented.

  13. Validation experiments for LBM simulations of electron beam melting

    NASA Astrophysics Data System (ADS)

    Ammer, Regina; Rüde, Ulrich; Markl, Matthias; Jüchter, Vera; Körner, Carolin

    2014-05-01

    This paper validates three-dimensional (3D) simulation results of electron beam melting (EBM) processes by comparing experimental and numerical data. The physical setup is presented which is discretized by a 3D thermal lattice Boltzmann method (LBM). An experimental process window is used for the validation depending on the line energy injected into the metal powder bed and the scan velocity of the electron beam. In the process window, the EBM products are classified into the categories, porous, good and swelling, depending on the quality of the surface. The same parameter sets are used to generate a numerical process window. A comparison of numerical and experimental process windows shows a good agreement. This validates the EBM model and justifies simulations for future improvements of the EBM processes. In particular, numerical simulations can be used to explain future process window scenarios and find the best parameter set for a good surface quality and dense products.

  14. Advanced simulations of application plasmas: Comparisons with experiments and validations

    NASA Astrophysics Data System (ADS)

    Lee, Jae Koo

    2005-10-01

    Continuum-fluid and particle-in-cell models are the numerical simulation techniques commonly used for simulating low-temperature plasmas for plasma technology applications. Simulations can often identify research guidelines and propose novel designs leading to performance improvements in different plasma systems. We present an overview of the principles, strengths and limitations of the these. These modeling results are benchmarked by comparing in different plasma systems (capacitively and inductively coupled plasmas) with experimentally measured data and with other numerical results. The potential profile and the electron/ion kinetic information such as electron/ion energy distributions and temperatures are important for understanding the plasma phenomena. Kinetic 1d particle-in-cell/Monte-Carlo-collision and fluid modelings of Ar-oxygen plasma sources are carried out in the wide parameter range.

  15. Developing scintillation light readout simulation for the SBND experiment

    NASA Astrophysics Data System (ADS)

    Garcia-Gamez, D.

    2016-01-01

    Detection of scintillation light can play several important roles in LArTPCs. Increased collection efficiency could result in the improvement of time, energy, and position resolution. The SBND collaboration is developing detailed MC simulations to study the performance of different types of light systems in the LArSoft framework. Due to the vast number of photons typically produced in neutrino physics events, a full optical simulation becomes extremely hard to run on reasonable time scales. I will describe how the SBND simulation tackles these problems and its current status for two of the light detection systems considered by SBND: (i) a traditional TPB-coated PMT based system and (ii) a system based on TPB-coated reflector foils to increase collection efficiency without increasing the number of photodetectors.

  16. Reflectance confocal microscopy of red blood cells: simulation and experiment.

    PubMed

    Zeidan, Adel; Yelin, Dvir

    2015-11-01

    Measuring the morphology of red blood cells is important for clinical diagnosis, providing valuable indications on a patient's health. In this work, we have simulated the appearance of normal red blood cells under a reflectance confocal microscope and discovered unique relations between the morphological parameters and the resulting characteristic interference patterns of the cell. The simulation results showed good agreement with in vitro reflectance confocal images of red blood cells, acquired using spectrally encoded flow cytometry that imaged the cells in a linear flow without artificial staining. By matching the simulated patterns to confocal images of the cells, this method could be used for measuring cell morphology in three dimensions and for studying their physiology.

  17. Experiment and simulation of micromilling process for plastic material

    NASA Astrophysics Data System (ADS)

    Sun, Yazhou; Meng, Qingxin; Liu, Haitao

    2009-05-01

    According to elastic-plastic finite element theory, micro-milling nonlinear elastic-plastic finite element simulation analysis on micro-optical component material aluminum alloy 2A12 is carried out.Simulation and analysis on milling force, milling temperature, minimum chip thickness of micro-milling have been done, which provide the basis for improving machining accuracy of micro-optical component. Use Johnson-Cook's coupled thermal-mechanical model to build micro milling processing two-dimensional finite element model. By means of FEM analysis, simulation results under different rotating speed, different feed per tooth, different tool edge radius are obtained and analyzed. By this way, influencing regularities of kinds of factors on milling force and milling temperature are obtained. Finally experimental study on influencing factors of milling force is done.

  18. Gold-Palladium core@shell nanoalloys: experiments and simulations

    PubMed Central

    Spitale, A.; Perez, M. A.; Mejía-Rosales, S.; Yacamán, M. J.

    2015-01-01

    In this work, we report a facile synthesis route, structural characterization, and full atomistic simulations of gold-palladium nanoalloys. Through aberration corrected-STEM, UV-vis and EDS chemical analysis, we were able to determine that Au(core)-Pd(shell) bimetallic nanoparticles were formed. Using different computational approaches, we were capable to establish how the size of the core and the thickness of the shell will affect the thermodynamic stability of several core-shell nanoalloys. Finally, grand canonical simulations using different sampling procedures were used to study the growth mechanism of Pd atoms on Au seeds of different shape. PMID:25735727

  19. Experiments in a Perfect World:. Computer Simulations of Growth

    NASA Astrophysics Data System (ADS)

    Jensen, Pablo; Larralde, Hernán

    We present two examples of computer simulations which can give unique information on the growth mechanisms of nanostructures and thin films. First, the morphologies and the island size distributions in the usual epitaxial growth models are studied. This information cannot be obtained from simple analytical approaches such as mean-field calculations or scaling analysis. Second, we analyze a new model which includes monomer evaporation and we show that computer simulations can help deciding between different mean-field analysis and lead to the correct growth exponents.

  20. SIMPLEX: simulator and postprocessor for free-electron laser experiments

    PubMed Central

    Tanaka, Takashi

    2015-01-01

    SIMPLEX is a computer program developed for simulating the amplification process of free-electron lasers (FELs). It numerically solves the so-called FEL equations describing the evolution of the radiation field and growth of microbunching while the electron beam travels along the undulator. In order to reduce the numerical cost, the FEL equations have been reduced to more convenient forms for numerical implementation by applying reasonable approximations. SIMPLEX is equipped with a postprocessor to facilitate the retrieval of desired information from the simulation results, which is crucial for practical applications such as designing the beamline and analyzing the experimental results. PMID:26289287

  1. An obstetric simulation experience in an undergraduate nursing curriculum.

    PubMed

    Robertson, Bethany

    2006-01-01

    Educators face the dilemma of conveying didactic information in concise, creative ways that evoke critical thinking. In addition, high patient acuity, coupled with a growing nursing shortage, requires assimilation of didactic knowledge into sound clinical judgment in a timely manner. Human simulation offers a creative teaching modality that allows transference of textbook knowledge into a real-life situation where nursing students can function in their role without untoward effects to their clients. The author illustrates the use of a human birthing simulator, Noelle, in an undergraduate nursing program as a creative and effective teaching strategy.

  2. Confined granular flows on a heap: from simulations to experiments

    NASA Astrophysics Data System (ADS)

    Richard, Patrick; Valance, Alexandre; Delannay, Renaud; Boltenhagen, Philippe

    2017-06-01

    Surface granular flows are studied by means of discrete element simulations. The investigation of their kinematic properties suggests the existence of two regimes: one close to the jamming, for which the shear rate increases with the angle of the flow, and another one, far from jamming, for which the shear remains constant while the flow rate increases. Although the simulations reproduce experimental results for a given gap between sidewalls, they fail to capture the effect of confinement on the flows' properties (shear rate, flow height…).

  3. Simulations and experiments on RITA-2 at PSI

    NASA Astrophysics Data System (ADS)

    Klausen, S. N.; Lefmann, K.; McMorrow, D. F.; Altorfer, F.; Janssen, S.; Lüthy, M.

    The cold-neutron triple-axis spectrometer RITA-2 designed and built at Riso National Laboratory was installed at the neutron source SINQ at Paul Scherrer Institute in April/May 2001. In connection with the installation of RITA-2, computer simulations were performed using the neutron ray-tracing package McStas. The simulation results are compared to real experimental results obtained with a powder sample. Especially, the flux at the sample position and the resolution function of the spectrometer are investigated.

  4. Gold-palladium core@shell nanoalloys: experiments and simulations.

    PubMed

    Spitale, A; Perez, M A; Mejía-Rosales, S; Yacamán, M J; Mariscal, M M

    2015-11-14

    In this work, we report a facile synthesis route, structural characterization, and full atomistic simulations of gold-palladium nanoalloys. Through aberration corrected-STEM, UV-vis spectroscopy and EDS chemical analysis, we were able to determine that Au(core)-Pd(shell) bimetallic nanoparticles were formed. Using different computational approaches, we were capable of establishing how the size of the core and the thickness of the shell will affect the thermodynamic stability of several core-shell nanoalloys. Finally, grand canonical simulations using different sampling procedures were used to study the growth mechanism of Pd atoms on Au seeds of different shapes.

  5. SIMPLEX: simulator and postprocessor for free-electron laser experiments.

    PubMed

    Tanaka, Takashi

    2015-09-01

    SIMPLEX is a computer program developed for simulating the amplification process of free-electron lasers (FELs). It numerically solves the so-called FEL equations describing the evolution of the radiation field and growth of microbunching while the electron beam travels along the undulator. In order to reduce the numerical cost, the FEL equations have been reduced to more convenient forms for numerical implementation by applying reasonable approximations. SIMPLEX is equipped with a postprocessor to facilitate the retrieval of desired information from the simulation results, which is crucial for practical applications such as designing the beamline and analyzing the experimental results.

  6. Apollo experience report: Simulation of manned space flight for crew training

    NASA Technical Reports Server (NTRS)

    Woodling, C. H.; Faber, S.; Vanbockel, J. J.; Olasky, C. C.; Williams, W. K.; Mire, J. L. C.; Homer, J. R.

    1973-01-01

    Through space-flight experience and the development of simulators to meet the associated training requirements, several factors have been established as fundamental for providing adequate flight simulators for crew training. The development of flight simulators from Project Mercury through the Apollo 15 mission is described. The functional uses, characteristics, and development problems of the various simulators are discussed for the benefit of future programs.

  7. Kinetic simulation of direct-drive capsule implosions and its comparison with experiments and radiation hydrodynamic simulation

    NASA Astrophysics Data System (ADS)

    Kwan, Thomas; Le, Ari; Schmitt, Mark; Herrmann, Hans; Batha, Steve

    2015-11-01

    We have carried out simulations of direct-drive capsule implosion experiments conducted on Omega laser facility at the Laboratory of Laser energetics of the University of Rochester. The capsules had a glass shell (SiO2) with D, T, He-3 fills at various proportions. One-dimensional radiation hydrodynamic calculations and kinetic particle/hybrid simulations with LSP were carried out for the post-shot analysis to compare neutron yield, yield ratio, and shell convergence in assessing the effects of plasma kinetic effects. The LSP simulations were initiated with the output from the rad-hydro simulations at the end of the laser-drive. The electrons are treated as a fluid while all the ion species by the kinetic PIC technique. Our LSP simulations clearly showed species separation between the deuterons, tritons and He-3 during the implosion but significantly less after the compression. The neutron yield, gamma bang-time and -width from the LSP simulations compared favorably with experiments. Detail comparison among the kinetic simulations, rad-hydro simulations, and experimental results will be presented. Work performed under the auspices of the US Department of Energy by Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

  8. Impact of Simulation and Clinical Experience on Self-efficacy in Nursing Students: Intervention Study.

    PubMed

    Kimhi, Einat; Reishtein, Judith L; Cohen, Miri; Friger, Michael; Hurvitz, Nancy; Avraham, Rinat

    2016-01-01

    This study compared the effect of simulation and clinical experience timing on self-confidence/self-efficacy for the nursing process. Using a randomized, double-crossover design, self-efficacy was measured 3 times. Although self-efficacy was significantly higher at time 1 for students who had clinical experience, there was no difference between the groups at the end of the course (time 2). Thus, simulation increased self-confidence/self-efficacy equivalently if placed either before or after clinical experience.

  9. Computer Simulations for Lab Experiences in Secondary Physics

    ERIC Educational Resources Information Center

    Murphy, David Shannon

    2012-01-01

    Physical science instruction often involves modeling natural systems, such as electricity that possess particles which are invisible to the unaided eye. The effect of these particles' motion is observable, but the particles are not directly observable to humans. Simulations have been developed in physics, chemistry and biology that, under certain…

  10. Factors affecting species distribution predictions: A simulation modeling experiment

    Treesearch

    Gordon C. Reese; Kenneth R. Wilson; Jennifer A. Hoeting; Curtis H. Flather

    2005-01-01

    Geospatial species sample data (e.g., records with location information from natural history museums or annual surveys) are rarely collected optimally, yet are increasingly used for decisions concerning our biological heritage. Using computer simulations, we examined factors that could affect the performance of autologistic regression (ALR) models that predict species...

  11. The Land of Milk and Honey: Simulating the Immigrant Experience.

    ERIC Educational Resources Information Center

    Mahood, Wayne

    1980-01-01

    Presents details for a simulation game for a secondary social studies unit on immigration. Depending on the card a student holds, he may be allowed into the land of milk and honey, which in this game consists of graham crackers and milk. Discussion questions are included. (KC)

  12. Enhancing Lean Manufacturing Learning Experience through Hands-On Simulation

    ERIC Educational Resources Information Center

    Elbadawi, Isam; McWilliams, Douglas L.; Tetteh, Edem G.

    2010-01-01

    Finding appropriate interactive exercises to increase students' learning in technical topic courses is always challenging to educators. In this study, several paper plane hands-on simulation exercises were developed, used, and tested in a lean manufacturing course for beginning college students. A pretest and posttest was used to assess the…

  13. Simulation of Material Mixing in Shocked Gas-Curtain Experiments

    NASA Astrophysics Data System (ADS)

    Gowardhan, Akshay; Grinstein, Fernando

    2009-11-01

    The unique combination of shock and turbulence emulation capabilities supports direct use of implicit large eddy simulation (ILES) as an effective simulation anzatz in shock-driven mixing research. This possibility is demonstrated in the context of a prototypical case study for which available laboratory data can be used to test and validate the ILES modeling. An SF6 gas curtain is formed by forcing SF6 through a linear arrangement of round nozzles into the shocktube test section. The gas curtain is shocked (M=1.26, M=1.5), and its later evolution subject to Ritchmyer-Meshkov flow instabilities, transition, and non-equilibrium turbulence phenomena are investigated based on high resolution simulations for shocked and reshocked cases. The particular strategy tested here is based on a nominally-inviscid simulation model using the LANL RAGE code and adaptive mesh refinement. Initial conditions for ILES are based on emulating the physics of SF6 falling through the test section of the shock tube until a steady state is reached using a separate 3D Navier-Stokes code which solves incompressible flow in the Boussinesq approximation.

  14. Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo

    2011-01-01

    An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.

  15. Computer Simulations for Lab Experiences in Secondary Physics

    ERIC Educational Resources Information Center

    Murphy, David Shannon

    2012-01-01

    Physical science instruction often involves modeling natural systems, such as electricity that possess particles which are invisible to the unaided eye. The effect of these particles' motion is observable, but the particles are not directly observable to humans. Simulations have been developed in physics, chemistry and biology that, under certain…

  16. Critical Incidents in Counseling: Simulated Video Experiences for Training Counselors

    ERIC Educational Resources Information Center

    Spivack, James D.

    1973-01-01

    This article explains the rationale, development, and use of a simulation approach to training counselors in which videotaped vignettes of critical incidents that occur in the course of establishing and maintaining a helping relationship are presented to trainees as stimuli. (Author)

  17. Numerical Simulation of the Perrin-Like Experiments

    ERIC Educational Resources Information Center

    Mazur, Zygmunt; Grech, Dariusz

    2008-01-01

    A simple model of the random Brownian walk of a spherical mesoscopic particle in viscous liquids is proposed. The model can be solved analytically and simulated numerically. The analytic solution gives the known Einstein-Smoluchowski diffusion law r[superscript 2] = 2Dt, where the diffusion constant D is expressed by the mass and geometry of a…

  18. Group Size and Attitudes toward the Simulation Experience.

    ERIC Educational Resources Information Center

    Gentry, James W.

    1980-01-01

    A study to determine whether a relationship existed between team size and various attitudinal and performance variables in simulation games played by undergraduate business students indicated that group size had no impact on the group's performance, but that it was strongly related to the amount of dissension in the group. (LLS)

  19. Computer simulations for lab experiences in secondary physics

    NASA Astrophysics Data System (ADS)

    Murphy, David Shannon

    Physical science instruction often involves modeling natural systems, such as electricity that possess particles which are invisible to the unaided eye. The effect of these particles' motion is observable, but the particles are not directly observable to humans. Simulations have been developed in physics, chemistry and biology that, under certain circumstances, have been found to allow students to gain insight into the operation of the systems they model. This study compared the use of a DC circuit simulation, a modified simulation, static graphics, and traditional bulbs and wires to compare gains in DC circuit knowledge as measured by the DIRECT instrument, a multiple choice instrument previously developed to assess DC circuit knowledge. Gender, prior DC circuit knowledge and subsets of DC circuit knowledge of students were also compared. The population (n=166) was comprised of high school freshmen students from an eastern Kentucky public school with a population of 1100 students and followed a quantitative quasi experimental research design. Differences between treatment groups were not statistically significant. Keywords: Simulations, Static Images, Science Education, DC Circuit Instruction, Phet.

  20. The Land of Milk and Honey: Simulating the Immigrant Experience.

    ERIC Educational Resources Information Center

    Mahood, Wayne

    1980-01-01

    Presents details for a simulation game for a secondary social studies unit on immigration. Depending on the card a student holds, he may be allowed into the land of milk and honey, which in this game consists of graham crackers and milk. Discussion questions are included. (KC)